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2006-09-07 Eric Christopher <echristo@apple.com>
[thirdparty/gcc.git] / gcc / fold-const.c
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2bc77e10 1/* Fold a constant sub-tree into a single node for C-compiler
22331643 2 Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
63bf54cf 3 2000, 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
2bc77e10 4
f12b58b3 5This file is part of GCC.
2bc77e10 6
f12b58b3 7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
2bc77e10 11
f12b58b3 12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
2bc77e10 16
17You should have received a copy of the GNU General Public License
f12b58b3 18along with GCC; see the file COPYING. If not, write to the Free
67ce556b 19Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
2002110-1301, USA. */
2bc77e10 21
4bbea254 22/*@@ This file should be rewritten to use an arbitrary precision
2bc77e10 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. */
29
30384dcf 30/* The entry points in this file are fold, size_int_wide, size_binop
6e44befc 31 and force_fit_type.
2bc77e10 32
33 fold takes a tree as argument and returns a simplified tree.
34
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'.
38
39 size_int takes an integer value, and creates a tree constant
6e44befc 40 with type from `sizetype'.
41
4d28c5d1 42 force_fit_type takes a constant, an overflowable flag and prior
43 overflow indicators. It forces the value to fit the type and sets
44 TREE_OVERFLOW and TREE_CONSTANT_OVERFLOW as appropriate. */
6e44befc 45
0dbd1c74 46#include "config.h"
5ee8fe30 47#include "system.h"
805e22b2 48#include "coretypes.h"
49#include "tm.h"
2bc77e10 50#include "flags.h"
51#include "tree.h"
ef258422 52#include "real.h"
0f9685e4 53#include "rtl.h"
aed0bd19 54#include "expr.h"
7953c610 55#include "tm_p.h"
12874aaf 56#include "toplev.h"
1bfd55c5 57#include "ggc.h"
15d769aa 58#include "hashtab.h"
20325f61 59#include "langhooks.h"
fc3df357 60#include "md5.h"
2bc77e10 61
47be647d 62/* Non-zero if we are folding constants inside an initializer; zero
63 otherwise. */
64int folding_initializer = 0;
65
318a728f 66/* The following constants represent a bit based encoding of GCC's
67 comparison operators. This encoding simplifies transformations
68 on relational comparison operators, such as AND and OR. */
69enum comparison_code {
70 COMPCODE_FALSE = 0,
71 COMPCODE_LT = 1,
72 COMPCODE_EQ = 2,
73 COMPCODE_LE = 3,
74 COMPCODE_GT = 4,
75 COMPCODE_LTGT = 5,
76 COMPCODE_GE = 6,
77 COMPCODE_ORD = 7,
78 COMPCODE_UNORD = 8,
79 COMPCODE_UNLT = 9,
80 COMPCODE_UNEQ = 10,
81 COMPCODE_UNLE = 11,
82 COMPCODE_UNGT = 12,
83 COMPCODE_NE = 13,
84 COMPCODE_UNGE = 14,
85 COMPCODE_TRUE = 15
86};
87
de1b648b 88static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
89static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
bd214d13 90static bool negate_mathfn_p (enum built_in_function);
de1b648b 91static bool negate_expr_p (tree);
92static tree negate_expr (tree);
93static tree split_tree (tree, enum tree_code, tree *, tree *, tree *, int);
94static tree associate_trees (tree, tree, enum tree_code, tree);
de1b648b 95static tree const_binop (enum tree_code, tree, tree, int);
318a728f 96static enum comparison_code comparison_to_compcode (enum tree_code);
97static enum tree_code compcode_to_comparison (enum comparison_code);
98static tree combine_comparisons (enum tree_code, enum tree_code,
99 enum tree_code, tree, tree, tree);
de1b648b 100static int truth_value_p (enum tree_code);
101static int operand_equal_for_comparison_p (tree, tree, tree);
102static int twoval_comparison_p (tree, tree *, tree *, int *);
103static tree eval_subst (tree, tree, tree, tree, tree);
104static tree pedantic_omit_one_operand (tree, tree, tree);
105static tree distribute_bit_expr (enum tree_code, tree, tree, tree);
106static tree make_bit_field_ref (tree, tree, int, int, int);
107static tree optimize_bit_field_compare (enum tree_code, tree, tree, tree);
108static tree decode_field_reference (tree, HOST_WIDE_INT *, HOST_WIDE_INT *,
109 enum machine_mode *, int *, int *,
110 tree *, tree *);
111static int all_ones_mask_p (tree, int);
112static tree sign_bit_p (tree, tree);
113static int simple_operand_p (tree);
114static tree range_binop (enum tree_code, tree, tree, int, tree, int);
66108e20 115static tree range_predecessor (tree);
116static tree range_successor (tree);
de1b648b 117static tree make_range (tree, int *, tree *, tree *);
118static tree build_range_check (tree, tree, int, tree, tree);
119static int merge_ranges (int *, tree *, tree *, int, tree, tree, int, tree,
120 tree);
2c17ebb2 121static tree fold_range_test (enum tree_code, tree, tree, tree);
9b1fa4a0 122static tree fold_cond_expr_with_comparison (tree, tree, tree, tree);
de1b648b 123static tree unextend (tree, int, int, tree);
124static tree fold_truthop (enum tree_code, tree, tree, tree);
155acab4 125static tree optimize_minmax_comparison (enum tree_code, tree, tree, tree);
de1b648b 126static tree extract_muldiv (tree, tree, enum tree_code, tree);
127static tree extract_muldiv_1 (tree, tree, enum tree_code, tree);
de1b648b 128static int multiple_of_p (tree, tree, tree);
1ebe9a83 129static tree fold_binary_op_with_conditional_arg (enum tree_code, tree,
130 tree, tree,
5fe1fe72 131 tree, tree, int);
de1b648b 132static bool fold_real_zero_addition_p (tree, tree, int);
133static tree fold_mathfn_compare (enum built_in_function, enum tree_code,
134 tree, tree, tree);
135static tree fold_inf_compare (enum tree_code, tree, tree, tree);
270029e0 136static tree fold_div_compare (enum tree_code, tree, tree, tree);
bd214d13 137static bool reorder_operands_p (tree, tree);
9d77437d 138static tree fold_negate_const (tree, tree);
c183306c 139static tree fold_not_const (tree, tree);
ad46984d 140static tree fold_relational_const (enum tree_code, tree, tree, tree);
5f4092ed 141static int native_encode_expr (tree, unsigned char *, int);
142static tree native_interpret_expr (tree, unsigned char *, int);
143
9d77437d 144
083a2b5e 145/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
146 overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
147 and SUM1. Then this yields nonzero if overflow occurred during the
148 addition.
149
150 Overflow occurs if A and B have the same sign, but A and SUM differ in
151 sign. Use `^' to test whether signs differ, and `< 0' to isolate the
152 sign. */
153#define OVERFLOW_SUM_SIGN(a, b, sum) ((~((a) ^ (b)) & ((a) ^ (sum))) < 0)
2bc77e10 154\f
b572011e 155/* To do constant folding on INTEGER_CST nodes requires two-word arithmetic.
bd5b3bce 156 We do that by representing the two-word integer in 4 words, with only
083a2b5e 157 HOST_BITS_PER_WIDE_INT / 2 bits stored in each word, as a positive
158 number. The value of the word is LOWPART + HIGHPART * BASE. */
bd5b3bce 159
160#define LOWPART(x) \
083a2b5e 161 ((x) & (((unsigned HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2)) - 1))
bd5b3bce 162#define HIGHPART(x) \
083a2b5e 163 ((unsigned HOST_WIDE_INT) (x) >> HOST_BITS_PER_WIDE_INT / 2)
164#define BASE ((unsigned HOST_WIDE_INT) 1 << HOST_BITS_PER_WIDE_INT / 2)
2bc77e10 165
bd5b3bce 166/* Unpack a two-word integer into 4 words.
b572011e 167 LOW and HI are the integer, as two `HOST_WIDE_INT' pieces.
bd5b3bce 168 WORDS points to the array of HOST_WIDE_INTs. */
2bc77e10 169
170static void
de1b648b 171encode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT low, HOST_WIDE_INT hi)
2bc77e10 172{
bd5b3bce 173 words[0] = LOWPART (low);
174 words[1] = HIGHPART (low);
175 words[2] = LOWPART (hi);
176 words[3] = HIGHPART (hi);
2bc77e10 177}
178
bd5b3bce 179/* Pack an array of 4 words into a two-word integer.
180 WORDS points to the array of words.
b572011e 181 The integer is stored into *LOW and *HI as two `HOST_WIDE_INT' pieces. */
2bc77e10 182
183static void
dc81944a 184decode (HOST_WIDE_INT *words, unsigned HOST_WIDE_INT *low,
185 HOST_WIDE_INT *hi)
2bc77e10 186{
083a2b5e 187 *low = words[0] + words[1] * BASE;
188 *hi = words[2] + words[3] * BASE;
2bc77e10 189}
190\f
4d28c5d1 191/* T is an INT_CST node. OVERFLOWABLE indicates if we are interested
192 in overflow of the value, when >0 we are only interested in signed
193 overflow, for <0 we are interested in any overflow. OVERFLOWED
194 indicates whether overflow has already occurred. CONST_OVERFLOWED
195 indicates whether constant overflow has already occurred. We force
196 T's value to be within range of T's type (by setting to 0 or 1 all
197 the bits outside the type's range). We set TREE_OVERFLOWED if,
9ee236f3 198 OVERFLOWED is nonzero,
4d28c5d1 199 or OVERFLOWABLE is >0 and signed overflow occurs
200 or OVERFLOWABLE is <0 and any overflow occurs
201 We set TREE_CONSTANT_OVERFLOWED if,
9ee236f3 202 CONST_OVERFLOWED is nonzero
4d28c5d1 203 or we set TREE_OVERFLOWED.
204 We return either the original T, or a copy. */
083a2b5e 205
4d28c5d1 206tree
7c446c95 207force_fit_type (tree t, int overflowable,
208 bool overflowed, bool overflowed_const)
2bc77e10 209{
a0c2c45b 210 unsigned HOST_WIDE_INT low;
211 HOST_WIDE_INT high;
212 unsigned int prec;
4d28c5d1 213 int sign_extended_type;
2bc77e10 214
fdada98f 215 gcc_assert (TREE_CODE (t) == INTEGER_CST);
0c5713a2 216
817e5691 217 low = TREE_INT_CST_LOW (t);
218 high = TREE_INT_CST_HIGH (t);
d7b6c802 219
1bc16cab 220 if (POINTER_TYPE_P (TREE_TYPE (t))
221 || TREE_CODE (TREE_TYPE (t)) == OFFSET_TYPE)
2bc77e10 222 prec = POINTER_SIZE;
817e5691 223 else
224 prec = TYPE_PRECISION (TREE_TYPE (t));
4d28c5d1 225 /* Size types *are* sign extended. */
226 sign_extended_type = (!TYPE_UNSIGNED (TREE_TYPE (t))
227 || (TREE_CODE (TREE_TYPE (t)) == INTEGER_TYPE
228 && TYPE_IS_SIZETYPE (TREE_TYPE (t))));
2bc77e10 229
230 /* First clear all bits that are beyond the type's precision. */
231
b38d56be 232 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
2bc77e10 233 ;
b572011e 234 else if (prec > HOST_BITS_PER_WIDE_INT)
4d28c5d1 235 high &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
2bc77e10 236 else
237 {
4d28c5d1 238 high = 0;
b572011e 239 if (prec < HOST_BITS_PER_WIDE_INT)
4d28c5d1 240 low &= ~((HOST_WIDE_INT) (-1) << prec);
241 }
242
243 if (!sign_extended_type)
244 /* No sign extension */;
b38d56be 245 else if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
4d28c5d1 246 /* Correct width already. */;
247 else if (prec > HOST_BITS_PER_WIDE_INT)
248 {
249 /* Sign extend top half? */
250 if (high & ((unsigned HOST_WIDE_INT)1
251 << (prec - HOST_BITS_PER_WIDE_INT - 1)))
252 high |= (HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT);
253 }
254 else if (prec == HOST_BITS_PER_WIDE_INT)
255 {
256 if ((HOST_WIDE_INT)low < 0)
257 high = -1;
258 }
259 else
260 {
261 /* Sign extend bottom half? */
262 if (low & ((unsigned HOST_WIDE_INT)1 << (prec - 1)))
2bc77e10 263 {
4d28c5d1 264 high = -1;
265 low |= (HOST_WIDE_INT)(-1) << prec;
2bc77e10 266 }
267 }
f55401f0 268
4d28c5d1 269 /* If the value changed, return a new node. */
270 if (overflowed || overflowed_const
271 || low != TREE_INT_CST_LOW (t) || high != TREE_INT_CST_HIGH (t))
272 {
7016c612 273 t = build_int_cst_wide (TREE_TYPE (t), low, high);
0c5713a2 274
4d28c5d1 275 if (overflowed
276 || overflowable < 0
277 || (overflowable > 0 && sign_extended_type))
278 {
00b76131 279 t = copy_node (t);
4d28c5d1 280 TREE_OVERFLOW (t) = 1;
281 TREE_CONSTANT_OVERFLOW (t) = 1;
282 }
283 else if (overflowed_const)
00b76131 284 {
285 t = copy_node (t);
286 TREE_CONSTANT_OVERFLOW (t) = 1;
287 }
4d28c5d1 288 }
0c5713a2 289
4d28c5d1 290 return t;
2bc77e10 291}
292\f
b572011e 293/* Add two doubleword integers with doubleword result.
81035ec1 294 Return nonzero if the operation overflows according to UNSIGNED_P.
b572011e 295 Each argument is given as two `HOST_WIDE_INT' pieces.
2bc77e10 296 One argument is L1 and H1; the other, L2 and H2.
bd5b3bce 297 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 298
b9e999f0 299int
81035ec1 300add_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
301 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
302 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
303 bool unsigned_p)
2bc77e10 304{
a0c2c45b 305 unsigned HOST_WIDE_INT l;
306 HOST_WIDE_INT h;
2bc77e10 307
bd5b3bce 308 l = l1 + l2;
a0c2c45b 309 h = h1 + h2 + (l < l1);
2bc77e10 310
bd5b3bce 311 *lv = l;
312 *hv = h;
81035ec1 313
314 if (unsigned_p)
315 return (unsigned HOST_WIDE_INT) h < (unsigned HOST_WIDE_INT) h1;
316 else
317 return OVERFLOW_SUM_SIGN (h1, h2, h);
2bc77e10 318}
319
b572011e 320/* Negate a doubleword integer with doubleword result.
b9e999f0 321 Return nonzero if the operation overflows, assuming it's signed.
b572011e 322 The argument is given as two `HOST_WIDE_INT' pieces in L1 and H1.
bd5b3bce 323 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 324
b9e999f0 325int
dc81944a 326neg_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
327 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
2bc77e10 328{
329 if (l1 == 0)
330 {
331 *lv = 0;
332 *hv = - h1;
f55401f0 333 return (*hv & h1) < 0;
2bc77e10 334 }
335 else
336 {
cc049fa3 337 *lv = -l1;
338 *hv = ~h1;
b9e999f0 339 return 0;
2bc77e10 340 }
341}
342\f
b572011e 343/* Multiply two doubleword integers with doubleword result.
81035ec1 344 Return nonzero if the operation overflows according to UNSIGNED_P.
b572011e 345 Each argument is given as two `HOST_WIDE_INT' pieces.
2bc77e10 346 One argument is L1 and H1; the other, L2 and H2.
bd5b3bce 347 The value is stored as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 348
b9e999f0 349int
81035ec1 350mul_double_with_sign (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
351 unsigned HOST_WIDE_INT l2, HOST_WIDE_INT h2,
352 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
353 bool unsigned_p)
2bc77e10 354{
bd5b3bce 355 HOST_WIDE_INT arg1[4];
356 HOST_WIDE_INT arg2[4];
357 HOST_WIDE_INT prod[4 * 2];
19cb6b50 358 unsigned HOST_WIDE_INT carry;
359 int i, j, k;
a0c2c45b 360 unsigned HOST_WIDE_INT toplow, neglow;
361 HOST_WIDE_INT tophigh, neghigh;
2bc77e10 362
2bc77e10 363 encode (arg1, l1, h1);
364 encode (arg2, l2, h2);
365
f0af5a88 366 memset (prod, 0, sizeof prod);
2bc77e10 367
bd5b3bce 368 for (i = 0; i < 4; i++)
369 {
370 carry = 0;
371 for (j = 0; j < 4; j++)
372 {
373 k = i + j;
374 /* This product is <= 0xFFFE0001, the sum <= 0xFFFF0000. */
375 carry += arg1[i] * arg2[j];
376 /* Since prod[p] < 0xFFFF, this sum <= 0xFFFFFFFF. */
377 carry += prod[k];
378 prod[k] = LOWPART (carry);
379 carry = HIGHPART (carry);
380 }
381 prod[i + 4] = carry;
382 }
2bc77e10 383
81035ec1 384 decode (prod, lv, hv);
cc049fa3 385 decode (prod + 4, &toplow, &tophigh);
81035ec1 386
387 /* Unsigned overflow is immediate. */
388 if (unsigned_p)
389 return (toplow | tophigh) != 0;
390
391 /* Check for signed overflow by calculating the signed representation of the
392 top half of the result; it should agree with the low half's sign bit. */
b9e999f0 393 if (h1 < 0)
394 {
395 neg_double (l2, h2, &neglow, &neghigh);
396 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
397 }
398 if (h2 < 0)
399 {
400 neg_double (l1, h1, &neglow, &neghigh);
401 add_double (neglow, neghigh, toplow, tophigh, &toplow, &tophigh);
402 }
403 return (*hv < 0 ? ~(toplow & tophigh) : toplow | tophigh) != 0;
2bc77e10 404}
405\f
b572011e 406/* Shift the doubleword integer in L1, H1 left by COUNT places
2bc77e10 407 keeping only PREC bits of result.
408 Shift right if COUNT is negative.
409 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
b572011e 410 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 411
f55401f0 412void
dc81944a 413lshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
414 HOST_WIDE_INT count, unsigned int prec,
415 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv, int arith)
2bc77e10 416{
7c5b13dc 417 unsigned HOST_WIDE_INT signmask;
418
2bc77e10 419 if (count < 0)
420 {
cc049fa3 421 rshift_double (l1, h1, -count, prec, lv, hv, arith);
f55401f0 422 return;
2bc77e10 423 }
cc049fa3 424
0bb60c65 425 if (SHIFT_COUNT_TRUNCATED)
426 count %= prec;
2bc77e10 427
016d117a 428 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
429 {
430 /* Shifting by the host word size is undefined according to the
431 ANSI standard, so we must handle this as a special case. */
432 *hv = 0;
433 *lv = 0;
434 }
435 else if (count >= HOST_BITS_PER_WIDE_INT)
2bc77e10 436 {
a0c2c45b 437 *hv = l1 << (count - HOST_BITS_PER_WIDE_INT);
bd5b3bce 438 *lv = 0;
439 }
440 else
441 {
442 *hv = (((unsigned HOST_WIDE_INT) h1 << count)
a0c2c45b 443 | (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
444 *lv = l1 << count;
2bc77e10 445 }
7c5b13dc 446
447 /* Sign extend all bits that are beyond the precision. */
448
449 signmask = -((prec > HOST_BITS_PER_WIDE_INT
f9a532b0 450 ? ((unsigned HOST_WIDE_INT) *hv
d3371fcd 451 >> (prec - HOST_BITS_PER_WIDE_INT - 1))
7c5b13dc 452 : (*lv >> (prec - 1))) & 1);
453
454 if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
455 ;
456 else if (prec >= HOST_BITS_PER_WIDE_INT)
457 {
458 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
459 *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
460 }
461 else
462 {
463 *hv = signmask;
464 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
465 *lv |= signmask << prec;
466 }
2bc77e10 467}
468
b572011e 469/* Shift the doubleword integer in L1, H1 right by COUNT places
2bc77e10 470 keeping only PREC bits of result. COUNT must be positive.
