1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
60 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
61 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
62 static bool negate_expr_p (tree
);
63 static tree
negate_expr (tree
);
64 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
65 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
66 static tree
int_const_binop (enum tree_code
, tree
, tree
, int);
67 static tree
const_binop (enum tree_code
, tree
, tree
, int);
68 static hashval_t
size_htab_hash (const void *);
69 static int size_htab_eq (const void *, const void *);
70 static tree
fold_convert (tree
, tree
);
71 static enum tree_code
invert_tree_comparison (enum tree_code
);
72 static enum tree_code
swap_tree_comparison (enum tree_code
);
73 static int comparison_to_compcode (enum tree_code
);
74 static enum tree_code
compcode_to_comparison (int);
75 static int truth_value_p (enum tree_code
);
76 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
77 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
78 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
79 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
80 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
81 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
82 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
83 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
84 enum machine_mode
*, int *, int *,
86 static int all_ones_mask_p (tree
, int);
87 static tree
sign_bit_p (tree
, tree
);
88 static int simple_operand_p (tree
);
89 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
90 static tree
make_range (tree
, int *, tree
*, tree
*);
91 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
92 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
94 static tree
fold_range_test (tree
);
95 static tree
unextend (tree
, int, int, tree
);
96 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
97 static tree
optimize_minmax_comparison (tree
);
98 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
);
99 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
);
100 static tree
strip_compound_expr (tree
, tree
);
101 static int multiple_of_p (tree
, tree
, tree
);
102 static tree
constant_boolean_node (int, tree
);
103 static int count_cond (tree
, int);
104 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
, tree
,
106 static bool fold_real_zero_addition_p (tree
, tree
, int);
107 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
109 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
111 /* The following constants represent a bit based encoding of GCC's
112 comparison operators. This encoding simplifies transformations
113 on relational comparison operators, such as AND and OR. */
114 #define COMPCODE_FALSE 0
115 #define COMPCODE_LT 1
116 #define COMPCODE_EQ 2
117 #define COMPCODE_LE 3
118 #define COMPCODE_GT 4
119 #define COMPCODE_NE 5
120 #define COMPCODE_GE 6
121 #define COMPCODE_TRUE 7
123 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
124 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
125 and SUM1. Then this yields nonzero if overflow occurred during the
128 Overflow occurs if A and B have the same sign, but A and SUM differ in
129 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
131 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
133 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
134 We do that by representing the two-word integer in 4 words, with only
135 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
136 number. The value of the word is LOWPART + HIGHPART * BASE. */
139 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
140 #define HIGHPART(x) \
141 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
142 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
144 /* Unpack a two-word integer into 4 words.
145 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
146 WORDS points to the array of HOST_WIDE_INTs. */
149 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
151 words
[0] = LOWPART (low
);
152 words
[1] = HIGHPART (low
);
153 words
[2] = LOWPART (hi
);
154 words
[3] = HIGHPART (hi
);
157 /* Pack an array of 4 words into a two-word integer.
158 WORDS points to the array of words.
159 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
162 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
, HOST_WIDE_INT
*hi
)
164 *low
= words
[0] + words
[1] * BASE
;
165 *hi
= words
[2] + words
[3] * BASE
;
168 /* Make the integer constant T valid for its type by setting to 0 or 1 all
169 the bits in the constant that don't belong in the type.
171 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
172 nonzero, a signed overflow has already occurred in calculating T, so
176 force_fit_type (tree t
, int overflow
)
178 unsigned HOST_WIDE_INT low
;
182 if (TREE_CODE (t
) == REAL_CST
)
184 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
185 Consider doing it via real_convert now. */
189 else if (TREE_CODE (t
) != INTEGER_CST
)
192 low
= TREE_INT_CST_LOW (t
);
193 high
= TREE_INT_CST_HIGH (t
);
195 if (POINTER_TYPE_P (TREE_TYPE (t
)))
198 prec
= TYPE_PRECISION (TREE_TYPE (t
));
200 /* First clear all bits that are beyond the type's precision. */
202 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
204 else if (prec
> HOST_BITS_PER_WIDE_INT
)
205 TREE_INT_CST_HIGH (t
)
206 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
209 TREE_INT_CST_HIGH (t
) = 0;
210 if (prec
< HOST_BITS_PER_WIDE_INT
)
211 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
214 /* Unsigned types do not suffer sign extension or overflow unless they
216 if (TREE_UNSIGNED (TREE_TYPE (t
))
217 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
218 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
221 /* If the value's sign bit is set, extend the sign. */
222 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
223 && (prec
> HOST_BITS_PER_WIDE_INT
224 ? 0 != (TREE_INT_CST_HIGH (t
)
226 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
227 : 0 != (TREE_INT_CST_LOW (t
)
228 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
230 /* Value is negative:
231 set to 1 all the bits that are outside this type's precision. */
232 if (prec
> HOST_BITS_PER_WIDE_INT
)
233 TREE_INT_CST_HIGH (t
)
234 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
237 TREE_INT_CST_HIGH (t
) = -1;
238 if (prec
< HOST_BITS_PER_WIDE_INT
)
239 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
243 /* Return nonzero if signed overflow occurred. */
245 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
249 /* Add two doubleword integers with doubleword result.
250 Each argument is given as two `HOST_WIDE_INT' pieces.
251 One argument is L1 and H1; the other, L2 and H2.
252 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
255 add_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, unsigned HOST_WIDE_INT l2
,
256 HOST_WIDE_INT h2
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
258 unsigned HOST_WIDE_INT l
;
262 h
= h1
+ h2
+ (l
< l1
);
266 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
269 /* Negate a doubleword integer with doubleword result.
270 Return nonzero if the operation overflows, assuming it's signed.
271 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
272 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
275 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, unsigned HOST_WIDE_INT
*lv
,
282 return (*hv
& h1
) < 0;
292 /* Multiply two doubleword integers with doubleword result.
293 Return nonzero if the operation overflows, assuming it's signed.
294 Each argument is given as two `HOST_WIDE_INT' pieces.
295 One argument is L1 and H1; the other, L2 and H2.
296 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
299 mul_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, unsigned HOST_WIDE_INT l2
,
300 HOST_WIDE_INT h2
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
302 HOST_WIDE_INT arg1
[4];
303 HOST_WIDE_INT arg2
[4];
304 HOST_WIDE_INT prod
[4 * 2];
305 unsigned HOST_WIDE_INT carry
;
307 unsigned HOST_WIDE_INT toplow
, neglow
;
308 HOST_WIDE_INT tophigh
, neghigh
;
310 encode (arg1
, l1
, h1
);
311 encode (arg2
, l2
, h2
);
313 memset ((char *) prod
, 0, sizeof prod
);
315 for (i
= 0; i
< 4; i
++)
318 for (j
= 0; j
< 4; j
++)
321 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
322 carry
+= arg1
[i
] * arg2
[j
];
323 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
325 prod
[k
] = LOWPART (carry
);
326 carry
= HIGHPART (carry
);
331 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
333 /* Check for overflow by calculating the top half of the answer in full;
334 it should agree with the low half's sign bit. */
335 decode (prod
+ 4, &toplow
, &tophigh
);
338 neg_double (l2
, h2
, &neglow
, &neghigh
);
339 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
343 neg_double (l1
, h1
, &neglow
, &neghigh
);
344 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
346 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
349 /* Shift the doubleword integer in L1, H1 left by COUNT places
350 keeping only PREC bits of result.
351 Shift right if COUNT is negative.
352 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
353 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
356 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, HOST_WIDE_INT count
,
357 unsigned int prec
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
360 unsigned HOST_WIDE_INT signmask
;
364 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
368 #ifdef SHIFT_COUNT_TRUNCATED
369 if (SHIFT_COUNT_TRUNCATED
)
373 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
375 /* Shifting by the host word size is undefined according to the
376 ANSI standard, so we must handle this as a special case. */
380 else if (count
>= HOST_BITS_PER_WIDE_INT
)
382 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
387 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
388 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
392 /* Sign extend all bits that are beyond the precision. */
394 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
395 ? ((unsigned HOST_WIDE_INT
) *hv
396 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
397 : (*lv
>> (prec
- 1))) & 1);
399 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
401 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
403 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
404 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
409 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
410 *lv
|= signmask
<< prec
;
414 /* Shift the doubleword integer in L1, H1 right by COUNT places
415 keeping only PREC bits of result. COUNT must be positive.
416 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
417 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
420 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, HOST_WIDE_INT count
,
421 unsigned int prec
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
424 unsigned HOST_WIDE_INT signmask
;
427 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
430 #ifdef SHIFT_COUNT_TRUNCATED
431 if (SHIFT_COUNT_TRUNCATED
)
435 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
437 /* Shifting by the host word size is undefined according to the
438 ANSI standard, so we must handle this as a special case. */
442 else if (count
>= HOST_BITS_PER_WIDE_INT
)
445 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
449 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
451 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
454 /* Zero / sign extend all bits that are beyond the precision. */
456 if (count
>= (HOST_WIDE_INT
)prec
)
461 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
463 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
465 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
466 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
471 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
472 *lv
|= signmask
<< (prec
- count
);
476 /* Rotate the doubleword integer in L1, H1 left by COUNT places
477 keeping only PREC bits of result.
478 Rotate right if COUNT is negative.
479 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
482 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, HOST_WIDE_INT count
,
483 unsigned int prec
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
485 unsigned HOST_WIDE_INT s1l
, s2l
;
486 HOST_WIDE_INT s1h
, s2h
;
492 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
493 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
498 /* Rotate the doubleword integer in L1, H1 left by COUNT places
499 keeping only PREC bits of result. COUNT must be positive.
500 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
503 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
, HOST_WIDE_INT count
,
504 unsigned int prec
, unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
506 unsigned HOST_WIDE_INT s1l
, s2l
;
507 HOST_WIDE_INT s1h
, s2h
;
513 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
514 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
519 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
520 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
521 CODE is a tree code for a kind of division, one of
522 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
524 It controls how the quotient is rounded to an integer.
525 Return nonzero if the operation overflows.
526 UNS nonzero says do unsigned division. */
529 div_and_round_double (enum tree_code code
, int uns
,
530 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
531 HOST_WIDE_INT hnum_orig
,
532 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
533 HOST_WIDE_INT hden_orig
, unsigned HOST_WIDE_INT
*lquo
,
534 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
538 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
539 HOST_WIDE_INT den
[4], quo
[4];
541 unsigned HOST_WIDE_INT work
;
542 unsigned HOST_WIDE_INT carry
= 0;
543 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
544 HOST_WIDE_INT hnum
= hnum_orig
;
545 unsigned HOST_WIDE_INT lden
= lden_orig
;
546 HOST_WIDE_INT hden
= hden_orig
;
549 if (hden
== 0 && lden
== 0)
550 overflow
= 1, lden
= 1;
552 /* calculate quotient sign and convert operands to unsigned. */
558 /* (minimum integer) / (-1) is the only overflow case. */
559 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
560 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
566 neg_double (lden
, hden
, &lden
, &hden
);
570 if (hnum
== 0 && hden
== 0)
571 { /* single precision */
573 /* This unsigned division rounds toward zero. */
579 { /* trivial case: dividend < divisor */
580 /* hden != 0 already checked. */
587 memset ((char *) quo
, 0, sizeof quo
);
589 memset ((char *) num
, 0, sizeof num
); /* to zero 9th element */
590 memset ((char *) den
, 0, sizeof den
);
592 encode (num
, lnum
, hnum
);
593 encode (den
, lden
, hden
);
595 /* Special code for when the divisor < BASE. */
596 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
598 /* hnum != 0 already checked. */
599 for (i
= 4 - 1; i
>= 0; i
--)
601 work
= num
[i
] + carry
* BASE
;
602 quo
[i
] = work
/ lden
;
608 /* Full double precision division,
609 with thanks to Don Knuth's "Seminumerical Algorithms". */
610 int num_hi_sig
, den_hi_sig
;
611 unsigned HOST_WIDE_INT quo_est
, scale
;
613 /* Find the highest nonzero divisor digit. */
614 for (i
= 4 - 1;; i
--)
621 /* Insure that the first digit of the divisor is at least BASE/2.
622 This is required by the quotient digit estimation algorithm. */
624 scale
= BASE
/ (den
[den_hi_sig
] + 1);
626 { /* scale divisor and dividend */
628 for (i
= 0; i
<= 4 - 1; i
++)
630 work
= (num
[i
] * scale
) + carry
;
631 num
[i
] = LOWPART (work
);
632 carry
= HIGHPART (work
);
637 for (i
= 0; i
<= 4 - 1; i
++)
639 work
= (den
[i
] * scale
) + carry
;
640 den
[i
] = LOWPART (work
);
641 carry
= HIGHPART (work
);
642 if (den
[i
] != 0) den_hi_sig
= i
;
649 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
651 /* Guess the next quotient digit, quo_est, by dividing the first
652 two remaining dividend digits by the high order quotient digit.
653 quo_est is never low and is at most 2 high. */
654 unsigned HOST_WIDE_INT tmp
;
656 num_hi_sig
= i
+ den_hi_sig
+ 1;
657 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
658 if (num
[num_hi_sig
] != den
[den_hi_sig
])
659 quo_est
= work
/ den
[den_hi_sig
];
663 /* Refine quo_est so it's usually correct, and at most one high. */
664 tmp
= work
- quo_est
* den
[den_hi_sig
];
666 && (den
[den_hi_sig
- 1] * quo_est
667 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
670 /* Try QUO_EST as the quotient digit, by multiplying the
671 divisor by QUO_EST and subtracting from the remaining dividend.
672 Keep in mind that QUO_EST is the I - 1st digit. */
675 for (j
= 0; j
<= den_hi_sig
; j
++)
677 work
= quo_est
* den
[j
] + carry
;
678 carry
= HIGHPART (work
);
679 work
= num
[i
+ j
] - LOWPART (work
);
680 num
[i
+ j
] = LOWPART (work
);
681 carry
+= HIGHPART (work
) != 0;
684 /* If quo_est was high by one, then num[i] went negative and
685 we need to correct things. */
686 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
689 carry
= 0; /* add divisor back in */
690 for (j
= 0; j
<= den_hi_sig
; j
++)
692 work
= num
[i
+ j
] + den
[j
] + carry
;
693 carry
= HIGHPART (work
);
694 num
[i
+ j
] = LOWPART (work
);
697 num
[num_hi_sig
] += carry
;
700 /* Store the quotient digit. */
705 decode (quo
, lquo
, hquo
);
708 /* if result is negative, make it so. */
710 neg_double (*lquo
, *hquo
, lquo
, hquo
);
712 /* compute trial remainder: rem = num - (quo * den) */
713 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
714 neg_double (*lrem
, *hrem
, lrem
, hrem
);
715 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
720 case TRUNC_MOD_EXPR
: /* round toward zero */
721 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
725 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
726 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
729 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
737 case CEIL_MOD_EXPR
: /* round toward positive infinity */
738 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
740 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
748 case ROUND_MOD_EXPR
: /* round to closest integer */
750 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
751 HOST_WIDE_INT habs_rem
= *hrem
;
752 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
753 HOST_WIDE_INT habs_den
= hden
, htwice
;
755 /* Get absolute values. */
757 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
759 neg_double (lden
, hden
, &labs_den
, &habs_den
);
761 /* If (2 * abs (lrem) >= abs (lden)) */
762 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
763 labs_rem
, habs_rem
, <wice
, &htwice
);
765 if (((unsigned HOST_WIDE_INT
) habs_den
766 < (unsigned HOST_WIDE_INT
) htwice
)
767 || (((unsigned HOST_WIDE_INT
) habs_den
768 == (unsigned HOST_WIDE_INT
) htwice
)
769 && (labs_den
< ltwice
)))
773 add_double (*lquo
, *hquo
,
774 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
777 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
789 /* compute true remainder: rem = num - (quo * den) */
790 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
791 neg_double (*lrem
, *hrem
, lrem
, hrem
);
792 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
796 /* Determine whether an expression T can be cheaply negated using
797 the function negate_expr. */
800 negate_expr_p (tree t
)
802 unsigned HOST_WIDE_INT val
;
809 type
= TREE_TYPE (t
);
812 switch (TREE_CODE (t
))
815 if (TREE_UNSIGNED (type
))
818 /* Check that -CST will not overflow type. */
819 prec
= TYPE_PRECISION (type
);
820 if (prec
> HOST_BITS_PER_WIDE_INT
)
822 if (TREE_INT_CST_LOW (t
) != 0)
824 prec
-= HOST_BITS_PER_WIDE_INT
;
825 val
= TREE_INT_CST_HIGH (t
);
828 val
= TREE_INT_CST_LOW (t
);
829 if (prec
< HOST_BITS_PER_WIDE_INT
)
830 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
831 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
844 /* Given T, an expression, return the negation of T. Allow for T to be
845 null, in which case return null. */
856 type
= TREE_TYPE (t
);
859 switch (TREE_CODE (t
))
863 if (! TREE_UNSIGNED (type
)
864 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
865 && ! TREE_OVERFLOW (tem
))
870 return convert (type
, TREE_OPERAND (t
, 0));
873 /* - (A - B) -> B - A */
874 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
875 return convert (type
,
876 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
878 TREE_OPERAND (t
, 0))));
885 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
888 /* Split a tree IN into a constant, literal and variable parts that could be
889 combined with CODE to make IN. "constant" means an expression with
890 TREE_CONSTANT but that isn't an actual constant. CODE must be a
891 commutative arithmetic operation. Store the constant part into *CONP,
892 the literal in *LITP and return the variable part. If a part isn't
893 present, set it to null. If the tree does not decompose in this way,
894 return the entire tree as the variable part and the other parts as null.
896 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
897 case, we negate an operand that was subtracted. Except if it is a
898 literal for which we use *MINUS_LITP instead.
900 If NEGATE_P is true, we are negating all of IN, again except a literal
901 for which we use *MINUS_LITP instead.
903 If IN is itself a literal or constant, return it as appropriate.
905 Note that we do not guarantee that any of the three values will be the
906 same type as IN, but they will have the same signedness and mode. */
909 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
, tree
*minus_litp
, int negate_p
)
917 /* Strip any conversions that don't change the machine mode or signedness. */
918 STRIP_SIGN_NOPS (in
);
920 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
922 else if (TREE_CODE (in
) == code
923 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
924 /* We can associate addition and subtraction together (even
925 though the C standard doesn't say so) for integers because
926 the value is not affected. For reals, the value might be
927 affected, so we can't. */
928 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
929 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
931 tree op0
= TREE_OPERAND (in
, 0);
932 tree op1
= TREE_OPERAND (in
, 1);
933 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
934 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
936 /* First see if either of the operands is a literal, then a constant. */
937 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
938 *litp
= op0
, op0
= 0;
939 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
940 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
942 if (op0
!= 0 && TREE_CONSTANT (op0
))
943 *conp
= op0
, op0
= 0;
944 else if (op1
!= 0 && TREE_CONSTANT (op1
))
945 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
947 /* If we haven't dealt with either operand, this is not a case we can
948 decompose. Otherwise, VAR is either of the ones remaining, if any. */
949 if (op0
!= 0 && op1
!= 0)
954 var
= op1
, neg_var_p
= neg1_p
;
956 /* Now do any needed negations. */
958 *minus_litp
= *litp
, *litp
= 0;
960 *conp
= negate_expr (*conp
);
962 var
= negate_expr (var
);
964 else if (TREE_CONSTANT (in
))
972 *minus_litp
= *litp
, *litp
= 0;
973 else if (*minus_litp
)
974 *litp
= *minus_litp
, *minus_litp
= 0;
975 *conp
= negate_expr (*conp
);
976 var
= negate_expr (var
);
982 /* Re-associate trees split by the above function. T1 and T2 are either
983 expressions to associate or null. Return the new expression, if any. If
984 we build an operation, do it in TYPE and with CODE. */
987 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
994 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
995 try to fold this since we will have infinite recursion. But do
996 deal with any NEGATE_EXPRs. */
997 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
998 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1000 if (code
== PLUS_EXPR
)
1002 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1003 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1004 convert (type
, TREE_OPERAND (t1
, 0)));
1005 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1006 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1007 convert (type
, TREE_OPERAND (t2
, 0)));
1009 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1012 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1015 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1016 to produce a new constant.
1018 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1021 int_const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1023 unsigned HOST_WIDE_INT int1l
, int2l
;
1024 HOST_WIDE_INT int1h
, int2h
;
1025 unsigned HOST_WIDE_INT low
;
1027 unsigned HOST_WIDE_INT garbagel
;
1028 HOST_WIDE_INT garbageh
;
1030 tree type
= TREE_TYPE (arg1
);
1031 int uns
= TREE_UNSIGNED (type
);
1033 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1035 int no_overflow
= 0;
1037 int1l
= TREE_INT_CST_LOW (arg1
);
1038 int1h
= TREE_INT_CST_HIGH (arg1
);
1039 int2l
= TREE_INT_CST_LOW (arg2
);
1040 int2h
= TREE_INT_CST_HIGH (arg2
);
1045 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1049 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1053 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1056 case BIT_ANDTC_EXPR
:
1057 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1063 /* It's unclear from the C standard whether shifts can overflow.
1064 The following code ignores overflow; perhaps a C standard
1065 interpretation ruling is needed. */
1066 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1074 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1079 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1083 neg_double (int2l
, int2h
, &low
, &hi
);
1084 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1085 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1089 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1092 case TRUNC_DIV_EXPR
:
1093 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1094 case EXACT_DIV_EXPR
:
1095 /* This is a shortcut for a common special case. */
1096 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1097 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1098 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1099 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1101 if (code
== CEIL_DIV_EXPR
)
1104 low
= int1l
/ int2l
, hi
= 0;
1108 /* ... fall through ... */
1110 case ROUND_DIV_EXPR
:
1111 if (int2h
== 0 && int2l
== 1)
1113 low
= int1l
, hi
= int1h
;
1116 if (int1l
== int2l
&& int1h
== int2h
1117 && ! (int1l
== 0 && int1h
== 0))
1122 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1123 &low
, &hi
, &garbagel
, &garbageh
);
1126 case TRUNC_MOD_EXPR
:
1127 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1128 /* This is a shortcut for a common special case. */
1129 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1130 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1131 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1132 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1134 if (code
== CEIL_MOD_EXPR
)
1136 low
= int1l
% int2l
, hi
= 0;
1140 /* ... fall through ... */
1142 case ROUND_MOD_EXPR
:
1143 overflow
= div_and_round_double (code
, uns
,
1144 int1l
, int1h
, int2l
, int2h
,
1145 &garbagel
, &garbageh
, &low
, &hi
);
1151 low
= (((unsigned HOST_WIDE_INT
) int1h
1152 < (unsigned HOST_WIDE_INT
) int2h
)
1153 || (((unsigned HOST_WIDE_INT
) int1h
1154 == (unsigned HOST_WIDE_INT
) int2h
)
1157 low
= (int1h
< int2h
1158 || (int1h
== int2h
&& int1l
< int2l
));
1160 if (low
== (code
== MIN_EXPR
))
1161 low
= int1l
, hi
= int1h
;
1163 low
= int2l
, hi
= int2h
;
1170 /* If this is for a sizetype, can be represented as one (signed)
1171 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1174 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1175 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1176 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1177 return size_int_type_wide (low
, type
);
1180 t
= build_int_2 (low
, hi
);
1181 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1186 ? (!uns
|| is_sizetype
) && overflow
1187 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1189 | TREE_OVERFLOW (arg1
)
1190 | TREE_OVERFLOW (arg2
));
1192 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1193 So check if force_fit_type truncated the value. */
1195 && ! TREE_OVERFLOW (t
)
1196 && (TREE_INT_CST_HIGH (t
) != hi
1197 || TREE_INT_CST_LOW (t
) != low
))
1198 TREE_OVERFLOW (t
) = 1;
1200 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1201 | TREE_CONSTANT_OVERFLOW (arg1
)
1202 | TREE_CONSTANT_OVERFLOW (arg2
));
1206 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1207 constant. We assume ARG1 and ARG2 have the same data type, or at least
1208 are the same kind of constant and the same machine mode.
