1 /* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /*@@ This file should be rewritten to use an arbitrary precision
23 @@ representation for "struct tree_int_cst" and "struct tree_real_cst".
24 @@ Perhaps the routines could also be used for bc/dc, and made a lib.
25 @@ The routines that translate from the ap rep should
26 @@ warn if precision et. al. is lost.
27 @@ This would also make life easier when this technology is used
28 @@ for cross-compilers. */
30 /* The entry points in this file are fold, size_int_wide, size_binop
33 fold takes a tree as argument and returns a simplified tree.
35 size_binop takes a tree code for an arithmetic operation
36 and two operands that are trees, and produces a tree for the
37 result, assuming the type comes from `sizetype'.
39 size_int takes an integer value, and creates a tree constant
40 with type from `sizetype'.
42 force_fit_type takes a constant and prior overflow indicator, and
43 forces the value to fit the type. It returns an overflow indicator. */
47 #include "coretypes.h"
58 #include "langhooks.h"
60 static void encode
PARAMS ((HOST_WIDE_INT
*,
61 unsigned HOST_WIDE_INT
,
63 static void decode
PARAMS ((HOST_WIDE_INT
*,
64 unsigned HOST_WIDE_INT
*,
66 static bool negate_expr_p
PARAMS ((tree
));
67 static tree negate_expr
PARAMS ((tree
));
68 static tree split_tree
PARAMS ((tree
, enum tree_code
, tree
*, tree
*,
70 static tree associate_trees
PARAMS ((tree
, tree
, enum tree_code
, tree
));
71 static tree int_const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
72 static tree const_binop
PARAMS ((enum tree_code
, tree
, tree
, int));
73 static hashval_t size_htab_hash
PARAMS ((const void *));
74 static int size_htab_eq
PARAMS ((const void *, const void *));
75 static tree fold_convert
PARAMS ((tree
, tree
));
76 static enum tree_code invert_tree_comparison
PARAMS ((enum tree_code
));
77 static enum tree_code swap_tree_comparison
PARAMS ((enum tree_code
));
78 static int comparison_to_compcode
PARAMS ((enum tree_code
));
79 static enum tree_code compcode_to_comparison
PARAMS ((int));
80 static int truth_value_p
PARAMS ((enum tree_code
));
81 static int operand_equal_for_comparison_p
PARAMS ((tree
, tree
, tree
));
82 static int twoval_comparison_p
PARAMS ((tree
, tree
*, tree
*, int *));
83 static tree eval_subst
PARAMS ((tree
, tree
, tree
, tree
, tree
));
84 static tree pedantic_omit_one_operand
PARAMS ((tree
, tree
, tree
));
85 static tree distribute_bit_expr
PARAMS ((enum tree_code
, tree
, tree
, tree
));
86 static tree make_bit_field_ref
PARAMS ((tree
, tree
, int, int, int));
87 static tree optimize_bit_field_compare
PARAMS ((enum tree_code
, tree
,
89 static tree decode_field_reference
PARAMS ((tree
, HOST_WIDE_INT
*,
91 enum machine_mode
*, int *,
92 int *, tree
*, tree
*));
93 static int all_ones_mask_p
PARAMS ((tree
, int));
94 static tree sign_bit_p
PARAMS ((tree
, tree
));
95 static int simple_operand_p
PARAMS ((tree
));
96 static tree range_binop
PARAMS ((enum tree_code
, tree
, tree
, int,
98 static tree make_range
PARAMS ((tree
, int *, tree
*, tree
*));
99 static tree build_range_check
PARAMS ((tree
, tree
, int, tree
, tree
));
100 static int merge_ranges
PARAMS ((int *, tree
*, tree
*, int, tree
, tree
,
102 static tree fold_range_test
PARAMS ((tree
));
103 static tree unextend
PARAMS ((tree
, int, int, tree
));
104 static tree fold_truthop
PARAMS ((enum tree_code
, tree
, tree
, tree
));
105 static tree optimize_minmax_comparison
PARAMS ((tree
));
106 static tree extract_muldiv
PARAMS ((tree
, tree
, enum tree_code
, tree
));
107 static tree extract_muldiv_1
PARAMS ((tree
, tree
, enum tree_code
, tree
));
108 static tree strip_compound_expr
PARAMS ((tree
, tree
));
109 static int multiple_of_p
PARAMS ((tree
, tree
, tree
));
110 static tree constant_boolean_node
PARAMS ((int, tree
));
111 static int count_cond
PARAMS ((tree
, int));
112 static tree fold_binary_op_with_conditional_arg
113 PARAMS ((enum tree_code
, tree
, tree
, tree
, int));
114 static bool fold_real_zero_addition_p
PARAMS ((tree
, tree
, int));
115 static tree fold_mathfn_compare
PARAMS ((enum built_in_function
,
116 enum tree_code
, tree
, tree
, tree
));
117 static tree fold_inf_compare
PARAMS ((enum tree_code
, tree
, tree
, tree
));
119 /* The following constants represent a bit based encoding of GCC's
120 comparison operators. This encoding simplifies transformations
121 on relational comparison operators, such as AND and OR. */
122 #define COMPCODE_FALSE 0
123 #define COMPCODE_LT 1
124 #define COMPCODE_EQ 2
125 #define COMPCODE_LE 3
126 #define COMPCODE_GT 4
127 #define COMPCODE_NE 5
128 #define COMPCODE_GE 6
129 #define COMPCODE_TRUE 7
131 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
132 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
133 and SUM1. Then this yields nonzero if overflow occurred during the
136 Overflow occurs if A and B have the same sign, but A and SUM differ in
137 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
139 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
141 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
142 We do that by representing the two-word integer in 4 words, with only
143 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
144 number. The value of the word is LOWPART + HIGHPART * BASE. */
147 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
148 #define HIGHPART(x) \
149 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
150 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
152 /* Unpack a two-word integer into 4 words.
153 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
154 WORDS points to the array of HOST_WIDE_INTs. */
157 encode (words
, low
, hi
)
158 HOST_WIDE_INT
*words
;
159 unsigned HOST_WIDE_INT low
;
162 words
[0] = LOWPART (low
);
163 words
[1] = HIGHPART (low
);
164 words
[2] = LOWPART (hi
);
165 words
[3] = HIGHPART (hi
);
168 /* Pack an array of 4 words into a two-word integer.
169 WORDS points to the array of words.
170 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
173 decode (words
, low
, hi
)
174 HOST_WIDE_INT
*words
;
175 unsigned HOST_WIDE_INT
*low
;
178 *low
= words
[0] + words
[1] * BASE
;
179 *hi
= words
[2] + words
[3] * BASE
;
182 /* Make the integer constant T valid for its type by setting to 0 or 1 all
183 the bits in the constant that don't belong in the type.
185 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
186 nonzero, a signed overflow has already occurred in calculating T, so
190 force_fit_type (t
, overflow
)
194 unsigned HOST_WIDE_INT low
;
198 if (TREE_CODE (t
) == REAL_CST
)
200 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
201 Consider doing it via real_convert now. */
205 else if (TREE_CODE (t
) != INTEGER_CST
)
208 low
= TREE_INT_CST_LOW (t
);
209 high
= TREE_INT_CST_HIGH (t
);
211 if (POINTER_TYPE_P (TREE_TYPE (t
)))
214 prec
= TYPE_PRECISION (TREE_TYPE (t
));
216 /* First clear all bits that are beyond the type's precision. */
218 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
220 else if (prec
> HOST_BITS_PER_WIDE_INT
)
221 TREE_INT_CST_HIGH (t
)
222 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
225 TREE_INT_CST_HIGH (t
) = 0;
226 if (prec
< HOST_BITS_PER_WIDE_INT
)
227 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
230 /* Unsigned types do not suffer sign extension or overflow unless they
232 if (TREE_UNSIGNED (TREE_TYPE (t
))
233 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
234 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
237 /* If the value's sign bit is set, extend the sign. */
238 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
239 && (prec
> HOST_BITS_PER_WIDE_INT
240 ? 0 != (TREE_INT_CST_HIGH (t
)
242 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
243 : 0 != (TREE_INT_CST_LOW (t
)
244 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
246 /* Value is negative:
247 set to 1 all the bits that are outside this type's precision. */
248 if (prec
> HOST_BITS_PER_WIDE_INT
)
249 TREE_INT_CST_HIGH (t
)
250 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
253 TREE_INT_CST_HIGH (t
) = -1;
254 if (prec
< HOST_BITS_PER_WIDE_INT
)
255 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
259 /* Return nonzero if signed overflow occurred. */
261 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
265 /* Add two doubleword integers with doubleword result.
266 Each argument is given as two `HOST_WIDE_INT' pieces.
267 One argument is L1 and H1; the other, L2 and H2.
268 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
271 add_double (l1
, h1
, l2
, h2
, lv
, hv
)
272 unsigned HOST_WIDE_INT l1
, l2
;
273 HOST_WIDE_INT h1
, h2
;
274 unsigned HOST_WIDE_INT
*lv
;
277 unsigned HOST_WIDE_INT l
;
281 h
= h1
+ h2
+ (l
< l1
);
285 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
288 /* Negate a doubleword integer with doubleword result.
289 Return nonzero if the operation overflows, assuming it's signed.
290 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
291 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
294 neg_double (l1
, h1
, lv
, hv
)
295 unsigned HOST_WIDE_INT l1
;
297 unsigned HOST_WIDE_INT
*lv
;
304 return (*hv
& h1
) < 0;
314 /* Multiply two doubleword integers with doubleword result.
315 Return nonzero if the operation overflows, assuming it's signed.
316 Each argument is given as two `HOST_WIDE_INT' pieces.
317 One argument is L1 and H1; the other, L2 and H2.
318 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
321 mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
322 unsigned HOST_WIDE_INT l1
, l2
;
323 HOST_WIDE_INT h1
, h2
;
324 unsigned HOST_WIDE_INT
*lv
;
327 HOST_WIDE_INT arg1
[4];
328 HOST_WIDE_INT arg2
[4];
329 HOST_WIDE_INT prod
[4 * 2];
330 unsigned HOST_WIDE_INT carry
;
332 unsigned HOST_WIDE_INT toplow
, neglow
;
333 HOST_WIDE_INT tophigh
, neghigh
;
335 encode (arg1
, l1
, h1
);
336 encode (arg2
, l2
, h2
);
338 memset ((char *) prod
, 0, sizeof prod
);
340 for (i
= 0; i
< 4; i
++)
343 for (j
= 0; j
< 4; j
++)
346 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
347 carry
+= arg1
[i
] * arg2
[j
];
348 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
350 prod
[k
] = LOWPART (carry
);
351 carry
= HIGHPART (carry
);
356 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
358 /* Check for overflow by calculating the top half of the answer in full;
359 it should agree with the low half's sign bit. */
360 decode (prod
+ 4, &toplow
, &tophigh
);
363 neg_double (l2
, h2
, &neglow
, &neghigh
);
364 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
368 neg_double (l1
, h1
, &neglow
, &neghigh
);
369 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
371 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
374 /* Shift the doubleword integer in L1, H1 left by COUNT places
375 keeping only PREC bits of result.
376 Shift right if COUNT is negative.
377 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
378 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
381 lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
382 unsigned HOST_WIDE_INT l1
;
383 HOST_WIDE_INT h1
, count
;
385 unsigned HOST_WIDE_INT
*lv
;
389 unsigned HOST_WIDE_INT signmask
;
393 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
397 #ifdef SHIFT_COUNT_TRUNCATED
398 if (SHIFT_COUNT_TRUNCATED
)
402 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
404 /* Shifting by the host word size is undefined according to the
405 ANSI standard, so we must handle this as a special case. */
409 else if (count
>= HOST_BITS_PER_WIDE_INT
)
411 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
416 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
417 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
421 /* Sign extend all bits that are beyond the precision. */
423 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
424 ? ((unsigned HOST_WIDE_INT
) *hv
425 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
426 : (*lv
>> (prec
- 1))) & 1);
428 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
430 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
432 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
433 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
438 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
439 *lv
|= signmask
<< prec
;
443 /* Shift the doubleword integer in L1, H1 right by COUNT places
444 keeping only PREC bits of result. COUNT must be positive.
445 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
446 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
449 rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
450 unsigned HOST_WIDE_INT l1
;
451 HOST_WIDE_INT h1
, count
;
453 unsigned HOST_WIDE_INT
*lv
;
457 unsigned HOST_WIDE_INT signmask
;
460 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
463 #ifdef SHIFT_COUNT_TRUNCATED
464 if (SHIFT_COUNT_TRUNCATED
)
468 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
470 /* Shifting by the host word size is undefined according to the
471 ANSI standard, so we must handle this as a special case. */
475 else if (count
>= HOST_BITS_PER_WIDE_INT
)
478 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
482 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
484 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
487 /* Zero / sign extend all bits that are beyond the precision. */
489 if (count
>= (HOST_WIDE_INT
)prec
)
494 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
496 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
498 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
499 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
504 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
505 *lv
|= signmask
<< (prec
- count
);
509 /* Rotate the doubleword integer in L1, H1 left by COUNT places
510 keeping only PREC bits of result.
511 Rotate right if COUNT is negative.
512 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
515 lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
516 unsigned HOST_WIDE_INT l1
;
517 HOST_WIDE_INT h1
, count
;
519 unsigned HOST_WIDE_INT
*lv
;
522 unsigned HOST_WIDE_INT s1l
, s2l
;
523 HOST_WIDE_INT s1h
, s2h
;
529 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
530 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
535 /* Rotate the doubleword integer in L1, H1 left by COUNT places
536 keeping only PREC bits of result. COUNT must be positive.
537 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
540 rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
541 unsigned HOST_WIDE_INT l1
;
542 HOST_WIDE_INT h1
, count
;
544 unsigned HOST_WIDE_INT
*lv
;
547 unsigned HOST_WIDE_INT s1l
, s2l
;
548 HOST_WIDE_INT s1h
, s2h
;
554 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
555 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
560 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
561 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
562 CODE is a tree code for a kind of division, one of
563 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
565 It controls how the quotient is rounded to an integer.
566 Return nonzero if the operation overflows.
567 UNS nonzero says do unsigned division. */
570 div_and_round_double (code
, uns
,
571 lnum_orig
, hnum_orig
, lden_orig
, hden_orig
,
572 lquo
, hquo
, lrem
, hrem
)
575 unsigned HOST_WIDE_INT lnum_orig
; /* num == numerator == dividend */
576 HOST_WIDE_INT hnum_orig
;
577 unsigned HOST_WIDE_INT lden_orig
; /* den == denominator == divisor */
578 HOST_WIDE_INT hden_orig
;
579 unsigned HOST_WIDE_INT
*lquo
, *lrem
;
580 HOST_WIDE_INT
*hquo
, *hrem
;
583 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
584 HOST_WIDE_INT den
[4], quo
[4];
586 unsigned HOST_WIDE_INT work
;
587 unsigned HOST_WIDE_INT carry
= 0;
588 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
589 HOST_WIDE_INT hnum
= hnum_orig
;
590 unsigned HOST_WIDE_INT lden
= lden_orig
;
591 HOST_WIDE_INT hden
= hden_orig
;
594 if (hden
== 0 && lden
== 0)
595 overflow
= 1, lden
= 1;
597 /* calculate quotient sign and convert operands to unsigned. */
603 /* (minimum integer) / (-1) is the only overflow case. */
604 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
605 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
611 neg_double (lden
, hden
, &lden
, &hden
);
615 if (hnum
== 0 && hden
== 0)
616 { /* single precision */
618 /* This unsigned division rounds toward zero. */
624 { /* trivial case: dividend < divisor */
625 /* hden != 0 already checked. */
632 memset ((char *) quo
, 0, sizeof quo
);
634 memset ((char *) num
, 0, sizeof num
); /* to zero 9th element */
635 memset ((char *) den
, 0, sizeof den
);
637 encode (num
, lnum
, hnum
);
638 encode (den
, lden
, hden
);
640 /* Special code for when the divisor < BASE. */
641 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
643 /* hnum != 0 already checked. */
644 for (i
= 4 - 1; i
>= 0; i
--)
646 work
= num
[i
] + carry
* BASE
;
647 quo
[i
] = work
/ lden
;
653 /* Full double precision division,
654 with thanks to Don Knuth's "Seminumerical Algorithms". */
655 int num_hi_sig
, den_hi_sig
;
656 unsigned HOST_WIDE_INT quo_est
, scale
;
658 /* Find the highest nonzero divisor digit. */
659 for (i
= 4 - 1;; i
--)
666 /* Insure that the first digit of the divisor is at least BASE/2.
667 This is required by the quotient digit estimation algorithm. */
669 scale
= BASE
/ (den
[den_hi_sig
] + 1);
671 { /* scale divisor and dividend */
673 for (i
= 0; i
<= 4 - 1; i
++)
675 work
= (num
[i
] * scale
) + carry
;
676 num
[i
] = LOWPART (work
);
677 carry
= HIGHPART (work
);
682 for (i
= 0; i
<= 4 - 1; i
++)
684 work
= (den
[i
] * scale
) + carry
;
685 den
[i
] = LOWPART (work
);
686 carry
= HIGHPART (work
);
687 if (den
[i
] != 0) den_hi_sig
= i
;
694 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
696 /* Guess the next quotient digit, quo_est, by dividing the first
697 two remaining dividend digits by the high order quotient digit.
698 quo_est is never low and is at most 2 high. */
699 unsigned HOST_WIDE_INT tmp
;
701 num_hi_sig
= i
+ den_hi_sig
+ 1;
702 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
703 if (num
[num_hi_sig
] != den
[den_hi_sig
])
704 quo_est
= work
/ den
[den_hi_sig
];
708 /* Refine quo_est so it's usually correct, and at most one high. */
709 tmp
= work
- quo_est
* den
[den_hi_sig
];
711 && (den
[den_hi_sig
- 1] * quo_est
712 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
715 /* Try QUO_EST as the quotient digit, by multiplying the
716 divisor by QUO_EST and subtracting from the remaining dividend.
717 Keep in mind that QUO_EST is the I - 1st digit. */
720 for (j
= 0; j
<= den_hi_sig
; j
++)
722 work
= quo_est
* den
[j
] + carry
;
723 carry
= HIGHPART (work
);
724 work
= num
[i
+ j
] - LOWPART (work
);
725 num
[i
+ j
] = LOWPART (work
);
726 carry
+= HIGHPART (work
) != 0;
729 /* If quo_est was high by one, then num[i] went negative and
730 we need to correct things. */
731 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
734 carry
= 0; /* add divisor back in */
735 for (j
= 0; j
<= den_hi_sig
; j
++)
737 work
= num
[i
+ j
] + den
[j
] + carry
;
738 carry
= HIGHPART (work
);
739 num
[i
+ j
] = LOWPART (work
);
742 num
[num_hi_sig
] += carry
;
745 /* Store the quotient digit. */
750 decode (quo
, lquo
, hquo
);
753 /* if result is negative, make it so. */
755 neg_double (*lquo
, *hquo
, lquo
, hquo
);
757 /* compute trial remainder: rem = num - (quo * den) */
758 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
759 neg_double (*lrem
, *hrem
, lrem
, hrem
);
760 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
765 case TRUNC_MOD_EXPR
: /* round toward zero */
766 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
770 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
771 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
774 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
782 case CEIL_MOD_EXPR
: /* round toward positive infinity */
783 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
785 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
793 case ROUND_MOD_EXPR
: /* round to closest integer */
795 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
796 HOST_WIDE_INT habs_rem
= *hrem
;
797 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
798 HOST_WIDE_INT habs_den
= hden
, htwice
;
800 /* Get absolute values */
802 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
804 neg_double (lden
, hden
, &labs_den
, &habs_den
);
806 /* If (2 * abs (lrem) >= abs (lden)) */
807 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
808 labs_rem
, habs_rem
, <wice
, &htwice
);
810 if (((unsigned HOST_WIDE_INT
) habs_den
811 < (unsigned HOST_WIDE_INT
) htwice
)
812 || (((unsigned HOST_WIDE_INT
) habs_den
813 == (unsigned HOST_WIDE_INT
) htwice
)
814 && (labs_den
< ltwice
)))
818 add_double (*lquo
, *hquo
,
819 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
822 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
834 /* compute true remainder: rem = num - (quo * den) */
835 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
836 neg_double (*lrem
, *hrem
, lrem
, hrem
);
837 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
841 /* Determine whether an expression T can be cheaply negated using
842 the function negate_expr. */
848 unsigned HOST_WIDE_INT val
;
855 type
= TREE_TYPE (t
);
858 switch (TREE_CODE (t
))
861 if (TREE_UNSIGNED (type
))
864 /* Check that -CST will not overflow type. */
865 prec
= TYPE_PRECISION (type
);
866 if (prec
> HOST_BITS_PER_WIDE_INT
)
868 if (TREE_INT_CST_LOW (t
) != 0)
870 prec
-= HOST_BITS_PER_WIDE_INT
;
871 val
= TREE_INT_CST_HIGH (t
);
874 val
= TREE_INT_CST_LOW (t
);
875 if (prec
< HOST_BITS_PER_WIDE_INT
)
876 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
877 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
890 /* Given T, an expression, return the negation of T. Allow for T to be
891 null, in which case return null. */
903 type
= TREE_TYPE (t
);
906 switch (TREE_CODE (t
))
910 if (! TREE_UNSIGNED (type
)
911 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
912 && ! TREE_OVERFLOW (tem
))
917 return convert (type
, TREE_OPERAND (t
, 0));
920 /* - (A - B) -> B - A */
921 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
922 return convert (type
,
923 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
925 TREE_OPERAND (t
, 0))));
932 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
935 /* Split a tree IN into a constant, literal and variable parts that could be
936 combined with CODE to make IN. "constant" means an expression with
937 TREE_CONSTANT but that isn't an actual constant. CODE must be a
938 commutative arithmetic operation. Store the constant part into *CONP,
939 the literal in *LITP and return the variable part. If a part isn't
940 present, set it to null. If the tree does not decompose in this way,
941 return the entire tree as the variable part and the other parts as null.
943 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
944 case, we negate an operand that was subtracted. Except if it is a
945 literal for which we use *MINUS_LITP instead.
947 If NEGATE_P is true, we are negating all of IN, again except a literal
948 for which we use *MINUS_LITP instead.
950 If IN is itself a literal or constant, return it as appropriate.
952 Note that we do not guarantee that any of the three values will be the
953 same type as IN, but they will have the same signedness and mode. */
956 split_tree (in
, code
, conp
, litp
, minus_litp
, negate_p
)
959 tree
*conp
, *litp
, *minus_litp
;
968 /* Strip any conversions that don't change the machine mode or signedness. */
969 STRIP_SIGN_NOPS (in
);
971 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
973 else if (TREE_CODE (in
) == code
974 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
975 /* We can associate addition and subtraction together (even
976 though the C standard doesn't say so) for integers because
977 the value is not affected. For reals, the value might be
978 affected, so we can't. */
979 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
980 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
982 tree op0
= TREE_OPERAND (in
, 0);
983 tree op1
= TREE_OPERAND (in
, 1);
984 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
985 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
987 /* First see if either of the operands is a literal, then a constant. */
988 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
989 *litp
= op0
, op0
= 0;
990 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
991 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
993 if (op0
!= 0 && TREE_CONSTANT (op0
))
994 *conp
= op0
, op0
= 0;
995 else if (op1
!= 0 && TREE_CONSTANT (op1
))
996 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
998 /* If we haven't dealt with either operand, this is not a case we can
999 decompose. Otherwise, VAR is either of the ones remaining, if any. */
1000 if (op0
!= 0 && op1
!= 0)
1005 var
= op1
, neg_var_p
= neg1_p
;
1007 /* Now do any needed negations. */
1009 *minus_litp
= *litp
, *litp
= 0;
1011 *conp
= negate_expr (*conp
);
1013 var
= negate_expr (var
);
1015 else if (TREE_CONSTANT (in
))
1023 *minus_litp
= *litp
, *litp
= 0;
1024 else if (*minus_litp
)
1025 *litp
= *minus_litp
, *minus_litp
= 0;
1026 *conp
= negate_expr (*conp
);
1027 var
= negate_expr (var
);
1033 /* Re-associate trees split by the above function. T1 and T2 are either
1034 expressions to associate or null. Return the new expression, if any. If
1035 we build an operation, do it in TYPE and with CODE. */
1038 associate_trees (t1
, t2
, code
, type
)
1040 enum tree_code code
;
1048 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1049 try to fold this since we will have infinite recursion. But do
1050 deal with any NEGATE_EXPRs. */
1051 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1052 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1054 if (code
== PLUS_EXPR
)
1056 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1057 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1058 convert (type
, TREE_OPERAND (t1
, 0)));
1059 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1060 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1061 convert (type
, TREE_OPERAND (t2
, 0)));
1063 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1066 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1069 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1070 to produce a new constant.