471 ARITH nonzero specifies arithmetic shifting; otherwise use logical shift.
b572011e 472 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 473
474void
dc81944a 475rshift_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
476 HOST_WIDE_INT count, unsigned int prec,
477 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv,
de1b648b 478 int arith)
2bc77e10 479{
bd5b3bce 480 unsigned HOST_WIDE_INT signmask;
a0c2c45b 481
bd5b3bce 482 signmask = (arith
483 ? -((unsigned HOST_WIDE_INT) h1 >> (HOST_BITS_PER_WIDE_INT - 1))
484 : 0);
2bc77e10 485
0bb60c65 486 if (SHIFT_COUNT_TRUNCATED)
487 count %= prec;
2bc77e10 488
016d117a 489 if (count >= 2 * HOST_BITS_PER_WIDE_INT)
490 {
491 /* Shifting by the host word size is undefined according to the
492 ANSI standard, so we must handle this as a special case. */
7c5b13dc 493 *hv = 0;
494 *lv = 0;
016d117a 495 }
496 else if (count >= HOST_BITS_PER_WIDE_INT)
2bc77e10 497 {
7c5b13dc 498 *hv = 0;
499 *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
bd5b3bce 500 }
501 else
502 {
7c5b13dc 503 *hv = (unsigned HOST_WIDE_INT) h1 >> count;
a0c2c45b 504 *lv = ((l1 >> count)
5ee8fe30 505 | ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
7c5b13dc 506 }
507
508 /* Zero / sign extend all bits that are beyond the precision. */
509
510 if (count >= (HOST_WIDE_INT)prec)
511 {
512 *hv = signmask;
513 *lv = signmask;
514 }
515 else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
516 ;
517 else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
518 {
519 *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
520 *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
521 }
522 else
523 {
524 *hv = signmask;
525 *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
526 *lv |= signmask << (prec - count);
2bc77e10 527 }
2bc77e10 528}
529\f
bd5b3bce 530/* Rotate the doubleword integer in L1, H1 left by COUNT places
2bc77e10 531 keeping only PREC bits of result.
532 Rotate right if COUNT is negative.
b572011e 533 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 534
535void
dc81944a 536lrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
537 HOST_WIDE_INT count, unsigned int prec,
538 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
2bc77e10 539{
a0c2c45b 540 unsigned HOST_WIDE_INT s1l, s2l;
541 HOST_WIDE_INT s1h, s2h;
2bc77e10 542
7a1b56a9 543 count %= prec;
2bc77e10 544 if (count < 0)
7a1b56a9 545 count += prec;
2bc77e10 546
7a1b56a9 547 lshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
548 rshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
549 *lv = s1l | s2l;
550 *hv = s1h | s2h;
2bc77e10 551}
552
b572011e 553/* Rotate the doubleword integer in L1, H1 left by COUNT places
2bc77e10 554 keeping only PREC bits of result. COUNT must be positive.
b572011e 555 Store the value as two `HOST_WIDE_INT' pieces in *LV and *HV. */
2bc77e10 556
557void
dc81944a 558rrotate_double (unsigned HOST_WIDE_INT l1, HOST_WIDE_INT h1,
559 HOST_WIDE_INT count, unsigned int prec,
560 unsigned HOST_WIDE_INT *lv, HOST_WIDE_INT *hv)
2bc77e10 561{
a0c2c45b 562 unsigned HOST_WIDE_INT s1l, s2l;
563 HOST_WIDE_INT s1h, s2h;
2bc77e10 564
7a1b56a9 565 count %= prec;
566 if (count < 0)
567 count += prec;
2bc77e10 568
7a1b56a9 569 rshift_double (l1, h1, count, prec, &s1l, &s1h, 0);
570 lshift_double (l1, h1, prec - count, prec, &s2l, &s2h, 0);
571 *lv = s1l | s2l;
572 *hv = s1h | s2h;
2bc77e10 573}
574\f
b572011e 575/* Divide doubleword integer LNUM, HNUM by doubleword integer LDEN, HDEN
2bc77e10 576 for a quotient (stored in *LQUO, *HQUO) and remainder (in *LREM, *HREM).
577 CODE is a tree code for a kind of division, one of
578 TRUNC_DIV_EXPR, FLOOR_DIV_EXPR, CEIL_DIV_EXPR, ROUND_DIV_EXPR
579 or EXACT_DIV_EXPR
20dd417a 580 It controls how the quotient is rounded to an integer.
b9e999f0 581 Return nonzero if the operation overflows.
2bc77e10 582 UNS nonzero says do unsigned division. */
583
15ca565e 584int
de1b648b 585div_and_round_double (enum tree_code code, int uns,
586 unsigned HOST_WIDE_INT lnum_orig, /* num == numerator == dividend */
587 HOST_WIDE_INT hnum_orig,
588 unsigned HOST_WIDE_INT lden_orig, /* den == denominator == divisor */
dc81944a 589 HOST_WIDE_INT hden_orig,
590 unsigned HOST_WIDE_INT *lquo,
de1b648b 591 HOST_WIDE_INT *hquo, unsigned HOST_WIDE_INT *lrem,
592 HOST_WIDE_INT *hrem)
2bc77e10 593{
594 int quo_neg = 0;
bd5b3bce 595 HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
596 HOST_WIDE_INT den[4], quo[4];
19cb6b50 597 int i, j;
bd5b3bce 598 unsigned HOST_WIDE_INT work;
a0c2c45b 599 unsigned HOST_WIDE_INT carry = 0;
600 unsigned HOST_WIDE_INT lnum = lnum_orig;
abd9ac9c 601 HOST_WIDE_INT hnum = hnum_orig;
a0c2c45b 602 unsigned HOST_WIDE_INT lden = lden_orig;
abd9ac9c 603 HOST_WIDE_INT hden = hden_orig;
b9e999f0 604 int overflow = 0;
2bc77e10 605
a0c2c45b 606 if (hden == 0 && lden == 0)
ad87de1e 607 overflow = 1, lden = 1;
2bc77e10 608
139c3f48 609 /* Calculate quotient sign and convert operands to unsigned. */
cc049fa3 610 if (!uns)
2bc77e10 611 {
b9e999f0 612 if (hnum < 0)
2bc77e10 613 {
614 quo_neg = ~ quo_neg;
b9e999f0 615 /* (minimum integer) / (-1) is the only overflow case. */
a0c2c45b 616 if (neg_double (lnum, hnum, &lnum, &hnum)
617 && ((HOST_WIDE_INT) lden & hden) == -1)
b9e999f0 618 overflow = 1;
2bc77e10 619 }
cc049fa3 620 if (hden < 0)
2bc77e10 621 {
622 quo_neg = ~ quo_neg;
b9e999f0 623 neg_double (lden, hden, &lden, &hden);
2bc77e10 624 }
625 }
626
627 if (hnum == 0 && hden == 0)
628 { /* single precision */
629 *hquo = *hrem = 0;
802ddb63 630 /* This unsigned division rounds toward zero. */
a0c2c45b 631 *lquo = lnum / lden;
2bc77e10 632 goto finish_up;
633 }
634
635 if (hnum == 0)
636 { /* trivial case: dividend < divisor */
637 /* hden != 0 already checked. */
638 *hquo = *lquo = 0;
639 *hrem = hnum;
640 *lrem = lnum;
641 goto finish_up;
642 }
643
f0af5a88 644 memset (quo, 0, sizeof quo);
2bc77e10 645
f0af5a88 646 memset (num, 0, sizeof num); /* to zero 9th element */
647 memset (den, 0, sizeof den);
2bc77e10 648
cc049fa3 649 encode (num, lnum, hnum);
2bc77e10 650 encode (den, lden, hden);
651
bd5b3bce 652 /* Special code for when the divisor < BASE. */
a0c2c45b 653 if (hden == 0 && lden < (unsigned HOST_WIDE_INT) BASE)
bd5b3bce 654 {
2bc77e10 655 /* hnum != 0 already checked. */
bd5b3bce 656 for (i = 4 - 1; i >= 0; i--)
2bc77e10 657 {
bd5b3bce 658 work = num[i] + carry * BASE;
a0c2c45b 659 quo[i] = work / lden;
660 carry = work % lden;
2bc77e10 661 }
662 }
bd5b3bce 663 else
664 {
665 /* Full double precision division,
666 with thanks to Don Knuth's "Seminumerical Algorithms". */
a0c2c45b 667 int num_hi_sig, den_hi_sig;
668 unsigned HOST_WIDE_INT quo_est, scale;
2bc77e10 669
6ef828f9 670 /* Find the highest nonzero divisor digit. */
cc049fa3 671 for (i = 4 - 1;; i--)
672 if (den[i] != 0)
673 {
674 den_hi_sig = i;
675 break;
676 }
bd5b3bce 677
a0c2c45b 678 /* Insure that the first digit of the divisor is at least BASE/2.
679 This is required by the quotient digit estimation algorithm. */
2bc77e10 680
a0c2c45b 681 scale = BASE / (den[den_hi_sig] + 1);
682 if (scale > 1)
683 { /* scale divisor and dividend */
684 carry = 0;
685 for (i = 0; i <= 4 - 1; i++)
686 {
687 work = (num[i] * scale) + carry;
688 num[i] = LOWPART (work);
689 carry = HIGHPART (work);
690 }
2bc77e10 691
a0c2c45b 692 num[4] = carry;
693 carry = 0;
694 for (i = 0; i <= 4 - 1; i++)
695 {
696 work = (den[i] * scale) + carry;
697 den[i] = LOWPART (work);
698 carry = HIGHPART (work);
699 if (den[i] != 0) den_hi_sig = i;
700 }
701 }
2bc77e10 702
a0c2c45b 703 num_hi_sig = 4;
2bc77e10 704
a0c2c45b 705 /* Main loop */
706 for (i = num_hi_sig - den_hi_sig - 1; i >= 0; i--)
2bc77e10 707 {
a0c2c45b 708 /* Guess the next quotient digit, quo_est, by dividing the first
709 two remaining dividend digits by the high order quotient digit.
710 quo_est is never low and is at most 2 high. */
711 unsigned HOST_WIDE_INT tmp;
712
713 num_hi_sig = i + den_hi_sig + 1;
714 work = num[num_hi_sig] * BASE + num[num_hi_sig - 1];
715 if (num[num_hi_sig] != den[den_hi_sig])
716 quo_est = work / den[den_hi_sig];
717 else
718 quo_est = BASE - 1;
2bc77e10 719
1e625a2e 720 /* Refine quo_est so it's usually correct, and at most one high. */
a0c2c45b 721 tmp = work - quo_est * den[den_hi_sig];
722 if (tmp < BASE
723 && (den[den_hi_sig - 1] * quo_est
724 > (tmp * BASE + num[num_hi_sig - 2])))
725 quo_est--;
2bc77e10 726
a0c2c45b 727 /* Try QUO_EST as the quotient digit, by multiplying the
728 divisor by QUO_EST and subtracting from the remaining dividend.
729 Keep in mind that QUO_EST is the I - 1st digit. */
730
731 carry = 0;
2bc77e10 732 for (j = 0; j <= den_hi_sig; j++)
733 {
a0c2c45b 734 work = quo_est * den[j] + carry;
bd5b3bce 735 carry = HIGHPART (work);
a0c2c45b 736 work = num[i + j] - LOWPART (work);
bd5b3bce 737 num[i + j] = LOWPART (work);
a0c2c45b 738 carry += HIGHPART (work) != 0;
2bc77e10 739 }
2bc77e10 740
a0c2c45b 741 /* If quo_est was high by one, then num[i] went negative and
742 we need to correct things. */
f9a532b0 743 if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
a0c2c45b 744 {
745 quo_est--;
746 carry = 0; /* add divisor back in */
747 for (j = 0; j <= den_hi_sig; j++)
748 {
749 work = num[i + j] + den[j] + carry;
750 carry = HIGHPART (work);
751 num[i + j] = LOWPART (work);
752 }
753
754 num [num_hi_sig] += carry;
755 }
756
757 /* Store the quotient digit. */
758 quo[i] = quo_est;
759 }
2bc77e10 760 }
2bc77e10 761
762 decode (quo, lquo, hquo);
763
764 finish_up:
b4b174c3 765 /* If result is negative, make it so. */
2bc77e10 766 if (quo_neg)
767 neg_double (*lquo, *hquo, lquo, hquo);
768
aab2cf92 769 /* Compute trial remainder: rem = num - (quo * den) */
2bc77e10 770 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
771 neg_double (*lrem, *hrem, lrem, hrem);
772 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
773
774 switch (code)
775 {
776 case TRUNC_DIV_EXPR:
777 case TRUNC_MOD_EXPR: /* round toward zero */
778 case EXACT_DIV_EXPR: /* for this one, it shouldn't matter */
b9e999f0 779 return overflow;
2bc77e10 780
781 case FLOOR_DIV_EXPR:
782 case FLOOR_MOD_EXPR: /* round toward negative infinity */
783 if (quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio < 0 && rem != 0 */
784 {
785 /* quo = quo - 1; */
b572011e 786 add_double (*lquo, *hquo, (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1,
787 lquo, hquo);
2bc77e10 788 }
a0c2c45b 789 else
790 return overflow;
2bc77e10 791 break;
792
793 case CEIL_DIV_EXPR:
794 case CEIL_MOD_EXPR: /* round toward positive infinity */
795 if (!quo_neg && (*lrem != 0 || *hrem != 0)) /* ratio > 0 && rem != 0 */
796 {
b572011e 797 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
798 lquo, hquo);
2bc77e10 799 }
a0c2c45b 800 else
801 return overflow;
2bc77e10 802 break;
cc049fa3 803
2bc77e10 804 case ROUND_DIV_EXPR:
805 case ROUND_MOD_EXPR: /* round to closest integer */
806 {
a0c2c45b 807 unsigned HOST_WIDE_INT labs_rem = *lrem;
808 HOST_WIDE_INT habs_rem = *hrem;
809 unsigned HOST_WIDE_INT labs_den = lden, ltwice;
810 HOST_WIDE_INT habs_den = hden, htwice;
811
2358393e 812 /* Get absolute values. */
a0c2c45b 813 if (*hrem < 0)
814 neg_double (*lrem, *hrem, &labs_rem, &habs_rem);
815 if (hden < 0)
816 neg_double (lden, hden, &labs_den, &habs_den);
817
818 /* If (2 * abs (lrem) >= abs (lden)) */
b572011e 819 mul_double ((HOST_WIDE_INT) 2, (HOST_WIDE_INT) 0,
820 labs_rem, habs_rem, &ltwice, &htwice);
a0c2c45b 821
b572011e 822 if (((unsigned HOST_WIDE_INT) habs_den
823 < (unsigned HOST_WIDE_INT) htwice)
824 || (((unsigned HOST_WIDE_INT) habs_den
825 == (unsigned HOST_WIDE_INT) htwice)
a0c2c45b 826 && (labs_den < ltwice)))
2bc77e10 827 {
828 if (*hquo < 0)
829 /* quo = quo - 1; */
b572011e 830 add_double (*lquo, *hquo,
831 (HOST_WIDE_INT) -1, (HOST_WIDE_INT) -1, lquo, hquo);
2bc77e10 832 else
833 /* quo = quo + 1; */
b572011e 834 add_double (*lquo, *hquo, (HOST_WIDE_INT) 1, (HOST_WIDE_INT) 0,
835 lquo, hquo);
2bc77e10 836 }
a0c2c45b 837 else
838 return overflow;
2bc77e10 839 }
840 break;
841
842 default:
fdada98f 843 gcc_unreachable ();
2bc77e10 844 }
845
21dda4ee 846 /* Compute true remainder: rem = num - (quo * den) */
2bc77e10 847 mul_double (*lquo, *hquo, lden_orig, hden_orig, lrem, hrem);
848 neg_double (*lrem, *hrem, lrem, hrem);
849 add_double (lnum_orig, hnum_orig, *lrem, *hrem, lrem, hrem);
b9e999f0 850 return overflow;
2bc77e10 851}
86f023fe 852
853/* If ARG2 divides ARG1 with zero remainder, carries out the division
854 of type CODE and returns the quotient.