1210 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1213 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1218 if (TREE_CODE (arg1
) == INTEGER_CST
)
1219 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1221 if (TREE_CODE (arg1
) == REAL_CST
)
1225 REAL_VALUE_TYPE value
;
1228 d1
= TREE_REAL_CST (arg1
);
1229 d2
= TREE_REAL_CST (arg2
);
1231 /* If either operand is a NaN, just return it. Otherwise, set up
1232 for floating-point trap; we return an overflow. */
1233 if (REAL_VALUE_ISNAN (d1
))
1235 else if (REAL_VALUE_ISNAN (d2
))
1238 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1240 t
= build_real (TREE_TYPE (arg1
),
1241 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1
)),
1245 = (force_fit_type (t
, 0)
1246 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1247 TREE_CONSTANT_OVERFLOW (t
)
1249 | TREE_CONSTANT_OVERFLOW (arg1
)
1250 | TREE_CONSTANT_OVERFLOW (arg2
);
1253 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1255 tree type
= TREE_TYPE (arg1
);
1256 tree r1
= TREE_REALPART (arg1
);
1257 tree i1
= TREE_IMAGPART (arg1
);
1258 tree r2
= TREE_REALPART (arg2
);
1259 tree i2
= TREE_IMAGPART (arg2
);
1265 t
= build_complex (type
,
1266 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1267 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1271 t
= build_complex (type
,
1272 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1273 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1277 t
= build_complex (type
,
1278 const_binop (MINUS_EXPR
,
1279 const_binop (MULT_EXPR
,
1281 const_binop (MULT_EXPR
,
1284 const_binop (PLUS_EXPR
,
1285 const_binop (MULT_EXPR
,
1287 const_binop (MULT_EXPR
,
1295 = const_binop (PLUS_EXPR
,
1296 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1297 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1300 t
= build_complex (type
,
1302 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1303 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1304 const_binop (PLUS_EXPR
,
1305 const_binop (MULT_EXPR
, r1
, r2
,
1307 const_binop (MULT_EXPR
, i1
, i2
,
1310 magsquared
, notrunc
),
1312 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1313 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1314 const_binop (MINUS_EXPR
,
1315 const_binop (MULT_EXPR
, i1
, r2
,
1317 const_binop (MULT_EXPR
, r1
, i2
,
1320 magsquared
, notrunc
));
1332 /* These are the hash table functions for the hash table of INTEGER_CST
1333 nodes of a sizetype. */
1335 /* Return the hash code code X, an INTEGER_CST. */
1338 size_htab_hash (const void *x
)
1342 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1343 ^ htab_hash_pointer (TREE_TYPE (t
))
1344 ^ (TREE_OVERFLOW (t
) << 20));
1347 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1348 is the same as that given by *Y, which is the same. */
1351 size_htab_eq (const void *x
, const void *y
)
1356 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1357 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1358 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1359 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1362 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1363 bits are given by NUMBER and of the sizetype represented by KIND. */
1366 size_int_wide (HOST_WIDE_INT number
, enum size_type_kind kind
)
1368 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1371 /* Likewise, but the desired type is specified explicitly. */
1373 static GTY (()) tree new_const
;
1374 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1378 size_int_type_wide (HOST_WIDE_INT number
, tree type
)
1384 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1385 new_const
= make_node (INTEGER_CST
);
1388 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1389 hash table, we return the value from the hash table. Otherwise, we
1390 place that in the hash table and make a new node for the next time. */
1391 TREE_INT_CST_LOW (new_const
) = number
;
1392 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1393 TREE_TYPE (new_const
) = type
;
1394 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1395 = force_fit_type (new_const
, 0);
1397 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1403 new_const
= make_node (INTEGER_CST
);
1407 return (tree
) *slot
;
1410 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1411 is a tree code. The type of the result is taken from the operands.
1412 Both must be the same type integer type and it must be a size type.
1413 If the operands are constant, so is the result. */
1416 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
1418 tree type
= TREE_TYPE (arg0
);
1420 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1421 || type
!= TREE_TYPE (arg1
))
1424 /* Handle the special case of two integer constants faster. */
1425 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1427 /* And some specific cases even faster than that. */
1428 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1430 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1431 && integer_zerop (arg1
))
1433 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1436 /* Handle general case of two integer constants. */
1437 return int_const_binop (code
, arg0
, arg1
, 0);
1440 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1441 return error_mark_node
;
1443 return fold (build (code
, type
, arg0
, arg1
));
1446 /* Given two values, either both of sizetype or both of bitsizetype,
1447 compute the difference between the two values. Return the value
1448 in signed type corresponding to the type of the operands. */
1451 size_diffop (tree arg0
, tree arg1
)
1453 tree type
= TREE_TYPE (arg0
);
1456 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1457 || type
!= TREE_TYPE (arg1
))
1460 /* If the type is already signed, just do the simple thing. */
1461 if (! TREE_UNSIGNED (type
))
1462 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1464 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
1465 ? sbitsizetype
: ssizetype
);
1467 /* If either operand is not a constant, do the conversions to the signed
1468 type and subtract. The hardware will do the right thing with any
1469 overflow in the subtraction. */
1470 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1471 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
1472 convert (ctype
, arg1
));
1474 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1475 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1476 overflow) and negate (which can't either). Special-case a result
1477 of zero while we're here. */
1478 if (tree_int_cst_equal (arg0
, arg1
))
1479 return convert (ctype
, integer_zero_node
);
1480 else if (tree_int_cst_lt (arg1
, arg0
))
1481 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1483 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
1484 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
1488 /* Given T, a tree representing type conversion of ARG1, a constant,
1489 return a constant tree representing the result of conversion. */
1492 fold_convert (tree t
, tree arg1
)
1494 tree type
= TREE_TYPE (t
);
1497 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1499 if (TREE_CODE (arg1
) == INTEGER_CST
)
1501 /* If we would build a constant wider than GCC supports,
1502 leave the conversion unfolded. */
1503 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1506 /* If we are trying to make a sizetype for a small integer, use
1507 size_int to pick up cached types to reduce duplicate nodes. */
1508 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1509 && !TREE_CONSTANT_OVERFLOW (arg1
)
1510 && compare_tree_int (arg1
, 10000) < 0)
1511 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1513 /* Given an integer constant, make new constant with new type,
1514 appropriately sign-extended or truncated. */
1515 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1516 TREE_INT_CST_HIGH (arg1
));
1517 TREE_TYPE (t
) = type
;
1518 /* Indicate an overflow if (1) ARG1 already overflowed,
1519 or (2) force_fit_type indicates an overflow.
1520 Tell force_fit_type that an overflow has already occurred
1521 if ARG1 is a too-large unsigned value and T is signed.
1522 But don't indicate an overflow if converting a pointer. */
1524 = ((force_fit_type (t
,
1525 (TREE_INT_CST_HIGH (arg1
) < 0
1526 && (TREE_UNSIGNED (type
)
1527 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1528 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1529 || TREE_OVERFLOW (arg1
));
1530 TREE_CONSTANT_OVERFLOW (t
)
1531 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1533 else if (TREE_CODE (arg1
) == REAL_CST
)
1535 /* Don't initialize these, use assignments.
1536 Initialized local aggregates don't work on old compilers. */
1540 tree type1
= TREE_TYPE (arg1
);
1543 x
= TREE_REAL_CST (arg1
);
1544 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1546 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1547 if (!no_upper_bound
)
1548 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1550 /* See if X will be in range after truncation towards 0.
1551 To compensate for truncation, move the bounds away from 0,
1552 but reject if X exactly equals the adjusted bounds. */
1553 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1554 if (!no_upper_bound
)
1555 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1556 /* If X is a NaN, use zero instead and show we have an overflow.
1557 Otherwise, range check. */
1558 if (REAL_VALUE_ISNAN (x
))
1559 overflow
= 1, x
= dconst0
;
1560 else if (! (REAL_VALUES_LESS (l
, x
)
1562 && REAL_VALUES_LESS (x
, u
)))
1566 HOST_WIDE_INT low
, high
;
1567 REAL_VALUE_TO_INT (&low
, &high
, x
);
1568 t
= build_int_2 (low
, high
);
1570 TREE_TYPE (t
) = type
;
1572 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1573 TREE_CONSTANT_OVERFLOW (t
)
1574 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1576 TREE_TYPE (t
) = type
;
1578 else if (TREE_CODE (type
) == REAL_TYPE
)
1580 if (TREE_CODE (arg1
) == INTEGER_CST
)
1581 return build_real_from_int_cst (type
, arg1
);
1582 if (TREE_CODE (arg1
) == REAL_CST
)
1584 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1586 /* We make a copy of ARG1 so that we don't modify an
1587 existing constant tree. */
1588 t
= copy_node (arg1
);
1589 TREE_TYPE (t
) = type
;
1593 t
= build_real (type
,
1594 real_value_truncate (TYPE_MODE (type
),
1595 TREE_REAL_CST (arg1
)));
1598 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1599 TREE_CONSTANT_OVERFLOW (t
)
1600 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1604 TREE_CONSTANT (t
) = 1;
1608 /* Return an expr equal to X but certainly not valid as an lvalue. */
1615 /* These things are certainly not lvalues. */
1616 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1617 || TREE_CODE (x
) == INTEGER_CST
1618 || TREE_CODE (x
) == REAL_CST
1619 || TREE_CODE (x
) == STRING_CST
1620 || TREE_CODE (x
) == ADDR_EXPR
)
1623 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1624 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1628 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1629 Zero means allow extended lvalues. */
1631 int pedantic_lvalues
;
1633 /* When pedantic, return an expr equal to X but certainly not valid as a
1634 pedantic lvalue. Otherwise, return X. */
1637 pedantic_non_lvalue (tree x
)
1639 if (pedantic_lvalues
)
1640 return non_lvalue (x
);
1645 /* Given a tree comparison code, return the code that is the logical inverse
1646 of the given code. It is not safe to do this for floating-point
1647 comparisons, except for NE_EXPR and EQ_EXPR. */
1649 static enum tree_code
1650 invert_tree_comparison (enum tree_code code
)
1671 /* Similar, but return the comparison that results if the operands are
1672 swapped. This is safe for floating-point. */
1674 static enum tree_code
1675 swap_tree_comparison (enum tree_code code
)
1696 /* Convert a comparison tree code from an enum tree_code representation
1697 into a compcode bit-based encoding. This function is the inverse of
1698 compcode_to_comparison. */
1701 comparison_to_compcode (enum tree_code code
)
1722 /* Convert a compcode bit-based encoding of a comparison operator back
1723 to GCC's enum tree_code representation. This function is the
1724 inverse of comparison_to_compcode. */
1726 static enum tree_code
1727 compcode_to_comparison (int code
)
1748 /* Return nonzero if CODE is a tree code that represents a truth value. */
1751 truth_value_p (enum tree_code code
)
1753 return (TREE_CODE_CLASS (code
) == '<'
1754 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
1755 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
1756 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
1759 /* Return nonzero if two operands are necessarily equal.
1760 If ONLY_CONST is nonzero, only return nonzero for constants.
1761 This function tests whether the operands are indistinguishable;
1762 it does not test whether they are equal using C's == operation.
1763 The distinction is important for IEEE floating point, because
1764 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1765 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1768 operand_equal_p (tree arg0
, tree arg1
, int only_const
)
1770 /* If both types don't have the same signedness, then we can't consider
1771 them equal. We must check this before the STRIP_NOPS calls
1772 because they may change the signedness of the arguments. */
1773 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
1779 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
1780 /* This is needed for conversions and for COMPONENT_REF.
1781 Might as well play it safe and always test this. */
1782 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
1783 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
1784 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
1787 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1788 We don't care about side effects in that case because the SAVE_EXPR
1789 takes care of that for us. In all other cases, two expressions are
1790 equal if they have no side effects. If we have two identical
1791 expressions with side effects that should be treated the same due
1792 to the only side effects being identical SAVE_EXPR's, that will
1793 be detected in the recursive calls below. */
1794 if (arg0
== arg1
&& ! only_const
1795 && (TREE_CODE (arg0
) == SAVE_EXPR
1796 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
1799 /* Next handle constant cases, those for which we can return 1 even
1800 if ONLY_CONST is set. */
1801 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
1802 switch (TREE_CODE (arg0
))
1805 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1806 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1807 && tree_int_cst_equal (arg0
, arg1
));
1810 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1811 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1812 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
1813 TREE_REAL_CST (arg1
)));
1819 if (TREE_CONSTANT_OVERFLOW (arg0
)
1820 || TREE_CONSTANT_OVERFLOW (arg1
))
1823 v1
= TREE_VECTOR_CST_ELTS (arg0
);
1824 v2
= TREE_VECTOR_CST_ELTS (arg1
);
1827 if (!operand_equal_p (v1
, v2
, only_const
))
1829 v1
= TREE_CHAIN (v1
);
1830 v2
= TREE_CHAIN (v2
);
1837 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
1839 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
1843 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
1844 && ! memcmp (TREE_STRING_POINTER (arg0
),
1845 TREE_STRING_POINTER (arg1
),
1846 TREE_STRING_LENGTH (arg0
)));
1849 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
1858 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
1861 /* Two conversions are equal only if signedness and modes match. */
1862 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
1863 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
1864 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
1867 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1868 TREE_OPERAND (arg1
, 0), 0);
1872 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
1873 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
1877 /* For commutative ops, allow the other order. */
1878 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
1879 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
1880 || TREE_CODE (arg0
) == BIT_IOR_EXPR
1881 || TREE_CODE (arg0
) == BIT_XOR_EXPR
1882 || TREE_CODE (arg0
) == BIT_AND_EXPR
1883 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
1884 && operand_equal_p (TREE_OPERAND (arg0
, 0),
1885 TREE_OPERAND (arg1
, 1), 0)
1886 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1887 TREE_OPERAND (arg1
, 0), 0));
1890 /* If either of the pointer (or reference) expressions we are
1891 dereferencing contain a side effect, these cannot be equal. */
1892 if (TREE_SIDE_EFFECTS (arg0
)
1893 || TREE_SIDE_EFFECTS (arg1
))
1896 switch (TREE_CODE (arg0
))
1899 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1900 TREE_OPERAND (arg1
, 0), 0);
1904 case ARRAY_RANGE_REF
:
1905 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1906 TREE_OPERAND (arg1
, 0), 0)
1907 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1908 TREE_OPERAND (arg1
, 1), 0));
1911 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1912 TREE_OPERAND (arg1
, 0), 0)
1913 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1914 TREE_OPERAND (arg1
, 1), 0)
1915 && operand_equal_p (TREE_OPERAND (arg0
, 2),
1916 TREE_OPERAND (arg1
, 2), 0));
1922 switch (TREE_CODE (arg0
))
1925 case TRUTH_NOT_EXPR
:
1926 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1927 TREE_OPERAND (arg1
, 0), 0);
1930 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
1933 /* If the CALL_EXPRs call different functions, then they
1934 clearly can not be equal. */
1935 if (! operand_equal_p (TREE_OPERAND (arg0
, 0),
1936 TREE_OPERAND (arg1
, 0), 0))
1939 /* Only consider const functions equivalent. */
1940 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
1942 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
1943 if (! (flags_from_decl_or_type (fndecl
) & ECF_CONST
))
1949 /* Now see if all the arguments are the same. operand_equal_p
1950 does not handle TREE_LIST, so we walk the operands here
1951 feeding them to operand_equal_p. */
1952 arg0
= TREE_OPERAND (arg0
, 1);
1953 arg1
= TREE_OPERAND (arg1
, 1);
1954 while (arg0
&& arg1
)
1956 if (! operand_equal_p (TREE_VALUE (arg0
), TREE_VALUE (arg1
), 0))
1959 arg0
= TREE_CHAIN (arg0
);
1960 arg1
= TREE_CHAIN (arg1
);
1963 /* If we get here and both argument lists are exhausted
1964 then the CALL_EXPRs are equal. */
1965 return ! (arg0
|| arg1
);
1972 /* Consider __builtin_sqrt equal to sqrt. */
1973 return TREE_CODE (arg0
) == FUNCTION_DECL
1974 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
1975 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
1976 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
);
1983 /* Similar to operand_equal_p, but see if ARG0 might have been made by
1984 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
1986 When in doubt, return 0. */
1989 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
1991 int unsignedp1
, unsignedpo
;
1992 tree primarg0
, primarg1
, primother
;
1993 unsigned int correct_width
;
1995 if (operand_equal_p (arg0
, arg1
, 0))
1998 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
1999 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2002 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2003 and see if the inner values are the same. This removes any
2004 signedness comparison, which doesn't matter here. */
2005 primarg0
= arg0
, primarg1
= arg1
;
2006 STRIP_NOPS (primarg0
);
2007 STRIP_NOPS (primarg1
);
2008 if (operand_equal_p (primarg0
, primarg1
, 0))
2011 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2012 actual comparison operand, ARG0.
2014 First throw away any conversions to wider types
2015 already present in the operands. */
2017 primarg1
= get_narrower (arg1
, &unsignedp1
);
2018 primother
= get_narrower (other
, &unsignedpo
);
2020 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2021 if (unsignedp1
== unsignedpo
2022 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2023 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2025 tree type
= TREE_TYPE (arg0
);
2027 /* Make sure shorter operand is extended the right way
2028 to match the longer operand. */
2029 primarg1
= convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2030 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2032 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2039 /* See if ARG is an expression that is either a comparison or is performing
2040 arithmetic on comparisons. The comparisons must only be comparing
2041 two different values, which will be stored in *CVAL1 and *CVAL2; if
2042 they are nonzero it means that some operands have already been found.
2043 No variables may be used anywhere else in the expression except in the
2044 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2045 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2047 If this is true, return 1. Otherwise, return zero. */
2050 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
2052 enum tree_code code
= TREE_CODE (arg
);
2053 char class = TREE_CODE_CLASS (code
);
2055 /* We can handle some of the 'e' cases here. */
2056 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2058 else if (class == 'e'
2059 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2060 || code
== COMPOUND_EXPR
))
2063 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2064 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2066 /* If we've already found a CVAL1 or CVAL2, this expression is
2067 two complex to handle. */
2068 if (*cval1
|| *cval2
)
2078 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2081 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2082 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2083 cval1
, cval2
, save_p
));
2089 if (code
== COND_EXPR
)
2090 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2091 cval1
, cval2
, save_p
)
2092 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2093 cval1
, cval2
, save_p
)
2094 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2095 cval1
, cval2
, save_p
));
2099 /* First see if we can handle the first operand, then the second. For
2100 the second operand, we know *CVAL1 can't be zero. It must be that
2101 one side of the comparison is each of the values; test for the
2102 case where this isn't true by failing if the two operands
2105 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2106 TREE_OPERAND (arg
, 1), 0))
2110 *cval1
= TREE_OPERAND (arg
, 0);
2111 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2113 else if (*cval2
== 0)
2114 *cval2
= TREE_OPERAND (arg
, 0);
2115 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2120 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2122 else if (*cval2
== 0)
2123 *cval2
= TREE_OPERAND (arg
, 1);
2124 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2136 /* ARG is a tree that is known to contain just arithmetic operations and
2137 comparisons. Evaluate the operations in the tree substituting NEW0 for
2138 any occurrence of OLD0 as an operand of a comparison and likewise for
2142 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
2144 tree type
= TREE_TYPE (arg
);
2145 enum tree_code code
= TREE_CODE (arg
);
2146 char class = TREE_CODE_CLASS (code
);
2148 /* We can handle some of the 'e' cases here. */
2149 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2151 else if (class == 'e'
2152 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2158 return fold (build1 (code
, type
,
2159 eval_subst (TREE_OPERAND (arg
, 0),
2160 old0
, new0
, old1
, new1
)));
2163 return fold (build (code
, type
,
2164 eval_subst (TREE_OPERAND (arg
, 0),
2165 old0
, new0
, old1
, new1
),
2166 eval_subst (TREE_OPERAND (arg
, 1),
2167 old0
, new0
, old1
, new1
)));
2173 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2176 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2179 return fold (build (code
, type
,
2180 eval_subst (TREE_OPERAND (arg
, 0),
2181 old0
, new0
, old1
, new1
),
2182 eval_subst (TREE_OPERAND (arg
, 1),
2183 old0
, new0
, old1
, new1
),
2184 eval_subst (TREE_OPERAND (arg
, 2),
2185 old0
, new0
, old1
, new1
)));
2189 /* fall through - ??? */
2193 tree arg0
= TREE_OPERAND (arg
, 0);
2194 tree arg1
= TREE_OPERAND (arg
, 1);
2196 /* We need to check both for exact equality and tree equality. The
2197 former will be true if the operand has a side-effect. In that
2198 case, we know the operand occurred exactly once. */
2200 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2202 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2205 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2207 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2210 return fold (build (code
, type
, arg0
, arg1
));
2218 /* Return a tree for the case when the result of an expression is RESULT
2219 converted to TYPE and OMITTED was previously an operand of the expression
2220 but is now not needed (e.g., we folded OMITTED * 0).
2222 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2223 the conversion of RESULT to TYPE. */
2226 omit_one_operand (tree type
, tree result
, tree omitted
)
2228 tree t
= convert (type
, result
);
2230 if (TREE_SIDE_EFFECTS (omitted
))
2231 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2233 return non_lvalue (t
);
2236 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2239 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
2241 tree t
= convert (type
, result
);
2243 if (TREE_SIDE_EFFECTS (omitted
))
2244 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2246 return pedantic_non_lvalue (t
);
2249 /* Return a simplified tree node for the truth-negation of ARG. This
2250 never alters ARG itself. We assume that ARG is an operation that
2251 returns a truth value (0 or 1). */
2254 invert_truthvalue (tree arg
)
2256 tree type
= TREE_TYPE (arg
);
2257 enum tree_code code
= TREE_CODE (arg
);
2259 if (code
== ERROR_MARK
)
2262 /* If this is a comparison, we can simply invert it, except for
2263 floating-point non-equality comparisons, in which case we just
2264 enclose a TRUTH_NOT_EXPR around what we have. */
2266 if (TREE_CODE_CLASS (code
) == '<')
2268 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2269 && !flag_unsafe_math_optimizations
2272 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2274 return build (invert_tree_comparison (code
), type
,
2275 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2281 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2283 case TRUTH_AND_EXPR
:
2284 return build (TRUTH_OR_EXPR
, type
,
2285 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2286 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2289 return build (TRUTH_AND_EXPR
, type
,
2290 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2291 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2293 case TRUTH_XOR_EXPR
:
2294 /* Here we can invert either operand. We invert the first operand
2295 unless the second operand is a TRUTH_NOT_EXPR in which case our
2296 result is the XOR of the first operand with the inside of the
2297 negation of the second operand. */
2299 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2300 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2301 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2303 return build (TRUTH_XOR_EXPR
, type
,
2304 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2305 TREE_OPERAND (arg
, 1));
2307 case TRUTH_ANDIF_EXPR
:
2308 return build (TRUTH_ORIF_EXPR
, type
,
2309 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2310 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2312 case TRUTH_ORIF_EXPR
:
2313 return build (TRUTH_ANDIF_EXPR
, type
,
2314 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2315 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2317 case TRUTH_NOT_EXPR
:
2318 return TREE_OPERAND (arg
, 0);
2321 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2322 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2323 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2326 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2327 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2329 case WITH_RECORD_EXPR
:
2330 return build (WITH_RECORD_EXPR
, type
,
2331 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2332 TREE_OPERAND (arg
, 1));
2334 case NON_LVALUE_EXPR
:
2335 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2340 return build1 (TREE_CODE (arg
), type
,
2341 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2344 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2346 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2349 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2351 case CLEANUP_POINT_EXPR
:
2352 return build1 (CLEANUP_POINT_EXPR
, type
,
2353 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2358 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2360 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2363 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2364 operands are another bit-wise operation with a common input. If so,
2365 distribute the bit operations to save an operation and possibly two if
2366 constants are involved. For example, convert
2367 (A | B) & (A | C) into A | (B & C)
2368 Further simplification will occur if B and C are constants.
2370 If this optimization cannot be done, 0 will be returned. */
2373 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
2378 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2379 || TREE_CODE (arg0
) == code
2380 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2381 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2384 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2386 common
= TREE_OPERAND (arg0
, 0);
2387 left
= TREE_OPERAND (arg0
, 1);
2388 right
= TREE_OPERAND (arg1
, 1);
2390 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2392 common
= TREE_OPERAND (arg0
, 0);
2393 left
= TREE_OPERAND (arg0
, 1);
2394 right
= TREE_OPERAND (arg1
, 0);
2396 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2398 common
= TREE_OPERAND (arg0
, 1);
2399 left
= TREE_OPERAND (arg0
, 0);
2400 right
= TREE_OPERAND (arg1
, 1);
2402 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2404 common
= TREE_OPERAND (arg0
, 1);
2405 left
= TREE_OPERAND (arg0
, 0);
2406 right
= TREE_OPERAND (arg1
, 0);
2411 return fold (build (TREE_CODE (arg0
), type
, common
,
2412 fold (build (code
, type
, left
, right
))));
2415 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2416 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2419 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
, int unsignedp
)
2421 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2422 size_int (bitsize
), bitsize_int (bitpos
));
2424 TREE_UNSIGNED (result
) = unsignedp
;
2429 /* Optimize a bit-field compare.
