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 omit_one_operand
PARAMS ((tree
, tree
, tree
));
85 static tree pedantic_omit_one_operand
PARAMS ((tree
, tree
, tree
));
86 static tree distribute_bit_expr
PARAMS ((enum tree_code
, tree
, tree
, tree
));
87 static tree make_bit_field_ref
PARAMS ((tree
, tree
, int, int, int));
88 static tree optimize_bit_field_compare
PARAMS ((enum tree_code
, tree
,
90 static tree decode_field_reference
PARAMS ((tree
, HOST_WIDE_INT
*,
92 enum machine_mode
*, int *,
93 int *, tree
*, tree
*));
94 static int all_ones_mask_p
PARAMS ((tree
, int));
95 static tree sign_bit_p
PARAMS ((tree
, tree
));
96 static int simple_operand_p
PARAMS ((tree
));
97 static tree range_binop
PARAMS ((enum tree_code
, tree
, tree
, int,
99 static tree make_range
PARAMS ((tree
, int *, tree
*, tree
*));
100 static tree build_range_check
PARAMS ((tree
, tree
, int, tree
, tree
));
101 static int merge_ranges
PARAMS ((int *, tree
*, tree
*, int, tree
, tree
,
103 static tree fold_range_test
PARAMS ((tree
));
104 static tree unextend
PARAMS ((tree
, int, int, tree
));
105 static tree fold_truthop
PARAMS ((enum tree_code
, tree
, tree
, tree
));
106 static tree optimize_minmax_comparison
PARAMS ((tree
));
107 static tree extract_muldiv
PARAMS ((tree
, tree
, enum tree_code
, tree
));
108 static tree extract_muldiv_1
PARAMS ((tree
, tree
, enum tree_code
, tree
));
109 static tree strip_compound_expr
PARAMS ((tree
, tree
));
110 static int multiple_of_p
PARAMS ((tree
, tree
, tree
));
111 static tree constant_boolean_node
PARAMS ((int, tree
));
112 static int count_cond
PARAMS ((tree
, int));
113 static tree fold_binary_op_with_conditional_arg
114 PARAMS ((enum tree_code
, tree
, tree
, tree
, int));
115 static bool fold_real_zero_addition_p
PARAMS ((tree
, tree
, int));
117 /* The following constants represent a bit based encoding of GCC's
118 comparison operators. This encoding simplifies transformations
119 on relational comparison operators, such as AND and OR. */
120 #define COMPCODE_FALSE 0
121 #define COMPCODE_LT 1
122 #define COMPCODE_EQ 2
123 #define COMPCODE_LE 3
124 #define COMPCODE_GT 4
125 #define COMPCODE_NE 5
126 #define COMPCODE_GE 6
127 #define COMPCODE_TRUE 7
129 /* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
130 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
131 and SUM1. Then this yields nonzero if overflow occurred during the
134 Overflow occurs if A and B have the same sign, but A and SUM differ in
135 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
137 #define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
139 /* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
140 We do that by representing the two-word integer in 4 words, with only
141 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
142 number. The value of the word is LOWPART + HIGHPART * BASE. */
145 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
146 #define HIGHPART(x) \
147 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
148 #define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
150 /* Unpack a two-word integer into 4 words.
151 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
152 WORDS points to the array of HOST_WIDE_INTs. */
155 encode (words
, low
, hi
)
156 HOST_WIDE_INT
*words
;
157 unsigned HOST_WIDE_INT low
;
160 words
[0] = LOWPART (low
);
161 words
[1] = HIGHPART (low
);
162 words
[2] = LOWPART (hi
);
163 words
[3] = HIGHPART (hi
);
166 /* Pack an array of 4 words into a two-word integer.
167 WORDS points to the array of words.
168 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
171 decode (words
, low
, hi
)
172 HOST_WIDE_INT
*words
;
173 unsigned HOST_WIDE_INT
*low
;
176 *low
= words
[0] + words
[1] * BASE
;
177 *hi
= words
[2] + words
[3] * BASE
;
180 /* Make the integer constant T valid for its type by setting to 0 or 1 all
181 the bits in the constant that don't belong in the type.
183 Return 1 if a signed overflow occurs, 0 otherwise. If OVERFLOW is
184 nonzero, a signed overflow has already occurred in calculating T, so
188 force_fit_type (t
, overflow
)
192 unsigned HOST_WIDE_INT low
;
196 if (TREE_CODE (t
) == REAL_CST
)
198 /* ??? Used to check for overflow here via CHECK_FLOAT_TYPE.
199 Consider doing it via real_convert now. */
203 else if (TREE_CODE (t
) != INTEGER_CST
)
206 low
= TREE_INT_CST_LOW (t
);
207 high
= TREE_INT_CST_HIGH (t
);
209 if (POINTER_TYPE_P (TREE_TYPE (t
)))
212 prec
= TYPE_PRECISION (TREE_TYPE (t
));
214 /* First clear all bits that are beyond the type's precision. */
216 if (prec
== 2 * HOST_BITS_PER_WIDE_INT
)
218 else if (prec
> HOST_BITS_PER_WIDE_INT
)
219 TREE_INT_CST_HIGH (t
)
220 &= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
223 TREE_INT_CST_HIGH (t
) = 0;
224 if (prec
< HOST_BITS_PER_WIDE_INT
)
225 TREE_INT_CST_LOW (t
) &= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
228 /* Unsigned types do not suffer sign extension or overflow unless they
230 if (TREE_UNSIGNED (TREE_TYPE (t
))
231 && ! (TREE_CODE (TREE_TYPE (t
)) == INTEGER_TYPE
232 && TYPE_IS_SIZETYPE (TREE_TYPE (t
))))
235 /* If the value's sign bit is set, extend the sign. */
236 if (prec
!= 2 * HOST_BITS_PER_WIDE_INT
237 && (prec
> HOST_BITS_PER_WIDE_INT
238 ? 0 != (TREE_INT_CST_HIGH (t
)
240 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)))
241 : 0 != (TREE_INT_CST_LOW (t
)
242 & ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)))))
244 /* Value is negative:
245 set to 1 all the bits that are outside this type's precision. */
246 if (prec
> HOST_BITS_PER_WIDE_INT
)
247 TREE_INT_CST_HIGH (t
)
248 |= ((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
251 TREE_INT_CST_HIGH (t
) = -1;
252 if (prec
< HOST_BITS_PER_WIDE_INT
)
253 TREE_INT_CST_LOW (t
) |= ((unsigned HOST_WIDE_INT
) (-1) << prec
);
257 /* Return nonzero if signed overflow occurred. */
259 ((overflow
| (low
^ TREE_INT_CST_LOW (t
)) | (high
^ TREE_INT_CST_HIGH (t
)))
263 /* Add two doubleword integers with doubleword result.
264 Each argument is given as two `HOST_WIDE_INT' pieces.
265 One argument is L1 and H1; the other, L2 and H2.
266 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
269 add_double (l1
, h1
, l2
, h2
, lv
, hv
)
270 unsigned HOST_WIDE_INT l1
, l2
;
271 HOST_WIDE_INT h1
, h2
;
272 unsigned HOST_WIDE_INT
*lv
;
275 unsigned HOST_WIDE_INT l
;
279 h
= h1
+ h2
+ (l
< l1
);
283 return OVERFLOW_SUM_SIGN (h1
, h2
, h
);
286 /* Negate a doubleword integer with doubleword result.
287 Return nonzero if the operation overflows, assuming it's signed.
288 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
289 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
292 neg_double (l1
, h1
, lv
, hv
)
293 unsigned HOST_WIDE_INT l1
;
295 unsigned HOST_WIDE_INT
*lv
;
302 return (*hv
& h1
) < 0;
312 /* Multiply two doubleword integers with doubleword result.
313 Return nonzero if the operation overflows, assuming it's signed.
314 Each argument is given as two `HOST_WIDE_INT' pieces.
315 One argument is L1 and H1; the other, L2 and H2.
316 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
319 mul_double (l1
, h1
, l2
, h2
, lv
, hv
)
320 unsigned HOST_WIDE_INT l1
, l2
;
321 HOST_WIDE_INT h1
, h2
;
322 unsigned HOST_WIDE_INT
*lv
;
325 HOST_WIDE_INT arg1
[4];
326 HOST_WIDE_INT arg2
[4];
327 HOST_WIDE_INT prod
[4 * 2];
328 unsigned HOST_WIDE_INT carry
;
330 unsigned HOST_WIDE_INT toplow
, neglow
;
331 HOST_WIDE_INT tophigh
, neghigh
;
333 encode (arg1
, l1
, h1
);
334 encode (arg2
, l2
, h2
);
336 memset ((char *) prod
, 0, sizeof prod
);
338 for (i
= 0; i
< 4; i
++)
341 for (j
= 0; j
< 4; j
++)
344 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
345 carry
+= arg1
[i
] * arg2
[j
];
346 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
348 prod
[k
] = LOWPART (carry
);
349 carry
= HIGHPART (carry
);
354 decode (prod
, lv
, hv
); /* This ignores prod[4] through prod[4*2-1] */
356 /* Check for overflow by calculating the top half of the answer in full;
357 it should agree with the low half's sign bit. */
358 decode (prod
+ 4, &toplow
, &tophigh
);
361 neg_double (l2
, h2
, &neglow
, &neghigh
);
362 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
366 neg_double (l1
, h1
, &neglow
, &neghigh
);
367 add_double (neglow
, neghigh
, toplow
, tophigh
, &toplow
, &tophigh
);
369 return (*hv
< 0 ? ~(toplow
& tophigh
) : toplow
| tophigh
) != 0;
372 /* Shift the doubleword integer in L1, H1 left by COUNT places
373 keeping only PREC bits of result.
374 Shift right if COUNT is negative.
375 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
376 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
379 lshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
380 unsigned HOST_WIDE_INT l1
;
381 HOST_WIDE_INT h1
, count
;
383 unsigned HOST_WIDE_INT
*lv
;
387 unsigned HOST_WIDE_INT signmask
;
391 rshift_double (l1
, h1
, -count
, prec
, lv
, hv
, arith
);
395 #ifdef SHIFT_COUNT_TRUNCATED
396 if (SHIFT_COUNT_TRUNCATED
)
400 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
402 /* Shifting by the host word size is undefined according to the
403 ANSI standard, so we must handle this as a special case. */
407 else if (count
>= HOST_BITS_PER_WIDE_INT
)
409 *hv
= l1
<< (count
- HOST_BITS_PER_WIDE_INT
);
414 *hv
= (((unsigned HOST_WIDE_INT
) h1
<< count
)
415 | (l1
>> (HOST_BITS_PER_WIDE_INT
- count
- 1) >> 1));
419 /* Sign extend all bits that are beyond the precision. */
421 signmask
= -((prec
> HOST_BITS_PER_WIDE_INT
422 ? ((unsigned HOST_WIDE_INT
) *hv
423 >> (prec
- HOST_BITS_PER_WIDE_INT
- 1))
424 : (*lv
>> (prec
- 1))) & 1);
426 if (prec
>= 2 * HOST_BITS_PER_WIDE_INT
)
428 else if (prec
>= HOST_BITS_PER_WIDE_INT
)
430 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- HOST_BITS_PER_WIDE_INT
));
431 *hv
|= signmask
<< (prec
- HOST_BITS_PER_WIDE_INT
);
436 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << prec
);
437 *lv
|= signmask
<< prec
;
441 /* Shift the doubleword integer in L1, H1 right by COUNT places
442 keeping only PREC bits of result. COUNT must be positive.
443 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
444 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
447 rshift_double (l1
, h1
, count
, prec
, lv
, hv
, arith
)
448 unsigned HOST_WIDE_INT l1
;
449 HOST_WIDE_INT h1
, count
;
451 unsigned HOST_WIDE_INT
*lv
;
455 unsigned HOST_WIDE_INT signmask
;
458 ? -((unsigned HOST_WIDE_INT
) h1
>> (HOST_BITS_PER_WIDE_INT
- 1))
461 #ifdef SHIFT_COUNT_TRUNCATED
462 if (SHIFT_COUNT_TRUNCATED
)
466 if (count
>= 2 * HOST_BITS_PER_WIDE_INT
)
468 /* Shifting by the host word size is undefined according to the
469 ANSI standard, so we must handle this as a special case. */
473 else if (count
>= HOST_BITS_PER_WIDE_INT
)
476 *lv
= (unsigned HOST_WIDE_INT
) h1
>> (count
- HOST_BITS_PER_WIDE_INT
);
480 *hv
= (unsigned HOST_WIDE_INT
) h1
>> count
;
482 | ((unsigned HOST_WIDE_INT
) h1
<< (HOST_BITS_PER_WIDE_INT
- count
- 1) << 1));
485 /* Zero / sign extend all bits that are beyond the precision. */
487 if (count
>= (HOST_WIDE_INT
)prec
)
492 else if ((prec
- count
) >= 2 * HOST_BITS_PER_WIDE_INT
)
494 else if ((prec
- count
) >= HOST_BITS_PER_WIDE_INT
)
496 *hv
&= ~((HOST_WIDE_INT
) (-1) << (prec
- count
- HOST_BITS_PER_WIDE_INT
));
497 *hv
|= signmask
<< (prec
- count
- HOST_BITS_PER_WIDE_INT
);
502 *lv
&= ~((unsigned HOST_WIDE_INT
) (-1) << (prec
- count
));
503 *lv
|= signmask
<< (prec
- count
);
507 /* Rotate the doubleword integer in L1, H1 left by COUNT places
508 keeping only PREC bits of result.
509 Rotate right if COUNT is negative.
510 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
513 lrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
514 unsigned HOST_WIDE_INT l1
;
515 HOST_WIDE_INT h1
, count
;
517 unsigned HOST_WIDE_INT
*lv
;
520 unsigned HOST_WIDE_INT s1l
, s2l
;
521 HOST_WIDE_INT s1h
, s2h
;
527 lshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
528 rshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
533 /* Rotate the doubleword integer in L1, H1 left by COUNT places
534 keeping only PREC bits of result. COUNT must be positive.
535 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
538 rrotate_double (l1
, h1
, count
, prec
, lv
, hv
)
539 unsigned HOST_WIDE_INT l1
;
540 HOST_WIDE_INT h1
, count
;
542 unsigned HOST_WIDE_INT
*lv
;
545 unsigned HOST_WIDE_INT s1l
, s2l
;
546 HOST_WIDE_INT s1h
, s2h
;
552 rshift_double (l1
, h1
, count
, prec
, &s1l
, &s1h
, 0);
553 lshift_double (l1
, h1
, prec
- count
, prec
, &s2l
, &s2h
, 0);
558 /* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
559 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
560 CODE is a tree code for a kind of division, one of
561 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
563 It controls how the quotient is rounded to an integer.
564 Return nonzero if the operation overflows.
565 UNS nonzero says do unsigned division. */
568 div_and_round_double (code
, uns
,
569 lnum_orig
, hnum_orig
, lden_orig
, hden_orig
,
570 lquo
, hquo
, lrem
, hrem
)
573 unsigned HOST_WIDE_INT lnum_orig
; /* num == numerator == dividend */
574 HOST_WIDE_INT hnum_orig
;
575 unsigned HOST_WIDE_INT lden_orig
; /* den == denominator == divisor */
576 HOST_WIDE_INT hden_orig
;
577 unsigned HOST_WIDE_INT
*lquo
, *lrem
;
578 HOST_WIDE_INT
*hquo
, *hrem
;
581 HOST_WIDE_INT num
[4 + 1]; /* extra element for scaling. */
582 HOST_WIDE_INT den
[4], quo
[4];
584 unsigned HOST_WIDE_INT work
;
585 unsigned HOST_WIDE_INT carry
= 0;
586 unsigned HOST_WIDE_INT lnum
= lnum_orig
;
587 HOST_WIDE_INT hnum
= hnum_orig
;
588 unsigned HOST_WIDE_INT lden
= lden_orig
;
589 HOST_WIDE_INT hden
= hden_orig
;
592 if (hden
== 0 && lden
== 0)
593 overflow
= 1, lden
= 1;
595 /* calculate quotient sign and convert operands to unsigned. */
601 /* (minimum integer) / (-1) is the only overflow case. */
602 if (neg_double (lnum
, hnum
, &lnum
, &hnum
)
603 && ((HOST_WIDE_INT
) lden
& hden
) == -1)
609 neg_double (lden
, hden
, &lden
, &hden
);
613 if (hnum
== 0 && hden
== 0)
614 { /* single precision */
616 /* This unsigned division rounds toward zero. */
622 { /* trivial case: dividend < divisor */
623 /* hden != 0 already checked. */
630 memset ((char *) quo
, 0, sizeof quo
);
632 memset ((char *) num
, 0, sizeof num
); /* to zero 9th element */
633 memset ((char *) den
, 0, sizeof den
);
635 encode (num
, lnum
, hnum
);
636 encode (den
, lden
, hden
);
638 /* Special code for when the divisor < BASE. */
639 if (hden
== 0 && lden
< (unsigned HOST_WIDE_INT
) BASE
)
641 /* hnum != 0 already checked. */
642 for (i
= 4 - 1; i
>= 0; i
--)
644 work
= num
[i
] + carry
* BASE
;
645 quo
[i
] = work
/ lden
;
651 /* Full double precision division,
652 with thanks to Don Knuth's "Seminumerical Algorithms". */
653 int num_hi_sig
, den_hi_sig
;
654 unsigned HOST_WIDE_INT quo_est
, scale
;
656 /* Find the highest nonzero divisor digit. */
657 for (i
= 4 - 1;; i
--)
664 /* Insure that the first digit of the divisor is at least BASE/2.
665 This is required by the quotient digit estimation algorithm. */
667 scale
= BASE
/ (den
[den_hi_sig
] + 1);
669 { /* scale divisor and dividend */
671 for (i
= 0; i
<= 4 - 1; i
++)
673 work
= (num
[i
] * scale
) + carry
;
674 num
[i
] = LOWPART (work
);
675 carry
= HIGHPART (work
);
680 for (i
= 0; i
<= 4 - 1; i
++)
682 work
= (den
[i
] * scale
) + carry
;
683 den
[i
] = LOWPART (work
);
684 carry
= HIGHPART (work
);
685 if (den
[i
] != 0) den_hi_sig
= i
;
692 for (i
= num_hi_sig
- den_hi_sig
- 1; i
>= 0; i
--)
694 /* Guess the next quotient digit, quo_est, by dividing the first
695 two remaining dividend digits by the high order quotient digit.
696 quo_est is never low and is at most 2 high. */
697 unsigned HOST_WIDE_INT tmp
;
699 num_hi_sig
= i
+ den_hi_sig
+ 1;
700 work
= num
[num_hi_sig
] * BASE
+ num
[num_hi_sig
- 1];
701 if (num
[num_hi_sig
] != den
[den_hi_sig
])
702 quo_est
= work
/ den
[den_hi_sig
];
706 /* Refine quo_est so it's usually correct, and at most one high. */
707 tmp
= work
- quo_est
* den
[den_hi_sig
];
709 && (den
[den_hi_sig
- 1] * quo_est
710 > (tmp
* BASE
+ num
[num_hi_sig
- 2])))
713 /* Try QUO_EST as the quotient digit, by multiplying the
714 divisor by QUO_EST and subtracting from the remaining dividend.
715 Keep in mind that QUO_EST is the I - 1st digit. */
718 for (j
= 0; j
<= den_hi_sig
; j
++)
720 work
= quo_est
* den
[j
] + carry
;
721 carry
= HIGHPART (work
);
722 work
= num
[i
+ j
] - LOWPART (work
);
723 num
[i
+ j
] = LOWPART (work
);
724 carry
+= HIGHPART (work
) != 0;
727 /* If quo_est was high by one, then num[i] went negative and
728 we need to correct things. */
729 if (num
[num_hi_sig
] < (HOST_WIDE_INT
) carry
)
732 carry
= 0; /* add divisor back in */
733 for (j
= 0; j
<= den_hi_sig
; j
++)
735 work
= num
[i
+ j
] + den
[j
] + carry
;
736 carry
= HIGHPART (work
);
737 num
[i
+ j
] = LOWPART (work
);
740 num
[num_hi_sig
] += carry
;
743 /* Store the quotient digit. */
748 decode (quo
, lquo
, hquo
);
751 /* if result is negative, make it so. */
753 neg_double (*lquo
, *hquo
, lquo
, hquo
);
755 /* compute trial remainder: rem = num - (quo * den) */
756 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
757 neg_double (*lrem
, *hrem
, lrem
, hrem
);
758 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
763 case TRUNC_MOD_EXPR
: /* round toward zero */
764 case EXACT_DIV_EXPR
: /* for this one, it shouldn't matter */
768 case FLOOR_MOD_EXPR
: /* round toward negative infinity */
769 if (quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio < 0 && rem != 0 */
772 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1,
780 case CEIL_MOD_EXPR
: /* round toward positive infinity */
781 if (!quo_neg
&& (*lrem
!= 0 || *hrem
!= 0)) /* ratio > 0 && rem != 0 */
783 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
791 case ROUND_MOD_EXPR
: /* round to closest integer */
793 unsigned HOST_WIDE_INT labs_rem
= *lrem
;
794 HOST_WIDE_INT habs_rem
= *hrem
;
795 unsigned HOST_WIDE_INT labs_den
= lden
, ltwice
;
796 HOST_WIDE_INT habs_den
= hden
, htwice
;
798 /* Get absolute values */
800 neg_double (*lrem
, *hrem
, &labs_rem
, &habs_rem
);
802 neg_double (lden
, hden
, &labs_den
, &habs_den
);
804 /* If (2 * abs (lrem) >= abs (lden)) */
805 mul_double ((HOST_WIDE_INT
) 2, (HOST_WIDE_INT
) 0,
806 labs_rem
, habs_rem
, <wice
, &htwice
);
808 if (((unsigned HOST_WIDE_INT
) habs_den
809 < (unsigned HOST_WIDE_INT
) htwice
)
810 || (((unsigned HOST_WIDE_INT
) habs_den
811 == (unsigned HOST_WIDE_INT
) htwice
)
812 && (labs_den
< ltwice
)))
816 add_double (*lquo
, *hquo
,
817 (HOST_WIDE_INT
) -1, (HOST_WIDE_INT
) -1, lquo
, hquo
);
820 add_double (*lquo
, *hquo
, (HOST_WIDE_INT
) 1, (HOST_WIDE_INT
) 0,
832 /* compute true remainder: rem = num - (quo * den) */
833 mul_double (*lquo
, *hquo
, lden_orig
, hden_orig
, lrem
, hrem
);
834 neg_double (*lrem
, *hrem
, lrem
, hrem
);
835 add_double (lnum_orig
, hnum_orig
, *lrem
, *hrem
, lrem
, hrem
);
839 /* Determine whether an expression T can be cheaply negated using
840 the function negate_expr. */
846 unsigned HOST_WIDE_INT val
;
853 type
= TREE_TYPE (t
);
856 switch (TREE_CODE (t
))
859 if (TREE_UNSIGNED (type
))
862 /* Check that -CST will not overflow type. */
863 prec
= TYPE_PRECISION (type
);
864 if (prec
> HOST_BITS_PER_WIDE_INT
)
866 if (TREE_INT_CST_LOW (t
) != 0)
868 prec
-= HOST_BITS_PER_WIDE_INT
;
869 val
= TREE_INT_CST_HIGH (t
);
872 val
= TREE_INT_CST_LOW (t
);
873 if (prec
< HOST_BITS_PER_WIDE_INT
)
874 val
&= ((unsigned HOST_WIDE_INT
) 1 << prec
) - 1;
875 return val
!= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1));
888 /* Given T, an expression, return the negation of T. Allow for T to be
889 null, in which case return null. */
901 type
= TREE_TYPE (t
);
904 switch (TREE_CODE (t
))
908 if (! TREE_UNSIGNED (type
)
909 && 0 != (tem
= fold (build1 (NEGATE_EXPR
, type
, t
)))
910 && ! TREE_OVERFLOW (tem
))
915 return convert (type
, TREE_OPERAND (t
, 0));
918 /* - (A - B) -> B - A */
919 if (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
920 return convert (type
,
921 fold (build (MINUS_EXPR
, TREE_TYPE (t
),
923 TREE_OPERAND (t
, 0))));
930 return convert (type
, fold (build1 (NEGATE_EXPR
, TREE_TYPE (t
), t
)));
933 /* Split a tree IN into a constant, literal and variable parts that could be
934 combined with CODE to make IN. "constant" means an expression with
935 TREE_CONSTANT but that isn't an actual constant. CODE must be a
936 commutative arithmetic operation. Store the constant part into *CONP,
937 the literal in *LITP and return the variable part. If a part isn't
938 present, set it to null. If the tree does not decompose in this way,
939 return the entire tree as the variable part and the other parts as null.
941 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
942 case, we negate an operand that was subtracted. Except if it is a
943 literal for which we use *MINUS_LITP instead.
945 If NEGATE_P is true, we are negating all of IN, again except a literal
946 for which we use *MINUS_LITP instead.
948 If IN is itself a literal or constant, return it as appropriate.
950 Note that we do not guarantee that any of the three values will be the
951 same type as IN, but they will have the same signedness and mode. */
954 split_tree (in
, code
, conp
, litp
, minus_litp
, negate_p
)
957 tree
*conp
, *litp
, *minus_litp
;
966 /* Strip any conversions that don't change the machine mode or signedness. */
967 STRIP_SIGN_NOPS (in
);
969 if (TREE_CODE (in
) == INTEGER_CST
|| TREE_CODE (in
) == REAL_CST
)
971 else if (TREE_CODE (in
) == code
972 || (! FLOAT_TYPE_P (TREE_TYPE (in
))
973 /* We can associate addition and subtraction together (even
974 though the C standard doesn't say so) for integers because
975 the value is not affected. For reals, the value might be
976 affected, so we can't. */
977 && ((code
== PLUS_EXPR
&& TREE_CODE (in
) == MINUS_EXPR
)
978 || (code
== MINUS_EXPR
&& TREE_CODE (in
) == PLUS_EXPR
))))
980 tree op0
= TREE_OPERAND (in
, 0);
981 tree op1
= TREE_OPERAND (in
, 1);
982 int neg1_p
= TREE_CODE (in
) == MINUS_EXPR
;
983 int neg_litp_p
= 0, neg_conp_p
= 0, neg_var_p
= 0;
985 /* First see if either of the operands is a literal, then a constant. */
986 if (TREE_CODE (op0
) == INTEGER_CST
|| TREE_CODE (op0
) == REAL_CST
)
987 *litp
= op0
, op0
= 0;
988 else if (TREE_CODE (op1
) == INTEGER_CST
|| TREE_CODE (op1
) == REAL_CST
)
989 *litp
= op1
, neg_litp_p
= neg1_p
, op1
= 0;
991 if (op0
!= 0 && TREE_CONSTANT (op0
))
992 *conp
= op0
, op0
= 0;
993 else if (op1
!= 0 && TREE_CONSTANT (op1
))
994 *conp
= op1
, neg_conp_p
= neg1_p
, op1
= 0;
996 /* If we haven't dealt with either operand, this is not a case we can
997 decompose. Otherwise, VAR is either of the ones remaining, if any. */
998 if (op0
!= 0 && op1
!= 0)
1003 var
= op1
, neg_var_p
= neg1_p
;
1005 /* Now do any needed negations. */
1007 *minus_litp
= *litp
, *litp
= 0;
1009 *conp
= negate_expr (*conp
);
1011 var
= negate_expr (var
);
1013 else if (TREE_CONSTANT (in
))
1021 *minus_litp
= *litp
, *litp
= 0;
1022 else if (*minus_litp
)
1023 *litp
= *minus_litp
, *minus_litp
= 0;
1024 *conp
= negate_expr (*conp
);
1025 var
= negate_expr (var
);
1031 /* Re-associate trees split by the above function. T1 and T2 are either
1032 expressions to associate or null. Return the new expression, if any. If
1033 we build an operation, do it in TYPE and with CODE. */
1036 associate_trees (t1
, t2
, code
, type
)
1038 enum tree_code code
;
1046 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1047 try to fold this since we will have infinite recursion. But do
1048 deal with any NEGATE_EXPRs. */
1049 if (TREE_CODE (t1
) == code
|| TREE_CODE (t2
) == code
1050 || TREE_CODE (t1
) == MINUS_EXPR
|| TREE_CODE (t2
) == MINUS_EXPR
)
1052 if (code
== PLUS_EXPR
)
1054 if (TREE_CODE (t1
) == NEGATE_EXPR
)
1055 return build (MINUS_EXPR
, type
, convert (type
, t2
),
1056 convert (type
, TREE_OPERAND (t1
, 0)));
1057 else if (TREE_CODE (t2
) == NEGATE_EXPR
)
1058 return build (MINUS_EXPR
, type
, convert (type
, t1
),
1059 convert (type
, TREE_OPERAND (t2
, 0)));
1061 return build (code
, type
, convert (type
, t1
), convert (type
, t2
));
1064 return fold (build (code
, type
, convert (type
, t1
), convert (type
, t2
)));
1067 /* Combine two integer constants ARG1 and ARG2 under operation CODE
1068 to produce a new constant.
1070 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1073 int_const_binop (code
, arg1
, arg2
, notrunc
)
1074 enum tree_code code
;
1078 unsigned HOST_WIDE_INT int1l
, int2l
;
1079 HOST_WIDE_INT int1h
, int2h
;
1080 unsigned HOST_WIDE_INT low
;
1082 unsigned HOST_WIDE_INT garbagel
;
1083 HOST_WIDE_INT garbageh
;
1085 tree type
= TREE_TYPE (arg1
);
1086 int uns
= TREE_UNSIGNED (type
);
1088 = (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
));
1090 int no_overflow
= 0;
1092 int1l
= TREE_INT_CST_LOW (arg1
);
1093 int1h
= TREE_INT_CST_HIGH (arg1
);
1094 int2l
= TREE_INT_CST_LOW (arg2
);
1095 int2h
= TREE_INT_CST_HIGH (arg2
);
1100 low
= int1l
| int2l
, hi
= int1h
| int2h
;
1104 low
= int1l
^ int2l
, hi
= int1h
^ int2h
;
1108 low
= int1l
& int2l
, hi
= int1h
& int2h
;
1111 case BIT_ANDTC_EXPR
:
1112 low
= int1l
& ~int2l
, hi
= int1h
& ~int2h
;
1118 /* It's unclear from the C standard whether shifts can overflow.
1119 The following code ignores overflow; perhaps a C standard
1120 interpretation ruling is needed. */
1121 lshift_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1129 lrotate_double (int1l
, int1h
, int2l
, TYPE_PRECISION (type
),
1134 overflow
= add_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1138 neg_double (int2l
, int2h
, &low
, &hi
);
1139 add_double (int1l
, int1h
, low
, hi
, &low
, &hi
);
1140 overflow
= OVERFLOW_SUM_SIGN (hi
, int2h
, int1h
);
1144 overflow
= mul_double (int1l
, int1h
, int2l
, int2h
, &low
, &hi
);
1147 case TRUNC_DIV_EXPR
:
1148 case FLOOR_DIV_EXPR
: case CEIL_DIV_EXPR
:
1149 case EXACT_DIV_EXPR
:
1150 /* This is a shortcut for a common special case. */
1151 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1152 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1153 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1154 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1156 if (code
== CEIL_DIV_EXPR
)
1159 low
= int1l
/ int2l
, hi
= 0;
1163 /* ... fall through ... */
1165 case ROUND_DIV_EXPR
:
1166 if (int2h
== 0 && int2l
== 1)
1168 low
= int1l
, hi
= int1h
;
1171 if (int1l
== int2l
&& int1h
== int2h
1172 && ! (int1l
== 0 && int1h
== 0))
1177 overflow
= div_and_round_double (code
, uns
, int1l
, int1h
, int2l
, int2h
,
1178 &low
, &hi
, &garbagel
, &garbageh
);
1181 case TRUNC_MOD_EXPR
:
1182 case FLOOR_MOD_EXPR
: case CEIL_MOD_EXPR
:
1183 /* This is a shortcut for a common special case. */
1184 if (int2h
== 0 && (HOST_WIDE_INT
) int2l
> 0
1185 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1186 && ! TREE_CONSTANT_OVERFLOW (arg2
)
1187 && int1h
== 0 && (HOST_WIDE_INT
) int1l
>= 0)
1189 if (code
== CEIL_MOD_EXPR
)
1191 low
= int1l
% int2l
, hi
= 0;
1195 /* ... fall through ... */
1197 case ROUND_MOD_EXPR
:
1198 overflow
= div_and_round_double (code
, uns
,
1199 int1l
, int1h
, int2l
, int2h
,
1200 &garbagel
, &garbageh
, &low
, &hi
);
1206 low
= (((unsigned HOST_WIDE_INT
) int1h
1207 < (unsigned HOST_WIDE_INT
) int2h
)
1208 || (((unsigned HOST_WIDE_INT
) int1h
1209 == (unsigned HOST_WIDE_INT
) int2h
)
1212 low
= (int1h
< int2h
1213 || (int1h
== int2h
&& int1l
< int2l
));
1215 if (low
== (code
== MIN_EXPR
))
1216 low
= int1l
, hi
= int1h
;
1218 low
= int2l
, hi
= int2h
;
1225 /* If this is for a sizetype, can be represented as one (signed)
1226 HOST_WIDE_INT word, and doesn't overflow, use size_int since it caches
1229 && ((hi
== 0 && (HOST_WIDE_INT
) low
>= 0)
1230 || (hi
== -1 && (HOST_WIDE_INT
) low
< 0))
1231 && overflow
== 0 && ! TREE_OVERFLOW (arg1
) && ! TREE_OVERFLOW (arg2
))
1232 return size_int_type_wide (low
, type
);
1235 t
= build_int_2 (low
, hi
);
1236 TREE_TYPE (t
) = TREE_TYPE (arg1
);
1241 ? (!uns
|| is_sizetype
) && overflow
1242 : (force_fit_type (t
, (!uns
|| is_sizetype
) && overflow
)
1244 | TREE_OVERFLOW (arg1
)
1245 | TREE_OVERFLOW (arg2
));
1247 /* If we're doing a size calculation, unsigned arithmetic does overflow.