855 Otherwise returns NULL_TREE. */
856
857static tree
858div_if_zero_remainder (enum tree_code code, tree arg1, tree arg2)
859{
860 unsigned HOST_WIDE_INT int1l, int2l;
861 HOST_WIDE_INT int1h, int2h;
862 unsigned HOST_WIDE_INT quol, reml;
863 HOST_WIDE_INT quoh, remh;
864 tree type = TREE_TYPE (arg1);
865 int uns = TYPE_UNSIGNED (type);
866
867 int1l = TREE_INT_CST_LOW (arg1);
868 int1h = TREE_INT_CST_HIGH (arg1);
869 int2l = TREE_INT_CST_LOW (arg2);
870 int2h = TREE_INT_CST_HIGH (arg2);
871
872 div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
873 &quol, &quoh, &reml, &remh);
874 if (remh != 0 || reml != 0)
875 return NULL_TREE;
876
877 return build_int_cst_wide (type, quol, quoh);
878}
2bc77e10 879\f
352e5c7a 880/* Return true if the built-in mathematical function specified by CODE
881 is odd, i.e. -f(x) == f(-x). */
bd214d13 882
883static bool
884negate_mathfn_p (enum built_in_function code)
885{
886 switch (code)
887 {
4f35b1fc 888 CASE_FLT_FN (BUILT_IN_ASIN):
889 CASE_FLT_FN (BUILT_IN_ASINH):
890 CASE_FLT_FN (BUILT_IN_ATAN):
891 CASE_FLT_FN (BUILT_IN_ATANH):
892 CASE_FLT_FN (BUILT_IN_CBRT):
893 CASE_FLT_FN (BUILT_IN_SIN):
894 CASE_FLT_FN (BUILT_IN_SINH):
895 CASE_FLT_FN (BUILT_IN_TAN):
896 CASE_FLT_FN (BUILT_IN_TANH):
bd214d13 897 return true;
898
899 default:
900 break;
901 }
902 return false;
903}
904
bb445479 905/* Check whether we may negate an integer constant T without causing
906 overflow. */
907
908bool
909may_negate_without_overflow_p (tree t)
910{
911 unsigned HOST_WIDE_INT val;
912 unsigned int prec;
913 tree type;
914
fdada98f 915 gcc_assert (TREE_CODE (t) == INTEGER_CST);
bb445479 916
917 type = TREE_TYPE (t);
918 if (TYPE_UNSIGNED (type))
919 return false;
920
921 prec = TYPE_PRECISION (type);
922 if (prec > HOST_BITS_PER_WIDE_INT)
923 {
924 if (TREE_INT_CST_LOW (t) != 0)
925 return true;
926 prec -= HOST_BITS_PER_WIDE_INT;
927 val = TREE_INT_CST_HIGH (t);
928 }
929 else
930 val = TREE_INT_CST_LOW (t);
931 if (prec < HOST_BITS_PER_WIDE_INT)
932 val &= ((unsigned HOST_WIDE_INT) 1 << prec) - 1;
933 return val != ((unsigned HOST_WIDE_INT) 1 << (prec - 1));
934}
935
22331643 936/* Determine whether an expression T can be cheaply negated using
58b22aa6 937 the function negate_expr without introducing undefined overflow. */
22331643 938
939static bool
de1b648b 940negate_expr_p (tree t)
22331643 941{
22331643 942 tree type;
943
944 if (t == 0)
945 return false;
946
947 type = TREE_TYPE (t);
948
949 STRIP_SIGN_NOPS (t);
950 switch (TREE_CODE (t))
951 {
952 case INTEGER_CST:
58b22aa6 953 if (TYPE_UNSIGNED (type)
954 || (flag_wrapv && ! flag_trapv))
bd214d13 955 return true;
22331643 956
957 /* Check that -CST will not overflow type. */
bb445479 958 return may_negate_without_overflow_p (t);
5ea8b65a 959 case BIT_NOT_EXPR:
2ba580f0 960 return INTEGRAL_TYPE_P (type)
961 && (TYPE_UNSIGNED (type)
962 || (flag_wrapv && !flag_trapv));
22331643 963
964 case REAL_CST:
965 case NEGATE_EXPR:
22331643 966 return true;
967
bd214d13 968 case COMPLEX_CST:
969 return negate_expr_p (TREE_REALPART (t))
970 && negate_expr_p (TREE_IMAGPART (t));
971
2169cab6 972 case PLUS_EXPR:
973 if (FLOAT_TYPE_P (type) && !flag_unsafe_math_optimizations)
974 return false;
975 /* -(A + B) -> (-B) - A. */
976 if (negate_expr_p (TREE_OPERAND (t, 1))
977 && reorder_operands_p (TREE_OPERAND (t, 0),
978 TREE_OPERAND (t, 1)))
979 return true;
980 /* -(A + B) -> (-A) - B. */
981 return negate_expr_p (TREE_OPERAND (t, 0));
982
d842742d 983 case MINUS_EXPR:
984 /* We can't turn -(A-B) into B-A when we honor signed zeros. */
bd214d13 985 return (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
986 && reorder_operands_p (TREE_OPERAND (t, 0),
987 TREE_OPERAND (t, 1));
d842742d 988
a12ecaaa 989 case MULT_EXPR:
78a8ed03 990 if (TYPE_UNSIGNED (TREE_TYPE (t)))
a12ecaaa 991 break;
992
993 /* Fall through. */
994
995 case RDIV_EXPR:
996 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (TREE_TYPE (t))))
997 return negate_expr_p (TREE_OPERAND (t, 1))
998 || negate_expr_p (TREE_OPERAND (t, 0));
999 break;
1000
212f6d6d 1001 case TRUNC_DIV_EXPR:
1002 case ROUND_DIV_EXPR:
1003 case FLOOR_DIV_EXPR:
1004 case CEIL_DIV_EXPR:
1005 case EXACT_DIV_EXPR:
1006 if (TYPE_UNSIGNED (TREE_TYPE (t)) || flag_wrapv)
1007 break;
1008 return negate_expr_p (TREE_OPERAND (t, 1))
1009 || negate_expr_p (TREE_OPERAND (t, 0));
1010
bd214d13 1011 case NOP_EXPR:
1012 /* Negate -((double)float) as (double)(-float). */
1013 if (TREE_CODE (type) == REAL_TYPE)
1014 {
1015 tree tem = strip_float_extensions (t);
1016 if (tem != t)
1017 return negate_expr_p (tem);
1018 }
1019 break;
1020
1021 case CALL_EXPR:
1022 /* Negate -f(x) as f(-x). */
1023 if (negate_mathfn_p (builtin_mathfn_code (t)))
1024 return negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1)));
1025 break;
1026
a22fd555 1027 case RSHIFT_EXPR:
1028 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1029 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1030 {
1031 tree op1 = TREE_OPERAND (t, 1);
1032 if (TREE_INT_CST_HIGH (op1) == 0
1033 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1034 == TREE_INT_CST_LOW (op1))
1035 return true;
1036 }
1037 break;
1038
22331643 1039 default:
1040 break;
1041 }
1042 return false;
1043}
1044
58b22aa6 1045/* Given T, an expression, return a folded tree for -T or NULL_TREE, if no
1046 simplification is possible.
1047 If negate_expr_p would return true for T, NULL_TREE will never be
1048 returned. */
2bc77e10 1049
23ec2d5e 1050static tree
58b22aa6 1051fold_negate_expr (tree t)
23ec2d5e 1052{
58b22aa6 1053 tree type = TREE_TYPE (t);
23ec2d5e 1054 tree tem;
1055
23ec2d5e 1056 switch (TREE_CODE (t))
1057 {
5ea8b65a 1058 /* Convert - (~A) to A + 1. */
1059 case BIT_NOT_EXPR:
58b22aa6 1060 if (INTEGRAL_TYPE_P (type))
5ea8b65a 1061 return fold_build2 (PLUS_EXPR, type, TREE_OPERAND (t, 0),
1062 build_int_cst (type, 1));
3a07b940 1063 break;
5ea8b65a 1064
23ec2d5e 1065 case INTEGER_CST:
9d77437d 1066 tem = fold_negate_const (t, type);
bd214d13 1067 if (! TREE_OVERFLOW (tem)
78a8ed03 1068 || TYPE_UNSIGNED (type)
bd214d13 1069 || ! flag_trapv)
23ec2d5e 1070 return tem;
1071 break;
1072
a12ecaaa 1073 case REAL_CST:
9d77437d 1074 tem = fold_negate_const (t, type);
a12ecaaa 1075 /* Two's complement FP formats, such as c4x, may overflow. */
bd214d13 1076 if (! TREE_OVERFLOW (tem) || ! flag_trapping_math)
58b22aa6 1077 return tem;
a12ecaaa 1078 break;
1079
bd214d13 1080 case COMPLEX_CST:
1081 {
1082 tree rpart = negate_expr (TREE_REALPART (t));
1083 tree ipart = negate_expr (TREE_IMAGPART (t));
1084
1085 if ((TREE_CODE (rpart) == REAL_CST
1086 && TREE_CODE (ipart) == REAL_CST)
1087 || (TREE_CODE (rpart) == INTEGER_CST
1088 && TREE_CODE (ipart) == INTEGER_CST))
1089 return build_complex (type, rpart, ipart);
1090 }
1091 break;
1092
23ec2d5e 1093 case NEGATE_EXPR:
58b22aa6 1094 return TREE_OPERAND (t, 0);
23ec2d5e 1095
2169cab6 1096 case PLUS_EXPR:
1097 if (! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1098 {
1099 /* -(A + B) -> (-B) - A. */
1100 if (negate_expr_p (TREE_OPERAND (t, 1))
1101 && reorder_operands_p (TREE_OPERAND (t, 0),
1102 TREE_OPERAND (t, 1)))
fd96eeef 1103 {
1104 tem = negate_expr (TREE_OPERAND (t, 1));
58b22aa6 1105 return fold_build2 (MINUS_EXPR, type,
1106 tem, TREE_OPERAND (t, 0));
fd96eeef 1107 }
1108
2169cab6 1109 /* -(A + B) -> (-A) - B. */
1110 if (negate_expr_p (TREE_OPERAND (t, 0)))
fd96eeef 1111 {
1112 tem = negate_expr (TREE_OPERAND (t, 0));
58b22aa6 1113 return fold_build2 (MINUS_EXPR, type,
1114 tem, TREE_OPERAND (t, 1));
fd96eeef 1115 }
2169cab6 1116 }
1117 break;
1118
23ec2d5e 1119 case MINUS_EXPR:
1120 /* - (A - B) -> B - A */
bd214d13 1121 if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
1122 && reorder_operands_p (TREE_OPERAND (t, 0), TREE_OPERAND (t, 1)))
58b22aa6 1123 return fold_build2 (MINUS_EXPR, type,
1124 TREE_OPERAND (t, 1), TREE_OPERAND (t, 0));
23ec2d5e 1125 break;
1126
a12ecaaa 1127 case MULT_EXPR:
58b22aa6 1128 if (TYPE_UNSIGNED (type))
a12ecaaa 1129 break;
1130
1131 /* Fall through. */
1132
1133 case RDIV_EXPR:
58b22aa6 1134 if (! HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type)))
a12ecaaa 1135 {
1136 tem = TREE_OPERAND (t, 1);
1137 if (negate_expr_p (tem))
58b22aa6 1138 return fold_build2 (TREE_CODE (t), type,
1139 TREE_OPERAND (t, 0), negate_expr (tem));
a12ecaaa 1140 tem = TREE_OPERAND (t, 0);
1141 if (negate_expr_p (tem))
58b22aa6 1142 return fold_build2 (TREE_CODE (t), type,
1143 negate_expr (tem), TREE_OPERAND (t, 1));
a12ecaaa 1144 }
1145 break;
1146
212f6d6d 1147 case TRUNC_DIV_EXPR:
1148 case ROUND_DIV_EXPR:
1149 case FLOOR_DIV_EXPR:
1150 case CEIL_DIV_EXPR:
1151 case EXACT_DIV_EXPR:
58b22aa6 1152 if (!TYPE_UNSIGNED (type) && !flag_wrapv)
212f6d6d 1153 {
1154 tem = TREE_OPERAND (t, 1);
1155 if (negate_expr_p (tem))
58b22aa6 1156 return fold_build2 (TREE_CODE (t), type,
1157 TREE_OPERAND (t, 0), negate_expr (tem));
212f6d6d 1158 tem = TREE_OPERAND (t, 0);
1159 if (negate_expr_p (tem))
58b22aa6 1160 return fold_build2 (TREE_CODE (t), type,
1161 negate_expr (tem), TREE_OPERAND (t, 1));
212f6d6d 1162 }
1163 break;
1164
bd214d13 1165 case NOP_EXPR:
1166 /* Convert -((double)float) into (double)(-float). */
1167 if (TREE_CODE (type) == REAL_TYPE)
1168 {
1169 tem = strip_float_extensions (t);
1170 if (tem != t && negate_expr_p (tem))
58b22aa6 1171 return negate_expr (tem);
bd214d13 1172 }
1173 break;
1174
1175 case CALL_EXPR:
1176 /* Negate -f(x) as f(-x). */
1177 if (negate_mathfn_p (builtin_mathfn_code (t))
1178 && negate_expr_p (TREE_VALUE (TREE_OPERAND (t, 1))))
1179 {
1180 tree fndecl, arg, arglist;
1181
1182 fndecl = get_callee_fndecl (t);
1183 arg = negate_expr (TREE_VALUE (TREE_OPERAND (t, 1)));
1184 arglist = build_tree_list (NULL_TREE, arg);
1185 return build_function_call_expr (fndecl, arglist);
1186 }
1187 break;
1188
a22fd555 1189 case RSHIFT_EXPR:
1190 /* Optimize -((int)x >> 31) into (unsigned)x >> 31. */
1191 if (TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST)
1192 {
1193 tree op1 = TREE_OPERAND (t, 1);
1194 if (TREE_INT_CST_HIGH (op1) == 0
1195 && (unsigned HOST_WIDE_INT) (TYPE_PRECISION (type) - 1)
1196 == TREE_INT_CST_LOW (op1))
1197 {
78a8ed03 1198 tree ntype = TYPE_UNSIGNED (type)
fa8b888f 1199 ? lang_hooks.types.signed_type (type)
1200 : lang_hooks.types.unsigned_type (type);
a22fd555 1201 tree temp = fold_convert (ntype, TREE_OPERAND (t, 0));
7ab7fd4f 1202 temp = fold_build2 (RSHIFT_EXPR, ntype, temp, op1);
a22fd555 1203 return fold_convert (type, temp);
1204 }
1205 }
1206 break;
1207
23ec2d5e 1208 default:
1209 break;
1210 }
1211
58b22aa6 1212 return NULL_TREE;
1213}
1214
1215/* Like fold_negate_expr, but return a NEGATE_EXPR tree, if T can not be
1216 negated in a simpler way. Also allow for T to be NULL_TREE, in which case
1217 return NULL_TREE. */
1218
1219static tree
1220negate_expr (tree t)
1221{
1222 tree type, tem;
1223
1224 if (t == NULL_TREE)
1225 return NULL_TREE;
1226
1227 type = TREE_TYPE (t);
1228 STRIP_SIGN_NOPS (t);
1229
1230 tem = fold_negate_expr (t);
1231 if (!tem)
1232 tem = build1 (NEGATE_EXPR, TREE_TYPE (t), t);
b30e3dbc 1233 return fold_convert (type, tem);
23ec2d5e 1234}
1235\f
1236/* Split a tree IN into a constant, literal and variable parts that could be
1237 combined with CODE to make IN. "constant" means an expression with
1238 TREE_CONSTANT but that isn't an actual constant. CODE must be a
1239 commutative arithmetic operation. Store the constant part into *CONP,
b07ba9ff 1240 the literal in *LITP and return the variable part. If a part isn't
23ec2d5e 1241 present, set it to null. If the tree does not decompose in this way,
1242 return the entire tree as the variable part and the other parts as null.
1243
1244 If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
b07ba9ff 1245 case, we negate an operand that was subtracted. Except if it is a
1246 literal for which we use *MINUS_LITP instead.
1247
1248 If NEGATE_P is true, we are negating all of IN, again except a literal
1249 for which we use *MINUS_LITP instead.
23ec2d5e 1250
1251 If IN is itself a literal or constant, return it as appropriate.
1252
1253 Note that we do not guarantee that any of the three values will be the
1254 same type as IN, but they will have the same signedness and mode. */
1255
1256static tree
dc81944a 1257split_tree (tree in, enum tree_code code, tree *conp, tree *litp,
1258 tree *minus_litp, int negate_p)
2bc77e10 1259{
23ec2d5e 1260 tree var = 0;
1261
2bc77e10 1262 *conp = 0;
23ec2d5e 1263 *litp = 0;
b07ba9ff 1264 *minus_litp = 0;
23ec2d5e 1265
6312a35e 1266 /* Strip any conversions that don't change the machine mode or signedness. */
23ec2d5e 1267 STRIP_SIGN_NOPS (in);
1268
1269 if (TREE_CODE (in) == INTEGER_CST || TREE_CODE (in) == REAL_CST)
1270 *litp = in;
23ec2d5e 1271 else if (TREE_CODE (in) == code
1272 || (! FLOAT_TYPE_P (TREE_TYPE (in))
1273 /* We can associate addition and subtraction together (even
1274 though the C standard doesn't say so) for integers because
1275 the value is not affected. For reals, the value might be
1276 affected, so we can't. */
1277 && ((code == PLUS_EXPR && TREE_CODE (in) == MINUS_EXPR)
1278 || (code == MINUS_EXPR && TREE_CODE (in) == PLUS_EXPR))))
1279 {
1280 tree op0 = TREE_OPERAND (in, 0);
1281 tree op1 = TREE_OPERAND (in, 1);
1282 int neg1_p = TREE_CODE (in) == MINUS_EXPR;
1283 int neg_litp_p = 0, neg_conp_p = 0, neg_var_p = 0;
1284
1285 /* First see if either of the operands is a literal, then a constant. */
1286 if (TREE_CODE (op0) == INTEGER_CST || TREE_CODE (op0) == REAL_CST)
1287 *litp = op0, op0 = 0;
1288 else if (TREE_CODE (op1) == INTEGER_CST || TREE_CODE (op1) == REAL_CST)
1289 *litp = op1, neg_litp_p = neg1_p, op1 = 0;
1290
1291 if (op0 != 0 && TREE_CONSTANT (op0))
1292 *conp = op0, op0 = 0;
1293 else if (op1 != 0 && TREE_CONSTANT (op1))
1294 *conp = op1, neg_conp_p = neg1_p, op1 = 0;
1295
1296 /* If we haven't dealt with either operand, this is not a case we can
6312a35e 1297 decompose. Otherwise, VAR is either of the ones remaining, if any. */
23ec2d5e 1298 if (op0 != 0 && op1 != 0)
1299 var = in;
1300 else if (op0 != 0)
1301 var = op0;
1302 else
1303 var = op1, neg_var_p = neg1_p;
2bc77e10 1304
23ec2d5e 1305 /* Now do any needed negations. */
b07ba9ff 1306 if (neg_litp_p)
1307 *minus_litp = *litp, *litp = 0;
1308 if (neg_conp_p)
1309 *conp = negate_expr (*conp);
1310 if (neg_var_p)
1311 var = negate_expr (var);
23ec2d5e 1312 }
8541c166 1313 else if (TREE_CONSTANT (in))
1314 *conp = in;
23ec2d5e 1315 else
1316 var = in;
1317
1318 if (negate_p)
2bc77e10 1319 {
b07ba9ff 1320 if (*litp)
1321 *minus_litp = *litp, *litp = 0;
1322 else if (*minus_litp)
1323 *litp = *minus_litp, *minus_litp = 0;
23ec2d5e 1324 *conp = negate_expr (*conp);
b07ba9ff 1325 var = negate_expr (var);
2bc77e10 1326 }
23ec2d5e 1327
1328 return var;
1329}
1330
1331/* Re-associate trees split by the above function. T1 and T2 are either
1332 expressions to associate or null. Return the new expression, if any. If
b07ba9ff 1333 we build an operation, do it in TYPE and with CODE. */
23ec2d5e 1334
1335static tree
de1b648b 1336associate_trees (tree t1, tree t2, enum tree_code code, tree type)
23ec2d5e 1337{
23ec2d5e 1338 if (t1 == 0)
1339 return t2;
1340 else if (t2 == 0)
1341 return t1;
1342
23ec2d5e 1343 /* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
1344 try to fold this since we will have infinite recursion. But do
1345 deal with any NEGATE_EXPRs. */
1346 if (TREE_CODE (t1) == code || TREE_CODE (t2) == code
1347 || TREE_CODE (t1) == MINUS_EXPR || TREE_CODE (t2) == MINUS_EXPR)
1348 {
5a3fb4d3 1349 if (code == PLUS_EXPR)
1350 {
1351 if (TREE_CODE (t1) == NEGATE_EXPR)
fd96eeef 1352 return build2 (MINUS_EXPR, type, fold_convert (type, t2),
1353 fold_convert (type, TREE_OPERAND (t1, 0)));
5a3fb4d3 1354 else if (TREE_CODE (t2) == NEGATE_EXPR)
fd96eeef 1355 return build2 (MINUS_EXPR, type, fold_convert (type, t1),
1356 fold_convert (type, TREE_OPERAND (t2, 0)));
faab57e3 1357 else if (integer_zerop (t2))
1358 return fold_convert (type, t1);
5a3fb4d3 1359 }
faab57e3 1360 else if (code == MINUS_EXPR)
1361 {
1362 if (integer_zerop (t2))
1363 return fold_convert (type, t1);
1364 }
1365
fd96eeef 1366 return build2 (code, type, fold_convert (type, t1),
1367 fold_convert (type, t2));
23ec2d5e 1368 }
1369
7ab7fd4f 1370 return fold_build2 (code, type, fold_convert (type, t1),
1371 fold_convert (type, t2));
2bc77e10 1372}
1373\f
0dbd1c74 1374/* Combine two integer constants ARG1 and ARG2 under operation CODE
32cef1cc 1375 to produce a new constant. Return NULL_TREE if we don't know how
1376 to evaluate CODE at compile-time.
