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"
61 static void encode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
, HOST_WIDE_INT
);
62 static void decode (HOST_WIDE_INT
*, unsigned HOST_WIDE_INT
*, HOST_WIDE_INT
*);
63 static bool negate_expr_p (tree
);
64 static tree
negate_expr (tree
);
65 static tree
split_tree (tree
, enum tree_code
, tree
*, tree
*, tree
*, int);
66 static tree
associate_trees (tree
, tree
, enum tree_code
, tree
);
67 static tree
int_const_binop (enum tree_code
, tree
, tree
, int);
68 static tree
const_binop (enum tree_code
, tree
, tree
, int);
69 static hashval_t
size_htab_hash (const void *);
70 static int size_htab_eq (const void *, const void *);
71 static tree
fold_convert (tree
, tree
);
72 static enum tree_code
invert_tree_comparison (enum tree_code
);
73 static enum tree_code
swap_tree_comparison (enum tree_code
);
74 static int comparison_to_compcode (enum tree_code
);
75 static enum tree_code
compcode_to_comparison (int);
76 static int truth_value_p (enum tree_code
);
77 static int operand_equal_for_comparison_p (tree
, tree
, tree
);
78 static int twoval_comparison_p (tree
, tree
*, tree
*, int *);
79 static tree
eval_subst (tree
, tree
, tree
, tree
, tree
);
80 static tree
pedantic_omit_one_operand (tree
, tree
, tree
);
81 static tree
distribute_bit_expr (enum tree_code
, tree
, tree
, tree
);
82 static tree
make_bit_field_ref (tree
, tree
, int, int, int);
83 static tree
optimize_bit_field_compare (enum tree_code
, tree
, tree
, tree
);
84 static tree
decode_field_reference (tree
, HOST_WIDE_INT
*, HOST_WIDE_INT
*,
85 enum machine_mode
*, int *, int *,
87 static int all_ones_mask_p (tree
, int);
88 static tree
sign_bit_p (tree
, tree
);
89 static int simple_operand_p (tree
);
90 static tree
range_binop (enum tree_code
, tree
, tree
, int, tree
, int);
91 static tree
make_range (tree
, int *, tree
*, tree
*);
92 static tree
build_range_check (tree
, tree
, int, tree
, tree
);
93 static int merge_ranges (int *, tree
*, tree
*, int, tree
, tree
, int, tree
,
95 static tree
fold_range_test (tree
);
96 static tree
unextend (tree
, int, int, tree
);
97 static tree
fold_truthop (enum tree_code
, tree
, tree
, tree
);
98 static tree
optimize_minmax_comparison (tree
);
99 static tree
extract_muldiv (tree
, tree
, enum tree_code
, tree
);
100 static tree
extract_muldiv_1 (tree
, tree
, enum tree_code
, tree
);
101 static tree
strip_compound_expr (tree
, tree
);
102 static int multiple_of_p (tree
, tree
, tree
);
103 static tree
constant_boolean_node (int, tree
);
104 static int count_cond (tree
, int);
105 static tree
fold_binary_op_with_conditional_arg (enum tree_code
, tree
, tree
,
107 static bool fold_real_zero_addition_p (tree
, tree
, int);
108 static tree
fold_mathfn_compare (enum built_in_function
, enum tree_code
,
110 static tree
fold_inf_compare (enum tree_code
, tree
, tree
, tree
);
112 /* The following constants represent a bit based encoding of GCC's
113 comparison operators. This encoding simplifies transformations
114 on relational comparison operators, such as AND and OR. */
115 #define COMPCODE_FALSE 0
116 #define COMPCODE_LT 1
117 #define COMPCODE_EQ 2
118 #define COMPCODE_LE 3
119 #define COMPCODE_GT 4
120 #define COMPCODE_NE 5
121 #define COMPCODE_GE 6
122 #define COMPCODE_TRUE 7
124 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
125 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
126 and SUM1. Then this yields nonzero if overflow occurred during the
129 Overflow occurs if A and B have the same sign, but A and SUM differ in
130 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
132 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
134 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
135 We do that by representing the two-word integer in 4 words, with only
136 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
137 number. The value of the word is LOWPART + HIGHPART * BASE. */
140 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
141 #define HIGHPART(x) \
142 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
143 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
145 /* Unpack a two-word integer into 4 words.
146 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
147 WORDS points to the array of HOST_WIDE_INTs. */
150 encode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT low
, HOST_WIDE_INT hi
)
152 words
[0] = LOWPART (low
);
153 words
[1] = HIGHPART (low
);
154 words
[2] = LOWPART (hi
);
155 words
[3] = HIGHPART (hi
);
158 /* Pack an array of 4 words into a two-word integer.
159 WORDS points to the array of words.
160 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
163 decode (HOST_WIDE_INT
*words
, unsigned HOST_WIDE_INT
*low
,
166 *low
= words
[0] + words
[1] * BASE
;
167 *hi
= words
[2] + words
[3] * BASE
;
170 /* Make the integer constant T valid for its type by setting to 0 or 1 all
171 the bits in the constant that don't belong in the type.
173 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
174 nonzero, a signed overflow has already occurred in calculating T, so
178 force_fit_type (tree t
, int overflow
)
180 unsigned HOST_WIDE_INT low
;
184 if (TREE_CODE (t
) == REAL_CST
)
186 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
187 Consider doing it via real_convert now. */
191 else if (TREE_CODE (t
) != INTEGER_CST
)
194 low
= TREE_INT_CST_LOW (t
);
195 high
= TREE_INT_CST_HIGH (t
);
197 if (POINTER_TYPE_P (TREE_TYPE (t
))
198 || TREE_CODE (TREE_TYPE (t
)) == OFFSET_TYPE
)
201 prec
= TYPE_PRECISION (TREE_TYPE (t
));
203 /* First clear all bits that are beyond the type's precision. */
205 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
207 else if (prec
> HOST_BITS_PER_WIDE_INT
)
208 TREE_INT_CST_HIGH (t
)
209 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
212 TREE_INT_CST_HIGH (t
) = 0;
213 if (prec
< HOST_BITS_PER_WIDE_INT
)
214 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
217 /* Unsigned types do not suffer sign extension or overflow unless they
219 if (TREE_UNSIGNED (TREE_TYPE (t
))
220 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
221 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
224 /* If the value's sign bit is set, extend the sign. */
225 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
226 && (prec
> HOST_BITS_PER_WIDE_INT
227 ? 0 != (TREE_INT_CST_HIGH (t
)
229 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
230 : 0 != (TREE_INT_CST_LOW (t
)
231 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
233 /* Value is negative:
234 set to 1 all the bits that are outside this type's precision. */
235 if (prec
> HOST_BITS_PER_WIDE_INT
)
236 TREE_INT_CST_HIGH (t
)
237 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
240 TREE_INT_CST_HIGH (t
) = -1;
241 if (prec
< HOST_BITS_PER_WIDE_INT
)
242 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
246 /* Return nonzero if signed overflow occurred. */
248 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
252 /* Add two doubleword integers with doubleword result.
253 Each argument is given as two `HOST_WIDE_INT' pieces.
254 One argument is L1 and H1; the other, L2 and H2.
255 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
258 add_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
259 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
260 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
262 unsigned HOST_WIDE_INT l
;
266 h
= h1
+ h2
+ (l
< l1
);
270 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
273 /* Negate a doubleword integer with doubleword result.
274 Return nonzero if the operation overflows, assuming it's signed.
275 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
276 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
279 neg_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
280 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
286 return (*hv
& h1
) < 0;
296 /* Multiply two doubleword integers with doubleword result.
297 Return nonzero if the operation overflows, assuming it's signed.
298 Each argument is given as two `HOST_WIDE_INT' pieces.
299 One argument is L1 and H1; the other, L2 and H2.
300 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
303 mul_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
304 unsigned HOST_WIDE_INT l2
, HOST_WIDE_INT h2
,
305 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
307 HOST_WIDE_INT arg1
[4];
308 HOST_WIDE_INT arg2
[4];
309 HOST_WIDE_INT prod
[4 * 2];
310 unsigned HOST_WIDE_INT carry
;
312 unsigned HOST_WIDE_INT toplow
, neglow
;
313 HOST_WIDE_INT tophigh
, neghigh
;
315 encode (arg1
, l1
, h1
);
316 encode (arg2
, l2
, h2
);
318 memset (prod
, 0, sizeof prod
);
320 for (i
= 0; i
< 4; i
++)
323 for (j
= 0; j
< 4; j
++)
326 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
327 carry
+= arg1
[i
] * arg2
[j
];
328 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
330 prod
[k
] = LOWPART (carry
);
331 carry
= HIGHPART (carry
);
336 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
338 /* Check for overflow by calculating the top half of the answer in full;
339 it should agree with the low half's sign bit. */
340 decode (prod
+ 4, &toplow
, &tophigh
);
343 neg_double (l2
, h2
, &neglow
, &neghigh
);
344 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
348 neg_double (l1
, h1
, &neglow
, &neghigh
);
349 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
351 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
354 /* Shift the doubleword integer in L1, H1 left by COUNT places
355 keeping only PREC bits of result.
356 Shift right if COUNT is negative.
357 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
358 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
361 lshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
362 HOST_WIDE_INT count
, unsigned int prec
,
363 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
, int arith
)
365 unsigned HOST_WIDE_INT signmask
;
369 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
373 #ifdef SHIFT_COUNT_TRUNCATED
374 if (SHIFT_COUNT_TRUNCATED
)
378 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
380 /* Shifting by the host word size is undefined according to the
381 ANSI standard, so we must handle this as a special case. */
385 else if (count
>= HOST_BITS_PER_WIDE_INT
)
387 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
392 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
393 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
397 /* Sign extend all bits that are beyond the precision. */
399 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
400 ? ((unsigned HOST_WIDE_INT
) *hv
401 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
402 : (*lv
>> (prec
- 1))) & 1);
404 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
406 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
408 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
409 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
414 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
415 *lv
|= signmask
<< prec
;
419 /* Shift the doubleword integer in L1, H1 right by COUNT places
420 keeping only PREC bits of result. COUNT must be positive.
421 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
422 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
425 rshift_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
426 HOST_WIDE_INT count
, unsigned int prec
,
427 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
,
430 unsigned HOST_WIDE_INT signmask
;
433 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
436 #ifdef SHIFT_COUNT_TRUNCATED
437 if (SHIFT_COUNT_TRUNCATED
)
441 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
443 /* Shifting by the host word size is undefined according to the
444 ANSI standard, so we must handle this as a special case. */
448 else if (count
>= HOST_BITS_PER_WIDE_INT
)
451 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
455 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
457 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
460 /* Zero / sign extend all bits that are beyond the precision. */
462 if (count
>= (HOST_WIDE_INT
)prec
)
467 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
469 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
471 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
472 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
477 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
478 *lv
|= signmask
<< (prec
- count
);
482 /* Rotate the doubleword integer in L1, H1 left by COUNT places
483 keeping only PREC bits of result.
484 Rotate right if COUNT is negative.
485 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
488 lrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
489 HOST_WIDE_INT count
, unsigned int prec
,
490 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
492 unsigned HOST_WIDE_INT s1l
, s2l
;
493 HOST_WIDE_INT s1h
, s2h
;
499 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
500 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
505 /* Rotate the doubleword integer in L1, H1 left by COUNT places
506 keeping only PREC bits of result. COUNT must be positive.
507 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
510 rrotate_double (unsigned HOST_WIDE_INT l1
, HOST_WIDE_INT h1
,
511 HOST_WIDE_INT count
, unsigned int prec
,
512 unsigned HOST_WIDE_INT
*lv
, HOST_WIDE_INT
*hv
)
514 unsigned HOST_WIDE_INT s1l
, s2l
;
515 HOST_WIDE_INT s1h
, s2h
;
521 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
522 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
527 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
528 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
529 CODE is a tree code for a kind of division, one of
530 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
532 It controls how the quotient is rounded to an integer.
533 Return nonzero if the operation overflows.
534 UNS nonzero says do unsigned division. */
537 div_and_round_double (enum tree_code code
, int uns
,
538 unsigned HOST_WIDE_INT lnum_orig
, /* num == numerator == dividend */
539 HOST_WIDE_INT hnum_orig
,
540 unsigned HOST_WIDE_INT lden_orig
, /* den == denominator == divisor */
541 HOST_WIDE_INT hden_orig
,
542 unsigned HOST_WIDE_INT
*lquo
,
543 HOST_WIDE_INT
*hquo
, unsigned HOST_WIDE_INT
*lrem
,
547 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
548 HOST_WIDE_INT den
[4], quo
[4];
550 unsigned HOST_WIDE_INT work
;
551 unsigned HOST_WIDE_INT carry
= 0;
552 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
553 HOST_WIDE_INT hnum
= hnum_orig
;
554 unsigned HOST_WIDE_INT lden
= lden_orig
;
555 HOST_WIDE_INT hden
= hden_orig
;
558 if (hden
== 0 && lden
== 0)
559 overflow
= 1, lden
= 1;
561 /* calculate quotient sign and convert operands to unsigned. */
567 /* (minimum integer) / (-1) is the only overflow case. */
568 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
569 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
575 neg_double (lden
, hden
, &lden
, &hden
);
579 if (hnum
== 0 && hden
== 0)
580 { /* single precision */
582 /* This unsigned division rounds toward zero. */
588 { /* trivial case: dividend < divisor */
589 /* hden != 0 already checked. */
596 memset (quo
, 0, sizeof quo
);
598 memset (num
, 0, sizeof num
); /* to zero 9th element */
599 memset (den
, 0, sizeof den
);
601 encode (num
, lnum
, hnum
);
602 encode (den
, lden
, hden
);
604 /* Special code for when the divisor < BASE. */
605 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
607 /* hnum != 0 already checked. */
608 for (i
= 4 - 1; i
>= 0; i
--)
610 work
= num
[i
] + carry
* BASE
;
611 quo
[i
] = work
/ lden
;
617 /* Full double precision division,
618 with thanks to Don Knuth's "Seminumerical Algorithms". */
619 int num_hi_sig
, den_hi_sig
;
620 unsigned HOST_WIDE_INT quo_est
, scale
;
622 /* Find the highest nonzero divisor digit. */
623 for (i
= 4 - 1;; i
--)
630 /* Insure that the first digit of the divisor is at least BASE/2.
631 This is required by the quotient digit estimation algorithm. */
633 scale
= BASE
/ (den
[den_hi_sig
] + 1);
635 { /* scale divisor and dividend */
637 for (i
= 0; i
<= 4 - 1; i
++)
639 work
= (num
[i
] * scale
) + carry
;
640 num
[i
] = LOWPART (work
);
641 carry
= HIGHPART (work
);
646 for (i
= 0; i
<= 4 - 1; i
++)
648 work
= (den
[i
] * scale
) + carry
;
649 den
[i
] = LOWPART (work
);
650 carry
= HIGHPART (work
);
651 if (den
[i
] != 0) den_hi_sig
= i
;
658 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
660 /* Guess the next quotient digit, quo_est, by dividing the first
661 two remaining dividend digits by the high order quotient digit.
662 quo_est is never low and is at most 2 high. */
663 unsigned HOST_WIDE_INT tmp
;
665 num_hi_sig
= i
+ den_hi_sig
+ 1;
666 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
667 if (num
[num_hi_sig
] != den
[den_hi_sig
])
668 quo_est
= work
/ den
[den_hi_sig
];
672 /* Refine quo_est so it's usually correct, and at most one high. */
673 tmp
= work
- quo_est
* den
[den_hi_sig
];
675 && (den
[den_hi_sig
- 1] * quo_est
676 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
679 /* Try QUO_EST as the quotient digit, by multiplying the
680 divisor by QUO_EST and subtracting from the remaining dividend.
681 Keep in mind that QUO_EST is the I - 1st digit. */
684 for (j
= 0; j
<= den_hi_sig
; j
++)
686 work
= quo_est
* den
[j
] + carry
;
687 carry
= HIGHPART (work
);
688 work
= num
[i
+ j
] - LOWPART (work
);
689 num
[i
+ j
] = LOWPART (work
);
690 carry
+= HIGHPART (work
) != 0;
693 /* If quo_est was high by one, then num[i] went negative and
694 we need to correct things. */
695 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
698 carry
= 0; /* add divisor back in */
699 for (j
= 0; j
<= den_hi_sig
; j
++)
701 work
= num
[i
+ j
] + den
[j
] + carry
;
702 carry
= HIGHPART (work
);
703 num
[i
+ j
] = LOWPART (work
);
706 num
[num_hi_sig
] += carry
;
709 /* Store the quotient digit. */
714 decode (quo
, lquo
, hquo
);
717 /* If result is negative, make it so. */
719 neg_double (*lquo
, *hquo
, lquo
, hquo
);
721 /* compute trial remainder: rem = num - (quo * den) */
722 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
723 neg_double (*lrem
, *hrem
, lrem
, hrem
);
724 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
729 case TRUNC_MOD_EXPR
: /* round toward zero */
730 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
734 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
735 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
738 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
746 case CEIL_MOD_EXPR
: /* round toward positive infinity */
747 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
749 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
757 case ROUND_MOD_EXPR
: /* round to closest integer */
759 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
760 HOST_WIDE_INT habs_rem
= *hrem
;
761 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
762 HOST_WIDE_INT habs_den
= hden
, htwice
;
764 /* Get absolute values. */
766 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
768 neg_double (lden
, hden
, &labs_den
, &habs_den
);
770 /* If (2 * abs (lrem) >= abs (lden)) */
771 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
772 labs_rem
, habs_rem
, <wice
, &htwice
);
774 if (((unsigned HOST_WIDE_INT
) habs_den
775 < (unsigned HOST_WIDE_INT
) htwice
)
776 || (((unsigned HOST_WIDE_INT
) habs_den
777 == (unsigned HOST_WIDE_INT
) htwice
)
778 && (labs_den
< ltwice
)))
782 add_double (*lquo
, *hquo
,
783 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
786 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
798 /* compute true remainder: rem = num - (quo * den) */
799 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
800 neg_double (*lrem
, *hrem
, lrem
, hrem
);
801 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
805 /* Determine whether an expression T can be cheaply negated using
806 the function negate_expr. */
809 negate_expr_p (tree t
)
811 unsigned HOST_WIDE_INT val
;
818 type
= TREE_TYPE (t
);
821 switch (TREE_CODE (t
))
824 if (TREE_UNSIGNED (type
))
827 /* Check that -CST will not overflow type. */
828 prec
= TYPE_PRECISION (type
);
829 if (prec
> HOST_BITS_PER_WIDE_INT
)
831 if (TREE_INT_CST_LOW (t
) != 0)
833 prec
-= HOST_BITS_PER_WIDE_INT
;
834 val
= TREE_INT_CST_HIGH (t
);
837 val
= TREE_INT_CST_LOW (t
);
838 if (prec
< HOST_BITS_PER_WIDE_INT
)
839 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
840 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
847 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
848 return ! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
;
851 if (TREE_UNSIGNED (TREE_TYPE (t
)))
857 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
858 return negate_expr_p (TREE_OPERAND (t
, 1))
859 || negate_expr_p (TREE_OPERAND (t
, 0));
868 /* Given T, an expression, return the negation of T. Allow for T to be
869 null, in which case return null. */
880 type
= TREE_TYPE (t
);
883 switch (TREE_CODE (t
))
886 if (! TREE_UNSIGNED (type
)
887 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
888 && ! TREE_OVERFLOW (tem
))
893 tem
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (t
)));
894 /* Two's complement FP formats, such as c4x, may overflow. */
895 if (! TREE_OVERFLOW (tem
))
896 return convert (type
, tem
);
900 return convert (type
, TREE_OPERAND (t
, 0));
903 /* - (A - B) -> B - A */
904 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
905 return convert (type
,
906 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
908 TREE_OPERAND (t
, 0))));
912 if (TREE_UNSIGNED (TREE_TYPE (t
)))
918 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t
))))
920 tem
= TREE_OPERAND (t
, 1);
921 if (negate_expr_p (tem
))
922 return convert (type
,
923 fold (build (TREE_CODE (t
), TREE_TYPE (t
),
925 negate_expr (tem
))));
926 tem
= TREE_OPERAND (t
, 0);
927 if (negate_expr_p (tem
))
928 return convert (type
,
929 fold (build (TREE_CODE (t
), TREE_TYPE (t
),
931 TREE_OPERAND (t
, 1))));
939 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
942 /* Split a tree IN into a constant, literal and variable parts that could be
943 combined with CODE to make IN. "constant" means an expression with
944 TREE_CONSTANT but that isn't an actual constant. CODE must be a
945 commutative arithmetic operation. Store the constant part into *CONP,
946 the literal in *LITP and return the variable part. If a part isn't
947 present, set it to null. If the tree does not decompose in this way,
948 return the entire tree as the variable part and the other parts as null.
950 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
951 case, we negate an operand that was subtracted. Except if it is a
952 literal for which we use *MINUS_LITP instead.
954 If NEGATE_P is true, we are negating all of IN, again except a literal
955 for which we use *MINUS_LITP instead.
957 If IN is itself a literal or constant, return it as appropriate.
959 Note that we do not guarantee that any of the three values will be the
960 same type as IN, but they will have the same signedness and mode. */
963 split_tree (tree in
, enum tree_code code
, tree
*conp
, tree
*litp
,
964 tree
*minus_litp
, int negate_p
)
972 /* Strip any conversions that don't change the machine mode or signedness. */
973 STRIP_SIGN_NOPS (in
);
975 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
977 else if (TREE_CODE (in
) == code
978 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
979 /* We can associate addition and subtraction together (even
980 though the C standard doesn't say so) for integers because
981 the value is not affected. For reals, the value might be
982 affected, so we can't. */
983 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
984 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
986 tree op0
= TREE_OPERAND (in
, 0);
987 tree op1
= TREE_OPERAND (in
, 1);
988 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
989 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
991 /* First see if either of the operands is a literal, then a constant. */
992 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
993 *litp
= op0
, op0
= 0;
994 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
995 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
997 if (op0
!= 0 && TREE_CONSTANT (op0
))
998 *conp
= op0
, op0
= 0;
999 else if (op1
!= 0 && TREE_CONSTANT (op1
))
1000 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
1002 /* If we haven't dealt with either operand, this is not a case we can
1003 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1004 if (op0
!= 0 && op1
!= 0)
1009 var
= op1
, neg_var_p
= neg1_p
;
1011 /* Now do any needed negations. */
1013 *minus_litp
= *litp
, *litp
= 0;
1015 *conp
= negate_expr (*conp
);
1017 var
= negate_expr (var
);
1019 else if (TREE_CONSTANT (in
))
1027 *minus_litp
= *litp
, *litp
= 0;
1028 else if (*minus_litp
)
1029 *litp
= *minus_litp
, *minus_litp
= 0;
1030 *conp
= negate_expr (*conp
);
1031 var
= negate_expr (var
);
1037 /* Re-associate trees split by the above function. T1 and T2 are either
1038 expressions to associate or null. Return the new expression, if any. If
1039 we build an operation, do it in TYPE and with CODE. */
1042 associate_trees (tree t1
, tree t2
, enum tree_code code
, tree type
)
1049 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1050 try to fold this since we will have infinite recursion. But do
1051 deal with any NEGATE_EXPRs. */
1052 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1053 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1055 if (code
== PLUS_EXPR
)
1057 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1058 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1059 convert (type
, TREE_OPERAND (t1
, 0)));
1060 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1061 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1062 convert (type
, TREE_OPERAND (t2
, 0)));
1064 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1067 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1070 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1071 to produce a new constant.
1073 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1076 int_const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1078 unsigned HOST_WIDE_INT int1l
, int2l
;
1079 HOST_WIDE_INT int1h
, int2h
;
1080 unsigned HOST_WIDE_INT low
;
1082 unsigned HOST_WIDE_INT garbagel
;
1083 HOST_WIDE_INT garbageh
;
1085 tree type
= TREE_TYPE (arg1
);
1086 int uns
= TREE_UNSIGNED (type
);
1088 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1090 int no_overflow
= 0;
1092 int1l
= TREE_INT_CST_LOW (arg1
);
1093 int1h
= TREE_INT_CST_HIGH (arg1
);
1094 int2l
= TREE_INT_CST_LOW (arg2
);
1095 int2h
= TREE_INT_CST_HIGH (arg2
);
1100 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1104 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1108 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1111 case BIT_ANDTC_EXPR
:
1112 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1118 /* It's unclear from the C standard whether shifts can overflow.
1119 The following code ignores overflow; perhaps a C standard
1120 interpretation ruling is needed. */
1121 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1129 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1134 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1138 neg_double (int2l
, int2h
, &low
, &hi
);
1139 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1140 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1144 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1147 case TRUNC_DIV_EXPR
:
1148 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1149 case EXACT_DIV_EXPR
:
1150 /* This is a shortcut for a common special case. */
1151 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1152 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1153 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1154 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1156 if (code
== CEIL_DIV_EXPR
)
1159 low
= int1l
/ int2l
, hi
= 0;
1163 /* ... fall through ... */
1165 case ROUND_DIV_EXPR
:
1166 if (int2h
== 0 && int2l
== 1)
1168 low
= int1l
, hi
= int1h
;
1171 if (int1l
== int2l
&& int1h
== int2h
1172 && ! (int1l
== 0 && int1h
== 0))
1177 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1178 &low
, &hi
, &garbagel
, &garbageh
);
1181 case TRUNC_MOD_EXPR
:
1182 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1183 /* This is a shortcut for a common special case. */
1184 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1185 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1186 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1187 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1189 if (code
== CEIL_MOD_EXPR
)
1191 low
= int1l
% int2l
, hi
= 0;
1195 /* ... fall through ... */
1197 case ROUND_MOD_EXPR
:
1198 overflow
= div_and_round_double (code
, uns
,
1199 int1l
, int1h
, int2l
, int2h
,
1200 &garbagel
, &garbageh
, &low
, &hi
);
1206 low
= (((unsigned HOST_WIDE_INT
) int1h
1207 < (unsigned HOST_WIDE_INT
) int2h
)
1208 || (((unsigned HOST_WIDE_INT
) int1h
1209 == (unsigned HOST_WIDE_INT
) int2h
)
1212 low
= (int1h
< int2h
1213 || (int1h
== int2h
&& int1l
< int2l
));
1215 if (low
== (code
== MIN_EXPR
))
1216 low
= int1l
, hi
= int1h
;
1218 low
= int2l
, hi
= int2h
;
1225 /* If this is for a sizetype, can be represented as one (signed)
1226 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1229 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1230 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1231 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1232 return size_int_type_wide (low
, type
);
1235 t
= build_int_2 (low
, hi
);
1236 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1241 ? (!uns
|| is_sizetype
) && overflow
1242 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1244 | TREE_OVERFLOW (arg1
)
1245 | TREE_OVERFLOW (arg2
));
1247 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1248 So check if force_fit_type truncated the value. */
1250 && ! TREE_OVERFLOW (t
)
1251 && (TREE_INT_CST_HIGH (t
) != hi
1252 || TREE_INT_CST_LOW (t
) != low
))
1253 TREE_OVERFLOW (t
) = 1;
1255 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1256 | TREE_CONSTANT_OVERFLOW (arg1
)
1257 | TREE_CONSTANT_OVERFLOW (arg2
));
1261 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1262 constant. We assume ARG1 and ARG2 have the same data type, or at least
1263 are the same kind of constant and the same machine mode.