1248 So check if force_fit_type truncated the value. */
1250 && ! TREE_OVERFLOW (t
)
1251 && (TREE_INT_CST_HIGH (t
) != hi
1252 || TREE_INT_CST_LOW (t
) != low
))
1253 TREE_OVERFLOW (t
) = 1;
1255 TREE_CONSTANT_OVERFLOW (t
) = (TREE_OVERFLOW (t
)
1256 | TREE_CONSTANT_OVERFLOW (arg1
)
1257 | TREE_CONSTANT_OVERFLOW (arg2
));
1261 /* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1262 constant. We assume ARG1 and ARG2 have the same data type, or at least
1263 are the same kind of constant and the same machine mode.
1265 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1268 const_binop (code
, arg1
, arg2
, notrunc
)
1269 enum tree_code code
;
1276 if (TREE_CODE (arg1
) == INTEGER_CST
)
1277 return int_const_binop (code
, arg1
, arg2
, notrunc
);
1279 if (TREE_CODE (arg1
) == REAL_CST
)
1283 REAL_VALUE_TYPE value
;
1286 d1
= TREE_REAL_CST (arg1
);
1287 d2
= TREE_REAL_CST (arg2
);
1289 /* If either operand is a NaN, just return it. Otherwise, set up
1290 for floating-point trap; we return an overflow. */
1291 if (REAL_VALUE_ISNAN (d1
))
1293 else if (REAL_VALUE_ISNAN (d2
))
1296 REAL_ARITHMETIC (value
, code
, d1
, d2
);
1298 t
= build_real (TREE_TYPE (arg1
),
1299 real_value_truncate (TYPE_MODE (TREE_TYPE (arg1
)),
1303 = (force_fit_type (t
, 0)
1304 | TREE_OVERFLOW (arg1
) | TREE_OVERFLOW (arg2
));
1305 TREE_CONSTANT_OVERFLOW (t
)
1307 | TREE_CONSTANT_OVERFLOW (arg1
)
1308 | TREE_CONSTANT_OVERFLOW (arg2
);
1311 if (TREE_CODE (arg1
) == COMPLEX_CST
)
1313 tree type
= TREE_TYPE (arg1
);
1314 tree r1
= TREE_REALPART (arg1
);
1315 tree i1
= TREE_IMAGPART (arg1
);
1316 tree r2
= TREE_REALPART (arg2
);
1317 tree i2
= TREE_IMAGPART (arg2
);
1323 t
= build_complex (type
,
1324 const_binop (PLUS_EXPR
, r1
, r2
, notrunc
),
1325 const_binop (PLUS_EXPR
, i1
, i2
, notrunc
));
1329 t
= build_complex (type
,
1330 const_binop (MINUS_EXPR
, r1
, r2
, notrunc
),
1331 const_binop (MINUS_EXPR
, i1
, i2
, notrunc
));
1335 t
= build_complex (type
,
1336 const_binop (MINUS_EXPR
,
1337 const_binop (MULT_EXPR
,
1339 const_binop (MULT_EXPR
,
1342 const_binop (PLUS_EXPR
,
1343 const_binop (MULT_EXPR
,
1345 const_binop (MULT_EXPR
,
1353 = const_binop (PLUS_EXPR
,
1354 const_binop (MULT_EXPR
, r2
, r2
, notrunc
),
1355 const_binop (MULT_EXPR
, i2
, i2
, notrunc
),
1358 t
= build_complex (type
,
1360 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1361 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1362 const_binop (PLUS_EXPR
,
1363 const_binop (MULT_EXPR
, r1
, r2
,
1365 const_binop (MULT_EXPR
, i1
, i2
,
1368 magsquared
, notrunc
),
1370 (INTEGRAL_TYPE_P (TREE_TYPE (r1
))
1371 ? TRUNC_DIV_EXPR
: RDIV_EXPR
,
1372 const_binop (MINUS_EXPR
,
1373 const_binop (MULT_EXPR
, i1
, r2
,
1375 const_binop (MULT_EXPR
, r1
, i2
,
1378 magsquared
, notrunc
));
1390 /* These are the hash table functions for the hash table of INTEGER_CST
1391 nodes of a sizetype. */
1393 /* Return the hash code code X, an INTEGER_CST. */
1401 return (TREE_INT_CST_HIGH (t
) ^ TREE_INT_CST_LOW (t
)
1402 ^ htab_hash_pointer (TREE_TYPE (t
))
1403 ^ (TREE_OVERFLOW (t
) << 20));
1406 /* Return nonzero if the value represented by *X (an INTEGER_CST tree node)
1407 is the same as that given by *Y, which is the same. */
1417 return (TREE_INT_CST_HIGH (xt
) == TREE_INT_CST_HIGH (yt
)
1418 && TREE_INT_CST_LOW (xt
) == TREE_INT_CST_LOW (yt
)
1419 && TREE_TYPE (xt
) == TREE_TYPE (yt
)
1420 && TREE_OVERFLOW (xt
) == TREE_OVERFLOW (yt
));
1423 /* Return an INTEGER_CST with value whose low-order HOST_BITS_PER_WIDE_INT
1424 bits are given by NUMBER and of the sizetype represented by KIND. */
1427 size_int_wide (number
, kind
)
1428 HOST_WIDE_INT number
;
1429 enum size_type_kind kind
;
1431 return size_int_type_wide (number
, sizetype_tab
[(int) kind
]);
1434 /* Likewise, but the desired type is specified explicitly. */
1436 static GTY (()) tree new_const
;
1437 static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node
)))
1441 size_int_type_wide (number
, type
)
1442 HOST_WIDE_INT number
;
1449 size_htab
= htab_create_ggc (1024, size_htab_hash
, size_htab_eq
, NULL
);
1450 new_const
= make_node (INTEGER_CST
);
1453 /* Adjust NEW_CONST to be the constant we want. If it's already in the
1454 hash table, we return the value from the hash table. Otherwise, we
1455 place that in the hash table and make a new node for the next time. */
1456 TREE_INT_CST_LOW (new_const
) = number
;
1457 TREE_INT_CST_HIGH (new_const
) = number
< 0 ? -1 : 0;
1458 TREE_TYPE (new_const
) = type
;
1459 TREE_OVERFLOW (new_const
) = TREE_CONSTANT_OVERFLOW (new_const
)
1460 = force_fit_type (new_const
, 0);
1462 slot
= htab_find_slot (size_htab
, new_const
, INSERT
);
1467 *slot
= (PTR
) new_const
;
1468 new_const
= make_node (INTEGER_CST
);
1472 return (tree
) *slot
;
1475 /* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1476 is a tree code. The type of the result is taken from the operands.
1477 Both must be the same type integer type and it must be a size type.
1478 If the operands are constant, so is the result. */
1481 size_binop (code
, arg0
, arg1
)
1482 enum tree_code code
;
1485 tree type
= TREE_TYPE (arg0
);
1487 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1488 || type
!= TREE_TYPE (arg1
))
1491 /* Handle the special case of two integer constants faster. */
1492 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
1494 /* And some specific cases even faster than that. */
1495 if (code
== PLUS_EXPR
&& integer_zerop (arg0
))
1497 else if ((code
== MINUS_EXPR
|| code
== PLUS_EXPR
)
1498 && integer_zerop (arg1
))
1500 else if (code
== MULT_EXPR
&& integer_onep (arg0
))
1503 /* Handle general case of two integer constants. */
1504 return int_const_binop (code
, arg0
, arg1
, 0);
1507 if (arg0
== error_mark_node
|| arg1
== error_mark_node
)
1508 return error_mark_node
;
1510 return fold (build (code
, type
, arg0
, arg1
));
1513 /* Given two values, either both of sizetype or both of bitsizetype,
1514 compute the difference between the two values. Return the value
1515 in signed type corresponding to the type of the operands. */
1518 size_diffop (arg0
, arg1
)
1521 tree type
= TREE_TYPE (arg0
);
1524 if (TREE_CODE (type
) != INTEGER_TYPE
|| ! TYPE_IS_SIZETYPE (type
)
1525 || type
!= TREE_TYPE (arg1
))
1528 /* If the type is already signed, just do the simple thing. */
1529 if (! TREE_UNSIGNED (type
))
1530 return size_binop (MINUS_EXPR
, arg0
, arg1
);
1532 ctype
= (type
== bitsizetype
|| type
== ubitsizetype
1533 ? sbitsizetype
: ssizetype
);
1535 /* If either operand is not a constant, do the conversions to the signed
1536 type and subtract. The hardware will do the right thing with any
1537 overflow in the subtraction. */
1538 if (TREE_CODE (arg0
) != INTEGER_CST
|| TREE_CODE (arg1
) != INTEGER_CST
)
1539 return size_binop (MINUS_EXPR
, convert (ctype
, arg0
),
1540 convert (ctype
, arg1
));
1542 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1543 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1544 overflow) and negate (which can't either). Special-case a result
1545 of zero while we're here. */
1546 if (tree_int_cst_equal (arg0
, arg1
))
1547 return convert (ctype
, integer_zero_node
);
1548 else if (tree_int_cst_lt (arg1
, arg0
))
1549 return convert (ctype
, size_binop (MINUS_EXPR
, arg0
, arg1
));
1551 return size_binop (MINUS_EXPR
, convert (ctype
, integer_zero_node
),
1552 convert (ctype
, size_binop (MINUS_EXPR
, arg1
, arg0
)));
1556 /* Given T, a tree representing type conversion of ARG1, a constant,
1557 return a constant tree representing the result of conversion. */
1560 fold_convert (t
, arg1
)
1564 tree type
= TREE_TYPE (t
);
1567 if (POINTER_TYPE_P (type
) || INTEGRAL_TYPE_P (type
))
1569 if (TREE_CODE (arg1
) == INTEGER_CST
)
1571 /* If we would build a constant wider than GCC supports,
1572 leave the conversion unfolded. */
1573 if (TYPE_PRECISION (type
) > 2 * HOST_BITS_PER_WIDE_INT
)
1576 /* If we are trying to make a sizetype for a small integer, use
1577 size_int to pick up cached types to reduce duplicate nodes. */
1578 if (TREE_CODE (type
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (type
)
1579 && !TREE_CONSTANT_OVERFLOW (arg1
)
1580 && compare_tree_int (arg1
, 10000) < 0)
1581 return size_int_type_wide (TREE_INT_CST_LOW (arg1
), type
);
1583 /* Given an integer constant, make new constant with new type,
1584 appropriately sign-extended or truncated. */
1585 t
= build_int_2 (TREE_INT_CST_LOW (arg1
),
1586 TREE_INT_CST_HIGH (arg1
));
1587 TREE_TYPE (t
) = type
;
1588 /* Indicate an overflow if (1) ARG1 already overflowed,
1589 or (2) force_fit_type indicates an overflow.
1590 Tell force_fit_type that an overflow has already occurred
1591 if ARG1 is a too-large unsigned value and T is signed.
1592 But don't indicate an overflow if converting a pointer. */
1594 = ((force_fit_type (t
,
1595 (TREE_INT_CST_HIGH (arg1
) < 0
1596 && (TREE_UNSIGNED (type
)
1597 < TREE_UNSIGNED (TREE_TYPE (arg1
)))))
1598 && ! POINTER_TYPE_P (TREE_TYPE (arg1
)))
1599 || TREE_OVERFLOW (arg1
));
1600 TREE_CONSTANT_OVERFLOW (t
)
1601 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1603 else if (TREE_CODE (arg1
) == REAL_CST
)
1605 /* Don't initialize these, use assignments.
1606 Initialized local aggregates don't work on old compilers. */
1610 tree type1
= TREE_TYPE (arg1
);
1613 x
= TREE_REAL_CST (arg1
);
1614 l
= real_value_from_int_cst (type1
, TYPE_MIN_VALUE (type
));
1616 no_upper_bound
= (TYPE_MAX_VALUE (type
) == NULL
);
1617 if (!no_upper_bound
)
1618 u
= real_value_from_int_cst (type1
, TYPE_MAX_VALUE (type
));
1620 /* See if X will be in range after truncation towards 0.
1621 To compensate for truncation, move the bounds away from 0,
1622 but reject if X exactly equals the adjusted bounds. */
1623 REAL_ARITHMETIC (l
, MINUS_EXPR
, l
, dconst1
);
1624 if (!no_upper_bound
)
1625 REAL_ARITHMETIC (u
, PLUS_EXPR
, u
, dconst1
);
1626 /* If X is a NaN, use zero instead and show we have an overflow.
1627 Otherwise, range check. */
1628 if (REAL_VALUE_ISNAN (x
))
1629 overflow
= 1, x
= dconst0
;
1630 else if (! (REAL_VALUES_LESS (l
, x
)
1632 && REAL_VALUES_LESS (x
, u
)))
1636 HOST_WIDE_INT low
, high
;
1637 REAL_VALUE_TO_INT (&low
, &high
, x
);
1638 t
= build_int_2 (low
, high
);
1640 TREE_TYPE (t
) = type
;
1642 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, overflow
);
1643 TREE_CONSTANT_OVERFLOW (t
)
1644 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1646 TREE_TYPE (t
) = type
;
1648 else if (TREE_CODE (type
) == REAL_TYPE
)
1650 if (TREE_CODE (arg1
) == INTEGER_CST
)
1651 return build_real_from_int_cst (type
, arg1
);
1652 if (TREE_CODE (arg1
) == REAL_CST
)
1654 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
1656 /* We make a copy of ARG1 so that we don't modify an
1657 existing constant tree. */
1658 t
= copy_node (arg1
);
1659 TREE_TYPE (t
) = type
;
1663 t
= build_real (type
,
1664 real_value_truncate (TYPE_MODE (type
),
1665 TREE_REAL_CST (arg1
)));
1668 = TREE_OVERFLOW (arg1
) | force_fit_type (t
, 0);
1669 TREE_CONSTANT_OVERFLOW (t
)
1670 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg1
);
1674 TREE_CONSTANT (t
) = 1;
1678 /* Return an expr equal to X but certainly not valid as an lvalue. */
1686 /* These things are certainly not lvalues. */
1687 if (TREE_CODE (x
) == NON_LVALUE_EXPR
1688 || TREE_CODE (x
) == INTEGER_CST
1689 || TREE_CODE (x
) == REAL_CST
1690 || TREE_CODE (x
) == STRING_CST
1691 || TREE_CODE (x
) == ADDR_EXPR
)
1694 result
= build1 (NON_LVALUE_EXPR
, TREE_TYPE (x
), x
);
1695 TREE_CONSTANT (result
) = TREE_CONSTANT (x
);
1699 /* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
1700 Zero means allow extended lvalues. */
1702 int pedantic_lvalues
;
1704 /* When pedantic, return an expr equal to X but certainly not valid as a
1705 pedantic lvalue. Otherwise, return X. */
1708 pedantic_non_lvalue (x
)
1711 if (pedantic_lvalues
)
1712 return non_lvalue (x
);
1717 /* Given a tree comparison code, return the code that is the logical inverse
1718 of the given code. It is not safe to do this for floating-point
1719 comparisons, except for NE_EXPR and EQ_EXPR. */
1721 static enum tree_code
1722 invert_tree_comparison (code
)
1723 enum tree_code code
;
1744 /* Similar, but return the comparison that results if the operands are
1745 swapped. This is safe for floating-point. */
1747 static enum tree_code
1748 swap_tree_comparison (code
)
1749 enum tree_code code
;
1770 /* Convert a comparison tree code from an enum tree_code representation
1771 into a compcode bit-based encoding. This function is the inverse of
1772 compcode_to_comparison. */
1775 comparison_to_compcode (code
)
1776 enum tree_code code
;
1797 /* Convert a compcode bit-based encoding of a comparison operator back
1798 to GCC's enum tree_code representation. This function is the
1799 inverse of comparison_to_compcode. */
1801 static enum tree_code
1802 compcode_to_comparison (code
)
1824 /* Return nonzero if CODE is a tree code that represents a truth value. */
1827 truth_value_p (code
)
1828 enum tree_code code
;
1830 return (TREE_CODE_CLASS (code
) == '<'
1831 || code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
1832 || code
== TRUTH_OR_EXPR
|| code
== TRUTH_ORIF_EXPR
1833 || code
== TRUTH_XOR_EXPR
|| code
== TRUTH_NOT_EXPR
);
1836 /* Return nonzero if two operands are necessarily equal.
1837 If ONLY_CONST is nonzero, only return nonzero for constants.
1838 This function tests whether the operands are indistinguishable;
1839 it does not test whether they are equal using C's == operation.
1840 The distinction is important for IEEE floating point, because
1841 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
1842 (2) two NaNs may be indistinguishable, but NaN!=NaN. */
1845 operand_equal_p (arg0
, arg1
, only_const
)
1849 /* If both types don't have the same signedness, then we can't consider
1850 them equal. We must check this before the STRIP_NOPS calls
1851 because they may change the signedness of the arguments. */
1852 if (TREE_UNSIGNED (TREE_TYPE (arg0
)) != TREE_UNSIGNED (TREE_TYPE (arg1
)))
1858 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
1859 /* This is needed for conversions and for COMPONENT_REF.
1860 Might as well play it safe and always test this. */
1861 || TREE_CODE (TREE_TYPE (arg0
)) == ERROR_MARK
1862 || TREE_CODE (TREE_TYPE (arg1
)) == ERROR_MARK
1863 || TYPE_MODE (TREE_TYPE (arg0
)) != TYPE_MODE (TREE_TYPE (arg1
)))
1866 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
1867 We don't care about side effects in that case because the SAVE_EXPR
1868 takes care of that for us. In all other cases, two expressions are
1869 equal if they have no side effects. If we have two identical
1870 expressions with side effects that should be treated the same due
1871 to the only side effects being identical SAVE_EXPR's, that will
1872 be detected in the recursive calls below. */
1873 if (arg0
== arg1
&& ! only_const
1874 && (TREE_CODE (arg0
) == SAVE_EXPR
1875 || (! TREE_SIDE_EFFECTS (arg0
) && ! TREE_SIDE_EFFECTS (arg1
))))
1878 /* Next handle constant cases, those for which we can return 1 even
1879 if ONLY_CONST is set. */
1880 if (TREE_CONSTANT (arg0
) && TREE_CONSTANT (arg1
))
1881 switch (TREE_CODE (arg0
))
1884 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1885 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1886 && tree_int_cst_equal (arg0
, arg1
));
1889 return (! TREE_CONSTANT_OVERFLOW (arg0
)
1890 && ! TREE_CONSTANT_OVERFLOW (arg1
)
1891 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0
),
1892 TREE_REAL_CST (arg1
)));
1898 if (TREE_CONSTANT_OVERFLOW (arg0
)
1899 || TREE_CONSTANT_OVERFLOW (arg1
))
1902 v1
= TREE_VECTOR_CST_ELTS (arg0
);
1903 v2
= TREE_VECTOR_CST_ELTS (arg1
);
1906 if (!operand_equal_p (v1
, v2
, only_const
))
1908 v1
= TREE_CHAIN (v1
);
1909 v2
= TREE_CHAIN (v2
);
1916 return (operand_equal_p (TREE_REALPART (arg0
), TREE_REALPART (arg1
),
1918 && operand_equal_p (TREE_IMAGPART (arg0
), TREE_IMAGPART (arg1
),
1922 return (TREE_STRING_LENGTH (arg0
) == TREE_STRING_LENGTH (arg1
)
1923 && ! memcmp (TREE_STRING_POINTER (arg0
),
1924 TREE_STRING_POINTER (arg1
),
1925 TREE_STRING_LENGTH (arg0
)));
1928 return operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0),
1937 switch (TREE_CODE_CLASS (TREE_CODE (arg0
)))
1940 /* Two conversions are equal only if signedness and modes match. */
1941 if ((TREE_CODE (arg0
) == NOP_EXPR
|| TREE_CODE (arg0
) == CONVERT_EXPR
)
1942 && (TREE_UNSIGNED (TREE_TYPE (arg0
))
1943 != TREE_UNSIGNED (TREE_TYPE (arg1
))))
1946 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1947 TREE_OPERAND (arg1
, 0), 0);
1951 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0)
1952 && operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1),
1956 /* For commutative ops, allow the other order. */
1957 return ((TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MULT_EXPR
1958 || TREE_CODE (arg0
) == MIN_EXPR
|| TREE_CODE (arg0
) == MAX_EXPR
1959 || TREE_CODE (arg0
) == BIT_IOR_EXPR
1960 || TREE_CODE (arg0
) == BIT_XOR_EXPR
1961 || TREE_CODE (arg0
) == BIT_AND_EXPR
1962 || TREE_CODE (arg0
) == NE_EXPR
|| TREE_CODE (arg0
) == EQ_EXPR
)
1963 && operand_equal_p (TREE_OPERAND (arg0
, 0),
1964 TREE_OPERAND (arg1
, 1), 0)
1965 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1966 TREE_OPERAND (arg1
, 0), 0));
1969 /* If either of the pointer (or reference) expressions we are dereferencing
1970 contain a side effect, these cannot be equal. */
1971 if (TREE_SIDE_EFFECTS (arg0
)
1972 || TREE_SIDE_EFFECTS (arg1
))
1975 switch (TREE_CODE (arg0
))
1978 return operand_equal_p (TREE_OPERAND (arg0
, 0),
1979 TREE_OPERAND (arg1
, 0), 0);
1983 case ARRAY_RANGE_REF
:
1984 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1985 TREE_OPERAND (arg1
, 0), 0)
1986 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1987 TREE_OPERAND (arg1
, 1), 0));
1990 return (operand_equal_p (TREE_OPERAND (arg0
, 0),
1991 TREE_OPERAND (arg1
, 0), 0)
1992 && operand_equal_p (TREE_OPERAND (arg0
, 1),
1993 TREE_OPERAND (arg1
, 1), 0)
1994 && operand_equal_p (TREE_OPERAND (arg0
, 2),
1995 TREE_OPERAND (arg1
, 2), 0));
2001 if (TREE_CODE (arg0
) == RTL_EXPR
)
2002 return rtx_equal_p (RTL_EXPR_RTL (arg0
), RTL_EXPR_RTL (arg1
));
2010 /* Similar to operand_equal_p, but see if ARG0 might have been made by
2011 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2013 When in doubt, return 0. */
2016 operand_equal_for_comparison_p (arg0
, arg1
, other
)
2020 int unsignedp1
, unsignedpo
;
2021 tree primarg0
, primarg1
, primother
;
2022 unsigned int correct_width
;
2024 if (operand_equal_p (arg0
, arg1
, 0))
2027 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0
))
2028 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
2031 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2032 and see if the inner values are the same. This removes any
2033 signedness comparison, which doesn't matter here. */
2034 primarg0
= arg0
, primarg1
= arg1
;
2035 STRIP_NOPS (primarg0
);
2036 STRIP_NOPS (primarg1
);
2037 if (operand_equal_p (primarg0
, primarg1
, 0))
2040 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2041 actual comparison operand, ARG0.
2043 First throw away any conversions to wider types
2044 already present in the operands. */
2046 primarg1
= get_narrower (arg1
, &unsignedp1
);
2047 primother
= get_narrower (other
, &unsignedpo
);
2049 correct_width
= TYPE_PRECISION (TREE_TYPE (arg1
));
2050 if (unsignedp1
== unsignedpo
2051 && TYPE_PRECISION (TREE_TYPE (primarg1
)) < correct_width
2052 && TYPE_PRECISION (TREE_TYPE (primother
)) < correct_width
)
2054 tree type
= TREE_TYPE (arg0
);
2056 /* Make sure shorter operand is extended the right way
2057 to match the longer operand. */
2058 primarg1
= convert ((*lang_hooks
.types
.signed_or_unsigned_type
)
2059 (unsignedp1
, TREE_TYPE (primarg1
)), primarg1
);
2061 if (operand_equal_p (arg0
, convert (type
, primarg1
), 0))
2068 /* See if ARG is an expression that is either a comparison or is performing
2069 arithmetic on comparisons. The comparisons must only be comparing
2070 two different values, which will be stored in *CVAL1 and *CVAL2; if
2071 they are nonzero it means that some operands have already been found.
2072 No variables may be used anywhere else in the expression except in the
2073 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2074 the expression and save_expr needs to be called with CVAL1 and CVAL2.
2076 If this is true, return 1. Otherwise, return zero. */
2079 twoval_comparison_p (arg
, cval1
, cval2
, save_p
)
2081 tree
*cval1
, *cval2
;
2084 enum tree_code code
= TREE_CODE (arg
);
2085 char class = TREE_CODE_CLASS (code
);
2087 /* We can handle some of the 'e' cases here. */
2088 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2090 else if (class == 'e'
2091 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
2092 || code
== COMPOUND_EXPR
))
2095 else if (class == 'e' && code
== SAVE_EXPR
&& SAVE_EXPR_RTL (arg
) == 0
2096 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg
, 0)))
2098 /* If we've already found a CVAL1 or CVAL2, this expression is
2099 two complex to handle. */
2100 if (*cval1
|| *cval2
)
2110 return twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
);
2113 return (twoval_comparison_p (TREE_OPERAND (arg
, 0), cval1
, cval2
, save_p
)
2114 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2115 cval1
, cval2
, save_p
));
2121 if (code
== COND_EXPR
)
2122 return (twoval_comparison_p (TREE_OPERAND (arg
, 0),
2123 cval1
, cval2
, save_p
)
2124 && twoval_comparison_p (TREE_OPERAND (arg
, 1),
2125 cval1
, cval2
, save_p
)
2126 && twoval_comparison_p (TREE_OPERAND (arg
, 2),
2127 cval1
, cval2
, save_p
));
2131 /* First see if we can handle the first operand, then the second. For
2132 the second operand, we know *CVAL1 can't be zero. It must be that
2133 one side of the comparison is each of the values; test for the
2134 case where this isn't true by failing if the two operands
2137 if (operand_equal_p (TREE_OPERAND (arg
, 0),
2138 TREE_OPERAND (arg
, 1), 0))
2142 *cval1
= TREE_OPERAND (arg
, 0);
2143 else if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 0), 0))
2145 else if (*cval2
== 0)
2146 *cval2
= TREE_OPERAND (arg
, 0);
2147 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 0), 0))
2152 if (operand_equal_p (*cval1
, TREE_OPERAND (arg
, 1), 0))
2154 else if (*cval2
== 0)
2155 *cval2
= TREE_OPERAND (arg
, 1);
2156 else if (operand_equal_p (*cval2
, TREE_OPERAND (arg
, 1), 0))
2168 /* ARG is a tree that is known to contain just arithmetic operations and
2169 comparisons. Evaluate the operations in the tree substituting NEW0 for
2170 any occurrence of OLD0 as an operand of a comparison and likewise for
2174 eval_subst (arg
, old0
, new0
, old1
, new1
)
2176 tree old0
, new0
, old1
, new1
;
2178 tree type
= TREE_TYPE (arg
);
2179 enum tree_code code
= TREE_CODE (arg
);
2180 char class = TREE_CODE_CLASS (code
);
2182 /* We can handle some of the 'e' cases here. */
2183 if (class == 'e' && code
== TRUTH_NOT_EXPR
)
2185 else if (class == 'e'
2186 && (code
== TRUTH_ANDIF_EXPR
|| code
== TRUTH_ORIF_EXPR
))
2192 return fold (build1 (code
, type
,
2193 eval_subst (TREE_OPERAND (arg
, 0),
2194 old0
, new0
, old1
, new1
)));
2197 return fold (build (code
, type
,
2198 eval_subst (TREE_OPERAND (arg
, 0),
2199 old0
, new0
, old1
, new1
),
2200 eval_subst (TREE_OPERAND (arg
, 1),
2201 old0
, new0
, old1
, new1
)));
2207 return eval_subst (TREE_OPERAND (arg
, 0), old0
, new0
, old1
, new1
);
2210 return eval_subst (TREE_OPERAND (arg
, 1), old0
, new0
, old1
, new1
);
2213 return fold (build (code
, type
,
2214 eval_subst (TREE_OPERAND (arg
, 0),
2215 old0
, new0
, old1
, new1
),
2216 eval_subst (TREE_OPERAND (arg
, 1),
2217 old0
, new0
, old1
, new1
),
2218 eval_subst (TREE_OPERAND (arg
, 2),
2219 old0
, new0
, old1
, new1
)));
2223 /* fall through - ??? */
2227 tree arg0
= TREE_OPERAND (arg
, 0);
2228 tree arg1
= TREE_OPERAND (arg
, 1);
2230 /* We need to check both for exact equality and tree equality. The
2231 former will be true if the operand has a side-effect. In that
2232 case, we know the operand occurred exactly once. */
2234 if (arg0
== old0
|| operand_equal_p (arg0
, old0
, 0))
2236 else if (arg0
== old1
|| operand_equal_p (arg0
, old1
, 0))
2239 if (arg1
== old0
|| operand_equal_p (arg1
, old0
, 0))
2241 else if (arg1
== old1
|| operand_equal_p (arg1
, old1
, 0))
2244 return fold (build (code
, type
, arg0
, arg1
));
2252 /* Return a tree for the case when the result of an expression is RESULT
2253 converted to TYPE and OMITTED was previously an operand of the expression
2254 but is now not needed (e.g., we folded OMITTED * 0).
