1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 88, 92-98, 1999 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 /*@@ This file should be rewritten to use an arbitrary precision
22 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
23 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
24 @@ The routines that translate from the ap rep should
25 @@ warn if precision et. al. is lost.
26 @@ This would also make life easier when this technology is used
27 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
55 static void encode
PROTO((HOST_WIDE_INT
*,
56 HOST_WIDE_INT
, HOST_WIDE_INT
));
57 static void decode
PROTO((HOST_WIDE_INT
*,
58 HOST_WIDE_INT
*, HOST_WIDE_INT
*));
59 int div_and_round_double
PROTO((enum tree_code
, int, HOST_WIDE_INT
,
60 HOST_WIDE_INT
, HOST_WIDE_INT
,
61 HOST_WIDE_INT
, HOST_WIDE_INT
*,
62 HOST_WIDE_INT
*, HOST_WIDE_INT
*,
64 static tree negate_expr
PROTO((tree
));
65 static tree split_tree
PROTO((tree
, enum tree_code
, tree
*, tree
*,
67 static tree associate_trees
PROTO((tree
, tree
, enum tree_code
, tree
));
68 static tree int_const_binop
PROTO((enum tree_code
, tree
, tree
, int, int));
69 static void const_binop_1
PROTO((PTR
));
70 static tree const_binop
PROTO((enum tree_code
, tree
, tree
, int));
71 static void fold_convert_1
PROTO((PTR
));
72 static tree fold_convert
PROTO((tree
, tree
));
73 static enum tree_code invert_tree_comparison
PROTO((enum tree_code
));
74 static enum tree_code swap_tree_comparison
PROTO((enum tree_code
));
75 static int truth_value_p
PROTO((enum tree_code
));
76 static int operand_equal_for_comparison_p
PROTO((tree
, tree
, tree
));
77 static int twoval_comparison_p
PROTO((tree
, tree
*, tree
*, int *));
78 static tree eval_subst
PROTO((tree
, tree
, tree
, tree
, tree
));
79 static tree omit_one_operand
PROTO((tree
, tree
, tree
));
80 static tree pedantic_omit_one_operand
PROTO((tree
, tree
, tree
));
81 static tree distribute_bit_expr
PROTO((enum tree_code
, tree
, tree
, tree
));
82 static tree make_bit_field_ref
PROTO((tree
, tree
, int, int, int));
83 static tree optimize_bit_field_compare
PROTO((enum tree_code
, tree
,
85 static tree decode_field_reference
PROTO((tree
, int *, int *,
86 enum machine_mode
*, int *,
87 int *, tree
*, tree
*));
88 static int all_ones_mask_p
PROTO((tree
, int));
89 static int simple_operand_p
PROTO((tree
));
90 static tree range_binop
PROTO((enum tree_code
, tree
, tree
, int,
92 static tree make_range
PROTO((tree
, int *, tree
*, tree
*));
93 static tree build_range_check
PROTO((tree
, tree
, int, tree
, tree
));
94 static int merge_ranges
PROTO((int *, tree
*, tree
*, int, tree
, tree
,
96 static tree fold_range_test
PROTO((tree
));
97 static tree unextend
PROTO((tree
, int, int, tree
));
98 static tree fold_truthop
PROTO((enum tree_code
, tree
, tree
, tree
));
99 static tree optimize_minmax_comparison
PROTO((tree
));
100 static tree extract_muldiv
PROTO((tree
, tree
, enum tree_code
, tree
));
101 static tree strip_compound_expr
PROTO((tree
, tree
));
102 static int multiple_of_p
PROTO((tree
, tree
, tree
));
103 static tree constant_boolean_node
PROTO((int, tree
));
104 static int count_cond
PROTO((tree
, int));
107 #define BRANCH_COST 1
110 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
111 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
112 and SUM1. Then this yields nonzero if overflow occurred during the
115 Overflow occurs if A and B have the same sign, but A and SUM differ in
116 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
118 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
120 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
121 We do that by representing the two-word integer in 4 words, with only
122 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
123 number. The value of the word is LOWPART + HIGHPART * BASE. */
126 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
127 #define HIGHPART(x) \
128 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
129 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
131 /* Unpack a two-word integer into 4 words.
132 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
133 WORDS points to the array of HOST_WIDE_INTs. */
136 encode (words
, low
, hi
)
137 HOST_WIDE_INT
*words
;
138 HOST_WIDE_INT low
, hi
;
140 words
[0] = LOWPART (low
);
141 words
[1] = HIGHPART (low
);
142 words
[2] = LOWPART (hi
);
143 words
[3] = HIGHPART (hi
);
146 /* Pack an array of 4 words into a two-word integer.
147 WORDS points to the array of words.
148 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
151 decode (words
, low
, hi
)
152 HOST_WIDE_INT
*words
;
153 HOST_WIDE_INT
*low
, *hi
;
155 *low
= words
[0] + words
[1] * BASE
;
156 *hi
= words
[2] + words
[3] * BASE
;
159 /* Make the integer constant T valid for its type by setting to 0 or 1 all
160 the bits in the constant that don't belong in the type.
162 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
163 nonzero, a signed overflow has already occurred in calculating T, so
166 Make the real constant T valid for its type by calling CHECK_FLOAT_VALUE,
170 force_fit_type (t
, overflow
)
174 HOST_WIDE_INT low
, high
;
177 if (TREE_CODE (t
) == REAL_CST
)
179 #ifdef CHECK_FLOAT_VALUE
180 CHECK_FLOAT_VALUE (TYPE_MODE (TREE_TYPE (t
)), TREE_REAL_CST (t
),
186 else if (TREE_CODE (t
) != INTEGER_CST
)
189 low
= TREE_INT_CST_LOW (t
);
190 high
= TREE_INT_CST_HIGH (t
);
192 if (POINTER_TYPE_P (TREE_TYPE (t
)))
195 prec
= TYPE_PRECISION (TREE_TYPE (t
));
197 /* First clear all bits that are beyond the type's precision. */
199 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
201 else if (prec
> HOST_BITS_PER_WIDE_INT
)
202 TREE_INT_CST_HIGH (t
)
203 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
206 TREE_INT_CST_HIGH (t
) = 0;
207 if (prec
< HOST_BITS_PER_WIDE_INT
)
208 TREE_INT_CST_LOW (t
) &= ~((HOST_WIDE_INT
) (-1) << prec
);
211 /* Unsigned types do not suffer sign extension or overflow. */
212 if (TREE_UNSIGNED (TREE_TYPE (t
)))
215 /* If the value's sign bit is set, extend the sign. */
216 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
217 && (prec
> HOST_BITS_PER_WIDE_INT
218 ? (TREE_INT_CST_HIGH (t
)
219 & ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
220 : TREE_INT_CST_LOW (t
) & ((HOST_WIDE_INT
) 1 << (prec
- 1))))
222 /* Value is negative:
223 set to 1 all the bits that are outside this type's precision. */
224 if (prec
> HOST_BITS_PER_WIDE_INT
)
225 TREE_INT_CST_HIGH (t
)
226 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
229 TREE_INT_CST_HIGH (t
) = -1;
230 if (prec
< HOST_BITS_PER_WIDE_INT
)
231 TREE_INT_CST_LOW (t
) |= ((HOST_WIDE_INT
) (-1) << prec
);
235 /* Return nonzero if signed overflow occurred. */
237 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
241 /* Add two doubleword integers with doubleword result.
242 Each argument is given as two `HOST_WIDE_INT' pieces.
243 One argument is L1 and H1; the other, L2 and H2.
244 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
247 add_double (l1
, h1
, l2
, h2
, lv
, hv
)
248 HOST_WIDE_INT l1
, h1
, l2
, h2
;
249 HOST_WIDE_INT
*lv
, *hv
;
254 h
= h1
+ h2
+ ((unsigned HOST_WIDE_INT
) l
< l1
);
258 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
261 /* Negate a doubleword integer with doubleword result.
262 Return nonzero if the operation overflows, assuming it's signed.
263 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
264 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
267 neg_double (l1
, h1
, lv
, hv
)
268 HOST_WIDE_INT l1
, h1
;
269 HOST_WIDE_INT
*lv
, *hv
;
275 return (*hv
& h1
) < 0;
285 /* Multiply two doubleword integers with doubleword result.
286 Return nonzero if the operation overflows, assuming it's signed.
287 Each argument is given as two `HOST_WIDE_INT' pieces.
288 One argument is L1 and H1; the other, L2 and H2.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
293 HOST_WIDE_INT l1
, h1
, l2
, h2
;
294 HOST_WIDE_INT
*lv
, *hv
;
296 HOST_WIDE_INT arg1
[4];
297 HOST_WIDE_INT arg2
[4];
298 HOST_WIDE_INT prod
[4 * 2];
299 register unsigned HOST_WIDE_INT carry
;
300 register int i
, j
, k
;
301 HOST_WIDE_INT toplow
, tophigh
, neglow
, neghigh
;
303 encode (arg1
, l1
, h1
);
304 encode (arg2
, l2
, h2
);
306 bzero ((char *) prod
, sizeof prod
);
308 for (i
= 0; i
< 4; i
++)
311 for (j
= 0; j
< 4; j
++)
314 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
315 carry
+= arg1
[i
] * arg2
[j
];
316 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
318 prod
[k
] = LOWPART (carry
);
319 carry
= HIGHPART (carry
);
324 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
326 /* Check for overflow by calculating the top half of the answer in full;
327 it should agree with the low half's sign bit. */
328 decode (prod
+4, &toplow
, &tophigh
);
331 neg_double (l2
, h2
, &neglow
, &neghigh
);
332 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
336 neg_double (l1
, h1
, &neglow
, &neghigh
);
337 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
339 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
342 /* Shift the doubleword integer in L1, H1 left by COUNT places
343 keeping only PREC bits of result.
344 Shift right if COUNT is negative.
345 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
346 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
349 lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
350 HOST_WIDE_INT l1
, h1
, count
;
352 HOST_WIDE_INT
*lv
, *hv
;
357 rshift_double (l1
, h1
, - count
, prec
, lv
, hv
, arith
);
361 #ifdef SHIFT_COUNT_TRUNCATED
362 if (SHIFT_COUNT_TRUNCATED
)
366 if (count
>= HOST_BITS_PER_WIDE_INT
)
368 *hv
= (unsigned HOST_WIDE_INT
) l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
373 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
374 | ((unsigned HOST_WIDE_INT
) l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
375 *lv
= (unsigned HOST_WIDE_INT
) l1
<< count
;
379 /* Shift the doubleword integer in L1, H1 right by COUNT places
380 keeping only PREC bits of result. COUNT must be positive.
381 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
382 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
385 rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
386 HOST_WIDE_INT l1
, h1
, count
;
387 int prec ATTRIBUTE_UNUSED
;
388 HOST_WIDE_INT
*lv
, *hv
;
391 unsigned HOST_WIDE_INT signmask
;
393 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
396 #ifdef SHIFT_COUNT_TRUNCATED
397 if (SHIFT_COUNT_TRUNCATED
)
401 if (count
>= HOST_BITS_PER_WIDE_INT
)
404 *lv
= ((signmask
<< (2 * HOST_BITS_PER_WIDE_INT
- count
- 1) << 1)
405 | ((unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
)));
409 *lv
= (((unsigned HOST_WIDE_INT
) l1
>> count
)
410 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
411 *hv
= ((signmask
<< (HOST_BITS_PER_WIDE_INT
- count
))
412 | ((unsigned HOST_WIDE_INT
) h1
>> count
));
416 /* Rotate the doubleword integer in L1, H1 left by COUNT places
417 keeping only PREC bits of result.
418 Rotate right if COUNT is negative.
419 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
422 lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
423 HOST_WIDE_INT l1
, h1
, count
;
425 HOST_WIDE_INT
*lv
, *hv
;
427 HOST_WIDE_INT s1l
, s1h
, s2l
, s2h
;
433 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
434 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
439 /* Rotate the doubleword integer in L1, H1 left by COUNT places
440 keeping only PREC bits of result. COUNT must be positive.
441 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
444 rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
445 HOST_WIDE_INT l1
, h1
, count
;
447 HOST_WIDE_INT
*lv
, *hv
;
449 HOST_WIDE_INT s1l
, s1h
, s2l
, s2h
;
455 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
456 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
461 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
462 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
463 CODE is a tree code for a kind of division, one of
464 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
466 It controls how the quotient is rounded to a integer.
467 Return nonzero if the operation overflows.
468 UNS nonzero says do unsigned division. */
471 div_and_round_double (code
, uns
,
472 lnum_orig
, hnum_orig
, lden_orig
, hden_orig
,
473 lquo
, hquo
, lrem
, hrem
)
476 HOST_WIDE_INT lnum_orig
, hnum_orig
; /* num == numerator == dividend */
477 HOST_WIDE_INT lden_orig
, hden_orig
; /* den == denominator == divisor */
478 HOST_WIDE_INT
*lquo
, *hquo
, *lrem
, *hrem
;
481 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
482 HOST_WIDE_INT den
[4], quo
[4];
484 unsigned HOST_WIDE_INT work
;
485 register unsigned HOST_WIDE_INT carry
= 0;
486 HOST_WIDE_INT lnum
= lnum_orig
;
487 HOST_WIDE_INT hnum
= hnum_orig
;
488 HOST_WIDE_INT lden
= lden_orig
;
489 HOST_WIDE_INT hden
= hden_orig
;
492 if ((hden
== 0) && (lden
== 0))
493 overflow
= 1, lden
= 1;
495 /* calculate quotient sign and convert operands to unsigned. */
501 /* (minimum integer) / (-1) is the only overflow case. */
502 if (neg_double (lnum
, hnum
, &lnum
, &hnum
) && (lden
& hden
) == -1)
508 neg_double (lden
, hden
, &lden
, &hden
);
512 if (hnum
== 0 && hden
== 0)
513 { /* single precision */
515 /* This unsigned division rounds toward zero. */
516 *lquo
= lnum
/ (unsigned HOST_WIDE_INT
) lden
;
521 { /* trivial case: dividend < divisor */
522 /* hden != 0 already checked. */
529 bzero ((char *) quo
, sizeof quo
);
531 bzero ((char *) num
, sizeof num
); /* to zero 9th element */
532 bzero ((char *) den
, sizeof den
);
534 encode (num
, lnum
, hnum
);
535 encode (den
, lden
, hden
);
537 /* Special code for when the divisor < BASE. */
538 if (hden
== 0 && lden
< (HOST_WIDE_INT
) BASE
)
540 /* hnum != 0 already checked. */
541 for (i
= 4 - 1; i
>= 0; i
--)
543 work
= num
[i
] + carry
* BASE
;
544 quo
[i
] = work
/ (unsigned HOST_WIDE_INT
) lden
;
545 carry
= work
% (unsigned HOST_WIDE_INT
) lden
;
550 /* Full double precision division,
551 with thanks to Don Knuth's "Seminumerical Algorithms". */
552 int num_hi_sig
, den_hi_sig
;
553 unsigned HOST_WIDE_INT quo_est
, scale
;
555 /* Find the highest non-zero divisor digit. */
556 for (i
= 4 - 1; ; i
--)
562 /* Insure that the first digit of the divisor is at least BASE/2.
563 This is required by the quotient digit estimation algorithm. */
565 scale
= BASE
/ (den
[den_hi_sig
] + 1);
566 if (scale
> 1) { /* scale divisor and dividend */
568 for (i
= 0; i
<= 4 - 1; i
++) {
569 work
= (num
[i
] * scale
) + carry
;
570 num
[i
] = LOWPART (work
);
571 carry
= HIGHPART (work
);
574 for (i
= 0; i
<= 4 - 1; i
++) {
575 work
= (den
[i
] * scale
) + carry
;
576 den
[i
] = LOWPART (work
);
577 carry
= HIGHPART (work
);
578 if (den
[i
] != 0) den_hi_sig
= i
;
585 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--) {
586 /* guess the next quotient digit, quo_est, by dividing the first
587 two remaining dividend digits by the high order quotient digit.
588 quo_est is never low and is at most 2 high. */
589 unsigned HOST_WIDE_INT tmp
;
591 num_hi_sig
= i
+ den_hi_sig
+ 1;
592 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
593 if (num
[num_hi_sig
] != den
[den_hi_sig
])
594 quo_est
= work
/ den
[den_hi_sig
];
598 /* refine quo_est so it's usually correct, and at most one high. */
599 tmp
= work
- quo_est
* den
[den_hi_sig
];
601 && den
[den_hi_sig
- 1] * quo_est
> (tmp
* BASE
+ num
[num_hi_sig
- 2]))
604 /* Try QUO_EST as the quotient digit, by multiplying the
605 divisor by QUO_EST and subtracting from the remaining dividend.
606 Keep in mind that QUO_EST is the I - 1st digit. */
609 for (j
= 0; j
<= den_hi_sig
; j
++)
611 work
= quo_est
* den
[j
] + carry
;
612 carry
= HIGHPART (work
);
613 work
= num
[i
+ j
] - LOWPART (work
);
614 num
[i
+ j
] = LOWPART (work
);
615 carry
+= HIGHPART (work
) != 0;
618 /* if quo_est was high by one, then num[i] went negative and
619 we need to correct things. */
621 if (num
[num_hi_sig
] < carry
)
624 carry
= 0; /* add divisor back in */
625 for (j
= 0; j
<= den_hi_sig
; j
++)
627 work
= num
[i
+ j
] + den
[j
] + carry
;
628 carry
= HIGHPART (work
);
629 num
[i
+ j
] = LOWPART (work
);
631 num
[num_hi_sig
] += carry
;
634 /* store the quotient digit. */
639 decode (quo
, lquo
, hquo
);
642 /* if result is negative, make it so. */
644 neg_double (*lquo
, *hquo
, lquo
, hquo
);
646 /* compute trial remainder: rem = num - (quo * den) */
647 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
648 neg_double (*lrem
, *hrem
, lrem
, hrem
);
649 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
654 case TRUNC_MOD_EXPR
: /* round toward zero */
655 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
659 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
660 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
663 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
666 else return overflow
;
670 case CEIL_MOD_EXPR
: /* round toward positive infinity */
671 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
673 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
676 else return overflow
;
680 case ROUND_MOD_EXPR
: /* round to closest integer */
682 HOST_WIDE_INT labs_rem
= *lrem
, habs_rem
= *hrem
;
683 HOST_WIDE_INT labs_den
= lden
, habs_den
= hden
, ltwice
, htwice
;
685 /* get absolute values */
686 if (*hrem
< 0) neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
687 if (hden
< 0) neg_double (lden
, hden
, &labs_den
, &habs_den
);
689 /* if (2 * abs (lrem) >= abs (lden)) */
690 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
691 labs_rem
, habs_rem
, <wice
, &htwice
);
692 if (((unsigned HOST_WIDE_INT
) habs_den
693 < (unsigned HOST_WIDE_INT
) htwice
)
694 || (((unsigned HOST_WIDE_INT
) habs_den
695 == (unsigned HOST_WIDE_INT
) htwice
)
696 && ((HOST_WIDE_INT
unsigned) labs_den
697 < (unsigned HOST_WIDE_INT
) ltwice
)))
701 add_double (*lquo
, *hquo
,
702 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
705 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
708 else return overflow
;
716 /* compute true remainder: rem = num - (quo * den) */
717 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
718 neg_double (*lrem
, *hrem
, lrem
, hrem
);
719 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
723 #ifndef REAL_ARITHMETIC
724 /* Effectively truncate a real value to represent the nearest possible value
725 in a narrower mode. The result is actually represented in the same data
726 type as the argument, but its value is usually different.
728 A trap may occur during the FP operations and it is the responsibility
729 of the calling function to have a handler established. */
732 real_value_truncate (mode
, arg
)
733 enum machine_mode mode
;
736 return REAL_VALUE_TRUNCATE (mode
, arg
);
739 #if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
741 /* Check for infinity in an IEEE double precision number. */
747 /* The IEEE 64-bit double format. */
752 unsigned exponent
: 11;
753 unsigned mantissa1
: 20;
758 unsigned mantissa1
: 20;
759 unsigned exponent
: 11;
765 if (u
.big_endian
.sign
== 1)
768 return (u
.big_endian
.exponent
== 2047
769 && u
.big_endian
.mantissa1
== 0
770 && u
.big_endian
.mantissa2
== 0);
775 return (u
.little_endian
.exponent
== 2047
776 && u
.little_endian
.mantissa1
== 0
777 && u
.little_endian
.mantissa2
== 0);
781 /* Check whether an IEEE double precision number is a NaN. */
787 /* The IEEE 64-bit double format. */
792 unsigned exponent
: 11;
793 unsigned mantissa1
: 20;
798 unsigned mantissa1
: 20;
799 unsigned exponent
: 11;
805 if (u
.big_endian
.sign
== 1)
808 return (u
.big_endian
.exponent
== 2047
809 && (u
.big_endian
.mantissa1
!= 0
810 || u
.big_endian
.mantissa2
!= 0));
815 return (u
.little_endian
.exponent
== 2047
816 && (u
.little_endian
.mantissa1
!= 0
817 || u
.little_endian
.mantissa2
!= 0));
821 /* Check for a negative IEEE double precision number. */
827 /* The IEEE 64-bit double format. */
832 unsigned exponent
: 11;
833 unsigned mantissa1
: 20;
838 unsigned mantissa1
: 20;
839 unsigned exponent
: 11;
845 if (u
.big_endian
.sign
== 1)
848 return u
.big_endian
.sign
;
853 return u
.little_endian
.sign
;
856 #else /* Target not IEEE */
858 /* Let's assume other float formats don't have infinity.
859 (This can be overridden by redefining REAL_VALUE_ISINF.) */
868 /* Let's assume other float formats don't have NaNs.
869 (This can be overridden by redefining REAL_VALUE_ISNAN.) */
878 /* Let's assume other float formats don't have minus zero.
879 (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
887 #endif /* Target not IEEE */
889 /* Try to change R into its exact multiplicative inverse in machine mode
890 MODE. Return nonzero function value if successful. */
893 exact_real_inverse (mode
, r
)
894 enum machine_mode mode
;
905 /* Usually disable if bounds checks are not reliable. */
906 if ((HOST_FLOAT_FORMAT
!= TARGET_FLOAT_FORMAT
) && !flag_pretend_float
)
909 /* Set array index to the less significant bits in the unions, depending
910 on the endian-ness of the host doubles.