1072 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1075 int_const_binop (code
, arg1
, arg2
, notrunc
)
1076 enum tree_code code
;
1080 unsigned HOST_WIDE_INT int1l
, int2l
;
1081 HOST_WIDE_INT int1h
, int2h
;
1082 unsigned HOST_WIDE_INT low
;
1084 unsigned HOST_WIDE_INT garbagel
;
1085 HOST_WIDE_INT garbageh
;
1087 tree type
= TREE_TYPE (arg1
);
1088 int uns
= TREE_UNSIGNED (type
);
1090 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1092 int no_overflow
= 0;
1094 int1l
= TREE_INT_CST_LOW (arg1
);
1095 int1h
= TREE_INT_CST_HIGH (arg1
);
1096 int2l
= TREE_INT_CST_LOW (arg2
);
1097 int2h
= TREE_INT_CST_HIGH (arg2
);
1102 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1106 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1110 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1113 case BIT_ANDTC_EXPR
:
1114 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1120 /* It's unclear from the C standard whether shifts can overflow.
1121 The following code ignores overflow; perhaps a C standard
1122 interpretation ruling is needed. */
1123 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1131 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1136 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1140 neg_double (int2l
, int2h
, &low
, &hi
);
1141 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1142 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1146 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1149 case TRUNC_DIV_EXPR
:
1150 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1151 case EXACT_DIV_EXPR
:
1152 /* This is a shortcut for a common special case. */
1153 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1154 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1155 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1156 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1158 if (code
== CEIL_DIV_EXPR
)
1161 low
= int1l
/ int2l
, hi
= 0;
1165 /* ... fall through ... */
1167 case ROUND_DIV_EXPR
:
1168 if (int2h
== 0 && int2l
== 1)
1170 low
= int1l
, hi
= int1h
;
1173 if (int1l
== int2l
&& int1h
== int2h
1174 && ! (int1l
== 0 && int1h
== 0))
1179 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1180 &low
, &hi
, &garbagel
, &garbageh
);
1183 case TRUNC_MOD_EXPR
:
1184 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1185 /* This is a shortcut for a common special case. */
1186 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1187 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1188 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1189 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1191 if (code
== CEIL_MOD_EXPR
)
1193 low
= int1l
% int2l
, hi
= 0;
1197 /* ... fall through ... */
1199 case ROUND_MOD_EXPR
:
1200 overflow
= div_and_round_double (code
, uns
,
1201 int1l
, int1h
, int2l
, int2h
,
1202 &garbagel
, &garbageh
, &low
, &hi
);
1208 low
= (((unsigned HOST_WIDE_INT
) int1h
1209 < (unsigned HOST_WIDE_INT
) int2h
)
1210 || (((unsigned HOST_WIDE_INT
) int1h
1211 == (unsigned HOST_WIDE_INT
) int2h
)
1214 low
= (int1h
< int2h
1215 || (int1h
== int2h
&& int1l
< int2l
));
1217 if (low
== (code
== MIN_EXPR
))
1218 low
= int1l
, hi
= int1h
;
1220 low
= int2l
, hi
= int2h
;
1227 /* If this is for a sizetype, can be represented as one (signed)
1228 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1231 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1232 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1233 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1234 return size_int_type_wide (low
, type
);
1237 t
= build_int_2 (low
, hi
);
1238 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1243 ? (!uns
|| is_sizetype
) && overflow
1244 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1246 | TREE_OVERFLOW (arg1
)
1247 | TREE_OVERFLOW (arg2
));
1249 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1250 So check if force_fit_type truncated the value. */
1252 && ! TREE_OVERFLOW (t
)
1253 && (TREE_INT_CST_HIGH (t
) != hi
1254 || TREE_INT_CST_LOW (t
) != low
))
1255 TREE_OVERFLOW (t
) = 1;
1257 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1258 | TREE_CONSTANT_OVERFLOW (arg1
)
1259 | TREE_CONSTANT_OVERFLOW (arg2
));
1263 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1264 constant. We assume ARG1 and ARG2 have the same data type, or at least
1265 are the same kind of constant and the same machine mode.
1267 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1270 const_binop (code
, arg1
, arg2
, notrunc
)
1271 enum tree_code code
;
1278 if (TREE_CODE (arg1
) == INTEGER_CST
)
1279 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1281 if (TREE_CODE (arg1
) == REAL_CST
)
1285 REAL_VALUE_TYPE value
;
1288 d1
= TREE_REAL_CST (arg1
);
1289 d2
= TREE_REAL_CST (arg2
);
1291 /* If either operand is a NaN, just return it. Otherwise, set up
1292 for floating-point trap; we return an overflow. */
1293 if (REAL_VALUE_ISNAN (d1
))
1295 else if (REAL_VALUE_ISNAN (d2
))
1298 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1300 t
= build_real (TREE_TYPE (arg1
),
1301 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1
)),
1305 = (force_fit_type (t
, 0)
1306 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1307 TREE_CONSTANT_OVERFLOW (t
)
1309 | TREE_CONSTANT_OVERFLOW (arg1
)
1310 | TREE_CONSTANT_OVERFLOW (arg2
);
1313 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1315 tree type
= TREE_TYPE (arg1
);
1316 tree r1
= TREE_REALPART (arg1
);
1317 tree i1
= TREE_IMAGPART (arg1
);
1318 tree r2
= TREE_REALPART (arg2
);
1319 tree i2
= TREE_IMAGPART (arg2
);
1325 t
= build_complex (type
,
1326 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1327 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1331 t
= build_complex (type
,
1332 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1333 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1337 t
= build_complex (type
,
1338 const_binop (MINUS_EXPR
,
1339 const_binop (MULT_EXPR
,
1341 const_binop (MULT_EXPR
,
1344 const_binop (PLUS_EXPR
,
1345 const_binop (MULT_EXPR
,
1347 const_binop (MULT_EXPR
,
1355 = const_binop (PLUS_EXPR
,
1356 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1357 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1360 t
= build_complex (type
,
1362 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1363 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1364 const_binop (PLUS_EXPR
,
1365 const_binop (MULT_EXPR
, r1
, r2
,
1367 const_binop (MULT_EXPR
, i1
, i2
,
1370 magsquared
, notrunc
),
1372 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1373 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1374 const_binop (MINUS_EXPR
,
1375 const_binop (MULT_EXPR
, i1
, r2
,
1377 const_binop (MULT_EXPR
, r1
, i2
,
1380 magsquared
, notrunc
));
1392 /* These are the hash table functions for the hash table of INTEGER_CST
1393 nodes of a sizetype. */
1395 /* Return the hash code code X, an INTEGER_CST. */
1403 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1404 ^ htab_hash_pointer (TREE_TYPE (t
))
1405 ^ (TREE_OVERFLOW (t
) << 20));
1408 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1409 is the same as that given by *Y, which is the same. */
1419 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1420 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1421 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1422 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1425 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1426 bits are given by NUMBER and of the sizetype represented by KIND. */
1429 size_int_wide (number
, kind
)
1430 HOST_WIDE_INT number
;
1431 enum size_type_kind kind
;
1433 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1436 /* Likewise, but the desired type is specified explicitly. */
1438 static GTY (()) tree new_const
;
1439 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1443 size_int_type_wide (number
, type
)
1444 HOST_WIDE_INT number
;
1451 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1452 new_const
= make_node (INTEGER_CST
);
1455 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1456 hash table, we return the value from the hash table. Otherwise, we
1457 place that in the hash table and make a new node for the next time. */
1458 TREE_INT_CST_LOW (new_const
) = number
;
1459 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1460 TREE_TYPE (new_const
) = type
;
1461 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1462 = force_fit_type (new_const
, 0);
1464 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1469 *slot
= (PTR
) new_const
;
1470 new_const
= make_node (INTEGER_CST
);
1474 return (tree
) *slot
;
1477 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1478 is a tree code. The type of the result is taken from the operands.
1479 Both must be the same type integer type and it must be a size type.
1480 If the operands are constant, so is the result. */
1483 size_binop (code
, arg0
, arg1
)
1484 enum tree_code code
;
1487 tree type
= TREE_TYPE (arg0
);
1489 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1490 || type
!= TREE_TYPE (arg1
))
1493 /* Handle the special case of two integer constants faster. */
1494 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1496 /* And some specific cases even faster than that. */
1497 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1499 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1500 && integer_zerop (arg1
))
1502 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1505 /* Handle general case of two integer constants. */
1506 return int_const_binop (code
, arg0
, arg1
, 0);
1509 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1510 return error_mark_node
;
1512 return fold (build (code
, type
, arg0
, arg1
));
1515 /* Given two values, either both of sizetype or both of bitsizetype,
1516 compute the difference between the two values. Return the value
1517 in signed type corresponding to the type of the operands. */
1520 size_diffop (arg0
, 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 (t
, arg1
)
1566 tree type
= TREE_TYPE (t
);
1569 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1571 if (TREE_CODE (arg1
) == INTEGER_CST
)
1573 /* If we would build a constant wider than GCC supports,
1574 leave the conversion unfolded. */
1575 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1578 /* If we are trying to make a sizetype for a small integer, use
1579 size_int to pick up cached types to reduce duplicate nodes. */
1580 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1581 && !TREE_CONSTANT_OVERFLOW (arg1
)
1582 && compare_tree_int (arg1
, 10000) < 0)
1583 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1585 /* Given an integer constant, make new constant with new type,
1586 appropriately sign-extended or truncated. */
1587 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1588 TREE_INT_CST_HIGH (arg1
));
1589 TREE_TYPE (t
) = type
;
1590 /* Indicate an overflow if (1) ARG1 already overflowed,
1591 or (2) force_fit_type indicates an overflow.
1592 Tell force_fit_type that an overflow has already occurred
1593 if ARG1 is a too-large unsigned value and T is signed.
1594 But don't indicate an overflow if converting a pointer. */
1596 = ((force_fit_type (t
,
1597 (TREE_INT_CST_HIGH (arg1
) < 0
1598 && (TREE_UNSIGNED (type
)
1599 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1600 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1601 || TREE_OVERFLOW (arg1
));
1602 TREE_CONSTANT_OVERFLOW (t
)
1603 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1605 else if (TREE_CODE (arg1
) == REAL_CST
)
1607 /* Don't initialize these, use assignments.
1608 Initialized local aggregates don't work on old compilers. */
1612 tree type1
= TREE_TYPE (arg1
);
1615 x
= TREE_REAL_CST (arg1
);
1616 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1618 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1619 if (!no_upper_bound
)
1620 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1622 /* See if X will be in range after truncation towards 0.
1623 To compensate for truncation, move the bounds away from 0,
1624 but reject if X exactly equals the adjusted bounds. */
1625 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1626 if (!no_upper_bound
)
1627 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1628 /* If X is a NaN, use zero instead and show we have an overflow.
1629 Otherwise, range check. */
1630 if (REAL_VALUE_ISNAN (x
))
1631 overflow
= 1, x
= dconst0
;
1632 else if (! (REAL_VALUES_LESS (l
, x
)
1634 && REAL_VALUES_LESS (x
, u
)))
1638 HOST_WIDE_INT low
, high
;
1639 REAL_VALUE_TO_INT (&low
, &high
, x
);
1640 t
= build_int_2 (low
, high
);
1642 TREE_TYPE (t
) = type
;
1644 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1645 TREE_CONSTANT_OVERFLOW (t
)
1646 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1648 TREE_TYPE (t
) = type
;
1650 else if (TREE_CODE (type
) == REAL_TYPE
)
1652 if (TREE_CODE (arg1
) == INTEGER_CST
)
1653 return build_real_from_int_cst (type
, arg1
);
1654 if (TREE_CODE (arg1
) == REAL_CST
)
1656 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1658 /* We make a copy of ARG1 so that we don't modify an
1659 existing constant tree. */
1660 t
= copy_node (arg1
);
1661 TREE_TYPE (t
) = type
;
1665 t
= build_real (type
,
1666 real_value_truncate (TYPE_MODE (type
),
1667 TREE_REAL_CST (arg1
)));
1670 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1671 TREE_CONSTANT_OVERFLOW (t
)
1672 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1676 TREE_CONSTANT (t
) = 1;
1680 /* Return an expr equal to X but certainly not valid as an lvalue. */
1688 /* These things are certainly not lvalues. */
1689 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1690 || TREE_CODE (x
) == INTEGER_CST
1691 || TREE_CODE (x
) == REAL_CST
1692 || TREE_CODE (x
) == STRING_CST
1693 || TREE_CODE (x
) == ADDR_EXPR
)
1696 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1697 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1701 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1702 Zero means allow extended lvalues. */
1704 int pedantic_lvalues
;
1706 /* When pedantic, return an expr equal to X but certainly not valid as a
1707 pedantic lvalue. Otherwise, return X. */
1710 pedantic_non_lvalue (x
)
1713 if (pedantic_lvalues
)
1714 return non_lvalue (x
);
1719 /* Given a tree comparison code, return the code that is the logical inverse
1720 of the given code. It is not safe to do this for floating-point
1721 comparisons, except for NE_EXPR and EQ_EXPR. */
1723 static enum tree_code
1724 invert_tree_comparison (code
)
1725 enum tree_code code
;
1746 /* Similar, but return the comparison that results if the operands are
1747 swapped. This is safe for floating-point. */
1749 static enum tree_code
1750 swap_tree_comparison (code
)
1751 enum tree_code code
;
1772 /* Convert a comparison tree code from an enum tree_code representation
1773 into a compcode bit-based encoding. This function is the inverse of
1774 compcode_to_comparison. */
1777 comparison_to_compcode (code
)
1778 enum tree_code code
;
1799 /* Convert a compcode bit-based encoding of a comparison operator back
1800 to GCC's enum tree_code representation. This function is the
1801 inverse of comparison_to_compcode. */
1803 static enum tree_code
1804 compcode_to_comparison (code
)
1826 /* Return nonzero if CODE is a tree code that represents a truth value. */
1829 truth_value_p (code
)
1830 enum tree_code code
;
1832 return (TREE_CODE_CLASS (code
) == '<'
1833 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
1834 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
1835 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
1838 /* Return nonzero if two operands are necessarily equal.
1839 If ONLY_CONST is nonzero, only return nonzero for constants.
1840 This function tests whether the operands are indistinguishable;
1841 it does not test whether they are equal using C's == operation.
1842 The distinction is important for IEEE floating point, because
1843 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1844 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1847 operand_equal_p (arg0
, arg1
, only_const
)
1851 /* If both types don't have the same signedness, then we can't consider
1852 them equal. We must check this before the STRIP_NOPS calls
1853 because they may change the signedness of the arguments. */
1854 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
1860 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
1861 /* This is needed for conversions and for COMPONENT_REF.
1862 Might as well play it safe and always test this. */
1863 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
1864 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
1865 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
1868 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1869 We don't care about side effects in that case because the SAVE_EXPR
1870 takes care of that for us. In all other cases, two expressions are
1871 equal if they have no side effects. If we have two identical
1872 expressions with side effects that should be treated the same due
1873 to the only side effects being identical SAVE_EXPR's, that will
1874 be detected in the recursive calls below. */
1875 if (arg0
== arg1
&& ! only_const
1876 && (TREE_CODE (arg0
) == SAVE_EXPR
1877 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
1880 /* Next handle constant cases, those for which we can return 1 even
1881 if ONLY_CONST is set. */
1882 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
1883 switch (TREE_CODE (arg0
))
1886 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1887 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1888 && tree_int_cst_equal (arg0
, arg1
));
1891 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1892 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1893 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
1894 TREE_REAL_CST (arg1
)));
1900 if (TREE_CONSTANT_OVERFLOW (arg0
)
1901 || TREE_CONSTANT_OVERFLOW (arg1
))
1904 v1
= TREE_VECTOR_CST_ELTS (arg0
);
1905 v2
= TREE_VECTOR_CST_ELTS (arg1
);
1908 if (!operand_equal_p (v1
, v2
, only_const
))
1910 v1
= TREE_CHAIN (v1
);
1911 v2
= TREE_CHAIN (v2
);
1918 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
1920 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
1924 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
1925 && ! memcmp (TREE_STRING_POINTER (arg0
),
1926 TREE_STRING_POINTER (arg1
),
1927 TREE_STRING_LENGTH (arg0
)));
1930 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
1939 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
1942 /* Two conversions are equal only if signedness and modes match. */
1943 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
1944 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
1945 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
1948 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1949 TREE_OPERAND (arg1
, 0), 0);
1953 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
1954 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
1958 /* For commutative ops, allow the other order. */
1959 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
1960 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
1961 || TREE_CODE (arg0
) == BIT_IOR_EXPR
1962 || TREE_CODE (arg0
) == BIT_XOR_EXPR
1963 || TREE_CODE (arg0
) == BIT_AND_EXPR
1964 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
1965 && operand_equal_p (TREE_OPERAND (arg0
, 0),
1966 TREE_OPERAND (arg1
, 1), 0)
1967 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1968 TREE_OPERAND (arg1
, 0), 0));
1971 /* If either of the pointer (or reference) expressions we are dereferencing
1972 contain a side effect, these cannot be equal. */
1973 if (TREE_SIDE_EFFECTS (arg0
)
1974 || TREE_SIDE_EFFECTS (arg1
))
1977 switch (TREE_CODE (arg0
))
1980 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1981 TREE_OPERAND (arg1
, 0), 0);
1985 case ARRAY_RANGE_REF
:
1986 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1987 TREE_OPERAND (arg1
, 0), 0)
1988 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1989 TREE_OPERAND (arg1
, 1), 0));
1992 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1993 TREE_OPERAND (arg1
, 0), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1995 TREE_OPERAND (arg1
, 1), 0)
1996 && operand_equal_p (TREE_OPERAND (arg0
, 2),
1997 TREE_OPERAND (arg1
, 2), 0));
2003 if (TREE_CODE (arg0
) == RTL_EXPR
)
2004 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2012 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2013 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2015 When in doubt, return 0. */
2018 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2022 int unsignedp1
, unsignedpo
;
2023 tree primarg0
, primarg1
, primother
;
2024 unsigned int correct_width
;
2026 if (operand_equal_p (arg0
, arg1
, 0))
2029 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2030 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2033 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2034 and see if the inner values are the same. This removes any
2035 signedness comparison, which doesn't matter here. */
2036 primarg0
= arg0
, primarg1
= arg1
;
2037 STRIP_NOPS (primarg0
);
2038 STRIP_NOPS (primarg1
);
2039 if (operand_equal_p (primarg0
, primarg1
, 0))
2042 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2043 actual comparison operand, ARG0.
2045 First throw away any conversions to wider types
2046 already present in the operands. */
2048 primarg1
= get_narrower (arg1
, &unsignedp1
);
2049 primother
= get_narrower (other
, &unsignedpo
);
2051 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2052 if (unsignedp1
== unsignedpo
2053 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2054 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2056 tree type
= TREE_TYPE (arg0
);
2058 /* Make sure shorter operand is extended the right way
2059 to match the longer operand. */
2060 primarg1
= convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2061 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2063 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2070 /* See if ARG is an expression that is either a comparison or is performing
2071 arithmetic on comparisons. The comparisons must only be comparing
2072 two different values, which will be stored in *CVAL1 and *CVAL2; if
2073 they are nonzero it means that some operands have already been found.
2074 No variables may be used anywhere else in the expression except in the
2075 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2076 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2078 If this is true, return 1. Otherwise, return zero. */
2081 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2083 tree
*cval1
, *cval2
;
2086 enum tree_code code
= TREE_CODE (arg
);
2087 char class = TREE_CODE_CLASS (code
);
2089 /* We can handle some of the 'e' cases here. */
2090 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2092 else if (class == 'e'
2093 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2094 || code
== COMPOUND_EXPR
))
2097 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2098 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2100 /* If we've already found a CVAL1 or CVAL2, this expression is
2101 two complex to handle. */
2102 if (*cval1
|| *cval2
)
2112 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2115 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2116 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2117 cval1
, cval2
, save_p
));
2123 if (code
== COND_EXPR
)
2124 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2125 cval1
, cval2
, save_p
)
2126 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2127 cval1
, cval2
, save_p
)
2128 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2129 cval1
, cval2
, save_p
));
2133 /* First see if we can handle the first operand, then the second. For
2134 the second operand, we know *CVAL1 can't be zero. It must be that
2135 one side of the comparison is each of the values; test for the
2136 case where this isn't true by failing if the two operands
2139 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2140 TREE_OPERAND (arg
, 1), 0))
2144 *cval1
= TREE_OPERAND (arg
, 0);
2145 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2147 else if (*cval2
== 0)
2148 *cval2
= TREE_OPERAND (arg
, 0);
2149 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2154 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2156 else if (*cval2
== 0)
2157 *cval2
= TREE_OPERAND (arg
, 1);
2158 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2170 /* ARG is a tree that is known to contain just arithmetic operations and
2171 comparisons. Evaluate the operations in the tree substituting NEW0 for
2172 any occurrence of OLD0 as an operand of a comparison and likewise for
2176 eval_subst (arg
, old0
, new0
, old1
, new1
)
2178 tree old0
, new0
, old1
, new1
;
2180 tree type
= TREE_TYPE (arg
);
2181 enum tree_code code
= TREE_CODE (arg
);
2182 char class = TREE_CODE_CLASS (code
);
2184 /* We can handle some of the 'e' cases here. */
2185 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2187 else if (class == 'e'
2188 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2194 return fold (build1 (code
, type
,
2195 eval_subst (TREE_OPERAND (arg
, 0),
2196 old0
, new0
, old1
, new1
)));
2199 return fold (build (code
, type
,
2200 eval_subst (TREE_OPERAND (arg
, 0),
2201 old0
, new0
, old1
, new1
),
2202 eval_subst (TREE_OPERAND (arg
, 1),
2203 old0
, new0
, old1
, new1
)));
2209 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2212 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2215 return fold (build (code
, type
,
2216 eval_subst (TREE_OPERAND (arg
, 0),
2217 old0
, new0
, old1
, new1
),
2218 eval_subst (TREE_OPERAND (arg
, 1),
2219 old0
, new0
, old1
, new1
),
2220 eval_subst (TREE_OPERAND (arg
, 2),
2221 old0
, new0
, old1
, new1
)));
2225 /* fall through - ??? */
2229 tree arg0
= TREE_OPERAND (arg
, 0);
2230 tree arg1
= TREE_OPERAND (arg
, 1);
2232 /* We need to check both for exact equality and tree equality. The
2233 former will be true if the operand has a side-effect. In that
2234 case, we know the operand occurred exactly once. */
2236 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2238 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2241 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2243 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2246 return fold (build (code
, type
, arg0
, arg1
));
2254 /* Return a tree for the case when the result of an expression is RESULT
2255 converted to TYPE and OMITTED was previously an operand of the expression
2256 but is now not needed (e.g., we folded OMITTED * 0).