5485823f 1377
15d769aa 1378 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
2bc77e10 1379
4ee9c684 1380tree
de1b648b 1381int_const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
2bc77e10 1382{
a0c2c45b 1383 unsigned HOST_WIDE_INT int1l, int2l;
1384 HOST_WIDE_INT int1h, int2h;
1385 unsigned HOST_WIDE_INT low;
1386 HOST_WIDE_INT hi;
1387 unsigned HOST_WIDE_INT garbagel;
1388 HOST_WIDE_INT garbageh;
19cb6b50 1389 tree t;
15d769aa 1390 tree type = TREE_TYPE (arg1);
78a8ed03 1391 int uns = TYPE_UNSIGNED (type);
15d769aa 1392 int is_sizetype
1393 = (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type));
0dbd1c74 1394 int overflow = 0;
8ea862a9 1395
0dbd1c74 1396 int1l = TREE_INT_CST_LOW (arg1);
1397 int1h = TREE_INT_CST_HIGH (arg1);
1398 int2l = TREE_INT_CST_LOW (arg2);
1399 int2h = TREE_INT_CST_HIGH (arg2);
1400
1401 switch (code)
2bc77e10 1402 {
0dbd1c74 1403 case BIT_IOR_EXPR:
1404 low = int1l | int2l, hi = int1h | int2h;
1405 break;
2bc77e10 1406
0dbd1c74 1407 case BIT_XOR_EXPR:
1408 low = int1l ^ int2l, hi = int1h ^ int2h;
1409 break;
2bc77e10 1410
0dbd1c74 1411 case BIT_AND_EXPR:
1412 low = int1l & int2l, hi = int1h & int2h;
1413 break;
2bc77e10 1414
0dbd1c74 1415 case RSHIFT_EXPR:
cc049fa3 1416 int2l = -int2l;
0dbd1c74 1417 case LSHIFT_EXPR:
1418 /* It's unclear from the C standard whether shifts can overflow.
1419 The following code ignores overflow; perhaps a C standard
1420 interpretation ruling is needed. */
15d769aa 1421 lshift_double (int1l, int1h, int2l, TYPE_PRECISION (type),
02e7a332 1422 &low, &hi, !uns);
0dbd1c74 1423 break;
2bc77e10 1424
0dbd1c74 1425 case RROTATE_EXPR:
1426 int2l = - int2l;
1427 case LROTATE_EXPR:
15d769aa 1428 lrotate_double (int1l, int1h, int2l, TYPE_PRECISION (type),
0dbd1c74 1429 &low, &hi);
1430 break;
2bc77e10 1431
0dbd1c74 1432 case PLUS_EXPR:
1433 overflow = add_double (int1l, int1h, int2l, int2h, &low, &hi);
1434 break;
2bc77e10 1435
0dbd1c74 1436 case MINUS_EXPR:
1437 neg_double (int2l, int2h, &low, &hi);
1438 add_double (int1l, int1h, low, hi, &low, &hi);
083a2b5e 1439 overflow = OVERFLOW_SUM_SIGN (hi, int2h, int1h);
0dbd1c74 1440 break;
2bc77e10 1441
0dbd1c74 1442 case MULT_EXPR:
1443 overflow = mul_double (int1l, int1h, int2l, int2h, &low, &hi);
1444 break;
2bc77e10 1445
0dbd1c74 1446 case TRUNC_DIV_EXPR:
1447 case FLOOR_DIV_EXPR: case CEIL_DIV_EXPR:
1448 case EXACT_DIV_EXPR:
1449 /* This is a shortcut for a common special case. */
a0c2c45b 1450 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
0dbd1c74 1451 && ! TREE_CONSTANT_OVERFLOW (arg1)
1452 && ! TREE_CONSTANT_OVERFLOW (arg2)
a0c2c45b 1453 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
0dbd1c74 1454 {
1455 if (code == CEIL_DIV_EXPR)
1456 int1l += int2l - 1;
a0c2c45b 1457
0dbd1c74 1458 low = int1l / int2l, hi = 0;
2bc77e10 1459 break;
0dbd1c74 1460 }
2bc77e10 1461
6312a35e 1462 /* ... fall through ... */
2bc77e10 1463
cc049fa3 1464 case ROUND_DIV_EXPR:
32cef1cc 1465 if (int2h == 0 && int2l == 0)
1466 return NULL_TREE;
0dbd1c74 1467 if (int2h == 0 && int2l == 1)
1468 {
1469 low = int1l, hi = int1h;
2bc77e10 1470 break;
0dbd1c74 1471 }
1472 if (int1l == int2l && int1h == int2h
1473 && ! (int1l == 0 && int1h == 0))
1474 {
1475 low = 1, hi = 0;
c13e6dce 1476 break;
0dbd1c74 1477 }
15d769aa 1478 overflow = div_and_round_double (code, uns, int1l, int1h, int2l, int2h,
0dbd1c74 1479 &low, &hi, &garbagel, &garbageh);
1480 break;
c13e6dce 1481
0dbd1c74 1482 case TRUNC_MOD_EXPR:
1483 case FLOOR_MOD_EXPR: case CEIL_MOD_EXPR:
1484 /* This is a shortcut for a common special case. */
a0c2c45b 1485 if (int2h == 0 && (HOST_WIDE_INT) int2l > 0
0dbd1c74 1486 && ! TREE_CONSTANT_OVERFLOW (arg1)
1487 && ! TREE_CONSTANT_OVERFLOW (arg2)
a0c2c45b 1488 && int1h == 0 && (HOST_WIDE_INT) int1l >= 0)
0dbd1c74 1489 {
1490 if (code == CEIL_MOD_EXPR)
1491 int1l += int2l - 1;
1492 low = int1l % int2l, hi = 0;
c13e6dce 1493 break;
0dbd1c74 1494 }
c13e6dce 1495
6312a35e 1496 /* ... fall through ... */
0dbd1c74 1497
cc049fa3 1498 case ROUND_MOD_EXPR:
32cef1cc 1499 if (int2h == 0 && int2l == 0)
1500 return NULL_TREE;
0dbd1c74 1501 overflow = div_and_round_double (code, uns,
1502 int1l, int1h, int2l, int2h,
1503 &garbagel, &garbageh, &low, &hi);
1504 break;
1505
1506 case MIN_EXPR:
1507 case MAX_EXPR:
1508 if (uns)
083a2b5e 1509 low = (((unsigned HOST_WIDE_INT) int1h
1510 < (unsigned HOST_WIDE_INT) int2h)
1511 || (((unsigned HOST_WIDE_INT) int1h
1512 == (unsigned HOST_WIDE_INT) int2h)
a0c2c45b 1513 && int1l < int2l));
a3f1e3ec 1514 else
a0c2c45b 1515 low = (int1h < int2h
1516 || (int1h == int2h && int1l < int2l));
083a2b5e 1517
0dbd1c74 1518 if (low == (code == MIN_EXPR))
1519 low = int1l, hi = int1h;
1520 else
1521 low = int2l, hi = int2h;
1522 break;
8ea862a9 1523
0dbd1c74 1524 default:
32cef1cc 1525 return NULL_TREE;
8ea862a9 1526 }
0dbd1c74 1527
7016c612 1528 t = build_int_cst_wide (TREE_TYPE (arg1), low, hi);
0dbd1c74 1529
4d28c5d1 1530 if (notrunc)
1531 {
1532 /* Propagate overflow flags ourselves. */
1533 if (((!uns || is_sizetype) && overflow)
1534 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2))
00b76131 1535 {
1536 t = copy_node (t);
1537 TREE_OVERFLOW (t) = 1;
1538 TREE_CONSTANT_OVERFLOW (t) = 1;
1539 }
1540 else if (TREE_CONSTANT_OVERFLOW (arg1) | TREE_CONSTANT_OVERFLOW (arg2))
1541 {
1542 t = copy_node (t);
1543 TREE_CONSTANT_OVERFLOW (t) = 1;
1544 }
4d28c5d1 1545 }
1546 else
1547 t = force_fit_type (t, 1,
1548 ((!uns || is_sizetype) && overflow)
1549 | TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2),
1550 TREE_CONSTANT_OVERFLOW (arg1)
1551 | TREE_CONSTANT_OVERFLOW (arg2));
0c5713a2 1552
0dbd1c74 1553 return t;
1554}
1555
083a2b5e 1556/* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
1557 constant. We assume ARG1 and ARG2 have the same data type, or at least
0b6fa2ba 1558 are the same kind of constant and the same machine mode. Return zero if
1559 combining the constants is not allowed in the current operating mode.
0dbd1c74 1560
1561 If NOTRUNC is nonzero, do not truncate the result to fit the data type. */
1562
1563static tree
de1b648b 1564const_binop (enum tree_code code, tree arg1, tree arg2, int notrunc)
0dbd1c74 1565{
0b6fa2ba 1566 /* Sanity check for the recursive cases. */
1567 if (!arg1 || !arg2)
1568 return NULL_TREE;
1569
cc049fa3 1570 STRIP_NOPS (arg1);
1571 STRIP_NOPS (arg2);
0dbd1c74 1572
1573 if (TREE_CODE (arg1) == INTEGER_CST)
15d769aa 1574 return int_const_binop (code, arg1, arg2, notrunc);
0dbd1c74 1575
2bc77e10 1576 if (TREE_CODE (arg1) == REAL_CST)
1577 {
276beea2 1578 enum machine_mode mode;
9a24cfc6 1579 REAL_VALUE_TYPE d1;
1580 REAL_VALUE_TYPE d2;
536f5fb1 1581 REAL_VALUE_TYPE value;
a47b9d79 1582 REAL_VALUE_TYPE result;
1583 bool inexact;
276beea2 1584 tree t, type;
2bc77e10 1585
32cef1cc 1586 /* The following codes are handled by real_arithmetic. */
1587 switch (code)
1588 {
1589 case PLUS_EXPR:
1590 case MINUS_EXPR:
1591 case MULT_EXPR:
1592 case RDIV_EXPR:
1593 case MIN_EXPR:
1594 case MAX_EXPR:
1595 break;
1596
1597 default:
1598 return NULL_TREE;
1599 }
1600
9a24cfc6 1601 d1 = TREE_REAL_CST (arg1);
1602 d2 = TREE_REAL_CST (arg2);
9248d3e0 1603
276beea2 1604 type = TREE_TYPE (arg1);
1605 mode = TYPE_MODE (type);
1606
1607 /* Don't perform operation if we honor signaling NaNs and
1608 either operand is a NaN. */
1609 if (HONOR_SNANS (mode)
1610 && (REAL_VALUE_ISNAN (d1) || REAL_VALUE_ISNAN (d2)))
1611 return NULL_TREE;
1612
1613 /* Don't perform operation if it would raise a division
1614 by zero exception. */
1615 if (code == RDIV_EXPR
1616 && REAL_VALUES_EQUAL (d2, dconst0)
1617 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
1618 return NULL_TREE;
1619
9248d3e0 1620 /* If either operand is a NaN, just return it. Otherwise, set up
1621 for floating-point trap; we return an overflow. */
1622 if (REAL_VALUE_ISNAN (d1))
1623 return arg1;
1624 else if (REAL_VALUE_ISNAN (d2))
1625 return arg2;
70192c5e 1626
a47b9d79 1627 inexact = real_arithmetic (&value, code, &d1, &d2);
1628 real_convert (&result, mode, &value);
cc049fa3 1629
f2e0dda3 1630 /* Don't constant fold this floating point operation if
1631 the result has overflowed and flag_trapping_math. */
f2e0dda3 1632 if (flag_trapping_math
1633 && MODE_HAS_INFINITIES (mode)
1634 && REAL_VALUE_ISINF (result)
1635 && !REAL_VALUE_ISINF (d1)
1636 && !REAL_VALUE_ISINF (d2))
1637 return NULL_TREE;
1638
a47b9d79 1639 /* Don't constant fold this floating point operation if the
1640 result may dependent upon the run-time rounding mode and
09fde96c 1641 flag_rounding_math is set, or if GCC's software emulation
1642 is unable to accurately represent the result. */
09fde96c 1643 if ((flag_rounding_math
1644 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
1645 && !flag_unsafe_math_optimizations))
a47b9d79 1646 && (inexact || !real_identical (&result, &value)))
1647 return NULL_TREE;
1648
1649 t = build_real (type, result);
23fed9b2 1650
4d28c5d1 1651 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2);
23fed9b2 1652 TREE_CONSTANT_OVERFLOW (t)
1653 = TREE_OVERFLOW (t)
1654 | TREE_CONSTANT_OVERFLOW (arg1)
1655 | TREE_CONSTANT_OVERFLOW (arg2);
c0244247 1656 return t;
2bc77e10 1657 }
32cef1cc 1658
2bc77e10 1659 if (TREE_CODE (arg1) == COMPLEX_CST)
1660 {
19cb6b50 1661 tree type = TREE_TYPE (arg1);
1662 tree r1 = TREE_REALPART (arg1);
1663 tree i1 = TREE_IMAGPART (arg1);
1664 tree r2 = TREE_REALPART (arg2);
1665 tree i2 = TREE_IMAGPART (arg2);
0b6fa2ba 1666 tree real, imag;
2bc77e10 1667
1668 switch (code)
1669 {
1670 case PLUS_EXPR:
2bc77e10 1671 case MINUS_EXPR:
0b6fa2ba 1672 real = const_binop (code, r1, r2, notrunc);
1673 imag = const_binop (code, i1, i2, notrunc);
2bc77e10 1674 break;
1675
1676 case MULT_EXPR:
0b6fa2ba 1677 real = const_binop (MINUS_EXPR,
1678 const_binop (MULT_EXPR, r1, r2, notrunc),
1679 const_binop (MULT_EXPR, i1, i2, notrunc),
1680 notrunc);
1681 imag = const_binop (PLUS_EXPR,
1682 const_binop (MULT_EXPR, r1, i2, notrunc),
1683 const_binop (MULT_EXPR, i1, r2, notrunc),
1684 notrunc);
2bc77e10 1685 break;
1686
1687 case RDIV_EXPR:
1688 {
19cb6b50 1689 tree magsquared
2bc77e10 1690 = const_binop (PLUS_EXPR,
5485823f 1691 const_binop (MULT_EXPR, r2, r2, notrunc),
1692 const_binop (MULT_EXPR, i2, i2, notrunc),
1693 notrunc);
0b6fa2ba 1694 tree t1
1695 = const_binop (PLUS_EXPR,
1696 const_binop (MULT_EXPR, r1, r2, notrunc),
1697 const_binop (MULT_EXPR, i1, i2, notrunc),
1698 notrunc);
1699 tree t2
1700 = const_binop (MINUS_EXPR,
1701 const_binop (MULT_EXPR, i1, r2, notrunc),
1702 const_binop (MULT_EXPR, r1, i2, notrunc),
1703 notrunc);
86a914ce 1704
1705 if (INTEGRAL_TYPE_P (TREE_TYPE (r1)))
0b6fa2ba 1706 code = TRUNC_DIV_EXPR;
1707
1708 real = const_binop (code, t1, magsquared, notrunc);
1709 imag = const_binop (code, t2, magsquared, notrunc);
2bc77e10 1710 }
1711 break;
1712
1713 default:
32cef1cc 1714 return NULL_TREE;
2bc77e10 1715 }
0b6fa2ba 1716
1717 if (real && imag)
1718 return build_complex (type, real, imag);
2bc77e10 1719 }
0b6fa2ba 1720
32cef1cc 1721 return NULL_TREE;
2bc77e10 1722}
15d769aa 1723
85390276 1724/* Create a size type INT_CST node with NUMBER sign extended. KIND
1725 indicates which particular sizetype to create. */
083a2b5e 1726
902de8ed 1727tree
1e9d55d7 1728size_int_kind (HOST_WIDE_INT number, enum size_type_kind kind)
902de8ed 1729{
85390276 1730 return build_int_cst (sizetype_tab[(int) kind], number);
902de8ed 1731}
85390276 1732\f
902de8ed 1733/* Combine operands OP1 and OP2 with arithmetic operation CODE. CODE
1734 is a tree code. The type of the result is taken from the operands.
1735 Both must be the same type integer type and it must be a size type.
2bc77e10 1736 If the operands are constant, so is the result. */
1737
1738tree
de1b648b 1739size_binop (enum tree_code code, tree arg0, tree arg1)
2bc77e10 1740{
902de8ed 1741 tree type = TREE_TYPE (arg0);
1742
4a698d62 1743 if (arg0 == error_mark_node || arg1 == error_mark_node)
1744 return error_mark_node;
1745
fdada98f 1746 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1747 && type == TREE_TYPE (arg1));
902de8ed 1748
2bc77e10 1749 /* Handle the special case of two integer constants faster. */
1750 if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST)
1751 {
1752 /* And some specific cases even faster than that. */
a7baffe5 1753 if (code == PLUS_EXPR && integer_zerop (arg0))
2bc77e10 1754 return arg1;
a7baffe5 1755 else if ((code == MINUS_EXPR || code == PLUS_EXPR)
1756 && integer_zerop (arg1))
2bc77e10 1757 return arg0;
a7baffe5 1758 else if (code == MULT_EXPR && integer_onep (arg0))
2bc77e10 1759 return arg1;
a7baffe5 1760
2bc77e10 1761 /* Handle general case of two integer constants. */
15d769aa 1762 return int_const_binop (code, arg0, arg1, 0);
2bc77e10 1763 }
1764
7ab7fd4f 1765 return fold_build2 (code, type, arg0, arg1);
2bc77e10 1766}
3fd3b688 1767
902de8ed 1768/* Given two values, either both of sizetype or both of bitsizetype,
1769 compute the difference between the two values. Return the value
1770 in signed type corresponding to the type of the operands. */
3fd3b688 1771
1772tree
de1b648b 1773size_diffop (tree arg0, tree arg1)
3fd3b688 1774{
902de8ed 1775 tree type = TREE_TYPE (arg0);
1776 tree ctype;
3fd3b688 1777
fdada98f 1778 gcc_assert (TREE_CODE (type) == INTEGER_TYPE && TYPE_IS_SIZETYPE (type)
1779 && type == TREE_TYPE (arg1));
3fd3b688 1780
902de8ed 1781 /* If the type is already signed, just do the simple thing. */
78a8ed03 1782 if (!TYPE_UNSIGNED (type))
902de8ed 1783 return size_binop (MINUS_EXPR, arg0, arg1);
1784
e2134ab3 1785 ctype = type == bitsizetype ? sbitsizetype : ssizetype;
902de8ed 1786
1787 /* If either operand is not a constant, do the conversions to the signed
1788 type and subtract. The hardware will do the right thing with any
1789 overflow in the subtraction. */
1790 if (TREE_CODE (arg0) != INTEGER_CST || TREE_CODE (arg1) != INTEGER_CST)
b30e3dbc 1791 return size_binop (MINUS_EXPR, fold_convert (ctype, arg0),
1792 fold_convert (ctype, arg1));
902de8ed 1793
1794 /* If ARG0 is larger than ARG1, subtract and return the result in CTYPE.