2256 If OMITTED has side effects, we must evaluate it. Otherwise, just do
2257 the conversion of RESULT to TYPE. */
2260 omit_one_operand (type
, result
, omitted
)
2261 tree type
, result
, omitted
;
2263 tree t
= convert (type
, result
);
2265 if (TREE_SIDE_EFFECTS (omitted
))
2266 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2268 return non_lvalue (t
);
2271 /* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
2274 pedantic_omit_one_operand (type
, result
, omitted
)
2275 tree type
, result
, omitted
;
2277 tree t
= convert (type
, result
);
2279 if (TREE_SIDE_EFFECTS (omitted
))
2280 return build (COMPOUND_EXPR
, type
, omitted
, t
);
2282 return pedantic_non_lvalue (t
);
2285 /* Return a simplified tree node for the truth-negation of ARG. This
2286 never alters ARG itself. We assume that ARG is an operation that
2287 returns a truth value (0 or 1). */
2290 invert_truthvalue (arg
)
2293 tree type
= TREE_TYPE (arg
);
2294 enum tree_code code
= TREE_CODE (arg
);
2296 if (code
== ERROR_MARK
)
2299 /* If this is a comparison, we can simply invert it, except for
2300 floating-point non-equality comparisons, in which case we just
2301 enclose a TRUTH_NOT_EXPR around what we have. */
2303 if (TREE_CODE_CLASS (code
) == '<')
2305 if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg
, 0)))
2306 && !flag_unsafe_math_optimizations
2309 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2311 return build (invert_tree_comparison (code
), type
,
2312 TREE_OPERAND (arg
, 0), TREE_OPERAND (arg
, 1));
2318 return convert (type
, build_int_2 (integer_zerop (arg
), 0));
2320 case TRUTH_AND_EXPR
:
2321 return build (TRUTH_OR_EXPR
, type
,
2322 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2323 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2326 return build (TRUTH_AND_EXPR
, type
,
2327 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2328 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2330 case TRUTH_XOR_EXPR
:
2331 /* Here we can invert either operand. We invert the first operand
2332 unless the second operand is a TRUTH_NOT_EXPR in which case our
2333 result is the XOR of the first operand with the inside of the
2334 negation of the second operand. */
2336 if (TREE_CODE (TREE_OPERAND (arg
, 1)) == TRUTH_NOT_EXPR
)
2337 return build (TRUTH_XOR_EXPR
, type
, TREE_OPERAND (arg
, 0),
2338 TREE_OPERAND (TREE_OPERAND (arg
, 1), 0));
2340 return build (TRUTH_XOR_EXPR
, type
,
2341 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2342 TREE_OPERAND (arg
, 1));
2344 case TRUTH_ANDIF_EXPR
:
2345 return build (TRUTH_ORIF_EXPR
, type
,
2346 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2347 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2349 case TRUTH_ORIF_EXPR
:
2350 return build (TRUTH_ANDIF_EXPR
, type
,
2351 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2352 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2354 case TRUTH_NOT_EXPR
:
2355 return TREE_OPERAND (arg
, 0);
2358 return build (COND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2359 invert_truthvalue (TREE_OPERAND (arg
, 1)),
2360 invert_truthvalue (TREE_OPERAND (arg
, 2)));
2363 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg
, 0),
2364 invert_truthvalue (TREE_OPERAND (arg
, 1)));
2366 case WITH_RECORD_EXPR
:
2367 return build (WITH_RECORD_EXPR
, type
,
2368 invert_truthvalue (TREE_OPERAND (arg
, 0)),
2369 TREE_OPERAND (arg
, 1));
2371 case NON_LVALUE_EXPR
:
2372 return invert_truthvalue (TREE_OPERAND (arg
, 0));
2377 return build1 (TREE_CODE (arg
), type
,
2378 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2381 if (!integer_onep (TREE_OPERAND (arg
, 1)))
2383 return build (EQ_EXPR
, type
, arg
, convert (type
, integer_zero_node
));
2386 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2388 case CLEANUP_POINT_EXPR
:
2389 return build1 (CLEANUP_POINT_EXPR
, type
,
2390 invert_truthvalue (TREE_OPERAND (arg
, 0)));
2395 if (TREE_CODE (TREE_TYPE (arg
)) != BOOLEAN_TYPE
)
2397 return build1 (TRUTH_NOT_EXPR
, type
, arg
);
2400 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
2401 operands are another bit-wise operation with a common input. If so,
2402 distribute the bit operations to save an operation and possibly two if
2403 constants are involved. For example, convert
2404 (A | B) & (A | C) into A | (B & C)
2405 Further simplification will occur if B and C are constants.
2407 If this optimization cannot be done, 0 will be returned. */
2410 distribute_bit_expr (code
, type
, arg0
, arg1
)
2411 enum tree_code code
;
2418 if (TREE_CODE (arg0
) != TREE_CODE (arg1
)
2419 || TREE_CODE (arg0
) == code
2420 || (TREE_CODE (arg0
) != BIT_AND_EXPR
2421 && TREE_CODE (arg0
) != BIT_IOR_EXPR
))
2424 if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 0), 0))
2426 common
= TREE_OPERAND (arg0
, 0);
2427 left
= TREE_OPERAND (arg0
, 1);
2428 right
= TREE_OPERAND (arg1
, 1);
2430 else if (operand_equal_p (TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg1
, 1), 0))
2432 common
= TREE_OPERAND (arg0
, 0);
2433 left
= TREE_OPERAND (arg0
, 1);
2434 right
= TREE_OPERAND (arg1
, 0);
2436 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 0), 0))
2438 common
= TREE_OPERAND (arg0
, 1);
2439 left
= TREE_OPERAND (arg0
, 0);
2440 right
= TREE_OPERAND (arg1
, 1);
2442 else if (operand_equal_p (TREE_OPERAND (arg0
, 1), TREE_OPERAND (arg1
, 1), 0))
2444 common
= TREE_OPERAND (arg0
, 1);
2445 left
= TREE_OPERAND (arg0
, 0);
2446 right
= TREE_OPERAND (arg1
, 0);
2451 return fold (build (TREE_CODE (arg0
), type
, common
,
2452 fold (build (code
, type
, left
, right
))));
2455 /* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
2456 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2459 make_bit_field_ref (inner
, type
, bitsize
, bitpos
, unsignedp
)
2462 int bitsize
, bitpos
;
2465 tree result
= build (BIT_FIELD_REF
, type
, inner
,
2466 size_int (bitsize
), bitsize_int (bitpos
));
2468 TREE_UNSIGNED (result
) = unsignedp
;
2473 /* Optimize a bit-field compare.
2475 There are two cases: First is a compare against a constant and the
2476 second is a comparison of two items where the fields are at the same
2477 bit position relative to the start of a chunk (byte, halfword, word)
2478 large enough to contain it. In these cases we can avoid the shift
2479 implicit in bitfield extractions.
2481 For constants, we emit a compare of the shifted constant with the
2482 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
2483 compared. For two fields at the same position, we do the ANDs with the
2484 similar mask and compare the result of the ANDs.
2486 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
2487 COMPARE_TYPE is the type of the comparison, and LHS and RHS
2488 are the left and right operands of the comparison, respectively.
2490 If the optimization described above can be done, we return the resulting
2491 tree. Otherwise we return zero. */
2494 optimize_bit_field_compare (code
, compare_type
, lhs
, rhs
)
2495 enum tree_code code
;
2499 HOST_WIDE_INT lbitpos
, lbitsize
, rbitpos
, rbitsize
, nbitpos
, nbitsize
;
2500 tree type
= TREE_TYPE (lhs
);
2501 tree signed_type
, unsigned_type
;
2502 int const_p
= TREE_CODE (rhs
) == INTEGER_CST
;
2503 enum machine_mode lmode
, rmode
, nmode
;
2504 int lunsignedp
, runsignedp
;
2505 int lvolatilep
= 0, rvolatilep
= 0;
2506 tree linner
, rinner
= NULL_TREE
;
2510 /* Get all the information about the extractions being done. If the bit size
2511 if the same as the size of the underlying object, we aren't doing an
2512 extraction at all and so can do nothing. We also don't want to
2513 do anything if the inner expression is a PLACEHOLDER_EXPR since we
2514 then will no longer be able to replace it. */
2515 linner
= get_inner_reference (lhs
, &lbitsize
, &lbitpos
, &offset
, &lmode
,
2516 &lunsignedp
, &lvolatilep
);
2517 if (linner
== lhs
|| lbitsize
== GET_MODE_BITSIZE (lmode
) || lbitsize
< 0
2518 || offset
!= 0 || TREE_CODE (linner
) == PLACEHOLDER_EXPR
)
2523 /* If this is not a constant, we can only do something if bit positions,
2524 sizes, and signedness are the same. */
2525 rinner
= get_inner_reference (rhs
, &rbitsize
, &rbitpos
, &offset
, &rmode
,
2526 &runsignedp
, &rvolatilep
);
2528 if (rinner
== rhs
|| lbitpos
!= rbitpos
|| lbitsize
!= rbitsize
2529 || lunsignedp
!= runsignedp
|| offset
!= 0
2530 || TREE_CODE (rinner
) == PLACEHOLDER_EXPR
)
2534 /* See if we can find a mode to refer to this field. We should be able to,
2535 but fail if we can't. */
2536 nmode
= get_best_mode (lbitsize
, lbitpos
,
2537 const_p
? TYPE_ALIGN (TREE_TYPE (linner
))
2538 : MIN (TYPE_ALIGN (TREE_TYPE (linner
)),
2539 TYPE_ALIGN (TREE_TYPE (rinner
))),
2540 word_mode
, lvolatilep
|| rvolatilep
);
2541 if (nmode
== VOIDmode
)
2544 /* Set signed and unsigned types of the precision of this mode for the
2546 signed_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 0);
2547 unsigned_type
= (*lang_hooks
.types
.type_for_mode
) (nmode
, 1);
2549 /* Compute the bit position and size for the new reference and our offset
2550 within it. If the new reference is the same size as the original, we
2551 won't optimize anything, so return zero. */
2552 nbitsize
= GET_MODE_BITSIZE (nmode
);
2553 nbitpos
= lbitpos
& ~ (nbitsize
- 1);
2555 if (nbitsize
== lbitsize
)
2558 if (BYTES_BIG_ENDIAN
)
2559 lbitpos
= nbitsize
- lbitsize
- lbitpos
;
2561 /* Make the mask to be used against the extracted field. */
2562 mask
= build_int_2 (~0, ~0);
2563 TREE_TYPE (mask
) = unsigned_type
;
2564 force_fit_type (mask
, 0);
2565 mask
= convert (unsigned_type
, mask
);
2566 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (nbitsize
- lbitsize
), 0);
2567 mask
= const_binop (RSHIFT_EXPR
, mask
,
2568 size_int (nbitsize
- lbitsize
- lbitpos
), 0);
2571 /* If not comparing with constant, just rework the comparison
2573 return build (code
, compare_type
,
2574 build (BIT_AND_EXPR
, unsigned_type
,
2575 make_bit_field_ref (linner
, unsigned_type
,
2576 nbitsize
, nbitpos
, 1),
2578 build (BIT_AND_EXPR
, unsigned_type
,
2579 make_bit_field_ref (rinner
, unsigned_type
,
2580 nbitsize
, nbitpos
, 1),
2583 /* Otherwise, we are handling the constant case. See if the constant is too
2584 big for the field. Warn and return a tree of for 0 (false) if so. We do
2585 this not only for its own sake, but to avoid having to test for this
2586 error case below. If we didn't, we might generate wrong code.
2588 For unsigned fields, the constant shifted right by the field length should
2589 be all zero. For signed fields, the high-order bits should agree with
2594 if (! integer_zerop (const_binop (RSHIFT_EXPR
,
2595 convert (unsigned_type
, rhs
),
2596 size_int (lbitsize
), 0)))
2598 warning ("comparison is always %d due to width of bit-field",
2600 return convert (compare_type
,
2602 ? integer_one_node
: integer_zero_node
));
2607 tree tem
= const_binop (RSHIFT_EXPR
, convert (signed_type
, rhs
),
2608 size_int (lbitsize
- 1), 0);
2609 if (! integer_zerop (tem
) && ! integer_all_onesp (tem
))
2611 warning ("comparison is always %d due to width of bit-field",
2613 return convert (compare_type
,
2615 ? integer_one_node
: integer_zero_node
));
2619 /* Single-bit compares should always be against zero. */
2620 if (lbitsize
== 1 && ! integer_zerop (rhs
))
2622 code
= code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
;
2623 rhs
= convert (type
, integer_zero_node
);
2626 /* Make a new bitfield reference, shift the constant over the
2627 appropriate number of bits and mask it with the computed mask
2628 (in case this was a signed field). If we changed it, make a new one. */
2629 lhs
= make_bit_field_ref (linner
, unsigned_type
, nbitsize
, nbitpos
, 1);
2632 TREE_SIDE_EFFECTS (lhs
) = 1;
2633 TREE_THIS_VOLATILE (lhs
) = 1;
2636 rhs
= fold (const_binop (BIT_AND_EXPR
,
2637 const_binop (LSHIFT_EXPR
,
2638 convert (unsigned_type
, rhs
),
2639 size_int (lbitpos
), 0),
2642 return build (code
, compare_type
,
2643 build (BIT_AND_EXPR
, unsigned_type
, lhs
, mask
),
2647 /* Subroutine for fold_truthop: decode a field reference.
2649 If EXP is a comparison reference, we return the innermost reference.
2651 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
2652 set to the starting bit number.
2654 If the innermost field can be completely contained in a mode-sized
2655 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
2657 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
2658 otherwise it is not changed.
2660 *PUNSIGNEDP is set to the signedness of the field.
2662 *PMASK is set to the mask used. This is either contained in a
2663 BIT_AND_EXPR or derived from the width of the field.
2665 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2667 Return 0 if this is not a component reference or is one that we can't
2668 do anything with. */
2671 decode_field_reference (exp
, pbitsize
, pbitpos
, pmode
, punsignedp
,
2672 pvolatilep
, pmask
, pand_mask
)
2674 HOST_WIDE_INT
*pbitsize
, *pbitpos
;
2675 enum machine_mode
*pmode
;
2676 int *punsignedp
, *pvolatilep
;
2681 tree mask
, inner
, offset
;
2683 unsigned int precision
;
2685 /* All the optimizations using this function assume integer fields.
2686 There are problems with FP fields since the type_for_size call
2687 below can fail for, e.g., XFmode. */
2688 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp
)))
2693 if (TREE_CODE (exp
) == BIT_AND_EXPR
)
2695 and_mask
= TREE_OPERAND (exp
, 1);
2696 exp
= TREE_OPERAND (exp
, 0);
2697 STRIP_NOPS (exp
); STRIP_NOPS (and_mask
);
2698 if (TREE_CODE (and_mask
) != INTEGER_CST
)
2702 inner
= get_inner_reference (exp
, pbitsize
, pbitpos
, &offset
, pmode
,
2703 punsignedp
, pvolatilep
);
2704 if ((inner
== exp
&& and_mask
== 0)
2705 || *pbitsize
< 0 || offset
!= 0
2706 || TREE_CODE (inner
) == PLACEHOLDER_EXPR
)
2709 /* Compute the mask to access the bitfield. */
2710 unsigned_type
= (*lang_hooks
.types
.type_for_size
) (*pbitsize
, 1);
2711 precision
= TYPE_PRECISION (unsigned_type
);
2713 mask
= build_int_2 (~0, ~0);
2714 TREE_TYPE (mask
) = unsigned_type
;
2715 force_fit_type (mask
, 0);
2716 mask
= const_binop (LSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2717 mask
= const_binop (RSHIFT_EXPR
, mask
, size_int (precision
- *pbitsize
), 0);
2719 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
2721 mask
= fold (build (BIT_AND_EXPR
, unsigned_type
,
2722 convert (unsigned_type
, and_mask
), mask
));
2725 *pand_mask
= and_mask
;
2729 /* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2733 all_ones_mask_p (mask
, size
)
2737 tree type
= TREE_TYPE (mask
);
2738 unsigned int precision
= TYPE_PRECISION (type
);
2741 tmask
= build_int_2 (~0, ~0);
2742 TREE_TYPE (tmask
) = (*lang_hooks
.types
.signed_type
) (type
);
2743 force_fit_type (tmask
, 0);
2745 tree_int_cst_equal (mask
,
2746 const_binop (RSHIFT_EXPR
,
2747 const_binop (LSHIFT_EXPR
, tmask
,
2748 size_int (precision
- size
),
2750 size_int (precision
- size
), 0));
2753 /* Subroutine for fold: determine if VAL is the INTEGER_CONST that
2754 represents the sign bit of EXP's type. If EXP represents a sign
2755 or zero extension, also test VAL against the unextended type.
2756 The return value is the (sub)expression whose sign bit is VAL,
2757 or NULL_TREE otherwise. */
2760 sign_bit_p (exp
, val
)
2764 unsigned HOST_WIDE_INT lo
;
2769 /* Tree EXP must have an integral type. */
2770 t
= TREE_TYPE (exp
);
2771 if (! INTEGRAL_TYPE_P (t
))
2774 /* Tree VAL must be an integer constant. */
2775 if (TREE_CODE (val
) != INTEGER_CST
2776 || TREE_CONSTANT_OVERFLOW (val
))
2779 width
= TYPE_PRECISION (t
);
2780 if (width
> HOST_BITS_PER_WIDE_INT
)
2782 hi
= (unsigned HOST_WIDE_INT
) 1 << (width
- HOST_BITS_PER_WIDE_INT
- 1);
2788 lo
= (unsigned HOST_WIDE_INT
) 1 << (width
- 1);
2791 if (TREE_INT_CST_HIGH (val
) == hi
&& TREE_INT_CST_LOW (val
) == lo
)
2794 /* Handle extension from a narrower type. */
2795 if (TREE_CODE (exp
) == NOP_EXPR
2796 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp
, 0))) < width
)
2797 return sign_bit_p (TREE_OPERAND (exp
, 0), val
);
2802 /* Subroutine for fold_truthop: determine if an operand is simple enough
2803 to be evaluated unconditionally. */
2806 simple_operand_p (exp
)
2809 /* Strip any conversions that don't change the machine mode. */
2810 while ((TREE_CODE (exp
) == NOP_EXPR
2811 || TREE_CODE (exp
) == CONVERT_EXPR
)
2812 && (TYPE_MODE (TREE_TYPE (exp
))
2813 == TYPE_MODE (TREE_TYPE (TREE_OPERAND (exp
, 0)))))
2814 exp
= TREE_OPERAND (exp
, 0);
2816 return (TREE_CODE_CLASS (TREE_CODE (exp
)) == 'c'
2818 && ! TREE_ADDRESSABLE (exp
)
2819 && ! TREE_THIS_VOLATILE (exp
)
2820 && ! DECL_NONLOCAL (exp
)
2821 /* Don't regard global variables as simple. They may be
2822 allocated in ways unknown to the compiler (shared memory,
2823 #pragma weak, etc). */
2824 && ! TREE_PUBLIC (exp
)
2825 && ! DECL_EXTERNAL (exp
)
2826 /* Loading a static variable is unduly expensive, but global
2827 registers aren't expensive. */
2828 && (! TREE_STATIC (exp
) || DECL_REGISTER (exp
))));
2831 /* The following functions are subroutines to fold_range_test and allow it to
2832 try to change a logical combination of comparisons into a range test.
2835 X == 2 || X == 3 || X == 4 || X == 5
2839 (unsigned) (X - 2) <= 3
2841 We describe each set of comparisons as being either inside or outside
2842 a range, using a variable named like IN_P, and then describe the
2843 range with a lower and upper bound. If one of the bounds is omitted,
2844 it represents either the highest or lowest value of the type.
2846 In the comments below, we represent a range by two numbers in brackets
2847 preceded by a "+" to designate being inside that range, or a "-" to
2848 designate being outside that range, so the condition can be inverted by
2849 flipping the prefix. An omitted bound is represented by a "-". For
2850 example, "- [-, 10]" means being outside the range starting at the lowest
2851 possible value and ending at 10, in other words, being greater than 10.
2852 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
2855 We set up things so that the missing bounds are handled in a consistent
2856 manner so neither a missing bound nor "true" and "false" need to be
2857 handled using a special case. */
2859 /* Return the result of applying CODE to ARG0 and ARG1, but handle the case
2860 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
2861 and UPPER1_P are nonzero if the respective argument is an upper bound
2862 and zero for a lower. TYPE, if nonzero, is the type of the result; it
2863 must be specified for a comparison. ARG1 will be converted to ARG0's
2864 type if both are specified. */
2867 range_binop (code
, type
, arg0
, upper0_p
, arg1
, upper1_p
)
2868 enum tree_code code
;
2871 int upper0_p
, upper1_p
;
2877 /* If neither arg represents infinity, do the normal operation.
2878 Else, if not a comparison, return infinity. Else handle the special
2879 comparison rules. Note that most of the cases below won't occur, but
2880 are handled for consistency. */
2882 if (arg0
!= 0 && arg1
!= 0)
2884 tem
= fold (build (code
, type
!= 0 ? type
: TREE_TYPE (arg0
),
2885 arg0
, convert (TREE_TYPE (arg0
), arg1
)));
2887 return TREE_CODE (tem
) == INTEGER_CST
? tem
: 0;
2890 if (TREE_CODE_CLASS (code
) != '<')
2893 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
2894 for neither. In real maths, we cannot assume open ended ranges are
2895 the same. But, this is computer arithmetic, where numbers are finite.
2896 We can therefore make the transformation of any unbounded range with
2897 the value Z, Z being greater than any representable number. This permits
2898 us to treat unbounded ranges as equal. */
2899 sgn0
= arg0
!= 0 ? 0 : (upper0_p
? 1 : -1);
2900 sgn1
= arg1
!= 0 ? 0 : (upper1_p
? 1 : -1);
2904 result
= sgn0
== sgn1
;
2907 result
= sgn0
!= sgn1
;
2910 result
= sgn0
< sgn1
;
2913 result
= sgn0
<= sgn1
;
2916 result
= sgn0
> sgn1
;
2919 result
= sgn0
>= sgn1
;
2925 return convert (type
, result
? integer_one_node
: integer_zero_node
);
2928 /* Given EXP, a logical expression, set the range it is testing into
2929 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
2930 actually being tested. *PLOW and *PHIGH will be made of the same type
2931 as the returned expression. If EXP is not a comparison, we will most
2932 likely not be returning a useful value and range. */
2935 make_range (exp
, pin_p
, plow
, phigh
)
2940 enum tree_code code
;
2941 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
, type
= NULL_TREE
;
2942 tree orig_type
= NULL_TREE
;
2944 tree low
, high
, n_low
, n_high
;
2946 /* Start with simply saying "EXP != 0" and then look at the code of EXP
2947 and see if we can refine the range. Some of the cases below may not
2948 happen, but it doesn't seem worth worrying about this. We "continue"
2949 the outer loop when we've changed something; otherwise we "break"
2950 the switch, which will "break" the while. */
2952 in_p
= 0, low
= high
= convert (TREE_TYPE (exp
), integer_zero_node
);
2956 code
= TREE_CODE (exp
);
2958 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code
)))
2960 arg0
= TREE_OPERAND (exp
, 0);
2961 if (TREE_CODE_CLASS (code
) == '<'
2962 || TREE_CODE_CLASS (code
) == '1'
2963 || TREE_CODE_CLASS (code
) == '2')
2964 type
= TREE_TYPE (arg0
);
2965 if (TREE_CODE_CLASS (code
) == '2'
2966 || TREE_CODE_CLASS (code
) == '<'
2967 || (TREE_CODE_CLASS (code
) == 'e'
2968 && TREE_CODE_LENGTH (code
) > 1))
2969 arg1
= TREE_OPERAND (exp
, 1);
2972 /* Set ORIG_TYPE as soon as TYPE is non-null so that we do not
2973 lose a cast by accident. */
2974 if (type
!= NULL_TREE
&& orig_type
== NULL_TREE
)
2979 case TRUTH_NOT_EXPR
:
2980 in_p
= ! in_p
, exp
= arg0
;
2983 case EQ_EXPR
: case NE_EXPR
:
2984 case LT_EXPR
: case LE_EXPR
: case GE_EXPR
: case GT_EXPR
:
2985 /* We can only do something if the range is testing for zero
2986 and if the second operand is an integer constant. Note that
2987 saying something is "in" the range we make is done by
2988 complementing IN_P since it will set in the initial case of
2989 being not equal to zero; "out" is leaving it alone. */
2990 if (low
== 0 || high
== 0
2991 || ! integer_zerop (low
) || ! integer_zerop (high
)
2992 || TREE_CODE (arg1
) != INTEGER_CST
)
2997 case NE_EXPR
: /* - [c, c] */
3000 case EQ_EXPR
: /* + [c, c] */
3001 in_p
= ! in_p
, low
= high
= arg1
;
3003 case GT_EXPR
: /* - [-, c] */
3004 low
= 0, high
= arg1
;
3006 case GE_EXPR
: /* + [c, -] */
3007 in_p
= ! in_p
, low
= arg1
, high
= 0;
3009 case LT_EXPR
: /* - [c, -] */
3010 low
= arg1
, high
= 0;
3012 case LE_EXPR
: /* + [-, c] */
3013 in_p
= ! in_p
, low
= 0, high
= arg1
;
3021 /* If this is an unsigned comparison, we also know that EXP is
3022 greater than or equal to zero. We base the range tests we make
3023 on that fact, so we record it here so we can parse existing
3025 if (TREE_UNSIGNED (type
) && (low
== 0 || high
== 0))
3027 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
, in_p
, low
, high
,
3028 1, convert (type
, integer_zero_node
),
3032 in_p
= n_in_p
, low
= n_low
, high
= n_high
;
3034 /* If the high bound is missing, but we
3035 have a low bound, reverse the range so
3036 it goes from zero to the low bound minus 1. */
3037 if (high
== 0 && low
)
3040 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low
, 0,
3041 integer_one_node
, 0);
3042 low
= convert (type
, integer_zero_node
);
3048 /* (-x) IN [a,b] -> x in [-b, -a] */
3049 n_low
= range_binop (MINUS_EXPR
, type
,
3050 convert (type
, integer_zero_node
), 0, high
, 1);
3051 n_high
= range_binop (MINUS_EXPR
, type
,
3052 convert (type
, integer_zero_node
), 0, low
, 0);
3053 low
= n_low
, high
= n_high
;
3059 exp
= build (MINUS_EXPR
, type
, negate_expr (arg0
),
3060 convert (type
, integer_one_node
));
3063 case PLUS_EXPR
: case MINUS_EXPR
:
3064 if (TREE_CODE (arg1
) != INTEGER_CST
)
3067 /* If EXP is signed, any overflow in the computation is undefined,
3068 so we don't worry about it so long as our computations on
3069 the bounds don't overflow. For unsigned, overflow is defined
3070 and this is exactly the right thing. */
3071 n_low
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3072 type
, low
, 0, arg1
, 0);
3073 n_high
= range_binop (code
== MINUS_EXPR
? PLUS_EXPR
: MINUS_EXPR
,
3074 type
, high
, 1, arg1
, 0);
3075 if ((n_low
!= 0 && TREE_OVERFLOW (n_low
))
3076 || (n_high
!= 0 && TREE_OVERFLOW (n_high
)))
3079 /* Check for an unsigned range which has wrapped around the maximum
3080 value thus making n_high < n_low, and normalize it. */
3081 if (n_low
&& n_high
&& tree_int_cst_lt (n_high
, n_low
))
3083 low
= range_binop (PLUS_EXPR
, type
, n_high
, 0,
3084 integer_one_node
, 0);
3085 high
= range_binop (MINUS_EXPR
, type
, n_low
, 0,
3086 integer_one_node
, 0);
3088 /* If the range is of the form +/- [ x+1, x ], we won't
3089 be able to normalize it. But then, it represents the
3090 whole range or the empty set, so make it
3092 if (tree_int_cst_equal (n_low
, low
)
3093 && tree_int_cst_equal (n_high
, high
))
3099 low
= n_low
, high
= n_high
;
3104 case NOP_EXPR
: case NON_LVALUE_EXPR
: case CONVERT_EXPR
:
3105 if (TYPE_PRECISION (type
) > TYPE_PRECISION (orig_type
))
3108 if (! INTEGRAL_TYPE_P (type
)
3109 || (low
!= 0 && ! int_fits_type_p (low
, type
))
3110 || (high
!= 0 && ! int_fits_type_p (high
, type
)))
3113 n_low
= low
, n_high
= high
;
3116 n_low
= convert (type
, n_low
);
3119 n_high
= convert (type
, n_high
);
3121 /* If we're converting from an unsigned to a signed type,
3122 we will be doing the comparison as unsigned. The tests above
3123 have already verified that LOW and HIGH are both positive.
3125 So we have to make sure that the original unsigned value will
3126 be interpreted as positive. */
3127 if (TREE_UNSIGNED (type
) && ! TREE_UNSIGNED (TREE_TYPE (exp
)))
3129 tree equiv_type
= (*lang_hooks
.types
.type_for_mode
)
3130 (TYPE_MODE (type
), 1);
3133 /* A range without an upper bound is, naturally, unbounded.
3134 Since convert would have cropped a very large value, use
3135 the max value for the destination type. */
3137 = TYPE_MAX_VALUE (equiv_type
) ? TYPE_MAX_VALUE (equiv_type
)
3138 : TYPE_MAX_VALUE (type
);
3140 if (TYPE_PRECISION (type
) == TYPE_PRECISION (TREE_TYPE (exp
)))
3141 high_positive
= fold (build (RSHIFT_EXPR
, type
,
3142 convert (type
, high_positive
),
3143 convert (type
, integer_one_node
)));
3145 /* If the low bound is specified, "and" the range with the
3146 range for which the original unsigned value will be
3150 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3152 1, convert (type
, integer_zero_node
),
3156 in_p
= (n_in_p
== in_p
);
3160 /* Otherwise, "or" the range with the range of the input
3161 that will be interpreted as negative. */
3162 if (! merge_ranges (&n_in_p
, &n_low
, &n_high
,
3164 1, convert (type
, integer_zero_node
),
3168 in_p
= (in_p
!= n_in_p
);
3173 low
= n_low
, high
= n_high
;
3183 /* If EXP is a constant, we can evaluate whether this is true or false. */
3184 if (TREE_CODE (exp
) == INTEGER_CST
)
3186 in_p
= in_p
== (integer_onep (range_binop (GE_EXPR
, integer_type_node
,
3188 && integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3194 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3198 /* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
3199 type, TYPE, return an expression to test if EXP is in (or out of, depending
3200 on IN_P) the range. */
3203 build_range_check (type
, exp
, in_p
, low
, high
)
3209 tree etype
= TREE_TYPE (exp
);
3213 && (0 != (value
= build_range_check (type
, exp
, 1, low
, high
))))
3214 return invert_truthvalue (value
);
3216 if (low
== 0 && high
== 0)
3217 return convert (type
, integer_one_node
);
3220 return fold (build (LE_EXPR
, type
, exp
, high
));
3223 return fold (build (GE_EXPR
, type
, exp
, low
));
3225 if (operand_equal_p (low
, high
, 0))
3226 return fold (build (EQ_EXPR
, type
, exp
, low
));
3228 if (integer_zerop (low
))
3230 if (! TREE_UNSIGNED (etype
))
3232 etype
= (*lang_hooks
.types
.unsigned_type
) (etype
);
3233 high
= convert (etype
, high
);
3234 exp
= convert (etype
, exp
);
3236 return build_range_check (type
, exp
, 1, 0, high
);
3239 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
3240 if (integer_onep (low
) && TREE_CODE (high
) == INTEGER_CST
)
3242 unsigned HOST_WIDE_INT lo
;
3246 prec
= TYPE_PRECISION (etype
);
3247 if (prec
<= HOST_BITS_PER_WIDE_INT
)
3250 lo
= ((unsigned HOST_WIDE_INT
) 1 << (prec
- 1)) - 1;
3254 hi
= ((HOST_WIDE_INT
) 1 << (prec
- HOST_BITS_PER_WIDE_INT
- 1)) - 1;
3255 lo
= (unsigned HOST_WIDE_INT
) -1;
3258 if (TREE_INT_CST_HIGH (high
) == hi
&& TREE_INT_CST_LOW (high
) == lo
)
3260 if (TREE_UNSIGNED (etype
))
3262 etype
= (*lang_hooks
.types
.signed_type
) (etype
);
3263 exp
= convert (etype
, exp
);
3265 return fold (build (GT_EXPR
, type
, exp
,
3266 convert (etype
, integer_zero_node
)));
3270 if (0 != (value
= const_binop (MINUS_EXPR
, high
, low
, 0))
3271 && ! TREE_OVERFLOW (value
))
3272 return build_range_check (type
,
3273 fold (build (MINUS_EXPR
, etype
, exp
, low
)),
3274 1, convert (etype
, integer_zero_node
), value
);
3279 /* Given two ranges, see if we can merge them into one. Return 1 if we
3280 can, 0 if we can't. Set the output range into the specified parameters. */
3283 merge_ranges (pin_p
, plow
, phigh
, in0_p
, low0
, high0
, in1_p
, low1
, high1
)
3287 tree low0
, high0
, low1
, high1
;
3295 int lowequal
= ((low0
== 0 && low1
== 0)
3296 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3297 low0
, 0, low1
, 0)));
3298 int highequal
= ((high0
== 0 && high1
== 0)
3299 || integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3300 high0
, 1, high1
, 1)));
3302 /* Make range 0 be the range that starts first, or ends last if they
3303 start at the same value. Swap them if it isn't. */
3304 if (integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3307 && integer_onep (range_binop (GT_EXPR
, integer_type_node
,
3308 high1
, 1, high0
, 1))))
3310 temp
= in0_p
, in0_p
= in1_p
, in1_p
= temp
;
3311 tem
= low0
, low0
= low1
, low1
= tem
;
3312 tem
= high0
, high0
= high1
, high1
= tem
;
3315 /* Now flag two cases, whether the ranges are disjoint or whether the
3316 second range is totally subsumed in the first. Note that the tests
3317 below are simplified by the ones above. */
3318 no_overlap
= integer_onep (range_binop (LT_EXPR
, integer_type_node
,
3319 high0
, 1, low1
, 0));
3320 subset
= integer_onep (range_binop (LE_EXPR
, integer_type_node
,
3321 high1
, 1, high0
, 1));
3323 /* We now have four cases, depending on whether we are including or
3324 excluding the two ranges. */
3327 /* If they don't overlap, the result is false. If the second range
3328 is a subset it is the result. Otherwise, the range is from the start
3329 of the second to the end of the first. */
3331 in_p
= 0, low
= high
= 0;
3333 in_p
= 1, low
= low1
, high
= high1
;
3335 in_p
= 1, low
= low1
, high
= high0
;
3338 else if (in0_p
&& ! in1_p
)
3340 /* If they don't overlap, the result is the first range. If they are
3341 equal, the result is false. If the second range is a subset of the
3342 first, and the ranges begin at the same place, we go from just after
3343 the end of the first range to the end of the second. If the second
3344 range is not a subset of the first, or if it is a subset and both
3345 ranges end at the same place, the range starts at the start of the
3346 first range and ends just before the second range.