2431 There are two cases: First is a compare against a constant and the
2432 second is a comparison of two items where the fields are at the same
2433 bit position relative to the start of a chunk (byte, halfword, word)
2434 large enough to contain it. In these cases we can avoid the shift
2435 implicit in bitfield extractions.
2437 For constants, we emit a compare of the shifted constant with the
2438 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2439 compared. For two fields at the same position, we do the ANDs with the
2440 similar mask and compare the result of the ANDs.
2442 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2443 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2444 are the left and right operands of the comparison, respectively.
2446 If the optimization described above can be done, we return the resulting
2447 tree. Otherwise we return zero. */
2450 optimize_bit_field_compare (enum tree_code code
, tree compare_type
, tree lhs
, tree rhs
)
2452 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2453 tree type
= TREE_TYPE (lhs
);
2454 tree signed_type
, unsigned_type
;
2455 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2456 enum machine_mode lmode
, rmode
, nmode
;
2457 int lunsignedp
, runsignedp
;
2458 int lvolatilep
= 0, rvolatilep
= 0;
2459 tree linner
, rinner
= NULL_TREE
;
2463 /* Get all the information about the extractions being done. If the bit size
2464 if the same as the size of the underlying object, we aren't doing an
2465 extraction at all and so can do nothing. We also don't want to
2466 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2467 then will no longer be able to replace it. */
2468 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2469 &lunsignedp
, &lvolatilep
);
2470 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2471 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2476 /* If this is not a constant, we can only do something if bit positions,
2477 sizes, and signedness are the same. */
2478 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2479 &runsignedp
, &rvolatilep
);
2481 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2482 || lunsignedp
!= runsignedp
|| offset
!= 0
2483 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2487 /* See if we can find a mode to refer to this field. We should be able to,
2488 but fail if we can't. */
2489 nmode
= get_best_mode (lbitsize
, lbitpos
,
2490 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2491 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2492 TYPE_ALIGN (TREE_TYPE (rinner
))),
2493 word_mode
, lvolatilep
|| rvolatilep
);
2494 if (nmode
== VOIDmode
)
2497 /* Set signed and unsigned types of the precision of this mode for the
2499 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2500 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2502 /* Compute the bit position and size for the new reference and our offset
2503 within it. If the new reference is the same size as the original, we
2504 won't optimize anything, so return zero. */
2505 nbitsize
= GET_MODE_BITSIZE (nmode
);
2506 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2508 if (nbitsize
== lbitsize
)
2511 if (BYTES_BIG_ENDIAN
)
2512 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2514 /* Make the mask to be used against the extracted field. */
2515 mask
= build_int_2 (~0, ~0);
2516 TREE_TYPE (mask
) = unsigned_type
;
2517 force_fit_type (mask
, 0);
2518 mask
= convert (unsigned_type
, mask
);
2519 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2520 mask
= const_binop (RSHIFT_EXPR
, mask
,
2521 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2524 /* If not comparing with constant, just rework the comparison
2526 return build (code
, compare_type
,
2527 build (BIT_AND_EXPR
, unsigned_type
,
2528 make_bit_field_ref (linner
, unsigned_type
,
2529 nbitsize
, nbitpos
, 1),
2531 build (BIT_AND_EXPR
, unsigned_type
,
2532 make_bit_field_ref (rinner
, unsigned_type
,
2533 nbitsize
, nbitpos
, 1),
2536 /* Otherwise, we are handling the constant case. See if the constant is too
2537 big for the field. Warn and return a tree of for 0 (false) if so. We do
2538 this not only for its own sake, but to avoid having to test for this
2539 error case below. If we didn't, we might generate wrong code.
2541 For unsigned fields, the constant shifted right by the field length should
2542 be all zero. For signed fields, the high-order bits should agree with
2547 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2548 convert (unsigned_type
, rhs
),
2549 size_int (lbitsize
), 0)))
2551 warning ("comparison is always %d due to width of bit-field",
2553 return convert (compare_type
,
2555 ? integer_one_node
: integer_zero_node
));
2560 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2561 size_int (lbitsize
- 1), 0);
2562 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2564 warning ("comparison is always %d due to width of bit-field",
2566 return convert (compare_type
,
2568 ? integer_one_node
: integer_zero_node
));
2572 /* Single-bit compares should always be against zero. */
2573 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2575 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2576 rhs
= convert (type
, integer_zero_node
);
2579 /* Make a new bitfield reference, shift the constant over the
2580 appropriate number of bits and mask it with the computed mask
2581 (in case this was a signed field). If we changed it, make a new one. */
2582 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2585 TREE_SIDE_EFFECTS (lhs
) = 1;
2586 TREE_THIS_VOLATILE (lhs
) = 1;
2589 rhs
= fold (const_binop (BIT_AND_EXPR
,
2590 const_binop (LSHIFT_EXPR
,
2591 convert (unsigned_type
, rhs
),
2592 size_int (lbitpos
), 0),
2595 return build (code
, compare_type
,
2596 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2600 /* Subroutine for fold_truthop: decode a field reference.
2602 If EXP is a comparison reference, we return the innermost reference.
2604 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2605 set to the starting bit number.
2607 If the innermost field can be completely contained in a mode-sized
2608 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2610 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2611 otherwise it is not changed.
2613 *PUNSIGNEDP is set to the signedness of the field.
2615 *PMASK is set to the mask used. This is either contained in a
2616 BIT_AND_EXPR or derived from the width of the field.
2618 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2620 Return 0 if this is not a component reference or is one that we can't
2621 do anything with. */
2624 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
, HOST_WIDE_INT
*pbitpos
,
2625 enum machine_mode
*pmode
, int *punsignedp
, int *pvolatilep
,
2626 tree
*pmask
, tree
*pand_mask
)
2629 tree mask
, inner
, offset
;
2631 unsigned int precision
;
2633 /* All the optimizations using this function assume integer fields.
2634 There are problems with FP fields since the type_for_size call
2635 below can fail for, e.g., XFmode. */
2636 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
2641 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
2643 and_mask
= TREE_OPERAND (exp
, 1);
2644 exp
= TREE_OPERAND (exp
, 0);
2645 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
2646 if (TREE_CODE (and_mask
) != INTEGER_CST
)
2650 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
2651 punsignedp
, pvolatilep
);
2652 if ((inner
== exp
&& and_mask
== 0)
2653 || *pbitsize
< 0 || offset
!= 0
2654 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
2657 /* Compute the mask to access the bitfield. */
2658 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
2659 precision
= TYPE_PRECISION (unsigned_type
);
2661 mask
= build_int_2 (~0, ~0);
2662 TREE_TYPE (mask
) = unsigned_type
;
2663 force_fit_type (mask
, 0);
2664 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2665 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2667 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2669 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
2670 convert (unsigned_type
, and_mask
), mask
));
2673 *pand_mask
= and_mask
;
2677 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2681 all_ones_mask_p (tree mask
, int size
)
2683 tree type
= TREE_TYPE (mask
);
2684 unsigned int precision
= TYPE_PRECISION (type
);
2687 tmask
= build_int_2 (~0, ~0);
2688 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
2689 force_fit_type (tmask
, 0);
2691 tree_int_cst_equal (mask
,
2692 const_binop (RSHIFT_EXPR
,
2693 const_binop (LSHIFT_EXPR
, tmask
,
2694 size_int (precision
- size
),
2696 size_int (precision
- size
), 0));
2699 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2700 represents the sign bit of EXP's type. If EXP represents a sign
2701 or zero extension, also test VAL against the unextended type.
2702 The return value is the (sub)expression whose sign bit is VAL,
2703 or NULL_TREE otherwise. */
2706 sign_bit_p (tree exp
, tree val
)
2708 unsigned HOST_WIDE_INT lo
;
2713 /* Tree EXP must have an integral type. */
2714 t
= TREE_TYPE (exp
);
2715 if (! INTEGRAL_TYPE_P (t
))
2718 /* Tree VAL must be an integer constant. */
2719 if (TREE_CODE (val
) != INTEGER_CST
2720 || TREE_CONSTANT_OVERFLOW (val
))
2723 width
= TYPE_PRECISION (t
);
2724 if (width
> HOST_BITS_PER_WIDE_INT
)
2726 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
2732 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
2735 if (TREE_INT_CST_HIGH (val
) == hi
&& TREE_INT_CST_LOW (val
) == lo
)
2738 /* Handle extension from a narrower type. */
2739 if (TREE_CODE (exp
) == NOP_EXPR
2740 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
2741 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
2746 /* Subroutine for fold_truthop: determine if an operand is simple enough
2747 to be evaluated unconditionally. */
2750 simple_operand_p (tree exp
)
2752 /* Strip any conversions that don't change the machine mode. */
2753 while ((TREE_CODE (exp
) == NOP_EXPR
2754 || TREE_CODE (exp
) == CONVERT_EXPR
)
2755 && (TYPE_MODE (TREE_TYPE (exp
))
2756 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
2757 exp
= TREE_OPERAND (exp
, 0);
2759 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
2761 && ! TREE_ADDRESSABLE (exp
)
2762 && ! TREE_THIS_VOLATILE (exp
)
2763 && ! DECL_NONLOCAL (exp
)
2764 /* Don't regard global variables as simple. They may be
2765 allocated in ways unknown to the compiler (shared memory,
2766 #pragma weak, etc). */
2767 && ! TREE_PUBLIC (exp
)
2768 && ! DECL_EXTERNAL (exp
)
2769 /* Loading a static variable is unduly expensive, but global
2770 registers aren't expensive. */
2771 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
2774 /* The following functions are subroutines to fold_range_test and allow it to
2775 try to change a logical combination of comparisons into a range test.
2778 X == 2 || X == 3 || X == 4 || X == 5
2782 (unsigned) (X - 2) <= 3
2784 We describe each set of comparisons as being either inside or outside
2785 a range, using a variable named like IN_P, and then describe the
2786 range with a lower and upper bound. If one of the bounds is omitted,
2787 it represents either the highest or lowest value of the type.
2789 In the comments below, we represent a range by two numbers in brackets
2790 preceded by a "+" to designate being inside that range, or a "-" to
2791 designate being outside that range, so the condition can be inverted by
2792 flipping the prefix. An omitted bound is represented by a "-". For
2793 example, "- [-, 10]" means being outside the range starting at the lowest
2794 possible value and ending at 10, in other words, being greater than 10.
2795 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2798 We set up things so that the missing bounds are handled in a consistent
2799 manner so neither a missing bound nor "true" and "false" need to be
2800 handled using a special case. */
2802 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2803 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2804 and UPPER1_P are nonzero if the respective argument is an upper bound
2805 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2806 must be specified for a comparison. ARG1 will be converted to ARG0's
2807 type if both are specified. */
2810 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
, tree arg1
,
2817 /* If neither arg represents infinity, do the normal operation.
2818 Else, if not a comparison, return infinity. Else handle the special
2819 comparison rules. Note that most of the cases below won't occur, but
2820 are handled for consistency. */
2822 if (arg0
!= 0 && arg1
!= 0)
2824 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
2825 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
2827 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
2830 if (TREE_CODE_CLASS (code
) != '<')
2833 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2834 for neither. In real maths, we cannot assume open ended ranges are
2835 the same. But, this is computer arithmetic, where numbers are finite.
2836 We can therefore make the transformation of any unbounded range with
2837 the value Z, Z being greater than any representable number. This permits
2838 us to treat unbounded ranges as equal. */
2839 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
2840 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
2844 result
= sgn0
== sgn1
;
2847 result
= sgn0
!= sgn1
;
2850 result
= sgn0
< sgn1
;
2853 result
= sgn0
<= sgn1
;
2856 result
= sgn0
> sgn1
;
2859 result
= sgn0
>= sgn1
;
2865 return convert (type
, result
? integer_one_node
: integer_zero_node
);
2868 /* Given EXP, a logical expression, set the range it is testing into
2869 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2870 actually being tested. *PLOW and *PHIGH will be made of the same type
2871 as the returned expression. If EXP is not a comparison, we will most
2872 likely not be returning a useful value and range. */
2875 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
)
2877 enum tree_code code
;
2878 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
2879 tree orig_type
= NULL_TREE
;
2881 tree low
, high
, n_low
, n_high
;
2883 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2884 and see if we can refine the range. Some of the cases below may not
2885 happen, but it doesn't seem worth worrying about this. We "continue"
2886 the outer loop when we've changed something; otherwise we "break"
2887 the switch, which will "break" the while. */
2889 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
2893 code
= TREE_CODE (exp
);
2895 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
2897 arg0
= TREE_OPERAND (exp
, 0);
2898 if (TREE_CODE_CLASS (code
) == '<'
2899 || TREE_CODE_CLASS (code
) == '1'
2900 || TREE_CODE_CLASS (code
) == '2')
2901 type
= TREE_TYPE (arg0
);
2902 if (TREE_CODE_CLASS (code
) == '2'
2903 || TREE_CODE_CLASS (code
) == '<'
2904 || (TREE_CODE_CLASS (code
) == 'e'
2905 && TREE_CODE_LENGTH (code
) > 1))
2906 arg1
= TREE_OPERAND (exp
, 1);
2909 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2910 lose a cast by accident. */
2911 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
2916 case TRUTH_NOT_EXPR
:
2917 in_p
= ! in_p
, exp
= arg0
;
2920 case EQ_EXPR
: case NE_EXPR
:
2921 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
2922 /* We can only do something if the range is testing for zero
2923 and if the second operand is an integer constant. Note that
2924 saying something is "in" the range we make is done by
2925 complementing IN_P since it will set in the initial case of
2926 being not equal to zero; "out" is leaving it alone. */
2927 if (low
== 0 || high
== 0
2928 || ! integer_zerop (low
) || ! integer_zerop (high
)
2929 || TREE_CODE (arg1
) != INTEGER_CST
)
2934 case NE_EXPR
: /* - [c, c] */
2937 case EQ_EXPR
: /* + [c, c] */
2938 in_p
= ! in_p
, low
= high
= arg1
;
2940 case GT_EXPR
: /* - [-, c] */
2941 low
= 0, high
= arg1
;
2943 case GE_EXPR
: /* + [c, -] */
2944 in_p
= ! in_p
, low
= arg1
, high
= 0;
2946 case LT_EXPR
: /* - [c, -] */
2947 low
= arg1
, high
= 0;
2949 case LE_EXPR
: /* + [-, c] */
2950 in_p
= ! in_p
, low
= 0, high
= arg1
;
2958 /* If this is an unsigned comparison, we also know that EXP is
2959 greater than or equal to zero. We base the range tests we make
2960 on that fact, so we record it here so we can parse existing
2962 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
2964 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
2965 1, convert (type
, integer_zero_node
),
2969 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
2971 /* If the high bound is missing, but we
2972 have a low bound, reverse the range so
2973 it goes from zero to the low bound minus 1. */
2974 if (high
== 0 && low
)
2977 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
2978 integer_one_node
, 0);
2979 low
= convert (type
, integer_zero_node
);
2985 /* (-x) IN [a,b] -> x in [-b, -a] */
2986 n_low
= range_binop (MINUS_EXPR
, type
,
2987 convert (type
, integer_zero_node
), 0, high
, 1);
2988 n_high
= range_binop (MINUS_EXPR
, type
,
2989 convert (type
, integer_zero_node
), 0, low
, 0);
2990 low
= n_low
, high
= n_high
;
2996 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
2997 convert (type
, integer_one_node
));
3000 case PLUS_EXPR
: case MINUS_EXPR
:
3001 if (TREE_CODE (arg1
) != INTEGER_CST
)
3004 /* If EXP is signed, any overflow in the computation is undefined,
3005 so we don't worry about it so long as our computations on
3006 the bounds don't overflow. For unsigned, overflow is defined
3007 and this is exactly the right thing. */
3008 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3009 type
, low
, 0, arg1
, 0);
3010 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3011 type
, high
, 1, arg1
, 0);
3012 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3013 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3016 /* Check for an unsigned range which has wrapped around the maximum
3017 value thus making n_high < n_low, and normalize it. */
3018 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3020 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3021 integer_one_node
, 0);
3022 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3023 integer_one_node
, 0);
3025 /* If the range is of the form +/- [ x+1, x ], we won't
3026 be able to normalize it. But then, it represents the
3027 whole range or the empty set, so make it
3029 if (tree_int_cst_equal (n_low
, low
)
3030 && tree_int_cst_equal (n_high
, high
))
3036 low
= n_low
, high
= n_high
;
3041 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3042 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3045 if (! INTEGRAL_TYPE_P (type
)
3046 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3047 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3050 n_low
= low
, n_high
= high
;
3053 n_low
= convert (type
, n_low
);
3056 n_high
= convert (type
, n_high
);
3058 /* If we're converting from an unsigned to a signed type,
3059 we will be doing the comparison as unsigned. The tests above
3060 have already verified that LOW and HIGH are both positive.
3062 So we have to make sure that the original unsigned value will
3063 be interpreted as positive. */
3064 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3066 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3067 (TYPE_MODE (type
), 1);
3070 /* A range without an upper bound is, naturally, unbounded.
3071 Since convert would have cropped a very large value, use
3072 the max value for the destination type. */
3074 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3075 : TYPE_MAX_VALUE (type
);
3077 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3078 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3079 convert (type
, high_positive
),
3080 convert (type
, integer_one_node
)));
3082 /* If the low bound is specified, "and" the range with the
3083 range for which the original unsigned value will be
3087 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3089 1, convert (type
, integer_zero_node
),
3093 in_p
= (n_in_p
== in_p
);
3097 /* Otherwise, "or" the range with the range of the input
3098 that will be interpreted as negative. */
3099 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3101 1, convert (type
, integer_zero_node
),
3105 in_p
= (in_p
!= n_in_p
);
3110 low
= n_low
, high
= n_high
;
3120 /* If EXP is a constant, we can evaluate whether this is true or false. */
3121 if (TREE_CODE (exp
) == INTEGER_CST
)
3123 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3125 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3131 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3135 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3136 type, TYPE, return an expression to test if EXP is in (or out of, depending
3137 on IN_P) the range. */
3140 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
3142 tree etype
= TREE_TYPE (exp
);
3146 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3147 return invert_truthvalue (value
);
3149 if (low
== 0 && high
== 0)
3150 return convert (type
, integer_one_node
);
3153 return fold (build (LE_EXPR
, type
, exp
, high
));
3156 return fold (build (GE_EXPR
, type
, exp
, low
));
3158 if (operand_equal_p (low
, high
, 0))
3159 return fold (build (EQ_EXPR
, type
, exp
, low
));
3161 if (integer_zerop (low
))
3163 if (! TREE_UNSIGNED (etype
))
3165 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3166 high
= convert (etype
, high
);
3167 exp
= convert (etype
, exp
);
3169 return build_range_check (type
, exp
, 1, 0, high
);
3172 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3173 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3175 unsigned HOST_WIDE_INT lo
;
3179 prec
= TYPE_PRECISION (etype
);
3180 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3183 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3187 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3188 lo
= (unsigned HOST_WIDE_INT
) -1;
3191 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3193 if (TREE_UNSIGNED (etype
))
3195 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3196 exp
= convert (etype
, exp
);
3198 return fold (build (GT_EXPR
, type
, exp
,
3199 convert (etype
, integer_zero_node
)));
3203 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3204 && ! TREE_OVERFLOW (value
))
3205 return build_range_check (type
,
3206 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3207 1, convert (etype
, integer_zero_node
), value
);
3212 /* Given two ranges, see if we can merge them into one. Return 1 if we
3213 can, 0 if we can't. Set the output range into the specified parameters. */
3216 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
, tree high0
,
3217 int in1_p
, tree low1
, tree high1
)
3225 int lowequal
= ((low0
== 0 && low1
== 0)
3226 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3227 low0
, 0, low1
, 0)));
3228 int highequal
= ((high0
== 0 && high1
== 0)
3229 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3230 high0
, 1, high1
, 1)));
3232 /* Make range 0 be the range that starts first, or ends last if they
3233 start at the same value. Swap them if it isn't. */
3234 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3237 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3238 high1
, 1, high0
, 1))))
3240 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3241 tem
= low0
, low0
= low1
, low1
= tem
;
3242 tem
= high0
, high0
= high1
, high1
= tem
;
3245 /* Now flag two cases, whether the ranges are disjoint or whether the
3246 second range is totally subsumed in the first. Note that the tests
3247 below are simplified by the ones above. */
3248 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3249 high0
, 1, low1
, 0));
3250 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3251 high1
, 1, high0
, 1));
3253 /* We now have four cases, depending on whether we are including or
3254 excluding the two ranges. */
3257 /* If they don't overlap, the result is false. If the second range
3258 is a subset it is the result. Otherwise, the range is from the start
3259 of the second to the end of the first. */
3261 in_p
= 0, low
= high
= 0;
3263 in_p
= 1, low
= low1
, high
= high1
;
3265 in_p
= 1, low
= low1
, high
= high0
;
3268 else if (in0_p
&& ! in1_p
)
3270 /* If they don't overlap, the result is the first range. If they are
3271 equal, the result is false. If the second range is a subset of the
3272 first, and the ranges begin at the same place, we go from just after
3273 the end of the first range to the end of the second. If the second
3274 range is not a subset of the first, or if it is a subset and both
3275 ranges end at the same place, the range starts at the start of the
3276 first range and ends just before the second range.
3277 Otherwise, we can't describe this as a single range. */
3279 in_p
= 1, low
= low0
, high
= high0
;
3280 else if (lowequal
&& highequal
)
3281 in_p
= 0, low
= high
= 0;
3282 else if (subset
&& lowequal
)
3284 in_p
= 1, high
= high0
;
3285 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3286 integer_one_node
, 0);
3288 else if (! subset
|| highequal
)
3290 in_p
= 1, low
= low0
;
3291 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3292 integer_one_node
, 0);
3298 else if (! in0_p
&& in1_p
)
3300 /* If they don't overlap, the result is the second range. If the second
3301 is a subset of the first, the result is false. Otherwise,
3302 the range starts just after the first range and ends at the
3303 end of the second. */
3305 in_p
= 1, low
= low1
, high
= high1
;
3306 else if (subset
|| highequal
)
3307 in_p
= 0, low
= high
= 0;
3310 in_p
= 1, high
= high1
;
3311 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3312 integer_one_node
, 0);
3318 /* The case where we are excluding both ranges. Here the complex case
3319 is if they don't overlap. In that case, the only time we have a
3320 range is if they are adjacent. If the second is a subset of the
3321 first, the result is the first. Otherwise, the range to exclude
3322 starts at the beginning of the first range and ends at the end of the
3326 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3327 range_binop (PLUS_EXPR
, NULL_TREE
,
3329 integer_one_node
, 1),
3331 in_p
= 0, low
= low0
, high
= high1
;
3336 in_p
= 0, low
= low0
, high
= high0
;
3338 in_p
= 0, low
= low0
, high
= high1
;
3341 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3345 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3346 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3349 /* EXP is some logical combination of boolean tests. See if we can
3350 merge it into some range test. Return the new tree if so. */
3353 fold_range_test (tree exp
)
3355 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3356 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3357 int in0_p
, in1_p
, in_p
;
3358 tree low0
, low1
, low
, high0
, high1
, high
;
3359 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3360 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3363 /* If this is an OR operation, invert both sides; we will invert
3364 again at the end. */
3366 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3368 /* If both expressions are the same, if we can merge the ranges, and we
3369 can build the range test, return it or it inverted. If one of the
3370 ranges is always true or always false, consider it to be the same
3371 expression as the other. */
3372 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3373 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3375 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3377 : rhs
!= 0 ? rhs
: integer_zero_node
,
3379 return or_op
? invert_truthvalue (tem
) : tem
;
3381 /* On machines where the branch cost is expensive, if this is a
3382 short-circuited branch and the underlying object on both sides
3383 is the same, make a non-short-circuit operation. */
3384 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3385 && lhs
!= 0 && rhs
!= 0
3386 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3387 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3388 && operand_equal_p (lhs
, rhs
, 0))
3390 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3391 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3392 which cases we can't do this. */
3393 if (simple_operand_p (lhs
))
3394 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3395 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3396 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3397 TREE_OPERAND (exp
, 1));
3399 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3400 && ! CONTAINS_PLACEHOLDER_P (lhs
))
3402 tree common
= save_expr (lhs
);
3404 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3405 or_op
? ! in0_p
: in0_p
,
3407 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3408 or_op
? ! in1_p
: in1_p
,
3410 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3411 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3412 TREE_TYPE (exp
), lhs
, rhs
);
3419 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3420 bit value. Arrange things so the extra bits will be set to zero if and
3421 only if C is signed-extended to its full width. If MASK is nonzero,
3422 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3425 unextend (tree c
, int p
, int unsignedp
, tree mask
)
3427 tree type
= TREE_TYPE (c
);
3428 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3431 if (p
== modesize
|| unsignedp
)
3434 /* We work by getting just the sign bit into the low-order bit, then
3435 into the high-order bit, then sign-extend. We then XOR that value
3437 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3438 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3440 /* We must use a signed type in order to get an arithmetic right shift.