1795 Otherwise, subtract the other way, convert to CTYPE (we know that can't
1796 overflow) and negate (which can't either). Special-case a result
1797 of zero while we're here. */
1798 if (tree_int_cst_equal (arg0, arg1))
3c6185f1 1799 return build_int_cst (ctype, 0);
902de8ed 1800 else if (tree_int_cst_lt (arg1, arg0))
b30e3dbc 1801 return fold_convert (ctype, size_binop (MINUS_EXPR, arg0, arg1));
902de8ed 1802 else
3c6185f1 1803 return size_binop (MINUS_EXPR, build_int_cst (ctype, 0),
b30e3dbc 1804 fold_convert (ctype, size_binop (MINUS_EXPR,
1805 arg1, arg0)));
3fd3b688 1806}
2bc77e10 1807\f
b38d56be 1808/* A subroutine of fold_convert_const handling conversions of an
1809 INTEGER_CST to another integer type. */
80db63ef 1810
1811static tree
b38d56be 1812fold_convert_const_int_from_int (tree type, tree arg1)
80db63ef 1813{
b38d56be 1814 tree t;
80db63ef 1815
b38d56be 1816 /* Given an integer constant, make new constant with new type,
1817 appropriately sign-extended or truncated. */
1818 t = build_int_cst_wide (type, TREE_INT_CST_LOW (arg1),
1819 TREE_INT_CST_HIGH (arg1));
1820
1821 t = force_fit_type (t,
1822 /* Don't set the overflow when
1823 converting a pointer */
1824 !POINTER_TYPE_P (TREE_TYPE (arg1)),
1825 (TREE_INT_CST_HIGH (arg1) < 0
1826 && (TYPE_UNSIGNED (type)
1827 < TYPE_UNSIGNED (TREE_TYPE (arg1))))
1828 | TREE_OVERFLOW (arg1),
1829 TREE_CONSTANT_OVERFLOW (arg1));
80db63ef 1830
b38d56be 1831 return t;
80db63ef 1832}
1833
b38d56be 1834/* A subroutine of fold_convert_const handling conversions a REAL_CST
1835 to an integer type. */
2bc77e10 1836
1837static tree
b38d56be 1838fold_convert_const_int_from_real (enum tree_code code, tree type, tree arg1)
2bc77e10 1839{
23fed9b2 1840 int overflow = 0;
04b253e8 1841 tree t;
1842
b38d56be 1843 /* The following code implements the floating point to integer
1844 conversion rules required by the Java Language Specification,
1845 that IEEE NaNs are mapped to zero and values that overflow
1846 the target precision saturate, i.e. values greater than
1847 INT_MAX are mapped to INT_MAX, and values less than INT_MIN
1848 are mapped to INT_MIN. These semantics are allowed by the
1849 C and C++ standards that simply state that the behavior of
1850 FP-to-integer conversion is unspecified upon overflow. */
2bc77e10 1851
b38d56be 1852 HOST_WIDE_INT high, low;
1853 REAL_VALUE_TYPE r;
1854 REAL_VALUE_TYPE x = TREE_REAL_CST (arg1);
1855
1856 switch (code)
2bc77e10 1857 {
b38d56be 1858 case FIX_TRUNC_EXPR:
1859 real_trunc (&r, VOIDmode, &x);
1860 break;
1861
1862 case FIX_CEIL_EXPR:
1863 real_ceil (&r, VOIDmode, &x);
1864 break;
1865
1866 case FIX_FLOOR_EXPR:
1867 real_floor (&r, VOIDmode, &x);
1868 break;
1869
1870 case FIX_ROUND_EXPR:
1871 real_round (&r, VOIDmode, &x);
1872 break;
1873
1874 default:
1875 gcc_unreachable ();
1876 }
1877
1878 /* If R is NaN, return zero and show we have an overflow. */
1879 if (REAL_VALUE_ISNAN (r))
1880 {
1881 overflow = 1;
1882 high = 0;
1883 low = 0;
1884 }
1885
1886 /* See if R is less than the lower bound or greater than the
1887 upper bound. */
1888
1889 if (! overflow)
1890 {
1891 tree lt = TYPE_MIN_VALUE (type);
1892 REAL_VALUE_TYPE l = real_value_from_int_cst (NULL_TREE, lt);
1893 if (REAL_VALUES_LESS (r, l))
2bc77e10 1894 {
b38d56be 1895 overflow = 1;
1896 high = TREE_INT_CST_HIGH (lt);
1897 low = TREE_INT_CST_LOW (lt);
2bc77e10 1898 }
b38d56be 1899 }
1900
1901 if (! overflow)
1902 {
1903 tree ut = TYPE_MAX_VALUE (type);
1904 if (ut)
2bc77e10 1905 {
b38d56be 1906 REAL_VALUE_TYPE u = real_value_from_int_cst (NULL_TREE, ut);
1907 if (REAL_VALUES_LESS (u, r))
04b253e8 1908 {
b38d56be 1909 overflow = 1;
1910 high = TREE_INT_CST_HIGH (ut);
1911 low = TREE_INT_CST_LOW (ut);
1912 }
1913 }
1914 }
04b253e8 1915
b38d56be 1916 if (! overflow)
1917 REAL_VALUE_TO_INT (&low, &high, r);
04b253e8 1918
b38d56be 1919 t = build_int_cst_wide (type, low, high);
04b253e8 1920
b38d56be 1921 t = force_fit_type (t, -1, overflow | TREE_OVERFLOW (arg1),
1922 TREE_CONSTANT_OVERFLOW (arg1));
1923 return t;
1924}
50c90ea2 1925
b38d56be 1926/* A subroutine of fold_convert_const handling conversions a REAL_CST
1927 to another floating point type. */
04b253e8 1928
b38d56be 1929static tree
1930fold_convert_const_real_from_real (tree type, tree arg1)
1931{
a47b9d79 1932 REAL_VALUE_TYPE value;
b38d56be 1933 tree t;
f52483b5 1934
a47b9d79 1935 real_convert (&value, TYPE_MODE (type), &TREE_REAL_CST (arg1));
1936 t = build_real (type, value);
67c65562 1937
b38d56be 1938 TREE_OVERFLOW (t) = TREE_OVERFLOW (arg1);
1939 TREE_CONSTANT_OVERFLOW (t)
1940 = TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
1941 return t;
1942}
67c65562 1943
b38d56be 1944/* Attempt to fold type conversion operation CODE of expression ARG1 to
1945 type TYPE. If no simplification can be done return NULL_TREE. */
67c65562 1946
b38d56be 1947static tree
1948fold_convert_const (enum tree_code code, tree type, tree arg1)
1949{
1950 if (TREE_TYPE (arg1) == type)
1951 return arg1;
4d28c5d1 1952
b38d56be 1953 if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
1954 {
1955 if (TREE_CODE (arg1) == INTEGER_CST)
1956 return fold_convert_const_int_from_int (type, arg1);
1957 else if (TREE_CODE (arg1) == REAL_CST)
1958 return fold_convert_const_int_from_real (code, type, arg1);
2bc77e10 1959 }
1960 else if (TREE_CODE (type) == REAL_TYPE)
1961 {
2bc77e10 1962 if (TREE_CODE (arg1) == INTEGER_CST)
1963 return build_real_from_int_cst (type, arg1);
2bc77e10 1964 if (TREE_CODE (arg1) == REAL_CST)
b38d56be 1965 return fold_convert_const_real_from_real (type, arg1);
2bc77e10 1966 }
04b253e8 1967 return NULL_TREE;
2bc77e10 1968}
b30e3dbc 1969
b38d56be 1970/* Construct a vector of zero elements of vector type TYPE. */
1971
1972static tree
1973build_zero_vector (tree type)
1974{
1975 tree elem, list;
1976 int i, units;
1977
1978 elem = fold_convert_const (NOP_EXPR, TREE_TYPE (type), integer_zero_node);
1979 units = TYPE_VECTOR_SUBPARTS (type);
1980
1981 list = NULL_TREE;
1982 for (i = 0; i < units; i++)
1983 list = tree_cons (NULL_TREE, elem, list);
1984 return build_vector (type, list);
1985}
1986
b30e3dbc 1987/* Convert expression ARG to type TYPE. Used by the middle-end for
1988 simple conversions in preference to calling the front-end's convert. */
1989
d7aeca92 1990tree
b30e3dbc 1991fold_convert (tree type, tree arg)
1992{
1993 tree orig = TREE_TYPE (arg);
1994 tree tem;
1995
1996 if (type == orig)
1997 return arg;
1998
1999 if (TREE_CODE (arg) == ERROR_MARK
2000 || TREE_CODE (type) == ERROR_MARK
2001 || TREE_CODE (orig) == ERROR_MARK)
2002 return error_mark_node;
2003
88e62366 2004 if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (orig)
2005 || lang_hooks.types_compatible_p (TYPE_MAIN_VARIANT (type),
2006 TYPE_MAIN_VARIANT (orig)))
7ab7fd4f 2007 return fold_build1 (NOP_EXPR, type, arg);
b30e3dbc 2008
fdada98f 2009 switch (TREE_CODE (type))
b30e3dbc 2010 {
63bf54cf 2011 case INTEGER_TYPE: case ENUMERAL_TYPE: case BOOLEAN_TYPE:
fdada98f 2012 case POINTER_TYPE: case REFERENCE_TYPE:
2013 case OFFSET_TYPE:
b30e3dbc 2014 if (TREE_CODE (arg) == INTEGER_CST)
2015 {
2016 tem = fold_convert_const (NOP_EXPR, type, arg);
2017 if (tem != NULL_TREE)
2018 return tem;
2019 }
8d4b8f86 2020 if (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2021 || TREE_CODE (orig) == OFFSET_TYPE)
7ab7fd4f 2022 return fold_build1 (NOP_EXPR, type, arg);
b30e3dbc 2023 if (TREE_CODE (orig) == COMPLEX_TYPE)
2024 {
7ab7fd4f 2025 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
b30e3dbc 2026 return fold_convert (type, tem);
2027 }
fdada98f 2028 gcc_assert (TREE_CODE (orig) == VECTOR_TYPE
2029 && tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
7ab7fd4f 2030 return fold_build1 (NOP_EXPR, type, arg);
0c5713a2 2031
fdada98f 2032 case REAL_TYPE:
b30e3dbc 2033 if (TREE_CODE (arg) == INTEGER_CST)
2034 {
2035 tem = fold_convert_const (FLOAT_EXPR, type, arg);
2036 if (tem != NULL_TREE)
2037 return tem;
2038 }
2039 else if (TREE_CODE (arg) == REAL_CST)
2040 {
2041 tem = fold_convert_const (NOP_EXPR, type, arg);
2042 if (tem != NULL_TREE)
2043 return tem;
2044 }
2045
fdada98f 2046 switch (TREE_CODE (orig))
b30e3dbc 2047 {
63bf54cf 2048 case INTEGER_TYPE:
fdada98f 2049 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2050 case POINTER_TYPE: case REFERENCE_TYPE:
7ab7fd4f 2051 return fold_build1 (FLOAT_EXPR, type, arg);
0c5713a2 2052
fdada98f 2053 case REAL_TYPE:
1917f1d7 2054 return fold_build1 (NOP_EXPR, type, arg);
0c5713a2 2055
fdada98f 2056 case COMPLEX_TYPE:
7ab7fd4f 2057 tem = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
b30e3dbc 2058 return fold_convert (type, tem);
0c5713a2 2059
fdada98f 2060 default:
2061 gcc_unreachable ();
b30e3dbc 2062 }
0c5713a2 2063
fdada98f 2064 case COMPLEX_TYPE:
2065 switch (TREE_CODE (orig))
2066 {
63bf54cf 2067 case INTEGER_TYPE:
fdada98f 2068 case BOOLEAN_TYPE: case ENUMERAL_TYPE:
2069 case POINTER_TYPE: case REFERENCE_TYPE:
2070 case REAL_TYPE:
2071 return build2 (COMPLEX_EXPR, type,
2072 fold_convert (TREE_TYPE (type), arg),
2073 fold_convert (TREE_TYPE (type), integer_zero_node));
2074 case COMPLEX_TYPE:
2075 {
2076 tree rpart, ipart;
0c5713a2 2077
fdada98f 2078 if (TREE_CODE (arg) == COMPLEX_EXPR)
2079 {
2080 rpart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 0));
2081 ipart = fold_convert (TREE_TYPE (type), TREE_OPERAND (arg, 1));
7ab7fd4f 2082 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
fdada98f 2083 }
0c5713a2 2084
fdada98f 2085 arg = save_expr (arg);
7ab7fd4f 2086 rpart = fold_build1 (REALPART_EXPR, TREE_TYPE (orig), arg);
2087 ipart = fold_build1 (IMAGPART_EXPR, TREE_TYPE (orig), arg);
fdada98f 2088 rpart = fold_convert (TREE_TYPE (type), rpart);
2089 ipart = fold_convert (TREE_TYPE (type), ipart);
7ab7fd4f 2090 return fold_build2 (COMPLEX_EXPR, type, rpart, ipart);
fdada98f 2091 }
0c5713a2 2092
fdada98f 2093 default:
2094 gcc_unreachable ();
2095 }
0c5713a2 2096
fdada98f 2097 case VECTOR_TYPE:
80db63ef 2098 if (integer_zerop (arg))
2099 return build_zero_vector (type);
fdada98f 2100 gcc_assert (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (orig)));
2101 gcc_assert (INTEGRAL_TYPE_P (orig) || POINTER_TYPE_P (orig)
2102 || TREE_CODE (orig) == VECTOR_TYPE);
a0bfd1b9 2103 return fold_build1 (VIEW_CONVERT_EXPR, type, arg);
b30e3dbc 2104
fdada98f 2105 case VOID_TYPE:
1917f1d7 2106 return fold_build1 (NOP_EXPR, type, fold_ignored_result (arg));
b30e3dbc 2107
fdada98f 2108 default:
2109 gcc_unreachable ();
b30e3dbc 2110 }
b30e3dbc 2111}
2bc77e10 2112\f
77aa6362 2113/* Return false if expr can be assumed not to be an lvalue, true
98fc7ffa 2114 otherwise. */
2bc77e10 2115
98fc7ffa 2116static bool
2117maybe_lvalue_p (tree x)
2bc77e10 2118{
f4d47aeb 2119 /* We only need to wrap lvalue tree codes. */
2120 switch (TREE_CODE (x))
2121 {
2122 case VAR_DECL:
2123 case PARM_DECL:
2124 case RESULT_DECL:
2125 case LABEL_DECL:
2126 case FUNCTION_DECL:
2127 case SSA_NAME:
2128
2129 case COMPONENT_REF:
2130 case INDIRECT_REF:
b056d812 2131 case ALIGN_INDIRECT_REF:
2132 case MISALIGNED_INDIRECT_REF:
f4d47aeb 2133 case ARRAY_REF:
6374121b 2134 case ARRAY_RANGE_REF:
f4d47aeb 2135 case BIT_FIELD_REF:
215e2f1d 2136 case OBJ_TYPE_REF:
f4d47aeb 2137
2138 case REALPART_EXPR:
2139 case IMAGPART_EXPR:
2140 case PREINCREMENT_EXPR:
2141 case PREDECREMENT_EXPR:
2142 case SAVE_EXPR:
f4d47aeb 2143 case TRY_CATCH_EXPR:
2144 case WITH_CLEANUP_EXPR:
2145 case COMPOUND_EXPR:
2146 case MODIFY_EXPR:
2147 case TARGET_EXPR:
2148 case COND_EXPR:
2149 case BIND_EXPR:
2150 case MIN_EXPR:
2151 case MAX_EXPR:
f4d47aeb 2152 break;
2153
2154 default:
2155 /* Assume the worst for front-end tree codes. */
2156 if ((int)TREE_CODE (x) >= NUM_TREE_CODES)
2157 break;
98fc7ffa 2158 return false;
f4d47aeb 2159 }
98fc7ffa 2160
2161 return true;
2162}
2163
2164/* Return an expr equal to X but certainly not valid as an lvalue. */
2165
2166tree
2167non_lvalue (tree x)
2168{
2169 /* While we are in GIMPLE, NON_LVALUE_EXPR doesn't mean anything to
2170 us. */
2171 if (in_gimple_form)
2172 return x;
2173
2174 if (! maybe_lvalue_p (x))
2175 return x;
4ee9c684 2176 return build1 (NON_LVALUE_EXPR, TREE_TYPE (x), x);
2bc77e10 2177}
56753054 2178
b12c26dc 2179/* Nonzero means lvalues are limited to those valid in pedantic ANSI C.