1265 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1268 const_binop (enum tree_code code
, tree arg1
, tree arg2
, int notrunc
)
1273 if (TREE_CODE (arg1
) == INTEGER_CST
)
1274 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1276 if (TREE_CODE (arg1
) == REAL_CST
)
1278 enum machine_mode mode
;
1281 REAL_VALUE_TYPE value
;
1284 d1
= TREE_REAL_CST (arg1
);
1285 d2
= TREE_REAL_CST (arg2
);
1287 type
= TREE_TYPE (arg1
);
1288 mode
= TYPE_MODE (type
);
1290 /* Don't perform operation if we honor signaling NaNs and
1291 either operand is a NaN. */
1292 if (HONOR_SNANS (mode
)
1293 && (REAL_VALUE_ISNAN (d1
) || REAL_VALUE_ISNAN (d2
)))
1296 /* Don't perform operation if it would raise a division
1297 by zero exception. */
1298 if (code
== RDIV_EXPR
1299 && REAL_VALUES_EQUAL (d2
, dconst0
)
1300 && (flag_trapping_math
|| ! MODE_HAS_INFINITIES (mode
)))
1303 /* If either operand is a NaN, just return it. Otherwise, set up
1304 for floating-point trap; we return an overflow. */
1305 if (REAL_VALUE_ISNAN (d1
))
1307 else if (REAL_VALUE_ISNAN (d2
))
1310 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1312 t
= build_real (type
, real_value_truncate (mode
, value
));
1315 = (force_fit_type (t
, 0)
1316 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1317 TREE_CONSTANT_OVERFLOW (t
)
1319 | TREE_CONSTANT_OVERFLOW (arg1
)
1320 | TREE_CONSTANT_OVERFLOW (arg2
);
1323 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1325 tree type
= TREE_TYPE (arg1
);
1326 tree r1
= TREE_REALPART (arg1
);
1327 tree i1
= TREE_IMAGPART (arg1
);
1328 tree r2
= TREE_REALPART (arg2
);
1329 tree i2
= TREE_IMAGPART (arg2
);
1335 t
= build_complex (type
,
1336 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1337 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1341 t
= build_complex (type
,
1342 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1343 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1347 t
= build_complex (type
,
1348 const_binop (MINUS_EXPR
,
1349 const_binop (MULT_EXPR
,
1351 const_binop (MULT_EXPR
,
1354 const_binop (PLUS_EXPR
,
1355 const_binop (MULT_EXPR
,
1357 const_binop (MULT_EXPR
,
1365 = const_binop (PLUS_EXPR
,
1366 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1367 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1370 t
= build_complex (type
,
1372 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1373 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1374 const_binop (PLUS_EXPR
,
1375 const_binop (MULT_EXPR
, r1
, r2
,
1377 const_binop (MULT_EXPR
, i1
, i2
,
1380 magsquared
, notrunc
),
1382 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1383 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1384 const_binop (MINUS_EXPR
,
1385 const_binop (MULT_EXPR
, i1
, r2
,
1387 const_binop (MULT_EXPR
, r1
, i2
,
1390 magsquared
, notrunc
));
1402 /* These are the hash table functions for the hash table of INTEGER_CST
1403 nodes of a sizetype. */
1405 /* Return the hash code code X, an INTEGER_CST. */
1408 size_htab_hash (const void *x
)
1412 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1413 ^ htab_hash_pointer (TREE_TYPE (t
))
1414 ^ (TREE_OVERFLOW (t
) << 20));
1417 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1418 is the same as that given by *Y, which is the same. */
1421 size_htab_eq (const void *x
, const void *y
)
1426 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1427 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1428 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1429 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1432 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1433 bits are given by NUMBER and of the sizetype represented by KIND. */
1436 size_int_wide (HOST_WIDE_INT number
, enum size_type_kind kind
)
1438 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1441 /* Likewise, but the desired type is specified explicitly. */
1443 static GTY (()) tree new_const
;
1444 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1448 size_int_type_wide (HOST_WIDE_INT number
, tree type
)
1454 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1455 new_const
= make_node (INTEGER_CST
);
1458 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1459 hash table, we return the value from the hash table. Otherwise, we
1460 place that in the hash table and make a new node for the next time. */
1461 TREE_INT_CST_LOW (new_const
) = number
;
1462 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1463 TREE_TYPE (new_const
) = type
;
1464 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1465 = force_fit_type (new_const
, 0);
1467 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1473 new_const
= make_node (INTEGER_CST
);
1477 return (tree
) *slot
;
1480 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1481 is a tree code. The type of the result is taken from the operands.
1482 Both must be the same type integer type and it must be a size type.
1483 If the operands are constant, so is the result. */
1486 size_binop (enum tree_code code
, tree arg0
, tree arg1
)
1488 tree type
= TREE_TYPE (arg0
);
1490 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1491 || type
!= TREE_TYPE (arg1
))
1494 /* Handle the special case of two integer constants faster. */
1495 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1497 /* And some specific cases even faster than that. */
1498 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1500 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1501 && integer_zerop (arg1
))
1503 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1506 /* Handle general case of two integer constants. */
1507 return int_const_binop (code
, arg0
, arg1
, 0);
1510 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1511 return error_mark_node
;
1513 return fold (build (code
, type
, arg0
, arg1
));
1516 /* Given two values, either both of sizetype or both of bitsizetype,
1517 compute the difference between the two values. Return the value
1518 in signed type corresponding to the type of the operands. */
1521 size_diffop (tree arg0
, tree arg1
)
1523 tree type
= TREE_TYPE (arg0
);
1526 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1527 || type
!= TREE_TYPE (arg1
))
1530 /* If the type is already signed, just do the simple thing. */
1531 if (! TREE_UNSIGNED (type
))
1532 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1534 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
1535 ? sbitsizetype
: ssizetype
);
1537 /* If either operand is not a constant, do the conversions to the signed
1538 type and subtract. The hardware will do the right thing with any
1539 overflow in the subtraction. */
1540 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1541 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
1542 convert (ctype
, arg1
));
1544 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1545 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1546 overflow) and negate (which can't either). Special-case a result
1547 of zero while we're here. */
1548 if (tree_int_cst_equal (arg0
, arg1
))
1549 return convert (ctype
, integer_zero_node
);
1550 else if (tree_int_cst_lt (arg1
, arg0
))
1551 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1553 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
1554 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
1558 /* Given T, a tree representing type conversion of ARG1, a constant,
1559 return a constant tree representing the result of conversion. */
1562 fold_convert (tree t
, tree arg1
)
1564 tree type
= TREE_TYPE (t
);
1567 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1569 if (TREE_CODE (arg1
) == INTEGER_CST
)
1571 /* If we would build a constant wider than GCC supports,
1572 leave the conversion unfolded. */
1573 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1576 /* If we are trying to make a sizetype for a small integer, use
1577 size_int to pick up cached types to reduce duplicate nodes. */
1578 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1579 && !TREE_CONSTANT_OVERFLOW (arg1
)
1580 && compare_tree_int (arg1
, 10000) < 0)
1581 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1583 /* Given an integer constant, make new constant with new type,
1584 appropriately sign-extended or truncated. */
1585 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1586 TREE_INT_CST_HIGH (arg1
));
1587 TREE_TYPE (t
) = type
;
1588 /* Indicate an overflow if (1) ARG1 already overflowed,
1589 or (2) force_fit_type indicates an overflow.
1590 Tell force_fit_type that an overflow has already occurred
1591 if ARG1 is a too-large unsigned value and T is signed.
1592 But don't indicate an overflow if converting a pointer. */
1594 = ((force_fit_type (t
,
1595 (TREE_INT_CST_HIGH (arg1
) < 0
1596 && (TREE_UNSIGNED (type
)
1597 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1598 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1599 || TREE_OVERFLOW (arg1
));
1600 TREE_CONSTANT_OVERFLOW (t
)
1601 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1603 else if (TREE_CODE (arg1
) == REAL_CST
)
1605 /* Don't initialize these, use assignments.
1606 Initialized local aggregates don't work on old compilers. */
1610 tree type1
= TREE_TYPE (arg1
);
1613 x
= TREE_REAL_CST (arg1
);
1614 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1616 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1617 if (!no_upper_bound
)
1618 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1620 /* See if X will be in range after truncation towards 0.
1621 To compensate for truncation, move the bounds away from 0,
1622 but reject if X exactly equals the adjusted bounds. */
1623 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1624 if (!no_upper_bound
)
1625 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1626 /* If X is a NaN, use zero instead and show we have an overflow.
1627 Otherwise, range check. */
1628 if (REAL_VALUE_ISNAN (x
))
1629 overflow
= 1, x
= dconst0
;
1630 else if (! (REAL_VALUES_LESS (l
, x
)
1632 && REAL_VALUES_LESS (x
, u
)))
1636 HOST_WIDE_INT low
, high
;
1637 REAL_VALUE_TO_INT (&low
, &high
, x
);
1638 t
= build_int_2 (low
, high
);
1640 TREE_TYPE (t
) = type
;
1642 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1643 TREE_CONSTANT_OVERFLOW (t
)
1644 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1646 TREE_TYPE (t
) = type
;
1648 else if (TREE_CODE (type
) == REAL_TYPE
)
1650 if (TREE_CODE (arg1
) == INTEGER_CST
)
1651 return build_real_from_int_cst (type
, arg1
);
1652 if (TREE_CODE (arg1
) == REAL_CST
)
1654 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1656 /* We make a copy of ARG1 so that we don't modify an
1657 existing constant tree. */
1658 t
= copy_node (arg1
);
1659 TREE_TYPE (t
) = type
;
1663 t
= build_real (type
,
1664 real_value_truncate (TYPE_MODE (type
),
1665 TREE_REAL_CST (arg1
)));
1668 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1669 TREE_CONSTANT_OVERFLOW (t
)
1670 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1674 TREE_CONSTANT (t
) = 1;
1678 /* Return an expr equal to X but certainly not valid as an lvalue. */
1685 /* These things are certainly not lvalues. */
1686 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1687 || TREE_CODE (x
) == INTEGER_CST
1688 || TREE_CODE (x
) == REAL_CST
1689 || TREE_CODE (x
) == STRING_CST
1690 || TREE_CODE (x
) == ADDR_EXPR
)
1693 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1694 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1698 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1699 Zero means allow extended lvalues. */
1701 int pedantic_lvalues
;
1703 /* When pedantic, return an expr equal to X but certainly not valid as a
1704 pedantic lvalue. Otherwise, return X. */
1707 pedantic_non_lvalue (tree x
)
1709 if (pedantic_lvalues
)
1710 return non_lvalue (x
);
1715 /* Given a tree comparison code, return the code that is the logical inverse
1716 of the given code. It is not safe to do this for floating-point
1717 comparisons, except for NE_EXPR and EQ_EXPR. */
1719 static enum tree_code
1720 invert_tree_comparison (enum tree_code code
)
1741 /* Similar, but return the comparison that results if the operands are
1742 swapped. This is safe for floating-point. */
1744 static enum tree_code
1745 swap_tree_comparison (enum tree_code code
)
1766 /* Convert a comparison tree code from an enum tree_code representation
1767 into a compcode bit-based encoding. This function is the inverse of
1768 compcode_to_comparison. */
1771 comparison_to_compcode (enum tree_code code
)
1792 /* Convert a compcode bit-based encoding of a comparison operator back
1793 to GCC's enum tree_code representation. This function is the
1794 inverse of comparison_to_compcode. */
1796 static enum tree_code
1797 compcode_to_comparison (int code
)
1818 /* Return nonzero if CODE is a tree code that represents a truth value. */
1821 truth_value_p (enum tree_code code
)
1823 return (TREE_CODE_CLASS (code
) == '<'
1824 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
1825 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
1826 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
1829 /* Return nonzero if two operands are necessarily equal.
1830 If ONLY_CONST is nonzero, only return nonzero for constants.
1831 This function tests whether the operands are indistinguishable;
1832 it does not test whether they are equal using C's == operation.
1833 The distinction is important for IEEE floating point, because
1834 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1835 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1838 operand_equal_p (tree arg0
, tree arg1
, int only_const
)
1842 /* If both types don't have the same signedness, then we can't consider
1843 them equal. We must check this before the STRIP_NOPS calls
1844 because they may change the signedness of the arguments. */
1845 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
1851 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
1852 /* This is needed for conversions and for COMPONENT_REF.
1853 Might as well play it safe and always test this. */
1854 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
1855 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
1856 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
1859 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1860 We don't care about side effects in that case because the SAVE_EXPR
1861 takes care of that for us. In all other cases, two expressions are
1862 equal if they have no side effects. If we have two identical
1863 expressions with side effects that should be treated the same due
1864 to the only side effects being identical SAVE_EXPR's, that will
1865 be detected in the recursive calls below. */
1866 if (arg0
== arg1
&& ! only_const
1867 && (TREE_CODE (arg0
) == SAVE_EXPR
1868 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
1871 /* Next handle constant cases, those for which we can return 1 even
1872 if ONLY_CONST is set. */
1873 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
1874 switch (TREE_CODE (arg0
))
1877 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1878 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1879 && tree_int_cst_equal (arg0
, arg1
));
1882 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1883 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1884 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
1885 TREE_REAL_CST (arg1
)));
1891 if (TREE_CONSTANT_OVERFLOW (arg0
)
1892 || TREE_CONSTANT_OVERFLOW (arg1
))
1895 v1
= TREE_VECTOR_CST_ELTS (arg0
);
1896 v2
= TREE_VECTOR_CST_ELTS (arg1
);
1899 if (!operand_equal_p (v1
, v2
, only_const
))
1901 v1
= TREE_CHAIN (v1
);
1902 v2
= TREE_CHAIN (v2
);
1909 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
1911 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
1915 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
1916 && ! memcmp (TREE_STRING_POINTER (arg0
),
1917 TREE_STRING_POINTER (arg1
),
1918 TREE_STRING_LENGTH (arg0
)));
1921 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
1930 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
1933 /* Two conversions are equal only if signedness and modes match. */
1934 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
1935 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
1936 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
1939 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1940 TREE_OPERAND (arg1
, 0), 0);
1944 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
1945 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
1949 /* For commutative ops, allow the other order. */
1950 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
1951 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
1952 || TREE_CODE (arg0
) == BIT_IOR_EXPR
1953 || TREE_CODE (arg0
) == BIT_XOR_EXPR
1954 || TREE_CODE (arg0
) == BIT_AND_EXPR
1955 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
1956 && operand_equal_p (TREE_OPERAND (arg0
, 0),
1957 TREE_OPERAND (arg1
, 1), 0)
1958 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1959 TREE_OPERAND (arg1
, 0), 0));
1962 /* If either of the pointer (or reference) expressions we are
1963 dereferencing contain a side effect, these cannot be equal. */
1964 if (TREE_SIDE_EFFECTS (arg0
)
1965 || TREE_SIDE_EFFECTS (arg1
))
1968 switch (TREE_CODE (arg0
))
1971 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1972 TREE_OPERAND (arg1
, 0), 0);
1976 case ARRAY_RANGE_REF
:
1977 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1978 TREE_OPERAND (arg1
, 0), 0)
1979 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1980 TREE_OPERAND (arg1
, 1), 0));
1983 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1984 TREE_OPERAND (arg1
, 0), 0)
1985 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1986 TREE_OPERAND (arg1
, 1), 0)
1987 && operand_equal_p (TREE_OPERAND (arg0
, 2),
1988 TREE_OPERAND (arg1
, 2), 0));
1994 switch (TREE_CODE (arg0
))
1997 case TRUTH_NOT_EXPR
:
1998 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1999 TREE_OPERAND (arg1
, 0), 0);
2002 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2005 /* If the CALL_EXPRs call different functions, then they
2006 clearly can not be equal. */
2007 if (! operand_equal_p (TREE_OPERAND (arg0
, 0),
2008 TREE_OPERAND (arg1
, 0), 0))
2011 /* Only consider const functions equivalent. */
2012 fndecl
= get_callee_fndecl (arg0
);
2013 if (fndecl
== NULL_TREE
2014 || ! (flags_from_decl_or_type (fndecl
) & ECF_CONST
))
2017 /* Now see if all the arguments are the same. operand_equal_p
2018 does not handle TREE_LIST, so we walk the operands here
2019 feeding them to operand_equal_p. */
2020 arg0
= TREE_OPERAND (arg0
, 1);
2021 arg1
= TREE_OPERAND (arg1
, 1);
2022 while (arg0
&& arg1
)
2024 if (! operand_equal_p (TREE_VALUE (arg0
), TREE_VALUE (arg1
), 0))
2027 arg0
= TREE_CHAIN (arg0
);
2028 arg1
= TREE_CHAIN (arg1
);
2031 /* If we get here and both argument lists are exhausted
2032 then the CALL_EXPRs are equal. */
2033 return ! (arg0
|| arg1
);
2040 /* Consider __builtin_sqrt equal to sqrt. */
2041 return TREE_CODE (arg0
) == FUNCTION_DECL
2042 && DECL_BUILT_IN (arg0
) && DECL_BUILT_IN (arg1
)
2043 && DECL_BUILT_IN_CLASS (arg0
) == DECL_BUILT_IN_CLASS (arg1
)
2044 && DECL_FUNCTION_CODE (arg0
) == DECL_FUNCTION_CODE (arg1
);
2051 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2052 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2054 When in doubt, return 0. */
2057 operand_equal_for_comparison_p (tree arg0
, tree arg1
, tree other
)
2059 int unsignedp1
, unsignedpo
;
2060 tree primarg0
, primarg1
, primother
;
2061 unsigned int correct_width
;
2063 if (operand_equal_p (arg0
, arg1
, 0))
2066 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2067 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2070 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2071 and see if the inner values are the same. This removes any
2072 signedness comparison, which doesn't matter here. */
2073 primarg0
= arg0
, primarg1
= arg1
;
2074 STRIP_NOPS (primarg0
);
2075 STRIP_NOPS (primarg1
);
2076 if (operand_equal_p (primarg0
, primarg1
, 0))
2079 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2080 actual comparison operand, ARG0.
2082 First throw away any conversions to wider types
2083 already present in the operands. */
2085 primarg1
= get_narrower (arg1
, &unsignedp1
);
2086 primother
= get_narrower (other
, &unsignedpo
);
2088 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2089 if (unsignedp1
== unsignedpo
2090 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2091 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2093 tree type
= TREE_TYPE (arg0
);
2095 /* Make sure shorter operand is extended the right way
2096 to match the longer operand. */
2097 primarg1
= convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2098 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2100 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2107 /* See if ARG is an expression that is either a comparison or is performing
2108 arithmetic on comparisons. The comparisons must only be comparing
2109 two different values, which will be stored in *CVAL1 and *CVAL2; if
2110 they are nonzero it means that some operands have already been found.
2111 No variables may be used anywhere else in the expression except in the
2112 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2113 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2115 If this is true, return 1. Otherwise, return zero. */
2118 twoval_comparison_p (tree arg
, tree
*cval1
, tree
*cval2
, int *save_p
)
2120 enum tree_code code
= TREE_CODE (arg
);
2121 char class = TREE_CODE_CLASS (code
);
2123 /* We can handle some of the 'e' cases here. */
2124 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2126 else if (class == 'e'
2127 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2128 || code
== COMPOUND_EXPR
))
2131 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2132 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2134 /* If we've already found a CVAL1 or CVAL2, this expression is
2135 two complex to handle. */
2136 if (*cval1
|| *cval2
)
2146 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2149 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2150 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2151 cval1
, cval2
, save_p
));
2157 if (code
== COND_EXPR
)
2158 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2159 cval1
, cval2
, save_p
)
2160 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2161 cval1
, cval2
, save_p
)
2162 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2163 cval1
, cval2
, save_p
));
2167 /* First see if we can handle the first operand, then the second. For
2168 the second operand, we know *CVAL1 can't be zero. It must be that
2169 one side of the comparison is each of the values; test for the
2170 case where this isn't true by failing if the two operands
2173 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2174 TREE_OPERAND (arg
, 1), 0))
2178 *cval1
= TREE_OPERAND (arg
, 0);
2179 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2181 else if (*cval2
== 0)
2182 *cval2
= TREE_OPERAND (arg
, 0);
2183 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2188 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2190 else if (*cval2
== 0)
2191 *cval2
= TREE_OPERAND (arg
, 1);
2192 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2204 /* ARG is a tree that is known to contain just arithmetic operations and
2205 comparisons. Evaluate the operations in the tree substituting NEW0 for
2206 any occurrence of OLD0 as an operand of a comparison and likewise for
2210 eval_subst (tree arg
, tree old0
, tree new0
, tree old1
, tree new1
)
2212 tree type
= TREE_TYPE (arg
);
2213 enum tree_code code
= TREE_CODE (arg
);
2214 char class = TREE_CODE_CLASS (code
);
2216 /* We can handle some of the 'e' cases here. */
2217 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2219 else if (class == 'e'
2220 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2226 return fold (build1 (code
, type
,
2227 eval_subst (TREE_OPERAND (arg
, 0),
2228 old0
, new0
, old1
, new1
)));
2231 return fold (build (code
, type
,
2232 eval_subst (TREE_OPERAND (arg
, 0),
2233 old0
, new0
, old1
, new1
),
2234 eval_subst (TREE_OPERAND (arg
, 1),
2235 old0
, new0
, old1
, new1
)));
2241 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2244 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2247 return fold (build (code
, type
,
2248 eval_subst (TREE_OPERAND (arg
, 0),
2249 old0
, new0
, old1
, new1
),
2250 eval_subst (TREE_OPERAND (arg
, 1),
2251 old0
, new0
, old1
, new1
),
2252 eval_subst (TREE_OPERAND (arg
, 2),
2253 old0
, new0
, old1
, new1
)));
2257 /* Fall through - ??? */
2261 tree arg0
= TREE_OPERAND (arg
, 0);
2262 tree arg1
= TREE_OPERAND (arg
, 1);
2264 /* We need to check both for exact equality and tree equality. The
2265 former will be true if the operand has a side-effect. In that
2266 case, we know the operand occurred exactly once. */
2268 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2270 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2273 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2275 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2278 return fold (build (code
, type
, arg0
, arg1
));
2286 /* Return a tree for the case when the result of an expression is RESULT
2287 converted to TYPE and OMITTED was previously an operand of the expression
2288 but is now not needed (e.g., we folded OMITTED * 0).
2290 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2291 the conversion of RESULT to TYPE. */
2294 omit_one_operand (tree type
, tree result
, tree omitted
)
2296 tree t
= convert (type
, result
);
2298 if (TREE_SIDE_EFFECTS (omitted
))
2299 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2301 return non_lvalue (t
);
2304 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2307 pedantic_omit_one_operand (tree type
, tree result
, tree omitted
)
2309 tree t
= convert (type
, result
);
2311 if (TREE_SIDE_EFFECTS (omitted
))
2312 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2314 return pedantic_non_lvalue (t
);
2317 /* Return a simplified tree node for the truth-negation of ARG. This
2318 never alters ARG itself. We assume that ARG is an operation that
2319 returns a truth value (0 or 1). */
2322 invert_truthvalue (tree arg
)
2324 tree type
= TREE_TYPE (arg
);
2325 enum tree_code code
= TREE_CODE (arg
);
2327 if (code
== ERROR_MARK
)
2330 /* If this is a comparison, we can simply invert it, except for
2331 floating-point non-equality comparisons, in which case we just
2332 enclose a TRUTH_NOT_EXPR around what we have. */
2334 if (TREE_CODE_CLASS (code
) == '<')
2336 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2337 && !flag_unsafe_math_optimizations
2340 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2342 return build (invert_tree_comparison (code
), type
,
2343 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2349 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2351 case TRUTH_AND_EXPR
:
2352 return build (TRUTH_OR_EXPR
, type
,
2353 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2354 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2357 return build (TRUTH_AND_EXPR
, type
,
2358 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2359 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2361 case TRUTH_XOR_EXPR
:
2362 /* Here we can invert either operand. We invert the first operand
2363 unless the second operand is a TRUTH_NOT_EXPR in which case our
2364 result is the XOR of the first operand with the inside of the
2365 negation of the second operand. */
2367 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2368 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2369 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2371 return build (TRUTH_XOR_EXPR
, type
,
2372 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2373 TREE_OPERAND (arg
, 1));
2375 case TRUTH_ANDIF_EXPR
:
2376 return build (TRUTH_ORIF_EXPR
, type
,
2377 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2378 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2380 case TRUTH_ORIF_EXPR
:
2381 return build (TRUTH_ANDIF_EXPR
, type
,
2382 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2383 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2385 case TRUTH_NOT_EXPR
:
2386 return TREE_OPERAND (arg
, 0);
2389 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2390 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2391 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2394 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2395 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2397 case WITH_RECORD_EXPR
:
2398 return build (WITH_RECORD_EXPR
, type
,
2399 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2400 TREE_OPERAND (arg
, 1));
2402 case NON_LVALUE_EXPR
:
2403 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2408 return build1 (TREE_CODE (arg
), type
,
2409 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2412 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2414 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2417 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2419 case CLEANUP_POINT_EXPR
:
2420 return build1 (CLEANUP_POINT_EXPR
, type
,
2421 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2426 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2428 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2431 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2432 operands are another bit-wise operation with a common input. If so,
2433 distribute the bit operations to save an operation and possibly two if
2434 constants are involved. For example, convert
2435 (A | B) & (A | C) into A | (B & C)
2436 Further simplification will occur if B and C are constants.
2438 If this optimization cannot be done, 0 will be returned. */
2441 distribute_bit_expr (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
2446 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2447 || TREE_CODE (arg0
) == code
2448 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2449 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2452 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2454 common
= TREE_OPERAND (arg0
, 0);
2455 left
= TREE_OPERAND (arg0
, 1);
2456 right
= TREE_OPERAND (arg1
, 1);
2458 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2460 common
= TREE_OPERAND (arg0
, 0);
2461 left
= TREE_OPERAND (arg0
, 1);
2462 right
= TREE_OPERAND (arg1
, 0);
2464 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2466 common
= TREE_OPERAND (arg0
, 1);
2467 left
= TREE_OPERAND (arg0
, 0);
2468 right
= TREE_OPERAND (arg1
, 1);
2470 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2472 common
= TREE_OPERAND (arg0
, 1);
2473 left
= TREE_OPERAND (arg0
, 0);
2474 right
= TREE_OPERAND (arg1
, 0);
2479 return fold (build (TREE_CODE (arg0
), type
, common
,
2480 fold (build (code
, type
, left
, right
))));
2483 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2484 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2487 make_bit_field_ref (tree inner
, tree type
, int bitsize
, int bitpos
,
2490 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2491 size_int (bitsize
), bitsize_int (bitpos
));
2493 TREE_UNSIGNED (result
) = unsignedp
;
2498 /* Optimize a bit-field compare.
2500 There are two cases: First is a compare against a constant and the
2501 second is a comparison of two items where the fields are at the same
2502 bit position relative to the start of a chunk (byte, halfword, word)
2503 large enough to contain it. In these cases we can avoid the shift
2504 implicit in bitfield extractions.
2506 For constants, we emit a compare of the shifted constant with the
2507 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2508 compared. For two fields at the same position, we do the ANDs with the
2509 similar mask and compare the result of the ANDs.
2511 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2512 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2513 are the left and right operands of the comparison, respectively.