3441 However, we must also avoid introducing accidental overflows, so that
3442 a subsequent call to integer_zerop will work. Hence we must
3443 do the type conversion here. At this point, the constant is either
3444 zero or one, and the conversion to a signed type can never overflow.
3445 We could get an overflow if this conversion is done anywhere else. */
3446 if (TREE_UNSIGNED (type
))
3447 temp
= convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3449 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3450 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3452 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3453 /* If necessary, convert the type back to match the type of C. */
3454 if (TREE_UNSIGNED (type
))
3455 temp
= convert (type
, temp
);
3457 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3460 /* Find ways of folding logical expressions of LHS and RHS:
3461 Try to merge two comparisons to the same innermost item.
3462 Look for range tests like "ch >= '0' && ch <= '9'".
3463 Look for combinations of simple terms on machines with expensive branches
3464 and evaluate the RHS unconditionally.
3466 For example, if we have p->a == 2 && p->b == 4 and we can make an
3467 object large enough to span both A and B, we can do this with a comparison
3468 against the object ANDed with the a mask.
3470 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3471 operations to do this with one comparison.
3473 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3474 function and the one above.
3476 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3477 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3479 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3482 We return the simplified tree or 0 if no optimization is possible. */
3485 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
3487 /* If this is the "or" of two comparisons, we can do something if
3488 the comparisons are NE_EXPR. If this is the "and", we can do something
3489 if the comparisons are EQ_EXPR. I.e.,
3490 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3492 WANTED_CODE is this operation code. For single bit fields, we can
3493 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3494 comparison for one-bit fields. */
3496 enum tree_code wanted_code
;
3497 enum tree_code lcode
, rcode
;
3498 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3499 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3500 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3501 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3502 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3503 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3504 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3505 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3506 enum machine_mode lnmode
, rnmode
;
3507 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3508 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3509 tree l_const
, r_const
;
3510 tree lntype
, rntype
, result
;
3511 int first_bit
, end_bit
;
3514 /* Start by getting the comparison codes. Fail if anything is volatile.
3515 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3516 it were surrounded with a NE_EXPR. */
3518 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3521 lcode
= TREE_CODE (lhs
);
3522 rcode
= TREE_CODE (rhs
);
3524 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3525 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3527 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3528 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3530 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3533 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3534 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3536 ll_arg
= TREE_OPERAND (lhs
, 0);
3537 lr_arg
= TREE_OPERAND (lhs
, 1);
3538 rl_arg
= TREE_OPERAND (rhs
, 0);
3539 rr_arg
= TREE_OPERAND (rhs
, 1);
3541 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3542 if (simple_operand_p (ll_arg
)
3543 && simple_operand_p (lr_arg
)
3544 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3548 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3549 && operand_equal_p (lr_arg
, rr_arg
, 0))
3551 int lcompcode
, rcompcode
;
3553 lcompcode
= comparison_to_compcode (lcode
);
3554 rcompcode
= comparison_to_compcode (rcode
);
3555 compcode
= (code
== TRUTH_AND_EXPR
)
3556 ? lcompcode
& rcompcode
3557 : lcompcode
| rcompcode
;
3559 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3560 && operand_equal_p (lr_arg
, rl_arg
, 0))
3562 int lcompcode
, rcompcode
;
3564 rcode
= swap_tree_comparison (rcode
);
3565 lcompcode
= comparison_to_compcode (lcode
);
3566 rcompcode
= comparison_to_compcode (rcode
);
3567 compcode
= (code
== TRUTH_AND_EXPR
)
3568 ? lcompcode
& rcompcode
3569 : lcompcode
| rcompcode
;
3574 if (compcode
== COMPCODE_TRUE
)
3575 return convert (truth_type
, integer_one_node
);
3576 else if (compcode
== COMPCODE_FALSE
)
3577 return convert (truth_type
, integer_zero_node
);
3578 else if (compcode
!= -1)
3579 return build (compcode_to_comparison (compcode
),
3580 truth_type
, ll_arg
, lr_arg
);
3583 /* If the RHS can be evaluated unconditionally and its operands are
3584 simple, it wins to evaluate the RHS unconditionally on machines
3585 with expensive branches. In this case, this isn't a comparison
3586 that can be merged. Avoid doing this if the RHS is a floating-point
3587 comparison since those can trap. */
3589 if (BRANCH_COST
>= 2
3590 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3591 && simple_operand_p (rl_arg
)
3592 && simple_operand_p (rr_arg
))
3594 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3595 if (code
== TRUTH_OR_EXPR
3596 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
3597 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
3598 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3599 return build (NE_EXPR
, truth_type
,
3600 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3604 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3605 if (code
== TRUTH_AND_EXPR
3606 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
3607 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
3608 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3609 return build (EQ_EXPR
, truth_type
,
3610 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3614 return build (code
, truth_type
, lhs
, rhs
);
3617 /* See if the comparisons can be merged. Then get all the parameters for
3620 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3621 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3625 ll_inner
= decode_field_reference (ll_arg
,
3626 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3627 &ll_unsignedp
, &volatilep
, &ll_mask
,
3629 lr_inner
= decode_field_reference (lr_arg
,
3630 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3631 &lr_unsignedp
, &volatilep
, &lr_mask
,
3633 rl_inner
= decode_field_reference (rl_arg
,
3634 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3635 &rl_unsignedp
, &volatilep
, &rl_mask
,
3637 rr_inner
= decode_field_reference (rr_arg
,
3638 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3639 &rr_unsignedp
, &volatilep
, &rr_mask
,
3642 /* It must be true that the inner operation on the lhs of each
3643 comparison must be the same if we are to be able to do anything.
3644 Then see if we have constants. If not, the same must be true for
3646 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3647 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3650 if (TREE_CODE (lr_arg
) == INTEGER_CST
3651 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3652 l_const
= lr_arg
, r_const
= rr_arg
;
3653 else if (lr_inner
== 0 || rr_inner
== 0
3654 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3657 l_const
= r_const
= 0;
3659 /* If either comparison code is not correct for our logical operation,
3660 fail. However, we can convert a one-bit comparison against zero into
3661 the opposite comparison against that bit being set in the field. */
3663 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3664 if (lcode
!= wanted_code
)
3666 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3668 /* Make the left operand unsigned, since we are only interested
3669 in the value of one bit. Otherwise we are doing the wrong
3678 /* This is analogous to the code for l_const above. */
3679 if (rcode
!= wanted_code
)
3681 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3690 /* After this point all optimizations will generate bit-field
3691 references, which we might not want. */
3692 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
3695 /* See if we can find a mode that contains both fields being compared on
3696 the left. If we can't, fail. Otherwise, update all constants and masks
3697 to be relative to a field of that size. */
3698 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3699 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3700 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3701 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3703 if (lnmode
== VOIDmode
)
3706 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3707 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3708 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
3709 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3711 if (BYTES_BIG_ENDIAN
)
3713 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3714 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3717 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3718 size_int (xll_bitpos
), 0);
3719 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3720 size_int (xrl_bitpos
), 0);
3724 l_const
= convert (lntype
, l_const
);
3725 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3726 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3727 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3728 fold (build1 (BIT_NOT_EXPR
,
3732 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3734 return convert (truth_type
,
3735 wanted_code
== NE_EXPR
3736 ? integer_one_node
: integer_zero_node
);
3741 r_const
= convert (lntype
, r_const
);
3742 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3743 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3744 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3745 fold (build1 (BIT_NOT_EXPR
,
3749 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3751 return convert (truth_type
,
3752 wanted_code
== NE_EXPR
3753 ? integer_one_node
: integer_zero_node
);
3757 /* If the right sides are not constant, do the same for it. Also,
3758 disallow this optimization if a size or signedness mismatch occurs
3759 between the left and right sides. */
3762 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
3763 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
3764 /* Make sure the two fields on the right
3765 correspond to the left without being swapped. */
3766 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
3769 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
3770 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
3771 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3772 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
3774 if (rnmode
== VOIDmode
)
3777 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
3778 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
3779 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
3780 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
3782 if (BYTES_BIG_ENDIAN
)
3784 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
3785 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
3788 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
3789 size_int (xlr_bitpos
), 0);
3790 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
3791 size_int (xrr_bitpos
), 0);
3793 /* Make a mask that corresponds to both fields being compared.
3794 Do this for both items being compared. If the operands are the
3795 same size and the bits being compared are in the same position
3796 then we can do this by masking both and comparing the masked
3798 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3799 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
3800 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
3802 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3803 ll_unsignedp
|| rl_unsignedp
);
3804 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3805 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
3807 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
3808 lr_unsignedp
|| rr_unsignedp
);
3809 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
3810 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
3812 return build (wanted_code
, truth_type
, lhs
, rhs
);
3815 /* There is still another way we can do something: If both pairs of
3816 fields being compared are adjacent, we may be able to make a wider
3817 field containing them both.
3819 Note that we still must mask the lhs/rhs expressions. Furthermore,
3820 the mask must be shifted to account for the shift done by
3821 make_bit_field_ref. */
3822 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
3823 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
3824 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
3825 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
3829 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
3830 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
3831 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
3832 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
3834 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
3835 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
3836 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
3837 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
3839 /* Convert to the smaller type before masking out unwanted bits. */
3841 if (lntype
!= rntype
)
3843 if (lnbitsize
> rnbitsize
)
3845 lhs
= convert (rntype
, lhs
);
3846 ll_mask
= convert (rntype
, ll_mask
);
3849 else if (lnbitsize
< rnbitsize
)
3851 rhs
= convert (lntype
, rhs
);
3852 lr_mask
= convert (lntype
, lr_mask
);
3857 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
3858 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
3860 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
3861 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
3863 return build (wanted_code
, truth_type
, lhs
, rhs
);
3869 /* Handle the case of comparisons with constants. If there is something in
3870 common between the masks, those bits of the constants must be the same.
3871 If not, the condition is always false. Test for this to avoid generating
3872 incorrect code below. */
3873 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
3874 if (! integer_zerop (result
)
3875 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
3876 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
3878 if (wanted_code
== NE_EXPR
)
3880 warning ("`or' of unmatched not-equal tests is always 1");
3881 return convert (truth_type
, integer_one_node
);
3885 warning ("`and' of mutually exclusive equal-tests is always 0");
3886 return convert (truth_type
, integer_zero_node
);
3890 /* Construct the expression we will return. First get the component
3891 reference we will make. Unless the mask is all ones the width of
3892 that field, perform the mask operation. Then compare with the
3894 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3895 ll_unsignedp
|| rl_unsignedp
);
3897 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3898 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3899 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
3901 return build (wanted_code
, truth_type
, result
,
3902 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
3905 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3909 optimize_minmax_comparison (tree t
)
3911 tree type
= TREE_TYPE (t
);
3912 tree arg0
= TREE_OPERAND (t
, 0);
3913 enum tree_code op_code
;
3914 tree comp_const
= TREE_OPERAND (t
, 1);
3916 int consts_equal
, consts_lt
;
3919 STRIP_SIGN_NOPS (arg0
);
3921 op_code
= TREE_CODE (arg0
);
3922 minmax_const
= TREE_OPERAND (arg0
, 1);
3923 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
3924 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
3925 inner
= TREE_OPERAND (arg0
, 0);
3927 /* If something does not permit us to optimize, return the original tree. */
3928 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
3929 || TREE_CODE (comp_const
) != INTEGER_CST
3930 || TREE_CONSTANT_OVERFLOW (comp_const
)
3931 || TREE_CODE (minmax_const
) != INTEGER_CST
3932 || TREE_CONSTANT_OVERFLOW (minmax_const
))
3935 /* Now handle all the various comparison codes. We only handle EQ_EXPR
3936 and GT_EXPR, doing the rest with recursive calls using logical
3938 switch (TREE_CODE (t
))
3940 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
3942 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
3946 fold (build (TRUTH_ORIF_EXPR
, type
,
3947 optimize_minmax_comparison
3948 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
3949 optimize_minmax_comparison
3950 (build (GT_EXPR
, type
, arg0
, comp_const
))));
3953 if (op_code
== MAX_EXPR
&& consts_equal
)
3954 /* MAX (X, 0) == 0 -> X <= 0 */
3955 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
3957 else if (op_code
== MAX_EXPR
&& consts_lt
)
3958 /* MAX (X, 0) == 5 -> X == 5 */
3959 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
3961 else if (op_code
== MAX_EXPR
)
3962 /* MAX (X, 0) == -1 -> false */
3963 return omit_one_operand (type
, integer_zero_node
, inner
);
3965 else if (consts_equal
)
3966 /* MIN (X, 0) == 0 -> X >= 0 */
3967 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
3970 /* MIN (X, 0) == 5 -> false */
3971 return omit_one_operand (type
, integer_zero_node
, inner
);
3974 /* MIN (X, 0) == -1 -> X == -1 */
3975 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
3978 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
3979 /* MAX (X, 0) > 0 -> X > 0
3980 MAX (X, 0) > 5 -> X > 5 */
3981 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
3983 else if (op_code
== MAX_EXPR
)
3984 /* MAX (X, 0) > -1 -> true */
3985 return omit_one_operand (type
, integer_one_node
, inner
);
3987 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
3988 /* MIN (X, 0) > 0 -> false
3989 MIN (X, 0) > 5 -> false */
3990 return omit_one_operand (type
, integer_zero_node
, inner
);
3993 /* MIN (X, 0) > -1 -> X > -1 */
3994 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4001 /* T is an integer expression that is being multiplied, divided, or taken a
4002 modulus (CODE says which and what kind of divide or modulus) by a
4003 constant C. See if we can eliminate that operation by folding it with
4004 other operations already in T. WIDE_TYPE, if non-null, is a type that
4005 should be used for the computation if wider than our type.
4007 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4008 (X * 2) + (Y * 4). We must, however, be assured that either the original
4009 expression would not overflow or that overflow is undefined for the type
4010 in the language in question.
4012 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4013 the machine has a multiply-accumulate insn or that this is part of an
4014 addressing calculation.
4016 If we return a non-null expression, it is an equivalent form of the
4017 original computation, but need not be in the original type. */
4020 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4022 /* To avoid exponential search depth, refuse to allow recursion past
4023 three levels. Beyond that (1) it's highly unlikely that we'll find
4024 something interesting and (2) we've probably processed it before
4025 when we built the inner expression. */
4034 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4041 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4043 tree type
= TREE_TYPE (t
);
4044 enum tree_code tcode
= TREE_CODE (t
);
4045 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4046 > GET_MODE_SIZE (TYPE_MODE (type
)))
4047 ? wide_type
: type
);
4049 int same_p
= tcode
== code
;
4050 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4052 /* Don't deal with constants of zero here; they confuse the code below. */
4053 if (integer_zerop (c
))
4056 if (TREE_CODE_CLASS (tcode
) == '1')
4057 op0
= TREE_OPERAND (t
, 0);
4059 if (TREE_CODE_CLASS (tcode
) == '2')
4060 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4062 /* Note that we need not handle conditional operations here since fold
4063 already handles those cases. So just do arithmetic here. */
4067 /* For a constant, we can always simplify if we are a multiply
4068 or (for divide and modulus) if it is a multiple of our constant. */
4069 if (code
== MULT_EXPR
4070 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4071 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4074 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4075 /* If op0 is an expression ... */
4076 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4077 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4078 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4079 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4080 /* ... and is unsigned, and its type is smaller than ctype,
4081 then we cannot pass through as widening. */
4082 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4083 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4084 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4085 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4086 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4087 /* ... or its type is larger than ctype,
4088 then we cannot pass through this truncation. */
4089 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4090 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
4091 /* ... or signedness changes for division or modulus,
4092 then we cannot pass through this conversion. */
4093 || (code
!= MULT_EXPR
4094 && (TREE_UNSIGNED (ctype
)
4095 != TREE_UNSIGNED (TREE_TYPE (op0
))))))
4098 /* Pass the constant down and see if we can make a simplification. If
4099 we can, replace this expression with the inner simplification for
4100 possible later conversion to our or some other type. */
4101 if ((t2
= convert (TREE_TYPE (op0
), c
)) != 0
4102 && TREE_CODE (t2
) == INTEGER_CST
4103 && ! TREE_CONSTANT_OVERFLOW (t2
)
4104 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
4106 ? ctype
: NULL_TREE
))))
4110 case NEGATE_EXPR
: case ABS_EXPR
:
4111 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4112 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4115 case MIN_EXPR
: case MAX_EXPR
:
4116 /* If widening the type changes the signedness, then we can't perform
4117 this optimization as that changes the result. */
4118 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4121 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4122 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4123 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4125 if (tree_int_cst_sgn (c
) < 0)
4126 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4128 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4129 convert (ctype
, t2
)));
4133 case WITH_RECORD_EXPR
:
4134 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4135 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4136 TREE_OPERAND (t
, 1));
4140 /* If this has not been evaluated and the operand has no side effects,
4141 we can see if we can do something inside it and make a new one.
4142 Note that this test is overly conservative since we can do this
4143 if the only reason it had side effects is that it was another
4144 similar SAVE_EXPR, but that isn't worth bothering with. */
4145 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4146 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4149 t1
= save_expr (t1
);
4150 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4151 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4152 if (is_pending_size (t
))
4153 put_pending_size (t1
);
4158 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4159 /* If the second operand is constant, this is a multiplication
4160 or floor division, by a power of two, so we can treat it that
4161 way unless the multiplier or divisor overflows. */
4162 if (TREE_CODE (op1
) == INTEGER_CST
4163 /* const_binop may not detect overflow correctly,
4164 so check for it explicitly here. */
4165 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4166 && TREE_INT_CST_HIGH (op1
) == 0
4167 && 0 != (t1
= convert (ctype
,
4168 const_binop (LSHIFT_EXPR
, size_one_node
,
4170 && ! TREE_OVERFLOW (t1
))
4171 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4172 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4173 ctype
, convert (ctype
, op0
), t1
),
4174 c
, code
, wide_type
);
4177 case PLUS_EXPR
: case MINUS_EXPR
:
4178 /* See if we can eliminate the operation on both sides. If we can, we
4179 can return a new PLUS or MINUS. If we can't, the only remaining
4180 cases where we can do anything are if the second operand is a
4182 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4183 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4184 if (t1
!= 0 && t2
!= 0
4185 && (code
== MULT_EXPR
4186 /* If not multiplication, we can only do this if both operands
4187 are divisible by c. */
4188 || (multiple_of_p (ctype
, op0
, c
)
4189 && multiple_of_p (ctype
, op1
, c
))))
4190 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4191 convert (ctype
, t2
)));
4193 /* If this was a subtraction, negate OP1 and set it to be an addition.
4194 This simplifies the logic below. */
4195 if (tcode
== MINUS_EXPR
)
4196 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4198 if (TREE_CODE (op1
) != INTEGER_CST
)
4201 /* If either OP1 or C are negative, this optimization is not safe for
4202 some of the division and remainder types while for others we need
4203 to change the code. */
4204 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4206 if (code
== CEIL_DIV_EXPR
)
4207 code
= FLOOR_DIV_EXPR
;
4208 else if (code
== FLOOR_DIV_EXPR
)
4209 code
= CEIL_DIV_EXPR
;
4210 else if (code
!= MULT_EXPR
4211 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4215 /* If it's a multiply or a division/modulus operation of a multiple
4216 of our constant, do the operation and verify it doesn't overflow. */
4217 if (code
== MULT_EXPR
4218 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4220 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4221 if (op1
== 0 || TREE_OVERFLOW (op1
))
4227 /* If we have an unsigned type is not a sizetype, we cannot widen
4228 the operation since it will change the result if the original
4229 computation overflowed. */
4230 if (TREE_UNSIGNED (ctype
)
4231 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4235 /* If we were able to eliminate our operation from the first side,
4236 apply our operation to the second side and reform the PLUS. */
4237 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4238 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4240 /* The last case is if we are a multiply. In that case, we can
4241 apply the distributive law to commute the multiply and addition
4242 if the multiplication of the constants doesn't overflow. */
4243 if (code
== MULT_EXPR
)
4244 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4245 convert (ctype
, op0
),
4246 convert (ctype
, c
))),
4252 /* We have a special case here if we are doing something like
4253 (C * 8) % 4 since we know that's zero. */
4254 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4255 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4256 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4257 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4258 return omit_one_operand (type
, integer_zero_node
, op0
);
4260 /* ... fall through ... */
4262 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4263 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4264 /* If we can extract our operation from the LHS, do so and return a
4265 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4266 do something only if the second operand is a constant. */
4268 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4269 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4270 convert (ctype
, op1
)));
4271 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4272 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4273 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4274 convert (ctype
, t1
)));
4275 else if (TREE_CODE (op1
) != INTEGER_CST
)
4278 /* If these are the same operation types, we can associate them
4279 assuming no overflow. */
4281 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4282 convert (ctype
, c
), 0))
4283 && ! TREE_OVERFLOW (t1
))
4284 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4286 /* If these operations "cancel" each other, we have the main
4287 optimizations of this pass, which occur when either constant is a
4288 multiple of the other, in which case we replace this with either an
4289 operation or CODE or TCODE.