3347 Otherwise, we can't describe this as a single range. */
3349 in_p
= 1, low
= low0
, high
= high0
;
3350 else if (lowequal
&& highequal
)
3351 in_p
= 0, low
= high
= 0;
3352 else if (subset
&& lowequal
)
3354 in_p
= 1, high
= high0
;
3355 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high1
, 0,
3356 integer_one_node
, 0);
3358 else if (! subset
|| highequal
)
3360 in_p
= 1, low
= low0
;
3361 high
= range_binop (MINUS_EXPR
, NULL_TREE
, low1
, 0,
3362 integer_one_node
, 0);
3368 else if (! in0_p
&& in1_p
)
3370 /* If they don't overlap, the result is the second range. If the second
3371 is a subset of the first, the result is false. Otherwise,
3372 the range starts just after the first range and ends at the
3373 end of the second. */
3375 in_p
= 1, low
= low1
, high
= high1
;
3376 else if (subset
|| highequal
)
3377 in_p
= 0, low
= high
= 0;
3380 in_p
= 1, high
= high1
;
3381 low
= range_binop (PLUS_EXPR
, NULL_TREE
, high0
, 1,
3382 integer_one_node
, 0);
3388 /* The case where we are excluding both ranges. Here the complex case
3389 is if they don't overlap. In that case, the only time we have a
3390 range is if they are adjacent. If the second is a subset of the
3391 first, the result is the first. Otherwise, the range to exclude
3392 starts at the beginning of the first range and ends at the end of the
3396 if (integer_onep (range_binop (EQ_EXPR
, integer_type_node
,
3397 range_binop (PLUS_EXPR
, NULL_TREE
,
3399 integer_one_node
, 1),
3401 in_p
= 0, low
= low0
, high
= high1
;
3406 in_p
= 0, low
= low0
, high
= high0
;
3408 in_p
= 0, low
= low0
, high
= high1
;
3411 *pin_p
= in_p
, *plow
= low
, *phigh
= high
;
3415 /* EXP is some logical combination of boolean tests. See if we can
3416 merge it into some range test. Return the new tree if so. */
3419 fold_range_test (exp
)
3422 int or_op
= (TREE_CODE (exp
) == TRUTH_ORIF_EXPR
3423 || TREE_CODE (exp
) == TRUTH_OR_EXPR
);
3424 int in0_p
, in1_p
, in_p
;
3425 tree low0
, low1
, low
, high0
, high1
, high
;
3426 tree lhs
= make_range (TREE_OPERAND (exp
, 0), &in0_p
, &low0
, &high0
);
3427 tree rhs
= make_range (TREE_OPERAND (exp
, 1), &in1_p
, &low1
, &high1
);
3430 /* If this is an OR operation, invert both sides; we will invert
3431 again at the end. */
3433 in0_p
= ! in0_p
, in1_p
= ! in1_p
;
3435 /* If both expressions are the same, if we can merge the ranges, and we
3436 can build the range test, return it or it inverted. If one of the
3437 ranges is always true or always false, consider it to be the same
3438 expression as the other. */
3439 if ((lhs
== 0 || rhs
== 0 || operand_equal_p (lhs
, rhs
, 0))
3440 && merge_ranges (&in_p
, &low
, &high
, in0_p
, low0
, high0
,
3442 && 0 != (tem
= (build_range_check (TREE_TYPE (exp
),
3444 : rhs
!= 0 ? rhs
: integer_zero_node
,
3446 return or_op
? invert_truthvalue (tem
) : tem
;
3448 /* On machines where the branch cost is expensive, if this is a
3449 short-circuited branch and the underlying object on both sides
3450 is the same, make a non-short-circuit operation. */
3451 else if (BRANCH_COST
>= 2
3452 && lhs
!= 0 && rhs
!= 0
3453 && (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3454 || TREE_CODE (exp
) == TRUTH_ORIF_EXPR
)
3455 && operand_equal_p (lhs
, rhs
, 0))
3457 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
3458 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
3459 which cases we can't do this. */
3460 if (simple_operand_p (lhs
))
3461 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3462 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3463 TREE_TYPE (exp
), TREE_OPERAND (exp
, 0),
3464 TREE_OPERAND (exp
, 1));
3466 else if ((*lang_hooks
.decls
.global_bindings_p
) () == 0
3467 && ! contains_placeholder_p (lhs
))
3469 tree common
= save_expr (lhs
);
3471 if (0 != (lhs
= build_range_check (TREE_TYPE (exp
), common
,
3472 or_op
? ! in0_p
: in0_p
,
3474 && (0 != (rhs
= build_range_check (TREE_TYPE (exp
), common
,
3475 or_op
? ! in1_p
: in1_p
,
3477 return build (TREE_CODE (exp
) == TRUTH_ANDIF_EXPR
3478 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
,
3479 TREE_TYPE (exp
), lhs
, rhs
);
3486 /* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
3487 bit value. Arrange things so the extra bits will be set to zero if and
3488 only if C is signed-extended to its full width. If MASK is nonzero,
3489 it is an INTEGER_CST that should be AND'ed with the extra bits. */
3492 unextend (c
, p
, unsignedp
, mask
)
3498 tree type
= TREE_TYPE (c
);
3499 int modesize
= GET_MODE_BITSIZE (TYPE_MODE (type
));
3502 if (p
== modesize
|| unsignedp
)
3505 /* We work by getting just the sign bit into the low-order bit, then
3506 into the high-order bit, then sign-extend. We then XOR that value
3508 temp
= const_binop (RSHIFT_EXPR
, c
, size_int (p
- 1), 0);
3509 temp
= const_binop (BIT_AND_EXPR
, temp
, size_int (1), 0);
3511 /* We must use a signed type in order to get an arithmetic right shift.
3512 However, we must also avoid introducing accidental overflows, so that
3513 a subsequent call to integer_zerop will work. Hence we must
3514 do the type conversion here. At this point, the constant is either
3515 zero or one, and the conversion to a signed type can never overflow.
3516 We could get an overflow if this conversion is done anywhere else. */
3517 if (TREE_UNSIGNED (type
))
3518 temp
= convert ((*lang_hooks
.types
.signed_type
) (type
), temp
);
3520 temp
= const_binop (LSHIFT_EXPR
, temp
, size_int (modesize
- 1), 0);
3521 temp
= const_binop (RSHIFT_EXPR
, temp
, size_int (modesize
- p
- 1), 0);
3523 temp
= const_binop (BIT_AND_EXPR
, temp
, convert (TREE_TYPE (c
), mask
), 0);
3524 /* If necessary, convert the type back to match the type of C. */
3525 if (TREE_UNSIGNED (type
))
3526 temp
= convert (type
, temp
);
3528 return convert (type
, const_binop (BIT_XOR_EXPR
, c
, temp
, 0));
3531 /* Find ways of folding logical expressions of LHS and RHS:
3532 Try to merge two comparisons to the same innermost item.
3533 Look for range tests like "ch >= '0' && ch <= '9'".
3534 Look for combinations of simple terms on machines with expensive branches
3535 and evaluate the RHS unconditionally.
3537 For example, if we have p->a == 2 && p->b == 4 and we can make an
3538 object large enough to span both A and B, we can do this with a comparison
3539 against the object ANDed with the a mask.
3541 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
3542 operations to do this with one comparison.
3544 We check for both normal comparisons and the BIT_AND_EXPRs made this by
3545 function and the one above.
3547 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
3548 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
3550 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
3553 We return the simplified tree or 0 if no optimization is possible. */
3556 fold_truthop (code
, truth_type
, lhs
, rhs
)
3557 enum tree_code code
;
3558 tree truth_type
, lhs
, rhs
;
3560 /* If this is the "or" of two comparisons, we can do something if
3561 the comparisons are NE_EXPR. If this is the "and", we can do something
3562 if the comparisons are EQ_EXPR. I.e.,
3563 (a->b == 2 && a->c == 4) can become (a->new == NEW).
3565 WANTED_CODE is this operation code. For single bit fields, we can
3566 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
3567 comparison for one-bit fields. */
3569 enum tree_code wanted_code
;
3570 enum tree_code lcode
, rcode
;
3571 tree ll_arg
, lr_arg
, rl_arg
, rr_arg
;
3572 tree ll_inner
, lr_inner
, rl_inner
, rr_inner
;
3573 HOST_WIDE_INT ll_bitsize
, ll_bitpos
, lr_bitsize
, lr_bitpos
;
3574 HOST_WIDE_INT rl_bitsize
, rl_bitpos
, rr_bitsize
, rr_bitpos
;
3575 HOST_WIDE_INT xll_bitpos
, xlr_bitpos
, xrl_bitpos
, xrr_bitpos
;
3576 HOST_WIDE_INT lnbitsize
, lnbitpos
, rnbitsize
, rnbitpos
;
3577 int ll_unsignedp
, lr_unsignedp
, rl_unsignedp
, rr_unsignedp
;
3578 enum machine_mode ll_mode
, lr_mode
, rl_mode
, rr_mode
;
3579 enum machine_mode lnmode
, rnmode
;
3580 tree ll_mask
, lr_mask
, rl_mask
, rr_mask
;
3581 tree ll_and_mask
, lr_and_mask
, rl_and_mask
, rr_and_mask
;
3582 tree l_const
, r_const
;
3583 tree lntype
, rntype
, result
;
3584 int first_bit
, end_bit
;
3587 /* Start by getting the comparison codes. Fail if anything is volatile.
3588 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
3589 it were surrounded with a NE_EXPR. */
3591 if (TREE_SIDE_EFFECTS (lhs
) || TREE_SIDE_EFFECTS (rhs
))
3594 lcode
= TREE_CODE (lhs
);
3595 rcode
= TREE_CODE (rhs
);
3597 if (lcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (lhs
, 1)))
3598 lcode
= NE_EXPR
, lhs
= build (NE_EXPR
, truth_type
, lhs
, integer_zero_node
);
3600 if (rcode
== BIT_AND_EXPR
&& integer_onep (TREE_OPERAND (rhs
, 1)))
3601 rcode
= NE_EXPR
, rhs
= build (NE_EXPR
, truth_type
, rhs
, integer_zero_node
);
3603 if (TREE_CODE_CLASS (lcode
) != '<' || TREE_CODE_CLASS (rcode
) != '<')
3606 code
= ((code
== TRUTH_AND_EXPR
|| code
== TRUTH_ANDIF_EXPR
)
3607 ? TRUTH_AND_EXPR
: TRUTH_OR_EXPR
);
3609 ll_arg
= TREE_OPERAND (lhs
, 0);
3610 lr_arg
= TREE_OPERAND (lhs
, 1);
3611 rl_arg
= TREE_OPERAND (rhs
, 0);
3612 rr_arg
= TREE_OPERAND (rhs
, 1);
3614 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
3615 if (simple_operand_p (ll_arg
)
3616 && simple_operand_p (lr_arg
)
3617 && !FLOAT_TYPE_P (TREE_TYPE (ll_arg
)))
3621 if (operand_equal_p (ll_arg
, rl_arg
, 0)
3622 && operand_equal_p (lr_arg
, rr_arg
, 0))
3624 int lcompcode
, rcompcode
;
3626 lcompcode
= comparison_to_compcode (lcode
);
3627 rcompcode
= comparison_to_compcode (rcode
);
3628 compcode
= (code
== TRUTH_AND_EXPR
)
3629 ? lcompcode
& rcompcode
3630 : lcompcode
| rcompcode
;
3632 else if (operand_equal_p (ll_arg
, rr_arg
, 0)
3633 && operand_equal_p (lr_arg
, rl_arg
, 0))
3635 int lcompcode
, rcompcode
;
3637 rcode
= swap_tree_comparison (rcode
);
3638 lcompcode
= comparison_to_compcode (lcode
);
3639 rcompcode
= comparison_to_compcode (rcode
);
3640 compcode
= (code
== TRUTH_AND_EXPR
)
3641 ? lcompcode
& rcompcode
3642 : lcompcode
| rcompcode
;
3647 if (compcode
== COMPCODE_TRUE
)
3648 return convert (truth_type
, integer_one_node
);
3649 else if (compcode
== COMPCODE_FALSE
)
3650 return convert (truth_type
, integer_zero_node
);
3651 else if (compcode
!= -1)
3652 return build (compcode_to_comparison (compcode
),
3653 truth_type
, ll_arg
, lr_arg
);
3656 /* If the RHS can be evaluated unconditionally and its operands are
3657 simple, it wins to evaluate the RHS unconditionally on machines
3658 with expensive branches. In this case, this isn't a comparison
3659 that can be merged. Avoid doing this if the RHS is a floating-point
3660 comparison since those can trap. */
3662 if (BRANCH_COST
>= 2
3663 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg
))
3664 && simple_operand_p (rl_arg
)
3665 && simple_operand_p (rr_arg
))
3667 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
3668 if (code
== TRUTH_OR_EXPR
3669 && lcode
== NE_EXPR
&& integer_zerop (lr_arg
)
3670 && rcode
== NE_EXPR
&& integer_zerop (rr_arg
)
3671 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3672 return build (NE_EXPR
, truth_type
,
3673 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3677 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
3678 if (code
== TRUTH_AND_EXPR
3679 && lcode
== EQ_EXPR
&& integer_zerop (lr_arg
)
3680 && rcode
== EQ_EXPR
&& integer_zerop (rr_arg
)
3681 && TREE_TYPE (ll_arg
) == TREE_TYPE (rl_arg
))
3682 return build (EQ_EXPR
, truth_type
,
3683 build (BIT_IOR_EXPR
, TREE_TYPE (ll_arg
),
3687 return build (code
, truth_type
, lhs
, rhs
);
3690 /* See if the comparisons can be merged. Then get all the parameters for
3693 if ((lcode
!= EQ_EXPR
&& lcode
!= NE_EXPR
)
3694 || (rcode
!= EQ_EXPR
&& rcode
!= NE_EXPR
))
3698 ll_inner
= decode_field_reference (ll_arg
,
3699 &ll_bitsize
, &ll_bitpos
, &ll_mode
,
3700 &ll_unsignedp
, &volatilep
, &ll_mask
,
3702 lr_inner
= decode_field_reference (lr_arg
,
3703 &lr_bitsize
, &lr_bitpos
, &lr_mode
,
3704 &lr_unsignedp
, &volatilep
, &lr_mask
,
3706 rl_inner
= decode_field_reference (rl_arg
,
3707 &rl_bitsize
, &rl_bitpos
, &rl_mode
,
3708 &rl_unsignedp
, &volatilep
, &rl_mask
,
3710 rr_inner
= decode_field_reference (rr_arg
,
3711 &rr_bitsize
, &rr_bitpos
, &rr_mode
,
3712 &rr_unsignedp
, &volatilep
, &rr_mask
,
3715 /* It must be true that the inner operation on the lhs of each
3716 comparison must be the same if we are to be able to do anything.
3717 Then see if we have constants. If not, the same must be true for
3719 if (volatilep
|| ll_inner
== 0 || rl_inner
== 0
3720 || ! operand_equal_p (ll_inner
, rl_inner
, 0))
3723 if (TREE_CODE (lr_arg
) == INTEGER_CST
3724 && TREE_CODE (rr_arg
) == INTEGER_CST
)
3725 l_const
= lr_arg
, r_const
= rr_arg
;
3726 else if (lr_inner
== 0 || rr_inner
== 0
3727 || ! operand_equal_p (lr_inner
, rr_inner
, 0))
3730 l_const
= r_const
= 0;
3732 /* If either comparison code is not correct for our logical operation,
3733 fail. However, we can convert a one-bit comparison against zero into
3734 the opposite comparison against that bit being set in the field. */
3736 wanted_code
= (code
== TRUTH_AND_EXPR
? EQ_EXPR
: NE_EXPR
);
3737 if (lcode
!= wanted_code
)
3739 if (l_const
&& integer_zerop (l_const
) && integer_pow2p (ll_mask
))
3741 /* Make the left operand unsigned, since we are only interested
3742 in the value of one bit. Otherwise we are doing the wrong
3751 /* This is analogous to the code for l_const above. */
3752 if (rcode
!= wanted_code
)
3754 if (r_const
&& integer_zerop (r_const
) && integer_pow2p (rl_mask
))
3763 /* After this point all optimizations will generate bit-field
3764 references, which we might not want. */
3765 if (! (*lang_hooks
.can_use_bit_fields_p
) ())
3768 /* See if we can find a mode that contains both fields being compared on
3769 the left. If we can't, fail. Otherwise, update all constants and masks
3770 to be relative to a field of that size. */
3771 first_bit
= MIN (ll_bitpos
, rl_bitpos
);
3772 end_bit
= MAX (ll_bitpos
+ ll_bitsize
, rl_bitpos
+ rl_bitsize
);
3773 lnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3774 TYPE_ALIGN (TREE_TYPE (ll_inner
)), word_mode
,
3776 if (lnmode
== VOIDmode
)
3779 lnbitsize
= GET_MODE_BITSIZE (lnmode
);
3780 lnbitpos
= first_bit
& ~ (lnbitsize
- 1);
3781 lntype
= (*lang_hooks
.types
.type_for_size
) (lnbitsize
, 1);
3782 xll_bitpos
= ll_bitpos
- lnbitpos
, xrl_bitpos
= rl_bitpos
- lnbitpos
;
3784 if (BYTES_BIG_ENDIAN
)
3786 xll_bitpos
= lnbitsize
- xll_bitpos
- ll_bitsize
;
3787 xrl_bitpos
= lnbitsize
- xrl_bitpos
- rl_bitsize
;
3790 ll_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, ll_mask
),
3791 size_int (xll_bitpos
), 0);
3792 rl_mask
= const_binop (LSHIFT_EXPR
, convert (lntype
, rl_mask
),
3793 size_int (xrl_bitpos
), 0);
3797 l_const
= convert (lntype
, l_const
);
3798 l_const
= unextend (l_const
, ll_bitsize
, ll_unsignedp
, ll_and_mask
);
3799 l_const
= const_binop (LSHIFT_EXPR
, l_const
, size_int (xll_bitpos
), 0);
3800 if (! integer_zerop (const_binop (BIT_AND_EXPR
, l_const
,
3801 fold (build1 (BIT_NOT_EXPR
,
3805 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3807 return convert (truth_type
,
3808 wanted_code
== NE_EXPR
3809 ? integer_one_node
: integer_zero_node
);
3814 r_const
= convert (lntype
, r_const
);
3815 r_const
= unextend (r_const
, rl_bitsize
, rl_unsignedp
, rl_and_mask
);
3816 r_const
= const_binop (LSHIFT_EXPR
, r_const
, size_int (xrl_bitpos
), 0);
3817 if (! integer_zerop (const_binop (BIT_AND_EXPR
, r_const
,
3818 fold (build1 (BIT_NOT_EXPR
,
3822 warning ("comparison is always %d", wanted_code
== NE_EXPR
);
3824 return convert (truth_type
,
3825 wanted_code
== NE_EXPR
3826 ? integer_one_node
: integer_zero_node
);
3830 /* If the right sides are not constant, do the same for it. Also,
3831 disallow this optimization if a size or signedness mismatch occurs
3832 between the left and right sides. */
3835 if (ll_bitsize
!= lr_bitsize
|| rl_bitsize
!= rr_bitsize
3836 || ll_unsignedp
!= lr_unsignedp
|| rl_unsignedp
!= rr_unsignedp
3837 /* Make sure the two fields on the right
3838 correspond to the left without being swapped. */
3839 || ll_bitpos
- rl_bitpos
!= lr_bitpos
- rr_bitpos
)
3842 first_bit
= MIN (lr_bitpos
, rr_bitpos
);
3843 end_bit
= MAX (lr_bitpos
+ lr_bitsize
, rr_bitpos
+ rr_bitsize
);
3844 rnmode
= get_best_mode (end_bit
- first_bit
, first_bit
,
3845 TYPE_ALIGN (TREE_TYPE (lr_inner
)), word_mode
,
3847 if (rnmode
== VOIDmode
)
3850 rnbitsize
= GET_MODE_BITSIZE (rnmode
);
3851 rnbitpos
= first_bit
& ~ (rnbitsize
- 1);
3852 rntype
= (*lang_hooks
.types
.type_for_size
) (rnbitsize
, 1);
3853 xlr_bitpos
= lr_bitpos
- rnbitpos
, xrr_bitpos
= rr_bitpos
- rnbitpos
;
3855 if (BYTES_BIG_ENDIAN
)
3857 xlr_bitpos
= rnbitsize
- xlr_bitpos
- lr_bitsize
;
3858 xrr_bitpos
= rnbitsize
- xrr_bitpos
- rr_bitsize
;
3861 lr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, lr_mask
),
3862 size_int (xlr_bitpos
), 0);
3863 rr_mask
= const_binop (LSHIFT_EXPR
, convert (rntype
, rr_mask
),
3864 size_int (xrr_bitpos
), 0);
3866 /* Make a mask that corresponds to both fields being compared.
3867 Do this for both items being compared. If the operands are the
3868 same size and the bits being compared are in the same position
3869 then we can do this by masking both and comparing the masked
3871 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3872 lr_mask
= const_binop (BIT_IOR_EXPR
, lr_mask
, rr_mask
, 0);
3873 if (lnbitsize
== rnbitsize
&& xll_bitpos
== xlr_bitpos
)
3875 lhs
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3876 ll_unsignedp
|| rl_unsignedp
);
3877 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3878 lhs
= build (BIT_AND_EXPR
, lntype
, lhs
, ll_mask
);
3880 rhs
= make_bit_field_ref (lr_inner
, rntype
, rnbitsize
, rnbitpos
,
3881 lr_unsignedp
|| rr_unsignedp
);
3882 if (! all_ones_mask_p (lr_mask
, rnbitsize
))
3883 rhs
= build (BIT_AND_EXPR
, rntype
, rhs
, lr_mask
);
3885 return build (wanted_code
, truth_type
, lhs
, rhs
);
3888 /* There is still another way we can do something: If both pairs of
3889 fields being compared are adjacent, we may be able to make a wider
3890 field containing them both.
3892 Note that we still must mask the lhs/rhs expressions. Furthermore,
3893 the mask must be shifted to account for the shift done by
3894 make_bit_field_ref. */
3895 if ((ll_bitsize
+ ll_bitpos
== rl_bitpos
3896 && lr_bitsize
+ lr_bitpos
== rr_bitpos
)
3897 || (ll_bitpos
== rl_bitpos
+ rl_bitsize
3898 && lr_bitpos
== rr_bitpos
+ rr_bitsize
))
3902 lhs
= make_bit_field_ref (ll_inner
, lntype
, ll_bitsize
+ rl_bitsize
,
3903 MIN (ll_bitpos
, rl_bitpos
), ll_unsignedp
);
3904 rhs
= make_bit_field_ref (lr_inner
, rntype
, lr_bitsize
+ rr_bitsize
,
3905 MIN (lr_bitpos
, rr_bitpos
), lr_unsignedp
);
3907 ll_mask
= const_binop (RSHIFT_EXPR
, ll_mask
,
3908 size_int (MIN (xll_bitpos
, xrl_bitpos
)), 0);
3909 lr_mask
= const_binop (RSHIFT_EXPR
, lr_mask
,
3910 size_int (MIN (xlr_bitpos
, xrr_bitpos
)), 0);
3912 /* Convert to the smaller type before masking out unwanted bits. */
3914 if (lntype
!= rntype
)
3916 if (lnbitsize
> rnbitsize
)
3918 lhs
= convert (rntype
, lhs
);
3919 ll_mask
= convert (rntype
, ll_mask
);
3922 else if (lnbitsize
< rnbitsize
)
3924 rhs
= convert (lntype
, rhs
);
3925 lr_mask
= convert (lntype
, lr_mask
);
3930 if (! all_ones_mask_p (ll_mask
, ll_bitsize
+ rl_bitsize
))
3931 lhs
= build (BIT_AND_EXPR
, type
, lhs
, ll_mask
);
3933 if (! all_ones_mask_p (lr_mask
, lr_bitsize
+ rr_bitsize
))
3934 rhs
= build (BIT_AND_EXPR
, type
, rhs
, lr_mask
);
3936 return build (wanted_code
, truth_type
, lhs
, rhs
);
3942 /* Handle the case of comparisons with constants. If there is something in
3943 common between the masks, those bits of the constants must be the same.
3944 If not, the condition is always false. Test for this to avoid generating
3945 incorrect code below. */
3946 result
= const_binop (BIT_AND_EXPR
, ll_mask
, rl_mask
, 0);
3947 if (! integer_zerop (result
)
3948 && simple_cst_equal (const_binop (BIT_AND_EXPR
, result
, l_const
, 0),
3949 const_binop (BIT_AND_EXPR
, result
, r_const
, 0)) != 1)
3951 if (wanted_code
== NE_EXPR
)
3953 warning ("`or' of unmatched not-equal tests is always 1");
3954 return convert (truth_type
, integer_one_node
);
3958 warning ("`and' of mutually exclusive equal-tests is always 0");
3959 return convert (truth_type
, integer_zero_node
);
3963 /* Construct the expression we will return. First get the component
3964 reference we will make. Unless the mask is all ones the width of
3965 that field, perform the mask operation. Then compare with the
3967 result
= make_bit_field_ref (ll_inner
, lntype
, lnbitsize
, lnbitpos
,
3968 ll_unsignedp
|| rl_unsignedp
);
3970 ll_mask
= const_binop (BIT_IOR_EXPR
, ll_mask
, rl_mask
, 0);
3971 if (! all_ones_mask_p (ll_mask
, lnbitsize
))
3972 result
= build (BIT_AND_EXPR
, lntype
, result
, ll_mask
);
3974 return build (wanted_code
, truth_type
, result
,
3975 const_binop (BIT_IOR_EXPR
, l_const
, r_const
, 0));
3978 /* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
3982 optimize_minmax_comparison (t
)
3985 tree type
= TREE_TYPE (t
);
3986 tree arg0
= TREE_OPERAND (t
, 0);
3987 enum tree_code op_code
;
3988 tree comp_const
= TREE_OPERAND (t
, 1);
3990 int consts_equal
, consts_lt
;
3993 STRIP_SIGN_NOPS (arg0
);
3995 op_code
= TREE_CODE (arg0
);
3996 minmax_const
= TREE_OPERAND (arg0
, 1);
3997 consts_equal
= tree_int_cst_equal (minmax_const
, comp_const
);
3998 consts_lt
= tree_int_cst_lt (minmax_const
, comp_const
);
3999 inner
= TREE_OPERAND (arg0
, 0);
4001 /* If something does not permit us to optimize, return the original tree. */
4002 if ((op_code
!= MIN_EXPR
&& op_code
!= MAX_EXPR
)
4003 || TREE_CODE (comp_const
) != INTEGER_CST
4004 || TREE_CONSTANT_OVERFLOW (comp_const
)
4005 || TREE_CODE (minmax_const
) != INTEGER_CST
4006 || TREE_CONSTANT_OVERFLOW (minmax_const
))
4009 /* Now handle all the various comparison codes. We only handle EQ_EXPR
4010 and GT_EXPR, doing the rest with recursive calls using logical
4012 switch (TREE_CODE (t
))
4014 case NE_EXPR
: case LT_EXPR
: case LE_EXPR
:
4016 invert_truthvalue (optimize_minmax_comparison (invert_truthvalue (t
)));
4020 fold (build (TRUTH_ORIF_EXPR
, type
,
4021 optimize_minmax_comparison
4022 (build (EQ_EXPR
, type
, arg0
, comp_const
)),
4023 optimize_minmax_comparison
4024 (build (GT_EXPR
, type
, arg0
, comp_const
))));
4027 if (op_code
== MAX_EXPR
&& consts_equal
)
4028 /* MAX (X, 0) == 0 -> X <= 0 */
4029 return fold (build (LE_EXPR
, type
, inner
, comp_const
));
4031 else if (op_code
== MAX_EXPR
&& consts_lt
)
4032 /* MAX (X, 0) == 5 -> X == 5 */
4033 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4035 else if (op_code
== MAX_EXPR
)
4036 /* MAX (X, 0) == -1 -> false */
4037 return omit_one_operand (type
, integer_zero_node
, inner
);
4039 else if (consts_equal
)
4040 /* MIN (X, 0) == 0 -> X >= 0 */
4041 return fold (build (GE_EXPR
, type
, inner
, comp_const
));
4044 /* MIN (X, 0) == 5 -> false */
4045 return omit_one_operand (type
, integer_zero_node
, inner
);
4048 /* MIN (X, 0) == -1 -> X == -1 */
4049 return fold (build (EQ_EXPR
, type
, inner
, comp_const
));
4052 if (op_code
== MAX_EXPR
&& (consts_equal
|| consts_lt
))
4053 /* MAX (X, 0) > 0 -> X > 0
4054 MAX (X, 0) > 5 -> X > 5 */
4055 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4057 else if (op_code
== MAX_EXPR
)
4058 /* MAX (X, 0) > -1 -> true */
4059 return omit_one_operand (type
, integer_one_node
, inner
);
4061 else if (op_code
== MIN_EXPR
&& (consts_equal
|| consts_lt
))
4062 /* MIN (X, 0) > 0 -> false
4063 MIN (X, 0) > 5 -> false */
4064 return omit_one_operand (type
, integer_zero_node
, inner
);
4067 /* MIN (X, 0) > -1 -> X > -1 */
4068 return fold (build (GT_EXPR
, type
, inner
, comp_const
));
4075 /* T is an integer expression that is being multiplied, divided, or taken a
4076 modulus (CODE says which and what kind of divide or modulus) by a
4077 constant C. See if we can eliminate that operation by folding it with
4078 other operations already in T. WIDE_TYPE, if non-null, is a type that
4079 should be used for the computation if wider than our type.
4081 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
4082 (X * 2) + (Y * 4). We must, however, be assured that either the original
4083 expression would not overflow or that overflow is undefined for the type
4084 in the language in question.
4086 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
4087 the machine has a multiply-accumulate insn or that this is part of an
4088 addressing calculation.