2515 If the optimization described above can be done, we return the resulting
2516 tree. Otherwise we return zero. */
2519 optimize_bit_field_compare (enum tree_code code
, tree compare_type
,
2522 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2523 tree type
= TREE_TYPE (lhs
);
2524 tree signed_type
, unsigned_type
;
2525 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2526 enum machine_mode lmode
, rmode
, nmode
;
2527 int lunsignedp
, runsignedp
;
2528 int lvolatilep
= 0, rvolatilep
= 0;
2529 tree linner
, rinner
= NULL_TREE
;
2533 /* Get all the information about the extractions being done. If the bit size
2534 if the same as the size of the underlying object, we aren't doing an
2535 extraction at all and so can do nothing. We also don't want to
2536 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2537 then will no longer be able to replace it. */
2538 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2539 &lunsignedp
, &lvolatilep
);
2540 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2541 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2546 /* If this is not a constant, we can only do something if bit positions,
2547 sizes, and signedness are the same. */
2548 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2549 &runsignedp
, &rvolatilep
);
2551 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2552 || lunsignedp
!= runsignedp
|| offset
!= 0
2553 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2557 /* See if we can find a mode to refer to this field. We should be able to,
2558 but fail if we can't. */
2559 nmode
= get_best_mode (lbitsize
, lbitpos
,
2560 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2561 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2562 TYPE_ALIGN (TREE_TYPE (rinner
))),
2563 word_mode
, lvolatilep
|| rvolatilep
);
2564 if (nmode
== VOIDmode
)
2567 /* Set signed and unsigned types of the precision of this mode for the
2569 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2570 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2572 /* Compute the bit position and size for the new reference and our offset
2573 within it. If the new reference is the same size as the original, we
2574 won't optimize anything, so return zero. */
2575 nbitsize
= GET_MODE_BITSIZE (nmode
);
2576 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2578 if (nbitsize
== lbitsize
)
2581 if (BYTES_BIG_ENDIAN
)
2582 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2584 /* Make the mask to be used against the extracted field. */
2585 mask
= build_int_2 (~0, ~0);
2586 TREE_TYPE (mask
) = unsigned_type
;
2587 force_fit_type (mask
, 0);
2588 mask
= convert (unsigned_type
, mask
);
2589 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2590 mask
= const_binop (RSHIFT_EXPR
, mask
,
2591 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2594 /* If not comparing with constant, just rework the comparison
2596 return build (code
, compare_type
,
2597 build (BIT_AND_EXPR
, unsigned_type
,
2598 make_bit_field_ref (linner
, unsigned_type
,
2599 nbitsize
, nbitpos
, 1),
2601 build (BIT_AND_EXPR
, unsigned_type
,
2602 make_bit_field_ref (rinner
, unsigned_type
,
2603 nbitsize
, nbitpos
, 1),
2606 /* Otherwise, we are handling the constant case. See if the constant is too
2607 big for the field. Warn and return a tree of for 0 (false) if so. We do
2608 this not only for its own sake, but to avoid having to test for this
2609 error case below. If we didn't, we might generate wrong code.
2611 For unsigned fields, the constant shifted right by the field length should
2612 be all zero. For signed fields, the high-order bits should agree with
2617 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2618 convert (unsigned_type
, rhs
),
2619 size_int (lbitsize
), 0)))
2621 warning ("comparison is always %d due to width of bit-field",
2623 return convert (compare_type
,
2625 ? integer_one_node
: integer_zero_node
));
2630 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2631 size_int (lbitsize
- 1), 0);
2632 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2634 warning ("comparison is always %d due to width of bit-field",
2636 return convert (compare_type
,
2638 ? integer_one_node
: integer_zero_node
));
2642 /* Single-bit compares should always be against zero. */
2643 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2645 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2646 rhs
= convert (type
, integer_zero_node
);
2649 /* Make a new bitfield reference, shift the constant over the
2650 appropriate number of bits and mask it with the computed mask
2651 (in case this was a signed field). If we changed it, make a new one. */
2652 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2655 TREE_SIDE_EFFECTS (lhs
) = 1;
2656 TREE_THIS_VOLATILE (lhs
) = 1;
2659 rhs
= fold (const_binop (BIT_AND_EXPR
,
2660 const_binop (LSHIFT_EXPR
,
2661 convert (unsigned_type
, rhs
),
2662 size_int (lbitpos
), 0),
2665 return build (code
, compare_type
,
2666 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2670 /* Subroutine for fold_truthop: decode a field reference.
2672 If EXP is a comparison reference, we return the innermost reference.
2674 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2675 set to the starting bit number.
2677 If the innermost field can be completely contained in a mode-sized
2678 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2680 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2681 otherwise it is not changed.
2683 *PUNSIGNEDP is set to the signedness of the field.
2685 *PMASK is set to the mask used. This is either contained in a
2686 BIT_AND_EXPR or derived from the width of the field.
2688 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2690 Return 0 if this is not a component reference or is one that we can't
2691 do anything with. */
2694 decode_field_reference (tree exp
, HOST_WIDE_INT
*pbitsize
,
2695 HOST_WIDE_INT
*pbitpos
, enum machine_mode
*pmode
,
2696 int *punsignedp
, int *pvolatilep
,
2697 tree
*pmask
, tree
*pand_mask
)
2699 tree outer_type
= 0;
2701 tree mask
, inner
, offset
;
2703 unsigned int precision
;
2705 /* All the optimizations using this function assume integer fields.
2706 There are problems with FP fields since the type_for_size call
2707 below can fail for, e.g., XFmode. */
2708 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
2711 /* We are interested in the bare arrangement of bits, so strip everything
2712 that doesn't affect the machine mode. However, record the type of the
2713 outermost expression if it may matter below. */
2714 if (TREE_CODE (exp
) == NOP_EXPR
2715 || TREE_CODE (exp
) == CONVERT_EXPR
2716 || TREE_CODE (exp
) == NON_LVALUE_EXPR
)
2717 outer_type
= TREE_TYPE (exp
);
2720 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
2722 and_mask
= TREE_OPERAND (exp
, 1);
2723 exp
= TREE_OPERAND (exp
, 0);
2724 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
2725 if (TREE_CODE (and_mask
) != INTEGER_CST
)
2729 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
2730 punsignedp
, pvolatilep
);
2731 if ((inner
== exp
&& and_mask
== 0)
2732 || *pbitsize
< 0 || offset
!= 0
2733 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
2736 /* If the number of bits in the reference is the same as the bitsize of
2737 the outer type, then the outer type gives the signedness. Otherwise
2738 (in case of a small bitfield) the signedness is unchanged. */
2739 if (outer_type
&& *pbitsize
== tree_low_cst (TYPE_SIZE (outer_type
), 1))
2740 *punsignedp
= TREE_UNSIGNED (outer_type
);
2742 /* Compute the mask to access the bitfield. */
2743 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
2744 precision
= TYPE_PRECISION (unsigned_type
);
2746 mask
= build_int_2 (~0, ~0);
2747 TREE_TYPE (mask
) = unsigned_type
;
2748 force_fit_type (mask
, 0);
2749 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2750 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2752 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2754 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
2755 convert (unsigned_type
, and_mask
), mask
));
2758 *pand_mask
= and_mask
;
2762 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2766 all_ones_mask_p (tree mask
, int size
)
2768 tree type
= TREE_TYPE (mask
);
2769 unsigned int precision
= TYPE_PRECISION (type
);
2772 tmask
= build_int_2 (~0, ~0);
2773 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
2774 force_fit_type (tmask
, 0);
2776 tree_int_cst_equal (mask
,
2777 const_binop (RSHIFT_EXPR
,
2778 const_binop (LSHIFT_EXPR
, tmask
,
2779 size_int (precision
- size
),
2781 size_int (precision
- size
), 0));
2784 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2785 represents the sign bit of EXP's type. If EXP represents a sign
2786 or zero extension, also test VAL against the unextended type.
2787 The return value is the (sub)expression whose sign bit is VAL,
2788 or NULL_TREE otherwise. */
2791 sign_bit_p (tree exp
, tree val
)
2793 unsigned HOST_WIDE_INT mask_lo
, lo
;
2794 HOST_WIDE_INT mask_hi
, hi
;
2798 /* Tree EXP must have an integral type. */
2799 t
= TREE_TYPE (exp
);
2800 if (! INTEGRAL_TYPE_P (t
))
2803 /* Tree VAL must be an integer constant. */
2804 if (TREE_CODE (val
) != INTEGER_CST
2805 || TREE_CONSTANT_OVERFLOW (val
))
2808 width
= TYPE_PRECISION (t
);
2809 if (width
> HOST_BITS_PER_WIDE_INT
)
2811 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
2814 mask_hi
= ((unsigned HOST_WIDE_INT
) -1
2815 >> (2 * HOST_BITS_PER_WIDE_INT
- width
));
2821 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
2824 mask_lo
= ((unsigned HOST_WIDE_INT
) -1
2825 >> (HOST_BITS_PER_WIDE_INT
- width
));
2828 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
2829 treat VAL as if it were unsigned. */
2830 if ((TREE_INT_CST_HIGH (val
) & mask_hi
) == hi
2831 && (TREE_INT_CST_LOW (val
) & mask_lo
) == lo
)
2834 /* Handle extension from a narrower type. */
2835 if (TREE_CODE (exp
) == NOP_EXPR
2836 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
2837 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
2842 /* Subroutine for fold_truthop: determine if an operand is simple enough
2843 to be evaluated unconditionally. */
2846 simple_operand_p (tree exp
)
2848 /* Strip any conversions that don't change the machine mode. */
2849 while ((TREE_CODE (exp
) == NOP_EXPR
2850 || TREE_CODE (exp
) == CONVERT_EXPR
)
2851 && (TYPE_MODE (TREE_TYPE (exp
))
2852 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
2853 exp
= TREE_OPERAND (exp
, 0);
2855 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
2857 && ! TREE_ADDRESSABLE (exp
)
2858 && ! TREE_THIS_VOLATILE (exp
)
2859 && ! DECL_NONLOCAL (exp
)
2860 /* Don't regard global variables as simple. They may be
2861 allocated in ways unknown to the compiler (shared memory,
2862 #pragma weak, etc). */
2863 && ! TREE_PUBLIC (exp
)
2864 && ! DECL_EXTERNAL (exp
)
2865 /* Loading a static variable is unduly expensive, but global
2866 registers aren't expensive. */
2867 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
2870 /* The following functions are subroutines to fold_range_test and allow it to
2871 try to change a logical combination of comparisons into a range test.
2874 X == 2 || X == 3 || X == 4 || X == 5
2878 (unsigned) (X - 2) <= 3
2880 We describe each set of comparisons as being either inside or outside
2881 a range, using a variable named like IN_P, and then describe the
2882 range with a lower and upper bound. If one of the bounds is omitted,
2883 it represents either the highest or lowest value of the type.
2885 In the comments below, we represent a range by two numbers in brackets
2886 preceded by a "+" to designate being inside that range, or a "-" to
2887 designate being outside that range, so the condition can be inverted by
2888 flipping the prefix. An omitted bound is represented by a "-". For
2889 example, "- [-, 10]" means being outside the range starting at the lowest
2890 possible value and ending at 10, in other words, being greater than 10.
2891 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2894 We set up things so that the missing bounds are handled in a consistent
2895 manner so neither a missing bound nor "true" and "false" need to be
2896 handled using a special case. */
2898 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2899 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2900 and UPPER1_P are nonzero if the respective argument is an upper bound
2901 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2902 must be specified for a comparison. ARG1 will be converted to ARG0's
2903 type if both are specified. */
2906 range_binop (enum tree_code code
, tree type
, tree arg0
, int upper0_p
,
2907 tree arg1
, int upper1_p
)
2913 /* If neither arg represents infinity, do the normal operation.
2914 Else, if not a comparison, return infinity. Else handle the special
2915 comparison rules. Note that most of the cases below won't occur, but
2916 are handled for consistency. */
2918 if (arg0
!= 0 && arg1
!= 0)
2920 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
2921 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
2923 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
2926 if (TREE_CODE_CLASS (code
) != '<')
2929 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2930 for neither. In real maths, we cannot assume open ended ranges are
2931 the same. But, this is computer arithmetic, where numbers are finite.
2932 We can therefore make the transformation of any unbounded range with
2933 the value Z, Z being greater than any representable number. This permits
2934 us to treat unbounded ranges as equal. */
2935 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
2936 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
2940 result
= sgn0
== sgn1
;
2943 result
= sgn0
!= sgn1
;
2946 result
= sgn0
< sgn1
;
2949 result
= sgn0
<= sgn1
;
2952 result
= sgn0
> sgn1
;
2955 result
= sgn0
>= sgn1
;
2961 return convert (type
, result
? integer_one_node
: integer_zero_node
);
2964 /* Given EXP, a logical expression, set the range it is testing into
2965 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2966 actually being tested. *PLOW and *PHIGH will be made of the same type
2967 as the returned expression. If EXP is not a comparison, we will most
2968 likely not be returning a useful value and range. */
2971 make_range (tree exp
, int *pin_p
, tree
*plow
, tree
*phigh
)
2973 enum tree_code code
;
2974 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
2975 tree orig_type
= NULL_TREE
;
2977 tree low
, high
, n_low
, n_high
;
2979 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2980 and see if we can refine the range. Some of the cases below may not
2981 happen, but it doesn't seem worth worrying about this. We "continue"
2982 the outer loop when we've changed something; otherwise we "break"
2983 the switch, which will "break" the while. */
2985 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
2989 code
= TREE_CODE (exp
);
2991 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
2993 if (first_rtl_op (code
) > 0)
2994 arg0
= TREE_OPERAND (exp
, 0);
2995 if (TREE_CODE_CLASS (code
) == '<'
2996 || TREE_CODE_CLASS (code
) == '1'
2997 || TREE_CODE_CLASS (code
) == '2')
2998 type
= TREE_TYPE (arg0
);
2999 if (TREE_CODE_CLASS (code
) == '2'
3000 || TREE_CODE_CLASS (code
) == '<'
3001 || (TREE_CODE_CLASS (code
) == 'e'
3002 && TREE_CODE_LENGTH (code
) > 1))
3003 arg1
= TREE_OPERAND (exp
, 1);
3006 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
3007 lose a cast by accident. */
3008 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
3013 case TRUTH_NOT_EXPR
:
3014 in_p
= ! in_p
, exp
= arg0
;
3017 case EQ_EXPR
: case NE_EXPR
:
3018 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
3019 /* We can only do something if the range is testing for zero
3020 and if the second operand is an integer constant. Note that
3021 saying something is "in" the range we make is done by
3022 complementing IN_P since it will set in the initial case of
3023 being not equal to zero; "out" is leaving it alone. */
3024 if (low
== 0 || high
== 0
3025 || ! integer_zerop (low
) || ! integer_zerop (high
)
3026 || TREE_CODE (arg1
) != INTEGER_CST
)
3031 case NE_EXPR
: /* - [c, c] */
3034 case EQ_EXPR
: /* + [c, c] */
3035 in_p
= ! in_p
, low
= high
= arg1
;
3037 case GT_EXPR
: /* - [-, c] */
3038 low
= 0, high
= arg1
;
3040 case GE_EXPR
: /* + [c, -] */
3041 in_p
= ! in_p
, low
= arg1
, high
= 0;
3043 case LT_EXPR
: /* - [c, -] */
3044 low
= arg1
, high
= 0;
3046 case LE_EXPR
: /* + [-, c] */
3047 in_p
= ! in_p
, low
= 0, high
= arg1
;
3055 /* If this is an unsigned comparison, we also know that EXP is
3056 greater than or equal to zero. We base the range tests we make
3057 on that fact, so we record it here so we can parse existing
3059 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3061 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3062 1, convert (type
, integer_zero_node
),
3066 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3068 /* If the high bound is missing, but we
3069 have a low bound, reverse the range so
3070 it goes from zero to the low bound minus 1. */
3071 if (high
== 0 && low
)
3074 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3075 integer_one_node
, 0);
3076 low
= convert (type
, integer_zero_node
);
3082 /* (-x) IN [a,b] -> x in [-b, -a] */
3083 n_low
= range_binop (MINUS_EXPR
, type
,
3084 convert (type
, integer_zero_node
), 0, high
, 1);
3085 n_high
= range_binop (MINUS_EXPR
, type
,
3086 convert (type
, integer_zero_node
), 0, low
, 0);
3087 low
= n_low
, high
= n_high
;
3093 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3094 convert (type
, integer_one_node
));
3097 case PLUS_EXPR
: case MINUS_EXPR
:
3098 if (TREE_CODE (arg1
) != INTEGER_CST
)
3101 /* If EXP is signed, any overflow in the computation is undefined,
3102 so we don't worry about it so long as our computations on
3103 the bounds don't overflow. For unsigned, overflow is defined
3104 and this is exactly the right thing. */
3105 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3106 type
, low
, 0, arg1
, 0);
3107 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3108 type
, high
, 1, arg1
, 0);
3109 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3110 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3113 /* Check for an unsigned range which has wrapped around the maximum
3114 value thus making n_high < n_low, and normalize it. */
3115 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3117 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3118 integer_one_node
, 0);
3119 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3120 integer_one_node
, 0);
3122 /* If the range is of the form +/- [ x+1, x ], we won't
3123 be able to normalize it. But then, it represents the
3124 whole range or the empty set, so make it
3126 if (tree_int_cst_equal (n_low
, low
)
3127 && tree_int_cst_equal (n_high
, high
))
3133 low
= n_low
, high
= n_high
;
3138 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3139 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3142 if (! INTEGRAL_TYPE_P (type
)
3143 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3144 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3147 n_low
= low
, n_high
= high
;
3150 n_low
= convert (type
, n_low
);
3153 n_high
= convert (type
, n_high
);
3155 /* If we're converting from an unsigned to a signed type,
3156 we will be doing the comparison as unsigned. The tests above
3157 have already verified that LOW and HIGH are both positive.
3159 So we have to make sure that the original unsigned value will
3160 be interpreted as positive. */
3161 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3163 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3164 (TYPE_MODE (type
), 1);
3167 /* A range without an upper bound is, naturally, unbounded.
3168 Since convert would have cropped a very large value, use
3169 the max value for the destination type. */
3171 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3172 : TYPE_MAX_VALUE (type
);
3174 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3175 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3176 convert (type
, high_positive
),
3177 convert (type
, integer_one_node
)));
3179 /* If the low bound is specified, "and" the range with the
3180 range for which the original unsigned value will be
3184 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3186 1, convert (type
, integer_zero_node
),
3190 in_p
= (n_in_p
== in_p
);
3194 /* Otherwise, "or" the range with the range of the input
3195 that will be interpreted as negative. */
3196 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3198 1, convert (type
, integer_zero_node
),
3202 in_p
= (in_p
!= n_in_p
);
3207 low
= n_low
, high
= n_high
;
3217 /* If EXP is a constant, we can evaluate whether this is true or false. */
3218 if (TREE_CODE (exp
) == INTEGER_CST
)
3220 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3222 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3228 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3232 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3233 type, TYPE, return an expression to test if EXP is in (or out of, depending
3234 on IN_P) the range. */
3237 build_range_check (tree type
, tree exp
, int in_p
, tree low
, tree high
)
3239 tree etype
= TREE_TYPE (exp
);
3243 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3244 return invert_truthvalue (value
);
3246 if (low
== 0 && high
== 0)
3247 return convert (type
, integer_one_node
);
3250 return fold (build (LE_EXPR
, type
, exp
, high
));
3253 return fold (build (GE_EXPR
, type
, exp
, low
));
3255 if (operand_equal_p (low
, high
, 0))
3256 return fold (build (EQ_EXPR
, type
, exp
, low
));
3258 if (integer_zerop (low
))
3260 if (! TREE_UNSIGNED (etype
))
3262 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3263 high
= convert (etype
, high
);
3264 exp
= convert (etype
, exp
);
3266 return build_range_check (type
, exp
, 1, 0, high
);
3269 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3270 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3272 unsigned HOST_WIDE_INT lo
;
3276 prec
= TYPE_PRECISION (etype
);
3277 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3280 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3284 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3285 lo
= (unsigned HOST_WIDE_INT
) -1;
3288 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3290 if (TREE_UNSIGNED (etype
))
3292 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3293 exp
= convert (etype
, exp
);
3295 return fold (build (GT_EXPR
, type
, exp
,
3296 convert (etype
, integer_zero_node
)));
3300 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3301 && ! TREE_OVERFLOW (value
))
3302 return build_range_check (type
,
3303 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3304 1, convert (etype
, integer_zero_node
), value
);
3309 /* Given two ranges, see if we can merge them into one. Return 1 if we
3310 can, 0 if we can't. Set the output range into the specified parameters. */
3313 merge_ranges (int *pin_p
, tree
*plow
, tree
*phigh
, int in0_p
, tree low0
,
3314 tree high0
, int in1_p
, tree low1
, tree high1
)
3322 int lowequal
= ((low0
== 0 && low1
== 0)
3323 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3324 low0
, 0, low1
, 0)));
3325 int highequal
= ((high0
== 0 && high1
== 0)
3326 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3327 high0
, 1, high1
, 1)));
3329 /* Make range 0 be the range that starts first, or ends last if they
3330 start at the same value. Swap them if it isn't. */
3331 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3334 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3335 high1
, 1, high0
, 1))))
3337 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3338 tem
= low0
, low0
= low1
, low1
= tem
;
3339 tem
= high0
, high0
= high1
, high1
= tem
;
3342 /* Now flag two cases, whether the ranges are disjoint or whether the
3343 second range is totally subsumed in the first. Note that the tests
3344 below are simplified by the ones above. */
3345 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3346 high0
, 1, low1
, 0));
3347 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3348 high1
, 1, high0
, 1));
3350 /* We now have four cases, depending on whether we are including or
3351 excluding the two ranges. */
3354 /* If they don't overlap, the result is false. If the second range
3355 is a subset it is the result. Otherwise, the range is from the start
3356 of the second to the end of the first. */
3358 in_p
= 0, low
= high
= 0;
3360 in_p
= 1, low
= low1
, high
= high1
;
3362 in_p
= 1, low
= low1
, high
= high0
;
3365 else if (in0_p
&& ! in1_p
)
3367 /* If they don't overlap, the result is the first range. If they are
3368 equal, the result is false. If the second range is a subset of the
3369 first, and the ranges begin at the same place, we go from just after
3370 the end of the first range to the end of the second. If the second
3371 range is not a subset of the first, or if it is a subset and both
3372 ranges end at the same place, the range starts at the start of the
3373 first range and ends just before the second range.
3374 Otherwise, we can't describe this as a single range. */
3376 in_p
= 1, low
= low0
, high
= high0
;
3377 else if (lowequal
&& highequal
)
3378 in_p
= 0, low
= high
= 0;
3379 else if (subset
&& lowequal
)
3381 in_p
= 1, high
= high0
;
3382 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3383 integer_one_node
, 0);
3385 else if (! subset
|| highequal
)
3387 in_p
= 1, low
= low0
;
3388 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3389 integer_one_node
, 0);
3395 else if (! in0_p
&& in1_p
)
3397 /* If they don't overlap, the result is the second range. If the second
3398 is a subset of the first, the result is false. Otherwise,
3399 the range starts just after the first range and ends at the
3400 end of the second. */
3402 in_p
= 1, low
= low1
, high
= high1
;
3403 else if (subset
|| highequal
)
3404 in_p
= 0, low
= high
= 0;
3407 in_p
= 1, high
= high1
;
3408 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3409 integer_one_node
, 0);
3415 /* The case where we are excluding both ranges. Here the complex case
3416 is if they don't overlap. In that case, the only time we have a
3417 range is if they are adjacent. If the second is a subset of the
3418 first, the result is the first. Otherwise, the range to exclude
3419 starts at the beginning of the first range and ends at the end of the
3423 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3424 range_binop (PLUS_EXPR
, NULL_TREE
,
3426 integer_one_node
, 1),
3428 in_p
= 0, low
= low0
, high
= high1
;
3433 in_p
= 0, low
= low0
, high
= high0
;
3435 in_p
= 0, low
= low0
, high
= high1
;
3438 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3442 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3443 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3446 /* EXP is some logical combination of boolean tests. See if we can
3447 merge it into some range test. Return the new tree if so. */
3450 fold_range_test (tree exp
)
3452 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3453 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3454 int in0_p
, in1_p
, in_p
;
3455 tree low0
, low1
, low
, high0
, high1
, high
;
3456 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3457 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3460 /* If this is an OR operation, invert both sides; we will invert
3461 again at the end. */
3463 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3465 /* If both expressions are the same, if we can merge the ranges, and we
3466 can build the range test, return it or it inverted. If one of the
3467 ranges is always true or always false, consider it to be the same
3468 expression as the other. */
3469 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3470 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3472 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3474 : rhs
!= 0 ? rhs
: integer_zero_node
,
3476 return or_op
? invert_truthvalue (tem
) : tem
;
3478 /* On machines where the branch cost is expensive, if this is a
3479 short-circuited branch and the underlying object on both sides
3480 is the same, make a non-short-circuit operation. */
3481 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3482 && lhs
!= 0 && rhs
!= 0
3483 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3484 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3485 && operand_equal_p (lhs
, rhs
, 0))
3487 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3488 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3489 which cases we can't do this. */
3490 if (simple_operand_p (lhs
))
3491 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3492 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3493 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3494 TREE_OPERAND (exp
, 1));
3496 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3497 && ! CONTAINS_PLACEHOLDER_P (lhs
))
3499 tree common
= save_expr (lhs
);
3501 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3502 or_op
? ! in0_p
: in0_p
,
3504 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3505 or_op
? ! in1_p
: in1_p
,
3507 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3508 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3509 TREE_TYPE (exp
), lhs
, rhs
);
3516 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3517 bit value. Arrange things so the extra bits will be set to zero if and
3518 only if C is signed-extended to its full width. If MASK is nonzero,
3519 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3522 unextend (tree c
, int p
, int unsignedp
, tree mask
)
3524 tree type
= TREE_TYPE (c
);
3525 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3528 if (p
== modesize
|| unsignedp
)
3531 /* We work by getting just the sign bit into the low-order bit, then
3532 into the high-order bit, then sign-extend. We then XOR that value
3534 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3535 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3537 /* We must use a signed type in order to get an arithmetic right shift.
3538 However, we must also avoid introducing accidental overflows, so that
3539 a subsequent call to integer_zerop will work. Hence we must
3540 do the type conversion here. At this point, the constant is either
3541 zero or one, and the conversion to a signed type can never overflow.
3542 We could get an overflow if this conversion is done anywhere else. */
3543 if (TREE_UNSIGNED (type
))
3544 temp
= convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3546 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3547 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3549 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3550 /* If necessary, convert the type back to match the type of C. */
3551 if (TREE_UNSIGNED (type
))
3552 temp
= convert (type
, temp
);
3554 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3557 /* Find ways of folding logical expressions of LHS and RHS:
3558 Try to merge two comparisons to the same innermost item.
3559 Look for range tests like "ch >= '0' && ch <= '9'".
3560 Look for combinations of simple terms on machines with expensive branches
3561 and evaluate the RHS unconditionally.
3563 For example, if we have p->a == 2 && p->b == 4 and we can make an
3564 object large enough to span both A and B, we can do this with a comparison
3565 against the object ANDed with the a mask.
3567 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3568 operations to do this with one comparison.
3570 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3571 function and the one above.
3573 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3574 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3576 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3579 We return the simplified tree or 0 if no optimization is possible. */
3582 fold_truthop (enum tree_code code
, tree truth_type
, tree lhs
, tree rhs
)
3584 /* If this is the "or" of two comparisons, we can do something if
3585 the comparisons are NE_EXPR. If this is the "and", we can do something
3586 if the comparisons are EQ_EXPR. I.e.,
3587 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3589 WANTED_CODE is this operation code. For single bit fields, we can
3590 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3591 comparison for one-bit fields. */
3593 enum tree_code wanted_code
;
3594 enum tree_code lcode
, rcode
;
3595 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3596 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3597 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3598 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3599 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3600 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3601 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3602 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3603 enum machine_mode lnmode
, rnmode
;
3604 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3605 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3606 tree l_const
, r_const
;
3607 tree lntype
, rntype
, result
;
3608 int first_bit
, end_bit
;
3611 /* Start by getting the comparison codes. Fail if anything is volatile.