2258 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2259 the conversion of RESULT to TYPE. */
2262 omit_one_operand (type
, result
, omitted
)
2263 tree type
, result
, omitted
;
2265 tree t
= convert (type
, result
);
2267 if (TREE_SIDE_EFFECTS (omitted
))
2268 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2270 return non_lvalue (t
);
2273 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2276 pedantic_omit_one_operand (type
, result
, omitted
)
2277 tree type
, result
, omitted
;
2279 tree t
= convert (type
, result
);
2281 if (TREE_SIDE_EFFECTS (omitted
))
2282 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2284 return pedantic_non_lvalue (t
);
2287 /* Return a simplified tree node for the truth-negation of ARG. This
2288 never alters ARG itself. We assume that ARG is an operation that
2289 returns a truth value (0 or 1). */
2292 invert_truthvalue (arg
)
2295 tree type
= TREE_TYPE (arg
);
2296 enum tree_code code
= TREE_CODE (arg
);
2298 if (code
== ERROR_MARK
)
2301 /* If this is a comparison, we can simply invert it, except for
2302 floating-point non-equality comparisons, in which case we just
2303 enclose a TRUTH_NOT_EXPR around what we have. */
2305 if (TREE_CODE_CLASS (code
) == '<')
2307 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2308 && !flag_unsafe_math_optimizations
2311 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2313 return build (invert_tree_comparison (code
), type
,
2314 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2320 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2322 case TRUTH_AND_EXPR
:
2323 return build (TRUTH_OR_EXPR
, type
,
2324 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2325 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2328 return build (TRUTH_AND_EXPR
, type
,
2329 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2330 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2332 case TRUTH_XOR_EXPR
:
2333 /* Here we can invert either operand. We invert the first operand
2334 unless the second operand is a TRUTH_NOT_EXPR in which case our
2335 result is the XOR of the first operand with the inside of the
2336 negation of the second operand. */
2338 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2339 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2340 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2342 return build (TRUTH_XOR_EXPR
, type
,
2343 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2344 TREE_OPERAND (arg
, 1));
2346 case TRUTH_ANDIF_EXPR
:
2347 return build (TRUTH_ORIF_EXPR
, type
,
2348 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2349 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2351 case TRUTH_ORIF_EXPR
:
2352 return build (TRUTH_ANDIF_EXPR
, type
,
2353 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2354 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2356 case TRUTH_NOT_EXPR
:
2357 return TREE_OPERAND (arg
, 0);
2360 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2361 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2362 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2365 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2366 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2368 case WITH_RECORD_EXPR
:
2369 return build (WITH_RECORD_EXPR
, type
,
2370 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2371 TREE_OPERAND (arg
, 1));
2373 case NON_LVALUE_EXPR
:
2374 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2379 return build1 (TREE_CODE (arg
), type
,
2380 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2383 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2385 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2388 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2390 case CLEANUP_POINT_EXPR
:
2391 return build1 (CLEANUP_POINT_EXPR
, type
,
2392 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2397 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2399 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2402 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2403 operands are another bit-wise operation with a common input. If so,
2404 distribute the bit operations to save an operation and possibly two if
2405 constants are involved. For example, convert
2406 (A | B) & (A | C) into A | (B & C)
2407 Further simplification will occur if B and C are constants.
2409 If this optimization cannot be done, 0 will be returned. */
2412 distribute_bit_expr (code
, type
, arg0
, arg1
)
2413 enum tree_code code
;
2420 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2421 || TREE_CODE (arg0
) == code
2422 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2423 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2426 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2428 common
= TREE_OPERAND (arg0
, 0);
2429 left
= TREE_OPERAND (arg0
, 1);
2430 right
= TREE_OPERAND (arg1
, 1);
2432 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2434 common
= TREE_OPERAND (arg0
, 0);
2435 left
= TREE_OPERAND (arg0
, 1);
2436 right
= TREE_OPERAND (arg1
, 0);
2438 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2440 common
= TREE_OPERAND (arg0
, 1);
2441 left
= TREE_OPERAND (arg0
, 0);
2442 right
= TREE_OPERAND (arg1
, 1);
2444 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2446 common
= TREE_OPERAND (arg0
, 1);
2447 left
= TREE_OPERAND (arg0
, 0);
2448 right
= TREE_OPERAND (arg1
, 0);
2453 return fold (build (TREE_CODE (arg0
), type
, common
,
2454 fold (build (code
, type
, left
, right
))));
2457 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2458 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2461 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2464 int bitsize
, bitpos
;
2467 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2468 size_int (bitsize
), bitsize_int (bitpos
));
2470 TREE_UNSIGNED (result
) = unsignedp
;
2475 /* Optimize a bit-field compare.
2477 There are two cases: First is a compare against a constant and the
2478 second is a comparison of two items where the fields are at the same
2479 bit position relative to the start of a chunk (byte, halfword, word)
2480 large enough to contain it. In these cases we can avoid the shift
2481 implicit in bitfield extractions.
2483 For constants, we emit a compare of the shifted constant with the
2484 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2485 compared. For two fields at the same position, we do the ANDs with the
2486 similar mask and compare the result of the ANDs.
2488 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2489 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2490 are the left and right operands of the comparison, respectively.
2492 If the optimization described above can be done, we return the resulting
2493 tree. Otherwise we return zero. */
2496 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
2497 enum tree_code code
;
2501 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2502 tree type
= TREE_TYPE (lhs
);
2503 tree signed_type
, unsigned_type
;
2504 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2505 enum machine_mode lmode
, rmode
, nmode
;
2506 int lunsignedp
, runsignedp
;
2507 int lvolatilep
= 0, rvolatilep
= 0;
2508 tree linner
, rinner
= NULL_TREE
;
2512 /* Get all the information about the extractions being done. If the bit size
2513 if the same as the size of the underlying object, we aren't doing an
2514 extraction at all and so can do nothing. We also don't want to
2515 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2516 then will no longer be able to replace it. */
2517 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2518 &lunsignedp
, &lvolatilep
);
2519 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2520 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2525 /* If this is not a constant, we can only do something if bit positions,
2526 sizes, and signedness are the same. */
2527 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2528 &runsignedp
, &rvolatilep
);
2530 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2531 || lunsignedp
!= runsignedp
|| offset
!= 0
2532 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2536 /* See if we can find a mode to refer to this field. We should be able to,
2537 but fail if we can't. */
2538 nmode
= get_best_mode (lbitsize
, lbitpos
,
2539 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2540 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2541 TYPE_ALIGN (TREE_TYPE (rinner
))),
2542 word_mode
, lvolatilep
|| rvolatilep
);
2543 if (nmode
== VOIDmode
)
2546 /* Set signed and unsigned types of the precision of this mode for the
2548 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2549 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2551 /* Compute the bit position and size for the new reference and our offset
2552 within it. If the new reference is the same size as the original, we
2553 won't optimize anything, so return zero. */
2554 nbitsize
= GET_MODE_BITSIZE (nmode
);
2555 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2557 if (nbitsize
== lbitsize
)
2560 if (BYTES_BIG_ENDIAN
)
2561 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2563 /* Make the mask to be used against the extracted field. */
2564 mask
= build_int_2 (~0, ~0);
2565 TREE_TYPE (mask
) = unsigned_type
;
2566 force_fit_type (mask
, 0);
2567 mask
= convert (unsigned_type
, mask
);
2568 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2569 mask
= const_binop (RSHIFT_EXPR
, mask
,
2570 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2573 /* If not comparing with constant, just rework the comparison
2575 return build (code
, compare_type
,
2576 build (BIT_AND_EXPR
, unsigned_type
,
2577 make_bit_field_ref (linner
, unsigned_type
,
2578 nbitsize
, nbitpos
, 1),
2580 build (BIT_AND_EXPR
, unsigned_type
,
2581 make_bit_field_ref (rinner
, unsigned_type
,
2582 nbitsize
, nbitpos
, 1),
2585 /* Otherwise, we are handling the constant case. See if the constant is too
2586 big for the field. Warn and return a tree of for 0 (false) if so. We do
2587 this not only for its own sake, but to avoid having to test for this
2588 error case below. If we didn't, we might generate wrong code.
2590 For unsigned fields, the constant shifted right by the field length should
2591 be all zero. For signed fields, the high-order bits should agree with
2596 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2597 convert (unsigned_type
, rhs
),
2598 size_int (lbitsize
), 0)))
2600 warning ("comparison is always %d due to width of bit-field",
2602 return convert (compare_type
,
2604 ? integer_one_node
: integer_zero_node
));
2609 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2610 size_int (lbitsize
- 1), 0);
2611 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2613 warning ("comparison is always %d due to width of bit-field",
2615 return convert (compare_type
,
2617 ? integer_one_node
: integer_zero_node
));
2621 /* Single-bit compares should always be against zero. */
2622 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2624 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2625 rhs
= convert (type
, integer_zero_node
);
2628 /* Make a new bitfield reference, shift the constant over the
2629 appropriate number of bits and mask it with the computed mask
2630 (in case this was a signed field). If we changed it, make a new one. */
2631 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2634 TREE_SIDE_EFFECTS (lhs
) = 1;
2635 TREE_THIS_VOLATILE (lhs
) = 1;
2638 rhs
= fold (const_binop (BIT_AND_EXPR
,
2639 const_binop (LSHIFT_EXPR
,
2640 convert (unsigned_type
, rhs
),
2641 size_int (lbitpos
), 0),
2644 return build (code
, compare_type
,
2645 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2649 /* Subroutine for fold_truthop: decode a field reference.
2651 If EXP is a comparison reference, we return the innermost reference.
2653 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2654 set to the starting bit number.
2656 If the innermost field can be completely contained in a mode-sized
2657 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2659 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2660 otherwise it is not changed.
2662 *PUNSIGNEDP is set to the signedness of the field.
2664 *PMASK is set to the mask used. This is either contained in a
2665 BIT_AND_EXPR or derived from the width of the field.
2667 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2669 Return 0 if this is not a component reference or is one that we can't
2670 do anything with. */
2673 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
2674 pvolatilep
, pmask
, pand_mask
)
2676 HOST_WIDE_INT
*pbitsize
, *pbitpos
;
2677 enum machine_mode
*pmode
;
2678 int *punsignedp
, *pvolatilep
;
2683 tree mask
, inner
, offset
;
2685 unsigned int precision
;
2687 /* All the optimizations using this function assume integer fields.
2688 There are problems with FP fields since the type_for_size call
2689 below can fail for, e.g., XFmode. */
2690 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
2695 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
2697 and_mask
= TREE_OPERAND (exp
, 1);
2698 exp
= TREE_OPERAND (exp
, 0);
2699 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
2700 if (TREE_CODE (and_mask
) != INTEGER_CST
)
2704 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
2705 punsignedp
, pvolatilep
);
2706 if ((inner
== exp
&& and_mask
== 0)
2707 || *pbitsize
< 0 || offset
!= 0
2708 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
2711 /* Compute the mask to access the bitfield. */
2712 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
2713 precision
= TYPE_PRECISION (unsigned_type
);
2715 mask
= build_int_2 (~0, ~0);
2716 TREE_TYPE (mask
) = unsigned_type
;
2717 force_fit_type (mask
, 0);
2718 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2719 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2721 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2723 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
2724 convert (unsigned_type
, and_mask
), mask
));
2727 *pand_mask
= and_mask
;
2731 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2735 all_ones_mask_p (mask
, size
)
2739 tree type
= TREE_TYPE (mask
);
2740 unsigned int precision
= TYPE_PRECISION (type
);
2743 tmask
= build_int_2 (~0, ~0);
2744 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
2745 force_fit_type (tmask
, 0);
2747 tree_int_cst_equal (mask
,
2748 const_binop (RSHIFT_EXPR
,
2749 const_binop (LSHIFT_EXPR
, tmask
,
2750 size_int (precision
- size
),
2752 size_int (precision
- size
), 0));
2755 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2756 represents the sign bit of EXP's type. If EXP represents a sign
2757 or zero extension, also test VAL against the unextended type.
2758 The return value is the (sub)expression whose sign bit is VAL,
2759 or NULL_TREE otherwise. */
2762 sign_bit_p (exp
, val
)
2766 unsigned HOST_WIDE_INT lo
;
2771 /* Tree EXP must have an integral type. */
2772 t
= TREE_TYPE (exp
);
2773 if (! INTEGRAL_TYPE_P (t
))
2776 /* Tree VAL must be an integer constant. */
2777 if (TREE_CODE (val
) != INTEGER_CST
2778 || TREE_CONSTANT_OVERFLOW (val
))
2781 width
= TYPE_PRECISION (t
);
2782 if (width
> HOST_BITS_PER_WIDE_INT
)
2784 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
2790 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
2793 if (TREE_INT_CST_HIGH (val
) == hi
&& TREE_INT_CST_LOW (val
) == lo
)
2796 /* Handle extension from a narrower type. */
2797 if (TREE_CODE (exp
) == NOP_EXPR
2798 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
2799 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
2804 /* Subroutine for fold_truthop: determine if an operand is simple enough
2805 to be evaluated unconditionally. */
2808 simple_operand_p (exp
)
2811 /* Strip any conversions that don't change the machine mode. */
2812 while ((TREE_CODE (exp
) == NOP_EXPR
2813 || TREE_CODE (exp
) == CONVERT_EXPR
)
2814 && (TYPE_MODE (TREE_TYPE (exp
))
2815 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
2816 exp
= TREE_OPERAND (exp
, 0);
2818 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
2820 && ! TREE_ADDRESSABLE (exp
)
2821 && ! TREE_THIS_VOLATILE (exp
)
2822 && ! DECL_NONLOCAL (exp
)
2823 /* Don't regard global variables as simple. They may be
2824 allocated in ways unknown to the compiler (shared memory,
2825 #pragma weak, etc). */
2826 && ! TREE_PUBLIC (exp
)
2827 && ! DECL_EXTERNAL (exp
)
2828 /* Loading a static variable is unduly expensive, but global
2829 registers aren't expensive. */
2830 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
2833 /* The following functions are subroutines to fold_range_test and allow it to
2834 try to change a logical combination of comparisons into a range test.
2837 X == 2 || X == 3 || X == 4 || X == 5
2841 (unsigned) (X - 2) <= 3
2843 We describe each set of comparisons as being either inside or outside
2844 a range, using a variable named like IN_P, and then describe the
2845 range with a lower and upper bound. If one of the bounds is omitted,
2846 it represents either the highest or lowest value of the type.
2848 In the comments below, we represent a range by two numbers in brackets
2849 preceded by a "+" to designate being inside that range, or a "-" to
2850 designate being outside that range, so the condition can be inverted by
2851 flipping the prefix. An omitted bound is represented by a "-". For
2852 example, "- [-, 10]" means being outside the range starting at the lowest
2853 possible value and ending at 10, in other words, being greater than 10.
2854 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2857 We set up things so that the missing bounds are handled in a consistent
2858 manner so neither a missing bound nor "true" and "false" need to be
2859 handled using a special case. */
2861 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2862 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2863 and UPPER1_P are nonzero if the respective argument is an upper bound
2864 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2865 must be specified for a comparison. ARG1 will be converted to ARG0's
2866 type if both are specified. */
2869 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
2870 enum tree_code code
;
2873 int upper0_p
, upper1_p
;
2879 /* If neither arg represents infinity, do the normal operation.
2880 Else, if not a comparison, return infinity. Else handle the special
2881 comparison rules. Note that most of the cases below won't occur, but
2882 are handled for consistency. */
2884 if (arg0
!= 0 && arg1
!= 0)
2886 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
2887 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
2889 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
2892 if (TREE_CODE_CLASS (code
) != '<')
2895 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2896 for neither. In real maths, we cannot assume open ended ranges are
2897 the same. But, this is computer arithmetic, where numbers are finite.
2898 We can therefore make the transformation of any unbounded range with
2899 the value Z, Z being greater than any representable number. This permits
2900 us to treat unbounded ranges as equal. */
2901 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
2902 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
2906 result
= sgn0
== sgn1
;
2909 result
= sgn0
!= sgn1
;
2912 result
= sgn0
< sgn1
;
2915 result
= sgn0
<= sgn1
;
2918 result
= sgn0
> sgn1
;
2921 result
= sgn0
>= sgn1
;
2927 return convert (type
, result
? integer_one_node
: integer_zero_node
);
2930 /* Given EXP, a logical expression, set the range it is testing into
2931 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2932 actually being tested. *PLOW and *PHIGH will be made of the same type
2933 as the returned expression. If EXP is not a comparison, we will most
2934 likely not be returning a useful value and range. */
2937 make_range (exp
, pin_p
, plow
, phigh
)
2942 enum tree_code code
;
2943 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
2944 tree orig_type
= NULL_TREE
;
2946 tree low
, high
, n_low
, n_high
;
2948 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2949 and see if we can refine the range. Some of the cases below may not
2950 happen, but it doesn't seem worth worrying about this. We "continue"
2951 the outer loop when we've changed something; otherwise we "break"
2952 the switch, which will "break" the while. */
2954 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
2958 code
= TREE_CODE (exp
);
2960 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
2962 arg0
= TREE_OPERAND (exp
, 0);
2963 if (TREE_CODE_CLASS (code
) == '<'
2964 || TREE_CODE_CLASS (code
) == '1'
2965 || TREE_CODE_CLASS (code
) == '2')
2966 type
= TREE_TYPE (arg0
);
2967 if (TREE_CODE_CLASS (code
) == '2'
2968 || TREE_CODE_CLASS (code
) == '<'
2969 || (TREE_CODE_CLASS (code
) == 'e'
2970 && TREE_CODE_LENGTH (code
) > 1))
2971 arg1
= TREE_OPERAND (exp
, 1);
2974 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2975 lose a cast by accident. */
2976 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
2981 case TRUTH_NOT_EXPR
:
2982 in_p
= ! in_p
, exp
= arg0
;
2985 case EQ_EXPR
: case NE_EXPR
:
2986 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
2987 /* We can only do something if the range is testing for zero
2988 and if the second operand is an integer constant. Note that
2989 saying something is "in" the range we make is done by
2990 complementing IN_P since it will set in the initial case of
2991 being not equal to zero; "out" is leaving it alone. */
2992 if (low
== 0 || high
== 0
2993 || ! integer_zerop (low
) || ! integer_zerop (high
)
2994 || TREE_CODE (arg1
) != INTEGER_CST
)
2999 case NE_EXPR
: /* - [c, c] */
3002 case EQ_EXPR
: /* + [c, c] */
3003 in_p
= ! in_p
, low
= high
= arg1
;
3005 case GT_EXPR
: /* - [-, c] */
3006 low
= 0, high
= arg1
;
3008 case GE_EXPR
: /* + [c, -] */
3009 in_p
= ! in_p
, low
= arg1
, high
= 0;
3011 case LT_EXPR
: /* - [c, -] */
3012 low
= arg1
, high
= 0;
3014 case LE_EXPR
: /* + [-, c] */
3015 in_p
= ! in_p
, low
= 0, high
= arg1
;
3023 /* If this is an unsigned comparison, we also know that EXP is
3024 greater than or equal to zero. We base the range tests we make
3025 on that fact, so we record it here so we can parse existing
3027 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3029 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3030 1, convert (type
, integer_zero_node
),
3034 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3036 /* If the high bound is missing, but we
3037 have a low bound, reverse the range so
3038 it goes from zero to the low bound minus 1. */
3039 if (high
== 0 && low
)
3042 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3043 integer_one_node
, 0);
3044 low
= convert (type
, integer_zero_node
);
3050 /* (-x) IN [a,b] -> x in [-b, -a] */
3051 n_low
= range_binop (MINUS_EXPR
, type
,
3052 convert (type
, integer_zero_node
), 0, high
, 1);
3053 n_high
= range_binop (MINUS_EXPR
, type
,
3054 convert (type
, integer_zero_node
), 0, low
, 0);
3055 low
= n_low
, high
= n_high
;
3061 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3062 convert (type
, integer_one_node
));
3065 case PLUS_EXPR
: case MINUS_EXPR
:
3066 if (TREE_CODE (arg1
) != INTEGER_CST
)
3069 /* If EXP is signed, any overflow in the computation is undefined,
3070 so we don't worry about it so long as our computations on
3071 the bounds don't overflow. For unsigned, overflow is defined
3072 and this is exactly the right thing. */
3073 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3074 type
, low
, 0, arg1
, 0);
3075 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3076 type
, high
, 1, arg1
, 0);
3077 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3078 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3081 /* Check for an unsigned range which has wrapped around the maximum
3082 value thus making n_high < n_low, and normalize it. */
3083 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3085 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3086 integer_one_node
, 0);
3087 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3088 integer_one_node
, 0);
3090 /* If the range is of the form +/- [ x+1, x ], we won't
3091 be able to normalize it. But then, it represents the
3092 whole range or the empty set, so make it
3094 if (tree_int_cst_equal (n_low
, low
)
3095 && tree_int_cst_equal (n_high
, high
))
3101 low
= n_low
, high
= n_high
;
3106 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3107 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3110 if (! INTEGRAL_TYPE_P (type
)
3111 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3112 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3115 n_low
= low
, n_high
= high
;
3118 n_low
= convert (type
, n_low
);
3121 n_high
= convert (type
, n_high
);
3123 /* If we're converting from an unsigned to a signed type,
3124 we will be doing the comparison as unsigned. The tests above
3125 have already verified that LOW and HIGH are both positive.
3127 So we have to make sure that the original unsigned value will
3128 be interpreted as positive. */
3129 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3131 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3132 (TYPE_MODE (type
), 1);
3135 /* A range without an upper bound is, naturally, unbounded.
3136 Since convert would have cropped a very large value, use
3137 the max value for the destination type. */
3139 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3140 : TYPE_MAX_VALUE (type
);
3142 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3143 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3144 convert (type
, high_positive
),
3145 convert (type
, integer_one_node
)));
3147 /* If the low bound is specified, "and" the range with the
3148 range for which the original unsigned value will be
3152 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3154 1, convert (type
, integer_zero_node
),
3158 in_p
= (n_in_p
== in_p
);
3162 /* Otherwise, "or" the range with the range of the input
3163 that will be interpreted as negative. */
3164 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3166 1, convert (type
, integer_zero_node
),
3170 in_p
= (in_p
!= n_in_p
);
3175 low
= n_low
, high
= n_high
;
3185 /* If EXP is a constant, we can evaluate whether this is true or false. */
3186 if (TREE_CODE (exp
) == INTEGER_CST
)
3188 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3190 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3196 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3200 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3201 type, TYPE, return an expression to test if EXP is in (or out of, depending
3202 on IN_P) the range. */
3205 build_range_check (type
, exp
, in_p
, low
, high
)
3211 tree etype
= TREE_TYPE (exp
);
3215 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3216 return invert_truthvalue (value
);
3218 if (low
== 0 && high
== 0)
3219 return convert (type
, integer_one_node
);
3222 return fold (build (LE_EXPR
, type
, exp
, high
));
3225 return fold (build (GE_EXPR
, type
, exp
, low
));
3227 if (operand_equal_p (low
, high
, 0))
3228 return fold (build (EQ_EXPR
, type
, exp
, low
));
3230 if (integer_zerop (low
))
3232 if (! TREE_UNSIGNED (etype
))
3234 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3235 high
= convert (etype
, high
);
3236 exp
= convert (etype
, exp
);
3238 return build_range_check (type
, exp
, 1, 0, high
);
3241 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3242 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3244 unsigned HOST_WIDE_INT lo
;
3248 prec
= TYPE_PRECISION (etype
);
3249 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3252 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3256 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3257 lo
= (unsigned HOST_WIDE_INT
) -1;
3260 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3262 if (TREE_UNSIGNED (etype
))
3264 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3265 exp
= convert (etype
, exp
);
3267 return fold (build (GT_EXPR
, type
, exp
,
3268 convert (etype
, integer_zero_node
)));
3272 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3273 && ! TREE_OVERFLOW (value
))
3274 return build_range_check (type
,
3275 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3276 1, convert (etype
, integer_zero_node
), value
);
3281 /* Given two ranges, see if we can merge them into one. Return 1 if we
3282 can, 0 if we can't. Set the output range into the specified parameters. */
3285 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3289 tree low0
, high0
, low1
, high1
;
3297 int lowequal
= ((low0
== 0 && low1
== 0)
3298 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3299 low0
, 0, low1
, 0)));
3300 int highequal
= ((high0
== 0 && high1
== 0)
3301 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3302 high0
, 1, high1
, 1)));
3304 /* Make range 0 be the range that starts first, or ends last if they
3305 start at the same value. Swap them if it isn't. */
3306 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3309 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3310 high1
, 1, high0
, 1))))
3312 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3313 tem
= low0
, low0
= low1
, low1
= tem
;
3314 tem
= high0
, high0
= high1
, high1
= tem
;
3317 /* Now flag two cases, whether the ranges are disjoint or whether the
3318 second range is totally subsumed in the first. Note that the tests
3319 below are simplified by the ones above. */
3320 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3321 high0
, 1, low1
, 0));
3322 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3323 high1
, 1, high0
, 1));
3325 /* We now have four cases, depending on whether we are including or
3326 excluding the two ranges. */
3329 /* If they don't overlap, the result is false. If the second range
3330 is a subset it is the result. Otherwise, the range is from the start
3331 of the second to the end of the first. */
3333 in_p
= 0, low
= high
= 0;
3335 in_p
= 1, low
= low1
, high
= high1
;
3337 in_p
= 1, low
= low1
, high
= high0
;
3340 else if (in0_p
&& ! in1_p
)
3342 /* If they don't overlap, the result is the first range. If they are
3343 equal, the result is false. If the second range is a subset of the
3344 first, and the ranges begin at the same place, we go from just after
3345 the end of the first range to the end of the second. If the second
3346 range is not a subset of the first, or if it is a subset and both
3347 ranges end at the same place, the range starts at the start of the
3348 first range and ends just before the second range.