4291 If we have an unsigned type that is not a sizetype, we cannot do
4292 this since it will change the result if the original computation
4294 if ((! TREE_UNSIGNED (ctype
)
4295 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4297 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4298 || (tcode
== MULT_EXPR
4299 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4300 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4302 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4303 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4305 const_binop (TRUNC_DIV_EXPR
,
4307 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4308 return fold (build (code
, ctype
, convert (ctype
, op0
),
4310 const_binop (TRUNC_DIV_EXPR
,
4322 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4323 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4324 that we may sometimes modify the tree. */
4327 strip_compound_expr (tree t
, tree s
)
4329 enum tree_code code
= TREE_CODE (t
);
4331 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4332 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4333 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4334 return TREE_OPERAND (t
, 1);
4336 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4337 don't bother handling any other types. */
4338 else if (code
== COND_EXPR
)
4340 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4341 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4342 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4344 else if (TREE_CODE_CLASS (code
) == '1')
4345 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4346 else if (TREE_CODE_CLASS (code
) == '<'
4347 || TREE_CODE_CLASS (code
) == '2')
4349 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4350 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4356 /* Return a node which has the indicated constant VALUE (either 0 or
4357 1), and is of the indicated TYPE. */
4360 constant_boolean_node (int value
, tree type
)
4362 if (type
== integer_type_node
)
4363 return value
? integer_one_node
: integer_zero_node
;
4364 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4365 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4369 tree t
= build_int_2 (value
, 0);
4371 TREE_TYPE (t
) = type
;
4376 /* Utility function for the following routine, to see how complex a nesting of
4377 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4378 we don't care (to avoid spending too much time on complex expressions.). */
4381 count_cond (tree expr
, int lim
)
4385 if (TREE_CODE (expr
) != COND_EXPR
)
4390 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4391 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4392 return MIN (lim
, 1 + ctrue
+ cfalse
);
4395 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4396 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4397 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4398 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4399 COND is the first argument to CODE; otherwise (as in the example
4400 given here), it is the second argument. TYPE is the type of the
4401 original expression. */
4404 fold_binary_op_with_conditional_arg (enum tree_code code
, tree type
, tree cond
, tree arg
, int cond_first_p
)
4406 tree test
, true_value
, false_value
;
4407 tree lhs
= NULL_TREE
;
4408 tree rhs
= NULL_TREE
;
4409 /* In the end, we'll produce a COND_EXPR. Both arms of the
4410 conditional expression will be binary operations. The left-hand
4411 side of the expression to be executed if the condition is true
4412 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4413 of the expression to be executed if the condition is true will be
4414 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4415 but apply to the expression to be executed if the conditional is
4421 /* These are the codes to use for the left-hand side and right-hand
4422 side of the COND_EXPR. Normally, they are the same as CODE. */
4423 enum tree_code lhs_code
= code
;
4424 enum tree_code rhs_code
= code
;
4425 /* And these are the types of the expressions. */
4426 tree lhs_type
= type
;
4427 tree rhs_type
= type
;
4432 true_rhs
= false_rhs
= &arg
;
4433 true_lhs
= &true_value
;
4434 false_lhs
= &false_value
;
4438 true_lhs
= false_lhs
= &arg
;
4439 true_rhs
= &true_value
;
4440 false_rhs
= &false_value
;
4443 if (TREE_CODE (cond
) == COND_EXPR
)
4445 test
= TREE_OPERAND (cond
, 0);
4446 true_value
= TREE_OPERAND (cond
, 1);
4447 false_value
= TREE_OPERAND (cond
, 2);
4448 /* If this operand throws an expression, then it does not make
4449 sense to try to perform a logical or arithmetic operation
4450 involving it. Instead of building `a + throw 3' for example,
4451 we simply build `a, throw 3'. */
4452 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4456 lhs_code
= COMPOUND_EXPR
;
4457 lhs_type
= void_type_node
;
4462 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4466 rhs_code
= COMPOUND_EXPR
;
4467 rhs_type
= void_type_node
;
4475 tree testtype
= TREE_TYPE (cond
);
4477 true_value
= convert (testtype
, integer_one_node
);
4478 false_value
= convert (testtype
, integer_zero_node
);
4481 /* If ARG is complex we want to make sure we only evaluate it once. Though
4482 this is only required if it is volatile, it might be more efficient even
4483 if it is not. However, if we succeed in folding one part to a constant,
4484 we do not need to make this SAVE_EXPR. Since we do this optimization
4485 primarily to see if we do end up with constant and this SAVE_EXPR
4486 interferes with later optimizations, suppressing it when we can is
4489 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4490 do so. Don't try to see if the result is a constant if an arm is a
4491 COND_EXPR since we get exponential behavior in that case. */
4493 if (saved_expr_p (arg
))
4495 else if (lhs
== 0 && rhs
== 0
4496 && !TREE_CONSTANT (arg
)
4497 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4498 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4499 || TREE_SIDE_EFFECTS (arg
)))
4501 if (TREE_CODE (true_value
) != COND_EXPR
)
4502 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4504 if (TREE_CODE (false_value
) != COND_EXPR
)
4505 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4507 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4508 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4510 arg
= save_expr (arg
);
4517 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4519 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4521 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4524 return build (COMPOUND_EXPR
, type
,
4525 convert (void_type_node
, arg
),
4526 strip_compound_expr (test
, arg
));
4528 return convert (type
, test
);
4532 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4534 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4535 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4536 ADDEND is the same as X.
4538 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4539 and finite. The problematic cases are when X is zero, and its mode
4540 has signed zeros. In the case of rounding towards -infinity,
4541 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4542 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4545 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
4547 if (!real_zerop (addend
))
4550 /* Don't allow the fold with -fsignaling-nans. */
4551 if (HONOR_SNANS (TYPE_MODE (type
)))
4554 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4555 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4558 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4559 if (TREE_CODE (addend
) == REAL_CST
4560 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4563 /* The mode has signed zeros, and we have to honor their sign.
4564 In this situation, there is only one case we can return true for.
4565 X - 0 is the same as X unless rounding towards -infinity is
4567 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4570 /* Subroutine of fold() that checks comparisons of built-in math
4571 functions against real constants.
4573 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4574 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4575 is the type of the result and ARG0 and ARG1 are the operands of the
4576 comparison. ARG1 must be a TREE_REAL_CST.
4578 The function returns the constant folded tree if a simplification
4579 can be made, and NULL_TREE otherwise. */
4582 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
, tree type
, tree arg0
, tree arg1
)
4586 if (fcode
== BUILT_IN_SQRT
4587 || fcode
== BUILT_IN_SQRTF
4588 || fcode
== BUILT_IN_SQRTL
)
4590 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
4591 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
4593 c
= TREE_REAL_CST (arg1
);
4594 if (REAL_VALUE_NEGATIVE (c
))
4596 /* sqrt(x) < y is always false, if y is negative. */
4597 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
4598 return omit_one_operand (type
,
4599 convert (type
, integer_zero_node
),
4602 /* sqrt(x) > y is always true, if y is negative and we
4603 don't care about NaNs, i.e. negative values of x. */
4604 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
4605 return omit_one_operand (type
,
4606 convert (type
, integer_one_node
),
4609 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4610 return fold (build (GE_EXPR
, type
, arg
,
4611 build_real (TREE_TYPE (arg
), dconst0
)));
4613 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
4617 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4618 real_convert (&c2
, mode
, &c2
);
4620 if (REAL_VALUE_ISINF (c2
))
4622 /* sqrt(x) > y is x == +Inf, when y is very large. */
4623 if (HONOR_INFINITIES (mode
))
4624 return fold (build (EQ_EXPR
, type
, arg
,
4625 build_real (TREE_TYPE (arg
), c2
)));
4627 /* sqrt(x) > y is always false, when y is very large
4628 and we don't care about infinities. */
4629 return omit_one_operand (type
,
4630 convert (type
, integer_zero_node
),
4634 /* sqrt(x) > c is the same as x > c*c. */
4635 return fold (build (code
, type
, arg
,
4636 build_real (TREE_TYPE (arg
), c2
)));
4638 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
4642 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4643 real_convert (&c2
, mode
, &c2
);
4645 if (REAL_VALUE_ISINF (c2
))
4647 /* sqrt(x) < y is always true, when y is a very large
4648 value and we don't care about NaNs or Infinities. */
4649 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
4650 return omit_one_operand (type
,
4651 convert (type
, integer_one_node
),
4654 /* sqrt(x) < y is x != +Inf when y is very large and we
4655 don't care about NaNs. */
4656 if (! HONOR_NANS (mode
))
4657 return fold (build (NE_EXPR
, type
, arg
,
4658 build_real (TREE_TYPE (arg
), c2
)));
4660 /* sqrt(x) < y is x >= 0 when y is very large and we
4661 don't care about Infinities. */
4662 if (! HONOR_INFINITIES (mode
))
4663 return fold (build (GE_EXPR
, type
, arg
,
4664 build_real (TREE_TYPE (arg
), dconst0
)));
4666 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4667 if ((*lang_hooks
.decls
.global_bindings_p
) () != 0
4668 || CONTAINS_PLACEHOLDER_P (arg
))
4671 arg
= save_expr (arg
);
4672 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4673 fold (build (GE_EXPR
, type
, arg
,
4674 build_real (TREE_TYPE (arg
),
4676 fold (build (NE_EXPR
, type
, arg
,
4677 build_real (TREE_TYPE (arg
),
4681 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4682 if (! HONOR_NANS (mode
))
4683 return fold (build (code
, type
, arg
,
4684 build_real (TREE_TYPE (arg
), c2
)));
4686 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4687 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4688 && ! CONTAINS_PLACEHOLDER_P (arg
))
4690 arg
= save_expr (arg
);
4691 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4692 fold (build (GE_EXPR
, type
, arg
,
4693 build_real (TREE_TYPE (arg
),
4695 fold (build (code
, type
, arg
,
4696 build_real (TREE_TYPE (arg
),
4705 /* Subroutine of fold() that optimizes comparisons against Infinities,
4706 either +Inf or -Inf.
4708 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4709 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4710 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4712 The function returns the constant folded tree if a simplification
4713 can be made, and NULL_TREE otherwise. */
4716 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
4718 enum machine_mode mode
;
4719 REAL_VALUE_TYPE max
;
4723 mode
= TYPE_MODE (TREE_TYPE (arg0
));
4725 /* For negative infinity swap the sense of the comparison. */
4726 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
4728 code
= swap_tree_comparison (code
);
4733 /* x > +Inf is always false, if with ignore sNANs. */
4734 if (HONOR_SNANS (mode
))
4736 return omit_one_operand (type
,
4737 convert (type
, integer_zero_node
),
4741 /* x <= +Inf is always true, if we don't case about NaNs. */
4742 if (! HONOR_NANS (mode
))
4743 return omit_one_operand (type
,
4744 convert (type
, integer_one_node
),
4747 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4748 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4749 && ! CONTAINS_PLACEHOLDER_P (arg0
))
4751 arg0
= save_expr (arg0
);
4752 return fold (build (EQ_EXPR
, type
, arg0
, arg0
));
4758 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4759 real_maxval (&max
, neg
, mode
);
4760 return fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4761 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4764 /* x < +Inf is always equal to x <= DBL_MAX. */
4765 real_maxval (&max
, neg
, mode
);
4766 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4767 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4770 /* x != +Inf is always equal to !(x > DBL_MAX). */
4771 real_maxval (&max
, neg
, mode
);
4772 if (! HONOR_NANS (mode
))
4773 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4774 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4775 temp
= fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4776 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4777 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
4786 /* Perform constant folding and related simplification of EXPR.
4787 The related simplifications include x*1 => x, x*0 => 0, etc.,
4788 and application of the associative law.
4789 NOP_EXPR conversions may be removed freely (as long as we
4790 are careful not to change the C type of the overall expression)
4791 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4792 but we can constant-fold them if they have constant operands. */
4798 tree t1
= NULL_TREE
;
4800 tree type
= TREE_TYPE (expr
);
4801 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4802 enum tree_code code
= TREE_CODE (t
);
4803 int kind
= TREE_CODE_CLASS (code
);
4805 /* WINS will be nonzero when the switch is done
4806 if all operands are constant. */
4809 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4810 Likewise for a SAVE_EXPR that's already been evaluated. */
4811 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4814 /* Return right away if a constant. */
4818 #ifdef MAX_INTEGER_COMPUTATION_MODE
4819 check_max_integer_computation_mode (expr
);
4822 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4826 /* Special case for conversion ops that can have fixed point args. */
4827 arg0
= TREE_OPERAND (t
, 0);
4829 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4831 STRIP_SIGN_NOPS (arg0
);
4833 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4834 subop
= TREE_REALPART (arg0
);
4838 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4839 && TREE_CODE (subop
) != REAL_CST
4841 /* Note that TREE_CONSTANT isn't enough:
4842 static var addresses are constant but we can't
4843 do arithmetic on them. */
4846 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
4848 int len
= first_rtl_op (code
);
4850 for (i
= 0; i
< len
; i
++)
4852 tree op
= TREE_OPERAND (t
, i
);
4856 continue; /* Valid for CALL_EXPR, at least. */
4858 if (kind
== '<' || code
== RSHIFT_EXPR
)
4860 /* Signedness matters here. Perhaps we can refine this
4862 STRIP_SIGN_NOPS (op
);
4865 /* Strip any conversions that don't change the mode. */
4868 if (TREE_CODE (op
) == COMPLEX_CST
)
4869 subop
= TREE_REALPART (op
);
4873 if (TREE_CODE (subop
) != INTEGER_CST
4874 && TREE_CODE (subop
) != REAL_CST
)
4875 /* Note that TREE_CONSTANT isn't enough:
4876 static var addresses are constant but we can't
4877 do arithmetic on them. */
4887 /* If this is a commutative operation, and ARG0 is a constant, move it
4888 to ARG1 to reduce the number of tests below. */
4889 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
4890 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
4891 || code
== BIT_AND_EXPR
)
4892 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
4894 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
4896 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
4897 TREE_OPERAND (t
, 1) = tem
;
4900 /* Now WINS is set as described above,
4901 ARG0 is the first operand of EXPR,
4902 and ARG1 is the second operand (if it has more than one operand).
4904 First check for cases where an arithmetic operation is applied to a
4905 compound, conditional, or comparison operation. Push the arithmetic
4906 operation inside the compound or conditional to see if any folding
4907 can then be done. Convert comparison to conditional for this purpose.
4908 The also optimizes non-constant cases that used to be done in
4911 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4912 one of the operands is a comparison and the other is a comparison, a
4913 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4914 code below would make the expression more complex. Change it to a
4915 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4916 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4918 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
4919 || code
== EQ_EXPR
|| code
== NE_EXPR
)
4920 && ((truth_value_p (TREE_CODE (arg0
))
4921 && (truth_value_p (TREE_CODE (arg1
))
4922 || (TREE_CODE (arg1
) == BIT_AND_EXPR
4923 && integer_onep (TREE_OPERAND (arg1
, 1)))))
4924 || (truth_value_p (TREE_CODE (arg1
))
4925 && (truth_value_p (TREE_CODE (arg0
))
4926 || (TREE_CODE (arg0
) == BIT_AND_EXPR
4927 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
4929 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
4930 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
4934 if (code
== EQ_EXPR
)
4935 t
= invert_truthvalue (t
);
4940 if (TREE_CODE_CLASS (code
) == '1')
4942 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
4943 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4944 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
4945 else if (TREE_CODE (arg0
) == COND_EXPR
)
4947 tree arg01
= TREE_OPERAND (arg0
, 1);
4948 tree arg02
= TREE_OPERAND (arg0
, 2);
4949 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
4950 arg01
= fold (build1 (code
, type
, arg01
));
4951 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
4952 arg02
= fold (build1 (code
, type
, arg02
));
4953 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4956 /* If this was a conversion, and all we did was to move into
4957 inside the COND_EXPR, bring it back out. But leave it if
4958 it is a conversion from integer to integer and the
4959 result precision is no wider than a word since such a
4960 conversion is cheap and may be optimized away by combine,
4961 while it couldn't if it were outside the COND_EXPR. Then return
4962 so we don't get into an infinite recursion loop taking the
4963 conversion out and then back in. */
4965 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
4966 || code
== NON_LVALUE_EXPR
)
4967 && TREE_CODE (t
) == COND_EXPR
4968 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
4969 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
4970 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
4971 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
4972 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
4973 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
4974 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
4976 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
4977 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
4978 t
= build1 (code
, type
,
4980 TREE_TYPE (TREE_OPERAND
4981 (TREE_OPERAND (t
, 1), 0)),
4982 TREE_OPERAND (t
, 0),
4983 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
4984 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
4987 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
4988 return fold (build (COND_EXPR
, type
, arg0
,
4989 fold (build1 (code
, type
, integer_one_node
)),
4990 fold (build1 (code
, type
, integer_zero_node
))));
4992 else if (TREE_CODE_CLASS (code
) == '<'
4993 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
4994 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4995 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
4996 else if (TREE_CODE_CLASS (code
) == '<'
4997 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
4998 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
4999 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5000 else if (TREE_CODE_CLASS (code
) == '2'
5001 || TREE_CODE_CLASS (code
) == '<')
5003 if (TREE_CODE (arg1
) == COMPOUND_EXPR
5004 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
5005 && ! TREE_SIDE_EFFECTS (arg0
))
5006 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5007 fold (build (code
, type
,
5008 arg0
, TREE_OPERAND (arg1
, 1))));
5009 else if ((TREE_CODE (arg1
) == COND_EXPR
5010 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5011 && TREE_CODE_CLASS (code
) != '<'))
5012 && (TREE_CODE (arg0
) != COND_EXPR
5013 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5014 && (! TREE_SIDE_EFFECTS (arg0
)
5015 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5016 && ! CONTAINS_PLACEHOLDER_P (arg0
))))
5018 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5019 /*cond_first_p=*/0);
5020 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5021 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5022 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5023 else if ((TREE_CODE (arg0
) == COND_EXPR
5024 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5025 && TREE_CODE_CLASS (code
) != '<'))
5026 && (TREE_CODE (arg1
) != COND_EXPR
5027 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5028 && (! TREE_SIDE_EFFECTS (arg1
)
5029 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5030 && ! CONTAINS_PLACEHOLDER_P (arg1
))))
5032 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5033 /*cond_first_p=*/1);
5047 return fold (DECL_INITIAL (t
));
5052 case FIX_TRUNC_EXPR
:
5053 /* Other kinds of FIX are not handled properly by fold_convert. */
5055 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5056 return TREE_OPERAND (t
, 0);
5058 /* Handle cases of two conversions in a row. */
5059 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5060 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5062 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5063 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5064 tree final_type
= TREE_TYPE (t
);
5065 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5066 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5067 int inside_float
= FLOAT_TYPE_P (inside_type
);
5068 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5069 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5070 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5071 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5072 int inter_float
= FLOAT_TYPE_P (inter_type
);
5073 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5074 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5075 int final_int
= INTEGRAL_TYPE_P (final_type
);
5076 int final_ptr
= POINTER_TYPE_P (final_type
);
5077 int final_float
= FLOAT_TYPE_P (final_type
);
5078 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5079 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5081 /* In addition to the cases of two conversions in a row
5082 handled below, if we are converting something to its own
5083 type via an object of identical or wider precision, neither
5084 conversion is needed. */
5085 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5086 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5087 && inter_prec
>= final_prec
)
5088 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5090 /* Likewise, if the intermediate and final types are either both
5091 float or both integer, we don't need the middle conversion if
5092 it is wider than the final type and doesn't change the signedness
5093 (for integers). Avoid this if the final type is a pointer
5094 since then we sometimes need the inner conversion. Likewise if
5095 the outer has a precision not equal to the size of its mode. */
5096 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5097 || (inter_float
&& inside_float
))
5098 && inter_prec
>= inside_prec
5099 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5100 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5101 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5103 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5105 /* If we have a sign-extension of a zero-extended value, we can
5106 replace that by a single zero-extension. */
5107 if (inside_int
&& inter_int
&& final_int
5108 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5109 && inside_unsignedp
&& !inter_unsignedp
)
5110 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5112 /* Two conversions in a row are not needed unless:
5113 - some conversion is floating-point (overstrict for now), or
5114 - the intermediate type is narrower than both initial and
5116 - the intermediate type and innermost type differ in signedness,
5117 and the outermost type is wider than the intermediate, or
5118 - the initial type is a pointer type and the precisions of the
5119 intermediate and final types differ, or
5120 - the final type is a pointer type and the precisions of the
5121 initial and intermediate types differ. */
5122 if (! inside_float
&& ! inter_float
&& ! final_float
5123 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5124 && ! (inside_int
&& inter_int
5125 && inter_unsignedp
!= inside_unsignedp
5126 && inter_prec
< final_prec
)
5127 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5128 == (final_unsignedp
&& final_prec
> inter_prec
))
5129 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5130 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5131 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5132 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5134 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5137 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5138 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5139 /* Detect assigning a bitfield. */
5140 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5141 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5143 /* Don't leave an assignment inside a conversion
5144 unless assigning a bitfield. */
5145 tree prev
= TREE_OPERAND (t
, 0);
5146 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5147 /* First do the assignment, then return converted constant. */
5148 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5153 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5154 constants (if x has signed type, the sign bit cannot be set
5155 in c). This folds extension into the BIT_AND_EXPR. */
5156 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5157 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5158 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5159 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5161 tree
and = TREE_OPERAND (t
, 0);
5162 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5165 if (TREE_UNSIGNED (TREE_TYPE (and))
5166 || (TYPE_PRECISION (TREE_TYPE (t
))
5167 <= TYPE_PRECISION (TREE_TYPE (and))))
5169 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5170 <= HOST_BITS_PER_WIDE_INT
5171 && host_integerp (and1
, 1))
5173 unsigned HOST_WIDE_INT cst
;
5175 cst
= tree_low_cst (and1
, 1);
5176 cst
&= (HOST_WIDE_INT
) -1
5177 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5178 change
= (cst
== 0);
5179 #ifdef LOAD_EXTEND_OP
5181 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5184 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5185 and0
= convert (uns
, and0
);
5186 and1
= convert (uns
, and1
);
5191 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5192 convert (TREE_TYPE (t
), and0
),
5193 convert (TREE_TYPE (t
), and1
)));
5198 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5201 return fold_convert (t
, arg0
);
5203 case VIEW_CONVERT_EXPR
:
5204 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5205 return build1 (VIEW_CONVERT_EXPR
, type
,
5206 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5210 if (TREE_CODE (arg0
) == CONSTRUCTOR
5211 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
5213 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5220 TREE_CONSTANT (t
) = wins
;
5226 if (TREE_CODE (arg0
) == INTEGER_CST
)
5228 unsigned HOST_WIDE_INT low
;
5230 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5231 TREE_INT_CST_HIGH (arg0
),
5233 t
= build_int_2 (low
, high
);
5234 TREE_TYPE (t
) = type
;
5236 = (TREE_OVERFLOW (arg0
)
5237 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5238 TREE_CONSTANT_OVERFLOW (t
)
5239 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5241 else if (TREE_CODE (arg0
) == REAL_CST
)
5242 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5244 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5245 return TREE_OPERAND (arg0
, 0);
5246 /* Convert -((double)float) into (double)(-float). */
5247 else if (TREE_CODE (arg0
) == NOP_EXPR
5248 && TREE_CODE (type
) == REAL_TYPE
)
5250 tree targ0
= strip_float_extensions (arg0
);
5252 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (targ0
), targ0
));
5256 /* Convert - (a - b) to (b - a) for non-floating-point. */
5257 else if (TREE_CODE (arg0
) == MINUS_EXPR
5258 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5259 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5260 TREE_OPERAND (arg0
, 0));
5262 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5263 switch (builtin_mathfn_code (arg0
))
5272 case BUILT_IN_ATANF
:
5273 case BUILT_IN_ATANL
:
5274 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0
, 1))))
5276 tree fndecl
, arg
, arglist
;
5278 fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5279 arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5280 arg
= fold (build1 (NEGATE_EXPR
, type
, arg
));
5281 arglist
= build_tree_list (NULL_TREE
, arg
);
5282 return build_function_call_expr (fndecl
, arglist
);
5294 if (TREE_CODE (arg0
) == INTEGER_CST
)
5296 /* If the value is unsigned, then the absolute value is
5297 the same as the ordinary value. */
5298 if (TREE_UNSIGNED (type
))
5300 /* Similarly, if the value is non-negative. */
5301 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5303 /* If the value is negative, then the absolute value is
5307 unsigned HOST_WIDE_INT low
;
5309 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5310 TREE_INT_CST_HIGH (arg0
),
5312 t
= build_int_2 (low
, high
);
5313 TREE_TYPE (t
) = type
;
5315 = (TREE_OVERFLOW (arg0
)
5316 | force_fit_type (t
, overflow
));
5317 TREE_CONSTANT_OVERFLOW (t
)
5318 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5321 else if (TREE_CODE (arg0
) == REAL_CST
)
5323 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5324 t
= build_real (type
,
5325 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5328 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5329 return fold (build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0)));
5330 /* Convert fabs((double)float) into (double)fabsf(float). */
5331 else if (TREE_CODE (arg0
) == NOP_EXPR
5332 && TREE_CODE (type
) == REAL_TYPE
)
5334 tree targ0
= strip_float_extensions (arg0
);
5336 return convert (type
, fold (build1 (ABS_EXPR
, TREE_TYPE (targ0
),
5339 else if (tree_expr_nonnegative_p (arg0
))
5344 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5345 return convert (type
, arg0
);
5346 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5347 return build (COMPLEX_EXPR
, type
,
5348 TREE_OPERAND (arg0
, 0),
5349 negate_expr (TREE_OPERAND (arg0
, 1)));
5350 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5351 return build_complex (type
, TREE_REALPART (arg0
),
5352 negate_expr (TREE_IMAGPART (arg0
)));
5353 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5354 return fold (build (TREE_CODE (arg0
), type
,
5355 fold (build1 (CONJ_EXPR
, type
,
5356 TREE_OPERAND (arg0
, 0))),
5357 fold (build1 (CONJ_EXPR
,
5358 type
, TREE_OPERAND (arg0
, 1)))));
5359 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5360 return TREE_OPERAND (arg0
, 0);
5366 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5367 ~ TREE_INT_CST_HIGH (arg0
));
5368 TREE_TYPE (t
) = type
;
5369 force_fit_type (t
, 0);
5370 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5371 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5373 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5374 return TREE_OPERAND (arg0
, 0);
5378 /* A + (-B) -> A - B */
5379 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5380 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5381 /* (-A) + B -> B - A */
5382 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5383 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5384 else if (! FLOAT_TYPE_P (type
))
5386 if (integer_zerop (arg1
))
5387 return non_lvalue (convert (type
, arg0
));
5389 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5390 with a constant, and the two constants have no bits in common,
5391 we should treat this as a BIT_IOR_EXPR since this may produce more
5393 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5394 && TREE_CODE (arg1
) == BIT_AND_EXPR
5395 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5396 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5397 && integer_zerop (const_binop (BIT_AND_EXPR
,
5398 TREE_OPERAND (arg0
, 1),
5399 TREE_OPERAND (arg1
, 1), 0)))
5401 code
= BIT_IOR_EXPR
;
5405 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5406 (plus (plus (mult) (mult)) (foo)) so that we can
5407 take advantage of the factoring cases below. */
5408 if ((TREE_CODE (arg0
) == PLUS_EXPR
5409 && TREE_CODE (arg1
) == MULT_EXPR
)
5410 || (TREE_CODE (arg1
) == PLUS_EXPR
5411 && TREE_CODE (arg0
) == MULT_EXPR
))
5413 tree parg0
, parg1
, parg
, marg
;
5415 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5416 parg
= arg0
, marg
= arg1
;
5418 parg
= arg1
, marg
= arg0
;
5419 parg0
= TREE_OPERAND (parg
, 0);
5420 parg1
= TREE_OPERAND (parg
, 1);
5424 if (TREE_CODE (parg0
) == MULT_EXPR
5425 && TREE_CODE (parg1
) != MULT_EXPR
)
5426 return fold (build (PLUS_EXPR
, type
,
5427 fold (build (PLUS_EXPR
, type
,
5428 convert (type
, parg0
),
5429 convert (type
, marg
))),
5430 convert (type
, parg1
)));
5431 if (TREE_CODE (parg0
) != MULT_EXPR
5432 && TREE_CODE (parg1
) == MULT_EXPR
)
5433 return fold (build (PLUS_EXPR
, type
,
5434 fold (build (PLUS_EXPR
, type
,
5435 convert (type
, parg1
),
5436 convert (type
, marg
))),
5437 convert (type
, parg0
)));
5440 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5442 tree arg00
, arg01
, arg10
, arg11
;
5443 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5445 /* (A * C) + (B * C) -> (A+B) * C.