4090 If we return a non-null expression, it is an equivalent form of the
4091 original computation, but need not be in the original type. */
4094 extract_muldiv (t
, c
, code
, wide_type
)
4097 enum tree_code code
;
4100 /* To avoid exponential search depth, refuse to allow recursion past
4101 three levels. Beyond that (1) it's highly unlikely that we'll find
4102 something interesting and (2) we've probably processed it before
4103 when we built the inner expression. */
4112 ret
= extract_muldiv_1 (t
, c
, code
, wide_type
);
4119 extract_muldiv_1 (t
, c
, code
, wide_type
)
4122 enum tree_code code
;
4125 tree type
= TREE_TYPE (t
);
4126 enum tree_code tcode
= TREE_CODE (t
);
4127 tree ctype
= (wide_type
!= 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type
))
4128 > GET_MODE_SIZE (TYPE_MODE (type
)))
4129 ? wide_type
: type
);
4131 int same_p
= tcode
== code
;
4132 tree op0
= NULL_TREE
, op1
= NULL_TREE
;
4134 /* Don't deal with constants of zero here; they confuse the code below. */
4135 if (integer_zerop (c
))
4138 if (TREE_CODE_CLASS (tcode
) == '1')
4139 op0
= TREE_OPERAND (t
, 0);
4141 if (TREE_CODE_CLASS (tcode
) == '2')
4142 op0
= TREE_OPERAND (t
, 0), op1
= TREE_OPERAND (t
, 1);
4144 /* Note that we need not handle conditional operations here since fold
4145 already handles those cases. So just do arithmetic here. */
4149 /* For a constant, we can always simplify if we are a multiply
4150 or (for divide and modulus) if it is a multiple of our constant. */
4151 if (code
== MULT_EXPR
4152 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, t
, c
, 0)))
4153 return const_binop (code
, convert (ctype
, t
), convert (ctype
, c
), 0);
4156 case CONVERT_EXPR
: case NON_LVALUE_EXPR
: case NOP_EXPR
:
4157 /* If op0 is an expression ... */
4158 if ((TREE_CODE_CLASS (TREE_CODE (op0
)) == '<'
4159 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '1'
4160 || TREE_CODE_CLASS (TREE_CODE (op0
)) == '2'
4161 || TREE_CODE_CLASS (TREE_CODE (op0
)) == 'e')
4162 /* ... and is unsigned, and its type is smaller than ctype,
4163 then we cannot pass through as widening. */
4164 && ((TREE_UNSIGNED (TREE_TYPE (op0
))
4165 && ! (TREE_CODE (TREE_TYPE (op0
)) == INTEGER_TYPE
4166 && TYPE_IS_SIZETYPE (TREE_TYPE (op0
)))
4167 && (GET_MODE_SIZE (TYPE_MODE (ctype
))
4168 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
)))))
4169 /* ... or its type is larger than ctype,
4170 then we cannot pass through this truncation. */
4171 || (GET_MODE_SIZE (TYPE_MODE (ctype
))
4172 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0
))))))
4175 /* Pass the constant down and see if we can make a simplification. If
4176 we can, replace this expression with the inner simplification for
4177 possible later conversion to our or some other type. */
4178 if (0 != (t1
= extract_muldiv (op0
, convert (TREE_TYPE (op0
), c
), code
,
4179 code
== MULT_EXPR
? ctype
: NULL_TREE
)))
4183 case NEGATE_EXPR
: case ABS_EXPR
:
4184 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4185 return fold (build1 (tcode
, ctype
, convert (ctype
, t1
)));
4188 case MIN_EXPR
: case MAX_EXPR
:
4189 /* If widening the type changes the signedness, then we can't perform
4190 this optimization as that changes the result. */
4191 if (TREE_UNSIGNED (ctype
) != TREE_UNSIGNED (type
))
4194 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
4195 if ((t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0
4196 && (t2
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4198 if (tree_int_cst_sgn (c
) < 0)
4199 tcode
= (tcode
== MIN_EXPR
? MAX_EXPR
: MIN_EXPR
);
4201 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4202 convert (ctype
, t2
)));
4206 case WITH_RECORD_EXPR
:
4207 if ((t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
, wide_type
)) != 0)
4208 return build (WITH_RECORD_EXPR
, TREE_TYPE (t1
), t1
,
4209 TREE_OPERAND (t
, 1));
4213 /* If this has not been evaluated and the operand has no side effects,
4214 we can see if we can do something inside it and make a new one.
4215 Note that this test is overly conservative since we can do this
4216 if the only reason it had side effects is that it was another
4217 similar SAVE_EXPR, but that isn't worth bothering with. */
4218 if (SAVE_EXPR_RTL (t
) == 0 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (t
, 0))
4219 && 0 != (t1
= extract_muldiv (TREE_OPERAND (t
, 0), c
, code
,
4222 t1
= save_expr (t1
);
4223 if (SAVE_EXPR_PERSISTENT_P (t
) && TREE_CODE (t1
) == SAVE_EXPR
)
4224 SAVE_EXPR_PERSISTENT_P (t1
) = 1;
4225 if (is_pending_size (t
))
4226 put_pending_size (t1
);
4231 case LSHIFT_EXPR
: case RSHIFT_EXPR
:
4232 /* If the second operand is constant, this is a multiplication
4233 or floor division, by a power of two, so we can treat it that
4234 way unless the multiplier or divisor overflows. */
4235 if (TREE_CODE (op1
) == INTEGER_CST
4236 /* const_binop may not detect overflow correctly,
4237 so check for it explicitly here. */
4238 && TYPE_PRECISION (TREE_TYPE (size_one_node
)) > TREE_INT_CST_LOW (op1
)
4239 && TREE_INT_CST_HIGH (op1
) == 0
4240 && 0 != (t1
= convert (ctype
,
4241 const_binop (LSHIFT_EXPR
, size_one_node
,
4243 && ! TREE_OVERFLOW (t1
))
4244 return extract_muldiv (build (tcode
== LSHIFT_EXPR
4245 ? MULT_EXPR
: FLOOR_DIV_EXPR
,
4246 ctype
, convert (ctype
, op0
), t1
),
4247 c
, code
, wide_type
);
4250 case PLUS_EXPR
: case MINUS_EXPR
:
4251 /* See if we can eliminate the operation on both sides. If we can, we
4252 can return a new PLUS or MINUS. If we can't, the only remaining
4253 cases where we can do anything are if the second operand is a
4255 t1
= extract_muldiv (op0
, c
, code
, wide_type
);
4256 t2
= extract_muldiv (op1
, c
, code
, wide_type
);
4257 if (t1
!= 0 && t2
!= 0
4258 && (code
== MULT_EXPR
4259 /* If not multiplication, we can only do this if both operands
4260 are divisible by c. */
4261 || (multiple_of_p (ctype
, op0
, c
)
4262 && multiple_of_p (ctype
, op1
, c
))))
4263 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4264 convert (ctype
, t2
)));
4266 /* If this was a subtraction, negate OP1 and set it to be an addition.
4267 This simplifies the logic below. */
4268 if (tcode
== MINUS_EXPR
)
4269 tcode
= PLUS_EXPR
, op1
= negate_expr (op1
);
4271 if (TREE_CODE (op1
) != INTEGER_CST
)
4274 /* If either OP1 or C are negative, this optimization is not safe for
4275 some of the division and remainder types while for others we need
4276 to change the code. */
4277 if (tree_int_cst_sgn (op1
) < 0 || tree_int_cst_sgn (c
) < 0)
4279 if (code
== CEIL_DIV_EXPR
)
4280 code
= FLOOR_DIV_EXPR
;
4281 else if (code
== FLOOR_DIV_EXPR
)
4282 code
= CEIL_DIV_EXPR
;
4283 else if (code
!= MULT_EXPR
4284 && code
!= CEIL_MOD_EXPR
&& code
!= FLOOR_MOD_EXPR
)
4288 /* If it's a multiply or a division/modulus operation of a multiple
4289 of our constant, do the operation and verify it doesn't overflow. */
4290 if (code
== MULT_EXPR
4291 || integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4293 op1
= const_binop (code
, convert (ctype
, op1
), convert (ctype
, c
), 0);
4294 if (op1
== 0 || TREE_OVERFLOW (op1
))
4300 /* If we have an unsigned type is not a sizetype, we cannot widen
4301 the operation since it will change the result if the original
4302 computation overflowed. */
4303 if (TREE_UNSIGNED (ctype
)
4304 && ! (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
))
4308 /* If we were able to eliminate our operation from the first side,
4309 apply our operation to the second side and reform the PLUS. */
4310 if (t1
!= 0 && (TREE_CODE (t1
) != code
|| code
== MULT_EXPR
))
4311 return fold (build (tcode
, ctype
, convert (ctype
, t1
), op1
));
4313 /* The last case is if we are a multiply. In that case, we can
4314 apply the distributive law to commute the multiply and addition
4315 if the multiplication of the constants doesn't overflow. */
4316 if (code
== MULT_EXPR
)
4317 return fold (build (tcode
, ctype
, fold (build (code
, ctype
,
4318 convert (ctype
, op0
),
4319 convert (ctype
, c
))),
4325 /* We have a special case here if we are doing something like
4326 (C * 8) % 4 since we know that's zero. */
4327 if ((code
== TRUNC_MOD_EXPR
|| code
== CEIL_MOD_EXPR
4328 || code
== FLOOR_MOD_EXPR
|| code
== ROUND_MOD_EXPR
)
4329 && TREE_CODE (TREE_OPERAND (t
, 1)) == INTEGER_CST
4330 && integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4331 return omit_one_operand (type
, integer_zero_node
, op0
);
4333 /* Arrange for the code below to simplify two constants first. */
4334 if (TREE_CODE (op1
) == INTEGER_CST
&& TREE_CODE (op0
) != INTEGER_CST
)
4341 /* ... fall through ... */
4343 case TRUNC_DIV_EXPR
: case CEIL_DIV_EXPR
: case FLOOR_DIV_EXPR
:
4344 case ROUND_DIV_EXPR
: case EXACT_DIV_EXPR
:
4345 /* If we can extract our operation from the LHS, do so and return a
4346 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
4347 do something only if the second operand is a constant. */
4349 && (t1
= extract_muldiv (op0
, c
, code
, wide_type
)) != 0)
4350 return fold (build (tcode
, ctype
, convert (ctype
, t1
),
4351 convert (ctype
, op1
)));
4352 else if (tcode
== MULT_EXPR
&& code
== MULT_EXPR
4353 && (t1
= extract_muldiv (op1
, c
, code
, wide_type
)) != 0)
4354 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4355 convert (ctype
, t1
)));
4356 else if (TREE_CODE (op1
) != INTEGER_CST
)
4359 /* If these are the same operation types, we can associate them
4360 assuming no overflow. */
4362 && 0 != (t1
= const_binop (MULT_EXPR
, convert (ctype
, op1
),
4363 convert (ctype
, c
), 0))
4364 && ! TREE_OVERFLOW (t1
))
4365 return fold (build (tcode
, ctype
, convert (ctype
, op0
), t1
));
4367 /* If these operations "cancel" each other, we have the main
4368 optimizations of this pass, which occur when either constant is a
4369 multiple of the other, in which case we replace this with either an
4370 operation or CODE or TCODE.
4372 If we have an unsigned type that is not a sizetype, we cannot do
4373 this since it will change the result if the original computation
4375 if ((! TREE_UNSIGNED (ctype
)
4376 || (TREE_CODE (ctype
) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (ctype
)))
4377 && ((code
== MULT_EXPR
&& tcode
== EXACT_DIV_EXPR
)
4378 || (tcode
== MULT_EXPR
4379 && code
!= TRUNC_MOD_EXPR
&& code
!= CEIL_MOD_EXPR
4380 && code
!= FLOOR_MOD_EXPR
&& code
!= ROUND_MOD_EXPR
)))
4382 if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, op1
, c
, 0)))
4383 return fold (build (tcode
, ctype
, convert (ctype
, op0
),
4385 const_binop (TRUNC_DIV_EXPR
,
4387 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR
, c
, op1
, 0)))
4388 return fold (build (code
, ctype
, convert (ctype
, op0
),
4390 const_binop (TRUNC_DIV_EXPR
,
4402 /* If T contains a COMPOUND_EXPR which was inserted merely to evaluate
4403 S, a SAVE_EXPR, return the expression actually being evaluated. Note
4404 that we may sometimes modify the tree. */
4407 strip_compound_expr (t
, s
)
4411 enum tree_code code
= TREE_CODE (t
);
4413 /* See if this is the COMPOUND_EXPR we want to eliminate. */
4414 if (code
== COMPOUND_EXPR
&& TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
4415 && TREE_OPERAND (TREE_OPERAND (t
, 0), 0) == s
)
4416 return TREE_OPERAND (t
, 1);
4418 /* See if this is a COND_EXPR or a simple arithmetic operator. We
4419 don't bother handling any other types. */
4420 else if (code
== COND_EXPR
)
4422 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4423 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4424 TREE_OPERAND (t
, 2) = strip_compound_expr (TREE_OPERAND (t
, 2), s
);
4426 else if (TREE_CODE_CLASS (code
) == '1')
4427 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4428 else if (TREE_CODE_CLASS (code
) == '<'
4429 || TREE_CODE_CLASS (code
) == '2')
4431 TREE_OPERAND (t
, 0) = strip_compound_expr (TREE_OPERAND (t
, 0), s
);
4432 TREE_OPERAND (t
, 1) = strip_compound_expr (TREE_OPERAND (t
, 1), s
);
4438 /* Return a node which has the indicated constant VALUE (either 0 or
4439 1), and is of the indicated TYPE. */
4442 constant_boolean_node (value
, type
)
4446 if (type
== integer_type_node
)
4447 return value
? integer_one_node
: integer_zero_node
;
4448 else if (TREE_CODE (type
) == BOOLEAN_TYPE
)
4449 return (*lang_hooks
.truthvalue_conversion
) (value
? integer_one_node
:
4453 tree t
= build_int_2 (value
, 0);
4455 TREE_TYPE (t
) = type
;
4460 /* Utility function for the following routine, to see how complex a nesting of
4461 COND_EXPRs can be. EXPR is the expression and LIMIT is a count beyond which
4462 we don't care (to avoid spending too much time on complex expressions.). */
4465 count_cond (expr
, lim
)
4471 if (TREE_CODE (expr
) != COND_EXPR
)
4476 ctrue
= count_cond (TREE_OPERAND (expr
, 1), lim
- 1);
4477 cfalse
= count_cond (TREE_OPERAND (expr
, 2), lim
- 1 - ctrue
);
4478 return MIN (lim
, 1 + ctrue
+ cfalse
);
4481 /* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
4482 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
4483 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
4484 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
4485 COND is the first argument to CODE; otherwise (as in the example
4486 given here), it is the second argument. TYPE is the type of the
4487 original expression. */
4490 fold_binary_op_with_conditional_arg (code
, type
, cond
, arg
, cond_first_p
)
4491 enum tree_code code
;
4497 tree test
, true_value
, false_value
;
4498 tree lhs
= NULL_TREE
;
4499 tree rhs
= NULL_TREE
;
4500 /* In the end, we'll produce a COND_EXPR. Both arms of the
4501 conditional expression will be binary operations. The left-hand
4502 side of the expression to be executed if the condition is true
4503 will be pointed to by TRUE_LHS. Similarly, the right-hand side
4504 of the expression to be executed if the condition is true will be
4505 pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
4506 but apply to the expression to be executed if the conditional is
4512 /* These are the codes to use for the left-hand side and right-hand
4513 side of the COND_EXPR. Normally, they are the same as CODE. */
4514 enum tree_code lhs_code
= code
;
4515 enum tree_code rhs_code
= code
;
4516 /* And these are the types of the expressions. */
4517 tree lhs_type
= type
;
4518 tree rhs_type
= type
;
4523 true_rhs
= false_rhs
= &arg
;
4524 true_lhs
= &true_value
;
4525 false_lhs
= &false_value
;
4529 true_lhs
= false_lhs
= &arg
;
4530 true_rhs
= &true_value
;
4531 false_rhs
= &false_value
;
4534 if (TREE_CODE (cond
) == COND_EXPR
)
4536 test
= TREE_OPERAND (cond
, 0);
4537 true_value
= TREE_OPERAND (cond
, 1);
4538 false_value
= TREE_OPERAND (cond
, 2);
4539 /* If this operand throws an expression, then it does not make
4540 sense to try to perform a logical or arithmetic operation
4541 involving it. Instead of building `a + throw 3' for example,
4542 we simply build `a, throw 3'. */
4543 if (VOID_TYPE_P (TREE_TYPE (true_value
)))
4547 lhs_code
= COMPOUND_EXPR
;
4548 lhs_type
= void_type_node
;
4553 if (VOID_TYPE_P (TREE_TYPE (false_value
)))
4557 rhs_code
= COMPOUND_EXPR
;
4558 rhs_type
= void_type_node
;
4566 tree testtype
= TREE_TYPE (cond
);
4568 true_value
= convert (testtype
, integer_one_node
);
4569 false_value
= convert (testtype
, integer_zero_node
);
4572 /* If ARG is complex we want to make sure we only evaluate
4573 it once. Though this is only required if it is volatile, it
4574 might be more efficient even if it is not. However, if we
4575 succeed in folding one part to a constant, we do not need
4576 to make this SAVE_EXPR. Since we do this optimization
4577 primarily to see if we do end up with constant and this
4578 SAVE_EXPR interferes with later optimizations, suppressing
4579 it when we can is important.
4581 If we are not in a function, we can't make a SAVE_EXPR, so don't
4582 try to do so. Don't try to see if the result is a constant
4583 if an arm is a COND_EXPR since we get exponential behavior
4586 if (TREE_CODE (arg
) == SAVE_EXPR
)
4588 else if (lhs
== 0 && rhs
== 0
4589 && !TREE_CONSTANT (arg
)
4590 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
4591 && ((TREE_CODE (arg
) != VAR_DECL
&& TREE_CODE (arg
) != PARM_DECL
)
4592 || TREE_SIDE_EFFECTS (arg
)))
4594 if (TREE_CODE (true_value
) != COND_EXPR
)
4595 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4597 if (TREE_CODE (false_value
) != COND_EXPR
)
4598 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4600 if ((lhs
== 0 || ! TREE_CONSTANT (lhs
))
4601 && (rhs
== 0 || !TREE_CONSTANT (rhs
)))
4603 arg
= save_expr (arg
);
4610 lhs
= fold (build (lhs_code
, lhs_type
, *true_lhs
, *true_rhs
));
4612 rhs
= fold (build (rhs_code
, rhs_type
, *false_lhs
, *false_rhs
));
4614 test
= fold (build (COND_EXPR
, type
, test
, lhs
, rhs
));
4617 return build (COMPOUND_EXPR
, type
,
4618 convert (void_type_node
, arg
),
4619 strip_compound_expr (test
, arg
));
4621 return convert (type
, test
);
4625 /* Subroutine of fold() that checks for the addition of +/- 0.0.
4627 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
4628 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
4629 ADDEND is the same as X.
4631 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
4632 and finite. The problematic cases are when X is zero, and its mode
4633 has signed zeros. In the case of rounding towards -infinity,
4634 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
4635 modes, X + 0 is not the same as X because -0 + 0 is 0. */
4638 fold_real_zero_addition_p (type
, addend
, negate
)
4642 if (!real_zerop (addend
))
4645 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
4646 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type
)))
4649 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
4650 if (TREE_CODE (addend
) == REAL_CST
4651 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend
)))
4654 /* The mode has signed zeros, and we have to honor their sign.
4655 In this situation, there is only one case we can return true for.
4656 X - 0 is the same as X unless rounding towards -infinity is
4658 return negate
&& !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type
));
4662 /* Perform constant folding and related simplification of EXPR.
4663 The related simplifications include x*1 => x, x*0 => 0, etc.,
4664 and application of the associative law.
4665 NOP_EXPR conversions may be removed freely (as long as we
4666 are careful not to change the C type of the overall expression)
4667 We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
4668 but we can constant-fold them if they have constant operands. */
4675 tree t1
= NULL_TREE
;
4677 tree type
= TREE_TYPE (expr
);
4678 tree arg0
= NULL_TREE
, arg1
= NULL_TREE
;
4679 enum tree_code code
= TREE_CODE (t
);
4680 int kind
= TREE_CODE_CLASS (code
);
4682 /* WINS will be nonzero when the switch is done
4683 if all operands are constant. */
4686 /* Don't try to process an RTL_EXPR since its operands aren't trees.
4687 Likewise for a SAVE_EXPR that's already been evaluated. */
4688 if (code
== RTL_EXPR
|| (code
== SAVE_EXPR
&& SAVE_EXPR_RTL (t
) != 0))
4691 /* Return right away if a constant. */
4695 #ifdef MAX_INTEGER_COMPUTATION_MODE
4696 check_max_integer_computation_mode (expr
);
4699 if (code
== NOP_EXPR
|| code
== FLOAT_EXPR
|| code
== CONVERT_EXPR
)
4703 /* Special case for conversion ops that can have fixed point args. */
4704 arg0
= TREE_OPERAND (t
, 0);
4706 /* Don't use STRIP_NOPS, because signedness of argument type matters. */
4708 STRIP_SIGN_NOPS (arg0
);
4710 if (arg0
!= 0 && TREE_CODE (arg0
) == COMPLEX_CST
)
4711 subop
= TREE_REALPART (arg0
);
4715 if (subop
!= 0 && TREE_CODE (subop
) != INTEGER_CST
4716 && TREE_CODE (subop
) != REAL_CST
4718 /* Note that TREE_CONSTANT isn't enough:
4719 static var addresses are constant but we can't
4720 do arithmetic on them. */
4723 else if (IS_EXPR_CODE_CLASS (kind
) || kind
== 'r')
4725 int len
= first_rtl_op (code
);
4727 for (i
= 0; i
< len
; i
++)
4729 tree op
= TREE_OPERAND (t
, i
);
4733 continue; /* Valid for CALL_EXPR, at least. */
4735 if (kind
== '<' || code
== RSHIFT_EXPR
)
4737 /* Signedness matters here. Perhaps we can refine this
4739 STRIP_SIGN_NOPS (op
);
4742 /* Strip any conversions that don't change the mode. */
4745 if (TREE_CODE (op
) == COMPLEX_CST
)
4746 subop
= TREE_REALPART (op
);
4750 if (TREE_CODE (subop
) != INTEGER_CST
4751 && TREE_CODE (subop
) != REAL_CST
)
4752 /* Note that TREE_CONSTANT isn't enough:
4753 static var addresses are constant but we can't
4754 do arithmetic on them. */
4764 /* If this is a commutative operation, and ARG0 is a constant, move it
4765 to ARG1 to reduce the number of tests below. */
4766 if ((code
== PLUS_EXPR
|| code
== MULT_EXPR
|| code
== MIN_EXPR
4767 || code
== MAX_EXPR
|| code
== BIT_IOR_EXPR
|| code
== BIT_XOR_EXPR
4768 || code
== BIT_AND_EXPR
)
4769 && (TREE_CODE (arg0
) == INTEGER_CST
|| TREE_CODE (arg0
) == REAL_CST
))
4771 tem
= arg0
; arg0
= arg1
; arg1
= tem
;
4773 tem
= TREE_OPERAND (t
, 0); TREE_OPERAND (t
, 0) = TREE_OPERAND (t
, 1);
4774 TREE_OPERAND (t
, 1) = tem
;
4777 /* Now WINS is set as described above,
4778 ARG0 is the first operand of EXPR,
4779 and ARG1 is the second operand (if it has more than one operand).
4781 First check for cases where an arithmetic operation is applied to a
4782 compound, conditional, or comparison operation. Push the arithmetic
4783 operation inside the compound or conditional to see if any folding
4784 can then be done. Convert comparison to conditional for this purpose.
4785 The also optimizes non-constant cases that used to be done in
4788 Before we do that, see if this is a BIT_AND_EXPR or a BIT_IOR_EXPR,
4789 one of the operands is a comparison and the other is a comparison, a
4790 BIT_AND_EXPR with the constant 1, or a truth value. In that case, the
4791 code below would make the expression more complex. Change it to a
4792 TRUTH_{AND,OR}_EXPR. Likewise, convert a similar NE_EXPR to
4793 TRUTH_XOR_EXPR and an EQ_EXPR to the inversion of a TRUTH_XOR_EXPR. */
4795 if ((code
== BIT_AND_EXPR
|| code
== BIT_IOR_EXPR
4796 || code
== EQ_EXPR
|| code
== NE_EXPR
)
4797 && ((truth_value_p (TREE_CODE (arg0
))
4798 && (truth_value_p (TREE_CODE (arg1
))
4799 || (TREE_CODE (arg1
) == BIT_AND_EXPR
4800 && integer_onep (TREE_OPERAND (arg1
, 1)))))
4801 || (truth_value_p (TREE_CODE (arg1
))
4802 && (truth_value_p (TREE_CODE (arg0
))
4803 || (TREE_CODE (arg0
) == BIT_AND_EXPR
4804 && integer_onep (TREE_OPERAND (arg0
, 1)))))))
4806 t
= fold (build (code
== BIT_AND_EXPR
? TRUTH_AND_EXPR
4807 : code
== BIT_IOR_EXPR
? TRUTH_OR_EXPR
4811 if (code
== EQ_EXPR
)
4812 t
= invert_truthvalue (t
);
4817 if (TREE_CODE_CLASS (code
) == '1')
4819 if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
4820 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4821 fold (build1 (code
, type
, TREE_OPERAND (arg0
, 1))));
4822 else if (TREE_CODE (arg0
) == COND_EXPR
)
4824 tree arg01
= TREE_OPERAND (arg0
, 1);
4825 tree arg02
= TREE_OPERAND (arg0
, 2);
4826 if (! VOID_TYPE_P (TREE_TYPE (arg01
)))
4827 arg01
= fold (build1 (code
, type
, arg01
));
4828 if (! VOID_TYPE_P (TREE_TYPE (arg02
)))
4829 arg02
= fold (build1 (code
, type
, arg02
));
4830 t
= fold (build (COND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4833 /* If this was a conversion, and all we did was to move into
4834 inside the COND_EXPR, bring it back out. But leave it if
4835 it is a conversion from integer to integer and the
4836 result precision is no wider than a word since such a
4837 conversion is cheap and may be optimized away by combine,
4838 while it couldn't if it were outside the COND_EXPR. Then return
4839 so we don't get into an infinite recursion loop taking the
4840 conversion out and then back in. */
4842 if ((code
== NOP_EXPR
|| code
== CONVERT_EXPR
4843 || code
== NON_LVALUE_EXPR
)
4844 && TREE_CODE (t
) == COND_EXPR
4845 && TREE_CODE (TREE_OPERAND (t
, 1)) == code
4846 && TREE_CODE (TREE_OPERAND (t
, 2)) == code
4847 && ! VOID_TYPE_P (TREE_OPERAND (t
, 1))
4848 && ! VOID_TYPE_P (TREE_OPERAND (t
, 2))
4849 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))
4850 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 2), 0)))
4851 && ! (INTEGRAL_TYPE_P (TREE_TYPE (t
))
4853 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 1), 0))))
4854 && TYPE_PRECISION (TREE_TYPE (t
)) <= BITS_PER_WORD
))
4855 t
= build1 (code
, type
,
4857 TREE_TYPE (TREE_OPERAND
4858 (TREE_OPERAND (t
, 1), 0)),
4859 TREE_OPERAND (t
, 0),
4860 TREE_OPERAND (TREE_OPERAND (t
, 1), 0),
4861 TREE_OPERAND (TREE_OPERAND (t
, 2), 0)));
4864 else if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<')
4865 return fold (build (COND_EXPR
, type
, arg0
,
4866 fold (build1 (code
, type
, integer_one_node
)),
4867 fold (build1 (code
, type
, integer_zero_node
))));
4869 else if (TREE_CODE_CLASS (code
) == '2'
4870 || TREE_CODE_CLASS (code
) == '<')
4872 if (TREE_CODE (arg1
) == COMPOUND_EXPR
4873 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg1
, 0))
4874 && ! TREE_SIDE_EFFECTS (arg0
))
4875 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
4876 fold (build (code
, type
,
4877 arg0
, TREE_OPERAND (arg1
, 1))));
4878 else if ((TREE_CODE (arg1
) == COND_EXPR
4879 || (TREE_CODE_CLASS (TREE_CODE (arg1
)) == '<'
4880 && TREE_CODE_CLASS (code
) != '<'))
4881 && (TREE_CODE (arg0
) != COND_EXPR
4882 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
4883 && (! TREE_SIDE_EFFECTS (arg0
)
4884 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4885 && ! contains_placeholder_p (arg0
))))
4887 fold_binary_op_with_conditional_arg (code
, type
, arg1
, arg0
,
4888 /*cond_first_p=*/0);
4889 else if (TREE_CODE (arg0
) == COMPOUND_EXPR
)
4890 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4891 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
4892 else if ((TREE_CODE (arg0
) == COND_EXPR
4893 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
4894 && TREE_CODE_CLASS (code
) != '<'))
4895 && (TREE_CODE (arg1
) != COND_EXPR
4896 || count_cond (arg0
, 25) + count_cond (arg1
, 25) <= 25)
4897 && (! TREE_SIDE_EFFECTS (arg1
)
4898 || ((*lang_hooks
.decls
.global_bindings_p
) () == 0
4899 && ! contains_placeholder_p (arg1
))))
4901 fold_binary_op_with_conditional_arg (code
, type
, arg0
, arg1
,
4902 /*cond_first_p=*/1);
4904 else if (TREE_CODE_CLASS (code
) == '<'
4905 && TREE_CODE (arg0
) == COMPOUND_EXPR
)
4906 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg0
, 0),
4907 fold (build (code
, type
, TREE_OPERAND (arg0
, 1), arg1
)));
4908 else if (TREE_CODE_CLASS (code
) == '<'
4909 && TREE_CODE (arg1
) == COMPOUND_EXPR
)
4910 return build (COMPOUND_EXPR
, type
, TREE_OPERAND (arg1
, 0),
4911 fold (build (code
, type
, arg0
, TREE_OPERAND (arg1
, 1))));
4924 return fold (DECL_INITIAL (t
));
4929 case FIX_TRUNC_EXPR
:
4930 /* Other kinds of FIX are not handled properly by fold_convert. */
4932 if (TREE_TYPE (TREE_OPERAND (t
, 0)) == TREE_TYPE (t
))
4933 return TREE_OPERAND (t
, 0);
4935 /* Handle cases of two conversions in a row. */
4936 if (TREE_CODE (TREE_OPERAND (t
, 0)) == NOP_EXPR
4937 || TREE_CODE (TREE_OPERAND (t
, 0)) == CONVERT_EXPR
)
4939 tree inside_type
= TREE_TYPE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4940 tree inter_type
= TREE_TYPE (TREE_OPERAND (t
, 0));
4941 tree final_type
= TREE_TYPE (t
);
4942 int inside_int
= INTEGRAL_TYPE_P (inside_type
);
4943 int inside_ptr
= POINTER_TYPE_P (inside_type
);
4944 int inside_float
= FLOAT_TYPE_P (inside_type
);
4945 unsigned int inside_prec
= TYPE_PRECISION (inside_type
);
4946 int inside_unsignedp
= TREE_UNSIGNED (inside_type
);
4947 int inter_int
= INTEGRAL_TYPE_P (inter_type
);
4948 int inter_ptr
= POINTER_TYPE_P (inter_type
);
4949 int inter_float
= FLOAT_TYPE_P (inter_type
);
4950 unsigned int inter_prec
= TYPE_PRECISION (inter_type
);
4951 int inter_unsignedp
= TREE_UNSIGNED (inter_type
);
4952 int final_int
= INTEGRAL_TYPE_P (final_type
);
4953 int final_ptr
= POINTER_TYPE_P (final_type
);
4954 int final_float
= FLOAT_TYPE_P (final_type
);
4955 unsigned int final_prec
= TYPE_PRECISION (final_type
);
4956 int final_unsignedp
= TREE_UNSIGNED (final_type
);
4958 /* In addition to the cases of two conversions in a row
4959 handled below, if we are converting something to its own
4960 type via an object of identical or wider precision, neither
4961 conversion is needed. */
4962 if (TYPE_MAIN_VARIANT (inside_type
) == TYPE_MAIN_VARIANT (final_type
)
4963 && ((inter_int
&& final_int
) || (inter_float
&& final_float
))
4964 && inter_prec
>= final_prec
)
4965 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4967 /* Likewise, if the intermediate and final types are either both
4968 float or both integer, we don't need the middle conversion if
4969 it is wider than the final type and doesn't change the signedness
4970 (for integers). Avoid this if the final type is a pointer
4971 since then we sometimes need the inner conversion. Likewise if
4972 the outer has a precision not equal to the size of its mode. */