3612 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3613 it were surrounded with a NE_EXPR. */
3615 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3618 lcode
= TREE_CODE (lhs
);
3619 rcode
= TREE_CODE (rhs
);
3621 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3622 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3624 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3625 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3627 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3630 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3631 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3633 ll_arg
= TREE_OPERAND (lhs
, 0);
3634 lr_arg
= TREE_OPERAND (lhs
, 1);
3635 rl_arg
= TREE_OPERAND (rhs
, 0);
3636 rr_arg
= TREE_OPERAND (rhs
, 1);
3638 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3639 if (simple_operand_p (ll_arg
)
3640 && simple_operand_p (lr_arg
)
3641 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3645 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3646 && operand_equal_p (lr_arg
, rr_arg
, 0))
3648 int lcompcode
, rcompcode
;
3650 lcompcode
= comparison_to_compcode (lcode
);
3651 rcompcode
= comparison_to_compcode (rcode
);
3652 compcode
= (code
== TRUTH_AND_EXPR
)
3653 ? lcompcode
& rcompcode
3654 : lcompcode
| rcompcode
;
3656 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3657 && operand_equal_p (lr_arg
, rl_arg
, 0))
3659 int lcompcode
, rcompcode
;
3661 rcode
= swap_tree_comparison (rcode
);
3662 lcompcode
= comparison_to_compcode (lcode
);
3663 rcompcode
= comparison_to_compcode (rcode
);
3664 compcode
= (code
== TRUTH_AND_EXPR
)
3665 ? lcompcode
& rcompcode
3666 : lcompcode
| rcompcode
;
3671 if (compcode
== COMPCODE_TRUE
)
3672 return convert (truth_type
, integer_one_node
);
3673 else if (compcode
== COMPCODE_FALSE
)
3674 return convert (truth_type
, integer_zero_node
);
3675 else if (compcode
!= -1)
3676 return build (compcode_to_comparison (compcode
),
3677 truth_type
, ll_arg
, lr_arg
);
3680 /* If the RHS can be evaluated unconditionally and its operands are
3681 simple, it wins to evaluate the RHS unconditionally on machines
3682 with expensive branches. In this case, this isn't a comparison
3683 that can be merged. Avoid doing this if the RHS is a floating-point
3684 comparison since those can trap. */
3686 if (BRANCH_COST
>= 2
3687 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3688 && simple_operand_p (rl_arg
)
3689 && simple_operand_p (rr_arg
))
3691 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3692 if (code
== TRUTH_OR_EXPR
3693 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
3694 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
3695 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3696 return build (NE_EXPR
, truth_type
,
3697 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3701 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3702 if (code
== TRUTH_AND_EXPR
3703 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
3704 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
3705 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3706 return build (EQ_EXPR
, truth_type
,
3707 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3711 return build (code
, truth_type
, lhs
, rhs
);
3714 /* See if the comparisons can be merged. Then get all the parameters for
3717 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3718 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3722 ll_inner
= decode_field_reference (ll_arg
,
3723 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3724 &ll_unsignedp
, &volatilep
, &ll_mask
,
3726 lr_inner
= decode_field_reference (lr_arg
,
3727 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3728 &lr_unsignedp
, &volatilep
, &lr_mask
,
3730 rl_inner
= decode_field_reference (rl_arg
,
3731 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3732 &rl_unsignedp
, &volatilep
, &rl_mask
,
3734 rr_inner
= decode_field_reference (rr_arg
,
3735 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3736 &rr_unsignedp
, &volatilep
, &rr_mask
,
3739 /* It must be true that the inner operation on the lhs of each
3740 comparison must be the same if we are to be able to do anything.
3741 Then see if we have constants. If not, the same must be true for
3743 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3744 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3747 if (TREE_CODE (lr_arg
) == INTEGER_CST
3748 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3749 l_const
= lr_arg
, r_const
= rr_arg
;
3750 else if (lr_inner
== 0 || rr_inner
== 0
3751 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3754 l_const
= r_const
= 0;
3756 /* If either comparison code is not correct for our logical operation,
3757 fail. However, we can convert a one-bit comparison against zero into
3758 the opposite comparison against that bit being set in the field. */
3760 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3761 if (lcode
!= wanted_code
)
3763 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3765 /* Make the left operand unsigned, since we are only interested
3766 in the value of one bit. Otherwise we are doing the wrong
3775 /* This is analogous to the code for l_const above. */
3776 if (rcode
!= wanted_code
)
3778 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3787 /* After this point all optimizations will generate bit-field
3788 references, which we might not want. */
3789 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
3792 /* See if we can find a mode that contains both fields being compared on
3793 the left. If we can't, fail. Otherwise, update all constants and masks
3794 to be relative to a field of that size. */
3795 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3796 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3797 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3798 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3800 if (lnmode
== VOIDmode
)
3803 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3804 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3805 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
3806 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3808 if (BYTES_BIG_ENDIAN
)
3810 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3811 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3814 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3815 size_int (xll_bitpos
), 0);
3816 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3817 size_int (xrl_bitpos
), 0);
3821 l_const
= convert (lntype
, l_const
);
3822 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3823 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3824 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3825 fold (build1 (BIT_NOT_EXPR
,
3829 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3831 return convert (truth_type
,
3832 wanted_code
== NE_EXPR
3833 ? integer_one_node
: integer_zero_node
);
3838 r_const
= convert (lntype
, r_const
);
3839 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3840 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3841 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3842 fold (build1 (BIT_NOT_EXPR
,
3846 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3848 return convert (truth_type
,
3849 wanted_code
== NE_EXPR
3850 ? integer_one_node
: integer_zero_node
);
3854 /* If the right sides are not constant, do the same for it. Also,
3855 disallow this optimization if a size or signedness mismatch occurs
3856 between the left and right sides. */
3859 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
3860 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
3861 /* Make sure the two fields on the right
3862 correspond to the left without being swapped. */
3863 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
3866 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
3867 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
3868 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3869 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
3871 if (rnmode
== VOIDmode
)
3874 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
3875 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
3876 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
3877 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
3879 if (BYTES_BIG_ENDIAN
)
3881 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
3882 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
3885 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
3886 size_int (xlr_bitpos
), 0);
3887 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
3888 size_int (xrr_bitpos
), 0);
3890 /* Make a mask that corresponds to both fields being compared.
3891 Do this for both items being compared. If the operands are the
3892 same size and the bits being compared are in the same position
3893 then we can do this by masking both and comparing the masked
3895 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3896 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
3897 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
3899 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3900 ll_unsignedp
|| rl_unsignedp
);
3901 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3902 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
3904 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
3905 lr_unsignedp
|| rr_unsignedp
);
3906 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
3907 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
3909 return build (wanted_code
, truth_type
, lhs
, rhs
);
3912 /* There is still another way we can do something: If both pairs of
3913 fields being compared are adjacent, we may be able to make a wider
3914 field containing them both.
3916 Note that we still must mask the lhs/rhs expressions. Furthermore,
3917 the mask must be shifted to account for the shift done by
3918 make_bit_field_ref. */
3919 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
3920 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
3921 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
3922 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
3926 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
3927 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
3928 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
3929 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
3931 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
3932 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
3933 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
3934 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
3936 /* Convert to the smaller type before masking out unwanted bits. */
3938 if (lntype
!= rntype
)
3940 if (lnbitsize
> rnbitsize
)
3942 lhs
= convert (rntype
, lhs
);
3943 ll_mask
= convert (rntype
, ll_mask
);
3946 else if (lnbitsize
< rnbitsize
)
3948 rhs
= convert (lntype
, rhs
);
3949 lr_mask
= convert (lntype
, lr_mask
);
3954 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
3955 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
3957 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
3958 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
3960 return build (wanted_code
, truth_type
, lhs
, rhs
);
3966 /* Handle the case of comparisons with constants. If there is something in
3967 common between the masks, those bits of the constants must be the same.
3968 If not, the condition is always false. Test for this to avoid generating
3969 incorrect code below. */
3970 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
3971 if (! integer_zerop (result
)
3972 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
3973 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
3975 if (wanted_code
== NE_EXPR
)
3977 warning ("`or' of unmatched not-equal tests is always 1");
3978 return convert (truth_type
, integer_one_node
);
3982 warning ("`and' of mutually exclusive equal-tests is always 0");
3983 return convert (truth_type
, integer_zero_node
);
3987 /* Construct the expression we will return. First get the component
3988 reference we will make. Unless the mask is all ones the width of
3989 that field, perform the mask operation. Then compare with the
3991 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3992 ll_unsignedp
|| rl_unsignedp
);
3994 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3995 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3996 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
3998 return build (wanted_code
, truth_type
, result
,
3999 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
4002 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
4006 optimize_minmax_comparison (tree t
)
4008 tree type
= TREE_TYPE (t
);
4009 tree arg0
= TREE_OPERAND (t
, 0);
4010 enum tree_code op_code
;
4011 tree comp_const
= TREE_OPERAND (t
, 1);
4013 int consts_equal
, consts_lt
;
4016 STRIP_SIGN_NOPS (arg0
);
4018 op_code
= TREE_CODE (arg0
);
4019 minmax_const
= TREE_OPERAND (arg0
, 1);
4020 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4021 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4022 inner
= TREE_OPERAND (arg0
, 0);
4024 /* If something does not permit us to optimize, return the original tree. */
4025 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4026 || TREE_CODE (comp_const
) != INTEGER_CST
4027 || TREE_CONSTANT_OVERFLOW (comp_const
)
4028 || TREE_CODE (minmax_const
) != INTEGER_CST
4029 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4032 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4033 and GT_EXPR, doing the rest with recursive calls using logical
4035 switch (TREE_CODE (t
))
4037 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4039 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4043 fold (build (TRUTH_ORIF_EXPR
, type
,
4044 optimize_minmax_comparison
4045 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4046 optimize_minmax_comparison
4047 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4050 if (op_code
== MAX_EXPR
&& consts_equal
)
4051 /* MAX (X, 0) == 0 -> X <= 0 */
4052 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4054 else if (op_code
== MAX_EXPR
&& consts_lt
)
4055 /* MAX (X, 0) == 5 -> X == 5 */
4056 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4058 else if (op_code
== MAX_EXPR
)
4059 /* MAX (X, 0) == -1 -> false */
4060 return omit_one_operand (type
, integer_zero_node
, inner
);
4062 else if (consts_equal
)
4063 /* MIN (X, 0) == 0 -> X >= 0 */
4064 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4067 /* MIN (X, 0) == 5 -> false */
4068 return omit_one_operand (type
, integer_zero_node
, inner
);
4071 /* MIN (X, 0) == -1 -> X == -1 */
4072 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4075 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4076 /* MAX (X, 0) > 0 -> X > 0
4077 MAX (X, 0) > 5 -> X > 5 */
4078 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4080 else if (op_code
== MAX_EXPR
)
4081 /* MAX (X, 0) > -1 -> true */
4082 return omit_one_operand (type
, integer_one_node
, inner
);
4084 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4085 /* MIN (X, 0) > 0 -> false
4086 MIN (X, 0) > 5 -> false */
4087 return omit_one_operand (type
, integer_zero_node
, inner
);
4090 /* MIN (X, 0) > -1 -> X > -1 */
4091 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4098 /* T is an integer expression that is being multiplied, divided, or taken a
4099 modulus (CODE says which and what kind of divide or modulus) by a
4100 constant C. See if we can eliminate that operation by folding it with
4101 other operations already in T. WIDE_TYPE, if non-null, is a type that
4102 should be used for the computation if wider than our type.
4104 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4105 (X * 2) + (Y * 4). We must, however, be assured that either the original
4106 expression would not overflow or that overflow is undefined for the type
4107 in the language in question.
4109 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4110 the machine has a multiply-accumulate insn or that this is part of an
4111 addressing calculation.
4113 If we return a non-null expression, it is an equivalent form of the
4114 original computation, but need not be in the original type. */
4117 extract_muldiv (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4119 /* To avoid exponential search depth, refuse to allow recursion past
4120 three levels. Beyond that (1) it's highly unlikely that we'll find
4121 something interesting and (2) we've probably processed it before
4122 when we built the inner expression. */
4131 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4138 extract_muldiv_1 (tree t
, tree c
, enum tree_code code
, tree wide_type
)
4140 tree type
= TREE_TYPE (t
);
4141 enum tree_code tcode
= TREE_CODE (t
);
4142 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4143 > GET_MODE_SIZE (TYPE_MODE (type
)))
4144 ? wide_type
: type
);
4146 int same_p
= tcode
== code
;
4147 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4149 /* Don't deal with constants of zero here; they confuse the code below. */
4150 if (integer_zerop (c
))
4153 if (TREE_CODE_CLASS (tcode
) == '1')
4154 op0
= TREE_OPERAND (t
, 0);
4156 if (TREE_CODE_CLASS (tcode
) == '2')
4157 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4159 /* Note that we need not handle conditional operations here since fold
4160 already handles those cases. So just do arithmetic here. */
4164 /* For a constant, we can always simplify if we are a multiply
4165 or (for divide and modulus) if it is a multiple of our constant. */
4166 if (code
== MULT_EXPR
4167 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4168 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4171 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4172 /* If op0 is an expression ... */
4173 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4174 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4175 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4176 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4177 /* ... and is unsigned, and its type is smaller than ctype,
4178 then we cannot pass through as widening. */
4179 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4180 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4181 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4182 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4183 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4184 /* ... or its type is larger than ctype,
4185 then we cannot pass through this truncation. */
4186 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4187 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
4188 /* ... or signedness changes for division or modulus,
4189 then we cannot pass through this conversion. */
4190 || (code
!= MULT_EXPR
4191 && (TREE_UNSIGNED (ctype
)
4192 != TREE_UNSIGNED (TREE_TYPE (op0
))))))
4195 /* Pass the constant down and see if we can make a simplification. If
4196 we can, replace this expression with the inner simplification for
4197 possible later conversion to our or some other type. */
4198 if ((t2
= convert (TREE_TYPE (op0
), c
)) != 0
4199 && TREE_CODE (t2
) == INTEGER_CST
4200 && ! TREE_CONSTANT_OVERFLOW (t2
)
4201 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
4203 ? ctype
: NULL_TREE
))))
4207 case NEGATE_EXPR
: case ABS_EXPR
:
4208 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4209 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4212 case MIN_EXPR
: case MAX_EXPR
:
4213 /* If widening the type changes the signedness, then we can't perform
4214 this optimization as that changes the result. */
4215 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4218 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4219 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4220 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4222 if (tree_int_cst_sgn (c
) < 0)
4223 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4225 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4226 convert (ctype
, t2
)));
4230 case WITH_RECORD_EXPR
:
4231 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4232 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4233 TREE_OPERAND (t
, 1));
4236 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4237 /* If the second operand is constant, this is a multiplication
4238 or floor division, by a power of two, so we can treat it that
4239 way unless the multiplier or divisor overflows. */
4240 if (TREE_CODE (op1
) == INTEGER_CST
4241 /* const_binop may not detect overflow correctly,
4242 so check for it explicitly here. */
4243 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4244 && TREE_INT_CST_HIGH (op1
) == 0
4245 && 0 != (t1
= convert (ctype
,
4246 const_binop (LSHIFT_EXPR
, size_one_node
,
4248 && ! TREE_OVERFLOW (t1
))
4249 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4250 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4251 ctype
, convert (ctype
, op0
), t1
),
4252 c
, code
, wide_type
);
4255 case PLUS_EXPR
: case MINUS_EXPR
:
4256 /* See if we can eliminate the operation on both sides. If we can, we
4257 can return a new PLUS or MINUS. If we can't, the only remaining
4258 cases where we can do anything are if the second operand is a
4260 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4261 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4262 if (t1
!= 0 && t2
!= 0
4263 && (code
== MULT_EXPR
4264 /* If not multiplication, we can only do this if both operands
4265 are divisible by c. */
4266 || (multiple_of_p (ctype
, op0
, c
)
4267 && multiple_of_p (ctype
, op1
, c
))))
4268 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4269 convert (ctype
, t2
)));
4271 /* If this was a subtraction, negate OP1 and set it to be an addition.
4272 This simplifies the logic below. */
4273 if (tcode
== MINUS_EXPR
)
4274 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4276 if (TREE_CODE (op1
) != INTEGER_CST
)
4279 /* If either OP1 or C are negative, this optimization is not safe for
4280 some of the division and remainder types while for others we need
4281 to change the code. */
4282 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4284 if (code
== CEIL_DIV_EXPR
)
4285 code
= FLOOR_DIV_EXPR
;
4286 else if (code
== FLOOR_DIV_EXPR
)
4287 code
= CEIL_DIV_EXPR
;
4288 else if (code
!= MULT_EXPR
4289 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4293 /* If it's a multiply or a division/modulus operation of a multiple
4294 of our constant, do the operation and verify it doesn't overflow. */
4295 if (code
== MULT_EXPR
4296 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4298 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4299 if (op1
== 0 || TREE_OVERFLOW (op1
))
4305 /* If we have an unsigned type is not a sizetype, we cannot widen
4306 the operation since it will change the result if the original
4307 computation overflowed. */
4308 if (TREE_UNSIGNED (ctype
)
4309 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4313 /* If we were able to eliminate our operation from the first side,
4314 apply our operation to the second side and reform the PLUS. */
4315 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4316 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4318 /* The last case is if we are a multiply. In that case, we can
4319 apply the distributive law to commute the multiply and addition
4320 if the multiplication of the constants doesn't overflow. */
4321 if (code
== MULT_EXPR
)
4322 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4323 convert (ctype
, op0
),
4324 convert (ctype
, c
))),
4330 /* We have a special case here if we are doing something like
4331 (C * 8) % 4 since we know that's zero. */
4332 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4333 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4334 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4335 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4336 return omit_one_operand (type
, integer_zero_node
, op0
);
4338 /* ... fall through ... */
4340 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4341 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4342 /* If we can extract our operation from the LHS, do so and return a
4343 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4344 do something only if the second operand is a constant. */
4346 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4347 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4348 convert (ctype
, op1
)));
4349 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4350 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4351 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4352 convert (ctype
, t1
)));
4353 else if (TREE_CODE (op1
) != INTEGER_CST
)
4356 /* If these are the same operation types, we can associate them
4357 assuming no overflow. */
4359 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4360 convert (ctype
, c
), 0))
4361 && ! TREE_OVERFLOW (t1
))
4362 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4364 /* If these operations "cancel" each other, we have the main
4365 optimizations of this pass, which occur when either constant is a
4366 multiple of the other, in which case we replace this with either an
4367 operation or CODE or TCODE.
4369 If we have an unsigned type that is not a sizetype, we cannot do
4370 this since it will change the result if the original computation
4372 if ((! TREE_UNSIGNED (ctype
)
4373 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4375 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4376 || (tcode
== MULT_EXPR
4377 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4378 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4380 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4381 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4383 const_binop (TRUNC_DIV_EXPR
,
4385 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4386 return fold (build (code
, ctype
, convert (ctype
, op0
),
4388 const_binop (TRUNC_DIV_EXPR
,
4400 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4401 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4402 that we may sometimes modify the tree. */
4405 strip_compound_expr (tree t
, tree s
)
4407 enum tree_code code
= TREE_CODE (t
);
4409 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4410 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4411 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4412 return TREE_OPERAND (t
, 1);
4414 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4415 don't bother handling any other types. */
4416 else if (code
== COND_EXPR
)
4418 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4419 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4420 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4422 else if (TREE_CODE_CLASS (code
) == '1')
4423 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4424 else if (TREE_CODE_CLASS (code
) == '<'
4425 || TREE_CODE_CLASS (code
) == '2')
4427 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4428 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4434 /* Return a node which has the indicated constant VALUE (either 0 or
4435 1), and is of the indicated TYPE. */
4438 constant_boolean_node (int value
, tree type
)
4440 if (type
== integer_type_node
)
4441 return value
? integer_one_node
: integer_zero_node
;
4442 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4443 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4447 tree t
= build_int_2 (value
, 0);
4449 TREE_TYPE (t
) = type
;
4454 /* Utility function for the following routine, to see how complex a nesting of
4455 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4456 we don't care (to avoid spending too much time on complex expressions.). */
4459 count_cond (tree expr
, int lim
)
4463 if (TREE_CODE (expr
) != COND_EXPR
)
4468 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4469 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4470 return MIN (lim
, 1 + ctrue
+ cfalse
);
4473 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4474 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4475 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4476 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4477 COND is the first argument to CODE; otherwise (as in the example
4478 given here), it is the second argument. TYPE is the type of the
4479 original expression. */
4482 fold_binary_op_with_conditional_arg (enum tree_code code
, tree type
,
4483 tree cond
, tree arg
, int cond_first_p
)
4485 tree test
, true_value
, false_value
;
4486 tree lhs
= NULL_TREE
;
4487 tree rhs
= NULL_TREE
;
4488 /* In the end, we'll produce a COND_EXPR. Both arms of the
4489 conditional expression will be binary operations. The left-hand
4490 side of the expression to be executed if the condition is true
4491 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4492 of the expression to be executed if the condition is true will be
4493 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4494 but apply to the expression to be executed if the conditional is
4500 /* These are the codes to use for the left-hand side and right-hand
4501 side of the COND_EXPR. Normally, they are the same as CODE. */
4502 enum tree_code lhs_code
= code
;
4503 enum tree_code rhs_code
= code
;
4504 /* And these are the types of the expressions. */
4505 tree lhs_type
= type
;
4506 tree rhs_type
= type
;
4511 true_rhs
= false_rhs
= &arg
;
4512 true_lhs
= &true_value
;
4513 false_lhs
= &false_value
;
4517 true_lhs
= false_lhs
= &arg
;
4518 true_rhs
= &true_value
;
4519 false_rhs
= &false_value
;
4522 if (TREE_CODE (cond
) == COND_EXPR
)
4524 test
= TREE_OPERAND (cond
, 0);
4525 true_value
= TREE_OPERAND (cond
, 1);
4526 false_value
= TREE_OPERAND (cond
, 2);
4527 /* If this operand throws an expression, then it does not make
4528 sense to try to perform a logical or arithmetic operation
4529 involving it. Instead of building `a + throw 3' for example,
4530 we simply build `a, throw 3'. */
4531 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4535 lhs_code
= COMPOUND_EXPR
;
4536 lhs_type
= void_type_node
;
4541 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4545 rhs_code
= COMPOUND_EXPR
;
4546 rhs_type
= void_type_node
;
4554 tree testtype
= TREE_TYPE (cond
);
4556 true_value
= convert (testtype
, integer_one_node
);
4557 false_value
= convert (testtype
, integer_zero_node
);
4560 /* If ARG is complex we want to make sure we only evaluate it once. Though
4561 this is only required if it is volatile, it might be more efficient even
4562 if it is not. However, if we succeed in folding one part to a constant,
4563 we do not need to make this SAVE_EXPR. Since we do this optimization
4564 primarily to see if we do end up with constant and this SAVE_EXPR
4565 interferes with later optimizations, suppressing it when we can is
4568 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4569 do so. Don't try to see if the result is a constant if an arm is a
4570 COND_EXPR since we get exponential behavior in that case. */
4572 if (saved_expr_p (arg
))
4574 else if (lhs
== 0 && rhs
== 0
4575 && !TREE_CONSTANT (arg
)
4576 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4577 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4578 || TREE_SIDE_EFFECTS (arg
)))
4580 if (TREE_CODE (true_value
) != COND_EXPR
)
4581 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4583 if (TREE_CODE (false_value
) != COND_EXPR
)
4584 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4586 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4587 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4589 arg
= save_expr (arg
);
4596 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4598 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4600 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4603 return build (COMPOUND_EXPR
, type
,
4604 convert (void_type_node
, arg
),
4605 strip_compound_expr (test
, arg
));
4607 return convert (type
, test
);
4611 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4613 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4614 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4615 ADDEND is the same as X.
4617 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4618 and finite. The problematic cases are when X is zero, and its mode
4619 has signed zeros. In the case of rounding towards -infinity,
4620 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4621 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4624 fold_real_zero_addition_p (tree type
, tree addend
, int negate
)
4626 if (!real_zerop (addend
))
4629 /* Don't allow the fold with -fsignaling-nans. */
4630 if (HONOR_SNANS (TYPE_MODE (type
)))
4633 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4634 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4637 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4638 if (TREE_CODE (addend
) == REAL_CST
4639 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4642 /* The mode has signed zeros, and we have to honor their sign.
4643 In this situation, there is only one case we can return true for.
4644 X - 0 is the same as X unless rounding towards -infinity is
4646 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4649 /* Subroutine of fold() that checks comparisons of built-in math
4650 functions against real constants.
4652 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4653 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4654 is the type of the result and ARG0 and ARG1 are the operands of the
4655 comparison. ARG1 must be a TREE_REAL_CST.
4657 The function returns the constant folded tree if a simplification
4658 can be made, and NULL_TREE otherwise. */
4661 fold_mathfn_compare (enum built_in_function fcode
, enum tree_code code
,
4662 tree type
, tree arg0
, tree arg1
)
4666 if (fcode
== BUILT_IN_SQRT
4667 || fcode
== BUILT_IN_SQRTF
4668 || fcode
== BUILT_IN_SQRTL
)
4670 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
4671 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
4673 c
= TREE_REAL_CST (arg1
);
4674 if (REAL_VALUE_NEGATIVE (c
))
4676 /* sqrt(x) < y is always false, if y is negative. */
4677 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
4678 return omit_one_operand (type
,
4679 convert (type
, integer_zero_node
),
4682 /* sqrt(x) > y is always true, if y is negative and we
4683 don't care about NaNs, i.e. negative values of x. */
4684 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
4685 return omit_one_operand (type
,
4686 convert (type
, integer_one_node
),
4689 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4690 return fold (build (GE_EXPR
, type
, arg
,
4691 build_real (TREE_TYPE (arg
), dconst0
)));
4693 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
4697 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4698 real_convert (&c2
, mode
, &c2
);
4700 if (REAL_VALUE_ISINF (c2
))
4702 /* sqrt(x) > y is x == +Inf, when y is very large. */
4703 if (HONOR_INFINITIES (mode
))
4704 return fold (build (EQ_EXPR
, type
, arg
,
4705 build_real (TREE_TYPE (arg
), c2
)));
4707 /* sqrt(x) > y is always false, when y is very large
4708 and we don't care about infinities. */
4709 return omit_one_operand (type
,
4710 convert (type
, integer_zero_node
),
4714 /* sqrt(x) > c is the same as x > c*c. */
4715 return fold (build (code
, type
, arg
,
4716 build_real (TREE_TYPE (arg
), c2
)));
4718 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
4722 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4723 real_convert (&c2
, mode
, &c2
);
4725 if (REAL_VALUE_ISINF (c2
))
4727 /* sqrt(x) < y is always true, when y is a very large
4728 value and we don't care about NaNs or Infinities. */
4729 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
4730 return omit_one_operand (type
,
4731 convert (type
, integer_one_node
),
4734 /* sqrt(x) < y is x != +Inf when y is very large and we
4735 don't care about NaNs. */
4736 if (! HONOR_NANS (mode
))
4737 return fold (build (NE_EXPR
, type
, arg
,
4738 build_real (TREE_TYPE (arg
), c2
)));
4740 /* sqrt(x) < y is x >= 0 when y is very large and we
4741 don't care about Infinities. */
4742 if (! HONOR_INFINITIES (mode
))
4743 return fold (build (GE_EXPR
, type
, arg
,
4744 build_real (TREE_TYPE (arg
), dconst0
)));
4746 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4747 if ((*lang_hooks
.decls
.global_bindings_p
) () != 0
4748 || CONTAINS_PLACEHOLDER_P (arg
))
4751 arg
= save_expr (arg
);
4752 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4753 fold (build (GE_EXPR
, type
, arg
,
4754 build_real (TREE_TYPE (arg
),
4756 fold (build (NE_EXPR
, type
, arg
,
4757 build_real (TREE_TYPE (arg
),
4761 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4762 if (! HONOR_NANS (mode
))
4763 return fold (build (code
, type
, arg
,
4764 build_real (TREE_TYPE (arg
), c2
)));
4766 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4767 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4768 && ! CONTAINS_PLACEHOLDER_P (arg
))
4770 arg
= save_expr (arg
);
4771 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4772 fold (build (GE_EXPR
, type
, arg
,
4773 build_real (TREE_TYPE (arg
),
4775 fold (build (code
, type
, arg
,
4776 build_real (TREE_TYPE (arg
),
4785 /* Subroutine of fold() that optimizes comparisons against Infinities,
4786 either +Inf or -Inf.