2180 Zero means allow extended lvalues. */
2181
2182int pedantic_lvalues;
2183
56753054 2184/* When pedantic, return an expr equal to X but certainly not valid as a
2185 pedantic lvalue. Otherwise, return X. */
2186
d50efa49 2187static tree
de1b648b 2188pedantic_non_lvalue (tree x)
56753054 2189{
b12c26dc 2190 if (pedantic_lvalues)
56753054 2191 return non_lvalue (x);
2192 else
2193 return x;
2194}
e233264a 2195\f
2196/* Given a tree comparison code, return the code that is the logical inverse
2197 of the given code. It is not safe to do this for floating-point
318a728f 2198 comparisons, except for NE_EXPR and EQ_EXPR, so we receive a machine mode
2199 as well: if reversing the comparison is unsafe, return ERROR_MARK. */
2bc77e10 2200
eea12c72 2201enum tree_code
318a728f 2202invert_tree_comparison (enum tree_code code, bool honor_nans)
e233264a 2203{
318a728f 2204 if (honor_nans && flag_trapping_math)
2205 return ERROR_MARK;
2206
e233264a 2207 switch (code)
2208 {
2209 case EQ_EXPR:
2210 return NE_EXPR;
2211 case NE_EXPR:
2212 return EQ_EXPR;
2213 case GT_EXPR:
318a728f 2214 return honor_nans ? UNLE_EXPR : LE_EXPR;
e233264a 2215 case GE_EXPR:
318a728f 2216 return honor_nans ? UNLT_EXPR : LT_EXPR;
e233264a 2217 case LT_EXPR:
318a728f 2218 return honor_nans ? UNGE_EXPR : GE_EXPR;
e233264a 2219 case LE_EXPR:
318a728f 2220 return honor_nans ? UNGT_EXPR : GT_EXPR;
2221 case LTGT_EXPR:
2222 return UNEQ_EXPR;
2223 case UNEQ_EXPR:
2224 return LTGT_EXPR;
2225 case UNGT_EXPR:
2226 return LE_EXPR;
2227 case UNGE_EXPR:
2228 return LT_EXPR;
2229 case UNLT_EXPR:
2230 return GE_EXPR;
2231 case UNLE_EXPR:
e233264a 2232 return GT_EXPR;
318a728f 2233 case ORDERED_EXPR:
2234 return UNORDERED_EXPR;
2235 case UNORDERED_EXPR:
2236 return ORDERED_EXPR;
e233264a 2237 default:
fdada98f 2238 gcc_unreachable ();
e233264a 2239 }
2240}
2241
2242/* Similar, but return the comparison that results if the operands are
2243 swapped. This is safe for floating-point. */
2244
cc0bdf91 2245enum tree_code
de1b648b 2246swap_tree_comparison (enum tree_code code)
e233264a 2247{
2248 switch (code)
2249 {
2250 case EQ_EXPR:
2251 case NE_EXPR:
6a0aeeaa 2252 case ORDERED_EXPR:
2253 case UNORDERED_EXPR:
2254 case LTGT_EXPR:
2255 case UNEQ_EXPR:
e233264a 2256 return code;
2257 case GT_EXPR:
2258 return LT_EXPR;
2259 case GE_EXPR:
2260 return LE_EXPR;
2261 case LT_EXPR:
2262 return GT_EXPR;
2263 case LE_EXPR:
2264 return GE_EXPR;
6a0aeeaa 2265 case UNGT_EXPR:
2266 return UNLT_EXPR;
2267 case UNGE_EXPR:
2268 return UNLE_EXPR;
2269 case UNLT_EXPR:
2270 return UNGT_EXPR;
2271 case UNLE_EXPR:
2272 return UNGE_EXPR;
e233264a 2273 default:
fdada98f 2274 gcc_unreachable ();
e233264a 2275 }
2276}
8b94828f 2277
7835f163 2278
2279/* Convert a comparison tree code from an enum tree_code representation
2280 into a compcode bit-based encoding. This function is the inverse of
2281 compcode_to_comparison. */
2282
318a728f 2283static enum comparison_code
de1b648b 2284comparison_to_compcode (enum tree_code code)
7835f163 2285{
2286 switch (code)
2287 {
2288 case LT_EXPR:
2289 return COMPCODE_LT;
2290 case EQ_EXPR:
2291 return COMPCODE_EQ;
2292 case LE_EXPR:
2293 return COMPCODE_LE;
2294 case GT_EXPR:
2295 return COMPCODE_GT;
2296 case NE_EXPR:
2297 return COMPCODE_NE;
2298 case GE_EXPR:
2299 return COMPCODE_GE;
318a728f 2300 case ORDERED_EXPR:
2301 return COMPCODE_ORD;
2302 case UNORDERED_EXPR:
2303 return COMPCODE_UNORD;
2304 case UNLT_EXPR:
2305 return COMPCODE_UNLT;
2306 case UNEQ_EXPR:
2307 return COMPCODE_UNEQ;
2308 case UNLE_EXPR:
2309 return COMPCODE_UNLE;
2310 case UNGT_EXPR:
2311 return COMPCODE_UNGT;
2312 case LTGT_EXPR:
2313 return COMPCODE_LTGT;
2314 case UNGE_EXPR:
2315 return COMPCODE_UNGE;
7835f163 2316 default:
fdada98f 2317 gcc_unreachable ();
7835f163 2318 }
2319}
2320
2321/* Convert a compcode bit-based encoding of a comparison operator back
2322 to GCC's enum tree_code representation. This function is the
2323 inverse of comparison_to_compcode. */
2324
2325static enum tree_code
318a728f 2326compcode_to_comparison (enum comparison_code code)
7835f163 2327{
2328 switch (code)
2329 {
2330 case COMPCODE_LT:
2331 return LT_EXPR;
2332 case COMPCODE_EQ:
2333 return EQ_EXPR;
2334 case COMPCODE_LE:
2335 return LE_EXPR;
2336 case COMPCODE_GT:
2337 return GT_EXPR;
2338 case COMPCODE_NE:
2339 return NE_EXPR;
2340 case COMPCODE_GE:
2341 return GE_EXPR;
318a728f 2342 case COMPCODE_ORD:
2343 return ORDERED_EXPR;
2344 case COMPCODE_UNORD:
2345 return UNORDERED_EXPR;
2346 case COMPCODE_UNLT:
2347 return UNLT_EXPR;
2348 case COMPCODE_UNEQ:
2349 return UNEQ_EXPR;
2350 case COMPCODE_UNLE:
2351 return UNLE_EXPR;
2352 case COMPCODE_UNGT:
2353 return UNGT_EXPR;
2354 case COMPCODE_LTGT:
2355 return LTGT_EXPR;
2356 case COMPCODE_UNGE:
2357 return UNGE_EXPR;
7835f163 2358 default:
fdada98f 2359 gcc_unreachable ();
7835f163 2360 }
2361}
2362
318a728f 2363/* Return a tree for the comparison which is the combination of
2364 doing the AND or OR (depending on CODE) of the two operations LCODE
2365 and RCODE on the identical operands LL_ARG and LR_ARG. Take into account
2366 the possibility of trapping if the mode has NaNs, and return NULL_TREE
2367 if this makes the transformation invalid. */
2368
2369tree
2370combine_comparisons (enum tree_code code, enum tree_code lcode,
2371 enum tree_code rcode, tree truth_type,
2372 tree ll_arg, tree lr_arg)
2373{
2374 bool honor_nans = HONOR_NANS (TYPE_MODE (TREE_TYPE (ll_arg)));
2375 enum comparison_code lcompcode = comparison_to_compcode (lcode);
2376 enum comparison_code rcompcode = comparison_to_compcode (rcode);
2377 enum comparison_code compcode;
2378
2379 switch (code)
2380 {
2381 case TRUTH_AND_EXPR: case TRUTH_ANDIF_EXPR:
2382 compcode = lcompcode & rcompcode;
2383 break;
2384
2385 case TRUTH_OR_EXPR: case TRUTH_ORIF_EXPR:
2386 compcode = lcompcode | rcompcode;
2387 break;
2388
2389 default:
2390 return NULL_TREE;
2391 }
2392
2393 if (!honor_nans)
2394 {
2395 /* Eliminate unordered comparisons, as well as LTGT and ORD
2396 which are not used unless the mode has NaNs. */
2397 compcode &= ~COMPCODE_UNORD;
2398 if (compcode == COMPCODE_LTGT)
2399 compcode = COMPCODE_NE;
2400 else if (compcode == COMPCODE_ORD)
2401 compcode = COMPCODE_TRUE;
2402 }
2403 else if (flag_trapping_math)
2404 {
7206da1b 2405 /* Check that the original operation and the optimized ones will trap
318a728f 2406 under the same condition. */
2407 bool ltrap = (lcompcode & COMPCODE_UNORD) == 0
2408 && (lcompcode != COMPCODE_EQ)
2409 && (lcompcode != COMPCODE_ORD);
2410 bool rtrap = (rcompcode & COMPCODE_UNORD) == 0
2411 && (rcompcode != COMPCODE_EQ)
2412 && (rcompcode != COMPCODE_ORD);
2413 bool trap = (compcode & COMPCODE_UNORD) == 0
2414 && (compcode != COMPCODE_EQ)
2415 && (compcode != COMPCODE_ORD);
2416
2417 /* In a short-circuited boolean expression the LHS might be
2418 such that the RHS, if evaluated, will never trap. For
2419 example, in ORD (x, y) && (x < y), we evaluate the RHS only
2420 if neither x nor y is NaN. (This is a mixed blessing: for
2421 example, the expression above will never trap, hence
2422 optimizing it to x < y would be invalid). */
2423 if ((code == TRUTH_ORIF_EXPR && (lcompcode & COMPCODE_UNORD))
2424 || (code == TRUTH_ANDIF_EXPR && !(lcompcode & COMPCODE_UNORD)))
2425 rtrap = false;
2426
2427 /* If the comparison was short-circuited, and only the RHS
2428 trapped, we may now generate a spurious trap. */
2429 if (rtrap && !ltrap
2430 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
2431 return NULL_TREE;
2432
2433 /* If we changed the conditions that cause a trap, we lose. */
2434 if ((ltrap || rtrap) != trap)
2435 return NULL_TREE;
2436 }
2437
2438 if (compcode == COMPCODE_TRUE)
20783f07 2439 return constant_boolean_node (true, truth_type);
318a728f 2440 else if (compcode == COMPCODE_FALSE)
20783f07 2441 return constant_boolean_node (false, truth_type);
318a728f 2442 else
7ab7fd4f 2443 return fold_build2 (compcode_to_comparison (compcode),
2444 truth_type, ll_arg, lr_arg);
318a728f 2445}
2446
8b94828f 2447/* Return nonzero if CODE is a tree code that represents a truth value. */
2448
2449static int
de1b648b 2450truth_value_p (enum tree_code code)
8b94828f 2451{
ce45a448 2452 return (TREE_CODE_CLASS (code) == tcc_comparison
8b94828f 2453 || code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR
2454 || code == TRUTH_OR_EXPR || code == TRUTH_ORIF_EXPR
2455 || code == TRUTH_XOR_EXPR || code == TRUTH_NOT_EXPR);
2456}
e233264a 2457\f
9e6f4cc9 2458/* Return nonzero if two operands (typically of the same tree node)
2459 are necessarily equal. If either argument has side-effects this
365db11e 2460 function returns zero. FLAGS modifies behavior as follows:
9e6f4cc9 2461
4ee9c684 2462 If OEP_ONLY_CONST is set, only return nonzero for constants.
11acc1df 2463 This function tests whether the operands are indistinguishable;
2464 it does not test whether they are equal using C's == operation.
2465 The distinction is important for IEEE floating point, because
2466 (1) -0.0 and 0.0 are distinguishable, but -0.0==0.0, and
9e6f4cc9 2467 (2) two NaNs may be indistinguishable, but NaN!=NaN.
2468
4ee9c684 2469 If OEP_ONLY_CONST is unset, a VAR_DECL is considered equal to itself
9e6f4cc9 2470 even though it may hold multiple values during a function.
2471 This is because a GCC tree node guarantees that nothing else is
2472 executed between the evaluation of its "operands" (which may often
2473 be evaluated in arbitrary order). Hence if the operands themselves
2474 don't side-effect, the VAR_DECLs, PARM_DECLs etc... must hold the
9b931277 2475 same value in each operand/subexpression. Hence leaving OEP_ONLY_CONST
2476 unset means assuming isochronic (or instantaneous) tree equivalence.
2477 Unless comparing arbitrary expression trees, such as from different
2478 statements, this flag can usually be left unset.
4ee9c684 2479
2480 If OEP_PURE_SAME is set, then pure functions with identical arguments
2481 are considered the same. It is used when the caller has other ways
2482 to ensure that global memory is unchanged in between. */
2bc77e10 2483
2484int
4ee9c684 2485operand_equal_p (tree arg0, tree arg1, unsigned int flags)
2bc77e10 2486{
78a8ed03 2487 /* If either is ERROR_MARK, they aren't equal. */
fa31fec1 2488 if (TREE_CODE (arg0) == ERROR_MARK || TREE_CODE (arg1) == ERROR_MARK)
78a8ed03 2489 return 0;
2490
2bc77e10 2491 /* If both types don't have the same signedness, then we can't consider
2492 them equal. We must check this before the STRIP_NOPS calls
2493 because they may change the signedness of the arguments. */
78a8ed03 2494 if (TYPE_UNSIGNED (TREE_TYPE (arg0)) != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2bc77e10 2495 return 0;
2496
68826b15 2497 /* If both types don't have the same precision, then it is not safe
2498 to strip NOPs. */
2499 if (TYPE_PRECISION (TREE_TYPE (arg0)) != TYPE_PRECISION (TREE_TYPE (arg1)))
2500 return 0;
2501
2bc77e10 2502 STRIP_NOPS (arg0);
2503 STRIP_NOPS (arg1);
2504
ffb99bfe 2505 /* In case both args are comparisons but with different comparison
2506 code, try to swap the comparison operands of one arg to produce
2507 a match and compare that variant. */
2508 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2509 && COMPARISON_CLASS_P (arg0)
2510 && COMPARISON_CLASS_P (arg1))
2511 {
2512 enum tree_code swap_code = swap_tree_comparison (TREE_CODE (arg1));
2513
2514 if (TREE_CODE (arg0) == swap_code)
2515 return operand_equal_p (TREE_OPERAND (arg0, 0),
2516 TREE_OPERAND (arg1, 1), flags)
2517 && operand_equal_p (TREE_OPERAND (arg0, 1),
2518 TREE_OPERAND (arg1, 0), flags);
2519 }
2520
8faaadf1 2521 if (TREE_CODE (arg0) != TREE_CODE (arg1)
2522 /* This is needed for conversions and for COMPONENT_REF.
2523 Might as well play it safe and always test this. */
6a4737bf 2524 || TREE_CODE (TREE_TYPE (arg0)) == ERROR_MARK
2525 || TREE_CODE (TREE_TYPE (arg1)) == ERROR_MARK
8faaadf1 2526 || TYPE_MODE (TREE_TYPE (arg0)) != TYPE_MODE (TREE_TYPE (arg1)))
2bc77e10 2527 return 0;
2528
8faaadf1 2529 /* If ARG0 and ARG1 are the same SAVE_EXPR, they are necessarily equal.
2530 We don't care about side effects in that case because the SAVE_EXPR
2531 takes care of that for us. In all other cases, two expressions are
2532 equal if they have no side effects. If we have two identical
2533 expressions with side effects that should be treated the same due
2534 to the only side effects being identical SAVE_EXPR's, that will
2535 be detected in the recursive calls below. */
4ee9c684 2536 if (arg0 == arg1 && ! (flags & OEP_ONLY_CONST)
8faaadf1 2537 && (TREE_CODE (arg0) == SAVE_EXPR
2538 || (! TREE_SIDE_EFFECTS (arg0) && ! TREE_SIDE_EFFECTS (arg1))))
2bc77e10 2539 return 1;
2540
8faaadf1 2541 /* Next handle constant cases, those for which we can return 1 even
2542 if ONLY_CONST is set. */
2543 if (TREE_CONSTANT (arg0) && TREE_CONSTANT (arg1))
2544 switch (TREE_CODE (arg0))
2545 {
2546 case INTEGER_CST:
d3041b98 2547 return (! TREE_CONSTANT_OVERFLOW (arg0)
2548 && ! TREE_CONSTANT_OVERFLOW (arg1)
a0c2c45b 2549 && tree_int_cst_equal (arg0, arg1));
8faaadf1 2550
2551 case REAL_CST:
d3041b98 2552 return (! TREE_CONSTANT_OVERFLOW (arg0)
2553 && ! TREE_CONSTANT_OVERFLOW (arg1)
62aa7862 2554 && REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
2555 TREE_REAL_CST (arg1)));
8faaadf1 2556
886cfd4f 2557 case VECTOR_CST:
2558 {
2559 tree v1, v2;
2560
2561 if (TREE_CONSTANT_OVERFLOW (arg0)
2562 || TREE_CONSTANT_OVERFLOW (arg1))
2563 return 0;
2564
2565 v1 = TREE_VECTOR_CST_ELTS (arg0);
2566 v2 = TREE_VECTOR_CST_ELTS (arg1);
2567 while (v1 && v2)
2568 {
11cb6006 2569 if (!operand_equal_p (TREE_VALUE (v1), TREE_VALUE (v2),
4ee9c684 2570 flags))
886cfd4f 2571 return 0;
2572 v1 = TREE_CHAIN (v1);
2573 v2 = TREE_CHAIN (v2);
2574 }
2575
6349b545 2576 return v1 == v2;
886cfd4f 2577 }
2578
8faaadf1 2579 case COMPLEX_CST:
2580 return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
4ee9c684 2581 flags)
8faaadf1 2582 && operand_equal_p (TREE_IMAGPART (arg0), TREE_IMAGPART (arg1),
4ee9c684 2583 flags));
8faaadf1 2584
2585 case STRING_CST:
2586 return (TREE_STRING_LENGTH (arg0) == TREE_STRING_LENGTH (arg1)
6b918462 2587 && ! memcmp (TREE_STRING_POINTER (arg0),
8faaadf1 2588 TREE_STRING_POINTER (arg1),
2589 TREE_STRING_LENGTH (arg0)));
2590
2591 case ADDR_EXPR:
2592 return operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0),
2593 0);
0dbd1c74 2594 default:
2595 break;
8faaadf1 2596 }
2bc77e10 2597
4ee9c684 2598 if (flags & OEP_ONLY_CONST)
2bc77e10 2599 return 0;
2600
66bab57a 2601/* Define macros to test an operand from arg0 and arg1 for equality and a
fa31fec1 2602 variant that allows null and views null as being different from any
2603 non-null value. In the latter case, if either is null, the both
2604 must be; otherwise, do the normal comparison. */
2605#define OP_SAME(N) operand_equal_p (TREE_OPERAND (arg0, N), \
2606 TREE_OPERAND (arg1, N), flags)
2607
2608#define OP_SAME_WITH_NULL(N) \
2609 ((!TREE_OPERAND (arg0, N) || !TREE_OPERAND (arg1, N)) \
2610 ? TREE_OPERAND (arg0, N) == TREE_OPERAND (arg1, N) : OP_SAME (N))
2611
2bc77e10 2612 switch (TREE_CODE_CLASS (TREE_CODE (arg0)))
2613 {
ce45a448 2614 case tcc_unary:
2bc77e10 2615 /* Two conversions are equal only if signedness and modes match. */
e6546627 2616 switch (TREE_CODE (arg0))
2617 {
2618 case NOP_EXPR:
2619 case CONVERT_EXPR:
2620 case FIX_CEIL_EXPR:
2621 case FIX_TRUNC_EXPR:
2622 case FIX_FLOOR_EXPR:
2623 case FIX_ROUND_EXPR:
2624 if (TYPE_UNSIGNED (TREE_TYPE (arg0))
2625 != TYPE_UNSIGNED (TREE_TYPE (arg1)))
2626 return 0;
2627 break;
2628 default:
2629 break;
2630 }
2bc77e10 2631
fa31fec1 2632 return OP_SAME (0);
2633
2bc77e10 2634
ce45a448 2635 case tcc_comparison:
2636 case tcc_binary:
fa31fec1 2637 if (OP_SAME (0) && OP_SAME (1))
8faaadf1 2638 return 1;
2639
2640 /* For commutative ops, allow the other order. */
21dff555 2641 return (commutative_tree_code (TREE_CODE (arg0))
8faaadf1 2642 && operand_equal_p (TREE_OPERAND (arg0, 0),
4ee9c684 2643 TREE_OPERAND (arg1, 1), flags)
2bc77e10 2644 && operand_equal_p (TREE_OPERAND (arg0, 1),
4ee9c684 2645 TREE_OPERAND (arg1, 0), flags));
2bc77e10 2646
ce45a448 2647 case tcc_reference:
06506f5d 2648 /* If either of the pointer (or reference) expressions we are
2649 dereferencing contain a side effect, these cannot be equal. */
dbc71562 2650 if (TREE_SIDE_EFFECTS (arg0)
2651 || TREE_SIDE_EFFECTS (arg1))
2652 return 0;
2653
2bc77e10 2654 switch (TREE_CODE (arg0))
2655 {
2656 case INDIRECT_REF:
b056d812 2657 case ALIGN_INDIRECT_REF:
2658 case MISALIGNED_INDIRECT_REF:
b25de375 2659 case REALPART_EXPR:
2660 case IMAGPART_EXPR:
fa31fec1 2661 return OP_SAME (0);
2bc77e10 2662
2bc77e10 2663 case ARRAY_REF:
ba04d9d5 2664 case ARRAY_RANGE_REF:
fa31fec1 2665 /* Operands 2 and 3 may be null. */
2666 return (OP_SAME (0)
2667 && OP_SAME (1)
2668 && OP_SAME_WITH_NULL (2)
2669 && OP_SAME_WITH_NULL (3));
6ab43650 2670
2671 case COMPONENT_REF:
2f16183e 2672 /* Handle operand 2 the same as for ARRAY_REF. Operand 0
2673 may be NULL when we're called to compare MEM_EXPRs. */
2674 return OP_SAME_WITH_NULL (0)
2675 && OP_SAME (1)
2676 && OP_SAME_WITH_NULL (2);
8d061c60 2677
e715d92e 2678 case BIT_FIELD_REF:
fa31fec1 2679 return OP_SAME (0) && OP_SAME (1) && OP_SAME (2);
2680
0dbd1c74 2681 default:
2682 return 0;
2bc77e10 2683 }
1d322a97 2684
ce45a448 2685 case tcc_expression:
564989a5 2686 switch (TREE_CODE (arg0))
2687 {
2688 case ADDR_EXPR:
2689 case TRUTH_NOT_EXPR:
fa31fec1 2690 return OP_SAME (0);
564989a5 2691
bd975dc2 2692 case TRUTH_ANDIF_EXPR:
2693 case TRUTH_ORIF_EXPR:
fa31fec1 2694 return OP_SAME (0) && OP_SAME (1);
bd975dc2 2695
2696 case TRUTH_AND_EXPR:
2697 case TRUTH_OR_EXPR:
2698 case TRUTH_XOR_EXPR:
fa31fec1 2699 if (OP_SAME (0) && OP_SAME (1))
2700 return 1;
2701
2702 /* Otherwise take into account this is a commutative operation. */
bd975dc2 2703 return (operand_equal_p (TREE_OPERAND (arg0, 0),
fa31fec1 2704 TREE_OPERAND (arg1, 1), flags)
bd975dc2 2705 && operand_equal_p (TREE_OPERAND (arg0, 1),
fa31fec1 2706 TREE_OPERAND (arg1, 0), flags));
bd975dc2 2707
06506f5d 2708 case CALL_EXPR:
2709 /* If the CALL_EXPRs call different functions, then they
2710 clearly can not be equal. */
fa31fec1 2711 if (!OP_SAME (0))
06506f5d 2712 return 0;
2713
4ee9c684 2714 {
2715 unsigned int cef = call_expr_flags (arg0);
2716 if (flags & OEP_PURE_SAME)
2717 cef &= ECF_CONST | ECF_PURE;
2718 else
2719 cef &= ECF_CONST;
2720 if (!cef)
2721 return 0;
2722 }
06506f5d 2723
2724 /* Now see if all the arguments are the same. operand_equal_p
2725 does not handle TREE_LIST, so we walk the operands here
2726 feeding them to operand_equal_p. */
2727 arg0 = TREE_OPERAND (arg0, 1);
2728 arg1 = TREE_OPERAND (arg1, 1);
2729 while (arg0 && arg1)
2730 {
4ee9c684 2731 if (! operand_equal_p (TREE_VALUE (arg0), TREE_VALUE (arg1),
2732 flags))
06506f5d 2733 return 0;
2734
2735 arg0 = TREE_CHAIN (arg0);
2736 arg1 = TREE_CHAIN (arg1);
2737 }
2738
2739 /* If we get here and both argument lists are exhausted
2740 then the CALL_EXPRs are equal. */
2741 return ! (arg0 || arg1);
2742
564989a5 2743 default:
2744 return 0;
2745 }
cc049fa3 2746
ce45a448 2747 case tcc_declaration:
4ee9c684 2748 /* Consider __builtin_sqrt equal to sqrt. */
2749 return (TREE_CODE (arg0) == FUNCTION_DECL
2750 && DECL_BUILT_IN (arg0) && DECL_BUILT_IN (arg1)
2751 && DECL_BUILT_IN_CLASS (arg0) == DECL_BUILT_IN_CLASS (arg1)
2752 && DECL_FUNCTION_CODE (arg0) == DECL_FUNCTION_CODE (arg1));
06506f5d 2753
0dbd1c74 2754 default:
2755 return 0;
2bc77e10 2756 }
fa31fec1 2757
2758#undef OP_SAME
2759#undef OP_SAME_WITH_NULL
2bc77e10 2760}
e233264a 2761\f
2762/* Similar to operand_equal_p, but see if ARG0 might have been made by
cc049fa3 2763 shorten_compare from ARG1 when ARG1 was being compared with OTHER.