911 Disable if insufficient information on the data structure. */
912 #if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
915 #if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT
918 #if HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
921 #define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
926 if (setjmp (float_error
))
928 /* Don't do the optimization if there was an arithmetic error. */
930 set_float_handler (NULL_PTR
);
933 set_float_handler (float_error
);
935 /* Domain check the argument. */
941 if (REAL_VALUE_ISINF (x
.d
) || REAL_VALUE_ISNAN (x
.d
))
945 /* Compute the reciprocal and check for numerical exactness.
946 It is unnecessary to check all the significand bits to determine
947 whether X is a power of 2. If X is not, then it is impossible for
948 the bottom half significand of both X and 1/X to be all zero bits.
949 Hence we ignore the data structure of the top half and examine only
950 the low order bits of the two significands. */
952 if (x
.i
[K
] != 0 || x
.i
[K
+ 1] != 0 || t
.i
[K
] != 0 || t
.i
[K
+ 1] != 0)
955 /* Truncate to the required mode and range-check the result. */
956 y
.d
= REAL_VALUE_TRUNCATE (mode
, t
.d
);
957 #ifdef CHECK_FLOAT_VALUE
959 if (CHECK_FLOAT_VALUE (mode
, y
.d
, i
))
963 /* Fail if truncation changed the value. */
964 if (y
.d
!= t
.d
|| y
.d
== 0.0)
968 if (REAL_VALUE_ISINF (y
.d
) || REAL_VALUE_ISNAN (y
.d
))
972 /* Output the reciprocal and return success flag. */
973 set_float_handler (NULL_PTR
);
978 /* Convert C9X hexadecimal floating point string constant S. Return
979 real value type in mode MODE. This function uses the host computer's
980 floating point arithmetic when there is no REAL_ARITHMETIC. */
983 real_hex_to_f (s
, mode
)
985 enum machine_mode mode
;
989 unsigned HOST_WIDE_INT low
, high
;
990 int expon
, shcount
, nrmcount
, k
;
991 int sign
, expsign
, isfloat
, isldouble
;
992 int lost
= 0;/* Nonzero low order bits shifted out and discarded. */
993 int frexpon
= 0; /* Bits after the decimal point. */
994 int expon
= 0; /* Value of exponent. */
995 int decpt
= 0; /* How many decimal points. */
996 int gotp
= 0; /* How many P's. */
1006 while (*p
== ' ' || *p
== '\t')
1009 /* Sign, if any, comes first. */
1017 /* The string is supposed to start with 0x or 0X . */
1021 if (*p
== 'x' || *p
== 'X')
1035 while ((c
= *p
) != '\0')
1037 if ((c
>= '0' && c
<= '9') || (c
>= 'A' && c
<= 'F')
1038 || (c
>= 'a' && c
<= 'f'))
1048 if ((high
& 0xf0000000) == 0)
1050 high
= (high
<< 4) + ((low
>> 28) & 15);
1051 low
= (low
<< 4) + k
;
1058 /* Record nonzero lost bits. */
1071 else if (c
== 'p' || c
== 'P')
1075 /* Sign of exponent. */
1082 /* Value of exponent.
1083 The exponent field is a decimal integer. */
1086 k
= (*p
++ & 0x7f) - '0';
1087 expon
= 10 * expon
+ k
;
1091 /* F suffix is ambiguous in the significand part
1092 so it must appear after the decimal exponent field. */
1093 if (*p
== 'f' || *p
== 'F')
1101 else if (c
== 'l' || c
== 'L')
1111 /* Abort if last character read was not legitimate. */
1113 if ((c
!= '\0' && c
!= ' ' && c
!= '\n' && c
!= '\r') || (decpt
> 1))
1116 /* There must be either one decimal point or one p. */
1117 if (decpt
== 0 && gotp
== 0)
1121 if (high
== 0 && low
== 0)
1133 /* Leave a high guard bit for carry-out. */
1134 if ((high
& 0x80000000) != 0)
1137 low
= (low
>> 1) | (high
<< 31);
1142 if ((high
& 0xffff8000) == 0)
1144 high
= (high
<< 16) + ((low
>> 16) & 0xffff);
1149 while ((high
& 0xc0000000) == 0)
1151 high
= (high
<< 1) + ((low
>> 31) & 1);
1156 if (isfloat
|| GET_MODE_SIZE(mode
) == UNITS_PER_WORD
)
1158 /* Keep 24 bits precision, bits 0x7fffff80.
1159 Rounding bit is 0x40. */
1160 lost
= lost
| low
| (high
& 0x3f);
1164 if ((high
& 0x80) || lost
)
1171 /* We need real.c to do long double formats, so here default
1172 to double precision. */
1173 #if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
1175 Keep 53 bits precision, bits 0x7fffffff fffffc00.
1176 Rounding bit is low word 0x200. */
1177 lost
= lost
| (low
& 0x1ff);
1180 if ((low
& 0x400) || lost
)
1182 low
= (low
+ 0x200) & 0xfffffc00;
1189 /* Assume it's a VAX with 56-bit significand,
1190 bits 0x7fffffff ffffff80. */
1191 lost
= lost
| (low
& 0x7f);
1194 if ((low
& 0x80) || lost
)
1196 low
= (low
+ 0x40) & 0xffffff80;
1206 ip
= REAL_VALUE_LDEXP (ip
, 32) + (double) low
;
1207 /* Apply shifts and exponent value as power of 2. */
1208 ip
= REAL_VALUE_LDEXP (ip
, expon
- (nrmcount
+ frexpon
));
1215 #endif /* no REAL_ARITHMETIC */
1217 /* Given T, an expression, return the negation of T. Allow for T to be
1218 null, in which case return null. */
1230 type
= TREE_TYPE (t
);
1231 STRIP_SIGN_NOPS (t
);
1233 switch (TREE_CODE (t
))
1237 if (! TREE_UNSIGNED (type
)
1238 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
1239 && ! TREE_OVERFLOW (tem
))
1244 return convert (type
, TREE_OPERAND (t
, 0));
1247 /* - (A - B) -> B - A */
1248 if (! FLOAT_TYPE_P (type
) || flag_fast_math
)
1249 return convert (type
,
1250 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
1251 TREE_OPERAND (t
, 1),
1252 TREE_OPERAND (t
, 0))));
1259 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
));
1262 /* Split a tree IN into a constant, literal and variable parts that could be
1263 combined with CODE to make IN. "constant" means an expression with
1264 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1265 commutative arithmetic operation. Store the constant part into *CONP,
1266 the literal in &LITP and return the variable part. If a part isn't
1267 present, set it to null. If the tree does not decompose in this way,
1268 return the entire tree as the variable part and the other parts as null.
1270 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
1271 case, we negate an operand that was subtracted. If NEGATE_P is true, we
1272 are negating all of IN.
1274 If IN is itself a literal or constant, return it as appropriate.
1276 Note that we do not guarantee that any of the three values will be the
1277 same type as IN, but they will have the same signedness and mode. */
1280 split_tree (in
, code
, conp
, litp
, negate_p
)
1282 enum tree_code code
;
1291 /* Strip any conversions that don't change the machine mode or signedness. */
1292 STRIP_SIGN_NOPS (in
);
1294 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
1296 else if (TREE_CONSTANT (in
))
1299 else if (TREE_CODE (in
) == code
1300 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
1301 /* We can associate addition and subtraction together (even
1302 though the C standard doesn't say so) for integers because
1303 the value is not affected. For reals, the value might be
1304 affected, so we can't. */
1305 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
1306 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
1308 tree op0
= TREE_OPERAND (in
, 0);
1309 tree op1
= TREE_OPERAND (in
, 1);
1310 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
1311 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
1313 /* First see if either of the operands is a literal, then a constant. */
1314 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
1315 *litp
= op0
, op0
= 0;
1316 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
1317 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
1319 if (op0
!= 0 && TREE_CONSTANT (op0
))
1320 *conp
= op0
, op0
= 0;
1321 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1322 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1324 /* If we haven't dealt with either operand, this is not a case we can
1325 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1326 if (op0
!= 0 && op1
!= 0)
1331 var
= op1
, neg_var_p
= neg1_p
;
1333 /* Now do any needed negations. */
1334 if (neg_litp_p
) *litp
= negate_expr (*litp
);
1335 if (neg_conp_p
) *conp
= negate_expr (*conp
);
1336 if (neg_var_p
) var
= negate_expr (var
);
1343 var
= negate_expr (var
);
1344 *conp
= negate_expr (*conp
);
1345 *litp
= negate_expr (*litp
);
1351 /* Re-associate trees split by the above function. T1 and T2 are either
1352 expressions to associate or null. Return the new expression, if any. If
1353 we build an operation, do it in TYPE and with CODE, except if CODE is a
1354 MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
1355 have taken care of the negations. */
1358 associate_trees (t1
, t2
, code
, type
)
1360 enum tree_code code
;
1368 if (code
== MINUS_EXPR
)
1371 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1372 try to fold this since we will have infinite recursion. But do
1373 deal with any NEGATE_EXPRs. */
1374 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1375 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1377 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1378 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1379 convert (type
, TREE_OPERAND (t1
, 0)));
1380 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1381 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1382 convert (type
, TREE_OPERAND (t2
, 0)));
1384 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1387 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1390 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1391 to produce a new constant.
1393 If NOTRUNC is nonzero, do not truncate the result to fit the data type.
1394 If FORSIZE is nonzero, compute overflow for unsigned types. */
1397 int_const_binop (code
, arg1
, arg2
, notrunc
, forsize
)
1398 enum tree_code code
;
1399 register tree arg1
, arg2
;
1400 int notrunc
, forsize
;
1402 HOST_WIDE_INT int1l
, int1h
, int2l
, int2h
;
1403 HOST_WIDE_INT low
, hi
;
1404 HOST_WIDE_INT garbagel
, garbageh
;
1406 int uns
= TREE_UNSIGNED (TREE_TYPE (arg1
));
1408 int no_overflow
= 0;
1410 int1l
= TREE_INT_CST_LOW (arg1
);
1411 int1h
= TREE_INT_CST_HIGH (arg1
);
1412 int2l
= TREE_INT_CST_LOW (arg2
);
1413 int2h
= TREE_INT_CST_HIGH (arg2
);
1418 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1422 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1426 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1429 case BIT_ANDTC_EXPR
:
1430 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1436 /* It's unclear from the C standard whether shifts can overflow.
1437 The following code ignores overflow; perhaps a C standard
1438 interpretation ruling is needed. */
1439 lshift_double (int1l
, int1h
, int2l
,
1440 TYPE_PRECISION (TREE_TYPE (arg1
)),
1449 lrotate_double (int1l
, int1h
, int2l
,
1450 TYPE_PRECISION (TREE_TYPE (arg1
)),
1455 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1459 neg_double (int2l
, int2h
, &low
, &hi
);
1460 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1461 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1465 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1468 case TRUNC_DIV_EXPR
:
1469 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1470 case EXACT_DIV_EXPR
:
1471 /* This is a shortcut for a common special case. */
1472 if (int2h
== 0 && int2l
> 0
1473 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1474 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1475 && int1h
== 0 && int1l
>= 0)
1477 if (code
== CEIL_DIV_EXPR
)
1479 low
= int1l
/ int2l
, hi
= 0;
1483 /* ... fall through ... */
1485 case ROUND_DIV_EXPR
:
1486 if (int2h
== 0 && int2l
== 1)
1488 low
= int1l
, hi
= int1h
;
1491 if (int1l
== int2l
&& int1h
== int2h
1492 && ! (int1l
== 0 && int1h
== 0))
1497 overflow
= div_and_round_double (code
, uns
,
1498 int1l
, int1h
, int2l
, int2h
,
1499 &low
, &hi
, &garbagel
, &garbageh
);
1502 case TRUNC_MOD_EXPR
:
1503 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1504 /* This is a shortcut for a common special case. */
1505 if (int2h
== 0 && int2l
> 0
1506 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1507 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1508 && int1h
== 0 && int1l
>= 0)
1510 if (code
== CEIL_MOD_EXPR
)
1512 low
= int1l
% int2l
, hi
= 0;
1516 /* ... fall through ... */
1518 case ROUND_MOD_EXPR
:
1519 overflow
= div_and_round_double (code
, uns
,
1520 int1l
, int1h
, int2l
, int2h
,
1521 &garbagel
, &garbageh
, &low
, &hi
);
1527 low
= (((unsigned HOST_WIDE_INT
) int1h
1528 < (unsigned HOST_WIDE_INT
) int2h
)
1529 || (((unsigned HOST_WIDE_INT
) int1h
1530 == (unsigned HOST_WIDE_INT
) int2h
)
1531 && ((unsigned HOST_WIDE_INT
) int1l
1532 < (unsigned HOST_WIDE_INT
) int2l
)));
1534 low
= ((int1h
< int2h
)
1535 || ((int1h
== int2h
)
1536 && ((unsigned HOST_WIDE_INT
) int1l
1537 < (unsigned HOST_WIDE_INT
) int2l
)));
1539 if (low
== (code
== MIN_EXPR
))
1540 low
= int1l
, hi
= int1h
;
1542 low
= int2l
, hi
= int2h
;
1549 if (TREE_TYPE (arg1
) == sizetype
&& hi
== 0
1551 && (TYPE_MAX_VALUE (sizetype
) == NULL
1552 || low
<= TREE_INT_CST_LOW (TYPE_MAX_VALUE (sizetype
)))
1554 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1558 t
= build_int_2 (low
, hi
);
1559 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1563 = ((notrunc
? (!uns
|| forsize
) && overflow
1564 : force_fit_type (t
, (!uns
|| forsize
) && overflow
) && ! no_overflow
)
1565 | TREE_OVERFLOW (arg1
)
1566 | TREE_OVERFLOW (arg2
));
1568 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1569 So check if force_fit_type truncated the value. */
1571 && ! TREE_OVERFLOW (t
)
1572 && (TREE_INT_CST_HIGH (t
) != hi
1573 || TREE_INT_CST_LOW (t
) != low
))
1574 TREE_OVERFLOW (t
) = 1;
1576 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1577 | TREE_CONSTANT_OVERFLOW (arg1
)
1578 | TREE_CONSTANT_OVERFLOW (arg2
));
1582 /* Define input and output argument for const_binop_1. */
1585 enum tree_code code
; /* Input: tree code for operation*/
1586 tree type
; /* Input: tree type for operation. */
1587 REAL_VALUE_TYPE d1
, d2
; /* Input: floating point operands. */
1588 tree t
; /* Output: constant for result. */
1591 /* Do the real arithmetic for const_binop while protected by a
1592 float overflow handler. */
1595 const_binop_1 (data
)
1598 struct cb_args
*args
= (struct cb_args
*) data
;
1599 REAL_VALUE_TYPE value
;
1601 #ifdef REAL_ARITHMETIC
1602 REAL_ARITHMETIC (value
, args
->code
, args
->d1
, args
->d2
);
1607 value
= args
->d1
+ args
->d2
;
1611 value
= args
->d1
- args
->d2
;
1615 value
= args
->d1
* args
->d2
;
1619 #ifndef REAL_INFINITY
1624 value
= args
->d1
/ args
->d2
;
1628 value
= MIN (args
->d1
, args
->d2
);
1632 value
= MAX (args
->d1
, args
->d2
);
1638 #endif /* no REAL_ARITHMETIC */
1641 = build_real (args
->type
,
1642 real_value_truncate (TYPE_MODE (args
->type
), value
));
1645 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1646 constant. We assume ARG1 and ARG2 have the same data type, or at least
1647 are the same kind of constant and the same machine mode.
1649 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1652 const_binop (code
, arg1
, arg2
, notrunc
)
1653 enum tree_code code
;
1654 register tree arg1
, arg2
;
1657 STRIP_NOPS (arg1
); STRIP_NOPS (arg2
);
1659 if (TREE_CODE (arg1
) == INTEGER_CST
)
1660 return int_const_binop (code
, arg1
, arg2
, notrunc
, 0);
1662 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1663 if (TREE_CODE (arg1
) == REAL_CST
)
1669 struct cb_args args
;
1671 d1
= TREE_REAL_CST (arg1
);
1672 d2
= TREE_REAL_CST (arg2
);
1674 /* If either operand is a NaN, just return it. Otherwise, set up
1675 for floating-point trap; we return an overflow. */
1676 if (REAL_VALUE_ISNAN (d1
))
1678 else if (REAL_VALUE_ISNAN (d2
))
1681 /* Setup input for const_binop_1() */
1682 args
.type
= TREE_TYPE (arg1
);
1687 if (do_float_handler (const_binop_1
, (PTR
) &args
))
1688 /* Receive output from const_binop_1. */
1692 /* We got an exception from const_binop_1. */
1693 t
= copy_node (arg1
);
1698 = (force_fit_type (t
, overflow
)
1699 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1700 TREE_CONSTANT_OVERFLOW (t
)
1702 | TREE_CONSTANT_OVERFLOW (arg1
)
1703 | TREE_CONSTANT_OVERFLOW (arg2
);
1706 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
1707 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1709 register tree type
= TREE_TYPE (arg1
);
1710 register tree r1
= TREE_REALPART (arg1
);
1711 register tree i1
= TREE_IMAGPART (arg1
);
1712 register tree r2
= TREE_REALPART (arg2
);
1713 register tree i2
= TREE_IMAGPART (arg2
);
1719 t
= build_complex (type
,
1720 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1721 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1725 t
= build_complex (type
,
1726 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1727 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1731 t
= build_complex (type
,
1732 const_binop (MINUS_EXPR
,
1733 const_binop (MULT_EXPR
,
1735 const_binop (MULT_EXPR
,
1738 const_binop (PLUS_EXPR
,
1739 const_binop (MULT_EXPR
,
1741 const_binop (MULT_EXPR
,
1748 register tree magsquared
1749 = const_binop (PLUS_EXPR
,
1750 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1751 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1754 t
= build_complex (type
,
1756 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1757 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1758 const_binop (PLUS_EXPR
,
1759 const_binop (MULT_EXPR
, r1
, r2
,
1761 const_binop (MULT_EXPR
, i1
, i2
,
1764 magsquared
, notrunc
),
1766 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1767 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1768 const_binop (MINUS_EXPR
,
1769 const_binop (MULT_EXPR
, i1
, r2
,
1771 const_binop (MULT_EXPR
, r1
, i2
,
1774 magsquared
, notrunc
));
1786 /* Return an INTEGER_CST with value whose HOST_BITS_PER_WIDE_INT bits are
1787 given by HIGH and whose HOST_BITS_PER_WIDE_INT bits are given by NUMBER.
1789 If BIT_P is nonzero, this represents a size in bit and the type of the
1790 result will be bitsizetype, othewise it represents a size in bytes and
1791 the type of the result will be sizetype. */
1794 size_int_wide (number
, high
, bit_p
)
1795 unsigned HOST_WIDE_INT number
, high
;
1798 /* Type-size nodes already made for small sizes. */
1799 static tree size_table
[2 * HOST_BITS_PER_WIDE_INT
+ 1][2];
1800 static int init_p
= 0;
1803 if (ggc_p
&& ! init_p
)
1805 ggc_add_tree_root ((tree
*) size_table
,
1806 sizeof size_table
/ sizeof (tree
));
1810 if (number
< 2*HOST_BITS_PER_WIDE_INT
+ 1 && high
== 0
1811 && size_table
[number
][bit_p
] != 0)
1812 return size_table
[number
][bit_p
];
1814 if (number
< 2*HOST_BITS_PER_WIDE_INT
+ 1 && high
== 0)
1818 /* Make this a permanent node. */
1819 push_obstacks_nochange ();
1820 end_temporary_allocation ();
1823 t
= build_int_2 (number
, 0);
1824 TREE_TYPE (t
) = bit_p
? bitsizetype
: sizetype
;
1825 size_table
[number
][bit_p
] = t
;
1833 t
= build_int_2 (number
, high
);
1834 TREE_TYPE (t
) = bit_p
? bitsizetype
: sizetype
;
1835 TREE_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (t
) = force_fit_type (t
, 0);
1839 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1840 CODE is a tree code. Data type is taken from `sizetype',
1841 If the operands are constant, so is the result. */
1844 size_binop (code
, arg0
, arg1
)
1845 enum tree_code code
;
1848 /* Handle the special case of two integer constants faster. */
1849 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1851 /* And some specific cases even faster than that. */
1852 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1854 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1855 && integer_zerop (arg1
))
1857 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1860 /* Handle general case of two integer constants. */
1861 return int_const_binop (code
, arg0
, arg1
, 0, 1);
1864 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1865 return error_mark_node
;
1867 return fold (build (code
, sizetype
, arg0
, arg1
));
1870 /* Combine operands OP1 and OP2 with arithmetic operation CODE.
1871 CODE is a tree code. Data type is taken from `ssizetype',
1872 If the operands are constant, so is the result. */
1875 ssize_binop (code
, arg0
, arg1
)
1876 enum tree_code code
;
1879 /* Handle the special case of two integer constants faster. */
1880 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1882 /* And some specific cases even faster than that. */
1883 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1885 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1886 && integer_zerop (arg1
))
1888 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1891 /* Handle general case of two integer constants. We convert
1892 arg0 to ssizetype because int_const_binop uses its type for the
1894 arg0
= convert (ssizetype
, arg0
);
1895 return int_const_binop (code
, arg0
, arg1
, 0, 0);
1898 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1899 return error_mark_node
;
1901 return fold (build (code
, ssizetype
, arg0
, arg1
));
1904 /* This structure is used to communicate arguments to fold_convert_1. */
1907 tree arg1
; /* Input: value to convert. */
1908 tree type
; /* Input: type to convert value to. */
1909 tree t
; /* Ouput: result of conversion. */
1912 /* Function to convert floating-point constants, protected by floating
1913 point exception handler. */
1916 fold_convert_1 (data
)
1919 struct fc_args
* args
= (struct fc_args
*) data
;
1921 args
->t
= build_real (args
->type
,
1922 real_value_truncate (TYPE_MODE (args
->type
),
1923 TREE_REAL_CST (args
->arg1
)));
1926 /* Given T, a tree representing type conversion of ARG1, a constant,
1927 return a constant tree representing the result of conversion. */
1930 fold_convert (t
, arg1
)
1934 register tree type
= TREE_TYPE (t
);
1937 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1939 if (TREE_CODE (arg1
) == INTEGER_CST
)
1941 /* If we would build a constant wider than GCC supports,
1942 leave the conversion unfolded. */
1943 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1946 /* Given an integer constant, make new constant with new type,
1947 appropriately sign-extended or truncated. */
1948 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1949 TREE_INT_CST_HIGH (arg1
));
1950 TREE_TYPE (t
) = type
;
1951 /* Indicate an overflow if (1) ARG1 already overflowed,
1952 or (2) force_fit_type indicates an overflow.