3349 Otherwise, we can't describe this as a single range. */
3351 in_p
= 1, low
= low0
, high
= high0
;
3352 else if (lowequal
&& highequal
)
3353 in_p
= 0, low
= high
= 0;
3354 else if (subset
&& lowequal
)
3356 in_p
= 1, high
= high0
;
3357 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3358 integer_one_node
, 0);
3360 else if (! subset
|| highequal
)
3362 in_p
= 1, low
= low0
;
3363 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3364 integer_one_node
, 0);
3370 else if (! in0_p
&& in1_p
)
3372 /* If they don't overlap, the result is the second range. If the second
3373 is a subset of the first, the result is false. Otherwise,
3374 the range starts just after the first range and ends at the
3375 end of the second. */
3377 in_p
= 1, low
= low1
, high
= high1
;
3378 else if (subset
|| highequal
)
3379 in_p
= 0, low
= high
= 0;
3382 in_p
= 1, high
= high1
;
3383 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3384 integer_one_node
, 0);
3390 /* The case where we are excluding both ranges. Here the complex case
3391 is if they don't overlap. In that case, the only time we have a
3392 range is if they are adjacent. If the second is a subset of the
3393 first, the result is the first. Otherwise, the range to exclude
3394 starts at the beginning of the first range and ends at the end of the
3398 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3399 range_binop (PLUS_EXPR
, NULL_TREE
,
3401 integer_one_node
, 1),
3403 in_p
= 0, low
= low0
, high
= high1
;
3408 in_p
= 0, low
= low0
, high
= high0
;
3410 in_p
= 0, low
= low0
, high
= high1
;
3413 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3417 #ifndef RANGE_TEST_NON_SHORT_CIRCUIT
3418 #define RANGE_TEST_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
3421 /* EXP is some logical combination of boolean tests. See if we can
3422 merge it into some range test. Return the new tree if so. */
3425 fold_range_test (exp
)
3428 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3429 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3430 int in0_p
, in1_p
, in_p
;
3431 tree low0
, low1
, low
, high0
, high1
, high
;
3432 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3433 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3436 /* If this is an OR operation, invert both sides; we will invert
3437 again at the end. */
3439 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3441 /* If both expressions are the same, if we can merge the ranges, and we
3442 can build the range test, return it or it inverted. If one of the
3443 ranges is always true or always false, consider it to be the same
3444 expression as the other. */
3445 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3446 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3448 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3450 : rhs
!= 0 ? rhs
: integer_zero_node
,
3452 return or_op
? invert_truthvalue (tem
) : tem
;
3454 /* On machines where the branch cost is expensive, if this is a
3455 short-circuited branch and the underlying object on both sides
3456 is the same, make a non-short-circuit operation. */
3457 else if (RANGE_TEST_NON_SHORT_CIRCUIT
3458 && lhs
!= 0 && rhs
!= 0
3459 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3460 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3461 && operand_equal_p (lhs
, rhs
, 0))
3463 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3464 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3465 which cases we can't do this. */
3466 if (simple_operand_p (lhs
))
3467 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3468 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3469 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3470 TREE_OPERAND (exp
, 1));
3472 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3473 && ! CONTAINS_PLACEHOLDER_P (lhs
))
3475 tree common
= save_expr (lhs
);
3477 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3478 or_op
? ! in0_p
: in0_p
,
3480 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3481 or_op
? ! in1_p
: in1_p
,
3483 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3484 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3485 TREE_TYPE (exp
), lhs
, rhs
);
3492 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3493 bit value. Arrange things so the extra bits will be set to zero if and
3494 only if C is signed-extended to its full width. If MASK is nonzero,
3495 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3498 unextend (c
, p
, unsignedp
, mask
)
3504 tree type
= TREE_TYPE (c
);
3505 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3508 if (p
== modesize
|| unsignedp
)
3511 /* We work by getting just the sign bit into the low-order bit, then
3512 into the high-order bit, then sign-extend. We then XOR that value
3514 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3515 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3517 /* We must use a signed type in order to get an arithmetic right shift.
3518 However, we must also avoid introducing accidental overflows, so that
3519 a subsequent call to integer_zerop will work. Hence we must
3520 do the type conversion here. At this point, the constant is either
3521 zero or one, and the conversion to a signed type can never overflow.
3522 We could get an overflow if this conversion is done anywhere else. */
3523 if (TREE_UNSIGNED (type
))
3524 temp
= convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3526 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3527 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3529 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3530 /* If necessary, convert the type back to match the type of C. */
3531 if (TREE_UNSIGNED (type
))
3532 temp
= convert (type
, temp
);
3534 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3537 /* Find ways of folding logical expressions of LHS and RHS:
3538 Try to merge two comparisons to the same innermost item.
3539 Look for range tests like "ch >= '0' && ch <= '9'".
3540 Look for combinations of simple terms on machines with expensive branches
3541 and evaluate the RHS unconditionally.
3543 For example, if we have p->a == 2 && p->b == 4 and we can make an
3544 object large enough to span both A and B, we can do this with a comparison
3545 against the object ANDed with the a mask.
3547 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3548 operations to do this with one comparison.
3550 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3551 function and the one above.
3553 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3554 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3556 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3559 We return the simplified tree or 0 if no optimization is possible. */
3562 fold_truthop (code
, truth_type
, lhs
, rhs
)
3563 enum tree_code code
;
3564 tree truth_type
, lhs
, rhs
;
3566 /* If this is the "or" of two comparisons, we can do something if
3567 the comparisons are NE_EXPR. If this is the "and", we can do something
3568 if the comparisons are EQ_EXPR. I.e.,
3569 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3571 WANTED_CODE is this operation code. For single bit fields, we can
3572 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3573 comparison for one-bit fields. */
3575 enum tree_code wanted_code
;
3576 enum tree_code lcode
, rcode
;
3577 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3578 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3579 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3580 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3581 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3582 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3583 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3584 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3585 enum machine_mode lnmode
, rnmode
;
3586 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3587 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3588 tree l_const
, r_const
;
3589 tree lntype
, rntype
, result
;
3590 int first_bit
, end_bit
;
3593 /* Start by getting the comparison codes. Fail if anything is volatile.
3594 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3595 it were surrounded with a NE_EXPR. */
3597 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3600 lcode
= TREE_CODE (lhs
);
3601 rcode
= TREE_CODE (rhs
);
3603 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3604 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3606 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3607 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3609 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3612 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3613 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3615 ll_arg
= TREE_OPERAND (lhs
, 0);
3616 lr_arg
= TREE_OPERAND (lhs
, 1);
3617 rl_arg
= TREE_OPERAND (rhs
, 0);
3618 rr_arg
= TREE_OPERAND (rhs
, 1);
3620 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3621 if (simple_operand_p (ll_arg
)
3622 && simple_operand_p (lr_arg
)
3623 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3627 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3628 && operand_equal_p (lr_arg
, rr_arg
, 0))
3630 int lcompcode
, rcompcode
;
3632 lcompcode
= comparison_to_compcode (lcode
);
3633 rcompcode
= comparison_to_compcode (rcode
);
3634 compcode
= (code
== TRUTH_AND_EXPR
)
3635 ? lcompcode
& rcompcode
3636 : lcompcode
| rcompcode
;
3638 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3639 && operand_equal_p (lr_arg
, rl_arg
, 0))
3641 int lcompcode
, rcompcode
;
3643 rcode
= swap_tree_comparison (rcode
);
3644 lcompcode
= comparison_to_compcode (lcode
);
3645 rcompcode
= comparison_to_compcode (rcode
);
3646 compcode
= (code
== TRUTH_AND_EXPR
)
3647 ? lcompcode
& rcompcode
3648 : lcompcode
| rcompcode
;
3653 if (compcode
== COMPCODE_TRUE
)
3654 return convert (truth_type
, integer_one_node
);
3655 else if (compcode
== COMPCODE_FALSE
)
3656 return convert (truth_type
, integer_zero_node
);
3657 else if (compcode
!= -1)
3658 return build (compcode_to_comparison (compcode
),
3659 truth_type
, ll_arg
, lr_arg
);
3662 /* If the RHS can be evaluated unconditionally and its operands are
3663 simple, it wins to evaluate the RHS unconditionally on machines
3664 with expensive branches. In this case, this isn't a comparison
3665 that can be merged. Avoid doing this if the RHS is a floating-point
3666 comparison since those can trap. */
3668 if (BRANCH_COST
>= 2
3669 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3670 && simple_operand_p (rl_arg
)
3671 && simple_operand_p (rr_arg
))
3673 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3674 if (code
== TRUTH_OR_EXPR
3675 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
3676 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
3677 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3678 return build (NE_EXPR
, truth_type
,
3679 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3683 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3684 if (code
== TRUTH_AND_EXPR
3685 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
3686 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
3687 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3688 return build (EQ_EXPR
, truth_type
,
3689 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3693 return build (code
, truth_type
, lhs
, rhs
);
3696 /* See if the comparisons can be merged. Then get all the parameters for
3699 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3700 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3704 ll_inner
= decode_field_reference (ll_arg
,
3705 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3706 &ll_unsignedp
, &volatilep
, &ll_mask
,
3708 lr_inner
= decode_field_reference (lr_arg
,
3709 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3710 &lr_unsignedp
, &volatilep
, &lr_mask
,
3712 rl_inner
= decode_field_reference (rl_arg
,
3713 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3714 &rl_unsignedp
, &volatilep
, &rl_mask
,
3716 rr_inner
= decode_field_reference (rr_arg
,
3717 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3718 &rr_unsignedp
, &volatilep
, &rr_mask
,
3721 /* It must be true that the inner operation on the lhs of each
3722 comparison must be the same if we are to be able to do anything.
3723 Then see if we have constants. If not, the same must be true for
3725 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3726 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3729 if (TREE_CODE (lr_arg
) == INTEGER_CST
3730 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3731 l_const
= lr_arg
, r_const
= rr_arg
;
3732 else if (lr_inner
== 0 || rr_inner
== 0
3733 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3736 l_const
= r_const
= 0;
3738 /* If either comparison code is not correct for our logical operation,
3739 fail. However, we can convert a one-bit comparison against zero into
3740 the opposite comparison against that bit being set in the field. */
3742 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3743 if (lcode
!= wanted_code
)
3745 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3747 /* Make the left operand unsigned, since we are only interested
3748 in the value of one bit. Otherwise we are doing the wrong
3757 /* This is analogous to the code for l_const above. */
3758 if (rcode
!= wanted_code
)
3760 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3769 /* After this point all optimizations will generate bit-field
3770 references, which we might not want. */
3771 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
3774 /* See if we can find a mode that contains both fields being compared on
3775 the left. If we can't, fail. Otherwise, update all constants and masks
3776 to be relative to a field of that size. */
3777 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3778 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3779 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3780 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3782 if (lnmode
== VOIDmode
)
3785 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3786 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3787 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
3788 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3790 if (BYTES_BIG_ENDIAN
)
3792 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3793 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3796 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3797 size_int (xll_bitpos
), 0);
3798 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3799 size_int (xrl_bitpos
), 0);
3803 l_const
= convert (lntype
, l_const
);
3804 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3805 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3806 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3807 fold (build1 (BIT_NOT_EXPR
,
3811 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3813 return convert (truth_type
,
3814 wanted_code
== NE_EXPR
3815 ? integer_one_node
: integer_zero_node
);
3820 r_const
= convert (lntype
, r_const
);
3821 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3822 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3823 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3824 fold (build1 (BIT_NOT_EXPR
,
3828 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3830 return convert (truth_type
,
3831 wanted_code
== NE_EXPR
3832 ? integer_one_node
: integer_zero_node
);
3836 /* If the right sides are not constant, do the same for it. Also,
3837 disallow this optimization if a size or signedness mismatch occurs
3838 between the left and right sides. */
3841 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
3842 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
3843 /* Make sure the two fields on the right
3844 correspond to the left without being swapped. */
3845 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
3848 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
3849 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
3850 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3851 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
3853 if (rnmode
== VOIDmode
)
3856 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
3857 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
3858 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
3859 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
3861 if (BYTES_BIG_ENDIAN
)
3863 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
3864 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
3867 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
3868 size_int (xlr_bitpos
), 0);
3869 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
3870 size_int (xrr_bitpos
), 0);
3872 /* Make a mask that corresponds to both fields being compared.
3873 Do this for both items being compared. If the operands are the
3874 same size and the bits being compared are in the same position
3875 then we can do this by masking both and comparing the masked
3877 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3878 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
3879 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
3881 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3882 ll_unsignedp
|| rl_unsignedp
);
3883 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3884 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
3886 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
3887 lr_unsignedp
|| rr_unsignedp
);
3888 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
3889 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
3891 return build (wanted_code
, truth_type
, lhs
, rhs
);
3894 /* There is still another way we can do something: If both pairs of
3895 fields being compared are adjacent, we may be able to make a wider
3896 field containing them both.
3898 Note that we still must mask the lhs/rhs expressions. Furthermore,
3899 the mask must be shifted to account for the shift done by
3900 make_bit_field_ref. */
3901 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
3902 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
3903 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
3904 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
3908 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
3909 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
3910 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
3911 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
3913 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
3914 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
3915 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
3916 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
3918 /* Convert to the smaller type before masking out unwanted bits. */
3920 if (lntype
!= rntype
)
3922 if (lnbitsize
> rnbitsize
)
3924 lhs
= convert (rntype
, lhs
);
3925 ll_mask
= convert (rntype
, ll_mask
);
3928 else if (lnbitsize
< rnbitsize
)
3930 rhs
= convert (lntype
, rhs
);
3931 lr_mask
= convert (lntype
, lr_mask
);
3936 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
3937 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
3939 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
3940 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
3942 return build (wanted_code
, truth_type
, lhs
, rhs
);
3948 /* Handle the case of comparisons with constants. If there is something in
3949 common between the masks, those bits of the constants must be the same.
3950 If not, the condition is always false. Test for this to avoid generating
3951 incorrect code below. */
3952 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
3953 if (! integer_zerop (result
)
3954 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
3955 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
3957 if (wanted_code
== NE_EXPR
)
3959 warning ("`or' of unmatched not-equal tests is always 1");
3960 return convert (truth_type
, integer_one_node
);
3964 warning ("`and' of mutually exclusive equal-tests is always 0");
3965 return convert (truth_type
, integer_zero_node
);
3969 /* Construct the expression we will return. First get the component
3970 reference we will make. Unless the mask is all ones the width of
3971 that field, perform the mask operation. Then compare with the
3973 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3974 ll_unsignedp
|| rl_unsignedp
);
3976 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3977 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3978 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
3980 return build (wanted_code
, truth_type
, result
,
3981 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
3984 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3988 optimize_minmax_comparison (t
)
3991 tree type
= TREE_TYPE (t
);
3992 tree arg0
= TREE_OPERAND (t
, 0);
3993 enum tree_code op_code
;
3994 tree comp_const
= TREE_OPERAND (t
, 1);
3996 int consts_equal
, consts_lt
;
3999 STRIP_SIGN_NOPS (arg0
);
4001 op_code
= TREE_CODE (arg0
);
4002 minmax_const
= TREE_OPERAND (arg0
, 1);
4003 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
4004 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
4005 inner
= TREE_OPERAND (arg0
, 0);
4007 /* If something does not permit us to optimize, return the original tree. */
4008 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4009 || TREE_CODE (comp_const
) != INTEGER_CST
4010 || TREE_CONSTANT_OVERFLOW (comp_const
)
4011 || TREE_CODE (minmax_const
) != INTEGER_CST
4012 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4015 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4016 and GT_EXPR, doing the rest with recursive calls using logical
4018 switch (TREE_CODE (t
))
4020 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4022 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4026 fold (build (TRUTH_ORIF_EXPR
, type
,
4027 optimize_minmax_comparison
4028 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4029 optimize_minmax_comparison
4030 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4033 if (op_code
== MAX_EXPR
&& consts_equal
)
4034 /* MAX (X, 0) == 0 -> X <= 0 */
4035 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4037 else if (op_code
== MAX_EXPR
&& consts_lt
)
4038 /* MAX (X, 0) == 5 -> X == 5 */
4039 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4041 else if (op_code
== MAX_EXPR
)
4042 /* MAX (X, 0) == -1 -> false */
4043 return omit_one_operand (type
, integer_zero_node
, inner
);
4045 else if (consts_equal
)
4046 /* MIN (X, 0) == 0 -> X >= 0 */
4047 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4050 /* MIN (X, 0) == 5 -> false */
4051 return omit_one_operand (type
, integer_zero_node
, inner
);
4054 /* MIN (X, 0) == -1 -> X == -1 */
4055 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4058 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4059 /* MAX (X, 0) > 0 -> X > 0
4060 MAX (X, 0) > 5 -> X > 5 */
4061 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4063 else if (op_code
== MAX_EXPR
)
4064 /* MAX (X, 0) > -1 -> true */
4065 return omit_one_operand (type
, integer_one_node
, inner
);
4067 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4068 /* MIN (X, 0) > 0 -> false
4069 MIN (X, 0) > 5 -> false */
4070 return omit_one_operand (type
, integer_zero_node
, inner
);
4073 /* MIN (X, 0) > -1 -> X > -1 */
4074 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4081 /* T is an integer expression that is being multiplied, divided, or taken a
4082 modulus (CODE says which and what kind of divide or modulus) by a
4083 constant C. See if we can eliminate that operation by folding it with
4084 other operations already in T. WIDE_TYPE, if non-null, is a type that
4085 should be used for the computation if wider than our type.
4087 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4088 (X * 2) + (Y * 4). We must, however, be assured that either the original
4089 expression would not overflow or that overflow is undefined for the type
4090 in the language in question.
4092 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4093 the machine has a multiply-accumulate insn or that this is part of an
4094 addressing calculation.
4096 If we return a non-null expression, it is an equivalent form of the
4097 original computation, but need not be in the original type. */
4100 extract_muldiv (t
, c
, code
, wide_type
)
4103 enum tree_code code
;
4106 /* To avoid exponential search depth, refuse to allow recursion past
4107 three levels. Beyond that (1) it's highly unlikely that we'll find
4108 something interesting and (2) we've probably processed it before
4109 when we built the inner expression. */
4118 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4125 extract_muldiv_1 (t
, c
, code
, wide_type
)
4128 enum tree_code code
;
4131 tree type
= TREE_TYPE (t
);
4132 enum tree_code tcode
= TREE_CODE (t
);
4133 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4134 > GET_MODE_SIZE (TYPE_MODE (type
)))
4135 ? wide_type
: type
);
4137 int same_p
= tcode
== code
;
4138 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4140 /* Don't deal with constants of zero here; they confuse the code below. */
4141 if (integer_zerop (c
))
4144 if (TREE_CODE_CLASS (tcode
) == '1')
4145 op0
= TREE_OPERAND (t
, 0);
4147 if (TREE_CODE_CLASS (tcode
) == '2')
4148 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4150 /* Note that we need not handle conditional operations here since fold
4151 already handles those cases. So just do arithmetic here. */
4155 /* For a constant, we can always simplify if we are a multiply
4156 or (for divide and modulus) if it is a multiple of our constant. */
4157 if (code
== MULT_EXPR
4158 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4159 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4162 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4163 /* If op0 is an expression ... */
4164 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4165 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4166 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4167 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4168 /* ... and is unsigned, and its type is smaller than ctype,
4169 then we cannot pass through as widening. */
4170 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4171 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4172 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4173 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4174 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4175 /* ... or its type is larger than ctype,
4176 then we cannot pass through this truncation. */
4177 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4178 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))
4179 /* ... or signedness changes for division or modulus,
4180 then we cannot pass through this conversion. */
4181 || (code
!= MULT_EXPR
4182 && (TREE_UNSIGNED (ctype
)
4183 != TREE_UNSIGNED (TREE_TYPE (op0
))))))
4186 /* Pass the constant down and see if we can make a simplification. If
4187 we can, replace this expression with the inner simplification for
4188 possible later conversion to our or some other type. */
4189 if ((t2
= convert (TREE_TYPE (op0
), c
)) != 0
4190 && TREE_CODE (t2
) == INTEGER_CST
4191 && ! TREE_CONSTANT_OVERFLOW (t2
)
4192 && (0 != (t1
= extract_muldiv (op0
, t2
, code
,
4194 ? ctype
: NULL_TREE
))))
4198 case NEGATE_EXPR
: case ABS_EXPR
:
4199 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4200 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4203 case MIN_EXPR
: case MAX_EXPR
:
4204 /* If widening the type changes the signedness, then we can't perform
4205 this optimization as that changes the result. */
4206 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4209 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4210 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4211 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4213 if (tree_int_cst_sgn (c
) < 0)
4214 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4216 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4217 convert (ctype
, t2
)));
4221 case WITH_RECORD_EXPR
:
4222 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4223 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4224 TREE_OPERAND (t
, 1));
4228 /* If this has not been evaluated and the operand has no side effects,
4229 we can see if we can do something inside it and make a new one.
4230 Note that this test is overly conservative since we can do this
4231 if the only reason it had side effects is that it was another
4232 similar SAVE_EXPR, but that isn't worth bothering with. */
4233 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4234 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4237 t1
= save_expr (t1
);
4238 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4239 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4240 if (is_pending_size (t
))
4241 put_pending_size (t1
);
4246 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4247 /* If the second operand is constant, this is a multiplication
4248 or floor division, by a power of two, so we can treat it that
4249 way unless the multiplier or divisor overflows. */
4250 if (TREE_CODE (op1
) == INTEGER_CST
4251 /* const_binop may not detect overflow correctly,
4252 so check for it explicitly here. */
4253 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4254 && TREE_INT_CST_HIGH (op1
) == 0
4255 && 0 != (t1
= convert (ctype
,
4256 const_binop (LSHIFT_EXPR
, size_one_node
,
4258 && ! TREE_OVERFLOW (t1
))
4259 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4260 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4261 ctype
, convert (ctype
, op0
), t1
),
4262 c
, code
, wide_type
);
4265 case PLUS_EXPR
: case MINUS_EXPR
:
4266 /* See if we can eliminate the operation on both sides. If we can, we
4267 can return a new PLUS or MINUS. If we can't, the only remaining
4268 cases where we can do anything are if the second operand is a
4270 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4271 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4272 if (t1
!= 0 && t2
!= 0
4273 && (code
== MULT_EXPR
4274 /* If not multiplication, we can only do this if both operands
4275 are divisible by c. */
4276 || (multiple_of_p (ctype
, op0
, c
)
4277 && multiple_of_p (ctype
, op1
, c
))))
4278 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4279 convert (ctype
, t2
)));
4281 /* If this was a subtraction, negate OP1 and set it to be an addition.
4282 This simplifies the logic below. */
4283 if (tcode
== MINUS_EXPR
)
4284 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4286 if (TREE_CODE (op1
) != INTEGER_CST
)
4289 /* If either OP1 or C are negative, this optimization is not safe for
4290 some of the division and remainder types while for others we need
4291 to change the code. */
4292 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4294 if (code
== CEIL_DIV_EXPR
)
4295 code
= FLOOR_DIV_EXPR
;
4296 else if (code
== FLOOR_DIV_EXPR
)
4297 code
= CEIL_DIV_EXPR
;
4298 else if (code
!= MULT_EXPR
4299 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4303 /* If it's a multiply or a division/modulus operation of a multiple
4304 of our constant, do the operation and verify it doesn't overflow. */
4305 if (code
== MULT_EXPR
4306 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4308 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4309 if (op1
== 0 || TREE_OVERFLOW (op1
))
4315 /* If we have an unsigned type is not a sizetype, we cannot widen
4316 the operation since it will change the result if the original
4317 computation overflowed. */
4318 if (TREE_UNSIGNED (ctype
)
4319 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4323 /* If we were able to eliminate our operation from the first side,
4324 apply our operation to the second side and reform the PLUS. */
4325 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4326 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4328 /* The last case is if we are a multiply. In that case, we can
4329 apply the distributive law to commute the multiply and addition
4330 if the multiplication of the constants doesn't overflow. */
4331 if (code
== MULT_EXPR
)
4332 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4333 convert (ctype
, op0
),
4334 convert (ctype
, c
))),
4340 /* We have a special case here if we are doing something like
4341 (C * 8) % 4 since we know that's zero. */
4342 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4343 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4344 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4345 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4346 return omit_one_operand (type
, integer_zero_node
, op0
);
4348 /* ... fall through ... */
4350 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4351 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4352 /* If we can extract our operation from the LHS, do so and return a
4353 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4354 do something only if the second operand is a constant. */
4356 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4357 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4358 convert (ctype
, op1
)));
4359 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4360 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4361 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4362 convert (ctype
, t1
)));
4363 else if (TREE_CODE (op1
) != INTEGER_CST
)
4366 /* If these are the same operation types, we can associate them
4367 assuming no overflow. */
4369 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4370 convert (ctype
, c
), 0))
4371 && ! TREE_OVERFLOW (t1
))
4372 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4374 /* If these operations "cancel" each other, we have the main
4375 optimizations of this pass, which occur when either constant is a
4376 multiple of the other, in which case we replace this with either an
4377 operation or CODE or TCODE.