2bc77e10 2764
2bc77e10 2765 When in doubt, return 0. */
2766
cc049fa3 2767static int
de1b648b 2768operand_equal_for_comparison_p (tree arg0, tree arg1, tree other)
2bc77e10 2769{
e233264a 2770 int unsignedp1, unsignedpo;
df7caa7b 2771 tree primarg0, primarg1, primother;
02e7a332 2772 unsigned int correct_width;
2bc77e10 2773
e233264a 2774 if (operand_equal_p (arg0, arg1, 0))
2bc77e10 2775 return 1;
2776
154e6f12 2777 if (! INTEGRAL_TYPE_P (TREE_TYPE (arg0))
2778 || ! INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
2bc77e10 2779 return 0;
2780
df7caa7b 2781 /* Discard any conversions that don't change the modes of ARG0 and ARG1
2782 and see if the inner values are the same. This removes any
2783 signedness comparison, which doesn't matter here. */
2784 primarg0 = arg0, primarg1 = arg1;
cc049fa3 2785 STRIP_NOPS (primarg0);
2786 STRIP_NOPS (primarg1);
df7caa7b 2787 if (operand_equal_p (primarg0, primarg1, 0))
2788 return 1;
2789
e233264a 2790 /* Duplicate what shorten_compare does to ARG1 and see if that gives the
2791 actual comparison operand, ARG0.
2bc77e10 2792
e233264a 2793 First throw away any conversions to wider types
2bc77e10 2794 already present in the operands. */
2bc77e10 2795
e233264a 2796 primarg1 = get_narrower (arg1, &unsignedp1);
2797 primother = get_narrower (other, &unsignedpo);
2798
2799 correct_width = TYPE_PRECISION (TREE_TYPE (arg1));
2800 if (unsignedp1 == unsignedpo
2801 && TYPE_PRECISION (TREE_TYPE (primarg1)) < correct_width
2802 && TYPE_PRECISION (TREE_TYPE (primother)) < correct_width)
2bc77e10 2803 {
e233264a 2804 tree type = TREE_TYPE (arg0);
2bc77e10 2805
2806 /* Make sure shorter operand is extended the right way
2807 to match the longer operand. */
fa8b888f 2808 primarg1 = fold_convert (lang_hooks.types.signed_or_unsigned_type
b30e3dbc 2809 (unsignedp1, TREE_TYPE (primarg1)), primarg1);
2bc77e10 2810
b30e3dbc 2811 if (operand_equal_p (arg0, fold_convert (type, primarg1), 0))
2bc77e10 2812 return 1;
2813 }
2814
2815 return 0;
2816}
2817\f
eb2f80f3 2818/* See if ARG is an expression that is either a comparison or is performing
e233264a 2819 arithmetic on comparisons. The comparisons must only be comparing
2820 two different values, which will be stored in *CVAL1 and *CVAL2; if
6ef828f9 2821 they are nonzero it means that some operands have already been found.
e233264a 2822 No variables may be used anywhere else in the expression except in the
d0314131 2823 comparisons. If SAVE_P is true it means we removed a SAVE_EXPR around
2824 the expression and save_expr needs to be called with CVAL1 and CVAL2.
e233264a 2825
2826 If this is true, return 1. Otherwise, return zero. */
2827
2828static int
de1b648b 2829twoval_comparison_p (tree arg, tree *cval1, tree *cval2, int *save_p)
e233264a 2830{
2831 enum tree_code code = TREE_CODE (arg);
ce45a448 2832 enum tree_code_class class = TREE_CODE_CLASS (code);
e233264a 2833
ce45a448 2834 /* We can handle some of the tcc_expression cases here. */
2835 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2836 class = tcc_unary;
2837 else if (class == tcc_expression
e233264a 2838 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR
2839 || code == COMPOUND_EXPR))
ce45a448 2840 class = tcc_binary;
8be91fe5 2841
ce45a448 2842 else if (class == tcc_expression && code == SAVE_EXPR
083a2b5e 2843 && ! TREE_SIDE_EFFECTS (TREE_OPERAND (arg, 0)))
d0314131 2844 {
2845 /* If we've already found a CVAL1 or CVAL2, this expression is
2846 two complex to handle. */
2847 if (*cval1 || *cval2)
2848 return 0;
2849
ce45a448 2850 class = tcc_unary;
d0314131 2851 *save_p = 1;
2852 }
e233264a 2853
2854 switch (class)
2855 {
ce45a448 2856 case tcc_unary:
d0314131 2857 return twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p);
e233264a 2858
ce45a448 2859 case tcc_binary:
d0314131 2860 return (twoval_comparison_p (TREE_OPERAND (arg, 0), cval1, cval2, save_p)
2861 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2862 cval1, cval2, save_p));
e233264a 2863
ce45a448 2864 case tcc_constant:
e233264a 2865 return 1;
2866
ce45a448 2867 case tcc_expression:
e233264a 2868 if (code == COND_EXPR)
d0314131 2869 return (twoval_comparison_p (TREE_OPERAND (arg, 0),
2870 cval1, cval2, save_p)
2871 && twoval_comparison_p (TREE_OPERAND (arg, 1),
2872 cval1, cval2, save_p)
e233264a 2873 && twoval_comparison_p (TREE_OPERAND (arg, 2),
d0314131 2874 cval1, cval2, save_p));
e233264a 2875 return 0;
cc049fa3 2876
ce45a448 2877 case tcc_comparison:
e233264a 2878 /* First see if we can handle the first operand, then the second. For
2879 the second operand, we know *CVAL1 can't be zero. It must be that
2880 one side of the comparison is each of the values; test for the
2881 case where this isn't true by failing if the two operands
2882 are the same. */
2883
2884 if (operand_equal_p (TREE_OPERAND (arg, 0),
2885 TREE_OPERAND (arg, 1), 0))
2886 return 0;
2887
2888 if (*cval1 == 0)
2889 *cval1 = TREE_OPERAND (arg, 0);
2890 else if (operand_equal_p (*cval1, TREE_OPERAND (arg, 0), 0))
2891 ;
2892 else if (*cval2 == 0)
2893 *cval2 = TREE_OPERAND (arg, 0);
2894 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 0), 0))
2895 ;
2896 else
2897 return 0;
2898
2899 if (operand_equal_p (*cval1, TREE_OPERAND (arg, 1), 0))
2900 ;
2901 else if (*cval2 == 0)
2902 *cval2 = TREE_OPERAND (arg, 1);
2903 else if (operand_equal_p (*cval2, TREE_OPERAND (arg, 1), 0))
2904 ;
2905 else
2906 return 0;
2907
2908 return 1;
e233264a 2909
0dbd1c74 2910 default:
2911 return 0;
2912 }
e233264a 2913}
2914\f
2915/* ARG is a tree that is known to contain just arithmetic operations and
2916 comparisons. Evaluate the operations in the tree substituting NEW0 for
eb2f80f3 2917 any occurrence of OLD0 as an operand of a comparison and likewise for
e233264a 2918 NEW1 and OLD1. */
2919
2920static tree
de1b648b 2921eval_subst (tree arg, tree old0, tree new0, tree old1, tree new1)
e233264a 2922{
2923 tree type = TREE_TYPE (arg);
2924 enum tree_code code = TREE_CODE (arg);
ce45a448 2925 enum tree_code_class class = TREE_CODE_CLASS (code);
e233264a 2926
ce45a448 2927 /* We can handle some of the tcc_expression cases here. */
2928 if (class == tcc_expression && code == TRUTH_NOT_EXPR)
2929 class = tcc_unary;
2930 else if (class == tcc_expression
e233264a 2931 && (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR))
ce45a448 2932 class = tcc_binary;
e233264a 2933
2934 switch (class)
2935 {
ce45a448 2936 case tcc_unary:
7ab7fd4f 2937 return fold_build1 (code, type,
2938 eval_subst (TREE_OPERAND (arg, 0),
2939 old0, new0, old1, new1));
e233264a 2940
ce45a448 2941 case tcc_binary:
7ab7fd4f 2942 return fold_build2 (code, type,
2943 eval_subst (TREE_OPERAND (arg, 0),
2944 old0, new0, old1, new1),
2945 eval_subst (TREE_OPERAND (arg, 1),
2946 old0, new0, old1, new1));
e233264a 2947
ce45a448 2948 case tcc_expression:
e233264a 2949 switch (code)
2950 {
2951 case SAVE_EXPR:
2952 return eval_subst (TREE_OPERAND (arg, 0), old0, new0, old1, new1);
2953
2954 case COMPOUND_EXPR:
2955 return eval_subst (TREE_OPERAND (arg, 1), old0, new0, old1, new1);
2956
2957 case COND_EXPR:
7ab7fd4f 2958 return fold_build3 (code, type,
2959 eval_subst (TREE_OPERAND (arg, 0),
2960 old0, new0, old1, new1),
2961 eval_subst (TREE_OPERAND (arg, 1),
2962 old0, new0, old1, new1),
2963 eval_subst (TREE_OPERAND (arg, 2),
2964 old0, new0, old1, new1));
0dbd1c74 2965 default:
2966 break;
e233264a 2967 }
b4b174c3 2968 /* Fall through - ??? */
e233264a 2969
ce45a448 2970 case tcc_comparison:
e233264a 2971 {
2972 tree arg0 = TREE_OPERAND (arg, 0);
2973 tree arg1 = TREE_OPERAND (arg, 1);
2974
2975 /* We need to check both for exact equality and tree equality. The
2976 former will be true if the operand has a side-effect. In that
2977 case, we know the operand occurred exactly once. */
2978
2979 if (arg0 == old0 || operand_equal_p (arg0, old0, 0))
2980 arg0 = new0;
2981 else if (arg0 == old1 || operand_equal_p (arg0, old1, 0))
2982 arg0 = new1;
2983
2984 if (arg1 == old0 || operand_equal_p (arg1, old0, 0))
2985 arg1 = new0;
2986 else if (arg1 == old1 || operand_equal_p (arg1, old1, 0))
2987 arg1 = new1;
2988
7ab7fd4f 2989 return fold_build2 (code, type, arg0, arg1);
e233264a 2990 }
e233264a 2991
0dbd1c74 2992 default:
2993 return arg;
2994 }
e233264a 2995}
2996\f
2bc77e10 2997/* Return a tree for the case when the result of an expression is RESULT
2998 converted to TYPE and OMITTED was previously an operand of the expression
2999 but is now not needed (e.g., we folded OMITTED * 0).
3000
3001 If OMITTED has side effects, we must evaluate it. Otherwise, just do
3002 the conversion of RESULT to TYPE. */
3003
e9f80ff5 3004tree
de1b648b 3005omit_one_operand (tree type, tree result, tree omitted)
2bc77e10 3006{
b30e3dbc 3007 tree t = fold_convert (type, result);
2bc77e10 3008
3009 if (TREE_SIDE_EFFECTS (omitted))
db97ad41 3010 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
2bc77e10 3011
c3ce5d04 3012 return non_lvalue (t);
2bc77e10 3013}
6df5edfa 3014
3015/* Similar, but call pedantic_non_lvalue instead of non_lvalue. */
3016
3017static tree
de1b648b 3018pedantic_omit_one_operand (tree type, tree result, tree omitted)
6df5edfa 3019{
b30e3dbc 3020 tree t = fold_convert (type, result);
6df5edfa 3021
3022 if (TREE_SIDE_EFFECTS (omitted))
db97ad41 3023 return build2 (COMPOUND_EXPR, type, fold_ignored_result (omitted), t);
6df5edfa 3024
3025 return pedantic_non_lvalue (t);
3026}
9bc9f15f 3027
3028/* Return a tree for the case when the result of an expression is RESULT
3029 converted to TYPE and OMITTED1 and OMITTED2 were previously operands
3030 of the expression but are now not needed.
3031
3032 If OMITTED1 or OMITTED2 has side effects, they must be evaluated.
3033 If both OMITTED1 and OMITTED2 have side effects, OMITTED1 is
3034 evaluated before OMITTED2. Otherwise, if neither has side effects,
3035 just do the conversion of RESULT to TYPE. */
3036
3037tree
3038omit_two_operands (tree type, tree result, tree omitted1, tree omitted2)
3039{
3040 tree t = fold_convert (type, result);
3041
3042 if (TREE_SIDE_EFFECTS (omitted2))
3043 t = build2 (COMPOUND_EXPR, type, omitted2, t);
3044 if (TREE_SIDE_EFFECTS (omitted1))
3045 t = build2 (COMPOUND_EXPR, type, omitted1, t);
3046
3047 return TREE_CODE (t) != COMPOUND_EXPR ? non_lvalue (t) : t;
3048}
3049
2bc77e10 3050\f
46b0e007 3051/* Return a simplified tree node for the truth-negation of ARG. This
3052 never alters ARG itself. We assume that ARG is an operation that
318a728f 3053 returns a truth value (0 or 1).
2bc77e10 3054
318a728f 3055 FIXME: one would think we would fold the result, but it causes
3056 problems with the dominator optimizer. */
6758b11c 3057
2bc77e10 3058tree
6758b11c 3059fold_truth_not_expr (tree arg)
2bc77e10 3060{
3061 tree type = TREE_TYPE (arg);
e233264a 3062 enum tree_code code = TREE_CODE (arg);
2bc77e10 3063
e233264a 3064 /* If this is a comparison, we can simply invert it, except for
3065 floating-point non-equality comparisons, in which case we just
3066 enclose a TRUTH_NOT_EXPR around what we have. */
2bc77e10 3067
ce45a448 3068 if (TREE_CODE_CLASS (code) == tcc_comparison)
2bc77e10 3069 {
318a728f 3070 tree op_type = TREE_TYPE (TREE_OPERAND (arg, 0));
3071 if (FLOAT_TYPE_P (op_type)
3072 && flag_trapping_math
3073 && code != ORDERED_EXPR && code != UNORDERED_EXPR
3074 && code != NE_EXPR && code != EQ_EXPR)
6758b11c 3075 return NULL_TREE;
e233264a 3076 else
318a728f 3077 {
3078 code = invert_tree_comparison (code,
3079 HONOR_NANS (TYPE_MODE (op_type)));
3080 if (code == ERROR_MARK)
6758b11c 3081 return NULL_TREE;
318a728f 3082 else
3083 return build2 (code, type,
3084 TREE_OPERAND (arg, 0), TREE_OPERAND (arg, 1));
3085 }
e233264a 3086 }
2bc77e10 3087
e233264a 3088 switch (code)
3089 {
2bc77e10 3090 case INTEGER_CST:
b7f352d5 3091 return constant_boolean_node (integer_zerop (arg), type);
2bc77e10 3092
3093 case TRUTH_AND_EXPR:
fd96eeef 3094 return build2 (TRUTH_OR_EXPR, type,
3095 invert_truthvalue (TREE_OPERAND (arg, 0)),
3096 invert_truthvalue (TREE_OPERAND (arg, 1)));
2bc77e10 3097
3098 case TRUTH_OR_EXPR:
fd96eeef 3099 return build2 (TRUTH_AND_EXPR, type,
3100 invert_truthvalue (TREE_OPERAND (arg, 0)),
3101 invert_truthvalue (TREE_OPERAND (arg, 1)));
2bc77e10 3102
9a7b73a1 3103 case TRUTH_XOR_EXPR:
3104 /* Here we can invert either operand. We invert the first operand
3105 unless the second operand is a TRUTH_NOT_EXPR in which case our
3106 result is the XOR of the first operand with the inside of the
3107 negation of the second operand. */
3108
3109 if (TREE_CODE (TREE_OPERAND (arg, 1)) == TRUTH_NOT_EXPR)
fd96eeef 3110 return build2 (TRUTH_XOR_EXPR, type, TREE_OPERAND (arg, 0),
3111 TREE_OPERAND (TREE_OPERAND (arg, 1), 0));
9a7b73a1 3112 else
fd96eeef 3113 return build2 (TRUTH_XOR_EXPR, type,
3114 invert_truthvalue (TREE_OPERAND (arg, 0)),
3115 TREE_OPERAND (arg, 1));
9a7b73a1 3116
2bc77e10 3117 case TRUTH_ANDIF_EXPR:
fd96eeef 3118 return build2 (TRUTH_ORIF_EXPR, type,
3119 invert_truthvalue (TREE_OPERAND (arg, 0)),
3120 invert_truthvalue (TREE_OPERAND (arg, 1)));
2bc77e10 3121
3122 case TRUTH_ORIF_EXPR:
fd96eeef 3123 return build2 (TRUTH_ANDIF_EXPR, type,
3124 invert_truthvalue (TREE_OPERAND (arg, 0)),
3125 invert_truthvalue (TREE_OPERAND (arg, 1)));
2bc77e10 3126
3127 case TRUTH_NOT_EXPR:
3128 return TREE_OPERAND (arg, 0);
3129
3130 case COND_EXPR:
76ce1401 3131 {
3132 tree arg1 = TREE_OPERAND (arg, 1);
3133 tree arg2 = TREE_OPERAND (arg, 2);
3134 /* A COND_EXPR may have a throw as one operand, which
3135 then has void type. Just leave void operands
3136 as they are. */
3137 return build3 (COND_EXPR, type, TREE_OPERAND (arg, 0),
3138 VOID_TYPE_P (TREE_TYPE (arg1))
3139 ? arg1 : invert_truthvalue (arg1),
3140 VOID_TYPE_P (TREE_TYPE (arg2))
3141 ? arg2 : invert_truthvalue (arg2));
3142 }
2bc77e10 3143
3139f3ce 3144 case COMPOUND_EXPR:
fd96eeef 3145 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg, 0),
3146 invert_truthvalue (TREE_OPERAND (arg, 1)));
3139f3ce 3147
2bc77e10 3148 case NON_LVALUE_EXPR:
3149 return invert_truthvalue (TREE_OPERAND (arg, 0));
3150
3151 case NOP_EXPR:
4ee9c684 3152 if (TREE_CODE (TREE_TYPE (arg)) == BOOLEAN_TYPE)
6758b11c 3153 return build1 (TRUTH_NOT_EXPR, type, arg);
4ee9c684 3154
2bc77e10 3155 case CONVERT_EXPR:
3156 case FLOAT_EXPR:
3157 return build1 (TREE_CODE (arg), type,
3158 invert_truthvalue (TREE_OPERAND (arg, 0)));
3159
3160 case BIT_AND_EXPR:
c35387e1 3161 if (!integer_onep (TREE_OPERAND (arg, 1)))
3162 break;
fd96eeef 3163 return build2 (EQ_EXPR, type, arg,
3c6185f1 3164 build_int_cst (type, 0));
2bc77e10 3165
468d693c 3166 case SAVE_EXPR:
3167 return build1 (TRUTH_NOT_EXPR, type, arg);
f33c3a83 3168
3169 case CLEANUP_POINT_EXPR:
3170 return build1 (CLEANUP_POINT_EXPR, type,
3171 invert_truthvalue (TREE_OPERAND (arg, 0)));
0dbd1c74 3172
3173 default:
3174 break;
c35387e1 3175 }
6758b11c 3176
3177 return NULL_TREE;
3178}
3179
3180/* Return a simplified tree node for the truth-negation of ARG. This
3181 never alters ARG itself. We assume that ARG is an operation that
3182 returns a truth value (0 or 1).