1953 Tell force_fit_type that an overflow has already occurred
1954 if ARG1 is a too-large unsigned value and T is signed.
1955 But don't indicate an overflow if converting a pointer. */
1957 = ((force_fit_type (t
,
1958 (TREE_INT_CST_HIGH (arg1
) < 0
1959 && (TREE_UNSIGNED (type
)
1960 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1961 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1962 || TREE_OVERFLOW (arg1
));
1963 TREE_CONSTANT_OVERFLOW (t
)
1964 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1966 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
1967 else if (TREE_CODE (arg1
) == REAL_CST
)
1969 /* Don't initialize these, use assignments.
1970 Initialized local aggregates don't work on old compilers. */
1974 tree type1
= TREE_TYPE (arg1
);
1977 x
= TREE_REAL_CST (arg1
);
1978 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1980 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1981 if (!no_upper_bound
)
1982 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1984 /* See if X will be in range after truncation towards 0.
1985 To compensate for truncation, move the bounds away from 0,
1986 but reject if X exactly equals the adjusted bounds. */
1987 #ifdef REAL_ARITHMETIC
1988 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1989 if (!no_upper_bound
)
1990 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1993 if (!no_upper_bound
)
1996 /* If X is a NaN, use zero instead and show we have an overflow.
1997 Otherwise, range check. */
1998 if (REAL_VALUE_ISNAN (x
))
1999 overflow
= 1, x
= dconst0
;
2000 else if (! (REAL_VALUES_LESS (l
, x
)
2002 && REAL_VALUES_LESS (x
, u
)))
2005 #ifndef REAL_ARITHMETIC
2007 HOST_WIDE_INT low
, high
;
2008 HOST_WIDE_INT half_word
2009 = (HOST_WIDE_INT
) 1 << (HOST_BITS_PER_WIDE_INT
/ 2);
2014 high
= (HOST_WIDE_INT
) (x
/ half_word
/ half_word
);
2015 x
-= (REAL_VALUE_TYPE
) high
* half_word
* half_word
;
2016 if (x
>= (REAL_VALUE_TYPE
) half_word
* half_word
/ 2)
2018 low
= x
- (REAL_VALUE_TYPE
) half_word
* half_word
/ 2;
2019 low
|= (HOST_WIDE_INT
) -1 << (HOST_BITS_PER_WIDE_INT
- 1);
2022 low
= (HOST_WIDE_INT
) x
;
2023 if (TREE_REAL_CST (arg1
) < 0)
2024 neg_double (low
, high
, &low
, &high
);
2025 t
= build_int_2 (low
, high
);
2029 HOST_WIDE_INT low
, high
;
2030 REAL_VALUE_TO_INT (&low
, &high
, x
);
2031 t
= build_int_2 (low
, high
);
2034 TREE_TYPE (t
) = type
;
2036 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2037 TREE_CONSTANT_OVERFLOW (t
)
2038 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2040 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2041 TREE_TYPE (t
) = type
;
2043 else if (TREE_CODE (type
) == REAL_TYPE
)
2045 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
2046 if (TREE_CODE (arg1
) == INTEGER_CST
)
2047 return build_real_from_int_cst (type
, arg1
);
2048 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
2049 if (TREE_CODE (arg1
) == REAL_CST
)
2051 struct fc_args args
;
2053 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
2056 TREE_TYPE (arg1
) = type
;
2060 /* Setup input for fold_convert_1() */
2064 if (do_float_handler (fold_convert_1
, (PTR
) &args
))
2066 /* Receive output from fold_convert_1() */
2071 /* We got an exception from fold_convert_1() */
2073 t
= copy_node (arg1
);
2077 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
2078 TREE_CONSTANT_OVERFLOW (t
)
2079 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
2083 TREE_CONSTANT (t
) = 1;
2087 /* Return an expr equal to X but certainly not valid as an lvalue. */
2095 /* These things are certainly not lvalues. */
2096 if (TREE_CODE (x
) == NON_LVALUE_EXPR
2097 || TREE_CODE (x
) == INTEGER_CST
2098 || TREE_CODE (x
) == REAL_CST
2099 || TREE_CODE (x
) == STRING_CST
2100 || TREE_CODE (x
) == ADDR_EXPR
)
2103 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
2104 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
2108 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2109 Zero means allow extended lvalues. */
2111 int pedantic_lvalues
;
2113 /* When pedantic, return an expr equal to X but certainly not valid as a
2114 pedantic lvalue. Otherwise, return X. */
2117 pedantic_non_lvalue (x
)
2120 if (pedantic_lvalues
)
2121 return non_lvalue (x
);
2126 /* Given a tree comparison code, return the code that is the logical inverse
2127 of the given code. It is not safe to do this for floating-point
2128 comparisons, except for NE_EXPR and EQ_EXPR. */
2130 static enum tree_code
2131 invert_tree_comparison (code
)
2132 enum tree_code code
;
2153 /* Similar, but return the comparison that results if the operands are
2154 swapped. This is safe for floating-point. */
2156 static enum tree_code
2157 swap_tree_comparison (code
)
2158 enum tree_code code
;
2178 /* Return nonzero if CODE is a tree code that represents a truth value. */
2181 truth_value_p (code
)
2182 enum tree_code code
;
2184 return (TREE_CODE_CLASS (code
) == '<'
2185 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
2186 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
2187 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
2190 /* Return nonzero if two operands are necessarily equal.
2191 If ONLY_CONST is non-zero, only return non-zero for constants.
2192 This function tests whether the operands are indistinguishable;
2193 it does not test whether they are equal using C's == operation.
2194 The distinction is important for IEEE floating point, because
2195 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
2196 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
2199 operand_equal_p (arg0
, arg1
, only_const
)
2203 /* If both types don't have the same signedness, then we can't consider
2204 them equal. We must check this before the STRIP_NOPS calls
2205 because they may change the signedness of the arguments. */
2206 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
2212 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2213 /* This is needed for conversions and for COMPONENT_REF.
2214 Might as well play it safe and always test this. */
2215 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
2216 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
2217 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
2220 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2221 We don't care about side effects in that case because the SAVE_EXPR
2222 takes care of that for us. In all other cases, two expressions are
2223 equal if they have no side effects. If we have two identical
2224 expressions with side effects that should be treated the same due
2225 to the only side effects being identical SAVE_EXPR's, that will
2226 be detected in the recursive calls below. */
2227 if (arg0
== arg1
&& ! only_const
2228 && (TREE_CODE (arg0
) == SAVE_EXPR
2229 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
2232 /* Next handle constant cases, those for which we can return 1 even
2233 if ONLY_CONST is set. */
2234 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
2235 switch (TREE_CODE (arg0
))
2238 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2239 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2240 && TREE_INT_CST_LOW (arg0
) == TREE_INT_CST_LOW (arg1
)
2241 && TREE_INT_CST_HIGH (arg0
) == TREE_INT_CST_HIGH (arg1
));
2244 return (! TREE_CONSTANT_OVERFLOW (arg0
)
2245 && ! TREE_CONSTANT_OVERFLOW (arg1
)
2246 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
2247 TREE_REAL_CST (arg1
)));
2250 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
2252 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
2256 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
2257 && ! strncmp (TREE_STRING_POINTER (arg0
),
2258 TREE_STRING_POINTER (arg1
),
2259 TREE_STRING_LENGTH (arg0
)));
2262 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
2271 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
2274 /* Two conversions are equal only if signedness and modes match. */
2275 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
2276 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
2277 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
2280 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2281 TREE_OPERAND (arg1
, 0), 0);
2285 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
2286 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
2290 /* For commutative ops, allow the other order. */
2291 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
2292 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
2293 || TREE_CODE (arg0
) == BIT_IOR_EXPR
2294 || TREE_CODE (arg0
) == BIT_XOR_EXPR
2295 || TREE_CODE (arg0
) == BIT_AND_EXPR
2296 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
2297 && operand_equal_p (TREE_OPERAND (arg0
, 0),
2298 TREE_OPERAND (arg1
, 1), 0)
2299 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2300 TREE_OPERAND (arg1
, 0), 0));
2303 /* If either of the pointer (or reference) expressions we are dereferencing
2304 contain a side effect, these cannot be equal. */
2305 if (TREE_SIDE_EFFECTS (arg0
)
2306 || TREE_SIDE_EFFECTS (arg1
))
2309 switch (TREE_CODE (arg0
))
2312 return operand_equal_p (TREE_OPERAND (arg0
, 0),
2313 TREE_OPERAND (arg1
, 0), 0);
2317 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2318 TREE_OPERAND (arg1
, 0), 0)
2319 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2320 TREE_OPERAND (arg1
, 1), 0));
2323 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
2324 TREE_OPERAND (arg1
, 0), 0)
2325 && operand_equal_p (TREE_OPERAND (arg0
, 1),
2326 TREE_OPERAND (arg1
, 1), 0)
2327 && operand_equal_p (TREE_OPERAND (arg0
, 2),
2328 TREE_OPERAND (arg1
, 2), 0));
2334 if (TREE_CODE (arg0
) == RTL_EXPR
)
2335 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2343 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2344 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2346 When in doubt, return 0. */
2349 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2353 int unsignedp1
, unsignedpo
;
2354 tree primarg0
, primarg1
, primother
;
2355 unsigned correct_width
;
2357 if (operand_equal_p (arg0
, arg1
, 0))
2360 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2361 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2364 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2365 and see if the inner values are the same. This removes any
2366 signedness comparison, which doesn't matter here. */
2367 primarg0
= arg0
, primarg1
= arg1
;
2368 STRIP_NOPS (primarg0
); STRIP_NOPS (primarg1
);
2369 if (operand_equal_p (primarg0
, primarg1
, 0))
2372 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2373 actual comparison operand, ARG0.
2375 First throw away any conversions to wider types
2376 already present in the operands. */
2378 primarg1
= get_narrower (arg1
, &unsignedp1
);
2379 primother
= get_narrower (other
, &unsignedpo
);
2381 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2382 if (unsignedp1
== unsignedpo
2383 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2384 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2386 tree type
= TREE_TYPE (arg0
);
2388 /* Make sure shorter operand is extended the right way
2389 to match the longer operand. */
2390 primarg1
= convert (signed_or_unsigned_type (unsignedp1
,
2391 TREE_TYPE (primarg1
)),
2394 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2401 /* See if ARG is an expression that is either a comparison or is performing
2402 arithmetic on comparisons. The comparisons must only be comparing
2403 two different values, which will be stored in *CVAL1 and *CVAL2; if
2404 they are non-zero it means that some operands have already been found.
2405 No variables may be used anywhere else in the expression except in the
2406 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2407 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2409 If this is true, return 1. Otherwise, return zero. */
2412 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2414 tree
*cval1
, *cval2
;
2417 enum tree_code code
= TREE_CODE (arg
);
2418 char class = TREE_CODE_CLASS (code
);
2420 /* We can handle some of the 'e' cases here. */
2421 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2423 else if (class == 'e'
2424 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2425 || code
== COMPOUND_EXPR
))
2428 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2429 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2431 /* If we've already found a CVAL1 or CVAL2, this expression is
2432 two complex to handle. */
2433 if (*cval1
|| *cval2
)
2443 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2446 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2447 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2448 cval1
, cval2
, save_p
));
2454 if (code
== COND_EXPR
)
2455 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2456 cval1
, cval2
, save_p
)
2457 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2458 cval1
, cval2
, save_p
)
2459 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2460 cval1
, cval2
, save_p
));
2464 /* First see if we can handle the first operand, then the second. For
2465 the second operand, we know *CVAL1 can't be zero. It must be that
2466 one side of the comparison is each of the values; test for the
2467 case where this isn't true by failing if the two operands
2470 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2471 TREE_OPERAND (arg
, 1), 0))
2475 *cval1
= TREE_OPERAND (arg
, 0);
2476 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2478 else if (*cval2
== 0)
2479 *cval2
= TREE_OPERAND (arg
, 0);
2480 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2485 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2487 else if (*cval2
== 0)
2488 *cval2
= TREE_OPERAND (arg
, 1);
2489 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2501 /* ARG is a tree that is known to contain just arithmetic operations and
2502 comparisons. Evaluate the operations in the tree substituting NEW0 for
2503 any occurrence of OLD0 as an operand of a comparison and likewise for
2507 eval_subst (arg
, old0
, new0
, old1
, new1
)
2509 tree old0
, new0
, old1
, new1
;
2511 tree type
= TREE_TYPE (arg
);
2512 enum tree_code code
= TREE_CODE (arg
);
2513 char class = TREE_CODE_CLASS (code
);
2515 /* We can handle some of the 'e' cases here. */
2516 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2518 else if (class == 'e'
2519 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2525 return fold (build1 (code
, type
,
2526 eval_subst (TREE_OPERAND (arg
, 0),
2527 old0
, new0
, old1
, new1
)));
2530 return fold (build (code
, type
,
2531 eval_subst (TREE_OPERAND (arg
, 0),
2532 old0
, new0
, old1
, new1
),
2533 eval_subst (TREE_OPERAND (arg
, 1),
2534 old0
, new0
, old1
, new1
)));
2540 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2543 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2546 return fold (build (code
, type
,
2547 eval_subst (TREE_OPERAND (arg
, 0),
2548 old0
, new0
, old1
, new1
),
2549 eval_subst (TREE_OPERAND (arg
, 1),
2550 old0
, new0
, old1
, new1
),
2551 eval_subst (TREE_OPERAND (arg
, 2),
2552 old0
, new0
, old1
, new1
)));
2556 /* fall through - ??? */
2560 tree arg0
= TREE_OPERAND (arg
, 0);
2561 tree arg1
= TREE_OPERAND (arg
, 1);
2563 /* We need to check both for exact equality and tree equality. The
2564 former will be true if the operand has a side-effect. In that
2565 case, we know the operand occurred exactly once. */
2567 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2569 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2572 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2574 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2577 return fold (build (code
, type
, arg0
, arg1
));
2585 /* Return a tree for the case when the result of an expression is RESULT
2586 converted to TYPE and OMITTED was previously an operand of the expression
2587 but is now not needed (e.g., we folded OMITTED * 0).
2589 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2590 the conversion of RESULT to TYPE. */
2593 omit_one_operand (type
, result
, omitted
)
2594 tree type
, result
, omitted
;
2596 tree t
= convert (type
, result
);
2598 if (TREE_SIDE_EFFECTS (omitted
))
2599 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2601 return non_lvalue (t
);
2604 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2607 pedantic_omit_one_operand (type
, result
, omitted
)
2608 tree type
, result
, omitted
;
2610 tree t
= convert (type
, result
);
2612 if (TREE_SIDE_EFFECTS (omitted
))
2613 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2615 return pedantic_non_lvalue (t
);
2620 /* Return a simplified tree node for the truth-negation of ARG. This
2621 never alters ARG itself. We assume that ARG is an operation that
2622 returns a truth value (0 or 1). */
2625 invert_truthvalue (arg
)
2628 tree type
= TREE_TYPE (arg
);
2629 enum tree_code code
= TREE_CODE (arg
);
2631 if (code
== ERROR_MARK
)
2634 /* If this is a comparison, we can simply invert it, except for
2635 floating-point non-equality comparisons, in which case we just
2636 enclose a TRUTH_NOT_EXPR around what we have. */
2638 if (TREE_CODE_CLASS (code
) == '<')
2640 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2641 && !flag_fast_math
&& code
!= NE_EXPR
&& code
!= EQ_EXPR
)
2642 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2644 return build (invert_tree_comparison (code
), type
,
2645 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2651 return convert (type
, build_int_2 (TREE_INT_CST_LOW (arg
) == 0
2652 && TREE_INT_CST_HIGH (arg
) == 0, 0));
2654 case TRUTH_AND_EXPR
:
2655 return build (TRUTH_OR_EXPR
, type
,
2656 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2657 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2660 return build (TRUTH_AND_EXPR
, type
,
2661 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2662 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2664 case TRUTH_XOR_EXPR
:
2665 /* Here we can invert either operand. We invert the first operand
2666 unless the second operand is a TRUTH_NOT_EXPR in which case our
2667 result is the XOR of the first operand with the inside of the
2668 negation of the second operand. */
2670 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2671 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2672 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2674 return build (TRUTH_XOR_EXPR
, type
,
2675 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2676 TREE_OPERAND (arg
, 1));
2678 case TRUTH_ANDIF_EXPR
:
2679 return build (TRUTH_ORIF_EXPR
, type
,
2680 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2681 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2683 case TRUTH_ORIF_EXPR
:
2684 return build (TRUTH_ANDIF_EXPR
, type
,
2685 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2686 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2688 case TRUTH_NOT_EXPR
:
2689 return TREE_OPERAND (arg
, 0);
2692 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2693 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2694 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2697 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2698 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2700 case WITH_RECORD_EXPR
:
2701 return build (WITH_RECORD_EXPR
, type
,
2702 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2703 TREE_OPERAND (arg
, 1));
2705 case NON_LVALUE_EXPR
:
2706 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2711 return build1 (TREE_CODE (arg
), type
,
2712 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2715 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2717 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2720 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2722 case CLEANUP_POINT_EXPR
:
2723 return build1 (CLEANUP_POINT_EXPR
, type
,
2724 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2729 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2731 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2734 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2735 operands are another bit-wise operation with a common input. If so,
2736 distribute the bit operations to save an operation and possibly two if
2737 constants are involved. For example, convert
2738 (A | B) & (A | C) into A | (B & C)
2739 Further simplification will occur if B and C are constants.
2741 If this optimization cannot be done, 0 will be returned. */
2744 distribute_bit_expr (code
, type
, arg0
, arg1
)
2745 enum tree_code code
;
2752 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2753 || TREE_CODE (arg0
) == code
2754 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2755 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2758 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2760 common
= TREE_OPERAND (arg0
, 0);
2761 left
= TREE_OPERAND (arg0
, 1);
2762 right
= TREE_OPERAND (arg1
, 1);
2764 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2766 common
= TREE_OPERAND (arg0
, 0);
2767 left
= TREE_OPERAND (arg0
, 1);
2768 right
= TREE_OPERAND (arg1
, 0);
2770 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2772 common
= TREE_OPERAND (arg0
, 1);
2773 left
= TREE_OPERAND (arg0
, 0);
2774 right
= TREE_OPERAND (arg1
, 1);
2776 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2778 common
= TREE_OPERAND (arg0
, 1);
2779 left
= TREE_OPERAND (arg0
, 0);
2780 right
= TREE_OPERAND (arg1
, 0);
2785 return fold (build (TREE_CODE (arg0
), type
, common
,
2786 fold (build (code
, type
, left
, right
))));
2789 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2790 starting at BITPOS. The field is unsigned if UNSIGNEDP is non-zero. */
2793 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2796 int bitsize
, bitpos
;
2799 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2800 size_int (bitsize
), bitsize_int (bitpos
, 0L));
2802 TREE_UNSIGNED (result
) = unsignedp
;
2807 /* Optimize a bit-field compare.
2809 There are two cases: First is a compare against a constant and the
2810 second is a comparison of two items where the fields are at the same
2811 bit position relative to the start of a chunk (byte, halfword, word)
2812 large enough to contain it. In these cases we can avoid the shift
2813 implicit in bitfield extractions.
2815 For constants, we emit a compare of the shifted constant with the
2816 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2817 compared. For two fields at the same position, we do the ANDs with the
2818 similar mask and compare the result of the ANDs.
2820 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2821 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2822 are the left and right operands of the comparison, respectively.
2824 If the optimization described above can be done, we return the resulting
2825 tree. Otherwise we return zero. */
2828 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
2829 enum tree_code code
;
2833 int lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2834 tree type
= TREE_TYPE (lhs
);
2835 tree signed_type
, unsigned_type
;
2836 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2837 enum machine_mode lmode
, rmode
, nmode
;
2838 int lunsignedp
, runsignedp
;
2839 int lvolatilep
= 0, rvolatilep
= 0;
2841 tree linner
, rinner
= NULL_TREE
;
2845 /* Get all the information about the extractions being done. If the bit size
2846 if the same as the size of the underlying object, we aren't doing an
2847 extraction at all and so can do nothing. We also don't want to
2848 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2849 then will no longer be able to replace it. */
2850 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2851 &lunsignedp
, &lvolatilep
, &alignment
);
2852 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2853 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2858 /* If this is not a constant, we can only do something if bit positions,
2859 sizes, and signedness are the same. */
2860 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2861 &runsignedp
, &rvolatilep
, &alignment
);
2863 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2864 || lunsignedp
!= runsignedp
|| offset
!= 0
2865 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2869 /* See if we can find a mode to refer to this field. We should be able to,
2870 but fail if we can't. */
2871 nmode
= get_best_mode (lbitsize
, lbitpos
,
2872 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2873 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2874 TYPE_ALIGN (TREE_TYPE (rinner
))),
2875 word_mode
, lvolatilep
|| rvolatilep
);
2876 if (nmode
== VOIDmode
)
2879 /* Set signed and unsigned types of the precision of this mode for the
2881 signed_type
= type_for_mode (nmode
, 0);
2882 unsigned_type
= type_for_mode (nmode
, 1);
2884 /* Compute the bit position and size for the new reference and our offset
2885 within it. If the new reference is the same size as the original, we
2886 won't optimize anything, so return zero. */
2887 nbitsize
= GET_MODE_BITSIZE (nmode
);
2888 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2890 if (nbitsize
== lbitsize
)
2893 if (BYTES_BIG_ENDIAN
)
2894 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2896 /* Make the mask to be used against the extracted field. */
2897 mask
= build_int_2 (~0, ~0);
2898 TREE_TYPE (mask
) = unsigned_type
;
2899 force_fit_type (mask
, 0);
2900 mask
= convert (unsigned_type
, mask
);
2901 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2902 mask
= const_binop (RSHIFT_EXPR
, mask
,
2903 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2906 /* If not comparing with constant, just rework the comparison
2908 return build (code
, compare_type
,
2909 build (BIT_AND_EXPR
, unsigned_type
,
2910 make_bit_field_ref (linner
, unsigned_type
,
2911 nbitsize
, nbitpos
, 1),
2913 build (BIT_AND_EXPR
, unsigned_type
,
2914 make_bit_field_ref (rinner
, unsigned_type
,
2915 nbitsize
, nbitpos
, 1),
2918 /* Otherwise, we are handling the constant case. See if the constant is too
2919 big for the field. Warn and return a tree of for 0 (false) if so. We do
2920 this not only for its own sake, but to avoid having to test for this
2921 error case below. If we didn't, we might generate wrong code.