4379 If we have an unsigned type that is not a sizetype, we cannot do
4380 this since it will change the result if the original computation
4382 if ((! TREE_UNSIGNED (ctype
)
4383 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4384 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4385 || (tcode
== MULT_EXPR
4386 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4387 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4389 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4390 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4392 const_binop (TRUNC_DIV_EXPR
,
4394 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4395 return fold (build (code
, ctype
, convert (ctype
, op0
),
4397 const_binop (TRUNC_DIV_EXPR
,
4409 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4410 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4411 that we may sometimes modify the tree. */
4414 strip_compound_expr (t
, s
)
4418 enum tree_code code
= TREE_CODE (t
);
4420 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4421 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4422 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4423 return TREE_OPERAND (t
, 1);
4425 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4426 don't bother handling any other types. */
4427 else if (code
== COND_EXPR
)
4429 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4430 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4431 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4433 else if (TREE_CODE_CLASS (code
) == '1')
4434 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4435 else if (TREE_CODE_CLASS (code
) == '<'
4436 || TREE_CODE_CLASS (code
) == '2')
4438 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4439 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4445 /* Return a node which has the indicated constant VALUE (either 0 or
4446 1), and is of the indicated TYPE. */
4449 constant_boolean_node (value
, type
)
4453 if (type
== integer_type_node
)
4454 return value
? integer_one_node
: integer_zero_node
;
4455 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4456 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4460 tree t
= build_int_2 (value
, 0);
4462 TREE_TYPE (t
) = type
;
4467 /* Utility function for the following routine, to see how complex a nesting of
4468 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4469 we don't care (to avoid spending too much time on complex expressions.). */
4472 count_cond (expr
, lim
)
4478 if (TREE_CODE (expr
) != COND_EXPR
)
4483 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4484 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4485 return MIN (lim
, 1 + ctrue
+ cfalse
);
4488 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4489 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4490 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4491 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4492 COND is the first argument to CODE; otherwise (as in the example
4493 given here), it is the second argument. TYPE is the type of the
4494 original expression. */
4497 fold_binary_op_with_conditional_arg (code
, type
, cond
, arg
, cond_first_p
)
4498 enum tree_code code
;
4504 tree test
, true_value
, false_value
;
4505 tree lhs
= NULL_TREE
;
4506 tree rhs
= NULL_TREE
;
4507 /* In the end, we'll produce a COND_EXPR. Both arms of the
4508 conditional expression will be binary operations. The left-hand
4509 side of the expression to be executed if the condition is true
4510 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4511 of the expression to be executed if the condition is true will be
4512 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4513 but apply to the expression to be executed if the conditional is
4519 /* These are the codes to use for the left-hand side and right-hand
4520 side of the COND_EXPR. Normally, they are the same as CODE. */
4521 enum tree_code lhs_code
= code
;
4522 enum tree_code rhs_code
= code
;
4523 /* And these are the types of the expressions. */
4524 tree lhs_type
= type
;
4525 tree rhs_type
= type
;
4530 true_rhs
= false_rhs
= &arg
;
4531 true_lhs
= &true_value
;
4532 false_lhs
= &false_value
;
4536 true_lhs
= false_lhs
= &arg
;
4537 true_rhs
= &true_value
;
4538 false_rhs
= &false_value
;
4541 if (TREE_CODE (cond
) == COND_EXPR
)
4543 test
= TREE_OPERAND (cond
, 0);
4544 true_value
= TREE_OPERAND (cond
, 1);
4545 false_value
= TREE_OPERAND (cond
, 2);
4546 /* If this operand throws an expression, then it does not make
4547 sense to try to perform a logical or arithmetic operation
4548 involving it. Instead of building `a + throw 3' for example,
4549 we simply build `a, throw 3'. */
4550 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4554 lhs_code
= COMPOUND_EXPR
;
4555 lhs_type
= void_type_node
;
4560 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4564 rhs_code
= COMPOUND_EXPR
;
4565 rhs_type
= void_type_node
;
4573 tree testtype
= TREE_TYPE (cond
);
4575 true_value
= convert (testtype
, integer_one_node
);
4576 false_value
= convert (testtype
, integer_zero_node
);
4579 /* If ARG is complex we want to make sure we only evaluate it once. Though
4580 this is only required if it is volatile, it might be more efficient even
4581 if it is not. However, if we succeed in folding one part to a constant,
4582 we do not need to make this SAVE_EXPR. Since we do this optimization
4583 primarily to see if we do end up with constant and this SAVE_EXPR
4584 interferes with later optimizations, suppressing it when we can is
4587 If we are not in a function, we can't make a SAVE_EXPR, so don't try to
4588 do so. Don't try to see if the result is a constant if an arm is a
4589 COND_EXPR since we get exponential behavior in that case. */
4591 if (saved_expr_p (arg
))
4593 else if (lhs
== 0 && rhs
== 0
4594 && !TREE_CONSTANT (arg
)
4595 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4596 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4597 || TREE_SIDE_EFFECTS (arg
)))
4599 if (TREE_CODE (true_value
) != COND_EXPR
)
4600 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4602 if (TREE_CODE (false_value
) != COND_EXPR
)
4603 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4605 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4606 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4608 arg
= save_expr (arg
);
4615 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4617 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4619 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4622 return build (COMPOUND_EXPR
, type
,
4623 convert (void_type_node
, arg
),
4624 strip_compound_expr (test
, arg
));
4626 return convert (type
, test
);
4630 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4632 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4633 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4634 ADDEND is the same as X.
4636 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4637 and finite. The problematic cases are when X is zero, and its mode
4638 has signed zeros. In the case of rounding towards -infinity,
4639 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4640 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4643 fold_real_zero_addition_p (type
, addend
, negate
)
4647 if (!real_zerop (addend
))
4650 /* Don't allow the fold with -fsignaling-nans. */
4651 if (HONOR_SNANS (TYPE_MODE (type
)))
4654 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4655 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4658 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4659 if (TREE_CODE (addend
) == REAL_CST
4660 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4663 /* The mode has signed zeros, and we have to honor their sign.
4664 In this situation, there is only one case we can return true for.
4665 X - 0 is the same as X unless rounding towards -infinity is
4667 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4670 /* Subroutine of fold() that checks comparisons of built-in math
4671 functions against real constants.
4673 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
4674 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
4675 is the type of the result and ARG0 and ARG1 are the operands of the
4676 comparison. ARG1 must be a TREE_REAL_CST.
4678 The function returns the constant folded tree if a simplification
4679 can be made, and NULL_TREE otherwise. */
4682 fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
)
4683 enum built_in_function fcode
;
4684 enum tree_code code
;
4685 tree type
, arg0
, arg1
;
4689 if (fcode
== BUILT_IN_SQRT
4690 || fcode
== BUILT_IN_SQRTF
4691 || fcode
== BUILT_IN_SQRTL
)
4693 tree arg
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
4694 enum machine_mode mode
= TYPE_MODE (TREE_TYPE (arg0
));
4696 c
= TREE_REAL_CST (arg1
);
4697 if (REAL_VALUE_NEGATIVE (c
))
4699 /* sqrt(x) < y is always false, if y is negative. */
4700 if (code
== EQ_EXPR
|| code
== LT_EXPR
|| code
== LE_EXPR
)
4701 return omit_one_operand (type
,
4702 convert (type
, integer_zero_node
),
4705 /* sqrt(x) > y is always true, if y is negative and we
4706 don't care about NaNs, i.e. negative values of x. */
4707 if (code
== NE_EXPR
|| !HONOR_NANS (mode
))
4708 return omit_one_operand (type
,
4709 convert (type
, integer_one_node
),
4712 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
4713 return fold (build (GE_EXPR
, type
, arg
,
4714 build_real (TREE_TYPE (arg
), dconst0
)));
4716 else if (code
== GT_EXPR
|| code
== GE_EXPR
)
4720 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4721 real_convert (&c2
, mode
, &c2
);
4723 if (REAL_VALUE_ISINF (c2
))
4725 /* sqrt(x) > y is x == +Inf, when y is very large. */
4726 if (HONOR_INFINITIES (mode
))
4727 return fold (build (EQ_EXPR
, type
, arg
,
4728 build_real (TREE_TYPE (arg
), c2
)));
4730 /* sqrt(x) > y is always false, when y is very large
4731 and we don't care about infinities. */
4732 return omit_one_operand (type
,
4733 convert (type
, integer_zero_node
),
4737 /* sqrt(x) > c is the same as x > c*c. */
4738 return fold (build (code
, type
, arg
,
4739 build_real (TREE_TYPE (arg
), c2
)));
4741 else if (code
== LT_EXPR
|| code
== LE_EXPR
)
4745 REAL_ARITHMETIC (c2
, MULT_EXPR
, c
, c
);
4746 real_convert (&c2
, mode
, &c2
);
4748 if (REAL_VALUE_ISINF (c2
))
4750 /* sqrt(x) < y is always true, when y is a very large
4751 value and we don't care about NaNs or Infinities. */
4752 if (! HONOR_NANS (mode
) && ! HONOR_INFINITIES (mode
))
4753 return omit_one_operand (type
,
4754 convert (type
, integer_one_node
),
4757 /* sqrt(x) < y is x != +Inf when y is very large and we
4758 don't care about NaNs. */
4759 if (! HONOR_NANS (mode
))
4760 return fold (build (NE_EXPR
, type
, arg
,
4761 build_real (TREE_TYPE (arg
), c2
)));
4763 /* sqrt(x) < y is x >= 0 when y is very large and we
4764 don't care about Infinities. */
4765 if (! HONOR_INFINITIES (mode
))
4766 return fold (build (GE_EXPR
, type
, arg
,
4767 build_real (TREE_TYPE (arg
), dconst0
)));
4769 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
4770 if ((*lang_hooks
.decls
.global_bindings_p
) () != 0
4771 || CONTAINS_PLACEHOLDER_P (arg
))
4774 arg
= save_expr (arg
);
4775 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4776 fold (build (GE_EXPR
, type
, arg
,
4777 build_real (TREE_TYPE (arg
),
4779 fold (build (NE_EXPR
, type
, arg
,
4780 build_real (TREE_TYPE (arg
),
4784 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
4785 if (! HONOR_NANS (mode
))
4786 return fold (build (code
, type
, arg
,
4787 build_real (TREE_TYPE (arg
), c2
)));
4789 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
4790 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4791 && ! CONTAINS_PLACEHOLDER_P (arg
))
4793 arg
= save_expr (arg
);
4794 return fold (build (TRUTH_ANDIF_EXPR
, type
,
4795 fold (build (GE_EXPR
, type
, arg
,
4796 build_real (TREE_TYPE (arg
),
4798 fold (build (code
, type
, arg
,
4799 build_real (TREE_TYPE (arg
),
4808 /* Subroutine of fold() that optimizes comparisons against Infinities,
4809 either +Inf or -Inf.
4811 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
4812 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
4813 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
4815 The function returns the constant folded tree if a simplification
4816 can be made, and NULL_TREE otherwise. */
4819 fold_inf_compare (code
, type
, arg0
, arg1
)
4820 enum tree_code code
;
4821 tree type
, arg0
, arg1
;
4823 enum machine_mode mode
;
4824 REAL_VALUE_TYPE max
;
4828 mode
= TYPE_MODE (TREE_TYPE (arg0
));
4830 /* For negative infinity swap the sense of the comparison. */
4831 neg
= REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1
));
4833 code
= swap_tree_comparison (code
);
4838 /* x > +Inf is always false, if with ignore sNANs. */
4839 if (HONOR_SNANS (mode
))
4841 return omit_one_operand (type
,
4842 convert (type
, integer_zero_node
),
4846 /* x <= +Inf is always true, if we don't case about NaNs. */
4847 if (! HONOR_NANS (mode
))
4848 return omit_one_operand (type
,
4849 convert (type
, integer_one_node
),
4852 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
4853 if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4854 && ! CONTAINS_PLACEHOLDER_P (arg0
))
4856 arg0
= save_expr (arg0
);
4857 return fold (build (EQ_EXPR
, type
, arg0
, arg0
));
4863 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
4864 real_maxval (&max
, neg
, mode
);
4865 return fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4866 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4869 /* x < +Inf is always equal to x <= DBL_MAX. */
4870 real_maxval (&max
, neg
, mode
);
4871 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4872 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4875 /* x != +Inf is always equal to !(x > DBL_MAX). */
4876 real_maxval (&max
, neg
, mode
);
4877 if (! HONOR_NANS (mode
))
4878 return fold (build (neg
? GE_EXPR
: LE_EXPR
, type
,
4879 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4880 temp
= fold (build (neg
? LT_EXPR
: GT_EXPR
, type
,
4881 arg0
, build_real (TREE_TYPE (arg0
), max
)));
4882 return fold (build1 (TRUTH_NOT_EXPR
, type
, temp
));
4891 /* Perform constant folding and related simplification of EXPR.
4892 The related simplifications include x*1 => x, x*0 => 0, etc.,
4893 and application of the associative law.
4894 NOP_EXPR conversions may be removed freely (as long as we
4895 are careful not to change the C type of the overall expression)
4896 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4897 but we can constant-fold them if they have constant operands. */
4904 tree t1
= NULL_TREE
;
4906 tree type
= TREE_TYPE (expr
);
4907 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4908 enum tree_code code
= TREE_CODE (t
);
4909 int kind
= TREE_CODE_CLASS (code
);
4911 /* WINS will be nonzero when the switch is done
4912 if all operands are constant. */
4915 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4916 Likewise for a SAVE_EXPR that's already been evaluated. */
4917 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4920 /* Return right away if a constant. */
4924 #ifdef MAX_INTEGER_COMPUTATION_MODE
4925 check_max_integer_computation_mode (expr
);
4928 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4932 /* Special case for conversion ops that can have fixed point args. */
4933 arg0
= TREE_OPERAND (t
, 0);
4935 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4937 STRIP_SIGN_NOPS (arg0
);
4939 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4940 subop
= TREE_REALPART (arg0
);
4944 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4945 && TREE_CODE (subop
) != REAL_CST
4947 /* Note that TREE_CONSTANT isn't enough:
4948 static var addresses are constant but we can't
4949 do arithmetic on them. */
4952 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
4954 int len
= first_rtl_op (code
);
4956 for (i
= 0; i
< len
; i
++)
4958 tree op
= TREE_OPERAND (t
, i
);
4962 continue; /* Valid for CALL_EXPR, at least. */
4964 if (kind
== '<' || code
== RSHIFT_EXPR
)
4966 /* Signedness matters here. Perhaps we can refine this
4968 STRIP_SIGN_NOPS (op
);
4971 /* Strip any conversions that don't change the mode. */
4974 if (TREE_CODE (op
) == COMPLEX_CST
)
4975 subop
= TREE_REALPART (op
);
4979 if (TREE_CODE (subop
) != INTEGER_CST
4980 && TREE_CODE (subop
) != REAL_CST
)
4981 /* Note that TREE_CONSTANT isn't enough:
4982 static var addresses are constant but we can't
4983 do arithmetic on them. */
4993 /* If this is a commutative operation, and ARG0 is a constant, move it
4994 to ARG1 to reduce the number of tests below. */
4995 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
4996 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
4997 || code
== BIT_AND_EXPR
)
4998 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
5000 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
5002 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
5003 TREE_OPERAND (t
, 1) = tem
;
5006 /* Now WINS is set as described above,
5007 ARG0 is the first operand of EXPR,
5008 and ARG1 is the second operand (if it has more than one operand).
5010 First check for cases where an arithmetic operation is applied to a
5011 compound, conditional, or comparison operation. Push the arithmetic
5012 operation inside the compound or conditional to see if any folding
5013 can then be done. Convert comparison to conditional for this purpose.
5014 The also optimizes non-constant cases that used to be done in
5017 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
5018 one of the operands is a comparison and the other is a comparison, a
5019 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
5020 code below would make the expression more complex. Change it to a
5021 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
5022 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
5024 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
5025 || code
== EQ_EXPR
|| code
== NE_EXPR
)
5026 && ((truth_value_p (TREE_CODE (arg0
))
5027 && (truth_value_p (TREE_CODE (arg1
))
5028 || (TREE_CODE (arg1
) == BIT_AND_EXPR
5029 && integer_onep (TREE_OPERAND (arg1
, 1)))))
5030 || (truth_value_p (TREE_CODE (arg1
))
5031 && (truth_value_p (TREE_CODE (arg0
))
5032 || (TREE_CODE (arg0
) == BIT_AND_EXPR
5033 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
5035 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
5036 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
5040 if (code
== EQ_EXPR
)
5041 t
= invert_truthvalue (t
);
5046 if (TREE_CODE_CLASS (code
) == '1')
5048 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5049 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5050 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
5051 else if (TREE_CODE (arg0
) == COND_EXPR
)
5053 tree arg01
= TREE_OPERAND (arg0
, 1);
5054 tree arg02
= TREE_OPERAND (arg0
, 2);
5055 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
5056 arg01
= fold (build1 (code
, type
, arg01
));
5057 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
5058 arg02
= fold (build1 (code
, type
, arg02
));
5059 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5062 /* If this was a conversion, and all we did was to move into
5063 inside the COND_EXPR, bring it back out. But leave it if
5064 it is a conversion from integer to integer and the
5065 result precision is no wider than a word since such a
5066 conversion is cheap and may be optimized away by combine,
5067 while it couldn't if it were outside the COND_EXPR. Then return
5068 so we don't get into an infinite recursion loop taking the
5069 conversion out and then back in. */
5071 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
5072 || code
== NON_LVALUE_EXPR
)
5073 && TREE_CODE (t
) == COND_EXPR
5074 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
5075 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
5076 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
5077 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
5078 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
5079 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
5080 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5082 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
5083 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
5084 t
= build1 (code
, type
,
5086 TREE_TYPE (TREE_OPERAND
5087 (TREE_OPERAND (t
, 1), 0)),
5088 TREE_OPERAND (t
, 0),
5089 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
5090 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
5093 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
5094 return fold (build (COND_EXPR
, type
, arg0
,
5095 fold (build1 (code
, type
, integer_one_node
)),
5096 fold (build1 (code
, type
, integer_zero_node
))));
5098 else if (TREE_CODE_CLASS (code
) == '<'
5099 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
5100 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5101 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5102 else if (TREE_CODE_CLASS (code
) == '<'
5103 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
5104 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5105 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
5106 else if (TREE_CODE_CLASS (code
) == '2'
5107 || TREE_CODE_CLASS (code
) == '<')
5109 if (TREE_CODE (arg1
) == COMPOUND_EXPR
5110 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
5111 && ! TREE_SIDE_EFFECTS (arg0
))
5112 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
5113 fold (build (code
, type
,
5114 arg0
, TREE_OPERAND (arg1
, 1))));
5115 else if ((TREE_CODE (arg1
) == COND_EXPR
5116 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
5117 && TREE_CODE_CLASS (code
) != '<'))
5118 && (TREE_CODE (arg0
) != COND_EXPR
5119 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5120 && (! TREE_SIDE_EFFECTS (arg0
)
5121 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5122 && ! CONTAINS_PLACEHOLDER_P (arg0
))))
5124 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
5125 /*cond_first_p=*/0);
5126 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
5127 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5128 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
5129 else if ((TREE_CODE (arg0
) == COND_EXPR
5130 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
5131 && TREE_CODE_CLASS (code
) != '<'))
5132 && (TREE_CODE (arg1
) != COND_EXPR
5133 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
5134 && (! TREE_SIDE_EFFECTS (arg1
)
5135 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
5136 && ! CONTAINS_PLACEHOLDER_P (arg1
))))
5138 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
5139 /*cond_first_p=*/1);
5153 return fold (DECL_INITIAL (t
));
5158 case FIX_TRUNC_EXPR
:
5159 /* Other kinds of FIX are not handled properly by fold_convert. */
5161 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
5162 return TREE_OPERAND (t
, 0);
5164 /* Handle cases of two conversions in a row. */
5165 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
5166 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
5168 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5169 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
5170 tree final_type
= TREE_TYPE (t
);
5171 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
5172 int inside_ptr
= POINTER_TYPE_P (inside_type
);
5173 int inside_float
= FLOAT_TYPE_P (inside_type
);
5174 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
5175 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
5176 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
5177 int inter_ptr
= POINTER_TYPE_P (inter_type
);
5178 int inter_float
= FLOAT_TYPE_P (inter_type
);
5179 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
5180 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
5181 int final_int
= INTEGRAL_TYPE_P (final_type
);
5182 int final_ptr
= POINTER_TYPE_P (final_type
);
5183 int final_float
= FLOAT_TYPE_P (final_type
);
5184 unsigned int final_prec
= TYPE_PRECISION (final_type
);
5185 int final_unsignedp
= TREE_UNSIGNED (final_type
);
5187 /* In addition to the cases of two conversions in a row
5188 handled below, if we are converting something to its own
5189 type via an object of identical or wider precision, neither
5190 conversion is needed. */
5191 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
5192 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
5193 && inter_prec
>= final_prec
)
5194 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5196 /* Likewise, if the intermediate and final types are either both
5197 float or both integer, we don't need the middle conversion if
5198 it is wider than the final type and doesn't change the signedness
5199 (for integers). Avoid this if the final type is a pointer
5200 since then we sometimes need the inner conversion. Likewise if
5201 the outer has a precision not equal to the size of its mode. */
5202 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
5203 || (inter_float
&& inside_float
))
5204 && inter_prec
>= inside_prec
5205 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
5206 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5207 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5209 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5211 /* If we have a sign-extension of a zero-extended value, we can
5212 replace that by a single zero-extension. */
5213 if (inside_int
&& inter_int
&& final_int
5214 && inside_prec
< inter_prec
&& inter_prec
< final_prec
5215 && inside_unsignedp
&& !inter_unsignedp
)
5216 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5218 /* Two conversions in a row are not needed unless:
5219 - some conversion is floating-point (overstrict for now), or
5220 - the intermediate type is narrower than both initial and
5222 - the intermediate type and innermost type differ in signedness,
5223 and the outermost type is wider than the intermediate, or
5224 - the initial type is a pointer type and the precisions of the
5225 intermediate and final types differ, or
5226 - the final type is a pointer type and the precisions of the
5227 initial and intermediate types differ. */
5228 if (! inside_float
&& ! inter_float
&& ! final_float
5229 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5230 && ! (inside_int
&& inter_int
5231 && inter_unsignedp
!= inside_unsignedp
5232 && inter_prec
< final_prec
)
5233 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5234 == (final_unsignedp
&& final_prec
> inter_prec
))
5235 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5236 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5237 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5238 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5240 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5243 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5244 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5245 /* Detect assigning a bitfield. */
5246 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5247 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5249 /* Don't leave an assignment inside a conversion
5250 unless assigning a bitfield. */
5251 tree prev
= TREE_OPERAND (t
, 0);
5252 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5253 /* First do the assignment, then return converted constant. */
5254 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5259 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5260 constants (if x has signed type, the sign bit cannot be set
5261 in c). This folds extension into the BIT_AND_EXPR. */
5262 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5263 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5264 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5265 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5267 tree
and = TREE_OPERAND (t
, 0);
5268 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5271 if (TREE_UNSIGNED (TREE_TYPE (and))
5272 || (TYPE_PRECISION (TREE_TYPE (t
))
5273 <= TYPE_PRECISION (TREE_TYPE (and))))
5275 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5276 <= HOST_BITS_PER_WIDE_INT
5277 && host_integerp (and1
, 1))
5279 unsigned HOST_WIDE_INT cst
;
5281 cst
= tree_low_cst (and1
, 1);
5282 cst
&= (HOST_WIDE_INT
) -1
5283 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5284 change
= (cst
== 0);
5285 #ifdef LOAD_EXTEND_OP
5287 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5290 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5291 and0
= convert (uns
, and0
);
5292 and1
= convert (uns
, and1
);
5297 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5298 convert (TREE_TYPE (t
), and0
),
5299 convert (TREE_TYPE (t
), and1
)));
5304 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5307 return fold_convert (t
, arg0
);
5309 case VIEW_CONVERT_EXPR
:
5310 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5311 return build1 (VIEW_CONVERT_EXPR
, type
,
5312 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5316 if (TREE_CODE (arg0
) == CONSTRUCTOR
5317 && ! type_contains_placeholder_p (TREE_TYPE (arg0
)))
5319 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5326 TREE_CONSTANT (t
) = wins
;
5332 if (TREE_CODE (arg0
) == INTEGER_CST
)
5334 unsigned HOST_WIDE_INT low
;
5336 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5337 TREE_INT_CST_HIGH (arg0
),
5339 t
= build_int_2 (low
, high
);
5340 TREE_TYPE (t
) = type
;
5342 = (TREE_OVERFLOW (arg0
)
5343 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5344 TREE_CONSTANT_OVERFLOW (t
)
5345 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5347 else if (TREE_CODE (arg0
) == REAL_CST
)
5348 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5350 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5351 return TREE_OPERAND (arg0
, 0);
5352 /* Convert -((double)float) into (double)(-float). */
5353 else if (TREE_CODE (arg0
) == NOP_EXPR
5354 && TREE_CODE (type
) == REAL_TYPE
)
5356 tree targ0
= strip_float_extensions (arg0
);
5358 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (targ0
), targ0
));
5362 /* Convert - (a - b) to (b - a) for non-floating-point. */
5363 else if (TREE_CODE (arg0
) == MINUS_EXPR
5364 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5365 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5366 TREE_OPERAND (arg0
, 0));
5373 if (TREE_CODE (arg0
) == INTEGER_CST
)
5375 /* If the value is unsigned, then the absolute value is
5376 the same as the ordinary value. */
5377 if (TREE_UNSIGNED (type
))
5379 /* Similarly, if the value is non-negative. */
5380 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5382 /* If the value is negative, then the absolute value is
5386 unsigned HOST_WIDE_INT low
;
5388 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5389 TREE_INT_CST_HIGH (arg0
),
5391 t
= build_int_2 (low
, high
);
5392 TREE_TYPE (t
) = type
;
5394 = (TREE_OVERFLOW (arg0
)
5395 | force_fit_type (t
, overflow
));
5396 TREE_CONSTANT_OVERFLOW (t
)
5397 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5400 else if (TREE_CODE (arg0
) == REAL_CST
)
5402 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5403 t
= build_real (type
,
5404 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5407 else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
5408 return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5409 /* Convert fabs((double)float) into (double)fabsf(float). */
5410 else if (TREE_CODE (arg0
) == NOP_EXPR
5411 && TREE_CODE (type
) == REAL_TYPE
)
5413 tree targ0
= strip_float_extensions (arg0
);
5415 return convert (type
, build1 (ABS_EXPR
, TREE_TYPE (targ0
), targ0
));
5420 /* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */
5421 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
5422 if (fcode
== BUILT_IN_SQRT
5423 || fcode
== BUILT_IN_SQRTF
5424 || fcode
== BUILT_IN_SQRTL
5425 || fcode
== BUILT_IN_EXP
5426 || fcode
== BUILT_IN_EXPF
5427 || fcode
== BUILT_IN_EXPL
)
5433 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5434 return convert (type
, arg0
);
5435 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5436 return build (COMPLEX_EXPR
, type
,
5437 TREE_OPERAND (arg0
, 0),
5438 negate_expr (TREE_OPERAND (arg0
, 1)));
5439 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5440 return build_complex (type
, TREE_REALPART (arg0
),
5441 negate_expr (TREE_IMAGPART (arg0
)));
5442 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5443 return fold (build (TREE_CODE (arg0
), type
,
5444 fold (build1 (CONJ_EXPR
, type
,
5445 TREE_OPERAND (arg0
, 0))),
5446 fold (build1 (CONJ_EXPR
,
5447 type
, TREE_OPERAND (arg0
, 1)))));
5448 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5449 return TREE_OPERAND (arg0
, 0);
5455 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5456 ~ TREE_INT_CST_HIGH (arg0
));
5457 TREE_TYPE (t
) = type
;
5458 force_fit_type (t
, 0);
5459 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5460 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5462 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5463 return TREE_OPERAND (arg0
, 0);
5467 /* A + (-B) -> A - B */
5468 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5469 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5470 /* (-A) + B -> B - A */
5471 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5472 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5473 else if (! FLOAT_TYPE_P (type
))
5475 if (integer_zerop (arg1
))
5476 return non_lvalue (convert (type
, arg0
));
5478 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5479 with a constant, and the two constants have no bits in common,
5480 we should treat this as a BIT_IOR_EXPR since this may produce more
5482 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5483 && TREE_CODE (arg1
) == BIT_AND_EXPR
5484 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5485 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5486 && integer_zerop (const_binop (BIT_AND_EXPR
,
5487 TREE_OPERAND (arg0
, 1),
5488 TREE_OPERAND (arg1
, 1), 0)))
5490 code
= BIT_IOR_EXPR
;
5494 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5495 (plus (plus (mult) (mult)) (foo)) so that we can
5496 take advantage of the factoring cases below. */
5497 if ((TREE_CODE (arg0
) == PLUS_EXPR
5498 && TREE_CODE (arg1
) == MULT_EXPR
)
5499 || (TREE_CODE (arg1
) == PLUS_EXPR
5500 && TREE_CODE (arg0
) == MULT_EXPR
))
5502 tree parg0
, parg1
, parg
, marg
;
5504 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5505 parg
= arg0
, marg
= arg1
;
5507 parg
= arg1
, marg
= arg0
;
5508 parg0
= TREE_OPERAND (parg
, 0);
5509 parg1
= TREE_OPERAND (parg
, 1);
5513 if (TREE_CODE (parg0
) == MULT_EXPR
5514 && TREE_CODE (parg1
) != MULT_EXPR
)
5515 return fold (build (PLUS_EXPR
, type
,
5516 fold (build (PLUS_EXPR
, type
,
5517 convert (type
, parg0
),
5518 convert (type
, marg
))),
5519 convert (type
, parg1
)));
5520 if (TREE_CODE (parg0
) != MULT_EXPR
5521 && TREE_CODE (parg1
) == MULT_EXPR
)
5522 return fold (build (PLUS_EXPR
, type
,
5523 fold (build (PLUS_EXPR
, type
,
5524 convert (type
, parg1
),
5525 convert (type
, marg
))),
5526 convert (type
, parg0
)));
5529 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5531 tree arg00
, arg01
, arg10
, arg11
;
5532 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5534 /* (A * C) + (B * C) -> (A+B) * C.