5446 We are most concerned about the case where C is a constant,
5447 but other combinations show up during loop reduction. Since
5448 it is not difficult, try all four possibilities. */
5450 arg00
= TREE_OPERAND (arg0
, 0);
5451 arg01
= TREE_OPERAND (arg0
, 1);
5452 arg10
= TREE_OPERAND (arg1
, 0);
5453 arg11
= TREE_OPERAND (arg1
, 1);
5456 if (operand_equal_p (arg01
, arg11
, 0))
5457 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5458 else if (operand_equal_p (arg00
, arg10
, 0))
5459 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5460 else if (operand_equal_p (arg00
, arg11
, 0))
5461 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5462 else if (operand_equal_p (arg01
, arg10
, 0))
5463 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5465 /* No identical multiplicands; see if we can find a common
5466 power-of-two factor in non-power-of-two multiplies. This
5467 can help in multi-dimensional array access. */
5468 else if (TREE_CODE (arg01
) == INTEGER_CST
5469 && TREE_CODE (arg11
) == INTEGER_CST
5470 && TREE_INT_CST_HIGH (arg01
) == 0
5471 && TREE_INT_CST_HIGH (arg11
) == 0)
5473 HOST_WIDE_INT int01
, int11
, tmp
;
5474 int01
= TREE_INT_CST_LOW (arg01
);
5475 int11
= TREE_INT_CST_LOW (arg11
);
5477 /* Move min of absolute values to int11. */
5478 if ((int01
>= 0 ? int01
: -int01
)
5479 < (int11
>= 0 ? int11
: -int11
))
5481 tmp
= int01
, int01
= int11
, int11
= tmp
;
5482 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5483 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5486 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5488 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5489 build_int_2 (int01
/ int11
, 0)));
5496 return fold (build (MULT_EXPR
, type
,
5497 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5502 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5503 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
5504 return non_lvalue (convert (type
, arg0
));
5506 /* Likewise if the operands are reversed. */
5507 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5508 return non_lvalue (convert (type
, arg1
));
5511 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5512 is a rotate of A by C1 bits. */
5513 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5514 is a rotate of A by B bits. */
5516 enum tree_code code0
, code1
;
5517 code0
= TREE_CODE (arg0
);
5518 code1
= TREE_CODE (arg1
);
5519 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5520 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5521 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5522 TREE_OPERAND (arg1
, 0), 0)
5523 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5525 tree tree01
, tree11
;
5526 enum tree_code code01
, code11
;
5528 tree01
= TREE_OPERAND (arg0
, 1);
5529 tree11
= TREE_OPERAND (arg1
, 1);
5530 STRIP_NOPS (tree01
);
5531 STRIP_NOPS (tree11
);
5532 code01
= TREE_CODE (tree01
);
5533 code11
= TREE_CODE (tree11
);
5534 if (code01
== INTEGER_CST
5535 && code11
== INTEGER_CST
5536 && TREE_INT_CST_HIGH (tree01
) == 0
5537 && TREE_INT_CST_HIGH (tree11
) == 0
5538 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5539 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5540 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5541 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5542 else if (code11
== MINUS_EXPR
)
5544 tree tree110
, tree111
;
5545 tree110
= TREE_OPERAND (tree11
, 0);
5546 tree111
= TREE_OPERAND (tree11
, 1);
5547 STRIP_NOPS (tree110
);
5548 STRIP_NOPS (tree111
);
5549 if (TREE_CODE (tree110
) == INTEGER_CST
5550 && 0 == compare_tree_int (tree110
,
5552 (TREE_TYPE (TREE_OPERAND
5554 && operand_equal_p (tree01
, tree111
, 0))
5555 return build ((code0
== LSHIFT_EXPR
5558 type
, TREE_OPERAND (arg0
, 0), tree01
);
5560 else if (code01
== MINUS_EXPR
)
5562 tree tree010
, tree011
;
5563 tree010
= TREE_OPERAND (tree01
, 0);
5564 tree011
= TREE_OPERAND (tree01
, 1);
5565 STRIP_NOPS (tree010
);
5566 STRIP_NOPS (tree011
);
5567 if (TREE_CODE (tree010
) == INTEGER_CST
5568 && 0 == compare_tree_int (tree010
,
5570 (TREE_TYPE (TREE_OPERAND
5572 && operand_equal_p (tree11
, tree011
, 0))
5573 return build ((code0
!= LSHIFT_EXPR
5576 type
, TREE_OPERAND (arg0
, 0), tree11
);
5582 /* In most languages, can't associate operations on floats through
5583 parentheses. Rather than remember where the parentheses were, we
5584 don't associate floats at all. It shouldn't matter much. However,
5585 associating multiplications is only very slightly inaccurate, so do
5586 that if -funsafe-math-optimizations is specified. */
5589 && (! FLOAT_TYPE_P (type
)
5590 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5592 tree var0
, con0
, lit0
, minus_lit0
;
5593 tree var1
, con1
, lit1
, minus_lit1
;
5595 /* Split both trees into variables, constants, and literals. Then
5596 associate each group together, the constants with literals,
5597 then the result with variables. This increases the chances of
5598 literals being recombined later and of generating relocatable
5599 expressions for the sum of a constant and literal. */
5600 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
5601 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
5602 code
== MINUS_EXPR
);
5604 /* Only do something if we found more than two objects. Otherwise,
5605 nothing has changed and we risk infinite recursion. */
5606 if (2 < ((var0
!= 0) + (var1
!= 0)
5607 + (con0
!= 0) + (con1
!= 0)
5608 + (lit0
!= 0) + (lit1
!= 0)
5609 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
5611 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5612 if (code
== MINUS_EXPR
)
5615 var0
= associate_trees (var0
, var1
, code
, type
);
5616 con0
= associate_trees (con0
, con1
, code
, type
);
5617 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5618 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
5620 /* Preserve the MINUS_EXPR if the negative part of the literal is
5621 greater than the positive part. Otherwise, the multiplicative
5622 folding code (i.e extract_muldiv) may be fooled in case
5623 unsigned constants are subtracted, like in the following
5624 example: ((X*2 + 4) - 8U)/2. */
5625 if (minus_lit0
&& lit0
)
5627 if (tree_int_cst_lt (lit0
, minus_lit0
))
5629 minus_lit0
= associate_trees (minus_lit0
, lit0
,
5635 lit0
= associate_trees (lit0
, minus_lit0
,
5643 return convert (type
, associate_trees (var0
, minus_lit0
,
5647 con0
= associate_trees (con0
, minus_lit0
,
5649 return convert (type
, associate_trees (var0
, con0
,
5654 con0
= associate_trees (con0
, lit0
, code
, type
);
5655 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5661 t1
= const_binop (code
, arg0
, arg1
, 0);
5662 if (t1
!= NULL_TREE
)
5664 /* The return value should always have
5665 the same type as the original expression. */
5666 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5667 t1
= convert (TREE_TYPE (t
), t1
);
5674 /* A - (-B) -> A + B */
5675 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5676 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5677 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5678 if (TREE_CODE (arg0
) == NEGATE_EXPR
5679 && (FLOAT_TYPE_P (type
)
5680 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
5681 && negate_expr_p (arg1
)
5682 && (! TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
5683 && (! TREE_SIDE_EFFECTS (arg1
) || TREE_CONSTANT (arg0
)))
5684 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
5685 TREE_OPERAND (arg0
, 0)));
5687 if (! FLOAT_TYPE_P (type
))
5689 if (! wins
&& integer_zerop (arg0
))
5690 return negate_expr (convert (type
, arg1
));
5691 if (integer_zerop (arg1
))
5692 return non_lvalue (convert (type
, arg0
));
5694 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5695 about the case where C is a constant, just try one of the
5696 four possibilities. */
5698 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5699 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5700 TREE_OPERAND (arg1
, 1), 0))
5701 return fold (build (MULT_EXPR
, type
,
5702 fold (build (MINUS_EXPR
, type
,
5703 TREE_OPERAND (arg0
, 0),
5704 TREE_OPERAND (arg1
, 0))),
5705 TREE_OPERAND (arg0
, 1)));
5707 /* Fold A - (A & B) into ~B & A. */
5708 if (!TREE_SIDE_EFFECTS (arg0
)
5709 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
5711 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
5712 return fold (build (BIT_AND_EXPR
, type
,
5713 fold (build1 (BIT_NOT_EXPR
, type
,
5714 TREE_OPERAND (arg1
, 0))),
5716 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
5717 return fold (build (BIT_AND_EXPR
, type
,
5718 fold (build1 (BIT_NOT_EXPR
, type
,
5719 TREE_OPERAND (arg1
, 1))),
5724 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5725 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
5726 return non_lvalue (convert (type
, arg0
));
5728 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5729 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5730 (-ARG1 + ARG0) reduces to -ARG1. */
5731 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5732 return negate_expr (convert (type
, arg1
));
5734 /* Fold &x - &x. This can happen from &x.foo - &x.
5735 This is unsafe for certain floats even in non-IEEE formats.
5736 In IEEE, it is unsafe because it does wrong for NaNs.
5737 Also note that operand_equal_p is always false if an operand
5740 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5741 && operand_equal_p (arg0
, arg1
, 0))
5742 return convert (type
, integer_zero_node
);
5747 /* (-A) * (-B) -> A * B */
5748 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5749 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5750 TREE_OPERAND (arg1
, 0)));
5752 if (! FLOAT_TYPE_P (type
))
5754 if (integer_zerop (arg1
))
5755 return omit_one_operand (type
, arg1
, arg0
);
5756 if (integer_onep (arg1
))
5757 return non_lvalue (convert (type
, arg0
));
5759 /* (a * (1 << b)) is (a << b) */
5760 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5761 && integer_onep (TREE_OPERAND (arg1
, 0)))
5762 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5763 TREE_OPERAND (arg1
, 1)));
5764 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5765 && integer_onep (TREE_OPERAND (arg0
, 0)))
5766 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5767 TREE_OPERAND (arg0
, 1)));
5769 if (TREE_CODE (arg1
) == INTEGER_CST
5770 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
5771 convert (type
, arg1
),
5773 return convert (type
, tem
);
5778 /* Maybe fold x * 0 to 0. The expressions aren't the same
5779 when x is NaN, since x * 0 is also NaN. Nor are they the
5780 same in modes with signed zeros, since multiplying a
5781 negative value by 0 gives -0, not +0. */
5782 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
5783 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
5784 && real_zerop (arg1
))
5785 return omit_one_operand (type
, arg1
, arg0
);
5786 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5787 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5788 && real_onep (arg1
))
5789 return non_lvalue (convert (type
, arg0
));
5791 /* Transform x * -1.0 into -x. */
5792 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5793 && real_minus_onep (arg1
))
5794 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
5797 if (! wins
&& real_twop (arg1
)
5798 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
5799 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5801 tree arg
= save_expr (arg0
);
5802 return fold (build (PLUS_EXPR
, type
, arg
, arg
));
5805 if (flag_unsafe_math_optimizations
)
5807 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
5808 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
5810 /* Optimizations of sqrt(...)*sqrt(...). */
5811 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
5812 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
5813 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
5815 tree sqrtfn
, arg
, arglist
;
5816 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5817 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5819 /* Optimize sqrt(x)*sqrt(x) as x. */
5820 if (operand_equal_p (arg00
, arg10
, 0)
5821 && ! HONOR_SNANS (TYPE_MODE (type
)))
5824 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5825 sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5826 arg
= fold (build (MULT_EXPR
, type
, arg00
, arg10
));
5827 arglist
= build_tree_list (NULL_TREE
, arg
);
5828 return build_function_call_expr (sqrtfn
, arglist
);
5831 /* Optimize exp(x)*exp(y) as exp(x+y). */
5832 if ((fcode0
== BUILT_IN_EXP
&& fcode1
== BUILT_IN_EXP
)
5833 || (fcode0
== BUILT_IN_EXPF
&& fcode1
== BUILT_IN_EXPF
)
5834 || (fcode0
== BUILT_IN_EXPL
&& fcode1
== BUILT_IN_EXPL
))
5836 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5837 tree arg
= build (PLUS_EXPR
, type
,
5838 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5839 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5840 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
5841 return build_function_call_expr (expfn
, arglist
);
5844 /* Optimizations of pow(...)*pow(...). */
5845 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
5846 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
5847 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
5849 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5850 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
5852 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5853 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
5856 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5857 if (operand_equal_p (arg01
, arg11
, 0))
5859 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5860 tree arg
= build (MULT_EXPR
, type
, arg00
, arg10
);
5861 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
5862 build_tree_list (NULL_TREE
,
5864 return build_function_call_expr (powfn
, arglist
);
5867 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5868 if (operand_equal_p (arg00
, arg10
, 0))
5870 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5871 tree arg
= fold (build (PLUS_EXPR
, type
, arg01
, arg11
));
5872 tree arglist
= tree_cons (NULL_TREE
, arg00
,
5873 build_tree_list (NULL_TREE
,
5875 return build_function_call_expr (powfn
, arglist
);
5879 /* Optimize tan(x)*cos(x) as sin(x). */
5880 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
5881 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
5882 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
5883 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
5884 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
5885 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
5886 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5887 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
5895 sinfn
= implicit_built_in_decls
[BUILT_IN_SIN
];
5899 sinfn
= implicit_built_in_decls
[BUILT_IN_SINF
];
5903 sinfn
= implicit_built_in_decls
[BUILT_IN_SINL
];
5909 if (sinfn
!= NULL_TREE
)
5910 return build_function_call_expr (sinfn
,
5911 TREE_OPERAND (arg0
, 1));
5919 if (integer_all_onesp (arg1
))
5920 return omit_one_operand (type
, arg1
, arg0
);
5921 if (integer_zerop (arg1
))
5922 return non_lvalue (convert (type
, arg0
));
5923 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5924 if (t1
!= NULL_TREE
)
5927 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5929 This results in more efficient code for machines without a NAND
5930 instruction. Combine will canonicalize to the first form
5931 which will allow use of NAND instructions provided by the
5932 backend if they exist. */
5933 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5934 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5936 return fold (build1 (BIT_NOT_EXPR
, type
,
5937 build (BIT_AND_EXPR
, type
,
5938 TREE_OPERAND (arg0
, 0),
5939 TREE_OPERAND (arg1
, 0))));
5942 /* See if this can be simplified into a rotate first. If that
5943 is unsuccessful continue in the association code. */
5947 if (integer_zerop (arg1
))
5948 return non_lvalue (convert (type
, arg0
));
5949 if (integer_all_onesp (arg1
))
5950 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
5952 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5953 with a constant, and the two constants have no bits in common,
5954 we should treat this as a BIT_IOR_EXPR since this may produce more
5956 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5957 && TREE_CODE (arg1
) == BIT_AND_EXPR
5958 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5959 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5960 && integer_zerop (const_binop (BIT_AND_EXPR
,
5961 TREE_OPERAND (arg0
, 1),
5962 TREE_OPERAND (arg1
, 1), 0)))
5964 code
= BIT_IOR_EXPR
;
5968 /* See if this can be simplified into a rotate first. If that
5969 is unsuccessful continue in the association code. */
5974 if (integer_all_onesp (arg1
))
5975 return non_lvalue (convert (type
, arg0
));
5976 if (integer_zerop (arg1
))
5977 return omit_one_operand (type
, arg1
, arg0
);
5978 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5979 if (t1
!= NULL_TREE
)
5981 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
5982 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
5983 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5986 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
5988 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5989 && (~TREE_INT_CST_LOW (arg1
)
5990 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5991 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5994 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5996 This results in more efficient code for machines without a NOR
5997 instruction. Combine will canonicalize to the first form
5998 which will allow use of NOR instructions provided by the
5999 backend if they exist. */
6000 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6001 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6003 return fold (build1 (BIT_NOT_EXPR
, type
,
6004 build (BIT_IOR_EXPR
, type
,
6005 TREE_OPERAND (arg0
, 0),
6006 TREE_OPERAND (arg1
, 0))));
6011 case BIT_ANDTC_EXPR
:
6012 if (integer_all_onesp (arg0
))
6013 return non_lvalue (convert (type
, arg1
));
6014 if (integer_zerop (arg0
))
6015 return omit_one_operand (type
, arg0
, arg1
);
6016 if (TREE_CODE (arg1
) == INTEGER_CST
)
6018 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
6019 code
= BIT_AND_EXPR
;
6025 /* Don't touch a floating-point divide by zero unless the mode
6026 of the constant can represent infinity. */
6027 if (TREE_CODE (arg1
) == REAL_CST
6028 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
6029 && real_zerop (arg1
))
6032 /* (-A) / (-B) -> A / B */
6033 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
6034 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6035 TREE_OPERAND (arg1
, 0)));
6037 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6038 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6039 && real_onep (arg1
))
6040 return non_lvalue (convert (type
, arg0
));
6042 /* If ARG1 is a constant, we can convert this to a multiply by the
6043 reciprocal. This does not have the same rounding properties,
6044 so only do this if -funsafe-math-optimizations. We can actually
6045 always safely do it if ARG1 is a power of two, but it's hard to
6046 tell if it is or not in a portable manner. */
6047 if (TREE_CODE (arg1
) == REAL_CST
)
6049 if (flag_unsafe_math_optimizations
6050 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
6052 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6053 /* Find the reciprocal if optimizing and the result is exact. */
6057 r
= TREE_REAL_CST (arg1
);
6058 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
6060 tem
= build_real (type
, r
);
6061 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6065 /* Convert A/B/C to A/(B*C). */
6066 if (flag_unsafe_math_optimizations
6067 && TREE_CODE (arg0
) == RDIV_EXPR
)
6069 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6070 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
6073 /* Convert A/(B/C) to (A/B)*C. */
6074 if (flag_unsafe_math_optimizations
6075 && TREE_CODE (arg1
) == RDIV_EXPR
)
6077 return fold (build (MULT_EXPR
, type
,
6078 build (RDIV_EXPR
, type
, arg0
,
6079 TREE_OPERAND (arg1
, 0)),
6080 TREE_OPERAND (arg1
, 1)));
6083 if (flag_unsafe_math_optimizations
)
6085 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
6086 /* Optimize x/exp(y) into x*exp(-y). */
6087 if (fcode
== BUILT_IN_EXP
6088 || fcode
== BUILT_IN_EXPF
6089 || fcode
== BUILT_IN_EXPL
)
6091 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6092 tree arg
= build1 (NEGATE_EXPR
, type
,
6093 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6094 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6095 arg1
= build_function_call_expr (expfn
, arglist
);
6096 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6099 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6100 if (fcode
== BUILT_IN_POW
6101 || fcode
== BUILT_IN_POWF
6102 || fcode
== BUILT_IN_POWL
)
6104 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6105 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6106 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
6107 tree neg11
= fold (build1 (NEGATE_EXPR
, type
, arg11
));
6108 tree arglist
= tree_cons(NULL_TREE
, arg10
,
6109 build_tree_list (NULL_TREE
, neg11
));
6110 arg1
= build_function_call_expr (powfn
, arglist
);
6111 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6115 if (flag_unsafe_math_optimizations
)
6117 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6118 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6120 /* Optimize sin(x)/cos(x) as tan(x). */
6121 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
6122 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
6123 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
6124 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6125 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6129 if (fcode0
== BUILT_IN_SIN
)
6130 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6131 else if (fcode0
== BUILT_IN_SINF
)
6132 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6133 else if (fcode0
== BUILT_IN_SINL
)
6134 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6138 if (tanfn
!= NULL_TREE
)
6139 return build_function_call_expr (tanfn
,
6140 TREE_OPERAND (arg0
, 1));
6143 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6144 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
6145 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
6146 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
6147 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6148 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6152 if (fcode0
== BUILT_IN_COS
)
6153 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6154 else if (fcode0
== BUILT_IN_COSF
)
6155 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6156 else if (fcode0
== BUILT_IN_COSL
)
6157 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6161 if (tanfn
!= NULL_TREE
)
6163 tree tmp
= TREE_OPERAND (arg0
, 1);
6164 tmp
= build_function_call_expr (tanfn
, tmp
);
6165 return fold (build (RDIV_EXPR
, type
,
6166 build_real (type
, dconst1
),
6173 case TRUNC_DIV_EXPR
:
6174 case ROUND_DIV_EXPR
:
6175 case FLOOR_DIV_EXPR
:
6177 case EXACT_DIV_EXPR
:
6178 if (integer_onep (arg1
))
6179 return non_lvalue (convert (type
, arg0
));
6180 if (integer_zerop (arg1
))
6183 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6184 operation, EXACT_DIV_EXPR.