2923 For unsigned fields, the constant shifted right by the field length should
2924 be all zero. For signed fields, the high-order bits should agree with
2929 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2930 convert (unsigned_type
, rhs
),
2931 size_int (lbitsize
), 0)))
2933 warning ("comparison is always %d due to width of bitfield",
2935 return convert (compare_type
,
2937 ? integer_one_node
: integer_zero_node
));
2942 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2943 size_int (lbitsize
- 1), 0);
2944 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2946 warning ("comparison is always %d due to width of bitfield",
2948 return convert (compare_type
,
2950 ? integer_one_node
: integer_zero_node
));
2954 /* Single-bit compares should always be against zero. */
2955 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2957 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2958 rhs
= convert (type
, integer_zero_node
);
2961 /* Make a new bitfield reference, shift the constant over the
2962 appropriate number of bits and mask it with the computed mask
2963 (in case this was a signed field). If we changed it, make a new one. */
2964 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2967 TREE_SIDE_EFFECTS (lhs
) = 1;
2968 TREE_THIS_VOLATILE (lhs
) = 1;
2971 rhs
= fold (const_binop (BIT_AND_EXPR
,
2972 const_binop (LSHIFT_EXPR
,
2973 convert (unsigned_type
, rhs
),
2974 size_int (lbitpos
), 0),
2977 return build (code
, compare_type
,
2978 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2982 /* Subroutine for fold_truthop: decode a field reference.
2984 If EXP is a comparison reference, we return the innermost reference.
2986 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2987 set to the starting bit number.
2989 If the innermost field can be completely contained in a mode-sized
2990 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2992 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2993 otherwise it is not changed.
2995 *PUNSIGNEDP is set to the signedness of the field.
2997 *PMASK is set to the mask used. This is either contained in a
2998 BIT_AND_EXPR or derived from the width of the field.
3000 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
3002 Return 0 if this is not a component reference or is one that we can't
3003 do anything with. */
3006 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
3007 pvolatilep
, pmask
, pand_mask
)
3009 int *pbitsize
, *pbitpos
;
3010 enum machine_mode
*pmode
;
3011 int *punsignedp
, *pvolatilep
;
3016 tree mask
, inner
, offset
;
3021 /* All the optimizations using this function assume integer fields.
3022 There are problems with FP fields since the type_for_size call
3023 below can fail for, e.g., XFmode. */
3024 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
3029 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
3031 and_mask
= TREE_OPERAND (exp
, 1);
3032 exp
= TREE_OPERAND (exp
, 0);
3033 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
3034 if (TREE_CODE (and_mask
) != INTEGER_CST
)
3039 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
3040 punsignedp
, pvolatilep
, &alignment
);
3041 if ((inner
== exp
&& and_mask
== 0)
3042 || *pbitsize
< 0 || offset
!= 0
3043 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
3046 /* Compute the mask to access the bitfield. */
3047 unsigned_type
= type_for_size (*pbitsize
, 1);
3048 precision
= TYPE_PRECISION (unsigned_type
);
3050 mask
= build_int_2 (~0, ~0);
3051 TREE_TYPE (mask
) = unsigned_type
;
3052 force_fit_type (mask
, 0);
3053 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3054 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
3056 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3058 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
3059 convert (unsigned_type
, and_mask
), mask
));
3062 *pand_mask
= and_mask
;
3066 /* Return non-zero if MASK represents a mask of SIZE ones in the low-order
3070 all_ones_mask_p (mask
, size
)
3074 tree type
= TREE_TYPE (mask
);
3075 int precision
= TYPE_PRECISION (type
);
3078 tmask
= build_int_2 (~0, ~0);
3079 TREE_TYPE (tmask
) = signed_type (type
);
3080 force_fit_type (tmask
, 0);
3082 tree_int_cst_equal (mask
,
3083 const_binop (RSHIFT_EXPR
,
3084 const_binop (LSHIFT_EXPR
, tmask
,
3085 size_int (precision
- size
),
3087 size_int (precision
- size
), 0));
3090 /* Subroutine for fold_truthop: determine if an operand is simple enough
3091 to be evaluated unconditionally. */
3094 simple_operand_p (exp
)
3097 /* Strip any conversions that don't change the machine mode. */
3098 while ((TREE_CODE (exp
) == NOP_EXPR
3099 || TREE_CODE (exp
) == CONVERT_EXPR
)
3100 && (TYPE_MODE (TREE_TYPE (exp
))
3101 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
3102 exp
= TREE_OPERAND (exp
, 0);
3104 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
3105 || (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'd'
3106 && ! TREE_ADDRESSABLE (exp
)
3107 && ! TREE_THIS_VOLATILE (exp
)
3108 && ! DECL_NONLOCAL (exp
)
3109 /* Don't regard global variables as simple. They may be
3110 allocated in ways unknown to the compiler (shared memory,
3111 #pragma weak, etc). */
3112 && ! TREE_PUBLIC (exp
)
3113 && ! DECL_EXTERNAL (exp
)
3114 /* Loading a static variable is unduly expensive, but global
3115 registers aren't expensive. */
3116 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
3119 /* The following functions are subroutines to fold_range_test and allow it to
3120 try to change a logical combination of comparisons into a range test.
3123 X == 2 && X == 3 && X == 4 && X == 5
3127 (unsigned) (X - 2) <= 3
3129 We describe each set of comparisons as being either inside or outside
3130 a range, using a variable named like IN_P, and then describe the
3131 range with a lower and upper bound. If one of the bounds is omitted,
3132 it represents either the highest or lowest value of the type.
3134 In the comments below, we represent a range by two numbers in brackets
3135 preceded by a "+" to designate being inside that range, or a "-" to
3136 designate being outside that range, so the condition can be inverted by
3137 flipping the prefix. An omitted bound is represented by a "-". For
3138 example, "- [-, 10]" means being outside the range starting at the lowest
3139 possible value and ending at 10, in other words, being greater than 10.
3140 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3143 We set up things so that the missing bounds are handled in a consistent
3144 manner so neither a missing bound nor "true" and "false" need to be
3145 handled using a special case. */
3147 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3148 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3149 and UPPER1_P are nonzero if the respective argument is an upper bound
3150 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3151 must be specified for a comparison. ARG1 will be converted to ARG0's
3152 type if both are specified. */
3155 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
3156 enum tree_code code
;
3159 int upper0_p
, upper1_p
;
3165 /* If neither arg represents infinity, do the normal operation.
3166 Else, if not a comparison, return infinity. Else handle the special
3167 comparison rules. Note that most of the cases below won't occur, but
3168 are handled for consistency. */
3170 if (arg0
!= 0 && arg1
!= 0)
3172 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
3173 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
3175 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
3178 if (TREE_CODE_CLASS (code
) != '<')
3181 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
3182 for neither. In real maths, we cannot assume open ended ranges are
3183 the same. But, this is computer arithmetic, where numbers are finite.
3184 We can therefore make the transformation of any unbounded range with
3185 the value Z, Z being greater than any representable number. This permits
3186 us to treat unbounded ranges as equal. */
3187 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
3188 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
3192 result
= sgn0
== sgn1
;
3195 result
= sgn0
!= sgn1
;
3198 result
= sgn0
< sgn1
;
3201 result
= sgn0
<= sgn1
;
3204 result
= sgn0
> sgn1
;
3207 result
= sgn0
>= sgn1
;
3213 return convert (type
, result
? integer_one_node
: integer_zero_node
);
3216 /* Given EXP, a logical expression, set the range it is testing into
3217 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
3218 actually being tested. *PLOW and *PHIGH will have be made the same type
3219 as the returned expression. If EXP is not a comparison, we will most
3220 likely not be returning a useful value and range. */
3223 make_range (exp
, pin_p
, plow
, phigh
)
3228 enum tree_code code
;
3229 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
3230 tree orig_type
= NULL_TREE
;
3232 tree low
, high
, n_low
, n_high
;
3234 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3235 and see if we can refine the range. Some of the cases below may not
3236 happen, but it doesn't seem worth worrying about this. We "continue"
3237 the outer loop when we've changed something; otherwise we "break"
3238 the switch, which will "break" the while. */
3240 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
3244 code
= TREE_CODE (exp
);
3246 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
3248 arg0
= TREE_OPERAND (exp
, 0);
3249 if (TREE_CODE_CLASS (code
) == '<'
3250 || TREE_CODE_CLASS (code
) == '1'
3251 || TREE_CODE_CLASS (code
) == '2')
3252 type
= TREE_TYPE (arg0
);
3253 if (TREE_CODE_CLASS (code
) == '2'
3254 || TREE_CODE_CLASS (code
) == '<'
3255 || (TREE_CODE_CLASS (code
) == 'e'
3256 && tree_code_length
[(int) code
] > 1))
3257 arg1
= TREE_OPERAND (exp
, 1);
3260 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3261 lose a cast by accident. */
3262 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
3267 case TRUTH_NOT_EXPR
:
3268 in_p
= ! in_p
, exp
= arg0
;
3271 case EQ_EXPR
: case NE_EXPR
:
3272 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3273 /* We can only do something if the range is testing for zero
3274 and if the second operand is an integer constant. Note that
3275 saying something is "in" the range we make is done by
3276 complementing IN_P since it will set in the initial case of
3277 being not equal to zero; "out" is leaving it alone. */
3278 if (low
== 0 || high
== 0
3279 || ! integer_zerop (low
) || ! integer_zerop (high
)
3280 || TREE_CODE (arg1
) != INTEGER_CST
)
3285 case NE_EXPR
: /* - [c, c] */
3288 case EQ_EXPR
: /* + [c, c] */
3289 in_p
= ! in_p
, low
= high
= arg1
;
3291 case GT_EXPR
: /* - [-, c] */
3292 low
= 0, high
= arg1
;
3294 case GE_EXPR
: /* + [c, -] */
3295 in_p
= ! in_p
, low
= arg1
, high
= 0;
3297 case LT_EXPR
: /* - [c, -] */
3298 low
= arg1
, high
= 0;
3300 case LE_EXPR
: /* + [-, c] */
3301 in_p
= ! in_p
, low
= 0, high
= arg1
;
3309 /* If this is an unsigned comparison, we also know that EXP is
3310 greater than or equal to zero. We base the range tests we make
3311 on that fact, so we record it here so we can parse existing
3313 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3315 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3316 1, convert (type
, integer_zero_node
),
3320 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3322 /* If the high bound is missing, reverse the range so it
3323 goes from zero to the low bound minus 1. */
3327 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3328 integer_one_node
, 0);
3329 low
= convert (type
, integer_zero_node
);
3335 /* (-x) IN [a,b] -> x in [-b, -a] */
3336 n_low
= range_binop (MINUS_EXPR
, type
,
3337 convert (type
, integer_zero_node
), 0, high
, 1);
3338 n_high
= range_binop (MINUS_EXPR
, type
,
3339 convert (type
, integer_zero_node
), 0, low
, 0);
3340 low
= n_low
, high
= n_high
;
3346 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3347 convert (type
, integer_one_node
));
3350 case PLUS_EXPR
: case MINUS_EXPR
:
3351 if (TREE_CODE (arg1
) != INTEGER_CST
)
3354 /* If EXP is signed, any overflow in the computation is undefined,
3355 so we don't worry about it so long as our computations on
3356 the bounds don't overflow. For unsigned, overflow is defined
3357 and this is exactly the right thing. */
3358 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3359 type
, low
, 0, arg1
, 0);
3360 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3361 type
, high
, 1, arg1
, 0);
3362 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3363 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3366 /* Check for an unsigned range which has wrapped around the maximum
3367 value thus making n_high < n_low, and normalize it. */
3368 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3370 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3371 integer_one_node
, 0);
3372 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3373 integer_one_node
, 0);
3377 low
= n_low
, high
= n_high
;
3382 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3383 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3386 if (! INTEGRAL_TYPE_P (type
)
3387 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3388 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3391 n_low
= low
, n_high
= high
;
3394 n_low
= convert (type
, n_low
);
3397 n_high
= convert (type
, n_high
);
3399 /* If we're converting from an unsigned to a signed type,
3400 we will be doing the comparison as unsigned. The tests above
3401 have already verified that LOW and HIGH are both positive.
3403 So we have to make sure that the original unsigned value will
3404 be interpreted as positive. */
3405 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3407 tree equiv_type
= type_for_mode (TYPE_MODE (type
), 1);
3410 /* A range without an upper bound is, naturally, unbounded.
3411 Since convert would have cropped a very large value, use
3412 the max value for the destination type. */
3414 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3415 : TYPE_MAX_VALUE (type
);
3417 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3418 convert (type
, high_positive
),
3419 convert (type
, integer_one_node
)));
3421 /* If the low bound is specified, "and" the range with the
3422 range for which the original unsigned value will be
3426 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3428 1, convert (type
, integer_zero_node
),
3432 in_p
= (n_in_p
== in_p
);
3436 /* Otherwise, "or" the range with the range of the input
3437 that will be interpreted as negative. */
3438 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3440 1, convert (type
, integer_zero_node
),
3444 in_p
= (in_p
!= n_in_p
);
3449 low
= n_low
, high
= n_high
;
3459 /* If EXP is a constant, we can evaluate whether this is true or false. */
3460 if (TREE_CODE (exp
) == INTEGER_CST
)
3462 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3464 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3470 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3474 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3475 type, TYPE, return an expression to test if EXP is in (or out of, depending
3476 on IN_P) the range. */
3479 build_range_check (type
, exp
, in_p
, low
, high
)
3485 tree etype
= TREE_TYPE (exp
);
3489 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3490 return invert_truthvalue (value
);
3492 else if (low
== 0 && high
== 0)
3493 return convert (type
, integer_one_node
);
3496 return fold (build (LE_EXPR
, type
, exp
, high
));
3499 return fold (build (GE_EXPR
, type
, exp
, low
));
3501 else if (operand_equal_p (low
, high
, 0))
3502 return fold (build (EQ_EXPR
, type
, exp
, low
));
3504 else if (TREE_UNSIGNED (etype
) && integer_zerop (low
))
3505 return build_range_check (type
, exp
, 1, 0, high
);
3507 else if (integer_zerop (low
))
3509 utype
= unsigned_type (etype
);
3510 return build_range_check (type
, convert (utype
, exp
), 1, 0,
3511 convert (utype
, high
));
3514 else if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3515 && ! TREE_OVERFLOW (value
))
3516 return build_range_check (type
,
3517 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3518 1, convert (etype
, integer_zero_node
), value
);
3523 /* Given two ranges, see if we can merge them into one. Return 1 if we
3524 can, 0 if we can't. Set the output range into the specified parameters. */
3527 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3531 tree low0
, high0
, low1
, high1
;
3539 int lowequal
= ((low0
== 0 && low1
== 0)
3540 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3541 low0
, 0, low1
, 0)));
3542 int highequal
= ((high0
== 0 && high1
== 0)
3543 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3544 high0
, 1, high1
, 1)));
3546 /* Make range 0 be the range that starts first, or ends last if they
3547 start at the same value. Swap them if it isn't. */
3548 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3551 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3552 high1
, 1, high0
, 1))))
3554 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3555 tem
= low0
, low0
= low1
, low1
= tem
;
3556 tem
= high0
, high0
= high1
, high1
= tem
;
3559 /* Now flag two cases, whether the ranges are disjoint or whether the
3560 second range is totally subsumed in the first. Note that the tests
3561 below are simplified by the ones above. */
3562 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3563 high0
, 1, low1
, 0));
3564 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3565 high1
, 1, high0
, 1));
3567 /* We now have four cases, depending on whether we are including or
3568 excluding the two ranges. */
3571 /* If they don't overlap, the result is false. If the second range
3572 is a subset it is the result. Otherwise, the range is from the start
3573 of the second to the end of the first. */
3575 in_p
= 0, low
= high
= 0;
3577 in_p
= 1, low
= low1
, high
= high1
;
3579 in_p
= 1, low
= low1
, high
= high0
;
3582 else if (in0_p
&& ! in1_p
)
3584 /* If they don't overlap, the result is the first range. If they are
3585 equal, the result is false. If the second range is a subset of the
3586 first, and the ranges begin at the same place, we go from just after
3587 the end of the first range to the end of the second. If the second
3588 range is not a subset of the first, or if it is a subset and both
3589 ranges end at the same place, the range starts at the start of the
3590 first range and ends just before the second range.
3591 Otherwise, we can't describe this as a single range. */
3593 in_p
= 1, low
= low0
, high
= high0
;
3594 else if (lowequal
&& highequal
)
3595 in_p
= 0, low
= high
= 0;
3596 else if (subset
&& lowequal
)
3598 in_p
= 1, high
= high0
;
3599 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3600 integer_one_node
, 0);
3602 else if (! subset
|| highequal
)
3604 in_p
= 1, low
= low0
;
3605 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3606 integer_one_node
, 0);
3612 else if (! in0_p
&& in1_p
)
3614 /* If they don't overlap, the result is the second range. If the second
3615 is a subset of the first, the result is false. Otherwise,
3616 the range starts just after the first range and ends at the
3617 end of the second. */
3619 in_p
= 1, low
= low1
, high
= high1
;
3620 else if (subset
|| highequal
)
3621 in_p
= 0, low
= high
= 0;
3624 in_p
= 1, high
= high1
;
3625 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3626 integer_one_node
, 0);
3632 /* The case where we are excluding both ranges. Here the complex case
3633 is if they don't overlap. In that case, the only time we have a
3634 range is if they are adjacent. If the second is a subset of the
3635 first, the result is the first. Otherwise, the range to exclude
3636 starts at the beginning of the first range and ends at the end of the
3640 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3641 range_binop (PLUS_EXPR
, NULL_TREE
,
3643 integer_one_node
, 1),
3645 in_p
= 0, low
= low0
, high
= high1
;
3650 in_p
= 0, low
= low0
, high
= high0
;
3652 in_p
= 0, low
= low0
, high
= high1
;
3655 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3659 /* EXP is some logical combination of boolean tests. See if we can
3660 merge it into some range test. Return the new tree if so. */
3663 fold_range_test (exp
)
3666 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3667 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3668 int in0_p
, in1_p
, in_p
;
3669 tree low0
, low1
, low
, high0
, high1
, high
;
3670 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3671 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3674 /* If this is an OR operation, invert both sides; we will invert
3675 again at the end. */
3677 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3679 /* If both expressions are the same, if we can merge the ranges, and we
3680 can build the range test, return it or it inverted. If one of the
3681 ranges is always true or always false, consider it to be the same
3682 expression as the other. */
3683 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3684 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3686 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3688 : rhs
!= 0 ? rhs
: integer_zero_node
,
3690 return or_op
? invert_truthvalue (tem
) : tem
;
3692 /* On machines where the branch cost is expensive, if this is a
3693 short-circuited branch and the underlying object on both sides
3694 is the same, make a non-short-circuit operation. */
3695 else if (BRANCH_COST
>= 2
3696 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3697 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3698 && operand_equal_p (lhs
, rhs
, 0))
3700 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3701 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3702 which cases we can't do this. */
3703 if (simple_operand_p (lhs
))
3704 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3705 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3706 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3707 TREE_OPERAND (exp
, 1));
3709 else if (global_bindings_p () == 0
3710 && ! contains_placeholder_p (lhs
))
3712 tree common
= save_expr (lhs
);
3714 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3715 or_op
? ! in0_p
: in0_p
,
3717 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3718 or_op
? ! in1_p
: in1_p
,
3720 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3721 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3722 TREE_TYPE (exp
), lhs
, rhs
);
3729 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3730 bit value. Arrange things so the extra bits will be set to zero if and
3731 only if C is signed-extended to its full width. If MASK is nonzero,
3732 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3735 unextend (c
, p
, unsignedp
, mask
)
3741 tree type
= TREE_TYPE (c
);
3742 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3745 if (p
== modesize
|| unsignedp
)
3748 /* We work by getting just the sign bit into the low-order bit, then
3749 into the high-order bit, then sign-extend. We then XOR that value
3751 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3752 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3754 /* We must use a signed type in order to get an arithmetic right shift.
3755 However, we must also avoid introducing accidental overflows, so that
3756 a subsequent call to integer_zerop will work. Hence we must
3757 do the type conversion here. At this point, the constant is either
3758 zero or one, and the conversion to a signed type can never overflow.
3759 We could get an overflow if this conversion is done anywhere else. */
3760 if (TREE_UNSIGNED (type
))
3761 temp
= convert (signed_type (type
), temp
);
3763 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3764 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3766 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3767 /* If necessary, convert the type back to match the type of C. */
3768 if (TREE_UNSIGNED (type
))
3769 temp
= convert (type
, temp
);
3771 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3774 /* Find ways of folding logical expressions of LHS and RHS:
3775 Try to merge two comparisons to the same innermost item.
3776 Look for range tests like "ch >= '0' && ch <= '9'".
3777 Look for combinations of simple terms on machines with expensive branches
3778 and evaluate the RHS unconditionally.
3780 For example, if we have p->a == 2 && p->b == 4 and we can make an
3781 object large enough to span both A and B, we can do this with a comparison
3782 against the object ANDed with the a mask.
3784 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3785 operations to do this with one comparison.
3787 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3788 function and the one above.
3790 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3791 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3793 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3796 We return the simplified tree or 0 if no optimization is possible. */
3799 fold_truthop (code
, truth_type
, lhs
, rhs
)
3800 enum tree_code code
;
3801 tree truth_type
, lhs
, rhs
;
3803 /* If this is the "or" of two comparisons, we can do something if we
3804 the comparisons are NE_EXPR. If this is the "and", we can do something
3805 if the comparisons are EQ_EXPR. I.e.,
3806 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3808 WANTED_CODE is this operation code. For single bit fields, we can
3809 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3810 comparison for one-bit fields. */
3812 enum tree_code wanted_code
;
3813 enum tree_code lcode
, rcode
;
3814 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3815 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3816 int ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3817 int rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3818 int xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3819 int lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3820 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3821 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3822 enum machine_mode lnmode
, rnmode
;
3823 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3824 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3825 tree l_const
, r_const
;
3826 tree lntype
, rntype
, result
;
3827 int first_bit
, end_bit
;
3830 /* Start by getting the comparison codes. Fail if anything is volatile.