4788 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4789 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4790 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4792 The function returns the constant folded tree if a simplification
4793 can be made, and NULL_TREE otherwise. */
4796 fold_inf_compare (enum tree_code code
, tree type
, tree arg0
, tree arg1
)
4798 enum machine_mode mode
;
4799 REAL_VALUE_TYPE max
;
4803 mode
= TYPE_MODE (TREE_TYPE (arg0
));
4805 /* For negative infinity swap the sense of the comparison. */
4806 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
4808 code
= swap_tree_comparison (code
);
4813 /* x > +Inf is always false, if with ignore sNANs. */
4814 if (HONOR_SNANS (mode
))
4816 return omit_one_operand (type
,
4817 convert (type
, integer_zero_node
),
4821 /* x <= +Inf is always true, if we don't case about NaNs. */
4822 if (! HONOR_NANS (mode
))
4823 return omit_one_operand (type
,
4824 convert (type
, integer_one_node
),
4827 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4828 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4829 && ! CONTAINS_PLACEHOLDER_P (arg0
))
4831 arg0
= save_expr (arg0
);
4832 return fold (build (EQ_EXPR
, type
, arg0
, arg0
));
4838 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4839 real_maxval (&max
, neg
, mode
);
4840 return fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4841 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4844 /* x < +Inf is always equal to x <= DBL_MAX. */
4845 real_maxval (&max
, neg
, mode
);
4846 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4847 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4850 /* x != +Inf is always equal to !(x > DBL_MAX). */
4851 real_maxval (&max
, neg
, mode
);
4852 if (! HONOR_NANS (mode
))
4853 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4854 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4855 temp
= fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4856 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4857 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
4866 /* If CODE with arguments ARG0 and ARG1 represents a single bit
4867 equality/inequality test, then return a simplified form of
4868 the test using shifts and logical operations. Otherwise return
4869 NULL. TYPE is the desired result type. */
4872 fold_single_bit_test (enum tree_code code
, tree arg0
, tree arg1
,
4875 /* If this is a TRUTH_NOT_EXPR, it may have a single bit test inside
4877 if (code
== TRUTH_NOT_EXPR
)
4879 code
= TREE_CODE (arg0
);
4880 if (code
!= NE_EXPR
&& code
!= EQ_EXPR
)
4883 /* Extract the arguments of the EQ/NE. */
4884 arg1
= TREE_OPERAND (arg0
, 1);
4885 arg0
= TREE_OPERAND (arg0
, 0);
4887 /* This requires us to invert the code. */
4888 code
= (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
);
4891 /* If this is testing a single bit, we can optimize the test. */
4892 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
4893 && TREE_CODE (arg0
) == BIT_AND_EXPR
&& integer_zerop (arg1
)
4894 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
4896 tree inner
= TREE_OPERAND (arg0
, 0);
4897 tree type
= TREE_TYPE (arg0
);
4898 int bitnum
= tree_log2 (TREE_OPERAND (arg0
, 1));
4899 enum machine_mode operand_mode
= TYPE_MODE (type
);
4901 tree signed_type
, unsigned_type
;
4904 /* If we have (A & C) != 0 where C is the sign bit of A, convert
4905 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
4906 arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1));
4907 if (arg00
!= NULL_TREE
)
4909 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
4910 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, result_type
,
4911 convert (stype
, arg00
),
4912 convert (stype
, integer_zero_node
)));
4915 /* At this point, we know that arg0 is not testing the sign bit. */
4916 if (TYPE_PRECISION (type
) - 1 == bitnum
)
4919 /* Otherwise we have (A & C) != 0 where C is a single bit,
4920 convert that into ((A >> C2) & 1). Where C2 = log2(C).
4921 Similarly for (A & C) == 0. */
4923 /* If INNER is a right shift of a constant and it plus BITNUM does
4924 not overflow, adjust BITNUM and INNER. */
4925 if (TREE_CODE (inner
) == RSHIFT_EXPR
4926 && TREE_CODE (TREE_OPERAND (inner
, 1)) == INTEGER_CST
4927 && TREE_INT_CST_HIGH (TREE_OPERAND (inner
, 1)) == 0
4928 && bitnum
< TYPE_PRECISION (type
)
4929 && 0 > compare_tree_int (TREE_OPERAND (inner
, 1),
4930 bitnum
- TYPE_PRECISION (type
)))
4932 bitnum
+= TREE_INT_CST_LOW (TREE_OPERAND (inner
, 1));
4933 inner
= TREE_OPERAND (inner
, 0);
4936 /* If we are going to be able to omit the AND below, we must do our
4937 operations as unsigned. If we must use the AND, we have a choice.
4938 Normally unsigned is faster, but for some machines signed is. */
4939 #ifdef LOAD_EXTEND_OP
4940 ops_unsigned
= (LOAD_EXTEND_OP (operand_mode
) == SIGN_EXTEND
? 0 : 1);
4945 signed_type
= (*lang_hooks
.types
.type_for_mode
) (operand_mode
, 0);
4946 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (operand_mode
, 1);
4949 inner
= build (RSHIFT_EXPR
, ops_unsigned
? unsigned_type
: signed_type
,
4950 inner
, size_int (bitnum
));
4952 if (code
== EQ_EXPR
)
4953 inner
= build (BIT_XOR_EXPR
, ops_unsigned
? unsigned_type
: signed_type
,
4954 inner
, integer_one_node
);
4956 /* Put the AND last so it can combine with more things. */
4957 inner
= build (BIT_AND_EXPR
, ops_unsigned
? unsigned_type
: signed_type
,
4958 inner
, integer_one_node
);
4960 /* Make sure to return the proper type. */
4961 if (TREE_TYPE (inner
) != result_type
)
4962 inner
= convert (result_type
, inner
);
4969 /* Perform constant folding and related simplification of EXPR.
4970 The related simplifications include x*1 => x, x*0 => 0, etc.,
4971 and application of the associative law.
4972 NOP_EXPR conversions may be removed freely (as long as we
4973 are careful not to change the C type of the overall expression)
4974 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4975 but we can constant-fold them if they have constant operands. */
4977 #ifdef ENABLE_FOLD_CHECKING
4978 # define fold(x) fold_1 (x)
4979 static tree
fold_1 (tree
);
4985 tree t
= expr
, orig_t
;
4986 tree t1
= NULL_TREE
;
4988 tree type
= TREE_TYPE (expr
);
4989 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4990 enum tree_code code
= TREE_CODE (t
);
4991 int kind
= TREE_CODE_CLASS (code
);
4993 /* WINS will be nonzero when the switch is done
4994 if all operands are constant. */
4997 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4998 Likewise for a SAVE_EXPR that's already been evaluated. */
4999 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
5002 /* Return right away if a constant. */
5006 #ifdef MAX_INTEGER_COMPUTATION_MODE
5007 check_max_integer_computation_mode (expr
);
5011 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
5015 /* Special case for conversion ops that can have fixed point args. */
5016 arg0
= TREE_OPERAND (t
, 0);
5018 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
5020 STRIP_SIGN_NOPS (arg0
);
5022 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
5023 subop
= TREE_REALPART (arg0
);
5027 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
5028 && TREE_CODE (subop
) != REAL_CST
5030 /* Note that TREE_CONSTANT isn't enough:
5031 static var addresses are constant but we can't
5032 do arithmetic on them. */
5035 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
5037 int len
= first_rtl_op (code
);
5039 for (i
= 0; i
< len
; i
++)
5041 tree op
= TREE_OPERAND (t
, i
);
5045 continue; /* Valid for CALL_EXPR, at least. */
5047 if (kind
== '<' || code
== RSHIFT_EXPR
)
5049 /* Signedness matters here. Perhaps we can refine this
5051 STRIP_SIGN_NOPS (op
);
5054 /* Strip any conversions that don't change the mode. */
5057 if (TREE_CODE (op
) == COMPLEX_CST
)
5058 subop
= TREE_REALPART (op
);
5062 if (TREE_CODE (subop
) != INTEGER_CST
5063 && TREE_CODE (subop
) != REAL_CST
)
5064 /* Note that TREE_CONSTANT isn't enough:
5065 static var addresses are constant but we can't
5066 do arithmetic on them. */
5076 /* If this is a commutative operation, and ARG0 is a constant, move it
5077 to ARG1 to reduce the number of tests below. */
5078 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
5079 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
5080 || code
== BIT_AND_EXPR
)
5081 && ((TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) != INTEGER_CST
)
5082 || (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) != REAL_CST
)))
5084 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
5088 TREE_OPERAND (t
, 0) = arg0
;
5089 TREE_OPERAND (t
, 1) = arg1
;
5092 /* Now WINS is set as described above,
5093 ARG0 is the first operand of EXPR,
5094 and ARG1 is the second operand (if it has more than one operand).
5096 First check for cases where an arithmetic operation is applied to a
5097 compound, conditional, or comparison operation. Push the arithmetic
5098 operation inside the compound or conditional to see if any folding
5099 can then be done. Convert comparison to conditional for this purpose.
5100 The also optimizes non-constant cases that used to be done in
5103 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5104 one of the operands is a comparison and the other is a comparison, a
5105 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5106 code below would make the expression more complex. Change it to a
5107 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5108 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5110 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5111 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5112 && ((truth_value_p (TREE_CODE (arg0
))
5113 && (truth_value_p (TREE_CODE (arg1
))
5114 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5115 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5116 || (truth_value_p (TREE_CODE (arg1
))
5117 && (truth_value_p (TREE_CODE (arg0
))
5118 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5119 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5121 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5122 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5126 if (code
== EQ_EXPR
)
5127 t
= invert_truthvalue (t
);
5132 if (TREE_CODE_CLASS (code
) == '1')
5134 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5135 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5136 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5137 else if (TREE_CODE (arg0
) == COND_EXPR
)
5139 tree arg01
= TREE_OPERAND (arg0
, 1);
5140 tree arg02
= TREE_OPERAND (arg0
, 2);
5141 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
5142 arg01
= fold (build1 (code
, type
, arg01
));
5143 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
5144 arg02
= fold (build1 (code
, type
, arg02
));
5145 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5148 /* If this was a conversion, and all we did was to move into
5149 inside the COND_EXPR, bring it back out. But leave it if
5150 it is a conversion from integer to integer and the
5151 result precision is no wider than a word since such a
5152 conversion is cheap and may be optimized away by combine,
5153 while it couldn't if it were outside the COND_EXPR. Then return
5154 so we don't get into an infinite recursion loop taking the
5155 conversion out and then back in. */
5157 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5158 || code
== NON_LVALUE_EXPR
)
5159 && TREE_CODE (t
) == COND_EXPR
5160 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5161 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5162 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
5163 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
5164 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5165 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5166 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5168 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5169 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5170 t
= build1 (code
, type
,
5172 TREE_TYPE (TREE_OPERAND
5173 (TREE_OPERAND (t
, 1), 0)),
5174 TREE_OPERAND (t
, 0),
5175 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5176 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5179 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5180 return fold (build (COND_EXPR
, type
, arg0
,
5181 fold (build1 (code
, type
, integer_one_node
)),
5182 fold (build1 (code
, type
, integer_zero_node
))));
5184 else if (TREE_CODE_CLASS (code
) == '<'
5185 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5186 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5187 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5188 else if (TREE_CODE_CLASS (code
) == '<'
5189 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5190 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5191 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5192 else if (TREE_CODE_CLASS (code
) == '2'
5193 || TREE_CODE_CLASS (code
) == '<')
5195 if (TREE_CODE (arg1
) == COMPOUND_EXPR
5196 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
5197 && ! TREE_SIDE_EFFECTS (arg0
))
5198 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5199 fold (build (code
, type
,
5200 arg0
, TREE_OPERAND (arg1
, 1))));
5201 else if ((TREE_CODE (arg1
) == COND_EXPR
5202 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5203 && TREE_CODE_CLASS (code
) != '<'))
5204 && (TREE_CODE (arg0
) != COND_EXPR
5205 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5206 && (! TREE_SIDE_EFFECTS (arg0
)
5207 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5208 && ! CONTAINS_PLACEHOLDER_P (arg0
))))
5210 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5211 /*cond_first_p=*/0);
5212 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5213 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5214 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5215 else if ((TREE_CODE (arg0
) == COND_EXPR
5216 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5217 && TREE_CODE_CLASS (code
) != '<'))
5218 && (TREE_CODE (arg1
) != COND_EXPR
5219 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5220 && (! TREE_SIDE_EFFECTS (arg1
)
5221 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5222 && ! CONTAINS_PLACEHOLDER_P (arg1
))))
5224 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5225 /*cond_first_p=*/1);
5239 return fold (DECL_INITIAL (t
));
5244 case FIX_TRUNC_EXPR
:
5245 /* Other kinds of FIX are not handled properly by fold_convert. */
5247 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5248 return TREE_OPERAND (t
, 0);
5250 /* Handle cases of two conversions in a row. */
5251 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5252 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5254 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5255 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5256 tree final_type
= TREE_TYPE (t
);
5257 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5258 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5259 int inside_float
= FLOAT_TYPE_P (inside_type
);
5260 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5261 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5262 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5263 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5264 int inter_float
= FLOAT_TYPE_P (inter_type
);
5265 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5266 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5267 int final_int
= INTEGRAL_TYPE_P (final_type
);
5268 int final_ptr
= POINTER_TYPE_P (final_type
);
5269 int final_float
= FLOAT_TYPE_P (final_type
);
5270 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5271 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5273 /* In addition to the cases of two conversions in a row
5274 handled below, if we are converting something to its own
5275 type via an object of identical or wider precision, neither
5276 conversion is needed. */
5277 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5278 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5279 && inter_prec
>= final_prec
)
5280 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5282 /* Likewise, if the intermediate and final types are either both
5283 float or both integer, we don't need the middle conversion if
5284 it is wider than the final type and doesn't change the signedness
5285 (for integers). Avoid this if the final type is a pointer
5286 since then we sometimes need the inner conversion. Likewise if
5287 the outer has a precision not equal to the size of its mode. */
5288 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5289 || (inter_float
&& inside_float
))
5290 && inter_prec
>= inside_prec
5291 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5292 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5293 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5295 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5297 /* If we have a sign-extension of a zero-extended value, we can
5298 replace that by a single zero-extension. */
5299 if (inside_int
&& inter_int
&& final_int
5300 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5301 && inside_unsignedp
&& !inter_unsignedp
)
5302 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5304 /* Two conversions in a row are not needed unless:
5305 - some conversion is floating-point (overstrict for now), or
5306 - the intermediate type is narrower than both initial and
5308 - the intermediate type and innermost type differ in signedness,
5309 and the outermost type is wider than the intermediate, or
5310 - the initial type is a pointer type and the precisions of the
5311 intermediate and final types differ, or
5312 - the final type is a pointer type and the precisions of the
5313 initial and intermediate types differ. */
5314 if (! inside_float
&& ! inter_float
&& ! final_float
5315 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5316 && ! (inside_int
&& inter_int
5317 && inter_unsignedp
!= inside_unsignedp
5318 && inter_prec
< final_prec
)
5319 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5320 == (final_unsignedp
&& final_prec
> inter_prec
))
5321 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5322 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5323 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5324 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5326 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5329 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5330 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5331 /* Detect assigning a bitfield. */
5332 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5333 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5335 /* Don't leave an assignment inside a conversion
5336 unless assigning a bitfield. */
5337 tree prev
= TREE_OPERAND (t
, 0);
5340 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5341 /* First do the assignment, then return converted constant. */
5342 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5347 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5348 constants (if x has signed type, the sign bit cannot be set
5349 in c). This folds extension into the BIT_AND_EXPR. */
5350 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5351 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5352 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5353 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5355 tree
and = TREE_OPERAND (t
, 0);
5356 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5359 if (TREE_UNSIGNED (TREE_TYPE (and))
5360 || (TYPE_PRECISION (TREE_TYPE (t
))
5361 <= TYPE_PRECISION (TREE_TYPE (and))))
5363 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5364 <= HOST_BITS_PER_WIDE_INT
5365 && host_integerp (and1
, 1))
5367 unsigned HOST_WIDE_INT cst
;
5369 cst
= tree_low_cst (and1
, 1);
5370 cst
&= (HOST_WIDE_INT
) -1
5371 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5372 change
= (cst
== 0);
5373 #ifdef LOAD_EXTEND_OP
5375 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5378 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5379 and0
= convert (uns
, and0
);
5380 and1
= convert (uns
, and1
);
5385 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5386 convert (TREE_TYPE (t
), and0
),
5387 convert (TREE_TYPE (t
), and1
)));
5392 if (TREE_CONSTANT (t
) != TREE_CONSTANT (arg0
))
5396 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5400 return fold_convert (t
, arg0
);
5402 case VIEW_CONVERT_EXPR
:
5403 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5404 return build1 (VIEW_CONVERT_EXPR
, type
,
5405 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5409 if (TREE_CODE (arg0
) == CONSTRUCTOR
5410 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
5412 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5419 if (TREE_CONSTANT (t
) != wins
)
5423 TREE_CONSTANT (t
) = wins
;
5430 if (TREE_CODE (arg0
) == INTEGER_CST
)
5432 unsigned HOST_WIDE_INT low
;
5434 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5435 TREE_INT_CST_HIGH (arg0
),
5437 t
= build_int_2 (low
, high
);
5438 TREE_TYPE (t
) = type
;
5440 = (TREE_OVERFLOW (arg0
)
5441 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5442 TREE_CONSTANT_OVERFLOW (t
)
5443 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5445 else if (TREE_CODE (arg0
) == REAL_CST
)
5446 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5448 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5449 return TREE_OPERAND (arg0
, 0);
5450 /* Convert -((double)float) into (double)(-float). */
5451 else if (TREE_CODE (arg0
) == NOP_EXPR
5452 && TREE_CODE (type
) == REAL_TYPE
)
5454 tree targ0
= strip_float_extensions (arg0
);
5456 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (targ0
), targ0
));
5460 /* Convert - (a - b) to (b - a) for non-floating-point. */
5461 else if (TREE_CODE (arg0
) == MINUS_EXPR
5462 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5463 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5464 TREE_OPERAND (arg0
, 0));
5466 /* Convert -f(x) into f(-x) where f is sin, tan or atan. */
5467 switch (builtin_mathfn_code (arg0
))
5476 case BUILT_IN_ATANF
:
5477 case BUILT_IN_ATANL
:
5478 if (negate_expr_p (TREE_VALUE (TREE_OPERAND (arg0
, 1))))
5480 tree fndecl
, arg
, arglist
;
5482 fndecl
= get_callee_fndecl (arg0
);
5483 arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5484 arg
= fold (build1 (NEGATE_EXPR
, type
, arg
));
5485 arglist
= build_tree_list (NULL_TREE
, arg
);
5486 return build_function_call_expr (fndecl
, arglist
);
5498 if (TREE_CODE (arg0
) == INTEGER_CST
)
5500 /* If the value is unsigned, then the absolute value is
5501 the same as the ordinary value. */
5502 if (TREE_UNSIGNED (type
))
5504 /* Similarly, if the value is non-negative. */
5505 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5507 /* If the value is negative, then the absolute value is
5511 unsigned HOST_WIDE_INT low
;
5513 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5514 TREE_INT_CST_HIGH (arg0
),
5516 t
= build_int_2 (low
, high
);
5517 TREE_TYPE (t
) = type
;
5519 = (TREE_OVERFLOW (arg0
)
5520 | force_fit_type (t
, overflow
));
5521 TREE_CONSTANT_OVERFLOW (t
)
5522 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5525 else if (TREE_CODE (arg0
) == REAL_CST
)
5527 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5528 t
= build_real (type
,
5529 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5532 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5533 return fold (build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0)));
5534 /* Convert fabs((double)float) into (double)fabsf(float). */
5535 else if (TREE_CODE (arg0
) == NOP_EXPR
5536 && TREE_CODE (type
) == REAL_TYPE
)
5538 tree targ0
= strip_float_extensions (arg0
);
5540 return convert (type
, fold (build1 (ABS_EXPR
, TREE_TYPE (targ0
),
5543 else if (tree_expr_nonnegative_p (arg0
))
5548 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5549 return convert (type
, arg0
);
5550 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5551 return build (COMPLEX_EXPR
, type
,
5552 TREE_OPERAND (arg0
, 0),
5553 negate_expr (TREE_OPERAND (arg0
, 1)));
5554 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5555 return build_complex (type
, TREE_REALPART (arg0
),
5556 negate_expr (TREE_IMAGPART (arg0
)));
5557 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5558 return fold (build (TREE_CODE (arg0
), type
,
5559 fold (build1 (CONJ_EXPR
, type
,
5560 TREE_OPERAND (arg0
, 0))),
5561 fold (build1 (CONJ_EXPR
,
5562 type
, TREE_OPERAND (arg0
, 1)))));
5563 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5564 return TREE_OPERAND (arg0
, 0);
5570 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5571 ~ TREE_INT_CST_HIGH (arg0
));
5572 TREE_TYPE (t
) = type
;
5573 force_fit_type (t
, 0);
5574 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5575 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5577 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5578 return TREE_OPERAND (arg0
, 0);
5582 /* A + (-B) -> A - B */
5583 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5584 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5585 /* (-A) + B -> B - A */
5586 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5587 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5588 else if (! FLOAT_TYPE_P (type
))
5590 if (integer_zerop (arg1
))
5591 return non_lvalue (convert (type
, arg0
));
5593 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5594 with a constant, and the two constants have no bits in common,
5595 we should treat this as a BIT_IOR_EXPR since this may produce more
5597 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5598 && TREE_CODE (arg1
) == BIT_AND_EXPR
5599 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5600 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5601 && integer_zerop (const_binop (BIT_AND_EXPR
,
5602 TREE_OPERAND (arg0
, 1),
5603 TREE_OPERAND (arg1
, 1), 0)))
5605 code
= BIT_IOR_EXPR
;
5609 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5610 (plus (plus (mult) (mult)) (foo)) so that we can
5611 take advantage of the factoring cases below. */
5612 if ((TREE_CODE (arg0
) == PLUS_EXPR
5613 && TREE_CODE (arg1
) == MULT_EXPR
)
5614 || (TREE_CODE (arg1
) == PLUS_EXPR
5615 && TREE_CODE (arg0
) == MULT_EXPR
))
5617 tree parg0
, parg1
, parg
, marg
;
5619 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5620 parg
= arg0
, marg
= arg1
;
5622 parg
= arg1
, marg
= arg0
;
5623 parg0
= TREE_OPERAND (parg
, 0);
5624 parg1
= TREE_OPERAND (parg
, 1);
5628 if (TREE_CODE (parg0
) == MULT_EXPR
5629 && TREE_CODE (parg1
) != MULT_EXPR
)
5630 return fold (build (PLUS_EXPR
, type
,
5631 fold (build (PLUS_EXPR
, type
,
5632 convert (type
, parg0
),
5633 convert (type
, marg
))),
5634 convert (type
, parg1
)));
5635 if (TREE_CODE (parg0
) != MULT_EXPR
5636 && TREE_CODE (parg1
) == MULT_EXPR
)
5637 return fold (build (PLUS_EXPR
, type
,
5638 fold (build (PLUS_EXPR
, type
,
5639 convert (type
, parg1
),
5640 convert (type
, marg
))),
5641 convert (type
, parg0
)));
5644 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5646 tree arg00
, arg01
, arg10
, arg11
;
5647 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5649 /* (A * C) + (B * C) -> (A+B) * C.