6186 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6187 At one time others generated faster code, it's not clear if they do
6188 after the last round to changes to the DIV code in expmed.c. */
6189 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6190 && multiple_of_p (type
, arg0
, arg1
))
6191 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6193 if (TREE_CODE (arg1
) == INTEGER_CST
6194 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6196 return convert (type
, tem
);
6201 case FLOOR_MOD_EXPR
:
6202 case ROUND_MOD_EXPR
:
6203 case TRUNC_MOD_EXPR
:
6204 if (integer_onep (arg1
))
6205 return omit_one_operand (type
, integer_zero_node
, arg0
);
6206 if (integer_zerop (arg1
))
6209 if (TREE_CODE (arg1
) == INTEGER_CST
6210 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6212 return convert (type
, tem
);
6218 if (integer_all_onesp (arg0
))
6219 return omit_one_operand (type
, arg0
, arg1
);
6223 /* Optimize -1 >> x for arithmetic right shifts. */
6224 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
6225 return omit_one_operand (type
, arg0
, arg1
);
6226 /* ... fall through ... */
6230 if (integer_zerop (arg1
))
6231 return non_lvalue (convert (type
, arg0
));
6232 if (integer_zerop (arg0
))
6233 return omit_one_operand (type
, arg0
, arg1
);
6235 /* Since negative shift count is not well-defined,
6236 don't try to compute it in the compiler. */
6237 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6239 /* Rewrite an LROTATE_EXPR by a constant into an
6240 RROTATE_EXPR by a new constant. */
6241 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6243 TREE_SET_CODE (t
, RROTATE_EXPR
);
6244 code
= RROTATE_EXPR
;
6245 TREE_OPERAND (t
, 1) = arg1
6248 convert (TREE_TYPE (arg1
),
6249 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6251 if (tree_int_cst_sgn (arg1
) < 0)
6255 /* If we have a rotate of a bit operation with the rotate count and
6256 the second operand of the bit operation both constant,
6257 permute the two operations. */
6258 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6259 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6260 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6261 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6262 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6263 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6264 return fold (build (TREE_CODE (arg0
), type
,
6265 fold (build (code
, type
,
6266 TREE_OPERAND (arg0
, 0), arg1
)),
6267 fold (build (code
, type
,
6268 TREE_OPERAND (arg0
, 1), arg1
))));
6270 /* Two consecutive rotates adding up to the width of the mode can
6272 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6273 && TREE_CODE (arg0
) == RROTATE_EXPR
6274 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6275 && TREE_INT_CST_HIGH (arg1
) == 0
6276 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6277 && ((TREE_INT_CST_LOW (arg1
)
6278 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6279 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6280 return TREE_OPERAND (arg0
, 0);
6285 if (operand_equal_p (arg0
, arg1
, 0))
6286 return omit_one_operand (type
, arg0
, arg1
);
6287 if (INTEGRAL_TYPE_P (type
)
6288 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6289 return omit_one_operand (type
, arg1
, arg0
);
6293 if (operand_equal_p (arg0
, arg1
, 0))
6294 return omit_one_operand (type
, arg0
, arg1
);
6295 if (INTEGRAL_TYPE_P (type
)
6296 && TYPE_MAX_VALUE (type
)
6297 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6298 return omit_one_operand (type
, arg1
, arg0
);
6301 case TRUTH_NOT_EXPR
:
6302 /* Note that the operand of this must be an int
6303 and its values must be 0 or 1.
6304 ("true" is a fixed value perhaps depending on the language,
6305 but we don't handle values other than 1 correctly yet.) */
6306 tem
= invert_truthvalue (arg0
);
6307 /* Avoid infinite recursion. */
6308 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6310 return convert (type
, tem
);
6312 case TRUTH_ANDIF_EXPR
:
6313 /* Note that the operands of this must be ints
6314 and their values must be 0 or 1.
6315 ("true" is a fixed value perhaps depending on the language.) */
6316 /* If first arg is constant zero, return it. */
6317 if (integer_zerop (arg0
))
6318 return convert (type
, arg0
);
6319 case TRUTH_AND_EXPR
:
6320 /* If either arg is constant true, drop it. */
6321 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6322 return non_lvalue (convert (type
, arg1
));
6323 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6324 /* Preserve sequence points. */
6325 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6326 return non_lvalue (convert (type
, arg0
));
6327 /* If second arg is constant zero, result is zero, but first arg
6328 must be evaluated. */
6329 if (integer_zerop (arg1
))
6330 return omit_one_operand (type
, arg1
, arg0
);
6331 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6332 case will be handled here. */
6333 if (integer_zerop (arg0
))
6334 return omit_one_operand (type
, arg0
, arg1
);
6337 /* We only do these simplifications if we are optimizing. */
6341 /* Check for things like (A || B) && (A || C). We can convert this
6342 to A || (B && C). Note that either operator can be any of the four
6343 truth and/or operations and the transformation will still be
6344 valid. Also note that we only care about order for the
6345 ANDIF and ORIF operators. If B contains side effects, this
6346 might change the truth-value of A. */
6347 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6348 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6349 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6350 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6351 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6352 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6354 tree a00
= TREE_OPERAND (arg0
, 0);
6355 tree a01
= TREE_OPERAND (arg0
, 1);
6356 tree a10
= TREE_OPERAND (arg1
, 0);
6357 tree a11
= TREE_OPERAND (arg1
, 1);
6358 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6359 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6360 && (code
== TRUTH_AND_EXPR
6361 || code
== TRUTH_OR_EXPR
));
6363 if (operand_equal_p (a00
, a10
, 0))
6364 return fold (build (TREE_CODE (arg0
), type
, a00
,
6365 fold (build (code
, type
, a01
, a11
))));
6366 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6367 return fold (build (TREE_CODE (arg0
), type
, a00
,
6368 fold (build (code
, type
, a01
, a10
))));
6369 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6370 return fold (build (TREE_CODE (arg0
), type
, a01
,
6371 fold (build (code
, type
, a00
, a11
))));
6373 /* This case if tricky because we must either have commutative
6374 operators or else A10 must not have side-effects. */
6376 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6377 && operand_equal_p (a01
, a11
, 0))
6378 return fold (build (TREE_CODE (arg0
), type
,
6379 fold (build (code
, type
, a00
, a10
)),
6383 /* See if we can build a range comparison. */
6384 if (0 != (tem
= fold_range_test (t
)))
6387 /* Check for the possibility of merging component references. If our
6388 lhs is another similar operation, try to merge its rhs with our
6389 rhs. Then try to merge our lhs and rhs. */
6390 if (TREE_CODE (arg0
) == code
6391 && 0 != (tem
= fold_truthop (code
, type
,
6392 TREE_OPERAND (arg0
, 1), arg1
)))
6393 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6395 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6400 case TRUTH_ORIF_EXPR
:
6401 /* Note that the operands of this must be ints
6402 and their values must be 0 or true.
6403 ("true" is a fixed value perhaps depending on the language.) */
6404 /* If first arg is constant true, return it. */
6405 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6406 return convert (type
, arg0
);
6408 /* If either arg is constant zero, drop it. */
6409 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6410 return non_lvalue (convert (type
, arg1
));
6411 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6412 /* Preserve sequence points. */
6413 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6414 return non_lvalue (convert (type
, arg0
));
6415 /* If second arg is constant true, result is true, but we must
6416 evaluate first arg. */
6417 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6418 return omit_one_operand (type
, arg1
, arg0
);
6419 /* Likewise for first arg, but note this only occurs here for
6421 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6422 return omit_one_operand (type
, arg0
, arg1
);
6425 case TRUTH_XOR_EXPR
:
6426 /* If either arg is constant zero, drop it. */
6427 if (integer_zerop (arg0
))
6428 return non_lvalue (convert (type
, arg1
));
6429 if (integer_zerop (arg1
))
6430 return non_lvalue (convert (type
, arg0
));
6431 /* If either arg is constant true, this is a logical inversion. */
6432 if (integer_onep (arg0
))
6433 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6434 if (integer_onep (arg1
))
6435 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6444 /* If one arg is a real or integer constant, put it last. */
6445 if ((TREE_CODE (arg0
) == INTEGER_CST
6446 && TREE_CODE (arg1
) != INTEGER_CST
)
6447 || (TREE_CODE (arg0
) == REAL_CST
6448 && TREE_CODE (arg0
) != REAL_CST
))
6450 TREE_OPERAND (t
, 0) = arg1
;
6451 TREE_OPERAND (t
, 1) = arg0
;
6452 arg0
= TREE_OPERAND (t
, 0);
6453 arg1
= TREE_OPERAND (t
, 1);
6454 code
= swap_tree_comparison (code
);
6455 TREE_SET_CODE (t
, code
);
6458 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6460 tree targ0
= strip_float_extensions (arg0
);
6461 tree targ1
= strip_float_extensions (arg1
);
6462 tree newtype
= TREE_TYPE (targ0
);
6464 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
6465 newtype
= TREE_TYPE (targ1
);
6467 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6468 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
6469 return fold (build (code
, type
, convert (newtype
, targ0
),
6470 convert (newtype
, targ1
)));
6472 /* (-a) CMP (-b) -> b CMP a */
6473 if (TREE_CODE (arg0
) == NEGATE_EXPR
6474 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6475 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6476 TREE_OPERAND (arg0
, 0)));
6478 if (TREE_CODE (arg1
) == REAL_CST
)
6480 REAL_VALUE_TYPE cst
;
6481 cst
= TREE_REAL_CST (arg1
);
6483 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6484 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
6486 fold (build (swap_tree_comparison (code
), type
,
6487 TREE_OPERAND (arg0
, 0),
6488 build_real (TREE_TYPE (arg1
),
6489 REAL_VALUE_NEGATE (cst
))));
6491 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6492 /* a CMP (-0) -> a CMP 0 */
6493 if (REAL_VALUE_MINUS_ZERO (cst
))
6494 return fold (build (code
, type
, arg0
,
6495 build_real (TREE_TYPE (arg1
), dconst0
)));
6497 /* x != NaN is always true, other ops are always false. */
6498 if (REAL_VALUE_ISNAN (cst
)
6499 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
6501 t
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
6502 return omit_one_operand (type
, convert (type
, t
), arg0
);
6505 /* Fold comparisons against infinity. */
6506 if (REAL_VALUE_ISINF (cst
))
6508 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
6509 if (tem
!= NULL_TREE
)
6514 /* If this is a comparison of a real constant with a PLUS_EXPR
6515 or a MINUS_EXPR of a real constant, we can convert it into a
6516 comparison with a revised real constant as long as no overflow
6517 occurs when unsafe_math_optimizations are enabled. */
6518 if (flag_unsafe_math_optimizations
6519 && TREE_CODE (arg1
) == REAL_CST
6520 && (TREE_CODE (arg0
) == PLUS_EXPR
6521 || TREE_CODE (arg0
) == MINUS_EXPR
)
6522 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6523 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6524 ? MINUS_EXPR
: PLUS_EXPR
,
6525 arg1
, TREE_OPERAND (arg0
, 1), 0))
6526 && ! TREE_CONSTANT_OVERFLOW (tem
))
6527 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6529 /* Likewise, we can simplify a comparison of a real constant with
6530 a MINUS_EXPR whose first operand is also a real constant, i.e.
6531 (c1 - x) < c2 becomes x > c1-c2. */
6532 if (flag_unsafe_math_optimizations
6533 && TREE_CODE (arg1
) == REAL_CST
6534 && TREE_CODE (arg0
) == MINUS_EXPR
6535 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
6536 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
6538 && ! TREE_CONSTANT_OVERFLOW (tem
))
6539 return fold (build (swap_tree_comparison (code
), type
,
6540 TREE_OPERAND (arg0
, 1), tem
));
6542 /* Fold comparisons against built-in math functions. */
6543 if (TREE_CODE (arg1
) == REAL_CST
6544 && flag_unsafe_math_optimizations
6545 && ! flag_errno_math
)
6547 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
6549 if (fcode
!= END_BUILTINS
)
6551 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
6552 if (tem
!= NULL_TREE
)
6558 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6559 First, see if one arg is constant; find the constant arg
6560 and the other one. */
6562 tree constop
= 0, varop
= NULL_TREE
;
6563 int constopnum
= -1;
6565 if (TREE_CONSTANT (arg1
))
6566 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6567 if (TREE_CONSTANT (arg0
))
6568 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6570 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6572 /* This optimization is invalid for ordered comparisons
6573 if CONST+INCR overflows or if foo+incr might overflow.
6574 This optimization is invalid for floating point due to rounding.
6575 For pointer types we assume overflow doesn't happen. */
6576 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6577 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6578 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6581 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6582 constop
, TREE_OPERAND (varop
, 1)));
6584 /* Do not overwrite the current varop to be a preincrement,
6585 create a new node so that we won't confuse our caller who
6586 might create trees and throw them away, reusing the
6587 arguments that they passed to build. This shows up in
6588 the THEN or ELSE parts of ?: being postincrements. */
6589 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6590 TREE_OPERAND (varop
, 0),
6591 TREE_OPERAND (varop
, 1));
6593 /* If VAROP is a reference to a bitfield, we must mask
6594 the constant by the width of the field. */
6595 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6596 && DECL_BIT_FIELD(TREE_OPERAND
6597 (TREE_OPERAND (varop
, 0), 1)))
6600 = TREE_INT_CST_LOW (DECL_SIZE
6602 (TREE_OPERAND (varop
, 0), 1)));
6603 tree mask
, unsigned_type
;
6604 unsigned int precision
;
6605 tree folded_compare
;
6607 /* First check whether the comparison would come out
6608 always the same. If we don't do that we would
6609 change the meaning with the masking. */
6610 if (constopnum
== 0)
6611 folded_compare
= fold (build (code
, type
, constop
,
6612 TREE_OPERAND (varop
, 0)));
6614 folded_compare
= fold (build (code
, type
,
6615 TREE_OPERAND (varop
, 0),
6617 if (integer_zerop (folded_compare
)
6618 || integer_onep (folded_compare
))
6619 return omit_one_operand (type
, folded_compare
, varop
);
6621 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6622 precision
= TYPE_PRECISION (unsigned_type
);
6623 mask
= build_int_2 (~0, ~0);
6624 TREE_TYPE (mask
) = unsigned_type
;
6625 force_fit_type (mask
, 0);
6626 mask
= const_binop (RSHIFT_EXPR
, mask
,
6627 size_int (precision
- size
), 0);
6628 newconst
= fold (build (BIT_AND_EXPR
,
6629 TREE_TYPE (varop
), newconst
,
6630 convert (TREE_TYPE (varop
),
6634 t
= build (code
, type
,
6635 (constopnum
== 0) ? newconst
: varop
,
6636 (constopnum
== 1) ? newconst
: varop
);
6640 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6642 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6643 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6644 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6647 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6648 constop
, TREE_OPERAND (varop
, 1)));
6650 /* Do not overwrite the current varop to be a predecrement,
6651 create a new node so that we won't confuse our caller who
6652 might create trees and throw them away, reusing the
6653 arguments that they passed to build. This shows up in
6654 the THEN or ELSE parts of ?: being postdecrements. */
6655 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6656 TREE_OPERAND (varop
, 0),
6657 TREE_OPERAND (varop
, 1));
6659 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6660 && DECL_BIT_FIELD(TREE_OPERAND
6661 (TREE_OPERAND (varop
, 0), 1)))
6664 = TREE_INT_CST_LOW (DECL_SIZE
6666 (TREE_OPERAND (varop
, 0), 1)));
6667 tree mask
, unsigned_type
;
6668 unsigned int precision
;
6669 tree folded_compare
;
6671 if (constopnum
== 0)
6672 folded_compare
= fold (build (code
, type
, constop
,
6673 TREE_OPERAND (varop
, 0)));
6675 folded_compare
= fold (build (code
, type
,
6676 TREE_OPERAND (varop
, 0),
6678 if (integer_zerop (folded_compare
)
6679 || integer_onep (folded_compare
))
6680 return omit_one_operand (type
, folded_compare
, varop
);
6682 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6683 precision
= TYPE_PRECISION (unsigned_type
);
6684 mask
= build_int_2 (~0, ~0);
6685 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6686 force_fit_type (mask
, 0);
6687 mask
= const_binop (RSHIFT_EXPR
, mask
,
6688 size_int (precision
- size
), 0);
6689 newconst
= fold (build (BIT_AND_EXPR
,
6690 TREE_TYPE (varop
), newconst
,
6691 convert (TREE_TYPE (varop
),
6695 t
= build (code
, type
,
6696 (constopnum
== 0) ? newconst
: varop
,
6697 (constopnum
== 1) ? newconst
: varop
);
6703 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6704 This transformation affects the cases which are handled in later
6705 optimizations involving comparisons with non-negative constants. */
6706 if (TREE_CODE (arg1
) == INTEGER_CST
6707 && TREE_CODE (arg0
) != INTEGER_CST
6708 && tree_int_cst_sgn (arg1
) > 0)
6714 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6715 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6720 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6721 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6729 /* Comparisons with the highest or lowest possible integer of
6730 the specified size will have known values. */
6732 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6734 if (TREE_CODE (arg1
) == INTEGER_CST
6735 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6736 && width
<= HOST_BITS_PER_WIDE_INT
6737 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6738 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6740 unsigned HOST_WIDE_INT signed_max
;
6741 unsigned HOST_WIDE_INT max
, min
;
6743 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
6745 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6747 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
6753 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
6756 if (TREE_INT_CST_HIGH (arg1
) == 0
6757 && TREE_INT_CST_LOW (arg1
) == max
)
6761 return omit_one_operand (type
,
6762 convert (type
, integer_zero_node
),
6766 TREE_SET_CODE (t
, EQ_EXPR
);
6769 return omit_one_operand (type
,
6770 convert (type
, integer_one_node
),
6774 TREE_SET_CODE (t
, NE_EXPR
);
6777 /* The GE_EXPR and LT_EXPR cases above are not normally
6778 reached because of previous transformations. */
6783 else if (TREE_INT_CST_HIGH (arg1
) == 0
6784 && TREE_INT_CST_LOW (arg1
) == max
- 1)
6789 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6790 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6794 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6795 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6800 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6801 && TREE_INT_CST_LOW (arg1
) == min
)
6805 return omit_one_operand (type
,
6806 convert (type
, integer_zero_node
),
6810 TREE_SET_CODE (t
, EQ_EXPR
);
6814 return omit_one_operand (type
,
6815 convert (type
, integer_one_node
),
6819 TREE_SET_CODE (t
, NE_EXPR
);
6825 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6826 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
6831 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6832 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6836 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6837 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6843 else if (TREE_INT_CST_HIGH (arg1
) == 0
6844 && TREE_INT_CST_LOW (arg1
) == signed_max
6845 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6846 /* signed_type does not work on pointer types. */
6847 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6849 /* The following case also applies to X < signed_max+1
6850 and X >= signed_max+1 because previous transformations. */
6851 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6854 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
6855 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
6857 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
6858 type
, convert (st0
, arg0
),
6859 convert (st1
, integer_zero_node
)));
6865 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6866 a MINUS_EXPR of a constant, we can convert it into a comparison with
6867 a revised constant as long as no overflow occurs. */
6868 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6869 && TREE_CODE (arg1
) == INTEGER_CST
6870 && (TREE_CODE (arg0
) == PLUS_EXPR
6871 || TREE_CODE (arg0
) == MINUS_EXPR
)
6872 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6873 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6874 ? MINUS_EXPR
: PLUS_EXPR
,
6875 arg1
, TREE_OPERAND (arg0
, 1), 0))
6876 && ! TREE_CONSTANT_OVERFLOW (tem
))
6877 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6879 /* Similarly for a NEGATE_EXPR. */
6880 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6881 && TREE_CODE (arg0
) == NEGATE_EXPR
6882 && TREE_CODE (arg1
) == INTEGER_CST
6883 && 0 != (tem
= negate_expr (arg1
))
6884 && TREE_CODE (tem
) == INTEGER_CST
6885 && ! TREE_CONSTANT_OVERFLOW (tem
))
6886 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6888 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6889 for !=. Don't do this for ordered comparisons due to overflow. */
6890 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6891 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6892 return fold (build (code
, type
,
6893 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6895 /* If we are widening one operand of an integer comparison,
6896 see if the other operand is similarly being widened. Perhaps we
6897 can do the comparison in the narrower type. */
6898 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6899 && TREE_CODE (arg0
) == NOP_EXPR
6900 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6901 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6902 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6903 || (TREE_CODE (t1
) == INTEGER_CST
6904 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6905 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6907 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6908 constant, we can simplify it. */
6909 else if (TREE_CODE (arg1
) == INTEGER_CST
6910 && (TREE_CODE (arg0
) == MIN_EXPR
6911 || TREE_CODE (arg0
) == MAX_EXPR
)
6912 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6913 return optimize_minmax_comparison (t
);
6915 /* If we are comparing an ABS_EXPR with a constant, we can
6916 convert all the cases into explicit comparisons, but they may
6917 well not be faster than doing the ABS and one comparison.
6918 But ABS (X) <= C is a range comparison, which becomes a subtraction
6919 and a comparison, and is probably faster. */
6920 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6921 && TREE_CODE (arg0
) == ABS_EXPR
6922 && ! TREE_SIDE_EFFECTS (arg0
)
6923 && (0 != (tem
= negate_expr (arg1
)))
6924 && TREE_CODE (tem
) == INTEGER_CST
6925 && ! TREE_CONSTANT_OVERFLOW (tem
))
6926 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6927 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6928 build (LE_EXPR
, type
,
6929 TREE_OPERAND (arg0
, 0), arg1
)));
6931 /* If this is an EQ or NE comparison with zero and ARG0 is
6932 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6933 two operations, but the latter can be done in one less insn
6934 on machines that have only two-operand insns or on which a
6935 constant cannot be the first operand. */
6936 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6937 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6939 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6940 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6942 fold (build (code
, type
,
6943 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6945 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6946 TREE_OPERAND (arg0
, 1),
6947 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6948 convert (TREE_TYPE (arg0
),
6951 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6952 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6954 fold (build (code
, type
,
6955 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6957 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6958 TREE_OPERAND (arg0
, 0),
6959 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6960 convert (TREE_TYPE (arg0
),
6965 /* If this is an NE or EQ comparison of zero against the result of a
6966 signed MOD operation whose second operand is a power of 2, make
6967 the MOD operation unsigned since it is simpler and equivalent. */
6968 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6969 && integer_zerop (arg1
)
6970 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6971 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6972 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6973 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6974 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6975 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6977 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
6978 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6979 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6980 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6982 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6985 /* If this is an NE comparison of zero with an AND of one, remove the
6986 comparison since the AND will give the correct value. */
6987 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6988 && TREE_CODE (arg0
) == BIT_AND_EXPR
6989 && integer_onep (TREE_OPERAND (arg0
, 1)))
6990 return convert (type
, arg0
);
6992 /* If we have (A & C) == C where C is a power of 2, convert this into
6993 (A & C) != 0. Similarly for NE_EXPR. */
6994 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6995 && TREE_CODE (arg0
) == BIT_AND_EXPR
6996 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6997 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6998 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6999 arg0
, integer_zero_node
));
7001 /* If we have (A & C) != 0 where C is the sign bit of A, convert
7002 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
7003 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7004 && TREE_CODE (arg0
) == BIT_AND_EXPR
7005 && integer_zerop (arg1
))
7007 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0),
7008 TREE_OPERAND (arg0
, 1));
7009 if (arg00
!= NULL_TREE
)
7011 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
7012 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, type
,
7013 convert (stype
, arg00
),
7014 convert (stype
, integer_zero_node
)));
7018 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7019 and similarly for >= into !=. */
7020 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7021 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7022 && TREE_CODE (arg1
) == LSHIFT_EXPR
7023 && integer_onep (TREE_OPERAND (arg1
, 0)))
7024 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7025 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7026 TREE_OPERAND (arg1
, 1)),
7027 convert (TREE_TYPE (arg0
), integer_zero_node
));
7029 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7030 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7031 && (TREE_CODE (arg1
) == NOP_EXPR
7032 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7033 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
7034 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
7036 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7037 convert (TREE_TYPE (arg0
),
7038 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7039 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
7040 convert (TREE_TYPE (arg0
), integer_zero_node
));
7042 /* Simplify comparison of something with itself. (For IEEE
7043 floating-point, we can only do some of these simplifications.) */
7044 if (operand_equal_p (arg0
, arg1
, 0))
7051 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
7052 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7053 return constant_boolean_node (1, type
);
7055 TREE_SET_CODE (t
, code
);
7059 /* For NE, we can only do this simplification if integer
7060 or we don't honor IEEE floating point NaNs. */
7061 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
7062 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7064 /* ... fall through ... */
7067 return constant_boolean_node (0, type
);
7073 /* If we are comparing an expression that just has comparisons
7074 of two integer values, arithmetic expressions of those comparisons,
7075 and constants, we can simplify it. There are only three cases
7076 to check: the two values can either be equal, the first can be
7077 greater, or the second can be greater. Fold the expression for
7078 those three values. Since each value must be 0 or 1, we have
7079 eight possibilities, each of which corresponds to the constant 0
7080 or 1 or one of the six possible comparisons.