3831 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3832 it were surrounded with a NE_EXPR. */
3834 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3837 lcode
= TREE_CODE (lhs
);
3838 rcode
= TREE_CODE (rhs
);
3840 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3841 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3843 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3844 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3846 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3849 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3850 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3852 ll_arg
= TREE_OPERAND (lhs
, 0);
3853 lr_arg
= TREE_OPERAND (lhs
, 1);
3854 rl_arg
= TREE_OPERAND (rhs
, 0);
3855 rr_arg
= TREE_OPERAND (rhs
, 1);
3857 /* If the RHS can be evaluated unconditionally and its operands are
3858 simple, it wins to evaluate the RHS unconditionally on machines
3859 with expensive branches. In this case, this isn't a comparison
3860 that can be merged. */
3862 /* @@ I'm not sure it wins on the m88110 to do this if the comparisons
3863 are with zero (tmw). */
3865 if (BRANCH_COST
>= 2
3866 && INTEGRAL_TYPE_P (TREE_TYPE (rhs
))
3867 && simple_operand_p (rl_arg
)
3868 && simple_operand_p (rr_arg
))
3869 return build (code
, truth_type
, lhs
, rhs
);
3871 /* See if the comparisons can be merged. Then get all the parameters for
3874 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3875 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3879 ll_inner
= decode_field_reference (ll_arg
,
3880 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3881 &ll_unsignedp
, &volatilep
, &ll_mask
,
3883 lr_inner
= decode_field_reference (lr_arg
,
3884 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3885 &lr_unsignedp
, &volatilep
, &lr_mask
,
3887 rl_inner
= decode_field_reference (rl_arg
,
3888 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3889 &rl_unsignedp
, &volatilep
, &rl_mask
,
3891 rr_inner
= decode_field_reference (rr_arg
,
3892 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3893 &rr_unsignedp
, &volatilep
, &rr_mask
,
3896 /* It must be true that the inner operation on the lhs of each
3897 comparison must be the same if we are to be able to do anything.
3898 Then see if we have constants. If not, the same must be true for
3900 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3901 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3904 if (TREE_CODE (lr_arg
) == INTEGER_CST
3905 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3906 l_const
= lr_arg
, r_const
= rr_arg
;
3907 else if (lr_inner
== 0 || rr_inner
== 0
3908 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3911 l_const
= r_const
= 0;
3913 /* If either comparison code is not correct for our logical operation,
3914 fail. However, we can convert a one-bit comparison against zero into
3915 the opposite comparison against that bit being set in the field. */
3917 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3918 if (lcode
!= wanted_code
)
3920 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3922 /* Make the left operand unsigned, since we are only interested
3923 in the value of one bit. Otherwise we are doing the wrong
3932 /* This is analogous to the code for l_const above. */
3933 if (rcode
!= wanted_code
)
3935 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3944 /* See if we can find a mode that contains both fields being compared on
3945 the left. If we can't, fail. Otherwise, update all constants and masks
3946 to be relative to a field of that size. */
3947 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3948 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3949 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3950 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3952 if (lnmode
== VOIDmode
)
3955 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3956 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3957 lntype
= type_for_size (lnbitsize
, 1);
3958 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3960 if (BYTES_BIG_ENDIAN
)
3962 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3963 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3966 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3967 size_int (xll_bitpos
), 0);
3968 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3969 size_int (xrl_bitpos
), 0);
3973 l_const
= convert (lntype
, l_const
);
3974 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3975 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3976 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3977 fold (build1 (BIT_NOT_EXPR
,
3981 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3983 return convert (truth_type
,
3984 wanted_code
== NE_EXPR
3985 ? integer_one_node
: integer_zero_node
);
3990 r_const
= convert (lntype
, r_const
);
3991 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3992 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3993 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3994 fold (build1 (BIT_NOT_EXPR
,
3998 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
4000 return convert (truth_type
,
4001 wanted_code
== NE_EXPR
4002 ? integer_one_node
: integer_zero_node
);
4006 /* If the right sides are not constant, do the same for it. Also,
4007 disallow this optimization if a size or signedness mismatch occurs
4008 between the left and right sides. */
4011 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
4012 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
4013 /* Make sure the two fields on the right
4014 correspond to the left without being swapped. */
4015 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
4018 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
4019 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
4020 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
4021 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
4023 if (rnmode
== VOIDmode
)
4026 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
4027 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
4028 rntype
= type_for_size (rnbitsize
, 1);
4029 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
4031 if (BYTES_BIG_ENDIAN
)
4033 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
4034 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
4037 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
4038 size_int (xlr_bitpos
), 0);
4039 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
4040 size_int (xrr_bitpos
), 0);
4042 /* Make a mask that corresponds to both fields being compared.
4043 Do this for both items being compared. If the operands are the
4044 same size and the bits being compared are in the same position
4045 then we can do this by masking both and comparing the masked
4047 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4048 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
4049 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
4051 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4052 ll_unsignedp
|| rl_unsignedp
);
4053 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4054 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
4056 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
4057 lr_unsignedp
|| rr_unsignedp
);
4058 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
4059 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
4061 return build (wanted_code
, truth_type
, lhs
, rhs
);
4064 /* There is still another way we can do something: If both pairs of
4065 fields being compared are adjacent, we may be able to make a wider
4066 field containing them both.
4068 Note that we still must mask the lhs/rhs expressions. Furthermore,
4069 the mask must be shifted to account for the shift done by
4070 make_bit_field_ref. */
4071 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
4072 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
4073 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
4074 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
4078 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
4079 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
4080 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
4081 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
4083 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
4084 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
4085 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
4086 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
4088 /* Convert to the smaller type before masking out unwanted bits. */
4090 if (lntype
!= rntype
)
4092 if (lnbitsize
> rnbitsize
)
4094 lhs
= convert (rntype
, lhs
);
4095 ll_mask
= convert (rntype
, ll_mask
);
4098 else if (lnbitsize
< rnbitsize
)
4100 rhs
= convert (lntype
, rhs
);
4101 lr_mask
= convert (lntype
, lr_mask
);
4106 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
4107 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
4109 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
4110 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
4112 return build (wanted_code
, truth_type
, lhs
, rhs
);
4118 /* Handle the case of comparisons with constants. If there is something in
4119 common between the masks, those bits of the constants must be the same.
4120 If not, the condition is always false. Test for this to avoid generating
4121 incorrect code below. */
4122 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
4123 if (! integer_zerop (result
)
4124 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
4125 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
4127 if (wanted_code
== NE_EXPR
)
4129 warning ("`or' of unmatched not-equal tests is always 1");
4130 return convert (truth_type
, integer_one_node
);
4134 warning ("`and' of mutually exclusive equal-tests is always 0");
4135 return convert (truth_type
, integer_zero_node
);
4139 /* Construct the expression we will return. First get the component
4140 reference we will make. Unless the mask is all ones the width of
4141 that field, perform the mask operation. Then compare with the
4143 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
4144 ll_unsignedp
|| rl_unsignedp
);
4146 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
4147 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
4148 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
4150 return build (wanted_code
, truth_type
, result
,
4151 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4154 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4158 optimize_minmax_comparison (t
)
4161 tree type
= TREE_TYPE (t
);
4162 tree arg0
= TREE_OPERAND (t
, 0);
4163 enum tree_code op_code
;
4164 tree comp_const
= TREE_OPERAND (t
, 1);
4166 int consts_equal
, consts_lt
;
4169 STRIP_SIGN_NOPS (arg0
);
4171 op_code
= TREE_CODE (arg0
);
4172 minmax_const
= TREE_OPERAND (arg0
, 1);
4173 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4174 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4175 inner
= TREE_OPERAND (arg0
, 0);
4177 /* If something does not permit us to optimize, return the original tree. */
4178 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4179 || TREE_CODE (comp_const
) != INTEGER_CST
4180 || TREE_CONSTANT_OVERFLOW (comp_const
)
4181 || TREE_CODE (minmax_const
) != INTEGER_CST
4182 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4185 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4186 and GT_EXPR, doing the rest with recursive calls using logical
4188 switch (TREE_CODE (t
))
4190 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4192 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4196 fold (build (TRUTH_ORIF_EXPR
, type
,
4197 optimize_minmax_comparison
4198 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4199 optimize_minmax_comparison
4200 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4203 if (op_code
== MAX_EXPR
&& consts_equal
)
4204 /* MAX (X, 0) == 0 -> X <= 0 */
4205 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4207 else if (op_code
== MAX_EXPR
&& consts_lt
)
4208 /* MAX (X, 0) == 5 -> X == 5 */
4209 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4211 else if (op_code
== MAX_EXPR
)
4212 /* MAX (X, 0) == -1 -> false */
4213 return omit_one_operand (type
, integer_zero_node
, inner
);
4215 else if (consts_equal
)
4216 /* MIN (X, 0) == 0 -> X >= 0 */
4217 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4220 /* MIN (X, 0) == 5 -> false */
4221 return omit_one_operand (type
, integer_zero_node
, inner
);
4224 /* MIN (X, 0) == -1 -> X == -1 */
4225 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4228 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4229 /* MAX (X, 0) > 0 -> X > 0
4230 MAX (X, 0) > 5 -> X > 5 */
4231 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4233 else if (op_code
== MAX_EXPR
)
4234 /* MAX (X, 0) > -1 -> true */
4235 return omit_one_operand (type
, integer_one_node
, inner
);
4237 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4238 /* MIN (X, 0) > 0 -> false
4239 MIN (X, 0) > 5 -> false */
4240 return omit_one_operand (type
, integer_zero_node
, inner
);
4243 /* MIN (X, 0) > -1 -> X > -1 */
4244 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4251 /* T is an integer expression that is being multiplied, divided, or taken a
4252 modulus (CODE says which and what kind of divide or modulus) by a
4253 constant C. See if we can eliminate that operation by folding it with
4254 other operations already in T. WIDE_TYPE, if non-null, is a type that
4255 should be used for the computation if wider than our type.
4257 For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
4258 (X * 2) + (Y + 4). We also canonicalize (X + 7) * 4 into X * 4 + 28
4259 in the hope that either the machine has a multiply-accumulate insn
4260 or that this is part of an addressing calculation.
4262 If we return a non-null expression, it is an equivalent form of the
4263 original computation, but need not be in the original type. */
4266 extract_muldiv (t
, c
, code
, wide_type
)
4269 enum tree_code code
;
4272 tree type
= TREE_TYPE (t
);
4273 enum tree_code tcode
= TREE_CODE (t
);
4274 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4275 > GET_MODE_SIZE (TYPE_MODE (type
)))
4276 ? wide_type
: type
);
4278 int same_p
= tcode
== code
;
4281 /* Don't deal with constants of zero here; they confuse the code below. */
4282 if (integer_zerop (c
))
4285 if (TREE_CODE_CLASS (tcode
) == '1')
4286 op0
= TREE_OPERAND (t
, 0);
4288 if (TREE_CODE_CLASS (tcode
) == '2')
4289 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4291 /* Note that we need not handle conditional operations here since fold
4292 already handles those cases. So just do arithmetic here. */
4296 /* For a constant, we can always simplify if we are a multiply
4297 or (for divide and modulus) if it is a multiple of our constant. */
4298 if (code
== MULT_EXPR
4299 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4300 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4303 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4305 /* Pass the constant down and see if we can make a simplification. If
4306 we can, replace this expression with the inner simplification for
4307 possible later conversion to our or some other type. */
4308 if (0 != (t1
= extract_muldiv (op0
, convert (TREE_TYPE (op0
), c
), code
,
4309 code
== MULT_EXPR
? ctype
: NULL_TREE
)))
4313 case NEGATE_EXPR
: case ABS_EXPR
:
4314 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4315 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4318 case MIN_EXPR
: case MAX_EXPR
:
4319 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4320 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4321 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4323 if (tree_int_cst_sgn (c
) < 0)
4324 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4326 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4327 convert (ctype
, t2
)));
4331 case WITH_RECORD_EXPR
:
4332 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4333 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4334 TREE_OPERAND (t
, 1));
4338 /* If this has not been evaluated and the operand has no side effects,
4339 we can see if we can do something inside it and make a new one.
4340 Note that this test is overly conservative since we can do this
4341 if the only reason it had side effects is that it was another
4342 similar SAVE_EXPR, but that isn't worth bothering with. */
4343 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4344 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4346 return save_expr (t1
);
4349 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4350 /* If the second operand is constant, this is a multiplication
4351 or floor division, by a power of two, so we can treat it that
4352 way unless the multiplier or divisor overflows. */
4353 if (TREE_CODE (op1
) == INTEGER_CST
4354 && 0 != (t1
= convert (ctype
,
4355 const_binop (LSHIFT_EXPR
, size_one_node
,
4357 && ! TREE_OVERFLOW (t1
))
4358 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4359 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4360 ctype
, convert (ctype
, op0
), t1
),
4361 c
, code
, wide_type
);
4364 case PLUS_EXPR
: case MINUS_EXPR
:
4365 /* See if we can eliminate the operation on both sides. If we can, we
4366 can return a new PLUS or MINUS. If we can't, the only remaining
4367 cases where we can do anything are if the second operand is a
4369 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4370 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4371 if (t1
!= 0 && t2
!= 0)
4372 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4373 convert (ctype
, t2
)));
4375 /* If this was a subtraction, negate OP1 and set it to be an addition.
4376 This simplifies the logic below. */
4377 if (tcode
== MINUS_EXPR
)
4378 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4380 if (TREE_CODE (op1
) != INTEGER_CST
)
4383 /* If either OP1 or C are negative, this optimization is not safe for
4384 some of the division and remainder types while for others we need
4385 to change the code. */
4386 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4388 if (code
== CEIL_DIV_EXPR
)
4389 code
= FLOOR_DIV_EXPR
;
4390 else if (code
== CEIL_MOD_EXPR
)
4391 code
= FLOOR_MOD_EXPR
;
4392 else if (code
== FLOOR_DIV_EXPR
)
4393 code
= CEIL_DIV_EXPR
;
4394 else if (code
== FLOOR_MOD_EXPR
)
4395 code
= CEIL_MOD_EXPR
;
4396 else if (code
!= MULT_EXPR
)
4400 /* Now do the operation and verify it doesn't overflow. */
4401 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4402 if (op1
== 0 || TREE_OVERFLOW (op1
))
4405 /* If we were able to eliminate our operation from the first side,
4406 apply our operation to the second side and reform the PLUS. */
4407 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4408 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4410 /* The last case is if we are a multiply. In that case, we can
4411 apply the distributive law to commute the multiply and addition
4412 if the multiplication of the constants doesn't overflow. */
4413 if (code
== MULT_EXPR
)
4414 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4415 convert (ctype
, op0
),
4416 convert (ctype
, c
))),
4422 /* We have a special case here if we are doing something like
4423 (C * 8) % 4 since we know that's zero. */
4424 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4425 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4426 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4427 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4428 return omit_one_operand (type
, integer_zero_node
, op0
);
4430 /* ... fall through ... */
4432 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4433 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4434 /* If we can extract our operation from the LHS, do so and return a
4435 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4436 do something only if the second operand is a constant. */
4438 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4439 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4440 convert (ctype
, op1
)));
4441 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4442 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4443 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4444 convert (ctype
, t1
)));
4445 else if (TREE_CODE (op1
) != INTEGER_CST
)
4448 /* If these are the same operation types, we can associate them
4449 assuming no overflow. */
4451 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4452 convert (ctype
, c
), 0))
4453 && ! TREE_OVERFLOW (t1
))
4454 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4456 /* If these operations "cancel" each other, we have the main
4457 optimizations of this pass, which occur when either constant is a
4458 multiple of the other, in which case we replace this with either an
4459 operation or CODE or TCODE. */
4460 if ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4461 || (tcode
== MULT_EXPR
4462 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4463 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
))
4465 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4466 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4468 const_binop (TRUNC_DIV_EXPR
,
4470 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4471 return fold (build (code
, ctype
, convert (ctype
, op0
),
4473 const_binop (TRUNC_DIV_EXPR
,
4485 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4486 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4487 that we may sometimes modify the tree. */
4490 strip_compound_expr (t
, s
)
4494 enum tree_code code
= TREE_CODE (t
);
4496 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4497 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4498 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4499 return TREE_OPERAND (t
, 1);
4501 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4502 don't bother handling any other types. */
4503 else if (code
== COND_EXPR
)
4505 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4506 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4507 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4509 else if (TREE_CODE_CLASS (code
) == '1')
4510 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4511 else if (TREE_CODE_CLASS (code
) == '<'
4512 || TREE_CODE_CLASS (code
) == '2')
4514 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4515 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4521 /* Return a node which has the indicated constant VALUE (either 0 or
4522 1), and is of the indicated TYPE. */
4525 constant_boolean_node (value
, type
)
4529 if (type
== integer_type_node
)
4530 return value
? integer_one_node
: integer_zero_node
;
4531 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4532 return truthvalue_conversion (value
? integer_one_node
:
4536 tree t
= build_int_2 (value
, 0);
4538 TREE_TYPE (t
) = type
;
4543 /* Utility function for the following routine, to see how complex a nesting of
4544 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4545 we don't care (to avoid spending too much time on complex expressions.). */
4548 count_cond (expr
, lim
)
4554 if (TREE_CODE (expr
) != COND_EXPR
)
4559 true = count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4560 false = count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - true);
4561 return MIN (lim
, 1 + true + false);
4564 /* Perform constant folding and related simplification of EXPR.
4565 The related simplifications include x*1 => x, x*0 => 0, etc.,
4566 and application of the associative law.
4567 NOP_EXPR conversions may be removed freely (as long as we
4568 are careful not to change the C type of the overall expression)
4569 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4570 but we can constant-fold them if they have constant operands. */
4576 register tree t
= expr
;
4577 tree t1
= NULL_TREE
;
4579 tree type
= TREE_TYPE (expr
);
4580 register tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4581 register enum tree_code code
= TREE_CODE (t
);
4584 /* WINS will be nonzero when the switch is done
4585 if all operands are constant. */
4588 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4589 Likewise for a SAVE_EXPR that's already been evaluated. */
4590 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
)) != 0)
4593 /* Return right away if already constant. */
4594 if (TREE_CONSTANT (t
))
4596 if (code
== CONST_DECL
)
4597 return DECL_INITIAL (t
);
4601 #ifdef MAX_INTEGER_COMPUTATION_MODE
4602 check_max_integer_computation_mode (expr
);
4605 kind
= TREE_CODE_CLASS (code
);
4606 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4610 /* Special case for conversion ops that can have fixed point args. */
4611 arg0
= TREE_OPERAND (t
, 0);
4613 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4615 STRIP_SIGN_NOPS (arg0
);
4617 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4618 subop
= TREE_REALPART (arg0
);
4622 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4623 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4624 && TREE_CODE (subop
) != REAL_CST
4625 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4627 /* Note that TREE_CONSTANT isn't enough:
4628 static var addresses are constant but we can't
4629 do arithmetic on them. */
4632 else if (kind
== 'e' || kind
== '<'
4633 || kind
== '1' || kind
== '2' || kind
== 'r')
4635 register int len
= tree_code_length
[(int) code
];
4637 for (i
= 0; i
< len
; i
++)
4639 tree op
= TREE_OPERAND (t
, i
);
4643 continue; /* Valid for CALL_EXPR, at least. */
4645 if (kind
== '<' || code
== RSHIFT_EXPR
)
4647 /* Signedness matters here. Perhaps we can refine this
4649 STRIP_SIGN_NOPS (op
);
4653 /* Strip any conversions that don't change the mode. */
4657 if (TREE_CODE (op
) == COMPLEX_CST
)
4658 subop
= TREE_REALPART (op
);
4662 if (TREE_CODE (subop
) != INTEGER_CST
4663 #if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
4664 && TREE_CODE (subop
) != REAL_CST
4665 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
4667 /* Note that TREE_CONSTANT isn't enough:
4668 static var addresses are constant but we can't
4669 do arithmetic on them. */
4679 /* If this is a commutative operation, and ARG0 is a constant, move it
4680 to ARG1 to reduce the number of tests below. */
4681 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
4682 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
4683 || code
== BIT_AND_EXPR
)
4684 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
4686 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
4688 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
4689 TREE_OPERAND (t
, 1) = tem
;
4692 /* Now WINS is set as described above,
4693 ARG0 is the first operand of EXPR,
4694 and ARG1 is the second operand (if it has more than one operand).
4696 First check for cases where an arithmetic operation is applied to a
4697 compound, conditional, or comparison operation. Push the arithmetic
4698 operation inside the compound or conditional to see if any folding
4699 can then be done. Convert comparison to conditional for this purpose.
4700 The also optimizes non-constant cases that used to be done in
4703 Before we do that, see if this is a BIT_AND_EXPR or a BIT_OR_EXPR,
4704 one of the operands is a comparison and the other is a comparison, a
4705 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4706 code below would make the expression more complex. Change it to a
4707 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4708 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4710 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
4711 || code
== EQ_EXPR
|| code
== NE_EXPR
)
4712 && ((truth_value_p (TREE_CODE (arg0
))
4713 && (truth_value_p (TREE_CODE (arg1
))
4714 || (TREE_CODE (arg1
) == BIT_AND_EXPR
4715 && integer_onep (TREE_OPERAND (arg1
, 1)))))
4716 || (truth_value_p (TREE_CODE (arg1
))
4717 && (truth_value_p (TREE_CODE (arg0
))
4718 || (TREE_CODE (arg0
) == BIT_AND_EXPR
4719 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
4721 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
4722 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
4726 if (code
== EQ_EXPR
)
4727 t
= invert_truthvalue (t
);
4732 if (TREE_CODE_CLASS (code
) == '1')
4734 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
4735 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4736 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
4737 else if (TREE_CODE (arg0
) == COND_EXPR
)
4739 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4740 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))),
4741 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 2)))));
4743 /* If this was a conversion, and all we did was to move into
4744 inside the COND_EXPR, bring it back out. But leave it if
4745 it is a conversion from integer to integer and the
4746 result precision is no wider than a word since such a
4747 conversion is cheap and may be optimized away by combine,
4748 while it couldn't if it were outside the COND_EXPR. Then return
4749 so we don't get into an infinite recursion loop taking the
4750 conversion out and then back in. */
4752 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
4753 || code
== NON_LVALUE_EXPR
)
4754 && TREE_CODE (t
) == COND_EXPR
4755 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
4756 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
4757 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
4758 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
4759 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
4761 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
4762 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
4763 t
= build1 (code
, type
,
4765 TREE_TYPE (TREE_OPERAND
4766 (TREE_OPERAND (t
, 1), 0)),
4767 TREE_OPERAND (t
, 0),
4768 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
4769 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
4772 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
4773 return fold (build (COND_EXPR
, type
, arg0
,
4774 fold (build1 (code
, type
, integer_one_node
)),
4775 fold (build1 (code
, type
, integer_zero_node
))));
4777 else if (TREE_CODE_CLASS (code
) == '2'
4778 || TREE_CODE_CLASS (code
) == '<')
4780 if (TREE_CODE (arg1
) == COMPOUND_EXPR
)
4781 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
4782 fold (build (code
, type
,
4783 arg0
, TREE_OPERAND (arg1
, 1))));
4784 else if ((TREE_CODE (arg1
) == COND_EXPR
4785 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
4786 && TREE_CODE_CLASS (code
) != '<'))
4787 && (TREE_CODE (arg0
) != COND_EXPR
4788 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
4789 && (! TREE_SIDE_EFFECTS (arg0
)
4790 || (global_bindings_p () == 0
4791 && ! contains_placeholder_p (arg0
))))
4793 tree test
, true_value
, false_value
;
4794 tree lhs
= 0, rhs
= 0;
4796 if (TREE_CODE (arg1
) == COND_EXPR
)
4798 test
= TREE_OPERAND (arg1
, 0);
4799 true_value
= TREE_OPERAND (arg1
, 1);
4800 false_value
= TREE_OPERAND (arg1
, 2);
4804 tree testtype
= TREE_TYPE (arg1
);
4806 true_value
= convert (testtype
, integer_one_node
);
4807 false_value
= convert (testtype
, integer_zero_node
);
4810 /* If ARG0 is complex we want to make sure we only evaluate
4811 it once. Though this is only required if it is volatile, it
4812 might be more efficient even if it is not. However, if we
4813 succeed in folding one part to a constant, we do not need
4814 to make this SAVE_EXPR. Since we do this optimization
4815 primarily to see if we do end up with constant and this
4816 SAVE_EXPR interferes with later optimizations, suppressing
4817 it when we can is important.