5535 We are most concerned about the case where C is a constant,
5536 but other combinations show up during loop reduction. Since
5537 it is not difficult, try all four possibilities. */
5539 arg00
= TREE_OPERAND (arg0
, 0);
5540 arg01
= TREE_OPERAND (arg0
, 1);
5541 arg10
= TREE_OPERAND (arg1
, 0);
5542 arg11
= TREE_OPERAND (arg1
, 1);
5545 if (operand_equal_p (arg01
, arg11
, 0))
5546 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5547 else if (operand_equal_p (arg00
, arg10
, 0))
5548 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5549 else if (operand_equal_p (arg00
, arg11
, 0))
5550 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5551 else if (operand_equal_p (arg01
, arg10
, 0))
5552 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5554 /* No identical multiplicands; see if we can find a common
5555 power-of-two factor in non-power-of-two multiplies. This
5556 can help in multi-dimensional array access. */
5557 else if (TREE_CODE (arg01
) == INTEGER_CST
5558 && TREE_CODE (arg11
) == INTEGER_CST
5559 && TREE_INT_CST_HIGH (arg01
) == 0
5560 && TREE_INT_CST_HIGH (arg11
) == 0)
5562 HOST_WIDE_INT int01
, int11
, tmp
;
5563 int01
= TREE_INT_CST_LOW (arg01
);
5564 int11
= TREE_INT_CST_LOW (arg11
);
5566 /* Move min of absolute values to int11. */
5567 if ((int01
>= 0 ? int01
: -int01
)
5568 < (int11
>= 0 ? int11
: -int11
))
5570 tmp
= int01
, int01
= int11
, int11
= tmp
;
5571 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5572 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5575 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5577 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5578 build_int_2 (int01
/ int11
, 0)));
5585 return fold (build (MULT_EXPR
, type
,
5586 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5591 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5592 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
5593 return non_lvalue (convert (type
, arg0
));
5595 /* Likewise if the operands are reversed. */
5596 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5597 return non_lvalue (convert (type
, arg1
));
5600 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5601 is a rotate of A by C1 bits. */
5602 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5603 is a rotate of A by B bits. */
5605 enum tree_code code0
, code1
;
5606 code0
= TREE_CODE (arg0
);
5607 code1
= TREE_CODE (arg1
);
5608 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5609 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5610 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5611 TREE_OPERAND (arg1
, 0), 0)
5612 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5614 tree tree01
, tree11
;
5615 enum tree_code code01
, code11
;
5617 tree01
= TREE_OPERAND (arg0
, 1);
5618 tree11
= TREE_OPERAND (arg1
, 1);
5619 STRIP_NOPS (tree01
);
5620 STRIP_NOPS (tree11
);
5621 code01
= TREE_CODE (tree01
);
5622 code11
= TREE_CODE (tree11
);
5623 if (code01
== INTEGER_CST
5624 && code11
== INTEGER_CST
5625 && TREE_INT_CST_HIGH (tree01
) == 0
5626 && TREE_INT_CST_HIGH (tree11
) == 0
5627 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5628 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5629 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5630 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5631 else if (code11
== MINUS_EXPR
)
5633 tree tree110
, tree111
;
5634 tree110
= TREE_OPERAND (tree11
, 0);
5635 tree111
= TREE_OPERAND (tree11
, 1);
5636 STRIP_NOPS (tree110
);
5637 STRIP_NOPS (tree111
);
5638 if (TREE_CODE (tree110
) == INTEGER_CST
5639 && 0 == compare_tree_int (tree110
,
5641 (TREE_TYPE (TREE_OPERAND
5643 && operand_equal_p (tree01
, tree111
, 0))
5644 return build ((code0
== LSHIFT_EXPR
5647 type
, TREE_OPERAND (arg0
, 0), tree01
);
5649 else if (code01
== MINUS_EXPR
)
5651 tree tree010
, tree011
;
5652 tree010
= TREE_OPERAND (tree01
, 0);
5653 tree011
= TREE_OPERAND (tree01
, 1);
5654 STRIP_NOPS (tree010
);
5655 STRIP_NOPS (tree011
);
5656 if (TREE_CODE (tree010
) == INTEGER_CST
5657 && 0 == compare_tree_int (tree010
,
5659 (TREE_TYPE (TREE_OPERAND
5661 && operand_equal_p (tree11
, tree011
, 0))
5662 return build ((code0
!= LSHIFT_EXPR
5665 type
, TREE_OPERAND (arg0
, 0), tree11
);
5671 /* In most languages, can't associate operations on floats through
5672 parentheses. Rather than remember where the parentheses were, we
5673 don't associate floats at all. It shouldn't matter much. However,
5674 associating multiplications is only very slightly inaccurate, so do
5675 that if -funsafe-math-optimizations is specified. */
5678 && (! FLOAT_TYPE_P (type
)
5679 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5681 tree var0
, con0
, lit0
, minus_lit0
;
5682 tree var1
, con1
, lit1
, minus_lit1
;
5684 /* Split both trees into variables, constants, and literals. Then
5685 associate each group together, the constants with literals,
5686 then the result with variables. This increases the chances of
5687 literals being recombined later and of generating relocatable
5688 expressions for the sum of a constant and literal. */
5689 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
5690 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
5691 code
== MINUS_EXPR
);
5693 /* Only do something if we found more than two objects. Otherwise,
5694 nothing has changed and we risk infinite recursion. */
5695 if (2 < ((var0
!= 0) + (var1
!= 0)
5696 + (con0
!= 0) + (con1
!= 0)
5697 + (lit0
!= 0) + (lit1
!= 0)
5698 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
5700 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5701 if (code
== MINUS_EXPR
)
5704 var0
= associate_trees (var0
, var1
, code
, type
);
5705 con0
= associate_trees (con0
, con1
, code
, type
);
5706 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5707 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
5709 /* Preserve the MINUS_EXPR if the negative part of the literal is
5710 greater than the positive part. Otherwise, the multiplicative
5711 folding code (i.e extract_muldiv) may be fooled in case
5712 unsigned constants are substracted, like in the following
5713 example: ((X*2 + 4) - 8U)/2. */
5714 if (minus_lit0
&& lit0
)
5716 if (tree_int_cst_lt (lit0
, minus_lit0
))
5718 minus_lit0
= associate_trees (minus_lit0
, lit0
,
5724 lit0
= associate_trees (lit0
, minus_lit0
,
5732 return convert (type
, associate_trees (var0
, minus_lit0
,
5736 con0
= associate_trees (con0
, minus_lit0
,
5738 return convert (type
, associate_trees (var0
, con0
,
5743 con0
= associate_trees (con0
, lit0
, code
, type
);
5744 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5750 t1
= const_binop (code
, arg0
, arg1
, 0);
5751 if (t1
!= NULL_TREE
)
5753 /* The return value should always have
5754 the same type as the original expression. */
5755 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5756 t1
= convert (TREE_TYPE (t
), t1
);
5763 /* A - (-B) -> A + B */
5764 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5765 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5766 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5767 if (TREE_CODE (arg0
) == NEGATE_EXPR
5768 && FLOAT_TYPE_P (type
)
5769 && negate_expr_p (arg1
)
5770 && (! TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
5771 && (! TREE_SIDE_EFFECTS (arg1
) || TREE_CONSTANT (arg0
)))
5772 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
5773 TREE_OPERAND (arg0
, 0)));
5775 if (! FLOAT_TYPE_P (type
))
5777 if (! wins
&& integer_zerop (arg0
))
5778 return negate_expr (convert (type
, arg1
));
5779 if (integer_zerop (arg1
))
5780 return non_lvalue (convert (type
, arg0
));
5782 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5783 about the case where C is a constant, just try one of the
5784 four possibilities. */
5786 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5787 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5788 TREE_OPERAND (arg1
, 1), 0))
5789 return fold (build (MULT_EXPR
, type
,
5790 fold (build (MINUS_EXPR
, type
,
5791 TREE_OPERAND (arg0
, 0),
5792 TREE_OPERAND (arg1
, 0))),
5793 TREE_OPERAND (arg0
, 1)));
5795 /* Fold A - (A & B) into ~B & A. */
5796 if (!TREE_SIDE_EFFECTS (arg0
)
5797 && TREE_CODE (arg1
) == BIT_AND_EXPR
)
5799 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 1), 0))
5800 return fold (build (BIT_AND_EXPR
, type
,
5801 fold (build1 (BIT_NOT_EXPR
, type
,
5802 TREE_OPERAND (arg1
, 0))),
5804 if (operand_equal_p (arg0
, TREE_OPERAND (arg1
, 0), 0))
5805 return fold (build (BIT_AND_EXPR
, type
,
5806 fold (build1 (BIT_NOT_EXPR
, type
,
5807 TREE_OPERAND (arg1
, 1))),
5812 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5813 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
5814 return non_lvalue (convert (type
, arg0
));
5816 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5817 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5818 (-ARG1 + ARG0) reduces to -ARG1. */
5819 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5820 return negate_expr (convert (type
, arg1
));
5822 /* Fold &x - &x. This can happen from &x.foo - &x.
5823 This is unsafe for certain floats even in non-IEEE formats.
5824 In IEEE, it is unsafe because it does wrong for NaNs.
5825 Also note that operand_equal_p is always false if an operand
5828 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5829 && operand_equal_p (arg0
, arg1
, 0))
5830 return convert (type
, integer_zero_node
);
5835 /* (-A) * (-B) -> A * B */
5836 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5837 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5838 TREE_OPERAND (arg1
, 0)));
5840 if (! FLOAT_TYPE_P (type
))
5842 if (integer_zerop (arg1
))
5843 return omit_one_operand (type
, arg1
, arg0
);
5844 if (integer_onep (arg1
))
5845 return non_lvalue (convert (type
, arg0
));
5847 /* (a * (1 << b)) is (a << b) */
5848 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5849 && integer_onep (TREE_OPERAND (arg1
, 0)))
5850 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5851 TREE_OPERAND (arg1
, 1)));
5852 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5853 && integer_onep (TREE_OPERAND (arg0
, 0)))
5854 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5855 TREE_OPERAND (arg0
, 1)));
5857 if (TREE_CODE (arg1
) == INTEGER_CST
5858 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0),
5859 convert (type
, arg1
),
5861 return convert (type
, tem
);
5866 /* Maybe fold x * 0 to 0. The expressions aren't the same
5867 when x is NaN, since x * 0 is also NaN. Nor are they the
5868 same in modes with signed zeros, since multiplying a
5869 negative value by 0 gives -0, not +0. */
5870 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
5871 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
5872 && real_zerop (arg1
))
5873 return omit_one_operand (type
, arg1
, arg0
);
5874 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5875 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5876 && real_onep (arg1
))
5877 return non_lvalue (convert (type
, arg0
));
5879 /* Transform x * -1.0 into -x. */
5880 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5881 && real_minus_onep (arg1
))
5882 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
5885 if (! wins
&& real_twop (arg1
)
5886 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
5887 && ! CONTAINS_PLACEHOLDER_P (arg0
))
5889 tree arg
= save_expr (arg0
);
5890 return fold (build (PLUS_EXPR
, type
, arg
, arg
));
5893 if (flag_unsafe_math_optimizations
)
5895 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
5896 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
5898 /* Optimizations of sqrt(...)*sqrt(...). */
5899 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
5900 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
5901 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
5903 tree sqrtfn
, arg
, arglist
;
5904 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5905 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5907 /* Optimize sqrt(x)*sqrt(x) as x. */
5908 if (operand_equal_p (arg00
, arg10
, 0)
5909 && ! HONOR_SNANS (TYPE_MODE (type
)))
5912 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5913 sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5914 arg
= fold (build (MULT_EXPR
, type
, arg00
, arg10
));
5915 arglist
= build_tree_list (NULL_TREE
, arg
);
5916 return build_function_call_expr (sqrtfn
, arglist
);
5919 /* Optimize exp(x)*exp(y) as exp(x+y). */
5920 if ((fcode0
== BUILT_IN_EXP
&& fcode1
== BUILT_IN_EXP
)
5921 || (fcode0
== BUILT_IN_EXPF
&& fcode1
== BUILT_IN_EXPF
)
5922 || (fcode0
== BUILT_IN_EXPL
&& fcode1
== BUILT_IN_EXPL
))
5924 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5925 tree arg
= build (PLUS_EXPR
, type
,
5926 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5927 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5928 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
5929 return build_function_call_expr (expfn
, arglist
);
5932 /* Optimizations of pow(...)*pow(...). */
5933 if ((fcode0
== BUILT_IN_POW
&& fcode1
== BUILT_IN_POW
)
5934 || (fcode0
== BUILT_IN_POWF
&& fcode1
== BUILT_IN_POWF
)
5935 || (fcode0
== BUILT_IN_POWL
&& fcode1
== BUILT_IN_POWL
))
5937 tree arg00
= TREE_VALUE (TREE_OPERAND (arg0
, 1));
5938 tree arg01
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg0
,
5940 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
5941 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
,
5944 /* Optimize pow(x,y)*pow(z,y) as pow(x*z,y). */
5945 if (operand_equal_p (arg01
, arg11
, 0))
5947 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5948 tree arg
= build (MULT_EXPR
, type
, arg00
, arg10
);
5949 tree arglist
= tree_cons (NULL_TREE
, fold (arg
),
5950 build_tree_list (NULL_TREE
,
5952 return build_function_call_expr (powfn
, arglist
);
5955 /* Optimize pow(x,y)*pow(x,z) as pow(x,y+z). */
5956 if (operand_equal_p (arg00
, arg10
, 0))
5958 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5959 tree arg
= fold (build (PLUS_EXPR
, type
, arg01
, arg11
));
5960 tree arglist
= tree_cons (NULL_TREE
, arg00
,
5961 build_tree_list (NULL_TREE
,
5963 return build_function_call_expr (powfn
, arglist
);
5972 if (integer_all_onesp (arg1
))
5973 return omit_one_operand (type
, arg1
, arg0
);
5974 if (integer_zerop (arg1
))
5975 return non_lvalue (convert (type
, arg0
));
5976 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5977 if (t1
!= NULL_TREE
)
5980 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5982 This results in more efficient code for machines without a NAND
5983 instruction. Combine will canonicalize to the first form
5984 which will allow use of NAND instructions provided by the
5985 backend if they exist. */
5986 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5987 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5989 return fold (build1 (BIT_NOT_EXPR
, type
,
5990 build (BIT_AND_EXPR
, type
,
5991 TREE_OPERAND (arg0
, 0),
5992 TREE_OPERAND (arg1
, 0))));
5995 /* See if this can be simplified into a rotate first. If that
5996 is unsuccessful continue in the association code. */
6000 if (integer_zerop (arg1
))
6001 return non_lvalue (convert (type
, arg0
));
6002 if (integer_all_onesp (arg1
))
6003 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
6005 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
6006 with a constant, and the two constants have no bits in common,
6007 we should treat this as a BIT_IOR_EXPR since this may produce more
6009 if (TREE_CODE (arg0
) == BIT_AND_EXPR
6010 && TREE_CODE (arg1
) == BIT_AND_EXPR
6011 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6012 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
6013 && integer_zerop (const_binop (BIT_AND_EXPR
,
6014 TREE_OPERAND (arg0
, 1),
6015 TREE_OPERAND (arg1
, 1), 0)))
6017 code
= BIT_IOR_EXPR
;
6021 /* See if this can be simplified into a rotate first. If that
6022 is unsuccessful continue in the association code. */
6027 if (integer_all_onesp (arg1
))
6028 return non_lvalue (convert (type
, arg0
));
6029 if (integer_zerop (arg1
))
6030 return omit_one_operand (type
, arg1
, arg0
);
6031 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
6032 if (t1
!= NULL_TREE
)
6034 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
6035 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
6036 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
6039 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
6041 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
6042 && (~TREE_INT_CST_LOW (arg1
)
6043 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
6044 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
6047 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
6049 This results in more efficient code for machines without a NOR
6050 instruction. Combine will canonicalize to the first form
6051 which will allow use of NOR instructions provided by the
6052 backend if they exist. */
6053 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
6054 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
6056 return fold (build1 (BIT_NOT_EXPR
, type
,
6057 build (BIT_IOR_EXPR
, type
,
6058 TREE_OPERAND (arg0
, 0),
6059 TREE_OPERAND (arg1
, 0))));
6064 case BIT_ANDTC_EXPR
:
6065 if (integer_all_onesp (arg0
))
6066 return non_lvalue (convert (type
, arg1
));
6067 if (integer_zerop (arg0
))
6068 return omit_one_operand (type
, arg0
, arg1
);
6069 if (TREE_CODE (arg1
) == INTEGER_CST
)
6071 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
6072 code
= BIT_AND_EXPR
;
6078 /* Don't touch a floating-point divide by zero unless the mode
6079 of the constant can represent infinity. */
6080 if (TREE_CODE (arg1
) == REAL_CST
6081 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
6082 && real_zerop (arg1
))
6085 /* (-A) / (-B) -> A / B */
6086 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
6087 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6088 TREE_OPERAND (arg1
, 0)));
6090 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
6091 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
6092 && real_onep (arg1
))
6093 return non_lvalue (convert (type
, arg0
));
6095 /* If ARG1 is a constant, we can convert this to a multiply by the
6096 reciprocal. This does not have the same rounding properties,
6097 so only do this if -funsafe-math-optimizations. We can actually
6098 always safely do it if ARG1 is a power of two, but it's hard to
6099 tell if it is or not in a portable manner. */
6100 if (TREE_CODE (arg1
) == REAL_CST
)
6102 if (flag_unsafe_math_optimizations
6103 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
6105 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6106 /* Find the reciprocal if optimizing and the result is exact. */
6110 r
= TREE_REAL_CST (arg1
);
6111 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
6113 tem
= build_real (type
, r
);
6114 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
6118 /* Convert A/B/C to A/(B*C). */
6119 if (flag_unsafe_math_optimizations
6120 && TREE_CODE (arg0
) == RDIV_EXPR
)
6122 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
6123 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
6126 /* Convert A/(B/C) to (A/B)*C. */
6127 if (flag_unsafe_math_optimizations
6128 && TREE_CODE (arg1
) == RDIV_EXPR
)
6130 return fold (build (MULT_EXPR
, type
,
6131 build (RDIV_EXPR
, type
, arg0
,
6132 TREE_OPERAND (arg1
, 0)),
6133 TREE_OPERAND (arg1
, 1)));
6136 if (flag_unsafe_math_optimizations
)
6138 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
6139 /* Optimize x/exp(y) into x*exp(-y). */
6140 if (fcode
== BUILT_IN_EXP
6141 || fcode
== BUILT_IN_EXPF
6142 || fcode
== BUILT_IN_EXPL
)
6144 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6145 tree arg
= build1 (NEGATE_EXPR
, type
,
6146 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
6147 tree arglist
= build_tree_list (NULL_TREE
, fold (arg
));
6148 arg1
= build_function_call_expr (expfn
, arglist
);
6149 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6152 /* Optimize x/pow(y,z) into x*pow(y,-z). */
6153 if (fcode
== BUILT_IN_POW
6154 || fcode
== BUILT_IN_POWF
6155 || fcode
== BUILT_IN_POWL
)
6157 tree powfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
6158 tree arg10
= TREE_VALUE (TREE_OPERAND (arg1
, 1));
6159 tree arg11
= TREE_VALUE (TREE_CHAIN (TREE_OPERAND (arg1
, 1)));
6160 tree neg11
= fold (build1 (NEGATE_EXPR
, type
, arg11
));
6161 tree arglist
= tree_cons(NULL_TREE
, arg10
,
6162 build_tree_list (NULL_TREE
, neg11
));
6163 arg1
= build_function_call_expr (powfn
, arglist
);
6164 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
6169 case TRUNC_DIV_EXPR
:
6170 case ROUND_DIV_EXPR
:
6171 case FLOOR_DIV_EXPR
:
6173 case EXACT_DIV_EXPR
:
6174 if (integer_onep (arg1
))
6175 return non_lvalue (convert (type
, arg0
));
6176 if (integer_zerop (arg1
))
6179 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
6180 operation, EXACT_DIV_EXPR.