7082 This handles common cases like (a > b) == 0 but also handles
7083 expressions like ((x > y) - (y > x)) > 0, which supposedly
7084 occur in macroized code. */
7086 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
7088 tree cval1
= 0, cval2
= 0;
7091 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
7092 /* Don't handle degenerate cases here; they should already
7093 have been handled anyway. */
7094 && cval1
!= 0 && cval2
!= 0
7095 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
7096 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
7097 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
7098 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
7099 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
7100 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
7101 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
7103 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
7104 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
7106 /* We can't just pass T to eval_subst in case cval1 or cval2
7107 was the same as ARG1. */
7110 = fold (build (code
, type
,
7111 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
7114 = fold (build (code
, type
,
7115 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
7118 = fold (build (code
, type
,
7119 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
7122 /* All three of these results should be 0 or 1. Confirm they
7123 are. Then use those values to select the proper code
7126 if ((integer_zerop (high_result
)
7127 || integer_onep (high_result
))
7128 && (integer_zerop (equal_result
)
7129 || integer_onep (equal_result
))
7130 && (integer_zerop (low_result
)
7131 || integer_onep (low_result
)))
7133 /* Make a 3-bit mask with the high-order bit being the
7134 value for `>', the next for '=', and the low for '<'. */
7135 switch ((integer_onep (high_result
) * 4)
7136 + (integer_onep (equal_result
) * 2)
7137 + integer_onep (low_result
))
7141 return omit_one_operand (type
, integer_zero_node
, arg0
);
7162 return omit_one_operand (type
, integer_one_node
, arg0
);
7165 t
= build (code
, type
, cval1
, cval2
);
7167 return save_expr (t
);
7174 /* If this is a comparison of a field, we may be able to simplify it. */
7175 if (((TREE_CODE (arg0
) == COMPONENT_REF
7176 && (*lang_hooks
.can_use_bit_fields_p
) ())
7177 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
7178 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7179 /* Handle the constant case even without -O
7180 to make sure the warnings are given. */
7181 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
7183 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
7187 /* If this is a comparison of complex values and either or both sides
7188 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7189 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7190 This may prevent needless evaluations. */
7191 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7192 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
7193 && (TREE_CODE (arg0
) == COMPLEX_EXPR
7194 || TREE_CODE (arg1
) == COMPLEX_EXPR
7195 || TREE_CODE (arg0
) == COMPLEX_CST
7196 || TREE_CODE (arg1
) == COMPLEX_CST
))
7198 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
7199 tree real0
, imag0
, real1
, imag1
;
7201 arg0
= save_expr (arg0
);
7202 arg1
= save_expr (arg1
);
7203 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
7204 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
7205 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
7206 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
7208 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
7211 fold (build (code
, type
, real0
, real1
)),
7212 fold (build (code
, type
, imag0
, imag1
))));
7215 /* Optimize comparisons of strlen vs zero to a compare of the
7216 first character of the string vs zero. To wit,
7217 strlen(ptr) == 0 => *ptr == 0
7218 strlen(ptr) != 0 => *ptr != 0
7219 Other cases should reduce to one of these two (or a constant)
7220 due to the return value of strlen being unsigned. */
7221 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7222 && integer_zerop (arg1
)
7223 && TREE_CODE (arg0
) == CALL_EXPR
7224 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
7226 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7229 if (TREE_CODE (fndecl
) == FUNCTION_DECL
7230 && DECL_BUILT_IN (fndecl
)
7231 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
7232 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
7233 && (arglist
= TREE_OPERAND (arg0
, 1))
7234 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
7235 && ! TREE_CHAIN (arglist
))
7236 return fold (build (code
, type
,
7237 build1 (INDIRECT_REF
, char_type_node
,
7238 TREE_VALUE(arglist
)),
7239 integer_zero_node
));
7242 /* From here on, the only cases we handle are when the result is
7243 known to be a constant.
7245 To compute GT, swap the arguments and do LT.
7246 To compute GE, do LT and invert the result.
7247 To compute LE, swap the arguments, do LT and invert the result.
7248 To compute NE, do EQ and invert the result.
7250 Therefore, the code below must handle only EQ and LT. */
7252 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7254 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
7255 code
= swap_tree_comparison (code
);
7258 /* Note that it is safe to invert for real values here because we
7259 will check below in the one case that it matters. */
7263 if (code
== NE_EXPR
|| code
== GE_EXPR
)
7266 code
= invert_tree_comparison (code
);
7269 /* Compute a result for LT or EQ if args permit;
7270 otherwise return T. */
7271 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
7273 if (code
== EQ_EXPR
)
7274 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
7276 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
7277 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
7278 : INT_CST_LT (arg0
, arg1
)),
7282 #if 0 /* This is no longer useful, but breaks some real code. */
7283 /* Assume a nonexplicit constant cannot equal an explicit one,
7284 since such code would be undefined anyway.
7285 Exception: on sysvr4, using #pragma weak,
7286 a label can come out as 0. */
7287 else if (TREE_CODE (arg1
) == INTEGER_CST
7288 && !integer_zerop (arg1
)
7289 && TREE_CONSTANT (arg0
)
7290 && TREE_CODE (arg0
) == ADDR_EXPR
7292 t1
= build_int_2 (0, 0);
7294 /* Two real constants can be compared explicitly. */
7295 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
7297 /* If either operand is a NaN, the result is false with two
7298 exceptions: First, an NE_EXPR is true on NaNs, but that case
7299 is already handled correctly since we will be inverting the
7300 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7301 or a GE_EXPR into a LT_EXPR, we must return true so that it
7302 will be inverted into false. */
7304 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
7305 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
7306 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
7308 else if (code
== EQ_EXPR
)
7309 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
7310 TREE_REAL_CST (arg1
)),
7313 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
7314 TREE_REAL_CST (arg1
)),
7318 if (t1
== NULL_TREE
)
7322 TREE_INT_CST_LOW (t1
) ^= 1;
7324 TREE_TYPE (t1
) = type
;
7325 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7326 return (*lang_hooks
.truthvalue_conversion
) (t1
);
7330 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7331 so all simple results must be passed through pedantic_non_lvalue. */
7332 if (TREE_CODE (arg0
) == INTEGER_CST
)
7333 return pedantic_non_lvalue
7334 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7335 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7336 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7338 /* If the second operand is zero, invert the comparison and swap
7339 the second and third operands. Likewise if the second operand
7340 is constant and the third is not or if the third operand is
7341 equivalent to the first operand of the comparison. */
7343 if (integer_zerop (arg1
)
7344 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7345 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7346 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7347 TREE_OPERAND (t
, 2),
7348 TREE_OPERAND (arg0
, 1))))
7350 /* See if this can be inverted. If it can't, possibly because
7351 it was a floating-point inequality comparison, don't do
7353 tem
= invert_truthvalue (arg0
);
7355 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7357 t
= build (code
, type
, tem
,
7358 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7360 /* arg1 should be the first argument of the new T. */
7361 arg1
= TREE_OPERAND (t
, 1);
7366 /* If we have A op B ? A : C, we may be able to convert this to a
7367 simpler expression, depending on the operation and the values
7368 of B and C. Signed zeros prevent all of these transformations,
7369 for reasons given above each one. */
7371 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7372 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7373 arg1
, TREE_OPERAND (arg0
, 1))
7374 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
7376 tree arg2
= TREE_OPERAND (t
, 2);
7377 enum tree_code comp_code
= TREE_CODE (arg0
);
7381 /* If we have A op 0 ? A : -A, consider applying the following
7384 A == 0? A : -A same as -A
7385 A != 0? A : -A same as A
7386 A >= 0? A : -A same as abs (A)
7387 A > 0? A : -A same as abs (A)
7388 A <= 0? A : -A same as -abs (A)
7389 A < 0? A : -A same as -abs (A)
7391 None of these transformations work for modes with signed
7392 zeros. If A is +/-0, the first two transformations will
7393 change the sign of the result (from +0 to -0, or vice
7394 versa). The last four will fix the sign of the result,
7395 even though the original expressions could be positive or
7396 negative, depending on the sign of A.
7398 Note that all these transformations are correct if A is
7399 NaN, since the two alternatives (A and -A) are also NaNs. */
7400 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7401 ? real_zerop (TREE_OPERAND (arg0
, 1))
7402 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7403 && TREE_CODE (arg2
) == NEGATE_EXPR
7404 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7412 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7415 return pedantic_non_lvalue (convert (type
, arg1
));
7418 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7419 arg1
= convert ((*lang_hooks
.types
.signed_type
)
7420 (TREE_TYPE (arg1
)), arg1
);
7421 return pedantic_non_lvalue
7422 (convert (type
, fold (build1 (ABS_EXPR
,
7423 TREE_TYPE (arg1
), arg1
))));
7426 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7427 arg1
= convert ((lang_hooks
.types
.signed_type
)
7428 (TREE_TYPE (arg1
)), arg1
);
7429 return pedantic_non_lvalue
7430 (negate_expr (convert (type
,
7431 fold (build1 (ABS_EXPR
,
7438 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7439 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7440 both transformations are correct when A is NaN: A != 0
7441 is then true, and A == 0 is false. */
7443 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7445 if (comp_code
== NE_EXPR
)
7446 return pedantic_non_lvalue (convert (type
, arg1
));
7447 else if (comp_code
== EQ_EXPR
)
7448 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7451 /* Try some transformations of A op B ? A : B.
7453 A == B? A : B same as B
7454 A != B? A : B same as A
7455 A >= B? A : B same as max (A, B)
7456 A > B? A : B same as max (B, A)
7457 A <= B? A : B same as min (A, B)
7458 A < B? A : B same as min (B, A)
7460 As above, these transformations don't work in the presence
7461 of signed zeros. For example, if A and B are zeros of
7462 opposite sign, the first two transformations will change
7463 the sign of the result. In the last four, the original
7464 expressions give different results for (A=+0, B=-0) and
7465 (A=-0, B=+0), but the transformed expressions do not.
7467 The first two transformations are correct if either A or B
7468 is a NaN. In the first transformation, the condition will
7469 be false, and B will indeed be chosen. In the case of the
7470 second transformation, the condition A != B will be true,
7471 and A will be chosen.
7473 The conversions to max() and min() are not correct if B is
7474 a number and A is not. The conditions in the original
7475 expressions will be false, so all four give B. The min()
7476 and max() versions would give a NaN instead. */
7477 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7478 arg2
, TREE_OPERAND (arg0
, 0)))
7480 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7481 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7482 tree comp_type
= TREE_TYPE (comp_op0
);
7484 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7485 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7495 return pedantic_non_lvalue (convert (type
, arg2
));
7497 return pedantic_non_lvalue (convert (type
, arg1
));
7500 /* In C++ a ?: expression can be an lvalue, so put the
7501 operand which will be used if they are equal first
7502 so that we can convert this back to the
7503 corresponding COND_EXPR. */
7504 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7505 return pedantic_non_lvalue
7506 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7507 (comp_code
== LE_EXPR
7508 ? comp_op0
: comp_op1
),
7509 (comp_code
== LE_EXPR
7510 ? comp_op1
: comp_op0
)))));
7514 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7515 return pedantic_non_lvalue
7516 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7517 (comp_code
== GE_EXPR
7518 ? comp_op0
: comp_op1
),
7519 (comp_code
== GE_EXPR
7520 ? comp_op1
: comp_op0
)))));
7527 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7528 we might still be able to simplify this. For example,
7529 if C1 is one less or one more than C2, this might have started
7530 out as a MIN or MAX and been transformed by this function.
7531 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7533 if (INTEGRAL_TYPE_P (type
)
7534 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7535 && TREE_CODE (arg2
) == INTEGER_CST
)
7539 /* We can replace A with C1 in this case. */
7540 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7541 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7542 TREE_OPERAND (t
, 2));
7546 /* If C1 is C2 + 1, this is min(A, C2). */
7547 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7548 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7549 const_binop (PLUS_EXPR
, arg2
,
7550 integer_one_node
, 0), 1))
7551 return pedantic_non_lvalue
7552 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7556 /* If C1 is C2 - 1, this is min(A, C2). */
7557 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7558 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7559 const_binop (MINUS_EXPR
, arg2
,
7560 integer_one_node
, 0), 1))
7561 return pedantic_non_lvalue
7562 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7566 /* If C1 is C2 - 1, this is max(A, C2). */
7567 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7568 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7569 const_binop (MINUS_EXPR
, arg2
,
7570 integer_one_node
, 0), 1))
7571 return pedantic_non_lvalue
7572 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7576 /* If C1 is C2 + 1, this is max(A, C2). */
7577 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7578 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7579 const_binop (PLUS_EXPR
, arg2
,
7580 integer_one_node
, 0), 1))
7581 return pedantic_non_lvalue
7582 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7591 /* If the second operand is simpler than the third, swap them
7592 since that produces better jump optimization results. */
7593 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7594 || TREE_CODE (arg1
) == SAVE_EXPR
)
7595 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7596 || DECL_P (TREE_OPERAND (t
, 2))
7597 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7599 /* See if this can be inverted. If it can't, possibly because
7600 it was a floating-point inequality comparison, don't do
7602 tem
= invert_truthvalue (arg0
);
7604 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7606 t
= build (code
, type
, tem
,
7607 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7609 /* arg1 should be the first argument of the new T. */
7610 arg1
= TREE_OPERAND (t
, 1);
7615 /* Convert A ? 1 : 0 to simply A. */
7616 if (integer_onep (TREE_OPERAND (t
, 1))
7617 && integer_zerop (TREE_OPERAND (t
, 2))
7618 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7619 call to fold will try to move the conversion inside
7620 a COND, which will recurse. In that case, the COND_EXPR
7621 is probably the best choice, so leave it alone. */
7622 && type
== TREE_TYPE (arg0
))
7623 return pedantic_non_lvalue (arg0
);
7625 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7626 over COND_EXPR in cases such as floating point comparisons. */
7627 if (integer_zerop (TREE_OPERAND (t
, 1))
7628 && integer_onep (TREE_OPERAND (t
, 2))
7629 && truth_value_p (TREE_CODE (arg0
)))
7630 return pedantic_non_lvalue (convert (type
,
7631 invert_truthvalue (arg0
)));
7633 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7634 operation is simply A & 2. */
7636 if (integer_zerop (TREE_OPERAND (t
, 2))
7637 && TREE_CODE (arg0
) == NE_EXPR
7638 && integer_zerop (TREE_OPERAND (arg0
, 1))
7639 && integer_pow2p (arg1
)
7640 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7641 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7643 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7645 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7646 if (integer_zerop (TREE_OPERAND (t
, 2))
7647 && truth_value_p (TREE_CODE (arg0
))
7648 && truth_value_p (TREE_CODE (arg1
)))
7649 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
7652 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7653 if (integer_onep (TREE_OPERAND (t
, 2))
7654 && truth_value_p (TREE_CODE (arg0
))
7655 && truth_value_p (TREE_CODE (arg1
)))
7657 /* Only perform transformation if ARG0 is easily inverted. */
7658 tem
= invert_truthvalue (arg0
);
7659 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7660 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
7667 /* When pedantic, a compound expression can be neither an lvalue
7668 nor an integer constant expression. */
7669 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7671 /* Don't let (0, 0) be null pointer constant. */
7672 if (integer_zerop (arg1
))
7673 return build1 (NOP_EXPR
, type
, arg1
);
7674 return convert (type
, arg1
);
7678 return build_complex (type
, arg0
, arg1
);
7682 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7684 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7685 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7686 TREE_OPERAND (arg0
, 1));
7687 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7688 return TREE_REALPART (arg0
);
7689 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7690 return fold (build (TREE_CODE (arg0
), type
,
7691 fold (build1 (REALPART_EXPR
, type
,
7692 TREE_OPERAND (arg0
, 0))),
7693 fold (build1 (REALPART_EXPR
,
7694 type
, TREE_OPERAND (arg0
, 1)))));
7698 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7699 return convert (type
, integer_zero_node
);
7700 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7701 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7702 TREE_OPERAND (arg0
, 0));
7703 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7704 return TREE_IMAGPART (arg0
);
7705 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7706 return fold (build (TREE_CODE (arg0
), type
,
7707 fold (build1 (IMAGPART_EXPR
, type
,
7708 TREE_OPERAND (arg0
, 0))),
7709 fold (build1 (IMAGPART_EXPR
, type
,
7710 TREE_OPERAND (arg0
, 1)))));
7713 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7715 case CLEANUP_POINT_EXPR
:
7716 if (! has_cleanups (arg0
))
7717 return TREE_OPERAND (t
, 0);
7720 enum tree_code code0
= TREE_CODE (arg0
);
7721 int kind0
= TREE_CODE_CLASS (code0
);
7722 tree arg00
= TREE_OPERAND (arg0
, 0);
7725 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7726 return fold (build1 (code0
, type
,
7727 fold (build1 (CLEANUP_POINT_EXPR
,
7728 TREE_TYPE (arg00
), arg00
))));
7730 if (kind0
== '<' || kind0
== '2'
7731 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7732 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7733 || code0
== TRUTH_XOR_EXPR
)
7735 arg01
= TREE_OPERAND (arg0
, 1);
7737 if (TREE_CONSTANT (arg00
)
7738 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7739 && ! has_cleanups (arg00
)))
7740 return fold (build (code0
, type
, arg00
,
7741 fold (build1 (CLEANUP_POINT_EXPR
,
7742 TREE_TYPE (arg01
), arg01
))));
7744 if (TREE_CONSTANT (arg01
))
7745 return fold (build (code0
, type
,
7746 fold (build1 (CLEANUP_POINT_EXPR
,
7747 TREE_TYPE (arg00
), arg00
)),
7755 /* Check for a built-in function. */
7756 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7757 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7759 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7761 tree tmp
= fold_builtin (expr
);
7769 } /* switch (code) */
7772 /* Determine if first argument is a multiple of second argument. Return 0 if
7773 it is not, or we cannot easily determined it to be.
7775 An example of the sort of thing we care about (at this point; this routine
7776 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7777 fold cases do now) is discovering that
7779 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7785 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7787 This code also handles discovering that
7789 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7791 is a multiple of 8 so we don't have to worry about dealing with a
7794 Note that we *look* inside a SAVE_EXPR only to determine how it was
7795 calculated; it is not safe for fold to do much of anything else with the
7796 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7797 at run time. For example, the latter example above *cannot* be implemented
7798 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7799 evaluation time of the original SAVE_EXPR is not necessarily the same at
7800 the time the new expression is evaluated. The only optimization of this
7801 sort that would be valid is changing
7803 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7807 SAVE_EXPR (I) * SAVE_EXPR (J)
7809 (where the same SAVE_EXPR (J) is used in the original and the
7810 transformed version). */
7813 multiple_of_p (tree type
, tree top
, tree bottom
)
7815 if (operand_equal_p (top
, bottom
, 0))
7818 if (TREE_CODE (type
) != INTEGER_TYPE
)
7821 switch (TREE_CODE (top
))
7824 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7825 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7829 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7830 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7833 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7837 op1
= TREE_OPERAND (top
, 1);
7838 /* const_binop may not detect overflow correctly,
7839 so check for it explicitly here. */
7840 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7841 > TREE_INT_CST_LOW (op1
)
7842 && TREE_INT_CST_HIGH (op1
) == 0
7843 && 0 != (t1
= convert (type
,
7844 const_binop (LSHIFT_EXPR
, size_one_node
,
7846 && ! TREE_OVERFLOW (t1
))
7847 return multiple_of_p (type
, t1
, bottom
);
7852 /* Can't handle conversions from non-integral or wider integral type. */
7853 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7854 || (TYPE_PRECISION (type
)
7855 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7858 /* .. fall through ... */
7861 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7864 if (TREE_CODE (bottom
) != INTEGER_CST
7865 || (TREE_UNSIGNED (type
)
7866 && (tree_int_cst_sgn (top
) < 0
7867 || tree_int_cst_sgn (bottom
) < 0)))
7869 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7877 /* Return true if `t' is known to be non-negative. */
7880 tree_expr_nonnegative_p (tree t
)
7882 switch (TREE_CODE (t
))
7892 /* These are undefined at zero. This is true even if
7893 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7894 computing here is a user-visible property. */
7898 return tree_int_cst_sgn (t
) >= 0;
7901 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
7904 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
7905 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7906 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7908 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
7909 both unsigned and at least 2 bits shorter than the result. */
7910 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
7911 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
7912 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
7914 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
7915 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
7916 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
7917 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
7919 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
7920 TYPE_PRECISION (inner2
)) + 1;
7921 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
7927 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
7929 /* x * x for floating point x is always non-negative. */
7930 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
7932 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7933 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7936 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
7937 both unsigned and their total bits is shorter than the result. */
7938 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
7939 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
7940 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
7942 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
7943 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
7944 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
7945 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
7946 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
7947 < TYPE_PRECISION (TREE_TYPE (t
));
7951 case TRUNC_DIV_EXPR
:
7953 case FLOOR_DIV_EXPR
:
7954 case ROUND_DIV_EXPR
:
7955 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7956 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7958 case TRUNC_MOD_EXPR
:
7960 case FLOOR_MOD_EXPR
:
7961 case ROUND_MOD_EXPR
:
7962 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7965 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7966 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7970 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
7971 tree outer_type
= TREE_TYPE (t
);
7973 if (TREE_CODE (outer_type
) == REAL_TYPE
)
7975 if (TREE_CODE (inner_type
) == REAL_TYPE
)
7976 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7977 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
7979 if (TREE_UNSIGNED (inner_type
))
7981 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7984 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
7986 if (TREE_CODE (inner_type
) == REAL_TYPE
)
7987 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
7988 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
7989 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
7990 && TREE_UNSIGNED (inner_type
);
7996 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
7997 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
7999 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8001 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8002 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8004 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8005 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8007 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8009 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8011 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8012 case NON_LVALUE_EXPR
:
8013 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8015 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
8018 if (TREE_CODE (TREE_OPERAND (t
, 0)) == ADDR_EXPR
)
8020 tree fndecl
= TREE_OPERAND (TREE_OPERAND (t
, 0), 0);
8021 tree arglist
= TREE_OPERAND (t
, 1);
8022 if (TREE_CODE (fndecl
) == FUNCTION_DECL
8023 && DECL_BUILT_IN (fndecl
)
8024 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
)
8025 switch (DECL_FUNCTION_CODE (fndecl
))
8028 case BUILT_IN_CABSL
:
8029 case BUILT_IN_CABSF
:
8034 case BUILT_IN_FABSF
:
8035 case BUILT_IN_FABSL
:
8037 case BUILT_IN_SQRTF
:
8038 case BUILT_IN_SQRTL
:
8042 case BUILT_IN_ATANF
:
8043 case BUILT_IN_ATANL
:
8045 case BUILT_IN_CEILF
:
8046 case BUILT_IN_CEILL
:
8047 case BUILT_IN_FLOOR
:
8048 case BUILT_IN_FLOORF
:
8049 case BUILT_IN_FLOORL
:
8050 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8055 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8062 /* ... fall through ... */
8065 if (truth_value_p (TREE_CODE (t
)))
8066 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8070 /* We don't know sign of `t', so be conservative and return false. */
8074 /* Return true if `r' is known to be non-negative.
8075 Only handles constants at the moment. */
8078 rtl_expr_nonnegative_p (rtx r
)
8080 switch (GET_CODE (r
))
8083 return INTVAL (r
) >= 0;
8086 if (GET_MODE (r
) == VOIDmode
)
8087 return CONST_DOUBLE_HIGH (r
) >= 0;
8095 units
= CONST_VECTOR_NUNITS (r
);
8097 for (i
= 0; i
< units
; ++i
)
8099 elt
= CONST_VECTOR_ELT (r
, i
);
8100 if (!rtl_expr_nonnegative_p (elt
))
8109 /* These are always nonnegative. */
8117 #include "gt-fold-const.h"