4819 If we are not in a function, we can't make a SAVE_EXPR, so don't
4820 try to do so. Don't try to see if the result is a constant
4821 if an arm is a COND_EXPR since we get exponential behavior
4824 if (TREE_CODE (arg0
) != SAVE_EXPR
&& ! TREE_CONSTANT (arg0
)
4825 && global_bindings_p () == 0
4826 && ((TREE_CODE (arg0
) != VAR_DECL
4827 && TREE_CODE (arg0
) != PARM_DECL
)
4828 || TREE_SIDE_EFFECTS (arg0
)))
4830 if (TREE_CODE (true_value
) != COND_EXPR
)
4831 lhs
= fold (build (code
, type
, arg0
, true_value
));
4833 if (TREE_CODE (false_value
) != COND_EXPR
)
4834 rhs
= fold (build (code
, type
, arg0
, false_value
));
4836 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4837 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4838 arg0
= save_expr (arg0
), lhs
= rhs
= 0;
4842 lhs
= fold (build (code
, type
, arg0
, true_value
));
4844 rhs
= fold (build (code
, type
, arg0
, false_value
));
4846 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4848 if (TREE_CODE (arg0
) == SAVE_EXPR
)
4849 return build (COMPOUND_EXPR
, type
,
4850 convert (void_type_node
, arg0
),
4851 strip_compound_expr (test
, arg0
));
4853 return convert (type
, test
);
4856 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
4857 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4858 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
4859 else if ((TREE_CODE (arg0
) == COND_EXPR
4860 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
4861 && TREE_CODE_CLASS (code
) != '<'))
4862 && (TREE_CODE (arg1
) != COND_EXPR
4863 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
4864 && (! TREE_SIDE_EFFECTS (arg1
)
4865 || (global_bindings_p () == 0
4866 && ! contains_placeholder_p (arg1
))))
4868 tree test
, true_value
, false_value
;
4869 tree lhs
= 0, rhs
= 0;
4871 if (TREE_CODE (arg0
) == COND_EXPR
)
4873 test
= TREE_OPERAND (arg0
, 0);
4874 true_value
= TREE_OPERAND (arg0
, 1);
4875 false_value
= TREE_OPERAND (arg0
, 2);
4879 tree testtype
= TREE_TYPE (arg0
);
4881 true_value
= convert (testtype
, integer_one_node
);
4882 false_value
= convert (testtype
, integer_zero_node
);
4885 if (TREE_CODE (arg1
) != SAVE_EXPR
&& ! TREE_CONSTANT (arg0
)
4886 && global_bindings_p () == 0
4887 && ((TREE_CODE (arg1
) != VAR_DECL
4888 && TREE_CODE (arg1
) != PARM_DECL
)
4889 || TREE_SIDE_EFFECTS (arg1
)))
4891 if (TREE_CODE (true_value
) != COND_EXPR
)
4892 lhs
= fold (build (code
, type
, true_value
, arg1
));
4894 if (TREE_CODE (false_value
) != COND_EXPR
)
4895 rhs
= fold (build (code
, type
, false_value
, arg1
));
4897 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4898 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4899 arg1
= save_expr (arg1
), lhs
= rhs
= 0;
4903 lhs
= fold (build (code
, type
, true_value
, arg1
));
4906 rhs
= fold (build (code
, type
, false_value
, arg1
));
4908 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4909 if (TREE_CODE (arg1
) == SAVE_EXPR
)
4910 return build (COMPOUND_EXPR
, type
,
4911 convert (void_type_node
, arg1
),
4912 strip_compound_expr (test
, arg1
));
4914 return convert (type
, test
);
4917 else if (TREE_CODE_CLASS (code
) == '<'
4918 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
4919 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4920 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
4921 else if (TREE_CODE_CLASS (code
) == '<'
4922 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
4923 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
4924 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
4936 return fold (DECL_INITIAL (t
));
4941 case FIX_TRUNC_EXPR
:
4942 /* Other kinds of FIX are not handled properly by fold_convert. */
4944 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
4945 return TREE_OPERAND (t
, 0);
4947 /* Handle cases of two conversions in a row. */
4948 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
4949 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
4951 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4952 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
4953 tree final_type
= TREE_TYPE (t
);
4954 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
4955 int inside_ptr
= POINTER_TYPE_P (inside_type
);
4956 int inside_float
= FLOAT_TYPE_P (inside_type
);
4957 int inside_prec
= TYPE_PRECISION (inside_type
);
4958 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
4959 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
4960 int inter_ptr
= POINTER_TYPE_P (inter_type
);
4961 int inter_float
= FLOAT_TYPE_P (inter_type
);
4962 int inter_prec
= TYPE_PRECISION (inter_type
);
4963 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
4964 int final_int
= INTEGRAL_TYPE_P (final_type
);
4965 int final_ptr
= POINTER_TYPE_P (final_type
);
4966 int final_float
= FLOAT_TYPE_P (final_type
);
4967 int final_prec
= TYPE_PRECISION (final_type
);
4968 int final_unsignedp
= TREE_UNSIGNED (final_type
);
4970 /* In addition to the cases of two conversions in a row
4971 handled below, if we are converting something to its own
4972 type via an object of identical or wider precision, neither
4973 conversion is needed. */
4974 if (inside_type
== final_type
4975 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
4976 && inter_prec
>= final_prec
)
4977 return TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
4979 /* Likewise, if the intermediate and final types are either both
4980 float or both integer, we don't need the middle conversion if
4981 it is wider than the final type and doesn't change the signedness
4982 (for integers). Avoid this if the final type is a pointer
4983 since then we sometimes need the inner conversion. Likewise if
4984 the outer has a precision not equal to the size of its mode. */
4985 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
4986 || (inter_float
&& inside_float
))
4987 && inter_prec
>= inside_prec
4988 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
4989 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
4990 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
4992 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4994 /* If we have a sign-extension of a zero-extended value, we can
4995 replace that by a single zero-extension. */
4996 if (inside_int
&& inter_int
&& final_int
4997 && inside_prec
< inter_prec
&& inter_prec
< final_prec
4998 && inside_unsignedp
&& !inter_unsignedp
)
4999 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5001 /* Two conversions in a row are not needed unless:
5002 - some conversion is floating-point (overstrict for now), or
5003 - the intermediate type is narrower than both initial and
5005 - the intermediate type and innermost type differ in signedness,
5006 and the outermost type is wider than the intermediate, or
5007 - the initial type is a pointer type and the precisions of the
5008 intermediate and final types differ, or
5009 - the final type is a pointer type and the precisions of the
5010 initial and intermediate types differ. */
5011 if (! inside_float
&& ! inter_float
&& ! final_float
5012 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5013 && ! (inside_int
&& inter_int
5014 && inter_unsignedp
!= inside_unsignedp
5015 && inter_prec
< final_prec
)
5016 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5017 == (final_unsignedp
&& final_prec
> inter_prec
))
5018 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5019 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5020 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5021 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5023 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5026 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5027 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5028 /* Detect assigning a bitfield. */
5029 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5030 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5032 /* Don't leave an assignment inside a conversion
5033 unless assigning a bitfield. */
5034 tree prev
= TREE_OPERAND (t
, 0);
5035 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5036 /* First do the assignment, then return converted constant. */
5037 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5043 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5046 return fold_convert (t
, arg0
);
5048 #if 0 /* This loses on &"foo"[0]. */
5053 /* Fold an expression like: "foo"[2] */
5054 if (TREE_CODE (arg0
) == STRING_CST
5055 && TREE_CODE (arg1
) == INTEGER_CST
5056 && !TREE_INT_CST_HIGH (arg1
)
5057 && (i
= TREE_INT_CST_LOW (arg1
)) < TREE_STRING_LENGTH (arg0
))
5059 t
= build_int_2 (TREE_STRING_POINTER (arg0
)[i
], 0);
5060 TREE_TYPE (t
) = TREE_TYPE (TREE_TYPE (arg0
));
5061 force_fit_type (t
, 0);
5068 if (TREE_CODE (arg0
) == CONSTRUCTOR
)
5070 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5077 TREE_CONSTANT (t
) = wins
;
5083 if (TREE_CODE (arg0
) == INTEGER_CST
)
5085 HOST_WIDE_INT low
, high
;
5086 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5087 TREE_INT_CST_HIGH (arg0
),
5089 t
= build_int_2 (low
, high
);
5090 TREE_TYPE (t
) = type
;
5092 = (TREE_OVERFLOW (arg0
)
5093 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5094 TREE_CONSTANT_OVERFLOW (t
)
5095 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5097 else if (TREE_CODE (arg0
) == REAL_CST
)
5098 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5100 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5101 return TREE_OPERAND (arg0
, 0);
5103 /* Convert - (a - b) to (b - a) for non-floating-point. */
5104 else if (TREE_CODE (arg0
) == MINUS_EXPR
5105 && (! FLOAT_TYPE_P (type
) || flag_fast_math
))
5106 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5107 TREE_OPERAND (arg0
, 0));
5114 if (TREE_CODE (arg0
) == INTEGER_CST
)
5116 if (! TREE_UNSIGNED (type
)
5117 && TREE_INT_CST_HIGH (arg0
) < 0)
5119 HOST_WIDE_INT low
, high
;
5120 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5121 TREE_INT_CST_HIGH (arg0
),
5123 t
= build_int_2 (low
, high
);
5124 TREE_TYPE (t
) = type
;
5126 = (TREE_OVERFLOW (arg0
)
5127 | force_fit_type (t
, overflow
));
5128 TREE_CONSTANT_OVERFLOW (t
)
5129 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5132 else if (TREE_CODE (arg0
) == REAL_CST
)
5134 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5135 t
= build_real (type
,
5136 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5139 else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
5140 return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5144 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5146 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5147 return build (COMPLEX_EXPR
, TREE_TYPE (arg0
),
5148 TREE_OPERAND (arg0
, 0),
5149 negate_expr (TREE_OPERAND (arg0
, 1)));
5150 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5151 return build_complex (type
, TREE_OPERAND (arg0
, 0),
5152 negate_expr (TREE_OPERAND (arg0
, 1)));
5153 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5154 return fold (build (TREE_CODE (arg0
), type
,
5155 fold (build1 (CONJ_EXPR
, type
,
5156 TREE_OPERAND (arg0
, 0))),
5157 fold (build1 (CONJ_EXPR
,
5158 type
, TREE_OPERAND (arg0
, 1)))));
5159 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5160 return TREE_OPERAND (arg0
, 0);
5166 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5167 ~ TREE_INT_CST_HIGH (arg0
));
5168 TREE_TYPE (t
) = type
;
5169 force_fit_type (t
, 0);
5170 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5171 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5173 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5174 return TREE_OPERAND (arg0
, 0);
5178 /* A + (-B) -> A - B */
5179 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5180 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5181 /* (-A) + B -> B - A */
5182 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5183 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5184 else if (! FLOAT_TYPE_P (type
))
5186 if (integer_zerop (arg1
))
5187 return non_lvalue (convert (type
, arg0
));
5189 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5190 with a constant, and the two constants have no bits in common,
5191 we should treat this as a BIT_IOR_EXPR since this may produce more
5193 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5194 && TREE_CODE (arg1
) == BIT_AND_EXPR
5195 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5196 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5197 && integer_zerop (const_binop (BIT_AND_EXPR
,
5198 TREE_OPERAND (arg0
, 1),
5199 TREE_OPERAND (arg1
, 1), 0)))
5201 code
= BIT_IOR_EXPR
;
5205 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5206 (plus (plus (mult) (mult)) (foo)) so that we can
5207 take advantage of the factoring cases below. */
5208 if ((TREE_CODE (arg0
) == PLUS_EXPR
5209 && TREE_CODE (arg1
) == MULT_EXPR
)
5210 || (TREE_CODE (arg1
) == PLUS_EXPR
5211 && TREE_CODE (arg0
) == MULT_EXPR
))
5213 tree parg0
, parg1
, parg
, marg
;
5215 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5216 parg
= arg0
, marg
= arg1
;
5218 parg
= arg1
, marg
= arg0
;
5219 parg0
= TREE_OPERAND (parg
, 0);
5220 parg1
= TREE_OPERAND (parg
, 1);
5224 if (TREE_CODE (parg0
) == MULT_EXPR
5225 && TREE_CODE (parg1
) != MULT_EXPR
)
5226 return fold (build (PLUS_EXPR
, type
,
5227 fold (build (PLUS_EXPR
, type
, parg0
, marg
)),
5229 if (TREE_CODE (parg0
) != MULT_EXPR
5230 && TREE_CODE (parg1
) == MULT_EXPR
)
5231 return fold (build (PLUS_EXPR
, type
,
5232 fold (build (PLUS_EXPR
, type
, parg1
, marg
)),
5236 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5238 tree arg00
, arg01
, arg10
, arg11
;
5239 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5241 /* (A * C) + (B * C) -> (A+B) * C.
5242 We are most concerned about the case where C is a constant,
5243 but other combinations show up during loop reduction. Since
5244 it is not difficult, try all four possibilities. */
5246 arg00
= TREE_OPERAND (arg0
, 0);
5247 arg01
= TREE_OPERAND (arg0
, 1);
5248 arg10
= TREE_OPERAND (arg1
, 0);
5249 arg11
= TREE_OPERAND (arg1
, 1);
5252 if (operand_equal_p (arg01
, arg11
, 0))
5253 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5254 else if (operand_equal_p (arg00
, arg10
, 0))
5255 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5256 else if (operand_equal_p (arg00
, arg11
, 0))
5257 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5258 else if (operand_equal_p (arg01
, arg10
, 0))
5259 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5261 /* No identical multiplicands; see if we can find a common
5262 power-of-two factor in non-power-of-two multiplies. This
5263 can help in multi-dimensional array access. */
5264 else if (TREE_CODE (arg01
) == INTEGER_CST
5265 && TREE_CODE (arg11
) == INTEGER_CST
5266 && TREE_INT_CST_HIGH (arg01
) == 0
5267 && TREE_INT_CST_HIGH (arg11
) == 0)
5269 HOST_WIDE_INT int01
, int11
, tmp
;
5270 int01
= TREE_INT_CST_LOW (arg01
);
5271 int11
= TREE_INT_CST_LOW (arg11
);
5273 /* Move min of absolute values to int11. */
5274 if ((int01
>= 0 ? int01
: -int01
)
5275 < (int11
>= 0 ? int11
: -int11
))
5277 tmp
= int01
, int01
= int11
, int11
= tmp
;
5278 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5279 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5282 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5284 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5285 build_int_2 (int01
/ int11
, 0)));
5292 return fold (build (MULT_EXPR
, type
,
5293 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5297 /* In IEEE floating point, x+0 may not equal x. */
5298 else if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5300 && real_zerop (arg1
))
5301 return non_lvalue (convert (type
, arg0
));
5302 /* x+(-0) equals x, even for IEEE. */
5303 else if (TREE_CODE (arg1
) == REAL_CST
5304 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
5305 return non_lvalue (convert (type
, arg0
));
5308 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5309 is a rotate of A by C1 bits. */
5310 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5311 is a rotate of A by B bits. */
5313 register enum tree_code code0
, code1
;
5314 code0
= TREE_CODE (arg0
);
5315 code1
= TREE_CODE (arg1
);
5316 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5317 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5318 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5319 TREE_OPERAND (arg1
,0), 0)
5320 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5322 register tree tree01
, tree11
;
5323 register enum tree_code code01
, code11
;
5325 tree01
= TREE_OPERAND (arg0
, 1);
5326 tree11
= TREE_OPERAND (arg1
, 1);
5327 STRIP_NOPS (tree01
);
5328 STRIP_NOPS (tree11
);
5329 code01
= TREE_CODE (tree01
);
5330 code11
= TREE_CODE (tree11
);
5331 if (code01
== INTEGER_CST
5332 && code11
== INTEGER_CST
5333 && TREE_INT_CST_HIGH (tree01
) == 0
5334 && TREE_INT_CST_HIGH (tree11
) == 0
5335 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5336 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5337 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5338 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5339 else if (code11
== MINUS_EXPR
)
5341 tree tree110
, tree111
;
5342 tree110
= TREE_OPERAND (tree11
, 0);
5343 tree111
= TREE_OPERAND (tree11
, 1);
5344 STRIP_NOPS (tree110
);
5345 STRIP_NOPS (tree111
);
5346 if (TREE_CODE (tree110
) == INTEGER_CST
5347 && TREE_INT_CST_HIGH (tree110
) == 0
5348 && (TREE_INT_CST_LOW (tree110
)
5349 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5350 && operand_equal_p (tree01
, tree111
, 0))
5351 return build ((code0
== LSHIFT_EXPR
5354 type
, TREE_OPERAND (arg0
, 0), tree01
);
5356 else if (code01
== MINUS_EXPR
)
5358 tree tree010
, tree011
;
5359 tree010
= TREE_OPERAND (tree01
, 0);
5360 tree011
= TREE_OPERAND (tree01
, 1);
5361 STRIP_NOPS (tree010
);
5362 STRIP_NOPS (tree011
);
5363 if (TREE_CODE (tree010
) == INTEGER_CST
5364 && TREE_INT_CST_HIGH (tree010
) == 0
5365 && (TREE_INT_CST_LOW (tree010
)
5366 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5367 && operand_equal_p (tree11
, tree011
, 0))
5368 return build ((code0
!= LSHIFT_EXPR
5371 type
, TREE_OPERAND (arg0
, 0), tree11
);
5378 /* In most languages, can't associate operations on floats through
5379 parentheses. Rather than remember where the parentheses were, we
5380 don't associate floats at all. It shouldn't matter much. However,
5381 associating multiplications is only very slightly inaccurate, so do
5382 that if -ffast-math is specified. */
5385 && (! FLOAT_TYPE_P (type
)
5386 || (flag_fast_math
&& code
!= MULT_EXPR
)))
5388 tree var0
, con0
, lit0
, var1
, con1
, lit1
;
5390 /* Split both trees into variables, constants, and literals. Then
5391 associate each group together, the constants with literals,
5392 then the result with variables. This increases the chances of
5393 literals being recombined later and of generating relocatable
5394 expressions for the sum of a constant and literal. */
5395 var0
= split_tree (arg0
, code
, &con0
, &lit0
, 0);
5396 var1
= split_tree (arg1
, code
, &con1
, &lit1
, code
== MINUS_EXPR
);
5398 /* Only do something if we found more than two objects. Otherwise,
5399 nothing has changed and we risk infinite recursion. */
5400 if (2 < ((var0
!= 0) + (var1
!= 0) + (con0
!= 0) + (con1
!= 0)
5401 + (lit0
!= 0) + (lit1
!= 0)))
5403 var0
= associate_trees (var0
, var1
, code
, type
);
5404 con0
= associate_trees (con0
, con1
, code
, type
);
5405 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5406 con0
= associate_trees (con0
, lit0
, code
, type
);
5407 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5412 #if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
5413 if (TREE_CODE (arg1
) == REAL_CST
)
5415 #endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
5417 t1
= const_binop (code
, arg0
, arg1
, 0);
5418 if (t1
!= NULL_TREE
)
5420 /* The return value should always have
5421 the same type as the original expression. */
5422 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5423 t1
= convert (TREE_TYPE (t
), t1
);
5430 /* A - (-B) -> A + B */
5431 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5432 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5433 /* (-A) - CST -> (-CST) - A for floating point (what about ints ?) */
5434 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
5436 fold (build (MINUS_EXPR
, type
,
5437 build_real (TREE_TYPE (arg1
),
5438 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
))),
5439 TREE_OPERAND (arg0
, 0)));
5441 if (! FLOAT_TYPE_P (type
))
5443 if (! wins
&& integer_zerop (arg0
))
5444 return negate_expr (arg1
);
5445 if (integer_zerop (arg1
))
5446 return non_lvalue (convert (type
, arg0
));
5448 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5449 about the case where C is a constant, just try one of the
5450 four possibilities. */
5452 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5453 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5454 TREE_OPERAND (arg1
, 1), 0))
5455 return fold (build (MULT_EXPR
, type
,
5456 fold (build (MINUS_EXPR
, type
,
5457 TREE_OPERAND (arg0
, 0),
5458 TREE_OPERAND (arg1
, 0))),
5459 TREE_OPERAND (arg0
, 1)));
5462 else if (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5465 /* Except with IEEE floating point, 0-x equals -x. */
5466 if (! wins
&& real_zerop (arg0
))
5467 return negate_expr (arg1
);
5468 /* Except with IEEE floating point, x-0 equals x. */
5469 if (real_zerop (arg1
))
5470 return non_lvalue (convert (type
, arg0
));
5473 /* Fold &x - &x. This can happen from &x.foo - &x.