4973 if ((((inter_int
|| inter_ptr
) && (inside_int
|| inside_ptr
))
4974 || (inter_float
&& inside_float
))
4975 && inter_prec
>= inside_prec
4976 && (inter_float
|| inter_unsignedp
== inside_unsignedp
)
4977 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
4978 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
4980 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4982 /* If we have a sign-extension of a zero-extended value, we can
4983 replace that by a single zero-extension. */
4984 if (inside_int
&& inter_int
&& final_int
4985 && inside_prec
< inter_prec
&& inter_prec
< final_prec
4986 && inside_unsignedp
&& !inter_unsignedp
)
4987 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
4989 /* Two conversions in a row are not needed unless:
4990 - some conversion is floating-point (overstrict for now), or
4991 - the intermediate type is narrower than both initial and
4993 - the intermediate type and innermost type differ in signedness,
4994 and the outermost type is wider than the intermediate, or
4995 - the initial type is a pointer type and the precisions of the
4996 intermediate and final types differ, or
4997 - the final type is a pointer type and the precisions of the
4998 initial and intermediate types differ. */
4999 if (! inside_float
&& ! inter_float
&& ! final_float
5000 && (inter_prec
> inside_prec
|| inter_prec
> final_prec
)
5001 && ! (inside_int
&& inter_int
5002 && inter_unsignedp
!= inside_unsignedp
5003 && inter_prec
< final_prec
)
5004 && ((inter_unsignedp
&& inter_prec
> inside_prec
)
5005 == (final_unsignedp
&& final_prec
> inter_prec
))
5006 && ! (inside_ptr
&& inter_prec
!= final_prec
)
5007 && ! (final_ptr
&& inside_prec
!= inter_prec
)
5008 && ! (final_prec
!= GET_MODE_BITSIZE (TYPE_MODE (final_type
))
5009 && TYPE_MODE (final_type
) == TYPE_MODE (inter_type
))
5011 return convert (final_type
, TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5014 if (TREE_CODE (TREE_OPERAND (t
, 0)) == MODIFY_EXPR
5015 && TREE_CONSTANT (TREE_OPERAND (TREE_OPERAND (t
, 0), 1))
5016 /* Detect assigning a bitfield. */
5017 && !(TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 0)) == COMPONENT_REF
5018 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (TREE_OPERAND (t
, 0), 0), 1))))
5020 /* Don't leave an assignment inside a conversion
5021 unless assigning a bitfield. */
5022 tree prev
= TREE_OPERAND (t
, 0);
5023 TREE_OPERAND (t
, 0) = TREE_OPERAND (prev
, 1);
5024 /* First do the assignment, then return converted constant. */
5025 t
= build (COMPOUND_EXPR
, TREE_TYPE (t
), prev
, fold (t
));
5030 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
5031 constants (if x has signed type, the sign bit cannot be set
5032 in c). This folds extension into the BIT_AND_EXPR. */
5033 if (INTEGRAL_TYPE_P (TREE_TYPE (t
))
5034 && TREE_CODE (TREE_TYPE (t
)) != BOOLEAN_TYPE
5035 && TREE_CODE (TREE_OPERAND (t
, 0)) == BIT_AND_EXPR
5036 && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t
, 0), 1)) == INTEGER_CST
)
5038 tree
and = TREE_OPERAND (t
, 0);
5039 tree and0
= TREE_OPERAND (and, 0), and1
= TREE_OPERAND (and, 1);
5042 if (TREE_UNSIGNED (TREE_TYPE (and))
5043 || (TYPE_PRECISION (TREE_TYPE (t
))
5044 <= TYPE_PRECISION (TREE_TYPE (and))))
5046 else if (TYPE_PRECISION (TREE_TYPE (and1
))
5047 <= HOST_BITS_PER_WIDE_INT
5048 && host_integerp (and1
, 1))
5050 unsigned HOST_WIDE_INT cst
;
5052 cst
= tree_low_cst (and1
, 1);
5053 cst
&= (HOST_WIDE_INT
) -1
5054 << (TYPE_PRECISION (TREE_TYPE (and1
)) - 1);
5055 change
= (cst
== 0);
5056 #ifdef LOAD_EXTEND_OP
5058 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0
)))
5061 tree uns
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (and0
));
5062 and0
= convert (uns
, and0
);
5063 and1
= convert (uns
, and1
);
5068 return fold (build (BIT_AND_EXPR
, TREE_TYPE (t
),
5069 convert (TREE_TYPE (t
), and0
),
5070 convert (TREE_TYPE (t
), and1
)));
5075 TREE_CONSTANT (t
) = TREE_CONSTANT (arg0
);
5078 return fold_convert (t
, arg0
);
5080 case VIEW_CONVERT_EXPR
:
5081 if (TREE_CODE (TREE_OPERAND (t
, 0)) == VIEW_CONVERT_EXPR
)
5082 return build1 (VIEW_CONVERT_EXPR
, type
,
5083 TREE_OPERAND (TREE_OPERAND (t
, 0), 0));
5087 if (TREE_CODE (arg0
) == CONSTRUCTOR
)
5089 tree m
= purpose_member (arg1
, CONSTRUCTOR_ELTS (arg0
));
5096 TREE_CONSTANT (t
) = wins
;
5102 if (TREE_CODE (arg0
) == INTEGER_CST
)
5104 unsigned HOST_WIDE_INT low
;
5106 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5107 TREE_INT_CST_HIGH (arg0
),
5109 t
= build_int_2 (low
, high
);
5110 TREE_TYPE (t
) = type
;
5112 = (TREE_OVERFLOW (arg0
)
5113 | force_fit_type (t
, overflow
&& !TREE_UNSIGNED (type
)));
5114 TREE_CONSTANT_OVERFLOW (t
)
5115 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5117 else if (TREE_CODE (arg0
) == REAL_CST
)
5118 t
= build_real (type
, REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5120 else if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5121 return TREE_OPERAND (arg0
, 0);
5122 /* Convert -((double)float) into (double)(-float). */
5123 else if (TREE_CODE (arg0
) == NOP_EXPR
5124 && TREE_CODE (type
) == REAL_TYPE
)
5126 tree targ0
= strip_float_extensions (arg0
);
5128 return convert (type
, build1 (NEGATE_EXPR
, TREE_TYPE (targ0
), targ0
));
5132 /* Convert - (a - b) to (b - a) for non-floating-point. */
5133 else if (TREE_CODE (arg0
) == MINUS_EXPR
5134 && (! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
))
5135 return build (MINUS_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5136 TREE_OPERAND (arg0
, 0));
5143 if (TREE_CODE (arg0
) == INTEGER_CST
)
5145 /* If the value is unsigned, then the absolute value is
5146 the same as the ordinary value. */
5147 if (TREE_UNSIGNED (type
))
5149 /* Similarly, if the value is non-negative. */
5150 else if (INT_CST_LT (integer_minus_one_node
, arg0
))
5152 /* If the value is negative, then the absolute value is
5156 unsigned HOST_WIDE_INT low
;
5158 int overflow
= neg_double (TREE_INT_CST_LOW (arg0
),
5159 TREE_INT_CST_HIGH (arg0
),
5161 t
= build_int_2 (low
, high
);
5162 TREE_TYPE (t
) = type
;
5164 = (TREE_OVERFLOW (arg0
)
5165 | force_fit_type (t
, overflow
));
5166 TREE_CONSTANT_OVERFLOW (t
)
5167 = TREE_OVERFLOW (t
) | TREE_CONSTANT_OVERFLOW (arg0
);
5170 else if (TREE_CODE (arg0
) == REAL_CST
)
5172 if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg0
)))
5173 t
= build_real (type
,
5174 REAL_VALUE_NEGATE (TREE_REAL_CST (arg0
)));
5177 else if (TREE_CODE (arg0
) == ABS_EXPR
|| TREE_CODE (arg0
) == NEGATE_EXPR
)
5178 return build1 (ABS_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5179 /* Convert fabs((double)float) into (double)fabsf(float). */
5180 else if (TREE_CODE (arg0
) == NOP_EXPR
5181 && TREE_CODE (type
) == REAL_TYPE
)
5183 tree targ0
= strip_float_extensions (arg0
);
5185 return convert (type
, build1 (ABS_EXPR
, TREE_TYPE (targ0
), targ0
));
5190 /* fabs(sqrt(x)) = sqrt(x) and fabs(exp(x)) = exp(x). */
5191 enum built_in_function fcode
= builtin_mathfn_code (arg0
);
5192 if (fcode
== BUILT_IN_SQRT
5193 || fcode
== BUILT_IN_SQRTF
5194 || fcode
== BUILT_IN_SQRTL
5195 || fcode
== BUILT_IN_EXP
5196 || fcode
== BUILT_IN_EXPF
5197 || fcode
== BUILT_IN_EXPL
)
5203 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
5204 return convert (type
, arg0
);
5205 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
5206 return build (COMPLEX_EXPR
, type
,
5207 TREE_OPERAND (arg0
, 0),
5208 negate_expr (TREE_OPERAND (arg0
, 1)));
5209 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
5210 return build_complex (type
, TREE_REALPART (arg0
),
5211 negate_expr (TREE_IMAGPART (arg0
)));
5212 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
5213 return fold (build (TREE_CODE (arg0
), type
,
5214 fold (build1 (CONJ_EXPR
, type
,
5215 TREE_OPERAND (arg0
, 0))),
5216 fold (build1 (CONJ_EXPR
,
5217 type
, TREE_OPERAND (arg0
, 1)))));
5218 else if (TREE_CODE (arg0
) == CONJ_EXPR
)
5219 return TREE_OPERAND (arg0
, 0);
5225 t
= build_int_2 (~ TREE_INT_CST_LOW (arg0
),
5226 ~ TREE_INT_CST_HIGH (arg0
));
5227 TREE_TYPE (t
) = type
;
5228 force_fit_type (t
, 0);
5229 TREE_OVERFLOW (t
) = TREE_OVERFLOW (arg0
);
5230 TREE_CONSTANT_OVERFLOW (t
) = TREE_CONSTANT_OVERFLOW (arg0
);
5232 else if (TREE_CODE (arg0
) == BIT_NOT_EXPR
)
5233 return TREE_OPERAND (arg0
, 0);
5237 /* A + (-B) -> A - B */
5238 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5239 return fold (build (MINUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5240 /* (-A) + B -> B - A */
5241 if (TREE_CODE (arg0
) == NEGATE_EXPR
)
5242 return fold (build (MINUS_EXPR
, type
, arg1
, TREE_OPERAND (arg0
, 0)));
5243 else if (! FLOAT_TYPE_P (type
))
5245 if (integer_zerop (arg1
))
5246 return non_lvalue (convert (type
, arg0
));
5248 /* If we are adding two BIT_AND_EXPR's, both of which are and'ing
5249 with a constant, and the two constants have no bits in common,
5250 we should treat this as a BIT_IOR_EXPR since this may produce more
5252 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5253 && TREE_CODE (arg1
) == BIT_AND_EXPR
5254 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5255 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5256 && integer_zerop (const_binop (BIT_AND_EXPR
,
5257 TREE_OPERAND (arg0
, 1),
5258 TREE_OPERAND (arg1
, 1), 0)))
5260 code
= BIT_IOR_EXPR
;
5264 /* Reassociate (plus (plus (mult) (foo)) (mult)) as
5265 (plus (plus (mult) (mult)) (foo)) so that we can
5266 take advantage of the factoring cases below. */
5267 if ((TREE_CODE (arg0
) == PLUS_EXPR
5268 && TREE_CODE (arg1
) == MULT_EXPR
)
5269 || (TREE_CODE (arg1
) == PLUS_EXPR
5270 && TREE_CODE (arg0
) == MULT_EXPR
))
5272 tree parg0
, parg1
, parg
, marg
;
5274 if (TREE_CODE (arg0
) == PLUS_EXPR
)
5275 parg
= arg0
, marg
= arg1
;
5277 parg
= arg1
, marg
= arg0
;
5278 parg0
= TREE_OPERAND (parg
, 0);
5279 parg1
= TREE_OPERAND (parg
, 1);
5283 if (TREE_CODE (parg0
) == MULT_EXPR
5284 && TREE_CODE (parg1
) != MULT_EXPR
)
5285 return fold (build (PLUS_EXPR
, type
,
5286 fold (build (PLUS_EXPR
, type
, parg0
, marg
)),
5288 if (TREE_CODE (parg0
) != MULT_EXPR
5289 && TREE_CODE (parg1
) == MULT_EXPR
)
5290 return fold (build (PLUS_EXPR
, type
,
5291 fold (build (PLUS_EXPR
, type
, parg1
, marg
)),
5295 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
)
5297 tree arg00
, arg01
, arg10
, arg11
;
5298 tree alt0
= NULL_TREE
, alt1
= NULL_TREE
, same
;
5300 /* (A * C) + (B * C) -> (A+B) * C.
5301 We are most concerned about the case where C is a constant,
5302 but other combinations show up during loop reduction. Since
5303 it is not difficult, try all four possibilities. */
5305 arg00
= TREE_OPERAND (arg0
, 0);
5306 arg01
= TREE_OPERAND (arg0
, 1);
5307 arg10
= TREE_OPERAND (arg1
, 0);
5308 arg11
= TREE_OPERAND (arg1
, 1);
5311 if (operand_equal_p (arg01
, arg11
, 0))
5312 same
= arg01
, alt0
= arg00
, alt1
= arg10
;
5313 else if (operand_equal_p (arg00
, arg10
, 0))
5314 same
= arg00
, alt0
= arg01
, alt1
= arg11
;
5315 else if (operand_equal_p (arg00
, arg11
, 0))
5316 same
= arg00
, alt0
= arg01
, alt1
= arg10
;
5317 else if (operand_equal_p (arg01
, arg10
, 0))
5318 same
= arg01
, alt0
= arg00
, alt1
= arg11
;
5320 /* No identical multiplicands; see if we can find a common
5321 power-of-two factor in non-power-of-two multiplies. This
5322 can help in multi-dimensional array access. */
5323 else if (TREE_CODE (arg01
) == INTEGER_CST
5324 && TREE_CODE (arg11
) == INTEGER_CST
5325 && TREE_INT_CST_HIGH (arg01
) == 0
5326 && TREE_INT_CST_HIGH (arg11
) == 0)
5328 HOST_WIDE_INT int01
, int11
, tmp
;
5329 int01
= TREE_INT_CST_LOW (arg01
);
5330 int11
= TREE_INT_CST_LOW (arg11
);
5332 /* Move min of absolute values to int11. */
5333 if ((int01
>= 0 ? int01
: -int01
)
5334 < (int11
>= 0 ? int11
: -int11
))
5336 tmp
= int01
, int01
= int11
, int11
= tmp
;
5337 alt0
= arg00
, arg00
= arg10
, arg10
= alt0
;
5338 alt0
= arg01
, arg01
= arg11
, arg11
= alt0
;
5341 if (exact_log2 (int11
) > 0 && int01
% int11
== 0)
5343 alt0
= fold (build (MULT_EXPR
, type
, arg00
,
5344 build_int_2 (int01
/ int11
, 0)));
5351 return fold (build (MULT_EXPR
, type
,
5352 fold (build (PLUS_EXPR
, type
, alt0
, alt1
)),
5357 /* See if ARG1 is zero and X + ARG1 reduces to X. */
5358 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 0))
5359 return non_lvalue (convert (type
, arg0
));
5361 /* Likewise if the operands are reversed. */
5362 else if (fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5363 return non_lvalue (convert (type
, arg1
));
5366 /* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
5367 is a rotate of A by C1 bits. */
5368 /* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
5369 is a rotate of A by B bits. */
5371 enum tree_code code0
, code1
;
5372 code0
= TREE_CODE (arg0
);
5373 code1
= TREE_CODE (arg1
);
5374 if (((code0
== RSHIFT_EXPR
&& code1
== LSHIFT_EXPR
)
5375 || (code1
== RSHIFT_EXPR
&& code0
== LSHIFT_EXPR
))
5376 && operand_equal_p (TREE_OPERAND (arg0
, 0),
5377 TREE_OPERAND (arg1
, 0), 0)
5378 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5380 tree tree01
, tree11
;
5381 enum tree_code code01
, code11
;
5383 tree01
= TREE_OPERAND (arg0
, 1);
5384 tree11
= TREE_OPERAND (arg1
, 1);
5385 STRIP_NOPS (tree01
);
5386 STRIP_NOPS (tree11
);
5387 code01
= TREE_CODE (tree01
);
5388 code11
= TREE_CODE (tree11
);
5389 if (code01
== INTEGER_CST
5390 && code11
== INTEGER_CST
5391 && TREE_INT_CST_HIGH (tree01
) == 0
5392 && TREE_INT_CST_HIGH (tree11
) == 0
5393 && ((TREE_INT_CST_LOW (tree01
) + TREE_INT_CST_LOW (tree11
))
5394 == TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)))))
5395 return build (LROTATE_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5396 code0
== LSHIFT_EXPR
? tree01
: tree11
);
5397 else if (code11
== MINUS_EXPR
)
5399 tree tree110
, tree111
;
5400 tree110
= TREE_OPERAND (tree11
, 0);
5401 tree111
= TREE_OPERAND (tree11
, 1);
5402 STRIP_NOPS (tree110
);
5403 STRIP_NOPS (tree111
);
5404 if (TREE_CODE (tree110
) == INTEGER_CST
5405 && 0 == compare_tree_int (tree110
,
5407 (TREE_TYPE (TREE_OPERAND
5409 && operand_equal_p (tree01
, tree111
, 0))
5410 return build ((code0
== LSHIFT_EXPR
5413 type
, TREE_OPERAND (arg0
, 0), tree01
);
5415 else if (code01
== MINUS_EXPR
)
5417 tree tree010
, tree011
;
5418 tree010
= TREE_OPERAND (tree01
, 0);
5419 tree011
= TREE_OPERAND (tree01
, 1);
5420 STRIP_NOPS (tree010
);
5421 STRIP_NOPS (tree011
);
5422 if (TREE_CODE (tree010
) == INTEGER_CST
5423 && 0 == compare_tree_int (tree010
,
5425 (TREE_TYPE (TREE_OPERAND
5427 && operand_equal_p (tree11
, tree011
, 0))
5428 return build ((code0
!= LSHIFT_EXPR
5431 type
, TREE_OPERAND (arg0
, 0), tree11
);
5437 /* In most languages, can't associate operations on floats through
5438 parentheses. Rather than remember where the parentheses were, we
5439 don't associate floats at all. It shouldn't matter much. However,
5440 associating multiplications is only very slightly inaccurate, so do
5441 that if -funsafe-math-optimizations is specified. */
5444 && (! FLOAT_TYPE_P (type
)
5445 || (flag_unsafe_math_optimizations
&& code
== MULT_EXPR
)))
5447 tree var0
, con0
, lit0
, minus_lit0
;
5448 tree var1
, con1
, lit1
, minus_lit1
;
5450 /* Split both trees into variables, constants, and literals. Then
5451 associate each group together, the constants with literals,
5452 then the result with variables. This increases the chances of
5453 literals being recombined later and of generating relocatable
5454 expressions for the sum of a constant and literal. */
5455 var0
= split_tree (arg0
, code
, &con0
, &lit0
, &minus_lit0
, 0);
5456 var1
= split_tree (arg1
, code
, &con1
, &lit1
, &minus_lit1
,
5457 code
== MINUS_EXPR
);
5459 /* Only do something if we found more than two objects. Otherwise,
5460 nothing has changed and we risk infinite recursion. */
5461 if (2 < ((var0
!= 0) + (var1
!= 0)
5462 + (con0
!= 0) + (con1
!= 0)
5463 + (lit0
!= 0) + (lit1
!= 0)
5464 + (minus_lit0
!= 0) + (minus_lit1
!= 0)))
5466 /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
5467 if (code
== MINUS_EXPR
)
5470 var0
= associate_trees (var0
, var1
, code
, type
);
5471 con0
= associate_trees (con0
, con1
, code
, type
);
5472 lit0
= associate_trees (lit0
, lit1
, code
, type
);
5473 minus_lit0
= associate_trees (minus_lit0
, minus_lit1
, code
, type
);
5475 /* Preserve the MINUS_EXPR if the negative part of the literal is
5476 greater than the positive part. Otherwise, the multiplicative
5477 folding code (i.e extract_muldiv) may be fooled in case
5478 unsigned constants are substracted, like in the following
5479 example: ((X*2 + 4) - 8U)/2. */
5480 if (minus_lit0
&& lit0
)
5482 if (tree_int_cst_lt (lit0
, minus_lit0
))
5484 minus_lit0
= associate_trees (minus_lit0
, lit0
,
5490 lit0
= associate_trees (lit0
, minus_lit0
,
5498 return convert (type
, associate_trees (var0
, minus_lit0
,
5502 con0
= associate_trees (con0
, minus_lit0
,
5504 return convert (type
, associate_trees (var0
, con0
,
5509 con0
= associate_trees (con0
, lit0
, code
, type
);
5510 return convert (type
, associate_trees (var0
, con0
, code
, type
));
5516 t1
= const_binop (code
, arg0
, arg1
, 0);
5517 if (t1
!= NULL_TREE
)
5519 /* The return value should always have
5520 the same type as the original expression. */
5521 if (TREE_TYPE (t1
) != TREE_TYPE (t
))
5522 t1
= convert (TREE_TYPE (t
), t1
);
5529 /* A - (-B) -> A + B */
5530 if (TREE_CODE (arg1
) == NEGATE_EXPR
)
5531 return fold (build (PLUS_EXPR
, type
, arg0
, TREE_OPERAND (arg1
, 0)));
5532 /* (-A) - B -> (-B) - A where B is easily negated and we can swap. */
5533 if (TREE_CODE (arg0
) == NEGATE_EXPR
5534 && FLOAT_TYPE_P (type
)
5535 && negate_expr_p (arg1
)
5536 && (! TREE_SIDE_EFFECTS (arg0
) || TREE_CONSTANT (arg1
))
5537 && (! TREE_SIDE_EFFECTS (arg1
) || TREE_CONSTANT (arg0
)))
5538 return fold (build (MINUS_EXPR
, type
, negate_expr (arg1
),
5539 TREE_OPERAND (arg0
, 0)));
5541 if (! FLOAT_TYPE_P (type
))
5543 if (! wins
&& integer_zerop (arg0
))
5544 return negate_expr (convert (type
, arg1
));
5545 if (integer_zerop (arg1
))
5546 return non_lvalue (convert (type
, arg0
));
5548 /* (A * C) - (B * C) -> (A-B) * C. Since we are most concerned
5549 about the case where C is a constant, just try one of the
5550 four possibilities. */
5552 if (TREE_CODE (arg0
) == MULT_EXPR
&& TREE_CODE (arg1
) == MULT_EXPR
5553 && operand_equal_p (TREE_OPERAND (arg0
, 1),
5554 TREE_OPERAND (arg1
, 1), 0))
5555 return fold (build (MULT_EXPR
, type
,
5556 fold (build (MINUS_EXPR
, type
,
5557 TREE_OPERAND (arg0
, 0),
5558 TREE_OPERAND (arg1
, 0))),
5559 TREE_OPERAND (arg0
, 1)));
5562 /* See if ARG1 is zero and X - ARG1 reduces to X. */
5563 else if (fold_real_zero_addition_p (TREE_TYPE (arg0
), arg1
, 1))
5564 return non_lvalue (convert (type
, arg0
));
5566 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
5567 ARG0 is zero and X + ARG0 reduces to X, since that would mean
5568 (-ARG1 + ARG0) reduces to -ARG1. */
5569 else if (!wins
&& fold_real_zero_addition_p (TREE_TYPE (arg1
), arg0
, 0))
5570 return negate_expr (convert (type
, arg1
));
5572 /* Fold &x - &x. This can happen from &x.foo - &x.
5573 This is unsafe for certain floats even in non-IEEE formats.
5574 In IEEE, it is unsafe because it does wrong for NaNs.
5575 Also note that operand_equal_p is always false if an operand
5578 if ((! FLOAT_TYPE_P (type
) || flag_unsafe_math_optimizations
)
5579 && operand_equal_p (arg0
, arg1
, 0))
5580 return convert (type
, integer_zero_node
);
5585 /* (-A) * (-B) -> A * B */
5586 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5587 return fold (build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5588 TREE_OPERAND (arg1
, 0)));
5590 if (! FLOAT_TYPE_P (type
))
5592 if (integer_zerop (arg1
))
5593 return omit_one_operand (type
, arg1
, arg0
);
5594 if (integer_onep (arg1
))
5595 return non_lvalue (convert (type
, arg0
));
5597 /* (a * (1 << b)) is (a << b) */
5598 if (TREE_CODE (arg1
) == LSHIFT_EXPR
5599 && integer_onep (TREE_OPERAND (arg1
, 0)))
5600 return fold (build (LSHIFT_EXPR
, type
, arg0
,
5601 TREE_OPERAND (arg1
, 1)));
5602 if (TREE_CODE (arg0
) == LSHIFT_EXPR
5603 && integer_onep (TREE_OPERAND (arg0
, 0)))
5604 return fold (build (LSHIFT_EXPR
, type
, arg1
,
5605 TREE_OPERAND (arg0
, 1)));
5607 if (TREE_CODE (arg1
) == INTEGER_CST
5608 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5610 return convert (type
, tem
);
5615 /* Maybe fold x * 0 to 0. The expressions aren't the same
5616 when x is NaN, since x * 0 is also NaN. Nor are they the
5617 same in modes with signed zeros, since multiplying a
5618 negative value by 0 gives -0, not +0. */
5619 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0
)))
5620 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0
)))
5621 && real_zerop (arg1
))
5622 return omit_one_operand (type
, arg1
, arg0
);
5623 /* In IEEE floating point, x*1 is not equivalent to x for snans. */
5624 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5625 && real_onep (arg1
))
5626 return non_lvalue (convert (type
, arg0
));
5628 /* Transform x * -1.0 into -x. */
5629 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5630 && real_minus_onep (arg1
))
5631 return fold (build1 (NEGATE_EXPR
, type
, arg0
));
5634 if (! wins
&& real_twop (arg1
)
5635 && (*lang_hooks
.decls
.global_bindings_p
) () == 0
5636 && ! contains_placeholder_p (arg0
))
5638 tree arg
= save_expr (arg0
);
5639 return build (PLUS_EXPR
, type
, arg
, arg
);
5642 if (flag_unsafe_math_optimizations
)
5644 enum built_in_function fcode0
= builtin_mathfn_code (arg0
);
5645 enum built_in_function fcode1
= builtin_mathfn_code (arg1
);
5647 /* Optimize sqrt(x)*sqrt(y) as sqrt(x*y). */
5648 if ((fcode0
== BUILT_IN_SQRT
&& fcode1
== BUILT_IN_SQRT
)
5649 || (fcode0
== BUILT_IN_SQRTF
&& fcode1
== BUILT_IN_SQRTF
)
5650 || (fcode0
== BUILT_IN_SQRTL
&& fcode1
== BUILT_IN_SQRTL
))
5652 tree sqrtfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5653 tree arg
= build (MULT_EXPR
, type
,
5654 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5655 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5656 tree arglist
= build_tree_list (NULL_TREE
, arg
);
5657 return fold (build_function_call_expr (sqrtfn
, arglist
));
5660 /* Optimize exp(x)*exp(y) as exp(x+y). */
5661 if ((fcode0
== BUILT_IN_EXP
&& fcode1
== BUILT_IN_EXP
)
5662 || (fcode0
== BUILT_IN_EXPF
&& fcode1
== BUILT_IN_EXPF
)
5663 || (fcode0
== BUILT_IN_EXPL
&& fcode1
== BUILT_IN_EXPL
))
5665 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
5666 tree arg
= build (PLUS_EXPR
, type
,
5667 TREE_VALUE (TREE_OPERAND (arg0
, 1)),
5668 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5669 tree arglist
= build_tree_list (NULL_TREE
, arg
);
5670 return fold (build_function_call_expr (expfn
, arglist
));
5678 if (integer_all_onesp (arg1
))
5679 return omit_one_operand (type
, arg1
, arg0
);
5680 if (integer_zerop (arg1
))
5681 return non_lvalue (convert (type
, arg0
));
5682 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5683 if (t1
!= NULL_TREE
)
5686 /* Convert (or (not arg0) (not arg1)) to (not (and (arg0) (arg1))).
5688 This results in more efficient code for machines without a NAND
5689 instruction. Combine will canonicalize to the first form
5690 which will allow use of NAND instructions provided by the
5691 backend if they exist. */
5692 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5693 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5695 return fold (build1 (BIT_NOT_EXPR
, type
,
5696 build (BIT_AND_EXPR
, type
,
5697 TREE_OPERAND (arg0
, 0),
5698 TREE_OPERAND (arg1
, 0))));
5701 /* See if this can be simplified into a rotate first. If that
5702 is unsuccessful continue in the association code. */
5706 if (integer_zerop (arg1
))
5707 return non_lvalue (convert (type
, arg0
));
5708 if (integer_all_onesp (arg1
))
5709 return fold (build1 (BIT_NOT_EXPR
, type
, arg0
));
5711 /* If we are XORing two BIT_AND_EXPR's, both of which are and'ing
5712 with a constant, and the two constants have no bits in common,
5713 we should treat this as a BIT_IOR_EXPR since this may produce more
5715 if (TREE_CODE (arg0
) == BIT_AND_EXPR
5716 && TREE_CODE (arg1
) == BIT_AND_EXPR
5717 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5718 && TREE_CODE (TREE_OPERAND (arg1
, 1)) == INTEGER_CST
5719 && integer_zerop (const_binop (BIT_AND_EXPR
,
5720 TREE_OPERAND (arg0
, 1),
5721 TREE_OPERAND (arg1
, 1), 0)))
5723 code
= BIT_IOR_EXPR
;
5727 /* See if this can be simplified into a rotate first. If that
5728 is unsuccessful continue in the association code. */
5733 if (integer_all_onesp (arg1
))
5734 return non_lvalue (convert (type
, arg0
));
5735 if (integer_zerop (arg1
))
5736 return omit_one_operand (type
, arg1
, arg0
);
5737 t1
= distribute_bit_expr (code
, type
, arg0
, arg1
);
5738 if (t1
!= NULL_TREE
)
5740 /* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
5741 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) == NOP_EXPR
5742 && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0
, 0))))
5745 = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg0
, 0)));
5747 if (prec
< BITS_PER_WORD
&& prec
< HOST_BITS_PER_WIDE_INT
5748 && (~TREE_INT_CST_LOW (arg1
)
5749 & (((HOST_WIDE_INT
) 1 << prec
) - 1)) == 0)
5750 return build1 (NOP_EXPR
, type
, TREE_OPERAND (arg0
, 0));
5753 /* Convert (and (not arg0) (not arg1)) to (not (or (arg0) (arg1))).
5755 This results in more efficient code for machines without a NOR
5756 instruction. Combine will canonicalize to the first form
5757 which will allow use of NOR instructions provided by the
5758 backend if they exist. */
5759 if (TREE_CODE (arg0
) == BIT_NOT_EXPR
5760 && TREE_CODE (arg1
) == BIT_NOT_EXPR
)
5762 return fold (build1 (BIT_NOT_EXPR
, type
,
5763 build (BIT_IOR_EXPR
, type
,
5764 TREE_OPERAND (arg0
, 0),
5765 TREE_OPERAND (arg1
, 0))));
5770 case BIT_ANDTC_EXPR
:
5771 if (integer_all_onesp (arg0
))
5772 return non_lvalue (convert (type
, arg1
));
5773 if (integer_zerop (arg0
))
5774 return omit_one_operand (type
, arg0
, arg1
);
5775 if (TREE_CODE (arg1
) == INTEGER_CST
)
5777 arg1
= fold (build1 (BIT_NOT_EXPR
, type
, arg1
));
5778 code
= BIT_AND_EXPR
;
5784 /* Don't touch a floating-point divide by zero unless the mode
5785 of the constant can represent infinity. */
5786 if (TREE_CODE (arg1
) == REAL_CST
5787 && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1
)))
5788 && real_zerop (arg1
))
5791 /* (-A) / (-B) -> A / B */
5792 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == NEGATE_EXPR
)
5793 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5794 TREE_OPERAND (arg1
, 0)));
5796 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
5797 if (!HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0
)))
5798 && real_onep (arg1
))
5799 return non_lvalue (convert (type
, arg0
));
5801 /* If ARG1 is a constant, we can convert this to a multiply by the
5802 reciprocal. This does not have the same rounding properties,
5803 so only do this if -funsafe-math-optimizations. We can actually
5804 always safely do it if ARG1 is a power of two, but it's hard to
5805 tell if it is or not in a portable manner. */
5806 if (TREE_CODE (arg1
) == REAL_CST
)
5808 if (flag_unsafe_math_optimizations
5809 && 0 != (tem
= const_binop (code
, build_real (type
, dconst1
),
5811 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5812 /* Find the reciprocal if optimizing and the result is exact. */
5816 r
= TREE_REAL_CST (arg1
);
5817 if (exact_real_inverse (TYPE_MODE(TREE_TYPE(arg0
)), &r
))
5819 tem
= build_real (type
, r
);
5820 return fold (build (MULT_EXPR
, type
, arg0
, tem
));
5824 /* Convert A/B/C to A/(B*C). */
5825 if (flag_unsafe_math_optimizations
5826 && TREE_CODE (arg0
) == RDIV_EXPR
)
5828 return fold (build (RDIV_EXPR
, type
, TREE_OPERAND (arg0
, 0),
5829 build (MULT_EXPR
, type
, TREE_OPERAND (arg0
, 1),
5832 /* Convert A/(B/C) to (A/B)*C. */
5833 if (flag_unsafe_math_optimizations
5834 && TREE_CODE (arg1
) == RDIV_EXPR
)
5836 return fold (build (MULT_EXPR
, type
,
5837 build (RDIV_EXPR
, type
, arg0
,
5838 TREE_OPERAND (arg1
, 0)),
5839 TREE_OPERAND (arg1
, 1)));
5842 /* Optimize x/exp(y) into x*exp(-y). */
5843 if (flag_unsafe_math_optimizations
)
5845 enum built_in_function fcode
= builtin_mathfn_code (arg1
);
5846 if (fcode
== BUILT_IN_EXP
5847 || fcode
== BUILT_IN_EXPF
5848 || fcode
== BUILT_IN_EXPL
)
5850 tree expfn
= TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0);
5851 tree arg
= build1 (NEGATE_EXPR
, type
,
5852 TREE_VALUE (TREE_OPERAND (arg1
, 1)));
5853 tree arglist
= build_tree_list (NULL_TREE
, arg
);
5854 arg1
= build_function_call_expr (expfn
, arglist
);
5855 return fold (build (MULT_EXPR
, type
, arg0
, arg1
));
5860 case TRUNC_DIV_EXPR
:
5861 case ROUND_DIV_EXPR
:
5862 case FLOOR_DIV_EXPR
:
5864 case EXACT_DIV_EXPR
:
5865 if (integer_onep (arg1
))
5866 return non_lvalue (convert (type
, arg0
));
5867 if (integer_zerop (arg1
))
5870 /* If arg0 is a multiple of arg1, then rewrite to the fastest div
5871 operation, EXACT_DIV_EXPR.