5650 We are most concerned about the case where C is a constant,
5651 but other combinations show up during loop reduction. Since
5652 it is not difficult, try all four possibilities. */
5654 arg00
= TREE_OPERAND (arg0
, 0);
5655 arg01
= TREE_OPERAND (arg0
, 1);
5656 arg10
= TREE_OPERAND (arg1
, 0);
5657 arg11
= TREE_OPERAND (arg1
, 1);
5660 if (operand_equal_p (arg01
, arg11
, 0))
5661 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5662 else if (operand_equal_p (arg00
, arg10
, 0))
5663 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5664 else if (operand_equal_p (arg00
, arg11
, 0))
5665 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5666 else if (operand_equal_p (arg01
, arg10
, 0))
5667 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5669 /* No identical multiplicands; see if we can find a common
5670 power-of-two factor in non-power-of-two multiplies. This
5671 can help in multi-dimensional array access. */
5672 else if (TREE_CODE (arg01
) == INTEGER_CST
5673 && TREE_CODE (arg11
) == INTEGER_CST
5674 && TREE_INT_CST_HIGH (arg01
) == 0
5675 && TREE_INT_CST_HIGH (arg11
) == 0)
5677 HOST_WIDE_INT int01
, int11
, tmp
;
5678 int01
= TREE_INT_CST_LOW (arg01
);
5679 int11
= TREE_INT_CST_LOW (arg11
);
5681 /* Move min of absolute values to int11. */
5682 if ((int01
>= 0 ? int01
: -int01
)
5683 < (int11
>= 0 ? int11
: -int11
))
5685 tmp
= int01
, int01
= int11
, int11
= tmp
;
5686 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5687 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5690 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5692 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5693 build_int_2 (int01
/ int11
, 0)));
5700 return fold (build (MULT_EXPR
, type
,
5701 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5707 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5708 if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
5709 return non_lvalue (convert (type
, arg0
));
5711 /* Likewise if the operands are reversed. */
5712 if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5713 return non_lvalue (convert (type
, arg1
));
5715 /* Convert x+x into x*2.0. */
5716 if (operand_equal_p (arg0
, arg1
, 0))
5717 return fold (build (MULT_EXPR
, type
, arg0
,
5718 build_real (type
, dconst2
)));
5720 /* Convert x*c+x into x*(c+1). */
5721 if (flag_unsafe_math_optimizations
5722 && TREE_CODE (arg0
) == MULT_EXPR
5723 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
5724 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
5725 && operand_equal_p (TREE_OPERAND (arg0
, 0), arg1
, 0))
5729 c
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
5730 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
5731 return fold (build (MULT_EXPR
, type
, arg1
,
5732 build_real (type
, c
)));
5735 /* Convert x+x*c into x*(c+1). */
5736 if (flag_unsafe_math_optimizations
5737 && TREE_CODE (arg1
) == MULT_EXPR
5738 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
5739 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
5740 && operand_equal_p (TREE_OPERAND (arg1
, 0), arg0
, 0))
5744 c
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
5745 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
5746 return fold (build (MULT_EXPR
, type
, arg0
,
5747 build_real (type
, c
)));
5750 /* Convert x*c1+x*c2 into x*(c1+c2). */
5751 if (flag_unsafe_math_optimizations
5752 && TREE_CODE (arg0
) == MULT_EXPR
5753 && TREE_CODE (arg1
) == MULT_EXPR
5754 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
5755 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg0
, 1))
5756 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == REAL_CST
5757 && ! TREE_CONSTANT_OVERFLOW (TREE_OPERAND (arg1
, 1))
5758 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5759 TREE_OPERAND (arg1
, 0), 0))
5761 REAL_VALUE_TYPE c1
, c2
;
5763 c1
= TREE_REAL_CST (TREE_OPERAND (arg0
, 1));
5764 c2
= TREE_REAL_CST (TREE_OPERAND (arg1
, 1));
5765 real_arithmetic (&c1
, PLUS_EXPR
, &c1
, &c2
);
5766 return fold (build (MULT_EXPR
, type
,
5767 TREE_OPERAND (arg0
, 0),
5768 build_real (type
, c1
)));
5773 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5774 is a rotate of A by C1 bits. */
5775 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5776 is a rotate of A by B bits. */
5778 enum tree_code code0
, code1
;
5779 code0
= TREE_CODE (arg0
);
5780 code1
= TREE_CODE (arg1
);
5781 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5782 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5783 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5784 TREE_OPERAND (arg1
, 0), 0)
5785 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5787 tree tree01
, tree11
;
5788 enum tree_code code01
, code11
;
5790 tree01
= TREE_OPERAND (arg0
, 1);
5791 tree11
= TREE_OPERAND (arg1
, 1);
5792 STRIP_NOPS (tree01
);
5793 STRIP_NOPS (tree11
);
5794 code01
= TREE_CODE (tree01
);
5795 code11
= TREE_CODE (tree11
);
5796 if (code01
== INTEGER_CST
5797 && code11
== INTEGER_CST
5798 && TREE_INT_CST_HIGH (tree01
) == 0
5799 && TREE_INT_CST_HIGH (tree11
) == 0
5800 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5801 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5802 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5803 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5804 else if (code11
== MINUS_EXPR
)
5806 tree tree110
, tree111
;
5807 tree110
= TREE_OPERAND (tree11
, 0);
5808 tree111
= TREE_OPERAND (tree11
, 1);
5809 STRIP_NOPS (tree110
);
5810 STRIP_NOPS (tree111
);
5811 if (TREE_CODE (tree110
) == INTEGER_CST
5812 && 0 == compare_tree_int (tree110
,
5814 (TREE_TYPE (TREE_OPERAND
5816 && operand_equal_p (tree01
, tree111
, 0))
5817 return build ((code0
== LSHIFT_EXPR
5820 type
, TREE_OPERAND (arg0
, 0), tree01
);
5822 else if (code01
== MINUS_EXPR
)
5824 tree tree010
, tree011
;
5825 tree010
= TREE_OPERAND (tree01
, 0);
5826 tree011
= TREE_OPERAND (tree01
, 1);
5827 STRIP_NOPS (tree010
);
5828 STRIP_NOPS (tree011
);
5829 if (TREE_CODE (tree010
) == INTEGER_CST
5830 && 0 == compare_tree_int (tree010
,
5832 (TREE_TYPE (TREE_OPERAND
5834 && operand_equal_p (tree11
, tree011
, 0))
5835 return build ((code0
!= LSHIFT_EXPR
5838 type
, TREE_OPERAND (arg0
, 0), tree11
);
5844 /* In most languages, can't associate operations on floats through
5845 parentheses. Rather than remember where the parentheses were, we
5846 don't associate floats at all, unless the user has specified
5847 -funsafe-math-optimizations. */
5850 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5852 tree var0
, con0
, lit0
, minus_lit0
;
5853 tree var1
, con1
, lit1
, minus_lit1
;
5855 /* Split both trees into variables, constants, and literals. Then
5856 associate each group together, the constants with literals,
5857 then the result with variables. This increases the chances of
5858 literals being recombined later and of generating relocatable
5859 expressions for the sum of a constant and literal. */
5860 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
5861 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
5862 code
== MINUS_EXPR
);
5864 /* Only do something if we found more than two objects. Otherwise,
5865 nothing has changed and we risk infinite recursion. */
5866 if (2 < ((var0
!= 0) + (var1
!= 0)
5867 + (con0
!= 0) + (con1
!= 0)
5868 + (lit0
!= 0) + (lit1
!= 0)
5869 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
5871 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5872 if (code
== MINUS_EXPR
)
5875 var0
= associate_trees (var0
, var1
, code
, type
);
5876 con0
= associate_trees (con0
, con1
, code
, type
);
5877 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5878 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
5880 /* Preserve the MINUS_EXPR if the negative part of the literal is
5881 greater than the positive part. Otherwise, the multiplicative
5882 folding code (i.e extract_muldiv) may be fooled in case
5883 unsigned constants are subtracted, like in the following
5884 example: ((X*2 + 4) - 8U)/2. */
5885 if (minus_lit0
&& lit0
)
5887 if (tree_int_cst_lt (lit0
, minus_lit0
))
5889 minus_lit0
= associate_trees (minus_lit0
, lit0
,
5895 lit0
= associate_trees (lit0
, minus_lit0
,
5903 return convert (type
, associate_trees (var0
, minus_lit0
,
5907 con0
= associate_trees (con0
, minus_lit0
,
5909 return convert (type
, associate_trees (var0
, con0
,
5914 con0
= associate_trees (con0
, lit0
, code
, type
);
5915 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5921 t1
= const_binop (code
, arg0
, arg1
, 0);
5922 if (t1
!= NULL_TREE
)
5924 /* The return value should always have
5925 the same type as the original expression. */
5926 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5927 t1
= convert (TREE_TYPE (t
), t1
);
5934 /* A - (-B) -> A + B */
5935 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5936 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5937 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5938 if (TREE_CODE (arg0
) == NEGATE_EXPR
5939 && (FLOAT_TYPE_P (type
)
5940 || (INTEGRAL_TYPE_P (type
) && flag_wrapv
&& !flag_trapv
))
5941 && negate_expr_p (arg1
)
5942 && (! TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
5943 && (! TREE_SIDE_EFFECTS (arg1
) || TREE_CONSTANT (arg0
)))
5944 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
5945 TREE_OPERAND (arg0
, 0)));
5947 if (! FLOAT_TYPE_P (type
))
5949 if (! wins
&& integer_zerop (arg0
))
5950 return negate_expr (convert (type
, arg1
));
5951 if (integer_zerop (arg1
))
5952 return non_lvalue (convert (type
, arg0
));
5954 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5955 about the case where C is a constant, just try one of the
5956 four possibilities. */
5958 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5959 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5960 TREE_OPERAND (arg1
, 1), 0))
5961 return fold (build (MULT_EXPR
, type
,
5962 fold (build (MINUS_EXPR
, type
,
5963 TREE_OPERAND (arg0
, 0),
5964 TREE_OPERAND (arg1
, 0))),
5965 TREE_OPERAND (arg0
, 1)));
5967 /* Fold A - (A & B) into ~B & A. */
5968 if (!TREE_SIDE_EFFECTS (arg0
)
5969 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
5971 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
5972 return fold (build (BIT_AND_EXPR
, type
,
5973 fold (build1 (BIT_NOT_EXPR
, type
,
5974 TREE_OPERAND (arg1
, 0))),
5976 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
5977 return fold (build (BIT_AND_EXPR
, type
,
5978 fold (build1 (BIT_NOT_EXPR
, type
,
5979 TREE_OPERAND (arg1
, 1))),
5984 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5985 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
5986 return non_lvalue (convert (type
, arg0
));
5988 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5989 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5990 (-ARG1 + ARG0) reduces to -ARG1. */
5991 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5992 return negate_expr (convert (type
, arg1
));
5994 /* Fold &x - &x. This can happen from &x.foo - &x.
5995 This is unsafe for certain floats even in non-IEEE formats.
5996 In IEEE, it is unsafe because it does wrong for NaNs.
5997 Also note that operand_equal_p is always false if an operand
6000 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
6001 && operand_equal_p (arg0
, arg1
, 0))
6002 return convert (type
, integer_zero_node
);
6007 /* (-A) * (-B) -> A * B */
6008 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
6009 return fold (build (MULT_EXPR
, type
,
6010 TREE_OPERAND (arg0
, 0),
6011 negate_expr (arg1
)));
6012 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
6013 return fold (build (MULT_EXPR
, type
,
6015 TREE_OPERAND (arg1
, 0)));
6017 if (! FLOAT_TYPE_P (type
))
6019 if (integer_zerop (arg1
))
6020 return omit_one_operand (type
, arg1
, arg0
);
6021 if (integer_onep (arg1
))
6022 return non_lvalue (convert (type
, arg0
));
6024 /* (a * (1 << b)) is (a << b) */
6025 if (TREE_CODE (arg1
) == LSHIFT_EXPR
6026 && integer_onep (TREE_OPERAND (arg1
, 0)))
6027 return fold (build (LSHIFT_EXPR
, type
, arg0
,
6028 TREE_OPERAND (arg1
, 1)));
6029 if (TREE_CODE (arg0
) == LSHIFT_EXPR
6030 && integer_onep (TREE_OPERAND (arg0
, 0)))
6031 return fold (build (LSHIFT_EXPR
, type
, arg1
,
6032 TREE_OPERAND (arg0
, 1)));
6034 if (TREE_CODE (arg1
) == INTEGER_CST
6035 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
6036 convert (type
, arg1
),
6038 return convert (type
, tem
);
6043 /* Maybe fold x * 0 to 0. The expressions aren't the same
6044 when x is NaN, since x * 0 is also NaN. Nor are they the
6045 same in modes with signed zeros, since multiplying a
6046 negative value by 0 gives -0, not +0. */
6047 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
6048 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
6049 && real_zerop (arg1
))
6050 return omit_one_operand (type
, arg1
, arg0
);
6051 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
6052 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6053 && real_onep (arg1
))
6054 return non_lvalue (convert (type
, arg0
));
6056 /* Transform x * -1.0 into -x. */
6057 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6058 && real_minus_onep (arg1
))
6059 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
6061 if (flag_unsafe_math_optimizations
)
6063 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6064 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6066 /* Optimizations of sqrt(...)*sqrt(...). */
6067 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
6068 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
6069 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
6071 tree sqrtfn
, arg
, arglist
;
6072 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6073 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6075 /* Optimize sqrt(x)*sqrt(x) as x. */
6076 if (operand_equal_p (arg00
, arg10
, 0)
6077 && ! HONOR_SNANS (TYPE_MODE (type
)))
6080 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
6081 sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6082 arg
= fold (build (MULT_EXPR
, type
, arg00
, arg10
));
6083 arglist
= build_tree_list (NULL_TREE
, arg
);
6084 return build_function_call_expr (sqrtfn
, arglist
);
6087 /* Optimize exp(x)*exp(y) as exp(x+y). */
6088 if ((fcode0
== BUILT_IN_EXP
&& fcode1
== BUILT_IN_EXP
)
6089 || (fcode0
== BUILT_IN_EXPF
&& fcode1
== BUILT_IN_EXPF
)
6090 || (fcode0
== BUILT_IN_EXPL
&& fcode1
== BUILT_IN_EXPL
))
6092 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6093 tree arg
= build (PLUS_EXPR
, type
,
6094 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6095 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6096 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6097 return build_function_call_expr (expfn
, arglist
);
6100 /* Optimizations of pow(...)*pow(...). */
6101 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
6102 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
6103 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
6105 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6106 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
6108 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6109 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
6112 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
6113 if (operand_equal_p (arg01
, arg11
, 0))
6115 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6116 tree arg
= build (MULT_EXPR
, type
, arg00
, arg10
);
6117 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
6118 build_tree_list (NULL_TREE
,
6120 return build_function_call_expr (powfn
, arglist
);
6123 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
6124 if (operand_equal_p (arg00
, arg10
, 0))
6126 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6127 tree arg
= fold (build (PLUS_EXPR
, type
, arg01
, arg11
));
6128 tree arglist
= tree_cons (NULL_TREE
, arg00
,
6129 build_tree_list (NULL_TREE
,
6131 return build_function_call_expr (powfn
, arglist
);
6135 /* Optimize tan(x)*cos(x) as sin(x). */
6136 if (((fcode0
== BUILT_IN_TAN
&& fcode1
== BUILT_IN_COS
)
6137 || (fcode0
== BUILT_IN_TANF
&& fcode1
== BUILT_IN_COSF
)
6138 || (fcode0
== BUILT_IN_TANL
&& fcode1
== BUILT_IN_COSL
)
6139 || (fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_TAN
)
6140 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_TANF
)
6141 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_TANL
))
6142 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6143 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6151 sinfn
= implicit_built_in_decls
[BUILT_IN_SIN
];
6155 sinfn
= implicit_built_in_decls
[BUILT_IN_SINF
];
6159 sinfn
= implicit_built_in_decls
[BUILT_IN_SINL
];
6165 if (sinfn
!= NULL_TREE
)
6166 return build_function_call_expr (sinfn
,
6167 TREE_OPERAND (arg0
, 1));
6170 /* Optimize x*pow(x,c) as pow(x,c+1). */
6171 if (fcode1
== BUILT_IN_POW
6172 || fcode1
== BUILT_IN_POWF
6173 || fcode1
== BUILT_IN_POWL
)
6175 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6176 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
6178 if (TREE_CODE (arg11
) == REAL_CST
6179 && ! TREE_CONSTANT_OVERFLOW (arg11
)
6180 && operand_equal_p (arg0
, arg10
, 0))
6182 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6186 c
= TREE_REAL_CST (arg11
);
6187 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6188 arg
= build_real (type
, c
);
6189 arglist
= build_tree_list (NULL_TREE
, arg
);
6190 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
6191 return build_function_call_expr (powfn
, arglist
);
6195 /* Optimize pow(x,c)*x as pow(x,c+1). */
6196 if (fcode0
== BUILT_IN_POW
6197 || fcode0
== BUILT_IN_POWF
6198 || fcode0
== BUILT_IN_POWL
)
6200 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6201 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
6203 if (TREE_CODE (arg01
) == REAL_CST
6204 && ! TREE_CONSTANT_OVERFLOW (arg01
)
6205 && operand_equal_p (arg1
, arg00
, 0))
6207 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6211 c
= TREE_REAL_CST (arg01
);
6212 real_arithmetic (&c
, PLUS_EXPR
, &c
, &dconst1
);
6213 arg
= build_real (type
, c
);
6214 arglist
= build_tree_list (NULL_TREE
, arg
);
6215 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
6216 return build_function_call_expr (powfn
, arglist
);
6220 /* Optimize x*x as pow(x,2.0), which is expanded as x*x. */
6222 && operand_equal_p (arg0
, arg1
, 0))
6226 if (type
== double_type_node
)
6227 powfn
= implicit_built_in_decls
[BUILT_IN_POW
];
6228 else if (type
== float_type_node
)
6229 powfn
= implicit_built_in_decls
[BUILT_IN_POWF
];
6230 else if (type
== long_double_type_node
)
6231 powfn
= implicit_built_in_decls
[BUILT_IN_POWL
];
6237 tree arg
= build_real (type
, dconst2
);
6238 tree arglist
= build_tree_list (NULL_TREE
, arg
);
6239 arglist
= tree_cons (NULL_TREE
, arg0
, arglist
);
6240 return build_function_call_expr (powfn
, arglist
);
6249 if (integer_all_onesp (arg1
))
6250 return omit_one_operand (type
, arg1
, arg0
);
6251 if (integer_zerop (arg1
))
6252 return non_lvalue (convert (type
, arg0
));
6253 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6254 if (t1
!= NULL_TREE
)
6257 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
6259 This results in more efficient code for machines without a NAND
6260 instruction. Combine will canonicalize to the first form
6261 which will allow use of NAND instructions provided by the
6262 backend if they exist. */
6263 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6264 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6266 return fold (build1 (BIT_NOT_EXPR
, type
,
6267 build (BIT_AND_EXPR
, type
,
6268 TREE_OPERAND (arg0
, 0),
6269 TREE_OPERAND (arg1
, 0))));
6272 /* See if this can be simplified into a rotate first. If that
6273 is unsuccessful continue in the association code. */
6277 if (integer_zerop (arg1
))
6278 return non_lvalue (convert (type
, arg0
));
6279 if (integer_all_onesp (arg1
))
6280 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
6282 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6283 with a constant, and the two constants have no bits in common,
6284 we should treat this as a BIT_IOR_EXPR since this may produce more
6286 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6287 && TREE_CODE (arg1
) == BIT_AND_EXPR
6288 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6289 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
6290 && integer_zerop (const_binop (BIT_AND_EXPR
,
6291 TREE_OPERAND (arg0
, 1),
6292 TREE_OPERAND (arg1
, 1), 0)))
6294 code
= BIT_IOR_EXPR
;
6298 /* See if this can be simplified into a rotate first. If that
6299 is unsuccessful continue in the association code. */
6304 if (integer_all_onesp (arg1
))
6305 return non_lvalue (convert (type
, arg0
));
6306 if (integer_zerop (arg1
))
6307 return omit_one_operand (type
, arg1
, arg0
);
6308 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6309 if (t1
!= NULL_TREE
)
6311 /* Simplify ((int)c & 0377) into (int)c, if c is unsigned char. */
6312 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
6313 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6316 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
6318 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
6319 && (~TREE_INT_CST_LOW (arg1
)
6320 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
6321 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
6324 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6326 This results in more efficient code for machines without a NOR
6327 instruction. Combine will canonicalize to the first form
6328 which will allow use of NOR instructions provided by the
6329 backend if they exist. */
6330 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6331 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6333 return fold (build1 (BIT_NOT_EXPR
, type
,
6334 build (BIT_IOR_EXPR
, type
,
6335 TREE_OPERAND (arg0
, 0),
6336 TREE_OPERAND (arg1
, 0))));
6341 case BIT_ANDTC_EXPR
:
6342 if (integer_all_onesp (arg0
))
6343 return non_lvalue (convert (type
, arg1
));
6344 if (integer_zerop (arg0
))
6345 return omit_one_operand (type
, arg0
, arg1
);
6346 if (TREE_CODE (arg1
) == INTEGER_CST
)
6348 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
6349 code
= BIT_AND_EXPR
;
6355 /* Don't touch a floating-point divide by zero unless the mode
6356 of the constant can represent infinity. */
6357 if (TREE_CODE (arg1
) == REAL_CST
6358 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
6359 && real_zerop (arg1
))
6362 /* (-A) / (-B) -> A / B */
6363 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& negate_expr_p (arg1
))
6364 return fold (build (RDIV_EXPR
, type
,
6365 TREE_OPERAND (arg0
, 0),
6366 negate_expr (arg1
)));
6367 if (TREE_CODE (arg1
) == NEGATE_EXPR
&& negate_expr_p (arg0
))
6368 return fold (build (RDIV_EXPR
, type
,
6370 TREE_OPERAND (arg1
, 0)));
6372 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6373 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6374 && real_onep (arg1
))
6375 return non_lvalue (convert (type
, arg0
));
6377 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
6378 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6379 && real_minus_onep (arg1
))
6380 return non_lvalue (convert (type
, negate_expr (arg0
)));
6382 /* If ARG1 is a constant, we can convert this to a multiply by the
6383 reciprocal. This does not have the same rounding properties,
6384 so only do this if -funsafe-math-optimizations. We can actually
6385 always safely do it if ARG1 is a power of two, but it's hard to
6386 tell if it is or not in a portable manner. */
6387 if (TREE_CODE (arg1
) == REAL_CST
)
6389 if (flag_unsafe_math_optimizations
6390 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
6392 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6393 /* Find the reciprocal if optimizing and the result is exact. */
6397 r
= TREE_REAL_CST (arg1
);
6398 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
6400 tem
= build_real (type
, r
);
6401 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6405 /* Convert A/B/C to A/(B*C). */
6406 if (flag_unsafe_math_optimizations
6407 && TREE_CODE (arg0
) == RDIV_EXPR
)
6409 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6410 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
6413 /* Convert A/(B/C) to (A/B)*C. */
6414 if (flag_unsafe_math_optimizations
6415 && TREE_CODE (arg1
) == RDIV_EXPR
)
6417 return fold (build (MULT_EXPR
, type
,
6418 build (RDIV_EXPR
, type
, arg0
,
6419 TREE_OPERAND (arg1
, 0)),
6420 TREE_OPERAND (arg1
, 1)));
6423 if (flag_unsafe_math_optimizations
)
6425 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
6426 /* Optimize x/exp(y) into x*exp(-y). */
6427 if (fcode
== BUILT_IN_EXP
6428 || fcode
== BUILT_IN_EXPF
6429 || fcode
== BUILT_IN_EXPL
)
6431 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6432 tree arg
= build1 (NEGATE_EXPR
, type
,
6433 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6434 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6435 arg1
= build_function_call_expr (expfn
, arglist
);
6436 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6439 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6440 if (fcode
== BUILT_IN_POW
6441 || fcode
== BUILT_IN_POWF
6442 || fcode
== BUILT_IN_POWL
)
6444 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6445 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6446 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
6447 tree neg11
= fold (build1 (NEGATE_EXPR
, type
, arg11
));
6448 tree arglist
= tree_cons(NULL_TREE
, arg10
,
6449 build_tree_list (NULL_TREE
, neg11
));
6450 arg1
= build_function_call_expr (powfn
, arglist
);
6451 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6455 if (flag_unsafe_math_optimizations
)
6457 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
6458 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
6460 /* Optimize sin(x)/cos(x) as tan(x). */
6461 if (((fcode0
== BUILT_IN_SIN
&& fcode1
== BUILT_IN_COS
)
6462 || (fcode0
== BUILT_IN_SINF
&& fcode1
== BUILT_IN_COSF
)
6463 || (fcode0
== BUILT_IN_SINL
&& fcode1
== BUILT_IN_COSL
))
6464 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6465 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6469 if (fcode0
== BUILT_IN_SIN
)
6470 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6471 else if (fcode0
== BUILT_IN_SINF
)
6472 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6473 else if (fcode0
== BUILT_IN_SINL
)
6474 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6478 if (tanfn
!= NULL_TREE
)
6479 return build_function_call_expr (tanfn
,
6480 TREE_OPERAND (arg0
, 1));
6483 /* Optimize cos(x)/sin(x) as 1.0/tan(x). */
6484 if (((fcode0
== BUILT_IN_COS
&& fcode1
== BUILT_IN_SIN
)
6485 || (fcode0
== BUILT_IN_COSF
&& fcode1
== BUILT_IN_SINF
)
6486 || (fcode0
== BUILT_IN_COSL
&& fcode1
== BUILT_IN_SINL
))
6487 && operand_equal_p (TREE_VALUE (TREE_OPERAND (arg0
, 1)),
6488 TREE_VALUE (TREE_OPERAND (arg1
, 1)), 0))
6492 if (fcode0
== BUILT_IN_COS
)
6493 tanfn
= implicit_built_in_decls
[BUILT_IN_TAN
];
6494 else if (fcode0
== BUILT_IN_COSF
)
6495 tanfn
= implicit_built_in_decls
[BUILT_IN_TANF
];
6496 else if (fcode0
== BUILT_IN_COSL
)
6497 tanfn
= implicit_built_in_decls
[BUILT_IN_TANL
];
6501 if (tanfn
!= NULL_TREE
)
6503 tree tmp
= TREE_OPERAND (arg0
, 1);
6504 tmp
= build_function_call_expr (tanfn
, tmp
);
6505 return fold (build (RDIV_EXPR
, type
,
6506 build_real (type
, dconst1
),
6511 /* Optimize pow(x,c)/x as pow(x,c-1). */
6512 if (fcode0
== BUILT_IN_POW
6513 || fcode0
== BUILT_IN_POWF
6514 || fcode0
== BUILT_IN_POWL
)
6516 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
6517 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
, 1)));
6518 if (TREE_CODE (arg01
) == REAL_CST
6519 && ! TREE_CONSTANT_OVERFLOW (arg01
)
6520 && operand_equal_p (arg1
, arg00
, 0))
6522 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6526 c
= TREE_REAL_CST (arg01
);
6527 real_arithmetic (&c
, MINUS_EXPR
, &c
, &dconst1
);
6528 arg
= build_real (type
, c
);
6529 arglist
= build_tree_list (NULL_TREE
, arg
);
6530 arglist
= tree_cons (NULL_TREE
, arg1
, arglist
);
6531 return build_function_call_expr (powfn
, arglist
);
6537 case TRUNC_DIV_EXPR
:
6538 case ROUND_DIV_EXPR
:
6539 case FLOOR_DIV_EXPR
:
6541 case EXACT_DIV_EXPR
:
6542 if (integer_onep (arg1
))
6543 return non_lvalue (convert (type
, arg0
));
6544 if (integer_zerop (arg1
))
6547 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6548 operation, EXACT_DIV_EXPR.
6550 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6551 At one time others generated faster code, it's not clear if they do
6552 after the last round to changes to the DIV code in expmed.c. */
6553 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6554 && multiple_of_p (type
, arg0
, arg1
))
6555 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6557 if (TREE_CODE (arg1
) == INTEGER_CST
6558 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6560 return convert (type
, tem
);
6565 case FLOOR_MOD_EXPR
:
6566 case ROUND_MOD_EXPR
:
6567 case TRUNC_MOD_EXPR
:
6568 if (integer_onep (arg1
))
6569 return omit_one_operand (type
, integer_zero_node
, arg0
);
6570 if (integer_zerop (arg1
))
6573 if (TREE_CODE (arg1
) == INTEGER_CST
6574 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6576 return convert (type
, tem
);
6582 if (integer_all_onesp (arg0
))
6583 return omit_one_operand (type
, arg0
, arg1
);
6587 /* Optimize -1 >> x for arithmetic right shifts. */
6588 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
6589 return omit_one_operand (type
, arg0
, arg1
);
6590 /* ... fall through ... */
6594 if (integer_zerop (arg1
))
6595 return non_lvalue (convert (type
, arg0
));
6596 if (integer_zerop (arg0
))
6597 return omit_one_operand (type
, arg0
, arg1
);
6599 /* Since negative shift count is not well-defined,
6600 don't try to compute it in the compiler. */
6601 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6603 /* Rewrite an LROTATE_EXPR by a constant into an
6604 RROTATE_EXPR by a new constant. */
6605 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6609 TREE_SET_CODE (t
, RROTATE_EXPR
);
6610 code
= RROTATE_EXPR
;
6611 TREE_OPERAND (t
, 1) = arg1
6614 convert (TREE_TYPE (arg1
),
6615 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6617 if (tree_int_cst_sgn (arg1
) < 0)
6621 /* If we have a rotate of a bit operation with the rotate count and
6622 the second operand of the bit operation both constant,
6623 permute the two operations. */
6624 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6625 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6626 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6627 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6628 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6629 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6630 return fold (build (TREE_CODE (arg0
), type
,
6631 fold (build (code
, type
,
6632 TREE_OPERAND (arg0
, 0), arg1
)),
6633 fold (build (code
, type
,
6634 TREE_OPERAND (arg0
, 1), arg1
))));
6636 /* Two consecutive rotates adding up to the width of the mode can
6638 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6639 && TREE_CODE (arg0
) == RROTATE_EXPR
6640 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6641 && TREE_INT_CST_HIGH (arg1
) == 0
6642 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6643 && ((TREE_INT_CST_LOW (arg1
)
6644 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6645 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6646 return TREE_OPERAND (arg0
, 0);
6651 if (operand_equal_p (arg0
, arg1
, 0))
6652 return omit_one_operand (type
, arg0
, arg1
);
6653 if (INTEGRAL_TYPE_P (type
)
6654 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6655 return omit_one_operand (type
, arg1
, arg0
);
6659 if (operand_equal_p (arg0
, arg1
, 0))
6660 return omit_one_operand (type
, arg0
, arg1
);
6661 if (INTEGRAL_TYPE_P (type
)
6662 && TYPE_MAX_VALUE (type
)
6663 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6664 return omit_one_operand (type
, arg1
, arg0
);
6667 case TRUTH_NOT_EXPR
:
6668 /* Note that the operand of this must be an int
6669 and its values must be 0 or 1.
6670 ("true" is a fixed value perhaps depending on the language,
6671 but we don't handle values other than 1 correctly yet.) */
6672 tem
= invert_truthvalue (arg0
);
6673 /* Avoid infinite recursion. */
6674 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6676 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
6681 return convert (type
, tem
);
6683 case TRUTH_ANDIF_EXPR
:
6684 /* Note that the operands of this must be ints
6685 and their values must be 0 or 1.