6182 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
6183 At one time others generated faster code, it's not clear if they do
6184 after the last round to changes to the DIV code in expmed.c. */
6185 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
6186 && multiple_of_p (type
, arg0
, arg1
))
6187 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
6189 if (TREE_CODE (arg1
) == INTEGER_CST
6190 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6192 return convert (type
, tem
);
6197 case FLOOR_MOD_EXPR
:
6198 case ROUND_MOD_EXPR
:
6199 case TRUNC_MOD_EXPR
:
6200 if (integer_onep (arg1
))
6201 return omit_one_operand (type
, integer_zero_node
, arg0
);
6202 if (integer_zerop (arg1
))
6205 if (TREE_CODE (arg1
) == INTEGER_CST
6206 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
6208 return convert (type
, tem
);
6214 if (integer_all_onesp (arg0
))
6215 return omit_one_operand (type
, arg0
, arg1
);
6219 /* Optimize -1 >> x for arithmetic right shifts. */
6220 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
6221 return omit_one_operand (type
, arg0
, arg1
);
6222 /* ... fall through ... */
6226 if (integer_zerop (arg1
))
6227 return non_lvalue (convert (type
, arg0
));
6228 if (integer_zerop (arg0
))
6229 return omit_one_operand (type
, arg0
, arg1
);
6231 /* Since negative shift count is not well-defined,
6232 don't try to compute it in the compiler. */
6233 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
6235 /* Rewrite an LROTATE_EXPR by a constant into an
6236 RROTATE_EXPR by a new constant. */
6237 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
6239 TREE_SET_CODE (t
, RROTATE_EXPR
);
6240 code
= RROTATE_EXPR
;
6241 TREE_OPERAND (t
, 1) = arg1
6244 convert (TREE_TYPE (arg1
),
6245 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
6247 if (tree_int_cst_sgn (arg1
) < 0)
6251 /* If we have a rotate of a bit operation with the rotate count and
6252 the second operand of the bit operation both constant,
6253 permute the two operations. */
6254 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6255 && (TREE_CODE (arg0
) == BIT_AND_EXPR
6256 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
6257 || TREE_CODE (arg0
) == BIT_IOR_EXPR
6258 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
6259 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6260 return fold (build (TREE_CODE (arg0
), type
,
6261 fold (build (code
, type
,
6262 TREE_OPERAND (arg0
, 0), arg1
)),
6263 fold (build (code
, type
,
6264 TREE_OPERAND (arg0
, 1), arg1
))));
6266 /* Two consecutive rotates adding up to the width of the mode can
6268 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6269 && TREE_CODE (arg0
) == RROTATE_EXPR
6270 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6271 && TREE_INT_CST_HIGH (arg1
) == 0
6272 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
6273 && ((TREE_INT_CST_LOW (arg1
)
6274 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
6275 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
6276 return TREE_OPERAND (arg0
, 0);
6281 if (operand_equal_p (arg0
, arg1
, 0))
6282 return omit_one_operand (type
, arg0
, arg1
);
6283 if (INTEGRAL_TYPE_P (type
)
6284 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
6285 return omit_one_operand (type
, arg1
, arg0
);
6289 if (operand_equal_p (arg0
, arg1
, 0))
6290 return omit_one_operand (type
, arg0
, arg1
);
6291 if (INTEGRAL_TYPE_P (type
)
6292 && TYPE_MAX_VALUE (type
)
6293 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
6294 return omit_one_operand (type
, arg1
, arg0
);
6297 case TRUTH_NOT_EXPR
:
6298 /* Note that the operand of this must be an int
6299 and its values must be 0 or 1.
6300 ("true" is a fixed value perhaps depending on the language,
6301 but we don't handle values other than 1 correctly yet.) */
6302 tem
= invert_truthvalue (arg0
);
6303 /* Avoid infinite recursion. */
6304 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
6306 return convert (type
, tem
);
6308 case TRUTH_ANDIF_EXPR
:
6309 /* Note that the operands of this must be ints
6310 and their values must be 0 or 1.
6311 ("true" is a fixed value perhaps depending on the language.) */
6312 /* If first arg is constant zero, return it. */
6313 if (integer_zerop (arg0
))
6314 return convert (type
, arg0
);
6315 case TRUTH_AND_EXPR
:
6316 /* If either arg is constant true, drop it. */
6317 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6318 return non_lvalue (convert (type
, arg1
));
6319 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6320 /* Preserve sequence points. */
6321 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6322 return non_lvalue (convert (type
, arg0
));
6323 /* If second arg is constant zero, result is zero, but first arg
6324 must be evaluated. */
6325 if (integer_zerop (arg1
))
6326 return omit_one_operand (type
, arg1
, arg0
);
6327 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6328 case will be handled here. */
6329 if (integer_zerop (arg0
))
6330 return omit_one_operand (type
, arg0
, arg1
);
6333 /* We only do these simplifications if we are optimizing. */
6337 /* Check for things like (A || B) && (A || C). We can convert this
6338 to A || (B && C). Note that either operator can be any of the four
6339 truth and/or operations and the transformation will still be
6340 valid. Also note that we only care about order for the
6341 ANDIF and ORIF operators. If B contains side effects, this
6342 might change the truth-value of A. */
6343 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6344 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6345 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6346 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6347 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6348 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6350 tree a00
= TREE_OPERAND (arg0
, 0);
6351 tree a01
= TREE_OPERAND (arg0
, 1);
6352 tree a10
= TREE_OPERAND (arg1
, 0);
6353 tree a11
= TREE_OPERAND (arg1
, 1);
6354 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6355 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6356 && (code
== TRUTH_AND_EXPR
6357 || code
== TRUTH_OR_EXPR
));
6359 if (operand_equal_p (a00
, a10
, 0))
6360 return fold (build (TREE_CODE (arg0
), type
, a00
,
6361 fold (build (code
, type
, a01
, a11
))));
6362 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6363 return fold (build (TREE_CODE (arg0
), type
, a00
,
6364 fold (build (code
, type
, a01
, a10
))));
6365 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6366 return fold (build (TREE_CODE (arg0
), type
, a01
,
6367 fold (build (code
, type
, a00
, a11
))));
6369 /* This case if tricky because we must either have commutative
6370 operators or else A10 must not have side-effects. */
6372 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6373 && operand_equal_p (a01
, a11
, 0))
6374 return fold (build (TREE_CODE (arg0
), type
,
6375 fold (build (code
, type
, a00
, a10
)),
6379 /* See if we can build a range comparison. */
6380 if (0 != (tem
= fold_range_test (t
)))
6383 /* Check for the possibility of merging component references. If our
6384 lhs is another similar operation, try to merge its rhs with our
6385 rhs. Then try to merge our lhs and rhs. */
6386 if (TREE_CODE (arg0
) == code
6387 && 0 != (tem
= fold_truthop (code
, type
,
6388 TREE_OPERAND (arg0
, 1), arg1
)))
6389 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6391 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6396 case TRUTH_ORIF_EXPR
:
6397 /* Note that the operands of this must be ints
6398 and their values must be 0 or true.
6399 ("true" is a fixed value perhaps depending on the language.) */
6400 /* If first arg is constant true, return it. */
6401 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6402 return convert (type
, arg0
);
6404 /* If either arg is constant zero, drop it. */
6405 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6406 return non_lvalue (convert (type
, arg1
));
6407 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6408 /* Preserve sequence points. */
6409 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6410 return non_lvalue (convert (type
, arg0
));
6411 /* If second arg is constant true, result is true, but we must
6412 evaluate first arg. */
6413 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6414 return omit_one_operand (type
, arg1
, arg0
);
6415 /* Likewise for first arg, but note this only occurs here for
6417 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6418 return omit_one_operand (type
, arg0
, arg1
);
6421 case TRUTH_XOR_EXPR
:
6422 /* If either arg is constant zero, drop it. */
6423 if (integer_zerop (arg0
))
6424 return non_lvalue (convert (type
, arg1
));
6425 if (integer_zerop (arg1
))
6426 return non_lvalue (convert (type
, arg0
));
6427 /* If either arg is constant true, this is a logical inversion. */
6428 if (integer_onep (arg0
))
6429 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6430 if (integer_onep (arg1
))
6431 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6440 /* If one arg is a real or integer constant, put it last. */
6441 if ((TREE_CODE (arg0
) == INTEGER_CST
6442 && TREE_CODE (arg1
) != INTEGER_CST
)
6443 || (TREE_CODE (arg0
) == REAL_CST
6444 && TREE_CODE (arg0
) != REAL_CST
))
6446 TREE_OPERAND (t
, 0) = arg1
;
6447 TREE_OPERAND (t
, 1) = arg0
;
6448 arg0
= TREE_OPERAND (t
, 0);
6449 arg1
= TREE_OPERAND (t
, 1);
6450 code
= swap_tree_comparison (code
);
6451 TREE_SET_CODE (t
, code
);
6454 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6456 tree targ0
= strip_float_extensions (arg0
);
6457 tree targ1
= strip_float_extensions (arg1
);
6458 tree newtype
= TREE_TYPE (targ0
);
6460 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
6461 newtype
= TREE_TYPE (targ1
);
6463 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6464 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
6465 return fold (build (code
, type
, convert (newtype
, targ0
),
6466 convert (newtype
, targ1
)));
6468 /* (-a) CMP (-b) -> b CMP a */
6469 if (TREE_CODE (arg0
) == NEGATE_EXPR
6470 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6471 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6472 TREE_OPERAND (arg0
, 0)));
6474 if (TREE_CODE (arg1
) == REAL_CST
)
6476 REAL_VALUE_TYPE cst
;
6477 cst
= TREE_REAL_CST (arg1
);
6479 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6480 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
6482 fold (build (swap_tree_comparison (code
), type
,
6483 TREE_OPERAND (arg0
, 0),
6484 build_real (TREE_TYPE (arg1
),
6485 REAL_VALUE_NEGATE (cst
))));
6487 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6488 /* a CMP (-0) -> a CMP 0 */
6489 if (REAL_VALUE_MINUS_ZERO (cst
))
6490 return fold (build (code
, type
, arg0
,
6491 build_real (TREE_TYPE (arg1
), dconst0
)));
6493 /* x != NaN is always true, other ops are always false. */
6494 if (REAL_VALUE_ISNAN (cst
)
6495 && ! HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg1
))))
6497 t
= (code
== NE_EXPR
) ? integer_one_node
: integer_zero_node
;
6498 return omit_one_operand (type
, convert (type
, t
), arg0
);
6501 /* Fold comparisons against infinity. */
6502 if (REAL_VALUE_ISINF (cst
))
6504 tem
= fold_inf_compare (code
, type
, arg0
, arg1
);
6505 if (tem
!= NULL_TREE
)
6510 /* If this is a comparison of a real constant with a PLUS_EXPR
6511 or a MINUS_EXPR of a real constant, we can convert it into a
6512 comparison with a revised real constant as long as no overflow
6513 occurs when unsafe_math_optimizations are enabled. */
6514 if (flag_unsafe_math_optimizations
6515 && TREE_CODE (arg1
) == REAL_CST
6516 && (TREE_CODE (arg0
) == PLUS_EXPR
6517 || TREE_CODE (arg0
) == MINUS_EXPR
)
6518 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6519 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6520 ? MINUS_EXPR
: PLUS_EXPR
,
6521 arg1
, TREE_OPERAND (arg0
, 1), 0))
6522 && ! TREE_CONSTANT_OVERFLOW (tem
))
6523 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6525 /* Likewise, we can simplify a comparison of a real constant with
6526 a MINUS_EXPR whose first operand is also a real constant, i.e.
6527 (c1 - x) < c2 becomes x > c1-c2. */
6528 if (flag_unsafe_math_optimizations
6529 && TREE_CODE (arg1
) == REAL_CST
6530 && TREE_CODE (arg0
) == MINUS_EXPR
6531 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == REAL_CST
6532 && 0 != (tem
= const_binop (MINUS_EXPR
, TREE_OPERAND (arg0
, 0),
6534 && ! TREE_CONSTANT_OVERFLOW (tem
))
6535 return fold (build (swap_tree_comparison (code
), type
,
6536 TREE_OPERAND (arg0
, 1), tem
));
6538 /* Fold comparisons against built-in math functions. */
6539 if (TREE_CODE (arg1
) == REAL_CST
6540 && flag_unsafe_math_optimizations
6541 && ! flag_errno_math
)
6543 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
6545 if (fcode
!= END_BUILTINS
)
6547 tem
= fold_mathfn_compare (fcode
, code
, type
, arg0
, arg1
);
6548 if (tem
!= NULL_TREE
)
6554 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6555 First, see if one arg is constant; find the constant arg
6556 and the other one. */
6558 tree constop
= 0, varop
= NULL_TREE
;
6559 int constopnum
= -1;
6561 if (TREE_CONSTANT (arg1
))
6562 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6563 if (TREE_CONSTANT (arg0
))
6564 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6566 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6568 /* This optimization is invalid for ordered comparisons
6569 if CONST+INCR overflows or if foo+incr might overflow.
6570 This optimization is invalid for floating point due to rounding.
6571 For pointer types we assume overflow doesn't happen. */
6572 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6573 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6574 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6577 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6578 constop
, TREE_OPERAND (varop
, 1)));
6580 /* Do not overwrite the current varop to be a preincrement,
6581 create a new node so that we won't confuse our caller who
6582 might create trees and throw them away, reusing the
6583 arguments that they passed to build. This shows up in
6584 the THEN or ELSE parts of ?: being postincrements. */
6585 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6586 TREE_OPERAND (varop
, 0),
6587 TREE_OPERAND (varop
, 1));
6589 /* If VAROP is a reference to a bitfield, we must mask
6590 the constant by the width of the field. */
6591 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6592 && DECL_BIT_FIELD(TREE_OPERAND
6593 (TREE_OPERAND (varop
, 0), 1)))
6596 = TREE_INT_CST_LOW (DECL_SIZE
6598 (TREE_OPERAND (varop
, 0), 1)));
6599 tree mask
, unsigned_type
;
6600 unsigned int precision
;
6601 tree folded_compare
;
6603 /* First check whether the comparison would come out
6604 always the same. If we don't do that we would
6605 change the meaning with the masking. */
6606 if (constopnum
== 0)
6607 folded_compare
= fold (build (code
, type
, constop
,
6608 TREE_OPERAND (varop
, 0)));
6610 folded_compare
= fold (build (code
, type
,
6611 TREE_OPERAND (varop
, 0),
6613 if (integer_zerop (folded_compare
)
6614 || integer_onep (folded_compare
))
6615 return omit_one_operand (type
, folded_compare
, varop
);
6617 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6618 precision
= TYPE_PRECISION (unsigned_type
);
6619 mask
= build_int_2 (~0, ~0);
6620 TREE_TYPE (mask
) = unsigned_type
;
6621 force_fit_type (mask
, 0);
6622 mask
= const_binop (RSHIFT_EXPR
, mask
,
6623 size_int (precision
- size
), 0);
6624 newconst
= fold (build (BIT_AND_EXPR
,
6625 TREE_TYPE (varop
), newconst
,
6626 convert (TREE_TYPE (varop
),
6630 t
= build (code
, type
,
6631 (constopnum
== 0) ? newconst
: varop
,
6632 (constopnum
== 1) ? newconst
: varop
);
6636 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6638 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6639 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6640 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6643 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6644 constop
, TREE_OPERAND (varop
, 1)));
6646 /* Do not overwrite the current varop to be a predecrement,
6647 create a new node so that we won't confuse our caller who
6648 might create trees and throw them away, reusing the
6649 arguments that they passed to build. This shows up in
6650 the THEN or ELSE parts of ?: being postdecrements. */
6651 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6652 TREE_OPERAND (varop
, 0),
6653 TREE_OPERAND (varop
, 1));
6655 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6656 && DECL_BIT_FIELD(TREE_OPERAND
6657 (TREE_OPERAND (varop
, 0), 1)))
6660 = TREE_INT_CST_LOW (DECL_SIZE
6662 (TREE_OPERAND (varop
, 0), 1)));
6663 tree mask
, unsigned_type
;
6664 unsigned int precision
;
6665 tree folded_compare
;
6667 if (constopnum
== 0)
6668 folded_compare
= fold (build (code
, type
, constop
,
6669 TREE_OPERAND (varop
, 0)));
6671 folded_compare
= fold (build (code
, type
,
6672 TREE_OPERAND (varop
, 0),
6674 if (integer_zerop (folded_compare
)
6675 || integer_onep (folded_compare
))
6676 return omit_one_operand (type
, folded_compare
, varop
);
6678 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6679 precision
= TYPE_PRECISION (unsigned_type
);
6680 mask
= build_int_2 (~0, ~0);
6681 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6682 force_fit_type (mask
, 0);
6683 mask
= const_binop (RSHIFT_EXPR
, mask
,
6684 size_int (precision
- size
), 0);
6685 newconst
= fold (build (BIT_AND_EXPR
,
6686 TREE_TYPE (varop
), newconst
,
6687 convert (TREE_TYPE (varop
),
6691 t
= build (code
, type
,
6692 (constopnum
== 0) ? newconst
: varop
,
6693 (constopnum
== 1) ? newconst
: varop
);
6699 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6700 This transformation affects the cases which are handled in later
6701 optimizations involving comparisons with non-negative constants. */
6702 if (TREE_CODE (arg1
) == INTEGER_CST
6703 && TREE_CODE (arg0
) != INTEGER_CST
6704 && tree_int_cst_sgn (arg1
) > 0)
6710 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6711 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6716 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6717 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6725 /* Comparisons with the highest or lowest possible integer of
6726 the specified size will have known values. */
6728 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6730 if (TREE_CODE (arg1
) == INTEGER_CST
6731 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6732 && width
<= HOST_BITS_PER_WIDE_INT
6733 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6734 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6736 unsigned HOST_WIDE_INT signed_max
;
6737 unsigned HOST_WIDE_INT max
, min
;
6739 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
6741 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6743 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
6749 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
6752 if (TREE_INT_CST_HIGH (arg1
) == 0
6753 && TREE_INT_CST_LOW (arg1
) == max
)
6757 return omit_one_operand (type
,
6758 convert (type
, integer_zero_node
),
6762 TREE_SET_CODE (t
, EQ_EXPR
);
6765 return omit_one_operand (type
,
6766 convert (type
, integer_one_node
),
6770 TREE_SET_CODE (t
, NE_EXPR
);
6773 /* The GE_EXPR and LT_EXPR cases above are not normally
6774 reached because of previous transformations. */
6779 else if (TREE_INT_CST_HIGH (arg1
) == 0
6780 && TREE_INT_CST_LOW (arg1
) == max
- 1)
6785 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6786 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6790 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6791 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6796 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6797 && TREE_INT_CST_LOW (arg1
) == min
)
6801 return omit_one_operand (type
,
6802 convert (type
, integer_zero_node
),
6806 TREE_SET_CODE (t
, EQ_EXPR
);
6810 return omit_one_operand (type
,
6811 convert (type
, integer_one_node
),
6815 TREE_SET_CODE (t
, NE_EXPR
);
6821 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6822 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
6827 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6828 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6832 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6833 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6839 else if (TREE_INT_CST_HIGH (arg1
) == 0
6840 && TREE_INT_CST_LOW (arg1
) == signed_max
6841 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6842 /* signed_type does not work on pointer types. */
6843 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6845 /* The following case also applies to X < signed_max+1
6846 and X >= signed_max+1 because previous transformations. */
6847 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6850 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
6851 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
6853 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
6854 type
, convert (st0
, arg0
),
6855 convert (st1
, integer_zero_node
)));
6861 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6862 a MINUS_EXPR of a constant, we can convert it into a comparison with
6863 a revised constant as long as no overflow occurs. */
6864 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6865 && TREE_CODE (arg1
) == INTEGER_CST
6866 && (TREE_CODE (arg0
) == PLUS_EXPR
6867 || TREE_CODE (arg0
) == MINUS_EXPR
)
6868 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6869 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6870 ? MINUS_EXPR
: PLUS_EXPR
,
6871 arg1
, TREE_OPERAND (arg0
, 1), 0))
6872 && ! TREE_CONSTANT_OVERFLOW (tem
))
6873 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6875 /* Similarly for a NEGATE_EXPR. */
6876 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6877 && TREE_CODE (arg0
) == NEGATE_EXPR
6878 && TREE_CODE (arg1
) == INTEGER_CST
6879 && 0 != (tem
= negate_expr (arg1
))
6880 && TREE_CODE (tem
) == INTEGER_CST
6881 && ! TREE_CONSTANT_OVERFLOW (tem
))
6882 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6884 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6885 for !=. Don't do this for ordered comparisons due to overflow. */
6886 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6887 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6888 return fold (build (code
, type
,
6889 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6891 /* If we are widening one operand of an integer comparison,
6892 see if the other operand is similarly being widened. Perhaps we
6893 can do the comparison in the narrower type. */
6894 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6895 && TREE_CODE (arg0
) == NOP_EXPR
6896 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6897 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6898 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6899 || (TREE_CODE (t1
) == INTEGER_CST
6900 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6901 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6903 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6904 constant, we can simplify it. */
6905 else if (TREE_CODE (arg1
) == INTEGER_CST
6906 && (TREE_CODE (arg0
) == MIN_EXPR
6907 || TREE_CODE (arg0
) == MAX_EXPR
)
6908 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6909 return optimize_minmax_comparison (t
);
6911 /* If we are comparing an ABS_EXPR with a constant, we can
6912 convert all the cases into explicit comparisons, but they may
6913 well not be faster than doing the ABS and one comparison.