5873 Note that only CEIL_DIV_EXPR and FLOOR_DIV_EXPR are rewritten now.
5874 At one time others generated faster code, it's not clear if they do
5875 after the last round to changes to the DIV code in expmed.c. */
5876 if ((code
== CEIL_DIV_EXPR
|| code
== FLOOR_DIV_EXPR
)
5877 && multiple_of_p (type
, arg0
, arg1
))
5878 return fold (build (EXACT_DIV_EXPR
, type
, arg0
, arg1
));
5880 if (TREE_CODE (arg1
) == INTEGER_CST
5881 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5883 return convert (type
, tem
);
5888 case FLOOR_MOD_EXPR
:
5889 case ROUND_MOD_EXPR
:
5890 case TRUNC_MOD_EXPR
:
5891 if (integer_onep (arg1
))
5892 return omit_one_operand (type
, integer_zero_node
, arg0
);
5893 if (integer_zerop (arg1
))
5896 if (TREE_CODE (arg1
) == INTEGER_CST
5897 && 0 != (tem
= extract_muldiv (TREE_OPERAND (t
, 0), arg1
,
5899 return convert (type
, tem
);
5905 if (integer_all_onesp (arg0
))
5906 return omit_one_operand (type
, arg0
, arg1
);
5910 /* Optimize -1 >> x for arithmetic right shifts. */
5911 if (integer_all_onesp (arg0
) && ! TREE_UNSIGNED (type
))
5912 return omit_one_operand (type
, arg0
, arg1
);
5913 /* ... fall through ... */
5917 if (integer_zerop (arg1
))
5918 return non_lvalue (convert (type
, arg0
));
5919 if (integer_zerop (arg0
))
5920 return omit_one_operand (type
, arg0
, arg1
);
5922 /* Since negative shift count is not well-defined,
5923 don't try to compute it in the compiler. */
5924 if (TREE_CODE (arg1
) == INTEGER_CST
&& tree_int_cst_sgn (arg1
) < 0)
5926 /* Rewrite an LROTATE_EXPR by a constant into an
5927 RROTATE_EXPR by a new constant. */
5928 if (code
== LROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
)
5930 TREE_SET_CODE (t
, RROTATE_EXPR
);
5931 code
= RROTATE_EXPR
;
5932 TREE_OPERAND (t
, 1) = arg1
5935 convert (TREE_TYPE (arg1
),
5936 build_int_2 (GET_MODE_BITSIZE (TYPE_MODE (type
)), 0)),
5938 if (tree_int_cst_sgn (arg1
) < 0)
5942 /* If we have a rotate of a bit operation with the rotate count and
5943 the second operand of the bit operation both constant,
5944 permute the two operations. */
5945 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
5946 && (TREE_CODE (arg0
) == BIT_AND_EXPR
5947 || TREE_CODE (arg0
) == BIT_ANDTC_EXPR
5948 || TREE_CODE (arg0
) == BIT_IOR_EXPR
5949 || TREE_CODE (arg0
) == BIT_XOR_EXPR
)
5950 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
5951 return fold (build (TREE_CODE (arg0
), type
,
5952 fold (build (code
, type
,
5953 TREE_OPERAND (arg0
, 0), arg1
)),
5954 fold (build (code
, type
,
5955 TREE_OPERAND (arg0
, 1), arg1
))));
5957 /* Two consecutive rotates adding up to the width of the mode can
5959 if (code
== RROTATE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
5960 && TREE_CODE (arg0
) == RROTATE_EXPR
5961 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
5962 && TREE_INT_CST_HIGH (arg1
) == 0
5963 && TREE_INT_CST_HIGH (TREE_OPERAND (arg0
, 1)) == 0
5964 && ((TREE_INT_CST_LOW (arg1
)
5965 + TREE_INT_CST_LOW (TREE_OPERAND (arg0
, 1)))
5966 == (unsigned int) GET_MODE_BITSIZE (TYPE_MODE (type
))))
5967 return TREE_OPERAND (arg0
, 0);
5972 if (operand_equal_p (arg0
, arg1
, 0))
5973 return omit_one_operand (type
, arg0
, arg1
);
5974 if (INTEGRAL_TYPE_P (type
)
5975 && operand_equal_p (arg1
, TYPE_MIN_VALUE (type
), 1))
5976 return omit_one_operand (type
, arg1
, arg0
);
5980 if (operand_equal_p (arg0
, arg1
, 0))
5981 return omit_one_operand (type
, arg0
, arg1
);
5982 if (INTEGRAL_TYPE_P (type
)
5983 && TYPE_MAX_VALUE (type
)
5984 && operand_equal_p (arg1
, TYPE_MAX_VALUE (type
), 1))
5985 return omit_one_operand (type
, arg1
, arg0
);
5988 case TRUTH_NOT_EXPR
:
5989 /* Note that the operand of this must be an int
5990 and its values must be 0 or 1.
5991 ("true" is a fixed value perhaps depending on the language,
5992 but we don't handle values other than 1 correctly yet.) */
5993 tem
= invert_truthvalue (arg0
);
5994 /* Avoid infinite recursion. */
5995 if (TREE_CODE (tem
) == TRUTH_NOT_EXPR
)
5997 return convert (type
, tem
);
5999 case TRUTH_ANDIF_EXPR
:
6000 /* Note that the operands of this must be ints
6001 and their values must be 0 or 1.
6002 ("true" is a fixed value perhaps depending on the language.) */
6003 /* If first arg is constant zero, return it. */
6004 if (integer_zerop (arg0
))
6005 return convert (type
, arg0
);
6006 case TRUTH_AND_EXPR
:
6007 /* If either arg is constant true, drop it. */
6008 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6009 return non_lvalue (convert (type
, arg1
));
6010 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
)
6011 /* Preserve sequence points. */
6012 && (code
!= TRUTH_ANDIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6013 return non_lvalue (convert (type
, arg0
));
6014 /* If second arg is constant zero, result is zero, but first arg
6015 must be evaluated. */
6016 if (integer_zerop (arg1
))
6017 return omit_one_operand (type
, arg1
, arg0
);
6018 /* Likewise for first arg, but note that only the TRUTH_AND_EXPR
6019 case will be handled here. */
6020 if (integer_zerop (arg0
))
6021 return omit_one_operand (type
, arg0
, arg1
);
6024 /* We only do these simplifications if we are optimizing. */
6028 /* Check for things like (A || B) && (A || C). We can convert this
6029 to A || (B && C). Note that either operator can be any of the four
6030 truth and/or operations and the transformation will still be
6031 valid. Also note that we only care about order for the
6032 ANDIF and ORIF operators. If B contains side effects, this
6033 might change the truth-value of A. */
6034 if (TREE_CODE (arg0
) == TREE_CODE (arg1
)
6035 && (TREE_CODE (arg0
) == TRUTH_ANDIF_EXPR
6036 || TREE_CODE (arg0
) == TRUTH_ORIF_EXPR
6037 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
6038 || TREE_CODE (arg0
) == TRUTH_OR_EXPR
)
6039 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg0
, 1)))
6041 tree a00
= TREE_OPERAND (arg0
, 0);
6042 tree a01
= TREE_OPERAND (arg0
, 1);
6043 tree a10
= TREE_OPERAND (arg1
, 0);
6044 tree a11
= TREE_OPERAND (arg1
, 1);
6045 int commutative
= ((TREE_CODE (arg0
) == TRUTH_OR_EXPR
6046 || TREE_CODE (arg0
) == TRUTH_AND_EXPR
)
6047 && (code
== TRUTH_AND_EXPR
6048 || code
== TRUTH_OR_EXPR
));
6050 if (operand_equal_p (a00
, a10
, 0))
6051 return fold (build (TREE_CODE (arg0
), type
, a00
,
6052 fold (build (code
, type
, a01
, a11
))));
6053 else if (commutative
&& operand_equal_p (a00
, a11
, 0))
6054 return fold (build (TREE_CODE (arg0
), type
, a00
,
6055 fold (build (code
, type
, a01
, a10
))));
6056 else if (commutative
&& operand_equal_p (a01
, a10
, 0))
6057 return fold (build (TREE_CODE (arg0
), type
, a01
,
6058 fold (build (code
, type
, a00
, a11
))));
6060 /* This case if tricky because we must either have commutative
6061 operators or else A10 must not have side-effects. */
6063 else if ((commutative
|| ! TREE_SIDE_EFFECTS (a10
))
6064 && operand_equal_p (a01
, a11
, 0))
6065 return fold (build (TREE_CODE (arg0
), type
,
6066 fold (build (code
, type
, a00
, a10
)),
6070 /* See if we can build a range comparison. */
6071 if (0 != (tem
= fold_range_test (t
)))
6074 /* Check for the possibility of merging component references. If our
6075 lhs is another similar operation, try to merge its rhs with our
6076 rhs. Then try to merge our lhs and rhs. */
6077 if (TREE_CODE (arg0
) == code
6078 && 0 != (tem
= fold_truthop (code
, type
,
6079 TREE_OPERAND (arg0
, 1), arg1
)))
6080 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6082 if ((tem
= fold_truthop (code
, type
, arg0
, arg1
)) != 0)
6087 case TRUTH_ORIF_EXPR
:
6088 /* Note that the operands of this must be ints
6089 and their values must be 0 or true.
6090 ("true" is a fixed value perhaps depending on the language.) */
6091 /* If first arg is constant true, return it. */
6092 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6093 return convert (type
, arg0
);
6095 /* If either arg is constant zero, drop it. */
6096 if (TREE_CODE (arg0
) == INTEGER_CST
&& integer_zerop (arg0
))
6097 return non_lvalue (convert (type
, arg1
));
6098 if (TREE_CODE (arg1
) == INTEGER_CST
&& integer_zerop (arg1
)
6099 /* Preserve sequence points. */
6100 && (code
!= TRUTH_ORIF_EXPR
|| ! TREE_SIDE_EFFECTS (arg0
)))
6101 return non_lvalue (convert (type
, arg0
));
6102 /* If second arg is constant true, result is true, but we must
6103 evaluate first arg. */
6104 if (TREE_CODE (arg1
) == INTEGER_CST
&& ! integer_zerop (arg1
))
6105 return omit_one_operand (type
, arg1
, arg0
);
6106 /* Likewise for first arg, but note this only occurs here for
6108 if (TREE_CODE (arg0
) == INTEGER_CST
&& ! integer_zerop (arg0
))
6109 return omit_one_operand (type
, arg0
, arg1
);
6112 case TRUTH_XOR_EXPR
:
6113 /* If either arg is constant zero, drop it. */
6114 if (integer_zerop (arg0
))
6115 return non_lvalue (convert (type
, arg1
));
6116 if (integer_zerop (arg1
))
6117 return non_lvalue (convert (type
, arg0
));
6118 /* If either arg is constant true, this is a logical inversion. */
6119 if (integer_onep (arg0
))
6120 return non_lvalue (convert (type
, invert_truthvalue (arg1
)));
6121 if (integer_onep (arg1
))
6122 return non_lvalue (convert (type
, invert_truthvalue (arg0
)));
6131 /* If one arg is a real or integer constant, put it last. */
6132 if ((TREE_CODE (arg0
) == INTEGER_CST
6133 && TREE_CODE (arg1
) != INTEGER_CST
)
6134 || (TREE_CODE (arg0
) == REAL_CST
6135 && TREE_CODE (arg0
) != REAL_CST
))
6137 TREE_OPERAND (t
, 0) = arg1
;
6138 TREE_OPERAND (t
, 1) = arg0
;
6139 arg0
= TREE_OPERAND (t
, 0);
6140 arg1
= TREE_OPERAND (t
, 1);
6141 code
= swap_tree_comparison (code
);
6142 TREE_SET_CODE (t
, code
);
6145 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6147 tree targ0
= strip_float_extensions (arg0
);
6148 tree targ1
= strip_float_extensions (arg1
);
6149 tree newtype
= TREE_TYPE (targ0
);
6151 if (TYPE_PRECISION (TREE_TYPE (targ1
)) > TYPE_PRECISION (newtype
))
6152 newtype
= TREE_TYPE (targ1
);
6154 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
6155 if (TYPE_PRECISION (newtype
) < TYPE_PRECISION (TREE_TYPE (arg0
)))
6156 return fold (build (code
, type
, convert (newtype
, targ0
),
6157 convert (newtype
, targ1
)));
6159 /* (-a) CMP (-b) -> b CMP a */
6160 if (TREE_CODE (arg0
) == NEGATE_EXPR
6161 && TREE_CODE (arg1
) == NEGATE_EXPR
)
6162 return fold (build (code
, type
, TREE_OPERAND (arg1
, 0),
6163 TREE_OPERAND (arg0
, 0)));
6164 /* (-a) CMP CST -> a swap(CMP) (-CST) */
6165 if (TREE_CODE (arg0
) == NEGATE_EXPR
&& TREE_CODE (arg1
) == REAL_CST
)
6168 (swap_tree_comparison (code
), type
,
6169 TREE_OPERAND (arg0
, 0),
6170 build_real (TREE_TYPE (arg1
),
6171 REAL_VALUE_NEGATE (TREE_REAL_CST (arg1
)))));
6172 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
6173 /* a CMP (-0) -> a CMP 0 */
6174 if (TREE_CODE (arg1
) == REAL_CST
6175 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1
)))
6176 return fold (build (code
, type
, arg0
,
6177 build_real (TREE_TYPE (arg1
), dconst0
)));
6179 /* If this is a comparison of a real constant with a PLUS_EXPR
6180 or a MINUS_EXPR of a real constant, we can convert it into a
6181 comparison with a revised real constant as long as no overflow
6182 occurs when unsafe_math_optimizations are enabled. */
6183 if (flag_unsafe_math_optimizations
6184 && TREE_CODE (arg1
) == REAL_CST
6185 && (TREE_CODE (arg0
) == PLUS_EXPR
6186 || TREE_CODE (arg0
) == MINUS_EXPR
)
6187 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == REAL_CST
6188 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6189 ? MINUS_EXPR
: PLUS_EXPR
,
6190 arg1
, TREE_OPERAND (arg0
, 1), 0))
6191 && ! TREE_CONSTANT_OVERFLOW (tem
))
6192 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6195 /* Convert foo++ == CONST into ++foo == CONST + INCR.
6196 First, see if one arg is constant; find the constant arg
6197 and the other one. */
6199 tree constop
= 0, varop
= NULL_TREE
;
6200 int constopnum
= -1;
6202 if (TREE_CONSTANT (arg1
))
6203 constopnum
= 1, constop
= arg1
, varop
= arg0
;
6204 if (TREE_CONSTANT (arg0
))
6205 constopnum
= 0, constop
= arg0
, varop
= arg1
;
6207 if (constop
&& TREE_CODE (varop
) == POSTINCREMENT_EXPR
)
6209 /* This optimization is invalid for ordered comparisons
6210 if CONST+INCR overflows or if foo+incr might overflow.
6211 This optimization is invalid for floating point due to rounding.
6212 For pointer types we assume overflow doesn't happen. */
6213 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6214 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6215 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6218 = fold (build (PLUS_EXPR
, TREE_TYPE (varop
),
6219 constop
, TREE_OPERAND (varop
, 1)));
6221 /* Do not overwrite the current varop to be a preincrement,
6222 create a new node so that we won't confuse our caller who
6223 might create trees and throw them away, reusing the
6224 arguments that they passed to build. This shows up in
6225 the THEN or ELSE parts of ?: being postincrements. */
6226 varop
= build (PREINCREMENT_EXPR
, TREE_TYPE (varop
),
6227 TREE_OPERAND (varop
, 0),
6228 TREE_OPERAND (varop
, 1));
6230 /* If VAROP is a reference to a bitfield, we must mask
6231 the constant by the width of the field. */
6232 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6233 && DECL_BIT_FIELD(TREE_OPERAND
6234 (TREE_OPERAND (varop
, 0), 1)))
6237 = TREE_INT_CST_LOW (DECL_SIZE
6239 (TREE_OPERAND (varop
, 0), 1)));
6240 tree mask
, unsigned_type
;
6241 unsigned int precision
;
6242 tree folded_compare
;
6244 /* First check whether the comparison would come out
6245 always the same. If we don't do that we would
6246 change the meaning with the masking. */
6247 if (constopnum
== 0)
6248 folded_compare
= fold (build (code
, type
, constop
,
6249 TREE_OPERAND (varop
, 0)));
6251 folded_compare
= fold (build (code
, type
,
6252 TREE_OPERAND (varop
, 0),
6254 if (integer_zerop (folded_compare
)
6255 || integer_onep (folded_compare
))
6256 return omit_one_operand (type
, folded_compare
, varop
);
6258 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6259 precision
= TYPE_PRECISION (unsigned_type
);
6260 mask
= build_int_2 (~0, ~0);
6261 TREE_TYPE (mask
) = unsigned_type
;
6262 force_fit_type (mask
, 0);
6263 mask
= const_binop (RSHIFT_EXPR
, mask
,
6264 size_int (precision
- size
), 0);
6265 newconst
= fold (build (BIT_AND_EXPR
,
6266 TREE_TYPE (varop
), newconst
,
6267 convert (TREE_TYPE (varop
),
6271 t
= build (code
, type
,
6272 (constopnum
== 0) ? newconst
: varop
,
6273 (constopnum
== 1) ? newconst
: varop
);
6277 else if (constop
&& TREE_CODE (varop
) == POSTDECREMENT_EXPR
)
6279 if (POINTER_TYPE_P (TREE_TYPE (varop
))
6280 || (! FLOAT_TYPE_P (TREE_TYPE (varop
))
6281 && (code
== EQ_EXPR
|| code
== NE_EXPR
)))
6284 = fold (build (MINUS_EXPR
, TREE_TYPE (varop
),
6285 constop
, TREE_OPERAND (varop
, 1)));
6287 /* Do not overwrite the current varop to be a predecrement,
6288 create a new node so that we won't confuse our caller who
6289 might create trees and throw them away, reusing the
6290 arguments that they passed to build. This shows up in
6291 the THEN or ELSE parts of ?: being postdecrements. */
6292 varop
= build (PREDECREMENT_EXPR
, TREE_TYPE (varop
),
6293 TREE_OPERAND (varop
, 0),
6294 TREE_OPERAND (varop
, 1));
6296 if (TREE_CODE (TREE_OPERAND (varop
, 0)) == COMPONENT_REF
6297 && DECL_BIT_FIELD(TREE_OPERAND
6298 (TREE_OPERAND (varop
, 0), 1)))
6301 = TREE_INT_CST_LOW (DECL_SIZE
6303 (TREE_OPERAND (varop
, 0), 1)));
6304 tree mask
, unsigned_type
;
6305 unsigned int precision
;
6306 tree folded_compare
;
6308 if (constopnum
== 0)
6309 folded_compare
= fold (build (code
, type
, constop
,
6310 TREE_OPERAND (varop
, 0)));
6312 folded_compare
= fold (build (code
, type
,
6313 TREE_OPERAND (varop
, 0),
6315 if (integer_zerop (folded_compare
)
6316 || integer_onep (folded_compare
))
6317 return omit_one_operand (type
, folded_compare
, varop
);
6319 unsigned_type
= (*lang_hooks
.types
.type_for_size
)(size
, 1);
6320 precision
= TYPE_PRECISION (unsigned_type
);
6321 mask
= build_int_2 (~0, ~0);
6322 TREE_TYPE (mask
) = TREE_TYPE (varop
);
6323 force_fit_type (mask
, 0);
6324 mask
= const_binop (RSHIFT_EXPR
, mask
,
6325 size_int (precision
- size
), 0);
6326 newconst
= fold (build (BIT_AND_EXPR
,
6327 TREE_TYPE (varop
), newconst
,
6328 convert (TREE_TYPE (varop
),
6332 t
= build (code
, type
,
6333 (constopnum
== 0) ? newconst
: varop
,
6334 (constopnum
== 1) ? newconst
: varop
);
6340 /* Change X >= C to X > (C - 1) and X < C to X <= (C - 1) if C > 0.
6341 This transformation affects the cases which are handled in later
6342 optimizations involving comparisons with non-negative constants. */
6343 if (TREE_CODE (arg1
) == INTEGER_CST
6344 && TREE_CODE (arg0
) != INTEGER_CST
6345 && tree_int_cst_sgn (arg1
) > 0)
6351 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6352 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6357 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6358 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6366 /* Comparisons with the highest or lowest possible integer of
6367 the specified size will have known values. */
6369 int width
= GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1
)));
6371 if (TREE_CODE (arg1
) == INTEGER_CST
6372 && ! TREE_CONSTANT_OVERFLOW (arg1
)
6373 && width
<= HOST_BITS_PER_WIDE_INT
6374 && (INTEGRAL_TYPE_P (TREE_TYPE (arg1
))
6375 || POINTER_TYPE_P (TREE_TYPE (arg1
))))
6377 unsigned HOST_WIDE_INT signed_max
;
6378 unsigned HOST_WIDE_INT max
, min
;
6380 signed_max
= ((unsigned HOST_WIDE_INT
) 1 << (width
- 1)) - 1;
6382 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
6384 max
= ((unsigned HOST_WIDE_INT
) 2 << (width
- 1)) - 1;
6390 min
= ((unsigned HOST_WIDE_INT
) -1 << (width
- 1));
6393 if (TREE_INT_CST_HIGH (arg1
) == 0
6394 && TREE_INT_CST_LOW (arg1
) == max
)
6398 return omit_one_operand (type
,
6399 convert (type
, integer_zero_node
),
6403 TREE_SET_CODE (t
, EQ_EXPR
);
6406 return omit_one_operand (type
,
6407 convert (type
, integer_one_node
),
6411 TREE_SET_CODE (t
, NE_EXPR
);
6414 /* The GE_EXPR and LT_EXPR cases above are not normally
6415 reached because of previous transformations. */
6420 else if (TREE_INT_CST_HIGH (arg1
) == 0
6421 && TREE_INT_CST_LOW (arg1
) == max
- 1)
6426 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6427 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6431 arg1
= const_binop (PLUS_EXPR
, arg1
, integer_one_node
, 0);
6432 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6437 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6438 && TREE_INT_CST_LOW (arg1
) == min
)
6442 return omit_one_operand (type
,
6443 convert (type
, integer_zero_node
),
6447 TREE_SET_CODE (t
, EQ_EXPR
);
6451 return omit_one_operand (type
,
6452 convert (type
, integer_one_node
),
6456 TREE_SET_CODE (t
, NE_EXPR
);
6462 else if (TREE_INT_CST_HIGH (arg1
) == (min
? -1 : 0)
6463 && TREE_INT_CST_LOW (arg1
) == min
+ 1)
6468 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6469 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6473 arg1
= const_binop (MINUS_EXPR
, arg1
, integer_one_node
, 0);
6474 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
);
6480 else if (TREE_INT_CST_HIGH (arg1
) == 0
6481 && TREE_INT_CST_LOW (arg1
) == signed_max
6482 && TREE_UNSIGNED (TREE_TYPE (arg1
))
6483 /* signed_type does not work on pointer types. */
6484 && INTEGRAL_TYPE_P (TREE_TYPE (arg1
)))
6486 /* The following case also applies to X < signed_max+1
6487 and X >= signed_max+1 because previous transformations. */
6488 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6491 st0
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg0
));
6492 st1
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg1
));
6494 (build (code
== LE_EXPR
? GE_EXPR
: LT_EXPR
,
6495 type
, convert (st0
, arg0
),
6496 convert (st1
, integer_zero_node
)));
6502 /* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
6503 a MINUS_EXPR of a constant, we can convert it into a comparison with
6504 a revised constant as long as no overflow occurs. */
6505 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6506 && TREE_CODE (arg1
) == INTEGER_CST
6507 && (TREE_CODE (arg0
) == PLUS_EXPR
6508 || TREE_CODE (arg0
) == MINUS_EXPR
)
6509 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
6510 && 0 != (tem
= const_binop (TREE_CODE (arg0
) == PLUS_EXPR
6511 ? MINUS_EXPR
: PLUS_EXPR
,
6512 arg1
, TREE_OPERAND (arg0
, 1), 0))
6513 && ! TREE_CONSTANT_OVERFLOW (tem
))
6514 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6516 /* Similarly for a NEGATE_EXPR. */
6517 else if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6518 && TREE_CODE (arg0
) == NEGATE_EXPR
6519 && TREE_CODE (arg1
) == INTEGER_CST
6520 && 0 != (tem
= negate_expr (arg1
))
6521 && TREE_CODE (tem
) == INTEGER_CST
6522 && ! TREE_CONSTANT_OVERFLOW (tem
))
6523 return fold (build (code
, type
, TREE_OPERAND (arg0
, 0), tem
));
6525 /* If we have X - Y == 0, we can convert that to X == Y and similarly
6526 for !=. Don't do this for ordered comparisons due to overflow. */
6527 else if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6528 && integer_zerop (arg1
) && TREE_CODE (arg0
) == MINUS_EXPR
)
6529 return fold (build (code
, type
,
6530 TREE_OPERAND (arg0
, 0), TREE_OPERAND (arg0
, 1)));
6532 /* If we are widening one operand of an integer comparison,
6533 see if the other operand is similarly being widened. Perhaps we
6534 can do the comparison in the narrower type. */
6535 else if (TREE_CODE (TREE_TYPE (arg0
)) == INTEGER_TYPE
6536 && TREE_CODE (arg0
) == NOP_EXPR
6537 && (tem
= get_unwidened (arg0
, NULL_TREE
)) != arg0
6538 && (t1
= get_unwidened (arg1
, TREE_TYPE (tem
))) != 0
6539 && (TREE_TYPE (t1
) == TREE_TYPE (tem
)
6540 || (TREE_CODE (t1
) == INTEGER_CST
6541 && int_fits_type_p (t1
, TREE_TYPE (tem
)))))
6542 return fold (build (code
, type
, tem
, convert (TREE_TYPE (tem
), t1
)));
6544 /* If this is comparing a constant with a MIN_EXPR or a MAX_EXPR of a
6545 constant, we can simplify it. */
6546 else if (TREE_CODE (arg1
) == INTEGER_CST
6547 && (TREE_CODE (arg0
) == MIN_EXPR
6548 || TREE_CODE (arg0
) == MAX_EXPR
)
6549 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
)
6550 return optimize_minmax_comparison (t
);
6552 /* If we are comparing an ABS_EXPR with a constant, we can
6553 convert all the cases into explicit comparisons, but they may
6554 well not be faster than doing the ABS and one comparison.
6555 But ABS (X) <= C is a range comparison, which becomes a subtraction
6556 and a comparison, and is probably faster. */
6557 else if (code
== LE_EXPR
&& TREE_CODE (arg1
) == INTEGER_CST
6558 && TREE_CODE (arg0
) == ABS_EXPR
6559 && ! TREE_SIDE_EFFECTS (arg0
)
6560 && (0 != (tem
= negate_expr (arg1
)))
6561 && TREE_CODE (tem
) == INTEGER_CST
6562 && ! TREE_CONSTANT_OVERFLOW (tem
))
6563 return fold (build (TRUTH_ANDIF_EXPR
, type
,
6564 build (GE_EXPR
, type
, TREE_OPERAND (arg0
, 0), tem
),
6565 build (LE_EXPR
, type
,
6566 TREE_OPERAND (arg0
, 0), arg1
)));
6568 /* If this is an EQ or NE comparison with zero and ARG0 is
6569 (1 << foo) & bar, convert it to (bar >> foo) & 1. Both require
6570 two operations, but the latter can be done in one less insn
6571 on machines that have only two-operand insns or on which a
6572 constant cannot be the first operand. */
6573 if (integer_zerop (arg1
) && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6574 && TREE_CODE (arg0
) == BIT_AND_EXPR
)
6576 if (TREE_CODE (TREE_OPERAND (arg0
, 0)) == LSHIFT_EXPR
6577 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0)))
6579 fold (build (code
, type
,
6580 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6582 TREE_TYPE (TREE_OPERAND (arg0
, 0)),
6583 TREE_OPERAND (arg0
, 1),
6584 TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1)),
6585 convert (TREE_TYPE (arg0
),
6588 else if (TREE_CODE (TREE_OPERAND (arg0
, 1)) == LSHIFT_EXPR
6589 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg0
, 1), 0)))
6591 fold (build (code
, type
,
6592 build (BIT_AND_EXPR
, TREE_TYPE (arg0
),
6594 TREE_TYPE (TREE_OPERAND (arg0
, 1)),
6595 TREE_OPERAND (arg0
, 0),
6596 TREE_OPERAND (TREE_OPERAND (arg0
, 1), 1)),
6597 convert (TREE_TYPE (arg0
),
6602 /* If this is an NE or EQ comparison of zero against the result of a
6603 signed MOD operation whose second operand is a power of 2, make
6604 the MOD operation unsigned since it is simpler and equivalent. */
6605 if ((code
== NE_EXPR
|| code
== EQ_EXPR
)
6606 && integer_zerop (arg1
)
6607 && ! TREE_UNSIGNED (TREE_TYPE (arg0
))
6608 && (TREE_CODE (arg0
) == TRUNC_MOD_EXPR
6609 || TREE_CODE (arg0
) == CEIL_MOD_EXPR
6610 || TREE_CODE (arg0
) == FLOOR_MOD_EXPR
6611 || TREE_CODE (arg0
) == ROUND_MOD_EXPR
)
6612 && integer_pow2p (TREE_OPERAND (arg0
, 1)))
6614 tree newtype
= (*lang_hooks
.types
.unsigned_type
) (TREE_TYPE (arg0
));
6615 tree newmod
= build (TREE_CODE (arg0
), newtype
,
6616 convert (newtype
, TREE_OPERAND (arg0
, 0)),
6617 convert (newtype
, TREE_OPERAND (arg0
, 1)));
6619 return build (code
, type
, newmod
, convert (newtype
, arg1
));
6622 /* If this is an NE comparison of zero with an AND of one, remove the
6623 comparison since the AND will give the correct value. */
6624 if (code
== NE_EXPR
&& integer_zerop (arg1
)
6625 && TREE_CODE (arg0
) == BIT_AND_EXPR
6626 && integer_onep (TREE_OPERAND (arg0
, 1)))
6627 return convert (type
, arg0
);
6629 /* If we have (A & C) == C where C is a power of 2, convert this into
6630 (A & C) != 0. Similarly for NE_EXPR. */
6631 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6632 && TREE_CODE (arg0
) == BIT_AND_EXPR
6633 && integer_pow2p (TREE_OPERAND (arg0
, 1))
6634 && operand_equal_p (TREE_OPERAND (arg0
, 1), arg1
, 0))
6635 return fold (build (code
== EQ_EXPR
? NE_EXPR
: EQ_EXPR
, type
,
6636 arg0
, integer_zero_node
));
6638 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6639 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
6640 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6641 && TREE_CODE (arg0
) == BIT_AND_EXPR
6642 && integer_zerop (arg1
))
6644 tree arg00
= sign_bit_p (TREE_OPERAND (arg0
, 0),
6645 TREE_OPERAND (arg0
, 1));
6646 if (arg00
!= NULL_TREE
)
6648 tree stype
= (*lang_hooks
.types
.signed_type
) (TREE_TYPE (arg00
));
6649 return fold (build (code
== EQ_EXPR
? GE_EXPR
: LT_EXPR
, type
,
6650 convert (stype
, arg00
),
6651 convert (stype
, integer_zero_node
)));
6655 /* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
6656 and similarly for >= into !=. */
6657 if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6658 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6659 && TREE_CODE (arg1
) == LSHIFT_EXPR
6660 && integer_onep (TREE_OPERAND (arg1
, 0)))
6661 return build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6662 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6663 TREE_OPERAND (arg1
, 1)),
6664 convert (TREE_TYPE (arg0
), integer_zero_node
));
6666 else if ((code
== LT_EXPR
|| code
== GE_EXPR
)
6667 && TREE_UNSIGNED (TREE_TYPE (arg0
))
6668 && (TREE_CODE (arg1
) == NOP_EXPR
6669 || TREE_CODE (arg1
) == CONVERT_EXPR
)
6670 && TREE_CODE (TREE_OPERAND (arg1
, 0)) == LSHIFT_EXPR
6671 && integer_onep (TREE_OPERAND (TREE_OPERAND (arg1
, 0), 0)))
6673 build (code
== LT_EXPR
? EQ_EXPR
: NE_EXPR
, type
,
6674 convert (TREE_TYPE (arg0
),
6675 build (RSHIFT_EXPR
, TREE_TYPE (arg0
), arg0
,
6676 TREE_OPERAND (TREE_OPERAND (arg1
, 0), 1))),
6677 convert (TREE_TYPE (arg0
), integer_zero_node
));
6679 /* Simplify comparison of something with itself. (For IEEE
6680 floating-point, we can only do some of these simplifications.) */
6681 if (operand_equal_p (arg0
, arg1
, 0))
6688 if (! FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6689 return constant_boolean_node (1, type
);
6691 TREE_SET_CODE (t
, code
);
6695 /* For NE, we can only do this simplification if integer. */
6696 if (FLOAT_TYPE_P (TREE_TYPE (arg0
)))
6698 /* ... fall through ... */
6701 return constant_boolean_node (0, type
);
6707 /* If we are comparing an expression that just has comparisons
6708 of two integer values, arithmetic expressions of those comparisons,
6709 and constants, we can simplify it. There are only three cases
6710 to check: the two values can either be equal, the first can be
6711 greater, or the second can be greater. Fold the expression for
6712 those three values. Since each value must be 0 or 1, we have
6713 eight possibilities, each of which corresponds to the constant 0
6714 or 1 or one of the six possible comparisons.