6686 ("true" is a fixed value perhaps depending on the language.) */
6687 /* If first arg is constant zero, return it. */
6688 if (integer_zerop (arg0
))
6689 return convert (type
, arg0
);
6690 case TRUTH_AND_EXPR
:
6691 /* If either arg is constant true, drop it. */
6692 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6693 return non_lvalue (convert (type
, arg1
));
6694 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6695 /* Preserve sequence points. */
6696 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6697 return non_lvalue (convert (type
, arg0
));
6698 /* If second arg is constant zero, result is zero, but first arg
6699 must be evaluated. */
6700 if (integer_zerop (arg1
))
6701 return omit_one_operand (type
, arg1
, arg0
);
6702 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6703 case will be handled here. */
6704 if (integer_zerop (arg0
))
6705 return omit_one_operand (type
, arg0
, arg1
);
6708 /* We only do these simplifications if we are optimizing. */
6712 /* Check for things like (A || B) && (A || C). We can convert this
6713 to A || (B && C). Note that either operator can be any of the four
6714 truth and/or operations and the transformation will still be
6715 valid. Also note that we only care about order for the
6716 ANDIF and ORIF operators. If B contains side effects, this
6717 might change the truth-value of A. */
6718 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6719 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6720 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6721 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6722 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6723 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6725 tree a00
= TREE_OPERAND (arg0
, 0);
6726 tree a01
= TREE_OPERAND (arg0
, 1);
6727 tree a10
= TREE_OPERAND (arg1
, 0);
6728 tree a11
= TREE_OPERAND (arg1
, 1);
6729 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6730 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6731 && (code
== TRUTH_AND_EXPR
6732 || code
== TRUTH_OR_EXPR
));
6734 if (operand_equal_p (a00
, a10
, 0))
6735 return fold (build (TREE_CODE (arg0
), type
, a00
,
6736 fold (build (code
, type
, a01
, a11
))));
6737 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6738 return fold (build (TREE_CODE (arg0
), type
, a00
,
6739 fold (build (code
, type
, a01
, a10
))));
6740 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6741 return fold (build (TREE_CODE (arg0
), type
, a01
,
6742 fold (build (code
, type
, a00
, a11
))));
6744 /* This case if tricky because we must either have commutative
6745 operators or else A10 must not have side-effects. */
6747 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6748 && operand_equal_p (a01
, a11
, 0))
6749 return fold (build (TREE_CODE (arg0
), type
,
6750 fold (build (code
, type
, a00
, a10
)),
6754 /* See if we can build a range comparison. */
6755 if (0 != (tem
= fold_range_test (t
)))
6758 /* Check for the possibility of merging component references. If our
6759 lhs is another similar operation, try to merge its rhs with our
6760 rhs. Then try to merge our lhs and rhs. */
6761 if (TREE_CODE (arg0
) == code
6762 && 0 != (tem
= fold_truthop (code
, type
,
6763 TREE_OPERAND (arg0
, 1), arg1
)))
6764 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6766 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6771 case TRUTH_ORIF_EXPR
:
6772 /* Note that the operands of this must be ints
6773 and their values must be 0 or true.
6774 ("true" is a fixed value perhaps depending on the language.) */
6775 /* If first arg is constant true, return it. */
6776 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6777 return convert (type
, arg0
);
6779 /* If either arg is constant zero, drop it. */
6780 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6781 return non_lvalue (convert (type
, arg1
));
6782 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6783 /* Preserve sequence points. */
6784 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6785 return non_lvalue (convert (type
, arg0
));
6786 /* If second arg is constant true, result is true, but we must
6787 evaluate first arg. */
6788 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6789 return omit_one_operand (type
, arg1
, arg0
);
6790 /* Likewise for first arg, but note this only occurs here for
6792 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6793 return omit_one_operand (type
, arg0
, arg1
);
6796 case TRUTH_XOR_EXPR
:
6797 /* If either arg is constant zero, drop it. */
6798 if (integer_zerop (arg0
))
6799 return non_lvalue (convert (type
, arg1
));
6800 if (integer_zerop (arg1
))
6801 return non_lvalue (convert (type
, arg0
));
6802 /* If either arg is constant true, this is a logical inversion. */
6803 if (integer_onep (arg0
))
6804 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6805 if (integer_onep (arg1
))
6806 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6815 /* If one arg is a real or integer constant, put it last. */
6816 if ((TREE_CODE (arg0
) == INTEGER_CST
6817 && TREE_CODE (arg1
) != INTEGER_CST
)
6818 || (TREE_CODE (arg0
) == REAL_CST
6819 && TREE_CODE (arg0
) != REAL_CST
))
6823 TREE_OPERAND (t
, 0) = arg1
;
6824 TREE_OPERAND (t
, 1) = arg0
;
6825 arg0
= TREE_OPERAND (t
, 0);
6826 arg1
= TREE_OPERAND (t
, 1);
6827 code
= swap_tree_comparison (code
);
6828 TREE_SET_CODE (t
, code
);
6831 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6833 tree targ0
= strip_float_extensions (arg0
);
6834 tree targ1
= strip_float_extensions (arg1
);
6835 tree newtype
= TREE_TYPE (targ0
);
6837 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
6838 newtype
= TREE_TYPE (targ1
);
6840 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6841 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
6842 return fold (build (code
, type
, convert (newtype
, targ0
),
6843 convert (newtype
, targ1
)));
6845 /* (-a) CMP (-b) -> b CMP a */
6846 if (TREE_CODE (arg0
) == NEGATE_EXPR
6847 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6848 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6849 TREE_OPERAND (arg0
, 0)));
6851 if (TREE_CODE (arg1
) == REAL_CST
)
6853 REAL_VALUE_TYPE cst
;
6854 cst
= TREE_REAL_CST (arg1
);
6856 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6857 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
6859 fold (build (swap_tree_comparison (code
), type
,
6860 TREE_OPERAND (arg0
, 0),
6861 build_real (TREE_TYPE (arg1
),
6862 REAL_VALUE_NEGATE (cst
))));
6864 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6865 /* a CMP (-0) -> a CMP 0 */
6866 if (REAL_VALUE_MINUS_ZERO (cst
))
6867 return fold (build (code
, type
, arg0
,
6868 build_real (TREE_TYPE (arg1
), dconst0
)));
6870 /* x != NaN is always true, other ops are always false. */
6871 if (REAL_VALUE_ISNAN (cst
)
6872 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
6874 t
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
6875 return omit_one_operand (type
, convert (type
, t
), arg0
);
6878 /* Fold comparisons against infinity. */
6879 if (REAL_VALUE_ISINF (cst
))
6881 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
6882 if (tem
!= NULL_TREE
)
6887 /* If this is a comparison of a real constant with a PLUS_EXPR
6888 or a MINUS_EXPR of a real constant, we can convert it into a
6889 comparison with a revised real constant as long as no overflow
6890 occurs when unsafe_math_optimizations are enabled. */
6891 if (flag_unsafe_math_optimizations
6892 && TREE_CODE (arg1
) == REAL_CST
6893 && (TREE_CODE (arg0
) == PLUS_EXPR
6894 || TREE_CODE (arg0
) == MINUS_EXPR
)
6895 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6896 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6897 ? MINUS_EXPR
: PLUS_EXPR
,
6898 arg1
, TREE_OPERAND (arg0
, 1), 0))
6899 && ! TREE_CONSTANT_OVERFLOW (tem
))
6900 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6902 /* Likewise, we can simplify a comparison of a real constant with
6903 a MINUS_EXPR whose first operand is also a real constant, i.e.
6904 (c1 - x) < c2 becomes x > c1-c2. */
6905 if (flag_unsafe_math_optimizations
6906 && TREE_CODE (arg1
) == REAL_CST
6907 && TREE_CODE (arg0
) == MINUS_EXPR
6908 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
6909 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
6911 && ! TREE_CONSTANT_OVERFLOW (tem
))
6912 return fold (build (swap_tree_comparison (code
), type
,
6913 TREE_OPERAND (arg0
, 1), tem
));
6915 /* Fold comparisons against built-in math functions. */
6916 if (TREE_CODE (arg1
) == REAL_CST
6917 && flag_unsafe_math_optimizations
6918 && ! flag_errno_math
)
6920 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
6922 if (fcode
!= END_BUILTINS
)
6924 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
6925 if (tem
!= NULL_TREE
)
6931 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6932 First, see if one arg is constant; find the constant arg
6933 and the other one. */
6935 tree constop
= 0, varop
= NULL_TREE
;
6936 int constopnum
= -1;
6938 if (TREE_CONSTANT (arg1
))
6939 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6940 if (TREE_CONSTANT (arg0
))
6941 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6943 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6945 /* This optimization is invalid for ordered comparisons
6946 if CONST+INCR overflows or if foo+incr might overflow.
6947 This optimization is invalid for floating point due to rounding.
6948 For pointer types we assume overflow doesn't happen. */
6949 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6950 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6951 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6954 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6955 constop
, TREE_OPERAND (varop
, 1)));
6957 /* Do not overwrite the current varop to be a preincrement,
6958 create a new node so that we won't confuse our caller who
6959 might create trees and throw them away, reusing the
6960 arguments that they passed to build. This shows up in
6961 the THEN or ELSE parts of ?: being postincrements. */
6962 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6963 TREE_OPERAND (varop
, 0),
6964 TREE_OPERAND (varop
, 1));
6966 /* If VAROP is a reference to a bitfield, we must mask
6967 the constant by the width of the field. */
6968 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6969 && DECL_BIT_FIELD(TREE_OPERAND
6970 (TREE_OPERAND (varop
, 0), 1)))
6973 = TREE_INT_CST_LOW (DECL_SIZE
6975 (TREE_OPERAND (varop
, 0), 1)));
6976 tree mask
, unsigned_type
;
6977 unsigned int precision
;
6978 tree folded_compare
;
6980 /* First check whether the comparison would come out
6981 always the same. If we don't do that we would
6982 change the meaning with the masking. */
6983 if (constopnum
== 0)
6984 folded_compare
= fold (build (code
, type
, constop
,
6985 TREE_OPERAND (varop
, 0)));
6987 folded_compare
= fold (build (code
, type
,
6988 TREE_OPERAND (varop
, 0),
6990 if (integer_zerop (folded_compare
)
6991 || integer_onep (folded_compare
))
6992 return omit_one_operand (type
, folded_compare
, varop
);
6994 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6995 precision
= TYPE_PRECISION (unsigned_type
);
6996 mask
= build_int_2 (~0, ~0);
6997 TREE_TYPE (mask
) = unsigned_type
;
6998 force_fit_type (mask
, 0);
6999 mask
= const_binop (RSHIFT_EXPR
, mask
,
7000 size_int (precision
- size
), 0);
7001 newconst
= fold (build (BIT_AND_EXPR
,
7002 TREE_TYPE (varop
), newconst
,
7003 convert (TREE_TYPE (varop
),
7007 t
= build (code
, type
,
7008 (constopnum
== 0) ? newconst
: varop
,
7009 (constopnum
== 1) ? newconst
: varop
);
7013 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
7015 if (POINTER_TYPE_P (TREE_TYPE (varop
))
7016 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
7017 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
7020 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
7021 constop
, TREE_OPERAND (varop
, 1)));
7023 /* Do not overwrite the current varop to be a predecrement,
7024 create a new node so that we won't confuse our caller who
7025 might create trees and throw them away, reusing the
7026 arguments that they passed to build. This shows up in
7027 the THEN or ELSE parts of ?: being postdecrements. */
7028 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
7029 TREE_OPERAND (varop
, 0),
7030 TREE_OPERAND (varop
, 1));
7032 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
7033 && DECL_BIT_FIELD(TREE_OPERAND
7034 (TREE_OPERAND (varop
, 0), 1)))
7037 = TREE_INT_CST_LOW (DECL_SIZE
7039 (TREE_OPERAND (varop
, 0), 1)));
7040 tree mask
, unsigned_type
;
7041 unsigned int precision
;
7042 tree folded_compare
;
7044 if (constopnum
== 0)
7045 folded_compare
= fold (build (code
, type
, constop
,
7046 TREE_OPERAND (varop
, 0)));
7048 folded_compare
= fold (build (code
, type
,
7049 TREE_OPERAND (varop
, 0),
7051 if (integer_zerop (folded_compare
)
7052 || integer_onep (folded_compare
))
7053 return omit_one_operand (type
, folded_compare
, varop
);
7055 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
7056 precision
= TYPE_PRECISION (unsigned_type
);
7057 mask
= build_int_2 (~0, ~0);
7058 TREE_TYPE (mask
) = TREE_TYPE (varop
);
7059 force_fit_type (mask
, 0);
7060 mask
= const_binop (RSHIFT_EXPR
, mask
,
7061 size_int (precision
- size
), 0);
7062 newconst
= fold (build (BIT_AND_EXPR
,
7063 TREE_TYPE (varop
), newconst
,
7064 convert (TREE_TYPE (varop
),
7068 t
= build (code
, type
,
7069 (constopnum
== 0) ? newconst
: varop
,
7070 (constopnum
== 1) ? newconst
: varop
);
7076 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
7077 This transformation affects the cases which are handled in later
7078 optimizations involving comparisons with non-negative constants. */
7079 if (TREE_CODE (arg1
) == INTEGER_CST
7080 && TREE_CODE (arg0
) != INTEGER_CST
7081 && tree_int_cst_sgn (arg1
) > 0)
7087 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7088 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7093 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7094 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7102 /* Comparisons with the highest or lowest possible integer of
7103 the specified size will have known values. */
7105 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
7107 if (TREE_CODE (arg1
) == INTEGER_CST
7108 && ! TREE_CONSTANT_OVERFLOW (arg1
)
7109 && width
<= HOST_BITS_PER_WIDE_INT
7110 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
7111 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
7113 unsigned HOST_WIDE_INT signed_max
;
7114 unsigned HOST_WIDE_INT max
, min
;
7116 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
7118 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7120 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
7126 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
7129 if (TREE_INT_CST_HIGH (arg1
) == 0
7130 && TREE_INT_CST_LOW (arg1
) == max
)
7134 return omit_one_operand (type
,
7135 convert (type
, integer_zero_node
),
7141 TREE_SET_CODE (t
, EQ_EXPR
);
7144 return omit_one_operand (type
,
7145 convert (type
, integer_one_node
),
7151 TREE_SET_CODE (t
, NE_EXPR
);
7154 /* The GE_EXPR and LT_EXPR cases above are not normally
7155 reached because of previous transformations. */
7160 else if (TREE_INT_CST_HIGH (arg1
) == 0
7161 && TREE_INT_CST_LOW (arg1
) == max
- 1)
7166 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
7167 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7171 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
7172 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7177 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
7178 && TREE_INT_CST_LOW (arg1
) == min
)
7182 return omit_one_operand (type
,
7183 convert (type
, integer_zero_node
),
7189 TREE_SET_CODE (t
, EQ_EXPR
);
7193 return omit_one_operand (type
,
7194 convert (type
, integer_one_node
),
7200 TREE_SET_CODE (t
, NE_EXPR
);
7206 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
7207 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
7212 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7213 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7217 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
7218 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
7224 else if (TREE_INT_CST_HIGH (arg1
) == 0
7225 && TREE_INT_CST_LOW (arg1
) == signed_max
7226 && TREE_UNSIGNED (TREE_TYPE (arg1
))
7227 /* signed_type does not work on pointer types. */
7228 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
7230 /* The following case also applies to X < signed_max+1
7231 and X >= signed_max+1 because previous transformations. */
7232 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7235 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
7236 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
7238 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
7239 type
, convert (st0
, arg0
),
7240 convert (st1
, integer_zero_node
)));
7246 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
7247 a MINUS_EXPR of a constant, we can convert it into a comparison with
7248 a revised constant as long as no overflow occurs. */
7249 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7250 && TREE_CODE (arg1
) == INTEGER_CST
7251 && (TREE_CODE (arg0
) == PLUS_EXPR
7252 || TREE_CODE (arg0
) == MINUS_EXPR
)
7253 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7254 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
7255 ? MINUS_EXPR
: PLUS_EXPR
,
7256 arg1
, TREE_OPERAND (arg0
, 1), 0))
7257 && ! TREE_CONSTANT_OVERFLOW (tem
))
7258 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7260 /* Similarly for a NEGATE_EXPR. */
7261 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7262 && TREE_CODE (arg0
) == NEGATE_EXPR
7263 && TREE_CODE (arg1
) == INTEGER_CST
7264 && 0 != (tem
= negate_expr (arg1
))
7265 && TREE_CODE (tem
) == INTEGER_CST
7266 && ! TREE_CONSTANT_OVERFLOW (tem
))
7267 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
7269 /* If we have X - Y == 0, we can convert that to X == Y and similarly
7270 for !=. Don't do this for ordered comparisons due to overflow. */
7271 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7272 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
7273 return fold (build (code
, type
,
7274 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
7276 /* If we are widening one operand of an integer comparison,
7277 see if the other operand is similarly being widened. Perhaps we
7278 can do the comparison in the narrower type. */
7279 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
7280 && TREE_CODE (arg0
) == NOP_EXPR
7281 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
7282 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
7283 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
7284 || (TREE_CODE (t1
) == INTEGER_CST
7285 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
7286 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
7288 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
7289 constant, we can simplify it. */
7290 else if (TREE_CODE (arg1
) == INTEGER_CST
7291 && (TREE_CODE (arg0
) == MIN_EXPR
7292 || TREE_CODE (arg0
) == MAX_EXPR
)
7293 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7294 return optimize_minmax_comparison (t
);
7296 /* If we are comparing an ABS_EXPR with a constant, we can
7297 convert all the cases into explicit comparisons, but they may
7298 well not be faster than doing the ABS and one comparison.
7299 But ABS (X) <= C is a range comparison, which becomes a subtraction
7300 and a comparison, and is probably faster. */
7301 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
7302 && TREE_CODE (arg0
) == ABS_EXPR
7303 && ! TREE_SIDE_EFFECTS (arg0
)
7304 && (0 != (tem
= negate_expr (arg1
)))
7305 && TREE_CODE (tem
) == INTEGER_CST
7306 && ! TREE_CONSTANT_OVERFLOW (tem
))
7307 return fold (build (TRUTH_ANDIF_EXPR
, type
,
7308 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
7309 build (LE_EXPR
, type
,
7310 TREE_OPERAND (arg0
, 0), arg1
)));
7312 /* If this is an EQ or NE comparison with zero and ARG0 is
7313 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
7314 two operations, but the latter can be done in one less insn
7315 on machines that have only two-operand insns or on which a
7316 constant cannot be the first operand. */
7317 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7318 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
7320 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
7321 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
7323 fold (build (code
, type
,
7324 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7326 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
7327 TREE_OPERAND (arg0
, 1),
7328 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
7329 convert (TREE_TYPE (arg0
),
7332 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
7333 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
7335 fold (build (code
, type
,
7336 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
7338 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
7339 TREE_OPERAND (arg0
, 0),
7340 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
7341 convert (TREE_TYPE (arg0
),
7346 /* If this is an NE or EQ comparison of zero against the result of a
7347 signed MOD operation whose second operand is a power of 2, make
7348 the MOD operation unsigned since it is simpler and equivalent. */
7349 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
7350 && integer_zerop (arg1
)
7351 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
7352 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
7353 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
7354 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
7355 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
7356 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
7358 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
7359 tree newmod
= build (TREE_CODE (arg0
), newtype
,
7360 convert (newtype
, TREE_OPERAND (arg0
, 0)),
7361 convert (newtype
, TREE_OPERAND (arg0
, 1)));
7363 return build (code
, type
, newmod
, convert (newtype
, arg1
));
7366 /* If this is an NE comparison of zero with an AND of one, remove the
7367 comparison since the AND will give the correct value. */
7368 if (code
== NE_EXPR
&& integer_zerop (arg1
)
7369 && TREE_CODE (arg0
) == BIT_AND_EXPR
7370 && integer_onep (TREE_OPERAND (arg0
, 1)))
7371 return convert (type
, arg0
);
7373 /* If we have (A & C) == C where C is a power of 2, convert this into
7374 (A & C) != 0. Similarly for NE_EXPR. */
7375 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7376 && TREE_CODE (arg0
) == BIT_AND_EXPR
7377 && integer_pow2p (TREE_OPERAND (arg0
, 1))
7378 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
7379 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
7380 arg0
, integer_zero_node
));
7382 /* If we have (A & C) != 0 or (A & C) == 0 and C is a power of
7383 2, then fold the expression into shifts and logical operations. */
7384 tem
= fold_single_bit_test (code
, arg0
, arg1
, type
);
7388 /* If we have (A & C) == D where D & ~C != 0, convert this into 0.
7389 Similarly for NE_EXPR. */
7390 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7391 && TREE_CODE (arg0
) == BIT_AND_EXPR
7392 && TREE_CODE (arg1
) == INTEGER_CST
7393 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7395 tree dandnotc
= fold (build (BIT_ANDTC_EXPR
, TREE_TYPE (arg0
),
7396 arg1
, TREE_OPERAND (arg0
, 1)));
7397 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
7398 if (!integer_zerop (dandnotc
))
7399 return omit_one_operand (type
, rslt
, arg0
);
7402 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
7403 Similarly for NE_EXPR. */
7404 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7405 && TREE_CODE (arg0
) == BIT_IOR_EXPR
7406 && TREE_CODE (arg1
) == INTEGER_CST
7407 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
7409 tree candnotd
= fold (build (BIT_ANDTC_EXPR
, TREE_TYPE (arg0
),
7410 TREE_OPERAND (arg0
, 1), arg1
));
7411 tree rslt
= code
== EQ_EXPR
? integer_zero_node
: integer_one_node
;
7412 if (!integer_zerop (candnotd
))
7413 return omit_one_operand (type
, rslt
, arg0
);
7416 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7417 and similarly for >= into !=. */
7418 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7419 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7420 && TREE_CODE (arg1
) == LSHIFT_EXPR
7421 && integer_onep (TREE_OPERAND (arg1
, 0)))
7422 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7423 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7424 TREE_OPERAND (arg1
, 1)),
7425 convert (TREE_TYPE (arg0
), integer_zero_node
));
7427 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7428 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7429 && (TREE_CODE (arg1
) == NOP_EXPR
7430 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7431 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
7432 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
7434 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7435 convert (TREE_TYPE (arg0
),
7436 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7437 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
7438 convert (TREE_TYPE (arg0
), integer_zero_node
));
7440 /* Simplify comparison of something with itself. (For IEEE
7441 floating-point, we can only do some of these simplifications.) */
7442 if (operand_equal_p (arg0
, arg1
, 0))
7449 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
))
7450 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7451 return constant_boolean_node (1, type
);
7455 TREE_SET_CODE (t
, code
);
7459 /* For NE, we can only do this simplification if integer
7460 or we don't honor IEEE floating point NaNs. */
7461 if (FLOAT_TYPE_P (TREE_TYPE (arg0
))
7462 && HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
))))
7464 /* ... fall through ... */
7467 return constant_boolean_node (0, type
);
7473 /* If we are comparing an expression that just has comparisons
7474 of two integer values, arithmetic expressions of those comparisons,
7475 and constants, we can simplify it. There are only three cases
7476 to check: the two values can either be equal, the first can be
7477 greater, or the second can be greater. Fold the expression for
7478 those three values. Since each value must be 0 or 1, we have
7479 eight possibilities, each of which corresponds to the constant 0
7480 or 1 or one of the six possible comparisons.
7482 This handles common cases like (a > b) == 0 but also handles
7483 expressions like ((x > y) - (y > x)) > 0, which supposedly
7484 occur in macroized code. */
7486 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
7488 tree cval1
= 0, cval2
= 0;
7491 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
7492 /* Don't handle degenerate cases here; they should already
7493 have been handled anyway. */
7494 && cval1
!= 0 && cval2
!= 0
7495 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
7496 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
7497 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
7498 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
7499 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
7500 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
7501 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
7503 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
7504 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
7506 /* We can't just pass T to eval_subst in case cval1 or cval2
7507 was the same as ARG1. */
7510 = fold (build (code
, type
,
7511 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
7514 = fold (build (code
, type
,
7515 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
7518 = fold (build (code
, type
,
7519 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
7522 /* All three of these results should be 0 or 1. Confirm they
7523 are. Then use those values to select the proper code
7526 if ((integer_zerop (high_result
)
7527 || integer_onep (high_result
))
7528 && (integer_zerop (equal_result
)
7529 || integer_onep (equal_result
))
7530 && (integer_zerop (low_result
)
7531 || integer_onep (low_result
)))
7533 /* Make a 3-bit mask with the high-order bit being the
7534 value for `>', the next for '=', and the low for '<'. */
7535 switch ((integer_onep (high_result
) * 4)
7536 + (integer_onep (equal_result
) * 2)
7537 + integer_onep (low_result
))
7541 return omit_one_operand (type
, integer_zero_node
, arg0
);
7562 return omit_one_operand (type
, integer_one_node
, arg0
);
7565 t
= build (code
, type
, cval1
, cval2
);
7567 return save_expr (t
);
7574 /* If this is a comparison of a field, we may be able to simplify it. */
7575 if (((TREE_CODE (arg0
) == COMPONENT_REF
7576 && (*lang_hooks
.can_use_bit_fields_p
) ())
7577 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
7578 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7579 /* Handle the constant case even without -O
7580 to make sure the warnings are given. */
7581 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
7583 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
7587 /* If this is a comparison of complex values and either or both sides
7588 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7589 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7590 This may prevent needless evaluations. */
7591 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7592 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
7593 && (TREE_CODE (arg0
) == COMPLEX_EXPR
7594 || TREE_CODE (arg1
) == COMPLEX_EXPR
7595 || TREE_CODE (arg0
) == COMPLEX_CST
7596 || TREE_CODE (arg1
) == COMPLEX_CST
))
7598 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
7599 tree real0
, imag0
, real1
, imag1
;
7601 arg0
= save_expr (arg0
);
7602 arg1
= save_expr (arg1
);
7603 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
7604 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
7605 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
7606 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
7608 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
7611 fold (build (code
, type
, real0
, real1
)),
7612 fold (build (code
, type
, imag0
, imag1
))));
7615 /* Optimize comparisons of strlen vs zero to a compare of the
7616 first character of the string vs zero. To wit,
7617 strlen(ptr) == 0 => *ptr == 0
7618 strlen(ptr) != 0 => *ptr != 0
7619 Other cases should reduce to one of these two (or a constant)
7620 due to the return value of strlen being unsigned. */
7621 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7622 && integer_zerop (arg1
)
7623 && TREE_CODE (arg0
) == CALL_EXPR
)
7625 tree fndecl
= get_callee_fndecl (arg0
);
7629 && DECL_BUILT_IN (fndecl
)
7630 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
7631 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
7632 && (arglist
= TREE_OPERAND (arg0
, 1))
7633 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
7634 && ! TREE_CHAIN (arglist
))
7635 return fold (build (code
, type
,
7636 build1 (INDIRECT_REF
, char_type_node
,
7637 TREE_VALUE(arglist
)),
7638 integer_zero_node
));
7641 /* From here on, the only cases we handle are when the result is
7642 known to be a constant.
7644 To compute GT, swap the arguments and do LT.
7645 To compute GE, do LT and invert the result.
7646 To compute LE, swap the arguments, do LT and invert the result.
7647 To compute NE, do EQ and invert the result.
7649 Therefore, the code below must handle only EQ and LT. */
7651 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7653 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
7654 code
= swap_tree_comparison (code
);
7657 /* Note that it is safe to invert for real values here because we
7658 will check below in the one case that it matters. */
7662 if (code
== NE_EXPR
|| code
== GE_EXPR
)
7665 code
= invert_tree_comparison (code
);
7668 /* Compute a result for LT or EQ if args permit;
7669 otherwise return T. */
7670 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
7672 if (code
== EQ_EXPR
)
7673 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
7675 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
7676 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
7677 : INT_CST_LT (arg0
, arg1
)),
7681 #if 0 /* This is no longer useful, but breaks some real code. */
7682 /* Assume a nonexplicit constant cannot equal an explicit one,
7683 since such code would be undefined anyway.