6914 But ABS (X) <= C is a range comparison, which becomes a subtraction
6915 and a comparison, and is probably faster. */
6916 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6917 && TREE_CODE (arg0
) == ABS_EXPR
6918 && ! TREE_SIDE_EFFECTS (arg0
)
6919 && (0 != (tem
= negate_expr (arg1
)))
6920 && TREE_CODE (tem
) == INTEGER_CST
6921 && ! TREE_CONSTANT_OVERFLOW (tem
))
6922 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6923 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6924 build (LE_EXPR
, type
,
6925 TREE_OPERAND (arg0
, 0), arg1
)));
6927 /* If this is an EQ or NE comparison with zero and ARG0 is
6928 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6929 two operations, but the latter can be done in one less insn
6930 on machines that have only two-operand insns or on which a
6931 constant cannot be the first operand. */
6932 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6933 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6935 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6936 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6938 fold (build (code
, type
,
6939 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6941 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6942 TREE_OPERAND (arg0
, 1),
6943 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6944 convert (TREE_TYPE (arg0
),
6947 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6948 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6950 fold (build (code
, type
,
6951 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6953 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6954 TREE_OPERAND (arg0
, 0),
6955 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6956 convert (TREE_TYPE (arg0
),
6961 /* If this is an NE or EQ comparison of zero against the result of a
6962 signed MOD operation whose second operand is a power of 2, make
6963 the MOD operation unsigned since it is simpler and equivalent. */
6964 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6965 && integer_zerop (arg1
)
6966 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6967 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6968 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6969 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6970 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6971 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6973 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
6974 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6975 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6976 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6978 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6981 /* If this is an NE comparison of zero with an AND of one, remove the
6982 comparison since the AND will give the correct value. */
6983 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6984 && TREE_CODE (arg0
) == BIT_AND_EXPR
6985 && integer_onep (TREE_OPERAND (arg0
, 1)))
6986 return convert (type
, arg0
);
6988 /* If we have (A & C) == C where C is a power of 2, convert this into
6989 (A & C) != 0. Similarly for NE_EXPR. */
6990 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6991 && TREE_CODE (arg0
) == BIT_AND_EXPR
6992 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6993 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6994 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6995 arg0
, integer_zero_node
));
6997 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6998 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6999 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7000 && TREE_CODE (arg0
) == BIT_AND_EXPR
7001 && integer_zerop (arg1
))
7003 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0),
7004 TREE_OPERAND (arg0
, 1));
7005 if (arg00
!= NULL_TREE
)
7007 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
7008 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, type
,
7009 convert (stype
, arg00
),
7010 convert (stype
, integer_zero_node
)));
7014 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
7015 and similarly for >= into !=. */
7016 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7017 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7018 && TREE_CODE (arg1
) == LSHIFT_EXPR
7019 && integer_onep (TREE_OPERAND (arg1
, 0)))
7020 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7021 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7022 TREE_OPERAND (arg1
, 1)),
7023 convert (TREE_TYPE (arg0
), integer_zero_node
));
7025 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
7026 && TREE_UNSIGNED (TREE_TYPE (arg0
))
7027 && (TREE_CODE (arg1
) == NOP_EXPR
7028 || TREE_CODE (arg1
) == CONVERT_EXPR
)
7029 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
7030 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
7032 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
7033 convert (TREE_TYPE (arg0
),
7034 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
7035 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
7036 convert (TREE_TYPE (arg0
), integer_zero_node
));
7038 /* Simplify comparison of something with itself. (For IEEE
7039 floating-point, we can only do some of these simplifications.) */
7040 if (operand_equal_p (arg0
, arg1
, 0))
7047 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
)))
7048 return constant_boolean_node (1, type
);
7050 TREE_SET_CODE (t
, code
);
7054 /* For NE, we can only do this simplification if integer. */
7055 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
7057 /* ... fall through ... */
7060 return constant_boolean_node (0, type
);
7066 /* If we are comparing an expression that just has comparisons
7067 of two integer values, arithmetic expressions of those comparisons,
7068 and constants, we can simplify it. There are only three cases
7069 to check: the two values can either be equal, the first can be
7070 greater, or the second can be greater. Fold the expression for
7071 those three values. Since each value must be 0 or 1, we have
7072 eight possibilities, each of which corresponds to the constant 0
7073 or 1 or one of the six possible comparisons.
7075 This handles common cases like (a > b) == 0 but also handles
7076 expressions like ((x > y) - (y > x)) > 0, which supposedly
7077 occur in macroized code. */
7079 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
7081 tree cval1
= 0, cval2
= 0;
7084 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
7085 /* Don't handle degenerate cases here; they should already
7086 have been handled anyway. */
7087 && cval1
!= 0 && cval2
!= 0
7088 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
7089 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
7090 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
7091 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
7092 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
7093 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
7094 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
7096 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
7097 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
7099 /* We can't just pass T to eval_subst in case cval1 or cval2
7100 was the same as ARG1. */
7103 = fold (build (code
, type
,
7104 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
7107 = fold (build (code
, type
,
7108 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
7111 = fold (build (code
, type
,
7112 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
7115 /* All three of these results should be 0 or 1. Confirm they
7116 are. Then use those values to select the proper code
7119 if ((integer_zerop (high_result
)
7120 || integer_onep (high_result
))
7121 && (integer_zerop (equal_result
)
7122 || integer_onep (equal_result
))
7123 && (integer_zerop (low_result
)
7124 || integer_onep (low_result
)))
7126 /* Make a 3-bit mask with the high-order bit being the
7127 value for `>', the next for '=', and the low for '<'. */
7128 switch ((integer_onep (high_result
) * 4)
7129 + (integer_onep (equal_result
) * 2)
7130 + integer_onep (low_result
))
7134 return omit_one_operand (type
, integer_zero_node
, arg0
);
7155 return omit_one_operand (type
, integer_one_node
, arg0
);
7158 t
= build (code
, type
, cval1
, cval2
);
7160 return save_expr (t
);
7167 /* If this is a comparison of a field, we may be able to simplify it. */
7168 if (((TREE_CODE (arg0
) == COMPONENT_REF
7169 && (*lang_hooks
.can_use_bit_fields_p
) ())
7170 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
7171 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
7172 /* Handle the constant case even without -O
7173 to make sure the warnings are given. */
7174 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
7176 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
7180 /* If this is a comparison of complex values and either or both sides
7181 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
7182 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
7183 This may prevent needless evaluations. */
7184 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7185 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
7186 && (TREE_CODE (arg0
) == COMPLEX_EXPR
7187 || TREE_CODE (arg1
) == COMPLEX_EXPR
7188 || TREE_CODE (arg0
) == COMPLEX_CST
7189 || TREE_CODE (arg1
) == COMPLEX_CST
))
7191 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
7192 tree real0
, imag0
, real1
, imag1
;
7194 arg0
= save_expr (arg0
);
7195 arg1
= save_expr (arg1
);
7196 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
7197 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
7198 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
7199 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
7201 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
7204 fold (build (code
, type
, real0
, real1
)),
7205 fold (build (code
, type
, imag0
, imag1
))));
7208 /* Optimize comparisons of strlen vs zero to a compare of the
7209 first character of the string vs zero. To wit,
7210 strlen(ptr) == 0 => *ptr == 0
7211 strlen(ptr) != 0 => *ptr != 0
7212 Other cases should reduce to one of these two (or a constant)
7213 due to the return value of strlen being unsigned. */
7214 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
7215 && integer_zerop (arg1
)
7216 && TREE_CODE (arg0
) == CALL_EXPR
7217 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
7219 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
7222 if (TREE_CODE (fndecl
) == FUNCTION_DECL
7223 && DECL_BUILT_IN (fndecl
)
7224 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
7225 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
7226 && (arglist
= TREE_OPERAND (arg0
, 1))
7227 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
7228 && ! TREE_CHAIN (arglist
))
7229 return fold (build (code
, type
,
7230 build1 (INDIRECT_REF
, char_type_node
,
7231 TREE_VALUE(arglist
)),
7232 integer_zero_node
));
7235 /* From here on, the only cases we handle are when the result is
7236 known to be a constant.
7238 To compute GT, swap the arguments and do LT.
7239 To compute GE, do LT and invert the result.
7240 To compute LE, swap the arguments, do LT and invert the result.
7241 To compute NE, do EQ and invert the result.
7243 Therefore, the code below must handle only EQ and LT. */
7245 if (code
== LE_EXPR
|| code
== GT_EXPR
)
7247 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
7248 code
= swap_tree_comparison (code
);
7251 /* Note that it is safe to invert for real values here because we
7252 will check below in the one case that it matters. */
7256 if (code
== NE_EXPR
|| code
== GE_EXPR
)
7259 code
= invert_tree_comparison (code
);
7262 /* Compute a result for LT or EQ if args permit;
7263 otherwise return T. */
7264 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
7266 if (code
== EQ_EXPR
)
7267 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
7269 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
7270 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
7271 : INT_CST_LT (arg0
, arg1
)),
7275 #if 0 /* This is no longer useful, but breaks some real code. */
7276 /* Assume a nonexplicit constant cannot equal an explicit one,
7277 since such code would be undefined anyway.
7278 Exception: on sysvr4, using #pragma weak,
7279 a label can come out as 0. */
7280 else if (TREE_CODE (arg1
) == INTEGER_CST
7281 && !integer_zerop (arg1
)
7282 && TREE_CONSTANT (arg0
)
7283 && TREE_CODE (arg0
) == ADDR_EXPR
7285 t1
= build_int_2 (0, 0);
7287 /* Two real constants can be compared explicitly. */
7288 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
7290 /* If either operand is a NaN, the result is false with two
7291 exceptions: First, an NE_EXPR is true on NaNs, but that case
7292 is already handled correctly since we will be inverting the
7293 result for NE_EXPR. Second, if we had inverted a LE_EXPR
7294 or a GE_EXPR into a LT_EXPR, we must return true so that it
7295 will be inverted into false. */
7297 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
7298 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
7299 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
7301 else if (code
== EQ_EXPR
)
7302 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
7303 TREE_REAL_CST (arg1
)),
7306 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
7307 TREE_REAL_CST (arg1
)),
7311 if (t1
== NULL_TREE
)
7315 TREE_INT_CST_LOW (t1
) ^= 1;
7317 TREE_TYPE (t1
) = type
;
7318 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
7319 return (*lang_hooks
.truthvalue_conversion
) (t1
);
7323 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
7324 so all simple results must be passed through pedantic_non_lvalue. */
7325 if (TREE_CODE (arg0
) == INTEGER_CST
)
7326 return pedantic_non_lvalue
7327 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
7328 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
7329 return pedantic_omit_one_operand (type
, arg1
, arg0
);
7331 /* If the second operand is zero, invert the comparison and swap
7332 the second and third operands. Likewise if the second operand
7333 is constant and the third is not or if the third operand is
7334 equivalent to the first operand of the comparison. */
7336 if (integer_zerop (arg1
)
7337 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
7338 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7339 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7340 TREE_OPERAND (t
, 2),
7341 TREE_OPERAND (arg0
, 1))))
7343 /* See if this can be inverted. If it can't, possibly because
7344 it was a floating-point inequality comparison, don't do
7346 tem
= invert_truthvalue (arg0
);
7348 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7350 t
= build (code
, type
, tem
,
7351 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7353 /* arg1 should be the first argument of the new T. */
7354 arg1
= TREE_OPERAND (t
, 1);
7359 /* If we have A op B ? A : C, we may be able to convert this to a
7360 simpler expression, depending on the operation and the values
7361 of B and C. Signed zeros prevent all of these transformations,
7362 for reasons given above each one. */
7364 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7365 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7366 arg1
, TREE_OPERAND (arg0
, 1))
7367 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
7369 tree arg2
= TREE_OPERAND (t
, 2);
7370 enum tree_code comp_code
= TREE_CODE (arg0
);
7374 /* If we have A op 0 ? A : -A, consider applying the following
7377 A == 0? A : -A same as -A
7378 A != 0? A : -A same as A
7379 A >= 0? A : -A same as abs (A)
7380 A > 0? A : -A same as abs (A)
7381 A <= 0? A : -A same as -abs (A)
7382 A < 0? A : -A same as -abs (A)
7384 None of these transformations work for modes with signed
7385 zeros. If A is +/-0, the first two transformations will
7386 change the sign of the result (from +0 to -0, or vice
7387 versa). The last four will fix the sign of the result,
7388 even though the original expressions could be positive or
7389 negative, depending on the sign of A.
7391 Note that all these transformations are correct if A is
7392 NaN, since the two alternatives (A and -A) are also NaNs. */
7393 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7394 ? real_zerop (TREE_OPERAND (arg0
, 1))
7395 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7396 && TREE_CODE (arg2
) == NEGATE_EXPR
7397 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7405 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7408 return pedantic_non_lvalue (convert (type
, arg1
));
7411 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7412 arg1
= convert ((*lang_hooks
.types
.signed_type
)
7413 (TREE_TYPE (arg1
)), arg1
);
7414 return pedantic_non_lvalue
7415 (convert (type
, fold (build1 (ABS_EXPR
,
7416 TREE_TYPE (arg1
), arg1
))));
7419 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7420 arg1
= convert ((lang_hooks
.types
.signed_type
)
7421 (TREE_TYPE (arg1
)), arg1
);
7422 return pedantic_non_lvalue
7423 (negate_expr (convert (type
,
7424 fold (build1 (ABS_EXPR
,
7431 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7432 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7433 both transformations are correct when A is NaN: A != 0
7434 is then true, and A == 0 is false. */
7436 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7438 if (comp_code
== NE_EXPR
)
7439 return pedantic_non_lvalue (convert (type
, arg1
));
7440 else if (comp_code
== EQ_EXPR
)
7441 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7444 /* Try some transformations of A op B ? A : B.
7446 A == B? A : B same as B
7447 A != B? A : B same as A
7448 A >= B? A : B same as max (A, B)
7449 A > B? A : B same as max (B, A)
7450 A <= B? A : B same as min (A, B)
7451 A < B? A : B same as min (B, A)
7453 As above, these transformations don't work in the presence
7454 of signed zeros. For example, if A and B are zeros of
7455 opposite sign, the first two transformations will change
7456 the sign of the result. In the last four, the original
7457 expressions give different results for (A=+0, B=-0) and
7458 (A=-0, B=+0), but the transformed expressions do not.
7460 The first two transformations are correct if either A or B
7461 is a NaN. In the first transformation, the condition will
7462 be false, and B will indeed be chosen. In the case of the
7463 second transformation, the condition A != B will be true,
7464 and A will be chosen.
7466 The conversions to max() and min() are not correct if B is
7467 a number and A is not. The conditions in the original
7468 expressions will be false, so all four give B. The min()
7469 and max() versions would give a NaN instead. */
7470 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7471 arg2
, TREE_OPERAND (arg0
, 0)))
7473 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7474 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7475 tree comp_type
= TREE_TYPE (comp_op0
);
7477 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7478 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7488 return pedantic_non_lvalue (convert (type
, arg2
));
7490 return pedantic_non_lvalue (convert (type
, arg1
));
7493 /* In C++ a ?: expression can be an lvalue, so put the
7494 operand which will be used if they are equal first
7495 so that we can convert this back to the
7496 corresponding COND_EXPR. */
7497 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7498 return pedantic_non_lvalue
7499 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7500 (comp_code
== LE_EXPR
7501 ? comp_op0
: comp_op1
),
7502 (comp_code
== LE_EXPR
7503 ? comp_op1
: comp_op0
)))));
7507 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7508 return pedantic_non_lvalue
7509 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7510 (comp_code
== GE_EXPR
7511 ? comp_op0
: comp_op1
),
7512 (comp_code
== GE_EXPR
7513 ? comp_op1
: comp_op0
)))));
7520 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7521 we might still be able to simplify this. For example,
7522 if C1 is one less or one more than C2, this might have started
7523 out as a MIN or MAX and been transformed by this function.
7524 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7526 if (INTEGRAL_TYPE_P (type
)
7527 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7528 && TREE_CODE (arg2
) == INTEGER_CST
)
7532 /* We can replace A with C1 in this case. */
7533 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7534 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7535 TREE_OPERAND (t
, 2));
7539 /* If C1 is C2 + 1, this is min(A, C2). */
7540 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7541 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7542 const_binop (PLUS_EXPR
, arg2
,
7543 integer_one_node
, 0), 1))
7544 return pedantic_non_lvalue
7545 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7549 /* If C1 is C2 - 1, this is min(A, C2). */
7550 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7551 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7552 const_binop (MINUS_EXPR
, arg2
,
7553 integer_one_node
, 0), 1))
7554 return pedantic_non_lvalue
7555 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7559 /* If C1 is C2 - 1, this is max(A, C2). */
7560 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7561 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7562 const_binop (MINUS_EXPR
, arg2
,
7563 integer_one_node
, 0), 1))
7564 return pedantic_non_lvalue
7565 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7569 /* If C1 is C2 + 1, this is max(A, C2). */
7570 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7571 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7572 const_binop (PLUS_EXPR
, arg2
,
7573 integer_one_node
, 0), 1))
7574 return pedantic_non_lvalue
7575 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7584 /* If the second operand is simpler than the third, swap them
7585 since that produces better jump optimization results. */
7586 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7587 || TREE_CODE (arg1
) == SAVE_EXPR
)
7588 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7589 || DECL_P (TREE_OPERAND (t
, 2))
7590 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7592 /* See if this can be inverted. If it can't, possibly because
7593 it was a floating-point inequality comparison, don't do
7595 tem
= invert_truthvalue (arg0
);
7597 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7599 t
= build (code
, type
, tem
,
7600 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7602 /* arg1 should be the first argument of the new T. */
7603 arg1
= TREE_OPERAND (t
, 1);
7608 /* Convert A ? 1 : 0 to simply A. */
7609 if (integer_onep (TREE_OPERAND (t
, 1))
7610 && integer_zerop (TREE_OPERAND (t
, 2))
7611 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7612 call to fold will try to move the conversion inside
7613 a COND, which will recurse. In that case, the COND_EXPR
7614 is probably the best choice, so leave it alone. */
7615 && type
== TREE_TYPE (arg0
))
7616 return pedantic_non_lvalue (arg0
);
7618 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7619 over COND_EXPR in cases such as floating point comparisons. */
7620 if (integer_zerop (TREE_OPERAND (t
, 1))
7621 && integer_onep (TREE_OPERAND (t
, 2))
7622 && truth_value_p (TREE_CODE (arg0
)))
7623 return pedantic_non_lvalue (convert (type
,
7624 invert_truthvalue (arg0
)));
7626 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7627 operation is simply A & 2. */
7629 if (integer_zerop (TREE_OPERAND (t
, 2))
7630 && TREE_CODE (arg0
) == NE_EXPR
7631 && integer_zerop (TREE_OPERAND (arg0
, 1))
7632 && integer_pow2p (arg1
)
7633 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7634 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7636 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7638 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7639 if (integer_zerop (TREE_OPERAND (t
, 2))
7640 && truth_value_p (TREE_CODE (arg0
))
7641 && truth_value_p (TREE_CODE (arg1
)))
7642 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
7645 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7646 if (integer_onep (TREE_OPERAND (t
, 2))
7647 && truth_value_p (TREE_CODE (arg0
))
7648 && truth_value_p (TREE_CODE (arg1
)))
7650 /* Only perform transformation if ARG0 is easily inverted. */
7651 tem
= invert_truthvalue (arg0
);
7652 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7653 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
7660 /* When pedantic, a compound expression can be neither an lvalue
7661 nor an integer constant expression. */
7662 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7664 /* Don't let (0, 0) be null pointer constant. */
7665 if (integer_zerop (arg1
))
7666 return build1 (NOP_EXPR
, type
, arg1
);
7667 return convert (type
, arg1
);
7671 return build_complex (type
, arg0
, arg1
);
7675 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7677 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7678 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7679 TREE_OPERAND (arg0
, 1));
7680 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7681 return TREE_REALPART (arg0
);
7682 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7683 return fold (build (TREE_CODE (arg0
), type
,
7684 fold (build1 (REALPART_EXPR
, type
,
7685 TREE_OPERAND (arg0
, 0))),
7686 fold (build1 (REALPART_EXPR
,
7687 type
, TREE_OPERAND (arg0
, 1)))));
7691 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7692 return convert (type
, integer_zero_node
);
7693 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7694 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7695 TREE_OPERAND (arg0
, 0));
7696 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7697 return TREE_IMAGPART (arg0
);
7698 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7699 return fold (build (TREE_CODE (arg0
), type
,
7700 fold (build1 (IMAGPART_EXPR
, type
,
7701 TREE_OPERAND (arg0
, 0))),
7702 fold (build1 (IMAGPART_EXPR
, type
,
7703 TREE_OPERAND (arg0
, 1)))));
7706 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7708 case CLEANUP_POINT_EXPR
:
7709 if (! has_cleanups (arg0
))
7710 return TREE_OPERAND (t
, 0);
7713 enum tree_code code0
= TREE_CODE (arg0
);
7714 int kind0
= TREE_CODE_CLASS (code0
);
7715 tree arg00
= TREE_OPERAND (arg0
, 0);
7718 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7719 return fold (build1 (code0
, type
,
7720 fold (build1 (CLEANUP_POINT_EXPR
,
7721 TREE_TYPE (arg00
), arg00
))));
7723 if (kind0
== '<' || kind0
== '2'
7724 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7725 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7726 || code0
== TRUTH_XOR_EXPR
)
7728 arg01
= TREE_OPERAND (arg0
, 1);
7730 if (TREE_CONSTANT (arg00
)
7731 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7732 && ! has_cleanups (arg00
)))
7733 return fold (build (code0
, type
, arg00
,
7734 fold (build1 (CLEANUP_POINT_EXPR
,
7735 TREE_TYPE (arg01
), arg01
))));
7737 if (TREE_CONSTANT (arg01
))
7738 return fold (build (code0
, type
,
7739 fold (build1 (CLEANUP_POINT_EXPR
,
7740 TREE_TYPE (arg00
), arg00
)),
7748 /* Check for a built-in function. */
7749 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7750 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7752 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7754 tree tmp
= fold_builtin (expr
);
7762 } /* switch (code) */
7765 /* Determine if first argument is a multiple of second argument. Return 0 if
7766 it is not, or we cannot easily determined it to be.
7768 An example of the sort of thing we care about (at this point; this routine
7769 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7770 fold cases do now) is discovering that
7772 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7778 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7780 This code also handles discovering that
7782 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7784 is a multiple of 8 so we don't have to worry about dealing with a
7787 Note that we *look* inside a SAVE_EXPR only to determine how it was
7788 calculated; it is not safe for fold to do much of anything else with the
7789 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7790 at run time. For example, the latter example above *cannot* be implemented
7791 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7792 evaluation time of the original SAVE_EXPR is not necessarily the same at
7793 the time the new expression is evaluated. The only optimization of this
7794 sort that would be valid is changing
7796 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7800 SAVE_EXPR (I) * SAVE_EXPR (J)
7802 (where the same SAVE_EXPR (J) is used in the original and the
7803 transformed version). */
7806 multiple_of_p (type
, top
, bottom
)
7811 if (operand_equal_p (top
, bottom
, 0))
7814 if (TREE_CODE (type
) != INTEGER_TYPE
)
7817 switch (TREE_CODE (top
))
7820 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7821 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7825 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7826 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7829 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7833 op1
= TREE_OPERAND (top
, 1);
7834 /* const_binop may not detect overflow correctly,
7835 so check for it explicitly here. */
7836 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7837 > TREE_INT_CST_LOW (op1
)
7838 && TREE_INT_CST_HIGH (op1
) == 0
7839 && 0 != (t1
= convert (type
,
7840 const_binop (LSHIFT_EXPR
, size_one_node
,
7842 && ! TREE_OVERFLOW (t1
))
7843 return multiple_of_p (type
, t1
, bottom
);
7848 /* Can't handle conversions from non-integral or wider integral type. */
7849 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7850 || (TYPE_PRECISION (type
)
7851 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7854 /* .. fall through ... */
7857 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7860 if (TREE_CODE (bottom
) != INTEGER_CST
7861 || (TREE_UNSIGNED (type
)
7862 && (tree_int_cst_sgn (top
) < 0
7863 || tree_int_cst_sgn (bottom
) < 0)))
7865 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7873 /* Return true if `t' is known to be non-negative. */
7876 tree_expr_nonnegative_p (t
)
7879 switch (TREE_CODE (t
))
7889 /* These are undefined at zero. This is true even if
7890 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7891 computing here is a user-visible property. */
7895 return tree_int_cst_sgn (t
) >= 0;
7896 case TRUNC_DIV_EXPR
:
7898 case FLOOR_DIV_EXPR
:
7899 case ROUND_DIV_EXPR
:
7900 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7901 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7902 case TRUNC_MOD_EXPR
:
7904 case FLOOR_MOD_EXPR
:
7905 case ROUND_MOD_EXPR
:
7906 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7908 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
7909 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
7911 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7913 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7914 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7916 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7917 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7919 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7921 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7923 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7924 case NON_LVALUE_EXPR
:
7925 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7927 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
7930 if (truth_value_p (TREE_CODE (t
)))
7931 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7934 /* We don't know sign of `t', so be conservative and return false. */
7939 /* Return true if `r' is known to be non-negative.
7940 Only handles constants at the moment. */
7943 rtl_expr_nonnegative_p (r
)
7946 switch (GET_CODE (r
))
7949 return INTVAL (r
) >= 0;
7952 if (GET_MODE (r
) == VOIDmode
)
7953 return CONST_DOUBLE_HIGH (r
) >= 0;
7961 units
= CONST_VECTOR_NUNITS (r
);
7963 for (i
= 0; i
< units
; ++i
)
7965 elt
= CONST_VECTOR_ELT (r
, i
);
7966 if (!rtl_expr_nonnegative_p (elt
))
7975 /* These are always nonnegative. */
7983 #include "gt-fold-const.h"