5474 This is unsafe for certain floats even in non-IEEE formats.
5475 In IEEE, it is unsafe because it does wrong for NaNs.
5476 Also note that operand_equal_p is always false if an operand
5479 if ((! FLOAT_TYPE_P (type
) || flag_fast_math
)
5480 && operand_equal_p (arg0
, arg1
, 0))
5481 return convert (type
, integer_zero_node
);
5486 /* (-A) * (-B) -> A * B */
5487 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5488 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5489 TREE_OPERAND (arg1
, 0)));
5491 if (! FLOAT_TYPE_P (type
))
5493 if (integer_zerop (arg1
))
5494 return omit_one_operand (type
, arg1
, arg0
);
5495 if (integer_onep (arg1
))
5496 return non_lvalue (convert (type
, arg0
));
5498 /* (a * (1 << b)) is (a << b) */
5499 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5500 && integer_onep (TREE_OPERAND (arg1
, 0)))
5501 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5502 TREE_OPERAND (arg1
, 1)));
5503 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5504 && integer_onep (TREE_OPERAND (arg0
, 0)))
5505 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5506 TREE_OPERAND (arg0
, 1)));
5508 if (TREE_CODE (arg1
) == INTEGER_CST
5509 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5511 return convert (type
, tem
);
5516 /* x*0 is 0, except for IEEE floating point. */
5517 if ((TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
5519 && real_zerop (arg1
))
5520 return omit_one_operand (type
, arg1
, arg0
);
5521 /* In IEEE floating point, x*1 is not equivalent to x for snans.
5522 However, ANSI says we can drop signals,
5523 so we can do this anyway. */
5524 if (real_onep (arg1
))
5525 return non_lvalue (convert (type
, arg0
));
5527 if (! wins
&& real_twop (arg1
) && global_bindings_p () == 0
5528 && ! contains_placeholder_p (arg0
))
5530 tree arg
= save_expr (arg0
);
5531 return build (PLUS_EXPR
, type
, arg
, arg
);
5538 if (integer_all_onesp (arg1
))
5539 return omit_one_operand (type
, arg1
, arg0
);
5540 if (integer_zerop (arg1
))
5541 return non_lvalue (convert (type
, arg0
));
5542 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5543 if (t1
!= NULL_TREE
)
5546 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5548 This results in more efficient code for machines without a NAND
5549 instruction. Combine will canonicalize to the first form
5550 which will allow use of NAND instructions provided by the
5551 backend if they exist. */
5552 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5553 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5555 return fold (build1 (BIT_NOT_EXPR
, type
,
5556 build (BIT_AND_EXPR
, type
,
5557 TREE_OPERAND (arg0
, 0),
5558 TREE_OPERAND (arg1
, 0))));
5561 /* See if this can be simplified into a rotate first. If that
5562 is unsuccessful continue in the association code. */
5566 if (integer_zerop (arg1
))
5567 return non_lvalue (convert (type
, arg0
));
5568 if (integer_all_onesp (arg1
))
5569 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
5571 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5572 with a constant, and the two constants have no bits in common,
5573 we should treat this as a BIT_IOR_EXPR since this may produce more
5575 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5576 && TREE_CODE (arg1
) == BIT_AND_EXPR
5577 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5578 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5579 && integer_zerop (const_binop (BIT_AND_EXPR
,
5580 TREE_OPERAND (arg0
, 1),
5581 TREE_OPERAND (arg1
, 1), 0)))
5583 code
= BIT_IOR_EXPR
;
5587 /* See if this can be simplified into a rotate first. If that
5588 is unsuccessful continue in the association code. */
5593 if (integer_all_onesp (arg1
))
5594 return non_lvalue (convert (type
, arg0
));
5595 if (integer_zerop (arg1
))
5596 return omit_one_operand (type
, arg1
, arg0
);
5597 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5598 if (t1
!= NULL_TREE
)
5600 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5601 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == NOP_EXPR
5602 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1
, 0))))
5604 int prec
= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1
, 0)));
5605 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5606 && (~TREE_INT_CST_LOW (arg0
)
5607 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5608 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg1
, 0));
5610 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
5611 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5613 int prec
= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
5614 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5615 && (~TREE_INT_CST_LOW (arg1
)
5616 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5617 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5620 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5622 This results in more efficient code for machines without a NOR
5623 instruction. Combine will canonicalize to the first form
5624 which will allow use of NOR instructions provided by the
5625 backend if they exist. */
5626 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5627 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5629 return fold (build1 (BIT_NOT_EXPR
, type
,
5630 build (BIT_IOR_EXPR
, type
,
5631 TREE_OPERAND (arg0
, 0),
5632 TREE_OPERAND (arg1
, 0))));
5637 case BIT_ANDTC_EXPR
:
5638 if (integer_all_onesp (arg0
))
5639 return non_lvalue (convert (type
, arg1
));
5640 if (integer_zerop (arg0
))
5641 return omit_one_operand (type
, arg0
, arg1
);
5642 if (TREE_CODE (arg1
) == INTEGER_CST
)
5644 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
5645 code
= BIT_AND_EXPR
;
5651 /* In most cases, do nothing with a divide by zero. */
5652 #if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
5653 #ifndef REAL_INFINITY
5654 if (TREE_CODE (arg1
) == REAL_CST
&& real_zerop (arg1
))
5657 #endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
5659 /* (-A) / (-B) -> A / B */
5660 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5661 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5662 TREE_OPERAND (arg1
, 0)));
5664 /* In IEEE floating point, x/1 is not equivalent to x for snans.
5665 However, ANSI says we can drop signals, so we can do this anyway. */
5666 if (real_onep (arg1
))
5667 return non_lvalue (convert (type
, arg0
));
5669 /* If ARG1 is a constant, we can convert this to a multiply by the
5670 reciprocal. This does not have the same rounding properties,
5671 so only do this if -ffast-math. We can actually always safely
5672 do it if ARG1 is a power of two, but it's hard to tell if it is
5673 or not in a portable manner. */
5674 if (TREE_CODE (arg1
) == REAL_CST
)
5677 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
5679 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5680 /* Find the reciprocal if optimizing and the result is exact. */
5684 r
= TREE_REAL_CST (arg1
);
5685 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
5687 tem
= build_real (type
, r
);
5688 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5694 case TRUNC_DIV_EXPR
:
5695 case ROUND_DIV_EXPR
:
5696 case FLOOR_DIV_EXPR
:
5698 case EXACT_DIV_EXPR
:
5699 if (integer_onep (arg1
))
5700 return non_lvalue (convert (type
, arg0
));
5701 if (integer_zerop (arg1
))
5704 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5705 operation, EXACT_DIV_EXPR.
5707 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5708 At one time others generated faster code, it's not clear if they do
5709 after the last round to changes to the DIV code in expmed.c. */
5710 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
5711 && multiple_of_p (type
, arg0
, arg1
))
5712 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
5714 if (TREE_CODE (arg1
) == INTEGER_CST
5715 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5717 return convert (type
, tem
);
5722 case FLOOR_MOD_EXPR
:
5723 case ROUND_MOD_EXPR
:
5724 case TRUNC_MOD_EXPR
:
5725 if (integer_onep (arg1
))
5726 return omit_one_operand (type
, integer_zero_node
, arg0
);
5727 if (integer_zerop (arg1
))
5730 if (TREE_CODE (arg1
) == INTEGER_CST
5731 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5733 return convert (type
, tem
);
5741 if (integer_zerop (arg1
))
5742 return non_lvalue (convert (type
, arg0
));
5743 /* Since negative shift count is not well-defined,
5744 don't try to compute it in the compiler. */
5745 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
5747 /* Rewrite an LROTATE_EXPR by a constant into an
5748 RROTATE_EXPR by a new constant. */
5749 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
5751 TREE_SET_CODE (t
, RROTATE_EXPR
);
5752 code
= RROTATE_EXPR
;
5753 TREE_OPERAND (t
, 1) = arg1
5756 convert (TREE_TYPE (arg1
),
5757 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
5759 if (tree_int_cst_sgn (arg1
) < 0)
5763 /* If we have a rotate of a bit operation with the rotate count and
5764 the second operand of the bit operation both constant,
5765 permute the two operations. */
5766 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
5767 && (TREE_CODE (arg0
) == BIT_AND_EXPR
5768 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
5769 || TREE_CODE (arg0
) == BIT_IOR_EXPR
5770 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
5771 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
5772 return fold (build (TREE_CODE (arg0
), type
,
5773 fold (build (code
, type
,
5774 TREE_OPERAND (arg0
, 0), arg1
)),
5775 fold (build (code
, type
,
5776 TREE_OPERAND (arg0
, 1), arg1
))));
5778 /* Two consecutive rotates adding up to the width of the mode can
5780 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
5781 && TREE_CODE (arg0
) == RROTATE_EXPR
5782 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5783 && TREE_INT_CST_HIGH (arg1
) == 0
5784 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
5785 && ((TREE_INT_CST_LOW (arg1
)
5786 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
5787 == GET_MODE_BITSIZE (TYPE_MODE (type
))))
5788 return TREE_OPERAND (arg0
, 0);
5793 if (operand_equal_p (arg0
, arg1
, 0))
5795 if (INTEGRAL_TYPE_P (type
)
5796 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
5797 return omit_one_operand (type
, arg1
, arg0
);
5801 if (operand_equal_p (arg0
, arg1
, 0))
5803 if (INTEGRAL_TYPE_P (type
)
5804 && TYPE_MAX_VALUE (type
)
5805 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
5806 return omit_one_operand (type
, arg1
, arg0
);
5809 case TRUTH_NOT_EXPR
:
5810 /* Note that the operand of this must be an int
5811 and its values must be 0 or 1.
5812 ("true" is a fixed value perhaps depending on the language,
5813 but we don't handle values other than 1 correctly yet.) */
5814 tem
= invert_truthvalue (arg0
);
5815 /* Avoid infinite recursion. */
5816 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
5818 return convert (type
, tem
);
5820 case TRUTH_ANDIF_EXPR
:
5821 /* Note that the operands of this must be ints
5822 and their values must be 0 or 1.
5823 ("true" is a fixed value perhaps depending on the language.) */
5824 /* If first arg is constant zero, return it. */
5825 if (integer_zerop (arg0
))
5827 case TRUTH_AND_EXPR
:
5828 /* If either arg is constant true, drop it. */
5829 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
5830 return non_lvalue (arg1
);
5831 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
5832 return non_lvalue (arg0
);
5833 /* If second arg is constant zero, result is zero, but first arg
5834 must be evaluated. */
5835 if (integer_zerop (arg1
))
5836 return omit_one_operand (type
, arg1
, arg0
);
5837 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
5838 case will be handled here. */
5839 if (integer_zerop (arg0
))
5840 return omit_one_operand (type
, arg0
, arg1
);
5843 /* We only do these simplifications if we are optimizing. */
5847 /* Check for things like (A || B) && (A || C). We can convert this
5848 to A || (B && C). Note that either operator can be any of the four
5849 truth and/or operations and the transformation will still be
5850 valid. Also note that we only care about order for the
5851 ANDIF and ORIF operators. If B contains side effects, this
5852 might change the truth-value of A. */
5853 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
5854 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
5855 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
5856 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
5857 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
5858 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
5860 tree a00
= TREE_OPERAND (arg0
, 0);
5861 tree a01
= TREE_OPERAND (arg0
, 1);
5862 tree a10
= TREE_OPERAND (arg1
, 0);
5863 tree a11
= TREE_OPERAND (arg1
, 1);
5864 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
5865 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
5866 && (code
== TRUTH_AND_EXPR
5867 || code
== TRUTH_OR_EXPR
));
5869 if (operand_equal_p (a00
, a10
, 0))
5870 return fold (build (TREE_CODE (arg0
), type
, a00
,
5871 fold (build (code
, type
, a01
, a11
))));
5872 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
5873 return fold (build (TREE_CODE (arg0
), type
, a00
,
5874 fold (build (code
, type
, a01
, a10
))));
5875 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
5876 return fold (build (TREE_CODE (arg0
), type
, a01
,
5877 fold (build (code
, type
, a00
, a11
))));
5879 /* This case if tricky because we must either have commutative
5880 operators or else A10 must not have side-effects. */
5882 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
5883 && operand_equal_p (a01
, a11
, 0))
5884 return fold (build (TREE_CODE (arg0
), type
,
5885 fold (build (code
, type
, a00
, a10
)),
5889 /* See if we can build a range comparison. */
5890 if (0 != (tem
= fold_range_test (t
)))
5893 /* Check for the possibility of merging component references. If our
5894 lhs is another similar operation, try to merge its rhs with our
5895 rhs. Then try to merge our lhs and rhs. */
5896 if (TREE_CODE (arg0
) == code
5897 && 0 != (tem
= fold_truthop (code
, type
,
5898 TREE_OPERAND (arg0
, 1), arg1
)))
5899 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
5901 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
5906 case TRUTH_ORIF_EXPR
:
5907 /* Note that the operands of this must be ints
5908 and their values must be 0 or true.
5909 ("true" is a fixed value perhaps depending on the language.) */
5910 /* If first arg is constant true, return it. */
5911 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
5914 /* If either arg is constant zero, drop it. */
5915 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
5916 return non_lvalue (arg1
);
5917 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
))
5918 return non_lvalue (arg0
);
5919 /* If second arg is constant true, result is true, but we must
5920 evaluate first arg. */
5921 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
5922 return omit_one_operand (type
, arg1
, arg0
);
5923 /* Likewise for first arg, but note this only occurs here for
5925 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
5926 return omit_one_operand (type
, arg0
, arg1
);
5929 case TRUTH_XOR_EXPR
:
5930 /* If either arg is constant zero, drop it. */
5931 if (integer_zerop (arg0
))
5932 return non_lvalue (arg1
);
5933 if (integer_zerop (arg1
))
5934 return non_lvalue (arg0
);
5935 /* If either arg is constant true, this is a logical inversion. */
5936 if (integer_onep (arg0
))
5937 return non_lvalue (invert_truthvalue (arg1
));
5938 if (integer_onep (arg1
))
5939 return non_lvalue (invert_truthvalue (arg0
));
5948 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
5950 /* (-a) CMP (-b) -> b CMP a */
5951 if (TREE_CODE (arg0
) == NEGATE_EXPR
5952 && TREE_CODE (arg1
) == NEGATE_EXPR
)
5953 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
5954 TREE_OPERAND (arg0
, 0)));
5955 /* (-a) CMP CST -> a swap(CMP) (-CST) */
5956 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
5959 (swap_tree_comparison (code
), type
,
5960 TREE_OPERAND (arg0
, 0),
5961 build_real (TREE_TYPE (arg1
),
5962 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
)))));
5963 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
5964 /* a CMP (-0) -> a CMP 0 */
5965 if (TREE_CODE (arg1
) == REAL_CST
5966 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
5967 return fold (build (code
, type
, arg0
,
5968 build_real (TREE_TYPE (arg1
), dconst0
)));
5972 /* If one arg is a constant integer, put it last. */
5973 if (TREE_CODE (arg0
) == INTEGER_CST
5974 && TREE_CODE (arg1
) != INTEGER_CST
)
5976 TREE_OPERAND (t
, 0) = arg1
;
5977 TREE_OPERAND (t
, 1) = arg0
;
5978 arg0
= TREE_OPERAND (t
, 0);
5979 arg1
= TREE_OPERAND (t
, 1);
5980 code
= swap_tree_comparison (code
);
5981 TREE_SET_CODE (t
, code
);
5984 /* Convert foo++ == CONST into ++foo == CONST + INCR.
5985 First, see if one arg is constant; find the constant arg
5986 and the other one. */
5988 tree constop
= 0, varop
= NULL_TREE
;
5989 int constopnum
= -1;
5991 if (TREE_CONSTANT (arg1
))
5992 constopnum
= 1, constop
= arg1
, varop
= arg0
;
5993 if (TREE_CONSTANT (arg0
))
5994 constopnum
= 0, constop
= arg0
, varop
= arg1
;
5996 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
5998 /* This optimization is invalid for ordered comparisons
5999 if CONST+INCR overflows or if foo+incr might overflow.
6000 This optimization is invalid for floating point due to rounding.
6001 For pointer types we assume overflow doesn't happen. */
6002 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6003 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6004 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6007 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6008 constop
, TREE_OPERAND (varop
, 1)));
6009 TREE_SET_CODE (varop
, PREINCREMENT_EXPR
);
6011 /* If VAROP is a reference to a bitfield, we must mask
6012 the constant by the width of the field. */
6013 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6014 && DECL_BIT_FIELD(TREE_OPERAND
6015 (TREE_OPERAND (varop
, 0), 1)))
6018 = TREE_INT_CST_LOW (DECL_SIZE
6020 (TREE_OPERAND (varop
, 0), 1)));
6021 tree mask
, unsigned_type
;
6023 tree folded_compare
;
6025 /* First check whether the comparison would come out
6026 always the same. If we don't do that we would
6027 change the meaning with the masking. */
6028 if (constopnum
== 0)
6029 folded_compare
= fold (build (code
, type
, constop
,
6030 TREE_OPERAND (varop
, 0)));
6032 folded_compare
= fold (build (code
, type
,
6033 TREE_OPERAND (varop
, 0),
6035 if (integer_zerop (folded_compare
)
6036 || integer_onep (folded_compare
))
6037 return omit_one_operand (type
, folded_compare
, varop
);
6039 unsigned_type
= type_for_size (size
, 1);
6040 precision
= TYPE_PRECISION (unsigned_type
);
6041 mask
= build_int_2 (~0, ~0);
6042 TREE_TYPE (mask
) = unsigned_type
;
6043 force_fit_type (mask
, 0);
6044 mask
= const_binop (RSHIFT_EXPR
, mask
,
6045 size_int (precision
- size
), 0);
6046 newconst
= fold (build (BIT_AND_EXPR
,
6047 TREE_TYPE (varop
), newconst
,
6048 convert (TREE_TYPE (varop
),
6053 t
= build (code
, type
, TREE_OPERAND (t
, 0),
6054 TREE_OPERAND (t
, 1));
6055 TREE_OPERAND (t
, constopnum
) = newconst
;
6059 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6061 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6062 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6063 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6066 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6067 constop
, TREE_OPERAND (varop
, 1)));
6068 TREE_SET_CODE (varop
, PREDECREMENT_EXPR
);
6070 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6071 && DECL_BIT_FIELD(TREE_OPERAND
6072 (TREE_OPERAND (varop
, 0), 1)))
6075 = TREE_INT_CST_LOW (DECL_SIZE
6077 (TREE_OPERAND (varop
, 0), 1)));
6078 tree mask
, unsigned_type
;
6080 tree folded_compare
;
6082 if (constopnum
== 0)
6083 folded_compare
= fold (build (code
, type
, constop
,
6084 TREE_OPERAND (varop
, 0)));
6086 folded_compare
= fold (build (code
, type
,
6087 TREE_OPERAND (varop
, 0),
6089 if (integer_zerop (folded_compare
)
6090 || integer_onep (folded_compare
))
6091 return omit_one_operand (type
, folded_compare
, varop
);
6093 unsigned_type
= type_for_size (size
, 1);
6094 precision
= TYPE_PRECISION (unsigned_type
);
6095 mask
= build_int_2 (~0, ~0);
6096 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6097 force_fit_type (mask
, 0);
6098 mask
= const_binop (RSHIFT_EXPR
, mask
,
6099 size_int (precision
- size
), 0);
6100 newconst
= fold (build (BIT_AND_EXPR
,
6101 TREE_TYPE (varop
), newconst
,
6102 convert (TREE_TYPE (varop
),
6107 t
= build (code
, type
, TREE_OPERAND (t
, 0),
6108 TREE_OPERAND (t
, 1));
6109 TREE_OPERAND (t
, constopnum
) = newconst
;
6115 /* Change X >= CST to X > (CST - 1) if CST is positive. */
6116 if (TREE_CODE (arg1
) == INTEGER_CST
6117 && TREE_CODE (arg0
) != INTEGER_CST
6118 && tree_int_cst_sgn (arg1
) > 0)
6120 switch (TREE_CODE (t
))
6124 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6125 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6130 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6131 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6139 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6140 a MINUS_EXPR of a constant, we can convert it into a comparison with
6141 a revised constant as long as no overflow occurs. */
6142 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6143 && TREE_CODE (arg1
) == INTEGER_CST
6144 && (TREE_CODE (arg0
) == PLUS_EXPR
6145 || TREE_CODE (arg0
) == MINUS_EXPR
)
6146 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6147 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6148 ? MINUS_EXPR
: PLUS_EXPR
,
6149 arg1
, TREE_OPERAND (arg0
, 1), 0))
6150 && ! TREE_CONSTANT_OVERFLOW (tem
))
6151 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6153 /* Similarly for a NEGATE_EXPR. */
6154 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6155 && TREE_CODE (arg0
) == NEGATE_EXPR
6156 && TREE_CODE (arg1
) == INTEGER_CST
6157 && 0 != (tem
= negate_expr (arg1
))
6158 && TREE_CODE (tem
) == INTEGER_CST
6159 && ! TREE_CONSTANT_OVERFLOW (tem
))
6160 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6162 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6163 for !=. Don't do this for ordered comparisons due to overflow. */
6164 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6165 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6166 return fold (build (code
, type
,
6167 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6169 /* If we are widening one operand of an integer comparison,
6170 see if the other operand is similarly being widened. Perhaps we
6171 can do the comparison in the narrower type. */
6172 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6173 && TREE_CODE (arg0
) == NOP_EXPR
6174 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6175 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6176 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6177 || (TREE_CODE (t1
) == INTEGER_CST
6178 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6179 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6181 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6182 constant, we can simplify it. */
6183 else if (TREE_CODE (arg1
) == INTEGER_CST
6184 && (TREE_CODE (arg0
) == MIN_EXPR
6185 || TREE_CODE (arg0
) == MAX_EXPR
)
6186 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6187 return optimize_minmax_comparison (t
);
6189 /* If we are comparing an ABS_EXPR with a constant, we can
6190 convert all the cases into explicit comparisons, but they may
6191 well not be faster than doing the ABS and one comparison.