6716 This handles common cases like (a > b) == 0 but also handles
6717 expressions like ((x > y) - (y > x)) > 0, which supposedly
6718 occur in macroized code. */
6720 if (TREE_CODE (arg1
) == INTEGER_CST
&& TREE_CODE (arg0
) != INTEGER_CST
)
6722 tree cval1
= 0, cval2
= 0;
6725 if (twoval_comparison_p (arg0
, &cval1
, &cval2
, &save_p
)
6726 /* Don't handle degenerate cases here; they should already
6727 have been handled anyway. */
6728 && cval1
!= 0 && cval2
!= 0
6729 && ! (TREE_CONSTANT (cval1
) && TREE_CONSTANT (cval2
))
6730 && TREE_TYPE (cval1
) == TREE_TYPE (cval2
)
6731 && INTEGRAL_TYPE_P (TREE_TYPE (cval1
))
6732 && TYPE_MAX_VALUE (TREE_TYPE (cval1
))
6733 && TYPE_MAX_VALUE (TREE_TYPE (cval2
))
6734 && ! operand_equal_p (TYPE_MIN_VALUE (TREE_TYPE (cval1
)),
6735 TYPE_MAX_VALUE (TREE_TYPE (cval2
)), 0))
6737 tree maxval
= TYPE_MAX_VALUE (TREE_TYPE (cval1
));
6738 tree minval
= TYPE_MIN_VALUE (TREE_TYPE (cval1
));
6740 /* We can't just pass T to eval_subst in case cval1 or cval2
6741 was the same as ARG1. */
6744 = fold (build (code
, type
,
6745 eval_subst (arg0
, cval1
, maxval
, cval2
, minval
),
6748 = fold (build (code
, type
,
6749 eval_subst (arg0
, cval1
, maxval
, cval2
, maxval
),
6752 = fold (build (code
, type
,
6753 eval_subst (arg0
, cval1
, minval
, cval2
, maxval
),
6756 /* All three of these results should be 0 or 1. Confirm they
6757 are. Then use those values to select the proper code
6760 if ((integer_zerop (high_result
)
6761 || integer_onep (high_result
))
6762 && (integer_zerop (equal_result
)
6763 || integer_onep (equal_result
))
6764 && (integer_zerop (low_result
)
6765 || integer_onep (low_result
)))
6767 /* Make a 3-bit mask with the high-order bit being the
6768 value for `>', the next for '=', and the low for '<'. */
6769 switch ((integer_onep (high_result
) * 4)
6770 + (integer_onep (equal_result
) * 2)
6771 + integer_onep (low_result
))
6775 return omit_one_operand (type
, integer_zero_node
, arg0
);
6796 return omit_one_operand (type
, integer_one_node
, arg0
);
6799 t
= build (code
, type
, cval1
, cval2
);
6801 return save_expr (t
);
6808 /* If this is a comparison of a field, we may be able to simplify it. */
6809 if (((TREE_CODE (arg0
) == COMPONENT_REF
6810 && (*lang_hooks
.can_use_bit_fields_p
) ())
6811 || TREE_CODE (arg0
) == BIT_FIELD_REF
)
6812 && (code
== EQ_EXPR
|| code
== NE_EXPR
)
6813 /* Handle the constant case even without -O
6814 to make sure the warnings are given. */
6815 && (optimize
|| TREE_CODE (arg1
) == INTEGER_CST
))
6817 t1
= optimize_bit_field_compare (code
, type
, arg0
, arg1
);
6821 /* If this is a comparison of complex values and either or both sides
6822 are a COMPLEX_EXPR or COMPLEX_CST, it is best to split up the
6823 comparisons and join them with a TRUTH_ANDIF_EXPR or TRUTH_ORIF_EXPR.
6824 This may prevent needless evaluations. */
6825 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6826 && TREE_CODE (TREE_TYPE (arg0
)) == COMPLEX_TYPE
6827 && (TREE_CODE (arg0
) == COMPLEX_EXPR
6828 || TREE_CODE (arg1
) == COMPLEX_EXPR
6829 || TREE_CODE (arg0
) == COMPLEX_CST
6830 || TREE_CODE (arg1
) == COMPLEX_CST
))
6832 tree subtype
= TREE_TYPE (TREE_TYPE (arg0
));
6833 tree real0
, imag0
, real1
, imag1
;
6835 arg0
= save_expr (arg0
);
6836 arg1
= save_expr (arg1
);
6837 real0
= fold (build1 (REALPART_EXPR
, subtype
, arg0
));
6838 imag0
= fold (build1 (IMAGPART_EXPR
, subtype
, arg0
));
6839 real1
= fold (build1 (REALPART_EXPR
, subtype
, arg1
));
6840 imag1
= fold (build1 (IMAGPART_EXPR
, subtype
, arg1
));
6842 return fold (build ((code
== EQ_EXPR
? TRUTH_ANDIF_EXPR
6845 fold (build (code
, type
, real0
, real1
)),
6846 fold (build (code
, type
, imag0
, imag1
))));
6849 /* Optimize comparisons of strlen vs zero to a compare of the
6850 first character of the string vs zero. To wit,
6851 strlen(ptr) == 0 => *ptr == 0
6852 strlen(ptr) != 0 => *ptr != 0
6853 Other cases should reduce to one of these two (or a constant)
6854 due to the return value of strlen being unsigned. */
6855 if ((code
== EQ_EXPR
|| code
== NE_EXPR
)
6856 && integer_zerop (arg1
)
6857 && TREE_CODE (arg0
) == CALL_EXPR
6858 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == ADDR_EXPR
)
6860 tree fndecl
= TREE_OPERAND (TREE_OPERAND (arg0
, 0), 0);
6863 if (TREE_CODE (fndecl
) == FUNCTION_DECL
6864 && DECL_BUILT_IN (fndecl
)
6865 && DECL_BUILT_IN_CLASS (fndecl
) != BUILT_IN_MD
6866 && DECL_FUNCTION_CODE (fndecl
) == BUILT_IN_STRLEN
6867 && (arglist
= TREE_OPERAND (arg0
, 1))
6868 && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist
))) == POINTER_TYPE
6869 && ! TREE_CHAIN (arglist
))
6870 return fold (build (code
, type
,
6871 build1 (INDIRECT_REF
, char_type_node
,
6872 TREE_VALUE(arglist
)),
6873 integer_zero_node
));
6876 /* From here on, the only cases we handle are when the result is
6877 known to be a constant.
6879 To compute GT, swap the arguments and do LT.
6880 To compute GE, do LT and invert the result.
6881 To compute LE, swap the arguments, do LT and invert the result.
6882 To compute NE, do EQ and invert the result.
6884 Therefore, the code below must handle only EQ and LT. */
6886 if (code
== LE_EXPR
|| code
== GT_EXPR
)
6888 tem
= arg0
, arg0
= arg1
, arg1
= tem
;
6889 code
= swap_tree_comparison (code
);
6892 /* Note that it is safe to invert for real values here because we
6893 will check below in the one case that it matters. */
6897 if (code
== NE_EXPR
|| code
== GE_EXPR
)
6900 code
= invert_tree_comparison (code
);
6903 /* Compute a result for LT or EQ if args permit;
6904 otherwise return T. */
6905 if (TREE_CODE (arg0
) == INTEGER_CST
&& TREE_CODE (arg1
) == INTEGER_CST
)
6907 if (code
== EQ_EXPR
)
6908 t1
= build_int_2 (tree_int_cst_equal (arg0
, arg1
), 0);
6910 t1
= build_int_2 ((TREE_UNSIGNED (TREE_TYPE (arg0
))
6911 ? INT_CST_LT_UNSIGNED (arg0
, arg1
)
6912 : INT_CST_LT (arg0
, arg1
)),
6916 #if 0 /* This is no longer useful, but breaks some real code. */
6917 /* Assume a nonexplicit constant cannot equal an explicit one,
6918 since such code would be undefined anyway.
6919 Exception: on sysvr4, using #pragma weak,
6920 a label can come out as 0. */
6921 else if (TREE_CODE (arg1
) == INTEGER_CST
6922 && !integer_zerop (arg1
)
6923 && TREE_CONSTANT (arg0
)
6924 && TREE_CODE (arg0
) == ADDR_EXPR
6926 t1
= build_int_2 (0, 0);
6928 /* Two real constants can be compared explicitly. */
6929 else if (TREE_CODE (arg0
) == REAL_CST
&& TREE_CODE (arg1
) == REAL_CST
)
6931 /* If either operand is a NaN, the result is false with two
6932 exceptions: First, an NE_EXPR is true on NaNs, but that case
6933 is already handled correctly since we will be inverting the
6934 result for NE_EXPR. Second, if we had inverted a LE_EXPR
6935 or a GE_EXPR into a LT_EXPR, we must return true so that it
6936 will be inverted into false. */
6938 if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg0
))
6939 || REAL_VALUE_ISNAN (TREE_REAL_CST (arg1
)))
6940 t1
= build_int_2 (invert
&& code
== LT_EXPR
, 0);
6942 else if (code
== EQ_EXPR
)
6943 t1
= build_int_2 (REAL_VALUES_EQUAL (TREE_REAL_CST (arg0
),
6944 TREE_REAL_CST (arg1
)),
6947 t1
= build_int_2 (REAL_VALUES_LESS (TREE_REAL_CST (arg0
),
6948 TREE_REAL_CST (arg1
)),
6952 if (t1
== NULL_TREE
)
6956 TREE_INT_CST_LOW (t1
) ^= 1;
6958 TREE_TYPE (t1
) = type
;
6959 if (TREE_CODE (type
) == BOOLEAN_TYPE
)
6960 return (*lang_hooks
.truthvalue_conversion
) (t1
);
6964 /* Pedantic ANSI C says that a conditional expression is never an lvalue,
6965 so all simple results must be passed through pedantic_non_lvalue. */
6966 if (TREE_CODE (arg0
) == INTEGER_CST
)
6967 return pedantic_non_lvalue
6968 (TREE_OPERAND (t
, (integer_zerop (arg0
) ? 2 : 1)));
6969 else if (operand_equal_p (arg1
, TREE_OPERAND (expr
, 2), 0))
6970 return pedantic_omit_one_operand (type
, arg1
, arg0
);
6972 /* If the second operand is zero, invert the comparison and swap
6973 the second and third operands. Likewise if the second operand
6974 is constant and the third is not or if the third operand is
6975 equivalent to the first operand of the comparison. */
6977 if (integer_zerop (arg1
)
6978 || (TREE_CONSTANT (arg1
) && ! TREE_CONSTANT (TREE_OPERAND (t
, 2)))
6979 || (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
6980 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
6981 TREE_OPERAND (t
, 2),
6982 TREE_OPERAND (arg0
, 1))))
6984 /* See if this can be inverted. If it can't, possibly because
6985 it was a floating-point inequality comparison, don't do
6987 tem
= invert_truthvalue (arg0
);
6989 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
6991 t
= build (code
, type
, tem
,
6992 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
6994 /* arg1 should be the first argument of the new T. */
6995 arg1
= TREE_OPERAND (t
, 1);
7000 /* If we have A op B ? A : C, we may be able to convert this to a
7001 simpler expression, depending on the operation and the values
7002 of B and C. Signed zeros prevent all of these transformations,
7003 for reasons given above each one. */
7005 if (TREE_CODE_CLASS (TREE_CODE (arg0
)) == '<'
7006 && operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 0),
7007 arg1
, TREE_OPERAND (arg0
, 1))
7008 && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1
))))
7010 tree arg2
= TREE_OPERAND (t
, 2);
7011 enum tree_code comp_code
= TREE_CODE (arg0
);
7015 /* If we have A op 0 ? A : -A, consider applying the following
7018 A == 0? A : -A same as -A
7019 A != 0? A : -A same as A
7020 A >= 0? A : -A same as abs (A)
7021 A > 0? A : -A same as abs (A)
7022 A <= 0? A : -A same as -abs (A)
7023 A < 0? A : -A same as -abs (A)
7025 None of these transformations work for modes with signed
7026 zeros. If A is +/-0, the first two transformations will
7027 change the sign of the result (from +0 to -0, or vice
7028 versa). The last four will fix the sign of the result,
7029 even though the original expressions could be positive or
7030 negative, depending on the sign of A.
7032 Note that all these transformations are correct if A is
7033 NaN, since the two alternatives (A and -A) are also NaNs. */
7034 if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0
, 1)))
7035 ? real_zerop (TREE_OPERAND (arg0
, 1))
7036 : integer_zerop (TREE_OPERAND (arg0
, 1)))
7037 && TREE_CODE (arg2
) == NEGATE_EXPR
7038 && operand_equal_p (TREE_OPERAND (arg2
, 0), arg1
, 0))
7046 (convert (TREE_TYPE (TREE_OPERAND (t
, 1)),
7049 return pedantic_non_lvalue (convert (type
, arg1
));
7052 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7053 arg1
= convert ((*lang_hooks
.types
.signed_type
)
7054 (TREE_TYPE (arg1
)), arg1
);
7055 return pedantic_non_lvalue
7056 (convert (type
, fold (build1 (ABS_EXPR
,
7057 TREE_TYPE (arg1
), arg1
))));
7060 if (TREE_UNSIGNED (TREE_TYPE (arg1
)))
7061 arg1
= convert ((lang_hooks
.types
.signed_type
)
7062 (TREE_TYPE (arg1
)), arg1
);
7063 return pedantic_non_lvalue
7064 (negate_expr (convert (type
,
7065 fold (build1 (ABS_EXPR
,
7072 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
7073 A == 0 ? A : 0 is always 0 unless A is -0. Note that
7074 both transformations are correct when A is NaN: A != 0
7075 is then true, and A == 0 is false. */
7077 if (integer_zerop (TREE_OPERAND (arg0
, 1)) && integer_zerop (arg2
))
7079 if (comp_code
== NE_EXPR
)
7080 return pedantic_non_lvalue (convert (type
, arg1
));
7081 else if (comp_code
== EQ_EXPR
)
7082 return pedantic_non_lvalue (convert (type
, integer_zero_node
));
7085 /* Try some transformations of A op B ? A : B.
7087 A == B? A : B same as B
7088 A != B? A : B same as A
7089 A >= B? A : B same as max (A, B)
7090 A > B? A : B same as max (B, A)
7091 A <= B? A : B same as min (A, B)
7092 A < B? A : B same as min (B, A)
7094 As above, these transformations don't work in the presence
7095 of signed zeros. For example, if A and B are zeros of
7096 opposite sign, the first two transformations will change
7097 the sign of the result. In the last four, the original
7098 expressions give different results for (A=+0, B=-0) and
7099 (A=-0, B=+0), but the transformed expressions do not.
7101 The first two transformations are correct if either A or B
7102 is a NaN. In the first transformation, the condition will
7103 be false, and B will indeed be chosen. In the case of the
7104 second transformation, the condition A != B will be true,
7105 and A will be chosen.
7107 The conversions to max() and min() are not correct if B is
7108 a number and A is not. The conditions in the original
7109 expressions will be false, so all four give B. The min()
7110 and max() versions would give a NaN instead. */
7111 if (operand_equal_for_comparison_p (TREE_OPERAND (arg0
, 1),
7112 arg2
, TREE_OPERAND (arg0
, 0)))
7114 tree comp_op0
= TREE_OPERAND (arg0
, 0);
7115 tree comp_op1
= TREE_OPERAND (arg0
, 1);
7116 tree comp_type
= TREE_TYPE (comp_op0
);
7118 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
7119 if (TYPE_MAIN_VARIANT (comp_type
) == TYPE_MAIN_VARIANT (type
))
7129 return pedantic_non_lvalue (convert (type
, arg2
));
7131 return pedantic_non_lvalue (convert (type
, arg1
));
7134 /* In C++ a ?: expression can be an lvalue, so put the
7135 operand which will be used if they are equal first
7136 so that we can convert this back to the
7137 corresponding COND_EXPR. */
7138 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7139 return pedantic_non_lvalue
7140 (convert (type
, fold (build (MIN_EXPR
, comp_type
,
7141 (comp_code
== LE_EXPR
7142 ? comp_op0
: comp_op1
),
7143 (comp_code
== LE_EXPR
7144 ? comp_op1
: comp_op0
)))));
7148 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1
))))
7149 return pedantic_non_lvalue
7150 (convert (type
, fold (build (MAX_EXPR
, comp_type
,
7151 (comp_code
== GE_EXPR
7152 ? comp_op0
: comp_op1
),
7153 (comp_code
== GE_EXPR
7154 ? comp_op1
: comp_op0
)))));
7161 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
7162 we might still be able to simplify this. For example,
7163 if C1 is one less or one more than C2, this might have started
7164 out as a MIN or MAX and been transformed by this function.
7165 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
7167 if (INTEGRAL_TYPE_P (type
)
7168 && TREE_CODE (TREE_OPERAND (arg0
, 1)) == INTEGER_CST
7169 && TREE_CODE (arg2
) == INTEGER_CST
)
7173 /* We can replace A with C1 in this case. */
7174 arg1
= convert (type
, TREE_OPERAND (arg0
, 1));
7175 t
= build (code
, type
, TREE_OPERAND (t
, 0), arg1
,
7176 TREE_OPERAND (t
, 2));
7180 /* If C1 is C2 + 1, this is min(A, C2). */
7181 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7182 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7183 const_binop (PLUS_EXPR
, arg2
,
7184 integer_one_node
, 0), 1))
7185 return pedantic_non_lvalue
7186 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7190 /* If C1 is C2 - 1, this is min(A, C2). */
7191 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7192 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7193 const_binop (MINUS_EXPR
, arg2
,
7194 integer_one_node
, 0), 1))
7195 return pedantic_non_lvalue
7196 (fold (build (MIN_EXPR
, type
, arg1
, arg2
)));
7200 /* If C1 is C2 - 1, this is max(A, C2). */
7201 if (! operand_equal_p (arg2
, TYPE_MIN_VALUE (type
), 1)
7202 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7203 const_binop (MINUS_EXPR
, arg2
,
7204 integer_one_node
, 0), 1))
7205 return pedantic_non_lvalue
7206 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7210 /* If C1 is C2 + 1, this is max(A, C2). */
7211 if (! operand_equal_p (arg2
, TYPE_MAX_VALUE (type
), 1)
7212 && operand_equal_p (TREE_OPERAND (arg0
, 1),
7213 const_binop (PLUS_EXPR
, arg2
,
7214 integer_one_node
, 0), 1))
7215 return pedantic_non_lvalue
7216 (fold (build (MAX_EXPR
, type
, arg1
, arg2
)));
7225 /* If the second operand is simpler than the third, swap them
7226 since that produces better jump optimization results. */
7227 if ((TREE_CONSTANT (arg1
) || DECL_P (arg1
)
7228 || TREE_CODE (arg1
) == SAVE_EXPR
)
7229 && ! (TREE_CONSTANT (TREE_OPERAND (t
, 2))
7230 || DECL_P (TREE_OPERAND (t
, 2))
7231 || TREE_CODE (TREE_OPERAND (t
, 2)) == SAVE_EXPR
))
7233 /* See if this can be inverted. If it can't, possibly because
7234 it was a floating-point inequality comparison, don't do
7236 tem
= invert_truthvalue (arg0
);
7238 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7240 t
= build (code
, type
, tem
,
7241 TREE_OPERAND (t
, 2), TREE_OPERAND (t
, 1));
7243 /* arg1 should be the first argument of the new T. */
7244 arg1
= TREE_OPERAND (t
, 1);
7249 /* Convert A ? 1 : 0 to simply A. */
7250 if (integer_onep (TREE_OPERAND (t
, 1))
7251 && integer_zerop (TREE_OPERAND (t
, 2))
7252 /* If we try to convert TREE_OPERAND (t, 0) to our type, the
7253 call to fold will try to move the conversion inside
7254 a COND, which will recurse. In that case, the COND_EXPR
7255 is probably the best choice, so leave it alone. */
7256 && type
== TREE_TYPE (arg0
))
7257 return pedantic_non_lvalue (arg0
);
7259 /* Convert A ? 0 : 1 to !A. This prefers the use of NOT_EXPR
7260 over COND_EXPR in cases such as floating point comparisons. */
7261 if (integer_zerop (TREE_OPERAND (t
, 1))
7262 && integer_onep (TREE_OPERAND (t
, 2))
7263 && truth_value_p (TREE_CODE (arg0
)))
7264 return pedantic_non_lvalue (convert (type
,
7265 invert_truthvalue (arg0
)));
7267 /* Look for expressions of the form A & 2 ? 2 : 0. The result of this
7268 operation is simply A & 2. */
7270 if (integer_zerop (TREE_OPERAND (t
, 2))
7271 && TREE_CODE (arg0
) == NE_EXPR
7272 && integer_zerop (TREE_OPERAND (arg0
, 1))
7273 && integer_pow2p (arg1
)
7274 && TREE_CODE (TREE_OPERAND (arg0
, 0)) == BIT_AND_EXPR
7275 && operand_equal_p (TREE_OPERAND (TREE_OPERAND (arg0
, 0), 1),
7277 return pedantic_non_lvalue (convert (type
, TREE_OPERAND (arg0
, 0)));
7279 /* Convert A ? B : 0 into A && B if A and B are truth values. */
7280 if (integer_zerop (TREE_OPERAND (t
, 2))
7281 && truth_value_p (TREE_CODE (arg0
))
7282 && truth_value_p (TREE_CODE (arg1
)))
7283 return pedantic_non_lvalue (fold (build (TRUTH_ANDIF_EXPR
, type
,
7286 /* Convert A ? B : 1 into !A || B if A and B are truth values. */
7287 if (integer_onep (TREE_OPERAND (t
, 2))
7288 && truth_value_p (TREE_CODE (arg0
))
7289 && truth_value_p (TREE_CODE (arg1
)))
7291 /* Only perform transformation if ARG0 is easily inverted. */
7292 tem
= invert_truthvalue (arg0
);
7293 if (TREE_CODE (tem
) != TRUTH_NOT_EXPR
)
7294 return pedantic_non_lvalue (fold (build (TRUTH_ORIF_EXPR
, type
,
7301 /* When pedantic, a compound expression can be neither an lvalue
7302 nor an integer constant expression. */
7303 if (TREE_SIDE_EFFECTS (arg0
) || pedantic
)
7305 /* Don't let (0, 0) be null pointer constant. */
7306 if (integer_zerop (arg1
))
7307 return build1 (NOP_EXPR
, type
, arg1
);
7308 return convert (type
, arg1
);
7312 return build_complex (type
, arg0
, arg1
);
7316 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7318 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7319 return omit_one_operand (type
, TREE_OPERAND (arg0
, 0),
7320 TREE_OPERAND (arg0
, 1));
7321 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7322 return TREE_REALPART (arg0
);
7323 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7324 return fold (build (TREE_CODE (arg0
), type
,
7325 fold (build1 (REALPART_EXPR
, type
,
7326 TREE_OPERAND (arg0
, 0))),
7327 fold (build1 (REALPART_EXPR
,
7328 type
, TREE_OPERAND (arg0
, 1)))));
7332 if (TREE_CODE (TREE_TYPE (arg0
)) != COMPLEX_TYPE
)
7333 return convert (type
, integer_zero_node
);
7334 else if (TREE_CODE (arg0
) == COMPLEX_EXPR
)
7335 return omit_one_operand (type
, TREE_OPERAND (arg0
, 1),
7336 TREE_OPERAND (arg0
, 0));
7337 else if (TREE_CODE (arg0
) == COMPLEX_CST
)
7338 return TREE_IMAGPART (arg0
);
7339 else if (TREE_CODE (arg0
) == PLUS_EXPR
|| TREE_CODE (arg0
) == MINUS_EXPR
)
7340 return fold (build (TREE_CODE (arg0
), type
,
7341 fold (build1 (IMAGPART_EXPR
, type
,
7342 TREE_OPERAND (arg0
, 0))),
7343 fold (build1 (IMAGPART_EXPR
, type
,
7344 TREE_OPERAND (arg0
, 1)))));
7347 /* Pull arithmetic ops out of the CLEANUP_POINT_EXPR where
7349 case CLEANUP_POINT_EXPR
:
7350 if (! has_cleanups (arg0
))
7351 return TREE_OPERAND (t
, 0);
7354 enum tree_code code0
= TREE_CODE (arg0
);
7355 int kind0
= TREE_CODE_CLASS (code0
);
7356 tree arg00
= TREE_OPERAND (arg0
, 0);
7359 if (kind0
== '1' || code0
== TRUTH_NOT_EXPR
)
7360 return fold (build1 (code0
, type
,
7361 fold (build1 (CLEANUP_POINT_EXPR
,
7362 TREE_TYPE (arg00
), arg00
))));
7364 if (kind0
== '<' || kind0
== '2'
7365 || code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
7366 || code0
== TRUTH_AND_EXPR
|| code0
== TRUTH_OR_EXPR
7367 || code0
== TRUTH_XOR_EXPR
)
7369 arg01
= TREE_OPERAND (arg0
, 1);
7371 if (TREE_CONSTANT (arg00
)
7372 || ((code0
== TRUTH_ANDIF_EXPR
|| code0
== TRUTH_ORIF_EXPR
)
7373 && ! has_cleanups (arg00
)))
7374 return fold (build (code0
, type
, arg00
,
7375 fold (build1 (CLEANUP_POINT_EXPR
,
7376 TREE_TYPE (arg01
), arg01
))));
7378 if (TREE_CONSTANT (arg01
))
7379 return fold (build (code0
, type
,
7380 fold (build1 (CLEANUP_POINT_EXPR
,
7381 TREE_TYPE (arg00
), arg00
)),
7389 /* Check for a built-in function. */
7390 if (TREE_CODE (TREE_OPERAND (expr
, 0)) == ADDR_EXPR
7391 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0))
7393 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (expr
, 0), 0)))
7395 tree tmp
= fold_builtin (expr
);
7403 } /* switch (code) */
7406 /* Determine if first argument is a multiple of second argument. Return 0 if
7407 it is not, or we cannot easily determined it to be.
7409 An example of the sort of thing we care about (at this point; this routine
7410 could surely be made more general, and expanded to do what the *_DIV_EXPR's
7411 fold cases do now) is discovering that
7413 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7419 when we know that the two SAVE_EXPR (J * 8) nodes are the same node.
7421 This code also handles discovering that
7423 SAVE_EXPR (I) * SAVE_EXPR (J * 8)
7425 is a multiple of 8 so we don't have to worry about dealing with a
7428 Note that we *look* inside a SAVE_EXPR only to determine how it was
7429 calculated; it is not safe for fold to do much of anything else with the
7430 internals of a SAVE_EXPR, since it cannot know when it will be evaluated
7431 at run time. For example, the latter example above *cannot* be implemented
7432 as SAVE_EXPR (I) * J or any variant thereof, since the value of J at
7433 evaluation time of the original SAVE_EXPR is not necessarily the same at
7434 the time the new expression is evaluated. The only optimization of this
7435 sort that would be valid is changing
7437 SAVE_EXPR (I) * SAVE_EXPR (SAVE_EXPR (J) * 8)
7441 SAVE_EXPR (I) * SAVE_EXPR (J)
7443 (where the same SAVE_EXPR (J) is used in the original and the
7444 transformed version). */
7447 multiple_of_p (type
, top
, bottom
)
7452 if (operand_equal_p (top
, bottom
, 0))
7455 if (TREE_CODE (type
) != INTEGER_TYPE
)
7458 switch (TREE_CODE (top
))
7461 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7462 || multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7466 return (multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
)
7467 && multiple_of_p (type
, TREE_OPERAND (top
, 1), bottom
));
7470 if (TREE_CODE (TREE_OPERAND (top
, 1)) == INTEGER_CST
)
7474 op1
= TREE_OPERAND (top
, 1);
7475 /* const_binop may not detect overflow correctly,
7476 so check for it explicitly here. */
7477 if (TYPE_PRECISION (TREE_TYPE (size_one_node
))
7478 > TREE_INT_CST_LOW (op1
)
7479 && TREE_INT_CST_HIGH (op1
) == 0
7480 && 0 != (t1
= convert (type
,
7481 const_binop (LSHIFT_EXPR
, size_one_node
,
7483 && ! TREE_OVERFLOW (t1
))
7484 return multiple_of_p (type
, t1
, bottom
);
7489 /* Can't handle conversions from non-integral or wider integral type. */
7490 if ((TREE_CODE (TREE_TYPE (TREE_OPERAND (top
, 0))) != INTEGER_TYPE
)
7491 || (TYPE_PRECISION (type
)
7492 < TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (top
, 0)))))
7495 /* .. fall through ... */
7498 return multiple_of_p (type
, TREE_OPERAND (top
, 0), bottom
);
7501 if (TREE_CODE (bottom
) != INTEGER_CST
7502 || (TREE_UNSIGNED (type
)
7503 && (tree_int_cst_sgn (top
) < 0
7504 || tree_int_cst_sgn (bottom
) < 0)))
7506 return integer_zerop (const_binop (TRUNC_MOD_EXPR
,
7514 /* Return true if `t' is known to be non-negative. */
7517 tree_expr_nonnegative_p (t
)
7520 switch (TREE_CODE (t
))
7530 /* These are undefined at zero. This is true even if
7531 C[LT]Z_DEFINED_VALUE_AT_ZERO is set, since what we're
7532 computing here is a user-visible property. */
7536 return tree_int_cst_sgn (t
) >= 0;
7537 case TRUNC_DIV_EXPR
:
7539 case FLOOR_DIV_EXPR
:
7540 case ROUND_DIV_EXPR
:
7541 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7542 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7543 case TRUNC_MOD_EXPR
:
7545 case FLOOR_MOD_EXPR
:
7546 case ROUND_MOD_EXPR
:
7547 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7549 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1))
7550 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 2));
7552 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7554 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7555 && tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7557 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0))
7558 || tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7560 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7562 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 1));
7564 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7565 case NON_LVALUE_EXPR
:
7566 return tree_expr_nonnegative_p (TREE_OPERAND (t
, 0));
7568 return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t
));
7571 if (truth_value_p (TREE_CODE (t
)))
7572 /* Truth values evaluate to 0 or 1, which is nonnegative. */
7575 /* We don't know sign of `t', so be conservative and return false. */
7580 /* Return true if `r' is known to be non-negative.
7581 Only handles constants at the moment. */
7584 rtl_expr_nonnegative_p (r
)
7587 switch (GET_CODE (r
))
7590 return INTVAL (r
) >= 0;
7593 if (GET_MODE (r
) == VOIDmode
)
7594 return CONST_DOUBLE_HIGH (r
) >= 0;
7602 units
= CONST_VECTOR_NUNITS (r
);
7604 for (i
= 0; i
< units
; ++i
)
7606 elt
= CONST_VECTOR_ELT (r
, i
);
7607 if (!rtl_expr_nonnegative_p (elt
))
7616 /* These are always nonnegative. */
7624 #include "gt-fold-const.h"