7684 Exception: on sysvr4, using #pragma weak,
7685 a label can come out as 0. */
7686 else if (TREE_CODE (arg1
) == INTEGER_CST
7687 && !integer_zerop (arg1
)
7688 && TREE_CONSTANT (arg0
)
7689 && TREE_CODE (arg0
) == ADDR_EXPR
7691 t1
= build_int_2 (0, 0);
7693 /* Two real constants can be compared explicitly. */
7694 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
7696 /* If either operand is a NaN, the result is false with two
7697 exceptions: First, an NE_EXPR is true on NaNs, but that case
7698 is already handled correctly since we will be inverting the
7699 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7700 or a GE_EXPR into a LT_EXPR, we must return true so that it
7701 will be inverted into false. */
7703 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
7704 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
7705 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
7707 else if (code
== EQ_EXPR
)
7708 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
7709 TREE_REAL_CST (arg1
)),
7712 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
7713 TREE_REAL_CST (arg1
)),
7717 if (t1
== NULL_TREE
)
7721 TREE_INT_CST_LOW (t1
) ^= 1;
7723 TREE_TYPE (t1
) = type
;
7724 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7725 return (*lang_hooks
.truthvalue_conversion
) (t1
);
7729 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7730 so all simple results must be passed through pedantic_non_lvalue. */
7731 if (TREE_CODE (arg0
) == INTEGER_CST
)
7732 return pedantic_non_lvalue
7733 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7734 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7735 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7737 /* If the second operand is zero, invert the comparison and swap
7738 the second and third operands. Likewise if the second operand
7739 is constant and the third is not or if the third operand is
7740 equivalent to the first operand of the comparison. */
7742 if (integer_zerop (arg1
)
7743 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7744 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7745 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7746 TREE_OPERAND (t
, 2),
7747 TREE_OPERAND (arg0
, 1))))
7749 /* See if this can be inverted. If it can't, possibly because
7750 it was a floating-point inequality comparison, don't do
7752 tem
= invert_truthvalue (arg0
);
7754 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7756 t
= build (code
, type
, tem
,
7757 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7759 /* arg1 should be the first argument of the new T. */
7760 arg1
= TREE_OPERAND (t
, 1);
7765 /* If we have A op B ? A : C, we may be able to convert this to a
7766 simpler expression, depending on the operation and the values
7767 of B and C. Signed zeros prevent all of these transformations,
7768 for reasons given above each one. */
7770 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7771 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7772 arg1
, TREE_OPERAND (arg0
, 1))
7773 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
7775 tree arg2
= TREE_OPERAND (t
, 2);
7776 enum tree_code comp_code
= TREE_CODE (arg0
);
7780 /* If we have A op 0 ? A : -A, consider applying the following
7783 A == 0? A : -A same as -A
7784 A != 0? A : -A same as A
7785 A >= 0? A : -A same as abs (A)
7786 A > 0? A : -A same as abs (A)
7787 A <= 0? A : -A same as -abs (A)
7788 A < 0? A : -A same as -abs (A)
7790 None of these transformations work for modes with signed
7791 zeros. If A is +/-0, the first two transformations will
7792 change the sign of the result (from +0 to -0, or vice
7793 versa). The last four will fix the sign of the result,
7794 even though the original expressions could be positive or
7795 negative, depending on the sign of A.
7797 Note that all these transformations are correct if A is
7798 NaN, since the two alternatives (A and -A) are also NaNs. */
7799 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7800 ? real_zerop (TREE_OPERAND (arg0
, 1))
7801 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7802 && TREE_CODE (arg2
) == NEGATE_EXPR
7803 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7811 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7814 return pedantic_non_lvalue (convert (type
, arg1
));
7817 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7818 arg1
= convert ((*lang_hooks
.types
.signed_type
)
7819 (TREE_TYPE (arg1
)), arg1
);
7820 return pedantic_non_lvalue
7821 (convert (type
, fold (build1 (ABS_EXPR
,
7822 TREE_TYPE (arg1
), arg1
))));
7825 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7826 arg1
= convert ((lang_hooks
.types
.signed_type
)
7827 (TREE_TYPE (arg1
)), arg1
);
7828 return pedantic_non_lvalue
7829 (negate_expr (convert (type
,
7830 fold (build1 (ABS_EXPR
,
7837 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7838 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7839 both transformations are correct when A is NaN: A != 0
7840 is then true, and A == 0 is false. */
7842 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7844 if (comp_code
== NE_EXPR
)
7845 return pedantic_non_lvalue (convert (type
, arg1
));
7846 else if (comp_code
== EQ_EXPR
)
7847 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7850 /* Try some transformations of A op B ? A : B.
7852 A == B? A : B same as B
7853 A != B? A : B same as A
7854 A >= B? A : B same as max (A, B)
7855 A > B? A : B same as max (B, A)
7856 A <= B? A : B same as min (A, B)
7857 A < B? A : B same as min (B, A)
7859 As above, these transformations don't work in the presence
7860 of signed zeros. For example, if A and B are zeros of
7861 opposite sign, the first two transformations will change
7862 the sign of the result. In the last four, the original
7863 expressions give different results for (A=+0, B=-0) and
7864 (A=-0, B=+0), but the transformed expressions do not.
7866 The first two transformations are correct if either A or B
7867 is a NaN. In the first transformation, the condition will
7868 be false, and B will indeed be chosen. In the case of the
7869 second transformation, the condition A != B will be true,
7870 and A will be chosen.
7872 The conversions to max() and min() are not correct if B is
7873 a number and A is not. The conditions in the original
7874 expressions will be false, so all four give B. The min()
7875 and max() versions would give a NaN instead. */
7876 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7877 arg2
, TREE_OPERAND (arg0
, 0)))
7879 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7880 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7881 tree comp_type
= TREE_TYPE (comp_op0
);
7883 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7884 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7894 return pedantic_non_lvalue (convert (type
, arg2
));
7896 return pedantic_non_lvalue (convert (type
, arg1
));
7899 /* In C++ a ?: expression can be an lvalue, so put the
7900 operand which will be used if they are equal first
7901 so that we can convert this back to the
7902 corresponding COND_EXPR. */
7903 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7904 return pedantic_non_lvalue
7905 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7906 (comp_code
== LE_EXPR
7907 ? comp_op0
: comp_op1
),
7908 (comp_code
== LE_EXPR
7909 ? comp_op1
: comp_op0
)))));
7913 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7914 return pedantic_non_lvalue
7915 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7916 (comp_code
== GE_EXPR
7917 ? comp_op0
: comp_op1
),
7918 (comp_code
== GE_EXPR
7919 ? comp_op1
: comp_op0
)))));
7926 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7927 we might still be able to simplify this. For example,
7928 if C1 is one less or one more than C2, this might have started
7929 out as a MIN or MAX and been transformed by this function.
7930 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7932 if (INTEGRAL_TYPE_P (type
)
7933 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7934 && TREE_CODE (arg2
) == INTEGER_CST
)
7938 /* We can replace A with C1 in this case. */
7939 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7940 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7941 TREE_OPERAND (t
, 2));
7945 /* If C1 is C2 + 1, this is min(A, C2). */
7946 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7947 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7948 const_binop (PLUS_EXPR
, arg2
,
7949 integer_one_node
, 0), 1))
7950 return pedantic_non_lvalue
7951 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7955 /* If C1 is C2 - 1, this is min(A, C2). */
7956 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7957 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7958 const_binop (MINUS_EXPR
, arg2
,
7959 integer_one_node
, 0), 1))
7960 return pedantic_non_lvalue
7961 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7965 /* If C1 is C2 - 1, this is max(A, C2). */
7966 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7967 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7968 const_binop (MINUS_EXPR
, arg2
,
7969 integer_one_node
, 0), 1))
7970 return pedantic_non_lvalue
7971 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7975 /* If C1 is C2 + 1, this is max(A, C2). */
7976 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7977 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7978 const_binop (PLUS_EXPR
, arg2
,
7979 integer_one_node
, 0), 1))
7980 return pedantic_non_lvalue
7981 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7990 /* If the second operand is simpler than the third, swap them
7991 since that produces better jump optimization results. */
7992 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7993 || TREE_CODE (arg1
) == SAVE_EXPR
)
7994 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7995 || DECL_P (TREE_OPERAND (t
, 2))
7996 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7998 /* See if this can be inverted. If it can't, possibly because
7999 it was a floating-point inequality comparison, don't do
8001 tem
= invert_truthvalue (arg0
);
8003 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
8005 t
= build (code
, type
, tem
,
8006 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
8008 /* arg1 should be the first argument of the new T. */
8009 arg1
= TREE_OPERAND (t
, 1);
8014 /* Convert A ? 1 : 0 to simply A. */
8015 if (integer_onep (TREE_OPERAND (t
, 1))
8016 && integer_zerop (TREE_OPERAND (t
, 2))
8017 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
8018 call to fold will try to move the conversion inside
8019 a COND, which will recurse. In that case, the COND_EXPR
8020 is probably the best choice, so leave it alone. */
8021 && type
== TREE_TYPE (arg0
))
8022 return pedantic_non_lvalue (arg0
);
8024 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
8025 over COND_EXPR in cases such as floating point comparisons. */
8026 if (integer_zerop (TREE_OPERAND (t
, 1))
8027 && integer_onep (TREE_OPERAND (t
, 2))
8028 && truth_value_p (TREE_CODE (arg0
)))
8029 return pedantic_non_lvalue (convert (type
,
8030 invert_truthvalue (arg0
)));
8032 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
8033 operation is simply A & 2. */
8035 if (integer_zerop (TREE_OPERAND (t
, 2))
8036 && TREE_CODE (arg0
) == NE_EXPR
8037 && integer_zerop (TREE_OPERAND (arg0
, 1))
8038 && integer_pow2p (arg1
)
8039 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
8040 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
8042 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
8044 /* Convert A ? B : 0 into A && B if A and B are truth values. */
8045 if (integer_zerop (TREE_OPERAND (t
, 2))
8046 && truth_value_p (TREE_CODE (arg0
))
8047 && truth_value_p (TREE_CODE (arg1
)))
8048 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
8051 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
8052 if (integer_onep (TREE_OPERAND (t
, 2))
8053 && truth_value_p (TREE_CODE (arg0
))
8054 && truth_value_p (TREE_CODE (arg1
)))
8056 /* Only perform transformation if ARG0 is easily inverted. */
8057 tem
= invert_truthvalue (arg0
);
8058 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
8059 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
8066 /* When pedantic, a compound expression can be neither an lvalue
8067 nor an integer constant expression. */
8068 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
8070 /* Don't let (0, 0) be null pointer constant. */
8071 if (integer_zerop (arg1
))
8072 return build1 (NOP_EXPR
, type
, arg1
);
8073 return convert (type
, arg1
);
8077 return build_complex (type
, arg0
, arg1
);
8081 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8083 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8084 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
8085 TREE_OPERAND (arg0
, 1));
8086 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
8087 return TREE_REALPART (arg0
);
8088 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8089 return fold (build (TREE_CODE (arg0
), type
,
8090 fold (build1 (REALPART_EXPR
, type
,
8091 TREE_OPERAND (arg0
, 0))),
8092 fold (build1 (REALPART_EXPR
,
8093 type
, TREE_OPERAND (arg0
, 1)))));
8097 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
8098 return convert (type
, integer_zero_node
);
8099 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
8100 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
8101 TREE_OPERAND (arg0
, 0));
8102 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
8103 return TREE_IMAGPART (arg0
);
8104 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
8105 return fold (build (TREE_CODE (arg0
), type
,
8106 fold (build1 (IMAGPART_EXPR
, type
,
8107 TREE_OPERAND (arg0
, 0))),
8108 fold (build1 (IMAGPART_EXPR
, type
,
8109 TREE_OPERAND (arg0
, 1)))));
8112 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
8114 case CLEANUP_POINT_EXPR
:
8115 if (! has_cleanups (arg0
))
8116 return TREE_OPERAND (t
, 0);
8119 enum tree_code code0
= TREE_CODE (arg0
);
8120 int kind0
= TREE_CODE_CLASS (code0
);
8121 tree arg00
= TREE_OPERAND (arg0
, 0);
8124 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
8125 return fold (build1 (code0
, type
,
8126 fold (build1 (CLEANUP_POINT_EXPR
,
8127 TREE_TYPE (arg00
), arg00
))));
8129 if (kind0
== '<' || kind0
== '2'
8130 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
8131 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
8132 || code0
== TRUTH_XOR_EXPR
)
8134 arg01
= TREE_OPERAND (arg0
, 1);
8136 if (TREE_CONSTANT (arg00
)
8137 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
8138 && ! has_cleanups (arg00
)))
8139 return fold (build (code0
, type
, arg00
,
8140 fold (build1 (CLEANUP_POINT_EXPR
,
8141 TREE_TYPE (arg01
), arg01
))));
8143 if (TREE_CONSTANT (arg01
))
8144 return fold (build (code0
, type
,
8145 fold (build1 (CLEANUP_POINT_EXPR
,
8146 TREE_TYPE (arg00
), arg00
)),
8154 /* Check for a built-in function. */
8155 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
8156 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
8158 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
8160 tree tmp
= fold_builtin (expr
);
8168 } /* switch (code) */
8171 #ifdef ENABLE_FOLD_CHECKING
8174 static void fold_checksum_tree (tree
, struct md5_ctx
*, htab_t
);
8175 static void fold_check_failed (tree
, tree
);
8176 void print_fold_checksum (tree
);
8178 /* When --enable-checking=fold, compute a digest of expr before
8179 and after actual fold call to see if fold did not accidentally
8180 change original expr. */
8187 unsigned char checksum_before
[16], checksum_after
[16];
8190 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
8191 md5_init_ctx (&ctx
);
8192 fold_checksum_tree (expr
, &ctx
, ht
);
8193 md5_finish_ctx (&ctx
, checksum_before
);
8196 ret
= fold_1 (expr
);
8198 md5_init_ctx (&ctx
);
8199 fold_checksum_tree (expr
, &ctx
, ht
);
8200 md5_finish_ctx (&ctx
, checksum_after
);
8203 if (memcmp (checksum_before
, checksum_after
, 16))
8204 fold_check_failed (expr
, ret
);
8210 print_fold_checksum (tree expr
)
8213 unsigned char checksum
[16], cnt
;
8216 ht
= htab_create (32, htab_hash_pointer
, htab_eq_pointer
, NULL
);
8217 md5_init_ctx (&ctx
);
8218 fold_checksum_tree (expr
, &ctx
, ht
);
8219 md5_finish_ctx (&ctx
, checksum
);
8221 for (cnt
= 0; cnt
< 16; ++cnt
)
8222 fprintf (stderr
, "%02x", checksum
[cnt
]);
8223 putc ('\n', stderr
);
8227 fold_check_failed (tree expr ATTRIBUTE_UNUSED
, tree ret ATTRIBUTE_UNUSED
)
8229 internal_error ("fold check: original tree changed by fold");
8233 fold_checksum_tree (tree expr
, struct md5_ctx
*ctx
, htab_t ht
)
8236 enum tree_code code
;
8237 char buf
[sizeof (struct tree_decl
)];
8240 if (sizeof (struct tree_exp
) + 5 * sizeof (tree
)
8241 > sizeof (struct tree_decl
)
8242 || sizeof (struct tree_type
) > sizeof (struct tree_decl
))
8246 slot
= htab_find_slot (ht
, expr
, INSERT
);
8250 code
= TREE_CODE (expr
);
8251 if (code
== SAVE_EXPR
&& SAVE_EXPR_NOPLACEHOLDER (expr
))
8253 /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
8254 memcpy (buf
, expr
, tree_size (expr
));
8256 SAVE_EXPR_NOPLACEHOLDER (expr
) = 0;
8258 else if (TREE_CODE_CLASS (code
) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr
))
8260 /* Allow DECL_ASSEMBLER_NAME to be modified. */
8261 memcpy (buf
, expr
, tree_size (expr
));
8263 SET_DECL_ASSEMBLER_NAME (expr
, NULL
);
8265 else if (TREE_CODE_CLASS (code
) == 't'
8266 && (TYPE_POINTER_TO (expr
) || TYPE_REFERENCE_TO (expr
)))
8268 /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
8269 memcpy (buf
, expr
, tree_size (expr
));
8271 TYPE_POINTER_TO (expr
) = NULL
;
8272 TYPE_REFERENCE_TO (expr
) = NULL
;
8274 md5_process_bytes (expr
, tree_size (expr
), ctx
);
8275 fold_checksum_tree (TREE_TYPE (expr
), ctx
, ht
);
8276 if (TREE_CODE_CLASS (code
) != 't' && TREE_CODE_CLASS (code
) != 'd')
8277 fold_checksum_tree (TREE_CHAIN (expr
), ctx
, ht
);
8278 len
= TREE_CODE_LENGTH (code
);
8279 switch (TREE_CODE_CLASS (code
))
8285 md5_process_bytes (TREE_STRING_POINTER (expr
),
8286 TREE_STRING_LENGTH (expr
), ctx
);
8289 fold_checksum_tree (TREE_REALPART (expr
), ctx
, ht
);
8290 fold_checksum_tree (TREE_IMAGPART (expr
), ctx
, ht
);
8293 fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr
), ctx
, ht
);
8303 fold_checksum_tree (TREE_PURPOSE (expr
), ctx
, ht
);
8304 fold_checksum_tree (TREE_VALUE (expr
), ctx
, ht
);
8307 for (i
= 0; i
< TREE_VEC_LENGTH (expr
); ++i
)
8308 fold_checksum_tree (TREE_VEC_ELT (expr
, i
), ctx
, ht
);
8317 case SAVE_EXPR
: len
= 2; break;
8318 case GOTO_SUBROUTINE_EXPR
: len
= 0; break;
8319 case RTL_EXPR
: len
= 0; break;
8320 case WITH_CLEANUP_EXPR
: len
= 2; break;
8329 for (i
= 0; i
< len
; ++i
)
8330 fold_checksum_tree (TREE_OPERAND (expr
, i
), ctx
, ht
);
8333 fold_checksum_tree (DECL_SIZE (expr
), ctx
, ht
);
8334 fold_checksum_tree (DECL_SIZE_UNIT (expr
), ctx
, ht
);
8335 fold_checksum_tree (DECL_NAME (expr
), ctx
, ht
);
8336 fold_checksum_tree (DECL_CONTEXT (expr
), ctx
, ht
);
8337 fold_checksum_tree (DECL_ARGUMENTS (expr
), ctx
, ht
);
8338 fold_checksum_tree (DECL_RESULT_FLD (expr
), ctx
, ht
);
8339 fold_checksum_tree (DECL_INITIAL (expr
), ctx
, ht
);
8340 fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr
), ctx
, ht
);
8341 fold_checksum_tree (DECL_SECTION_NAME (expr
), ctx
, ht
);
8342 fold_checksum_tree (DECL_ATTRIBUTES (expr
), ctx
, ht
);
8343 fold_checksum_tree (DECL_VINDEX (expr
), ctx
, ht
);
8346 fold_checksum_tree (TYPE_VALUES (expr
), ctx
, ht
);
8347 fold_checksum_tree (TYPE_SIZE (expr
), ctx
, ht
);
8348 fold_checksum_tree (TYPE_SIZE_UNIT (expr
), ctx
, ht
);
8349 fold_checksum_tree (TYPE_ATTRIBUTES (expr
), ctx
, ht
);
8350 fold_checksum_tree (TYPE_NAME (expr
), ctx
, ht
);
8351 fold_checksum_tree (TYPE_MIN_VALUE (expr
), ctx
, ht
);
8352 fold_checksum_tree (TYPE_MAX_VALUE (expr
), ctx
, ht
);
8353 fold_checksum_tree (TYPE_MAIN_VARIANT (expr
), ctx
, ht
);
8354 fold_checksum_tree (TYPE_BINFO (expr
), ctx
, ht
);
8355 fold_checksum_tree (TYPE_CONTEXT (expr
), ctx
, ht
);
8364 /* Perform constant folding and related simplification of initializer
8365 expression EXPR. This behaves identically to "fold" but ignores
8366 potential run-time traps and exceptions that fold must preserve. */
8369 fold_initializer (tree expr
)
8371 int saved_signaling_nans
= flag_signaling_nans
;
8372 int saved_trapping_math
= flag_trapping_math
;
8373 int saved_trapv
= flag_trapv
;
8376 flag_signaling_nans
= 0;
8377 flag_trapping_math
= 0;
8380 result
= fold (expr
);
8382 flag_signaling_nans
= saved_signaling_nans
;
8383 flag_trapping_math
= saved_trapping_math
;
8384 flag_trapv
= saved_trapv
;
8389 /* Determine if first argument is a multiple of second argument. Return 0 if
8390 it is not, or we cannot easily determined it to be.
8392 An example of the sort of thing we care about (at this point; this routine
8393 could surely be made more general, and expanded to do what the *_DIV_EXPR's
8394 fold cases do now) is discovering that
8396 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8402 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
8404 This code also handles discovering that
8406 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
8408 is a multiple of 8 so we don't have to worry about dealing with a
8411 Note that we *look* inside a SAVE_EXPR only to determine how it was
8412 calculated; it is not safe for fold to do much of anything else with the
8413 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
8414 at run time. For example, the latter example above *cannot* be implemented
8415 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
8416 evaluation time of the original SAVE_EXPR is not necessarily the same at
8417 the time the new expression is evaluated. The only optimization of this
8418 sort that would be valid is changing
8420 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
8424 SAVE_EXPR (I) * SAVE_EXPR (J)
8426 (where the same SAVE_EXPR (J) is used in the original and the
8427 transformed version). */
8430 multiple_of_p (tree type
, tree top
, tree bottom
)
8432 if (operand_equal_p (top
, bottom
, 0))
8435 if (TREE_CODE (type
) != INTEGER_TYPE
)
8438 switch (TREE_CODE (top
))
8441 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
8442 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
8446 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
8447 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
8450 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
8454 op1
= TREE_OPERAND (top
, 1);
8455 /* const_binop may not detect overflow correctly,
8456 so check for it explicitly here. */
8457 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
8458 > TREE_INT_CST_LOW (op1
)
8459 && TREE_INT_CST_HIGH (op1
) == 0
8460 && 0 != (t1
= convert (type
,
8461 const_binop (LSHIFT_EXPR
, size_one_node
,
8463 && ! TREE_OVERFLOW (t1
))
8464 return multiple_of_p (type
, t1
, bottom
);
8469 /* Can't handle conversions from non-integral or wider integral type. */
8470 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
8471 || (TYPE_PRECISION (type
)
8472 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
8475 /* .. fall through ... */
8478 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
8481 if (TREE_CODE (bottom
) != INTEGER_CST
8482 || (TREE_UNSIGNED (type
)
8483 && (tree_int_cst_sgn (top
) < 0
8484 || tree_int_cst_sgn (bottom
) < 0)))
8486 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
8494 /* Return true if `t' is known to be non-negative. */
8497 tree_expr_nonnegative_p (tree t
)
8499 switch (TREE_CODE (t
))
8509 /* These are undefined at zero. This is true even if
8510 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
8511 computing here is a user-visible property. */
8515 return tree_int_cst_sgn (t
) >= 0;
8518 return ! REAL_VALUE_NEGATIVE (TREE_REAL_CST (t
));
8521 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8522 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8523 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8525 /* zero_extend(x) + zero_extend(y) is non-negative if x and y are
8526 both unsigned and at least 2 bits shorter than the result. */
8527 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8528 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8529 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8531 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8532 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8533 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8534 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8536 unsigned int prec
= MAX (TYPE_PRECISION (inner1
),
8537 TYPE_PRECISION (inner2
)) + 1;
8538 return prec
< TYPE_PRECISION (TREE_TYPE (t
));
8544 if (FLOAT_TYPE_P (TREE_TYPE (t
)))
8546 /* x * x for floating point x is always non-negative. */
8547 if (operand_equal_p (TREE_OPERAND (t
, 0), TREE_OPERAND (t
, 1), 0))
8549 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8550 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8553 /* zero_extend(x) * zero_extend(y) is non-negative if x and y are
8554 both unsigned and their total bits is shorter than the result. */
8555 if (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
8556 && TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
8557 && TREE_CODE (TREE_OPERAND (t
, 1)) == NOP_EXPR
)
8559 tree inner1
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
8560 tree inner2
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0));
8561 if (TREE_CODE (inner1
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner1
)
8562 && TREE_CODE (inner2
) == INTEGER_TYPE
&& TREE_UNSIGNED (inner2
))
8563 return TYPE_PRECISION (inner1
) + TYPE_PRECISION (inner2
)
8564 < TYPE_PRECISION (TREE_TYPE (t
));
8568 case TRUNC_DIV_EXPR
:
8570 case FLOOR_DIV_EXPR
:
8571 case ROUND_DIV_EXPR
:
8572 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8573 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8575 case TRUNC_MOD_EXPR
:
8577 case FLOOR_MOD_EXPR
:
8578 case ROUND_MOD_EXPR
:
8579 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8582 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8583 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8587 tree inner_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
8588 tree outer_type
= TREE_TYPE (t
);
8590 if (TREE_CODE (outer_type
) == REAL_TYPE
)
8592 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8593 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8594 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8596 if (TREE_UNSIGNED (inner_type
))
8598 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8601 else if (TREE_CODE (outer_type
) == INTEGER_TYPE
)
8603 if (TREE_CODE (inner_type
) == REAL_TYPE
)
8604 return tree_expr_nonnegative_p (TREE_OPERAND (t
,0));
8605 if (TREE_CODE (inner_type
) == INTEGER_TYPE
)
8606 return TYPE_PRECISION (inner_type
) < TYPE_PRECISION (outer_type
)
8607 && TREE_UNSIGNED (inner_type
);
8613 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
8614 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
8616 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8618 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8619 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8621 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
8622 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8624 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8626 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
8628 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8629 case NON_LVALUE_EXPR
:
8630 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8632 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
8634 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
8638 tree fndecl
= get_callee_fndecl (t
);
8639 tree arglist
= TREE_OPERAND (t
, 1);
8641 && DECL_BUILT_IN (fndecl
)
8642 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
)
8643 switch (DECL_FUNCTION_CODE (fndecl
))
8646 case BUILT_IN_CABSL
:
8647 case BUILT_IN_CABSF
:
8652 case BUILT_IN_FABSF
:
8653 case BUILT_IN_FABSL
:
8655 case BUILT_IN_SQRTF
:
8656 case BUILT_IN_SQRTL
:
8660 case BUILT_IN_ATANF
:
8661 case BUILT_IN_ATANL
:
8663 case BUILT_IN_CEILF
:
8664 case BUILT_IN_CEILL
:
8665 case BUILT_IN_FLOOR
:
8666 case BUILT_IN_FLOORF
:
8667 case BUILT_IN_FLOORL
:
8668 case BUILT_IN_NEARBYINT
:
8669 case BUILT_IN_NEARBYINTF
:
8670 case BUILT_IN_NEARBYINTL
:
8671 case BUILT_IN_ROUND
:
8672 case BUILT_IN_ROUNDF
:
8673 case BUILT_IN_ROUNDL
:
8674 case BUILT_IN_TRUNC
:
8675 case BUILT_IN_TRUNCF
:
8676 case BUILT_IN_TRUNCL
:
8677 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8682 return tree_expr_nonnegative_p (TREE_VALUE (arglist
));
8689 /* ... fall through ... */
8692 if (truth_value_p (TREE_CODE (t
)))
8693 /* Truth values evaluate to 0 or 1, which is nonnegative. */
8697 /* We don't know sign of `t', so be conservative and return false. */
8701 /* Return true if `r' is known to be non-negative.
8702 Only handles constants at the moment. */
8705 rtl_expr_nonnegative_p (rtx r
)
8707 switch (GET_CODE (r
))
8710 return INTVAL (r
) >= 0;
8713 if (GET_MODE (r
) == VOIDmode
)
8714 return CONST_DOUBLE_HIGH (r
) >= 0;
8722 units
= CONST_VECTOR_NUNITS (r
);
8724 for (i
= 0; i
< units
; ++i
)
8726 elt
= CONST_VECTOR_ELT (r
, i
);
8727 if (!rtl_expr_nonnegative_p (elt
))
8736 /* These are always nonnegative. */
8744 #include "gt-fold-const.h"