6192 But ABS (X) <= C is a range comparison, which becomes a subtraction
6193 and a comparison, and is probably faster. */
6194 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6195 && TREE_CODE (arg0
) == ABS_EXPR
6196 && ! TREE_SIDE_EFFECTS (arg0
)
6197 && (0 != (tem
= negate_expr (arg1
)))
6198 && TREE_CODE (tem
) == INTEGER_CST
6199 && ! TREE_CONSTANT_OVERFLOW (tem
))
6200 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6201 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6202 build (LE_EXPR
, type
,
6203 TREE_OPERAND (arg0
, 0), arg1
)));
6205 /* If this is an EQ or NE comparison with zero and ARG0 is
6206 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6207 two operations, but the latter can be done in one less insn
6208 on machines that have only two-operand insns or on which a
6209 constant cannot be the first operand. */
6210 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6211 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6213 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6214 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6216 fold (build (code
, type
,
6217 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6219 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6220 TREE_OPERAND (arg0
, 1),
6221 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6222 convert (TREE_TYPE (arg0
),
6225 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6226 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6228 fold (build (code
, type
,
6229 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6231 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6232 TREE_OPERAND (arg0
, 0),
6233 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6234 convert (TREE_TYPE (arg0
),
6239 /* If this is an NE or EQ comparison of zero against the result of a
6240 signed MOD operation whose second operand is a power of 2, make
6241 the MOD operation unsigned since it is simpler and equivalent. */
6242 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6243 && integer_zerop (arg1
)
6244 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6245 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6246 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6247 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6248 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6249 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6251 tree newtype
= unsigned_type (TREE_TYPE (arg0
));
6252 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6253 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6254 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6256 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6259 /* If this is an NE comparison of zero with an AND of one, remove the
6260 comparison since the AND will give the correct value. */
6261 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6262 && TREE_CODE (arg0
) == BIT_AND_EXPR
6263 && integer_onep (TREE_OPERAND (arg0
, 1)))
6264 return convert (type
, arg0
);
6266 /* If we have (A & C) == C where C is a power of 2, convert this into
6267 (A & C) != 0. Similarly for NE_EXPR. */
6268 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6269 && TREE_CODE (arg0
) == BIT_AND_EXPR
6270 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6271 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6272 return build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6273 arg0
, integer_zero_node
);
6275 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6276 and similarly for >= into !=. */
6277 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6278 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6279 && TREE_CODE (arg1
) == LSHIFT_EXPR
6280 && integer_onep (TREE_OPERAND (arg1
, 0)))
6281 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6282 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6283 TREE_OPERAND (arg1
, 1)),
6284 convert (TREE_TYPE (arg0
), integer_zero_node
));
6286 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6287 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6288 && (TREE_CODE (arg1
) == NOP_EXPR
6289 || TREE_CODE (arg1
) == CONVERT_EXPR
)
6290 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
6291 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
6293 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6294 convert (TREE_TYPE (arg0
),
6295 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6296 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
6297 convert (TREE_TYPE (arg0
), integer_zero_node
));
6299 /* Simplify comparison of something with itself. (For IEEE
6300 floating-point, we can only do some of these simplifications.) */
6301 if (operand_equal_p (arg0
, arg1
, 0))
6308 if (INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
6309 return constant_boolean_node (1, type
);
6311 TREE_SET_CODE (t
, code
);
6315 /* For NE, we can only do this simplification if integer. */
6316 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
)))
6318 /* ... fall through ... */
6321 return constant_boolean_node (0, type
);
6327 /* An unsigned comparison against 0 can be simplified. */
6328 if (integer_zerop (arg1
)
6329 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6330 || POINTER_TYPE_P (TREE_TYPE (arg1
)))
6331 && TREE_UNSIGNED (TREE_TYPE (arg1
)))
6333 switch (TREE_CODE (t
))
6337 TREE_SET_CODE (t
, NE_EXPR
);
6341 TREE_SET_CODE (t
, EQ_EXPR
);
6344 return omit_one_operand (type
,
6345 convert (type
, integer_one_node
),
6348 return omit_one_operand (type
,
6349 convert (type
, integer_zero_node
),
6356 /* Comparisons with the highest or lowest possible integer of
6357 the specified size will have known values and an unsigned
6358 <= 0x7fffffff can be simplified. */
6360 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6362 if (TREE_CODE (arg1
) == INTEGER_CST
6363 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6364 && width
<= HOST_BITS_PER_WIDE_INT
6365 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6366 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6368 if (TREE_INT_CST_HIGH (arg1
) == 0
6369 && (TREE_INT_CST_LOW (arg1
)
6370 == ((HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6371 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6372 switch (TREE_CODE (t
))
6375 return omit_one_operand (type
,
6376 convert (type
, integer_zero_node
),
6379 TREE_SET_CODE (t
, EQ_EXPR
);
6383 return omit_one_operand (type
,
6384 convert (type
, integer_one_node
),
6387 TREE_SET_CODE (t
, NE_EXPR
);
6394 else if (TREE_INT_CST_HIGH (arg1
) == -1
6395 && (- TREE_INT_CST_LOW (arg1
)
6396 == ((HOST_WIDE_INT
) 1 << (width
- 1)))
6397 && ! TREE_UNSIGNED (TREE_TYPE (arg1
)))
6398 switch (TREE_CODE (t
))
6401 return omit_one_operand (type
,
6402 convert (type
, integer_zero_node
),
6405 TREE_SET_CODE (t
, EQ_EXPR
);
6409 return omit_one_operand (type
,
6410 convert (type
, integer_one_node
),
6413 TREE_SET_CODE (t
, NE_EXPR
);
6420 else if (TREE_INT_CST_HIGH (arg1
) == 0
6421 && (TREE_INT_CST_LOW (arg1
)
6422 == ((HOST_WIDE_INT
) 1 << (width
- 1)) - 1)
6423 && TREE_UNSIGNED (TREE_TYPE (arg1
)))
6425 switch (TREE_CODE (t
))
6428 return fold (build (GE_EXPR
, type
,
6429 convert (signed_type (TREE_TYPE (arg0
)),
6431 convert (signed_type (TREE_TYPE (arg1
)),
6432 integer_zero_node
)));
6434 return fold (build (LT_EXPR
, type
,
6435 convert (signed_type (TREE_TYPE (arg0
)),
6437 convert (signed_type (TREE_TYPE (arg1
)),
6438 integer_zero_node
)));
6446 /* If we are comparing an expression that just has comparisons
6447 of two integer values, arithmetic expressions of those comparisons,
6448 and constants, we can simplify it. There are only three cases
6449 to check: the two values can either be equal, the first can be
6450 greater, or the second can be greater. Fold the expression for
6451 those three values. Since each value must be 0 or 1, we have
6452 eight possibilities, each of which corresponds to the constant 0
6453 or 1 or one of the six possible comparisons.
6455 This handles common cases like (a > b) == 0 but also handles
6456 expressions like ((x > y) - (y > x)) > 0, which supposedly
6457 occur in macroized code. */
6459 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
6461 tree cval1
= 0, cval2
= 0;
6464 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
6465 /* Don't handle degenerate cases here; they should already
6466 have been handled anyway. */
6467 && cval1
!= 0 && cval2
!= 0
6468 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
6469 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
6470 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
6471 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
6472 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
6473 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
6474 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
6476 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
6477 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
6479 /* We can't just pass T to eval_subst in case cval1 or cval2
6480 was the same as ARG1. */
6483 = fold (build (code
, type
,
6484 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
6487 = fold (build (code
, type
,
6488 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
6491 = fold (build (code
, type
,
6492 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
6495 /* All three of these results should be 0 or 1. Confirm they
6496 are. Then use those values to select the proper code
6499 if ((integer_zerop (high_result
)
6500 || integer_onep (high_result
))
6501 && (integer_zerop (equal_result
)
6502 || integer_onep (equal_result
))
6503 && (integer_zerop (low_result
)
6504 || integer_onep (low_result
)))
6506 /* Make a 3-bit mask with the high-order bit being the
6507 value for `>', the next for '=', and the low for '<'. */
6508 switch ((integer_onep (high_result
) * 4)
6509 + (integer_onep (equal_result
) * 2)
6510 + integer_onep (low_result
))
6514 return omit_one_operand (type
, integer_zero_node
, arg0
);
6535 return omit_one_operand (type
, integer_one_node
, arg0
);
6538 t
= build (code
, type
, cval1
, cval2
);
6540 return save_expr (t
);
6547 /* If this is a comparison of a field, we may be able to simplify it. */
6548 if ((TREE_CODE (arg0
) == COMPONENT_REF
6549 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
6550 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6551 /* Handle the constant case even without -O
6552 to make sure the warnings are given. */
6553 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
6555 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
6559 /* If this is a comparison of complex values and either or both sides
6560 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6561 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6562 This may prevent needless evaluations. */
6563 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6564 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
6565 && (TREE_CODE (arg0
) == COMPLEX_EXPR
6566 || TREE_CODE (arg1
) == COMPLEX_EXPR
6567 || TREE_CODE (arg0
) == COMPLEX_CST
6568 || TREE_CODE (arg1
) == COMPLEX_CST
))
6570 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
6571 tree real0
, imag0
, real1
, imag1
;
6573 arg0
= save_expr (arg0
);
6574 arg1
= save_expr (arg1
);
6575 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
6576 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
6577 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
6578 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
6580 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
6583 fold (build (code
, type
, real0
, real1
)),
6584 fold (build (code
, type
, imag0
, imag1
))));
6587 /* From here on, the only cases we handle are when the result is
6588 known to be a constant.
6590 To compute GT, swap the arguments and do LT.
6591 To compute GE, do LT and invert the result.
6592 To compute LE, swap the arguments, do LT and invert the result.
6593 To compute NE, do EQ and invert the result.
6595 Therefore, the code below must handle only EQ and LT. */
6597 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6599 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
6600 code
= swap_tree_comparison (code
);
6603 /* Note that it is safe to invert for real values here because we
6604 will check below in the one case that it matters. */
6608 if (code
== NE_EXPR
|| code
== GE_EXPR
)
6611 code
= invert_tree_comparison (code
);
6614 /* Compute a result for LT or EQ if args permit;
6615 otherwise return T. */
6616 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
6618 if (code
== EQ_EXPR
)
6619 t1
= build_int_2 ((TREE_INT_CST_LOW (arg0
)
6620 == TREE_INT_CST_LOW (arg1
))
6621 && (TREE_INT_CST_HIGH (arg0
)
6622 == TREE_INT_CST_HIGH (arg1
)),
6625 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
6626 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
6627 : INT_CST_LT (arg0
, arg1
)),
6631 #if 0 /* This is no longer useful, but breaks some real code. */
6632 /* Assume a nonexplicit constant cannot equal an explicit one,
6633 since such code would be undefined anyway.
6634 Exception: on sysvr4, using #pragma weak,
6635 a label can come out as 0. */
6636 else if (TREE_CODE (arg1
) == INTEGER_CST
6637 && !integer_zerop (arg1
)
6638 && TREE_CONSTANT (arg0
)
6639 && TREE_CODE (arg0
) == ADDR_EXPR
6641 t1
= build_int_2 (0, 0);
6643 /* Two real constants can be compared explicitly. */
6644 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
6646 /* If either operand is a NaN, the result is false with two
6647 exceptions: First, an NE_EXPR is true on NaNs, but that case
6648 is already handled correctly since we will be inverting the
6649 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6650 or a GE_EXPR into a LT_EXPR, we must return true so that it
6651 will be inverted into false. */
6653 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
6654 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
6655 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
6657 else if (code
== EQ_EXPR
)
6658 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
6659 TREE_REAL_CST (arg1
)),
6662 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
6663 TREE_REAL_CST (arg1
)),
6667 if (t1
== NULL_TREE
)
6671 TREE_INT_CST_LOW (t1
) ^= 1;
6673 TREE_TYPE (t1
) = type
;
6674 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
6675 return truthvalue_conversion (t1
);
6679 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6680 so all simple results must be passed through pedantic_non_lvalue. */
6681 if (TREE_CODE (arg0
) == INTEGER_CST
)
6682 return pedantic_non_lvalue
6683 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
6684 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
6685 return pedantic_omit_one_operand (type
, arg1
, arg0
);
6687 /* If the second operand is zero, invert the comparison and swap
6688 the second and third operands. Likewise if the second operand
6689 is constant and the third is not or if the third operand is
6690 equivalent to the first operand of the comparison. */
6692 if (integer_zerop (arg1
)
6693 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
6694 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
6695 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
6696 TREE_OPERAND (t
, 2),
6697 TREE_OPERAND (arg0
, 1))))
6699 /* See if this can be inverted. If it can't, possibly because
6700 it was a floating-point inequality comparison, don't do
6702 tem
= invert_truthvalue (arg0
);
6704 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
6706 t
= build (code
, type
, tem
,
6707 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
6709 /* arg1 should be the first argument of the new T. */
6710 arg1
= TREE_OPERAND (t
, 1);
6715 /* If we have A op B ? A : C, we may be able to convert this to a
6716 simpler expression, depending on the operation and the values
6717 of B and C. IEEE floating point prevents this though,
6718 because A or B might be -0.0 or a NaN. */
6720 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
6721 && (TARGET_FLOAT_FORMAT
!= IEEE_FLOAT_FORMAT
6722 || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 0)))
6724 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
6725 arg1
, TREE_OPERAND (arg0
, 1)))
6727 tree arg2
= TREE_OPERAND (t
, 2);
6728 enum tree_code comp_code
= TREE_CODE (arg0
);
6732 /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
6733 depending on the comparison operation. */
6734 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
6735 ? real_zerop (TREE_OPERAND (arg0
, 1))
6736 : integer_zerop (TREE_OPERAND (arg0
, 1)))
6737 && TREE_CODE (arg2
) == NEGATE_EXPR
6738 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
6742 return pedantic_non_lvalue (negate_expr (arg1
));
6744 return pedantic_non_lvalue (convert (type
, arg1
));
6747 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6748 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
6749 return pedantic_non_lvalue
6750 (convert (type
, fold (build1 (ABS_EXPR
,
6751 TREE_TYPE (arg1
), arg1
))));
6754 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6755 arg1
= convert (signed_type (TREE_TYPE (arg1
)), arg1
);
6756 return pedantic_non_lvalue
6757 (negate_expr (convert (type
,
6758 fold (build1 (ABS_EXPR
,
6765 /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
6768 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
6770 if (comp_code
== NE_EXPR
)
6771 return pedantic_non_lvalue (convert (type
, arg1
));
6772 else if (comp_code
== EQ_EXPR
)
6773 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
6776 /* If this is A op B ? A : B, this is either A, B, min (A, B),
6777 or max (A, B), depending on the operation. */
6779 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
6780 arg2
, TREE_OPERAND (arg0
, 0)))
6782 tree comp_op0
= TREE_OPERAND (arg0
, 0);
6783 tree comp_op1
= TREE_OPERAND (arg0
, 1);
6784 tree comp_type
= TREE_TYPE (comp_op0
);
6789 return pedantic_non_lvalue (convert (type
, arg2
));
6791 return pedantic_non_lvalue (convert (type
, arg1
));
6794 /* In C++ a ?: expression can be an lvalue, so put the
6795 operand which will be used if they are equal first
6796 so that we can convert this back to the
6797 corresponding COND_EXPR. */
6798 return pedantic_non_lvalue
6799 (convert (type
, (fold (build (MIN_EXPR
, comp_type
,
6800 (comp_code
== LE_EXPR
6801 ? comp_op0
: comp_op1
),
6802 (comp_code
== LE_EXPR
6803 ? comp_op1
: comp_op0
))))));
6807 return pedantic_non_lvalue
6808 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
6809 (comp_code
== GE_EXPR
6810 ? comp_op0
: comp_op1
),
6811 (comp_code
== GE_EXPR
6812 ? comp_op1
: comp_op0
)))));
6819 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
6820 we might still be able to simplify this. For example,
6821 if C1 is one less or one more than C2, this might have started
6822 out as a MIN or MAX and been transformed by this function.
6823 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
6825 if (INTEGRAL_TYPE_P (type
)
6826 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6827 && TREE_CODE (arg2
) == INTEGER_CST
)
6831 /* We can replace A with C1 in this case. */
6832 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
6833 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
6834 TREE_OPERAND (t
, 2));
6838 /* If C1 is C2 + 1, this is min(A, C2). */
6839 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
6840 && operand_equal_p (TREE_OPERAND (arg0
, 1),
6841 const_binop (PLUS_EXPR
, arg2
,
6842 integer_one_node
, 0), 1))
6843 return pedantic_non_lvalue
6844 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
6848 /* If C1 is C2 - 1, this is min(A, C2). */
6849 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
6850 && operand_equal_p (TREE_OPERAND (arg0
, 1),
6851 const_binop (MINUS_EXPR
, arg2
,
6852 integer_one_node
, 0), 1))
6853 return pedantic_non_lvalue
6854 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
6858 /* If C1 is C2 - 1, this is max(A, C2). */
6859 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
6860 && operand_equal_p (TREE_OPERAND (arg0
, 1),
6861 const_binop (MINUS_EXPR
, arg2
,
6862 integer_one_node
, 0), 1))
6863 return pedantic_non_lvalue
6864 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
6868 /* If C1 is C2 + 1, this is max(A, C2). */
6869 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
6870 && operand_equal_p (TREE_OPERAND (arg0
, 1),
6871 const_binop (PLUS_EXPR
, arg2
,
6872 integer_one_node
, 0), 1))
6873 return pedantic_non_lvalue
6874 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
6883 /* If the second operand is simpler than the third, swap them
6884 since that produces better jump optimization results. */
6885 if ((TREE_CONSTANT (arg1
) || TREE_CODE_CLASS (TREE_CODE (arg1
)) == 'd'
6886 || TREE_CODE (arg1
) == SAVE_EXPR
)
6887 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
6888 || TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (t
, 2))) == 'd'
6889 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
6891 /* See if this can be inverted. If it can't, possibly because
6892 it was a floating-point inequality comparison, don't do
6894 tem
= invert_truthvalue (arg0
);
6896 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
6898 t
= build (code
, type
, tem
,
6899 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
6901 /* arg1 should be the first argument of the new T. */
6902 arg1
= TREE_OPERAND (t
, 1);
6907 /* Convert A ? 1 : 0 to simply A. */
6908 if (integer_onep (TREE_OPERAND (t
, 1))
6909 && integer_zerop (TREE_OPERAND (t
, 2))
6910 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
6911 call to fold will try to move the conversion inside
6912 a COND, which will recurse. In that case, the COND_EXPR
6913 is probably the best choice, so leave it alone. */
6914 && type
== TREE_TYPE (arg0
))
6915 return pedantic_non_lvalue (arg0
);
6917 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
6918 operation is simply A & 2. */
6920 if (integer_zerop (TREE_OPERAND (t
, 2))
6921 && TREE_CODE (arg0
) == NE_EXPR
6922 && integer_zerop (TREE_OPERAND (arg0
, 1))
6923 && integer_pow2p (arg1
)
6924 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
6925 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
6927 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
6932 /* When pedantic, a compound expression can be neither an lvalue
6933 nor an integer constant expression. */
6934 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
6936 /* Don't let (0, 0) be null pointer constant. */
6937 if (integer_zerop (arg1
))
6938 return build1 (NOP_EXPR
, TREE_TYPE (arg1
), arg1
);
6943 return build_complex (type
, arg0
, arg1
);
6947 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
6949 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
6950 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
6951 TREE_OPERAND (arg0
, 1));
6952 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
6953 return TREE_REALPART (arg0
);
6954 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
6955 return fold (build (TREE_CODE (arg0
), type
,
6956 fold (build1 (REALPART_EXPR
, type
,
6957 TREE_OPERAND (arg0
, 0))),
6958 fold (build1 (REALPART_EXPR
,
6959 type
, TREE_OPERAND (arg0
, 1)))));
6963 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
6964 return convert (type
, integer_zero_node
);
6965 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
6966 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
6967 TREE_OPERAND (arg0
, 0));
6968 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
6969 return TREE_IMAGPART (arg0
);
6970 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
6971 return fold (build (TREE_CODE (arg0
), type
,
6972 fold (build1 (IMAGPART_EXPR
, type
,
6973 TREE_OPERAND (arg0
, 0))),
6974 fold (build1 (IMAGPART_EXPR
, type
,
6975 TREE_OPERAND (arg0
, 1)))));
6978 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
6980 case CLEANUP_POINT_EXPR
:
6981 if (! has_cleanups (arg0
))
6982 return TREE_OPERAND (t
, 0);
6985 enum tree_code code0
= TREE_CODE (arg0
);
6986 int kind0
= TREE_CODE_CLASS (code0
);
6987 tree arg00
= TREE_OPERAND (arg0
, 0);
6990 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
6991 return fold (build1 (code0
, type
,
6992 fold (build1 (CLEANUP_POINT_EXPR
,
6993 TREE_TYPE (arg00
), arg00
))));
6995 if (kind0
== '<' || kind0
== '2'
6996 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
6997 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
6998 || code0
== TRUTH_XOR_EXPR
)
7000 arg01
= TREE_OPERAND (arg0
, 1);
7002 if (TREE_CONSTANT (arg00
)
7003 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7004 && ! has_cleanups (arg00
)))
7005 return fold (build (code0
, type
, arg00
,
7006 fold (build1 (CLEANUP_POINT_EXPR
,
7007 TREE_TYPE (arg01
), arg01
))));
7009 if (TREE_CONSTANT (arg01
))
7010 return fold (build (code0
, type
,
7011 fold (build1 (CLEANUP_POINT_EXPR
,
7012 TREE_TYPE (arg00
), arg00
)),
7021 } /* switch (code) */
7024 /* Determine if first argument is a multiple of second argument. Return 0 if
7025 it is not, or we cannot easily determined it to be.
7027 An example of the sort of thing we care about (at this point; this routine
7028 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7029 fold cases do now) is discovering that
7031 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7037 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7039 This code also handles discovering that
7041 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7043 is a multiple of 8 so we don't have to worry about dealing with a
7046 Note that we *look* inside a SAVE_EXPR only to determine how it was
7047 calculated; it is not safe for fold to do much of anything else with the
7048 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7049 at run time. For example, the latter example above *cannot* be implemented
7050 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7051 evaluation time of the original SAVE_EXPR is not necessarily the same at
7052 the time the new expression is evaluated. The only optimization of this
7053 sort that would be valid is changing
7055 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7059 SAVE_EXPR (I) * SAVE_EXPR (J)
7061 (where the same SAVE_EXPR (J) is used in the original and the
7062 transformed version). */
7065 multiple_of_p (type
, top
, bottom
)
7070 if (operand_equal_p (top
, bottom
, 0))
7073 if (TREE_CODE (type
) != INTEGER_TYPE
)
7076 switch (TREE_CODE (top
))
7079 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7080 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7084 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7085 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7088 /* Can't handle conversions from non-integral or wider integral type. */
7089 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7090 || (TYPE_PRECISION (type
)
7091 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7094 /* .. fall through ... */
7097 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7100 if ((TREE_CODE (bottom
) != INTEGER_CST
)
7101 || (tree_int_cst_sgn (top
) < 0)
7102 || (tree_int_cst_sgn (bottom
) < 0))
7104 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,