3183
3184 FIXME: one would think we would fold the result, but it causes
3185 problems with the dominator optimizer. */
3186
3187tree
3188invert_truthvalue (tree arg)
3189{
3190 tree tem;
3191
3192 if (TREE_CODE (arg) == ERROR_MARK)
3193 return arg;
3194
3195 tem = fold_truth_not_expr (arg);
3196 if (!tem)
3197 tem = build1 (TRUTH_NOT_EXPR, TREE_TYPE (arg), arg);
3198
3199 return tem;
2bc77e10 3200}
3201
3202/* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
3203 operands are another bit-wise operation with a common input. If so,
3204 distribute the bit operations to save an operation and possibly two if
3205 constants are involved. For example, convert
de1b648b 3206 (A | B) & (A | C) into A | (B & C)
2bc77e10 3207 Further simplification will occur if B and C are constants.
3208
3209 If this optimization cannot be done, 0 will be returned. */
3210
3211static tree
de1b648b 3212distribute_bit_expr (enum tree_code code, tree type, tree arg0, tree arg1)
2bc77e10 3213{
3214 tree common;
3215 tree left, right;
3216
3217 if (TREE_CODE (arg0) != TREE_CODE (arg1)
3218 || TREE_CODE (arg0) == code
5b1de181 3219 || (TREE_CODE (arg0) != BIT_AND_EXPR
3220 && TREE_CODE (arg0) != BIT_IOR_EXPR))
2bc77e10 3221 return 0;
3222
3223 if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 0), 0))
3224 {
3225 common = TREE_OPERAND (arg0, 0);
3226 left = TREE_OPERAND (arg0, 1);
3227 right = TREE_OPERAND (arg1, 1);
3228 }
3229 else if (operand_equal_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg1, 1), 0))
3230 {
3231 common = TREE_OPERAND (arg0, 0);
3232 left = TREE_OPERAND (arg0, 1);
3233 right = TREE_OPERAND (arg1, 0);
3234 }
3235 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 0), 0))
3236 {
3237 common = TREE_OPERAND (arg0, 1);
3238 left = TREE_OPERAND (arg0, 0);
3239 right = TREE_OPERAND (arg1, 1);
3240 }
3241 else if (operand_equal_p (TREE_OPERAND (arg0, 1), TREE_OPERAND (arg1, 1), 0))
3242 {
3243 common = TREE_OPERAND (arg0, 1);
3244 left = TREE_OPERAND (arg0, 0);
3245 right = TREE_OPERAND (arg1, 0);
3246 }
3247 else
3248 return 0;
3249
7ab7fd4f 3250 return fold_build2 (TREE_CODE (arg0), type, common,
3251 fold_build2 (code, type, left, right));
2bc77e10 3252}
429f2f90 3253
3254/* Knowing that ARG0 and ARG1 are both RDIV_EXPRs, simplify a binary operation
3255 with code CODE. This optimization is unsafe. */
3256static tree
3257distribute_real_division (enum tree_code code, tree type, tree arg0, tree arg1)
3258{
3259 bool mul0 = TREE_CODE (arg0) == MULT_EXPR;
3260 bool mul1 = TREE_CODE (arg1) == MULT_EXPR;
3261
3262 /* (A / C) +- (B / C) -> (A +- B) / C. */
3263 if (mul0 == mul1
3264 && operand_equal_p (TREE_OPERAND (arg0, 1),
3265 TREE_OPERAND (arg1, 1), 0))
3266 return fold_build2 (mul0 ? MULT_EXPR : RDIV_EXPR, type,
3267 fold_build2 (code, type,
3268 TREE_OPERAND (arg0, 0),
3269 TREE_OPERAND (arg1, 0)),
3270 TREE_OPERAND (arg0, 1));
3271
3272 /* (A / C1) +- (A / C2) -> A * (1 / C1 +- 1 / C2). */
3273 if (operand_equal_p (TREE_OPERAND (arg0, 0),
3274 TREE_OPERAND (arg1, 0), 0)
3275 && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
3276 && TREE_CODE (TREE_OPERAND (arg1, 1)) == REAL_CST)
3277 {
3278 REAL_VALUE_TYPE r0, r1;
3279 r0 = TREE_REAL_CST (TREE_OPERAND (arg0, 1));
3280 r1 = TREE_REAL_CST (TREE_OPERAND (arg1, 1));
3281 if (!mul0)
3282 real_arithmetic (&r0, RDIV_EXPR, &dconst1, &r0);
3283 if (!mul1)
3284 real_arithmetic (&r1, RDIV_EXPR, &dconst1, &r1);
3285 real_arithmetic (&r0, code, &r0, &r1);
3286 return fold_build2 (MULT_EXPR, type,
3287 TREE_OPERAND (arg0, 0),
3288 build_real (type, r0));
3289 }
3290
3291 return NULL_TREE;
3292}
2bc77e10 3293\f
3294/* Return a BIT_FIELD_REF of type TYPE to refer to BITSIZE bits of INNER
6ef828f9 3295 starting at BITPOS. The field is unsigned if UNSIGNEDP is nonzero. */
2bc77e10 3296
3297static tree
dc81944a 3298make_bit_field_ref (tree inner, tree type, int bitsize, int bitpos,
3299 int unsignedp)
2bc77e10 3300{
85453a57 3301 tree result;
3302
3303 if (bitpos == 0)
3304 {
3305 tree size = TYPE_SIZE (TREE_TYPE (inner));
3306 if ((INTEGRAL_TYPE_P (TREE_TYPE (inner))
3307 || POINTER_TYPE_P (TREE_TYPE (inner)))
3308 && host_integerp (size, 0)
3309 && tree_low_cst (size, 0) == bitsize)
3310 return fold_convert (type, inner);
3311 }
3312
3313 result = build3 (BIT_FIELD_REF, type, inner,
3314 size_int (bitsize), bitsize_int (bitpos));
2bc77e10 3315
86ae60fd 3316 BIT_FIELD_REF_UNSIGNED (result) = unsignedp;
2bc77e10 3317
3318 return result;
3319}
3320
3321/* Optimize a bit-field compare.
3322
3323 There are two cases: First is a compare against a constant and the
3324 second is a comparison of two items where the fields are at the same
3325 bit position relative to the start of a chunk (byte, halfword, word)
3326 large enough to contain it. In these cases we can avoid the shift
3327 implicit in bitfield extractions.
3328
3329 For constants, we emit a compare of the shifted constant with the
3330 BIT_AND_EXPR of a mask and a byte, halfword, or word of the operand being
3331 compared. For two fields at the same position, we do the ANDs with the
3332 similar mask and compare the result of the ANDs.
3333
3334 CODE is the comparison code, known to be either NE_EXPR or EQ_EXPR.
3335 COMPARE_TYPE is the type of the comparison, and LHS and RHS
3336 are the left and right operands of the comparison, respectively.
3337
4bbea254 3338 If the optimization described above can be done, we return the resulting
2bc77e10 3339 tree. Otherwise we return zero. */
3340
3341static tree
dc81944a 3342optimize_bit_field_compare (enum tree_code code, tree compare_type,
3343 tree lhs, tree rhs)
2bc77e10 3344{
02e7a332 3345 HOST_WIDE_INT lbitpos, lbitsize, rbitpos, rbitsize, nbitpos, nbitsize;
2bc77e10 3346 tree type = TREE_TYPE (lhs);
3347 tree signed_type, unsigned_type;
3348 int const_p = TREE_CODE (rhs) == INTEGER_CST;
4d1060a2 3349 enum machine_mode lmode, rmode, nmode;
2bc77e10 3350 int lunsignedp, runsignedp;
3351 int lvolatilep = 0, rvolatilep = 0;
93b6a460 3352 tree linner, rinner = NULL_TREE;
2bc77e10 3353 tree mask;
bbfbdece 3354 tree offset;
2bc77e10 3355
3356 /* Get all the information about the extractions being done. If the bit size
3357 if the same as the size of the underlying object, we aren't doing an
155b05dc 3358 extraction at all and so can do nothing. We also don't want to
3359 do anything if the inner expression is a PLACEHOLDER_EXPR since we
3360 then will no longer be able to replace it. */
bbfbdece 3361 linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
e7e9416e 3362 &lunsignedp, &lvolatilep, false);
f73497ef 3363 if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
155b05dc 3364 || offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
2bc77e10 3365 return 0;
3366
3367 if (!const_p)
3368 {
3369 /* If this is not a constant, we can only do something if bit positions,
1e625a2e 3370 sizes, and signedness are the same. */
417d3458 3371 rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
e7e9416e 3372 &runsignedp, &rvolatilep, false);
2bc77e10 3373
f73497ef 3374 if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
155b05dc 3375 || lunsignedp != runsignedp || offset != 0
3376 || TREE_CODE (rinner) == PLACEHOLDER_EXPR)
2bc77e10 3377 return 0;
3378 }
3379
3380 /* See if we can find a mode to refer to this field. We should be able to,
3381 but fail if we can't. */
4d1060a2 3382 nmode = get_best_mode (lbitsize, lbitpos,
3383 const_p ? TYPE_ALIGN (TREE_TYPE (linner))
3384 : MIN (TYPE_ALIGN (TREE_TYPE (linner)),
3385 TYPE_ALIGN (TREE_TYPE (rinner))),
3386 word_mode, lvolatilep || rvolatilep);
3387 if (nmode == VOIDmode)
2bc77e10 3388 return 0;
3389
3390 /* Set signed and unsigned types of the precision of this mode for the
3391 shifts below. */
fa8b888f 3392 signed_type = lang_hooks.types.type_for_mode (nmode, 0);
3393 unsigned_type = lang_hooks.types.type_for_mode (nmode, 1);
2bc77e10 3394
2bc77e10 3395 /* Compute the bit position and size for the new reference and our offset
3396 within it. If the new reference is the same size as the original, we
3397 won't optimize anything, so return zero. */
4d1060a2 3398 nbitsize = GET_MODE_BITSIZE (nmode);
3399 nbitpos = lbitpos & ~ (nbitsize - 1);
3400 lbitpos -= nbitpos;
3401 if (nbitsize == lbitsize)
2bc77e10 3402 return 0;
3403
51356f86 3404 if (BYTES_BIG_ENDIAN)
4d1060a2 3405 lbitpos = nbitsize - lbitsize - lbitpos;
2bc77e10 3406
3407 /* Make the mask to be used against the extracted field. */
7016c612 3408 mask = build_int_cst (unsigned_type, -1);
4d28c5d1 3409 mask = force_fit_type (mask, 0, false, false);
b30e3dbc 3410 mask = fold_convert (unsigned_type, mask);
4d1060a2 3411 mask = const_binop (LSHIFT_EXPR, mask, size_int (nbitsize - lbitsize), 0);
2bc77e10 3412 mask = const_binop (RSHIFT_EXPR, mask,
4d1060a2 3413 size_int (nbitsize - lbitsize - lbitpos), 0);
2bc77e10 3414
3415 if (! const_p)
3416 /* If not comparing with constant, just rework the comparison
3417 and return. */
fd96eeef 3418 return build2 (code, compare_type,
3419 build2 (BIT_AND_EXPR, unsigned_type,
3420 make_bit_field_ref (linner, unsigned_type,
3421 nbitsize, nbitpos, 1),
3422 mask),
3423 build2 (BIT_AND_EXPR, unsigned_type,
3424 make_bit_field_ref (rinner, unsigned_type,
3425 nbitsize, nbitpos, 1),
3426 mask));
2bc77e10 3427
3428 /* Otherwise, we are handling the constant case. See if the constant is too
3429 big for the field. Warn and return a tree of for 0 (false) if so. We do
3430 this not only for its own sake, but to avoid having to test for this
3431 error case below. If we didn't, we might generate wrong code.
3432
3433 For unsigned fields, the constant shifted right by the field length should
cc049fa3 3434 be all zero. For signed fields, the high-order bits should agree with
2bc77e10 3435 the sign bit. */
3436
3437 if (lunsignedp)
3438 {
3439 if (! integer_zerop (const_binop (RSHIFT_EXPR,
b30e3dbc 3440 fold_convert (unsigned_type, rhs),
5485823f 3441 size_int (lbitsize), 0)))
2bc77e10 3442 {
c3ceba8e 3443 warning (0, "comparison is always %d due to width of bit-field",
be2828ce 3444 code == NE_EXPR);
20783f07 3445 return constant_boolean_node (code == NE_EXPR, compare_type);
2bc77e10 3446 }
3447 }
3448 else
3449 {
b30e3dbc 3450 tree tem = const_binop (RSHIFT_EXPR, fold_convert (signed_type, rhs),
5485823f 3451 size_int (lbitsize - 1), 0);
2bc77e10 3452 if (! integer_zerop (tem) && ! integer_all_onesp (tem))
3453 {
c3ceba8e 3454 warning (0, "comparison is always %d due to width of bit-field",
be2828ce 3455 code == NE_EXPR);
20783f07 3456 return constant_boolean_node (code == NE_EXPR, compare_type);
2bc77e10 3457 }
3458 }
3459
3460 /* Single-bit compares should always be against zero. */
3461 if (lbitsize == 1 && ! integer_zerop (rhs))
3462 {
3463 code = code == EQ_EXPR ? NE_EXPR : EQ_EXPR;
3c6185f1 3464 rhs = build_int_cst (type, 0);
2bc77e10 3465 }
3466
3467 /* Make a new bitfield reference, shift the constant over the
3468 appropriate number of bits and mask it with the computed mask
3469 (in case this was a signed field). If we changed it, make a new one. */
4d1060a2 3470 lhs = make_bit_field_ref (linner, unsigned_type, nbitsize, nbitpos, 1);
e03ab35e 3471 if (lvolatilep)
3472 {
3473 TREE_SIDE_EFFECTS (lhs) = 1;
3474 TREE_THIS_VOLATILE (lhs) = 1;
3475 }
2bc77e10 3476
e7be49a3 3477 rhs = const_binop (BIT_AND_EXPR,
3478 const_binop (LSHIFT_EXPR,
3479 fold_convert (unsigned_type, rhs),
3480 size_int (lbitpos), 0),
3481 mask, 0);
2bc77e10 3482
fd96eeef 3483 return build2 (code, compare_type,
3484 build2 (BIT_AND_EXPR, unsigned_type, lhs, mask),
3485 rhs);
2bc77e10 3486}
3487\f
79109eec 3488/* Subroutine for fold_truthop: decode a field reference.
2bc77e10 3489
3490 If EXP is a comparison reference, we return the innermost reference.
3491
3492 *PBITSIZE is set to the number of bits in the reference, *PBITPOS is
3493 set to the starting bit number.
3494
3495 If the innermost field can be completely contained in a mode-sized
3496 unit, *PMODE is set to that mode. Otherwise, it is set to VOIDmode.
3497
3498 *PVOLATILEP is set to 1 if the any expression encountered is volatile;
3499 otherwise it is not changed.
3500
3501 *PUNSIGNEDP is set to the signedness of the field.
3502
3503 *PMASK is set to the mask used. This is either contained in a
3504 BIT_AND_EXPR or derived from the width of the field.
3505
3398e91d 3506 *PAND_MASK is set to the mask found in a BIT_AND_EXPR, if any.
2a6329ae 3507
2bc77e10 3508 Return 0 if this is not a component reference or is one that we can't
3509 do anything with. */
3510
3511static tree
dc81944a 3512decode_field_reference (tree exp, HOST_WIDE_INT *pbitsize,
3513 HOST_WIDE_INT *pbitpos, enum machine_mode *pmode,
3514 int *punsignedp, int *pvolatilep,
de1b648b 3515 tree *pmask, tree *pand_mask)
2bc77e10 3516{
74878f86 3517 tree outer_type = 0;
4843fe7c 3518 tree and_mask = 0;
3519 tree mask, inner, offset;
3520 tree unsigned_type;
02e7a332 3521 unsigned int precision;
2bc77e10 3522
cc049fa3 3523 /* All the optimizations using this function assume integer fields.
e40566fc 3524 There are problems with FP fields since the type_for_size call
3525 below can fail for, e.g., XFmode. */
3526 if (! INTEGRAL_TYPE_P (TREE_TYPE (exp)))
3527 return 0;
3528
74878f86 3529 /* We are interested in the bare arrangement of bits, so strip everything
3530 that doesn't affect the machine mode. However, record the type of the
3531 outermost expression if it may matter below. */
3532 if (TREE_CODE (exp) == NOP_EXPR
3533 || TREE_CODE (exp) == CONVERT_EXPR
3534 || TREE_CODE (exp) == NON_LVALUE_EXPR)
3535 outer_type = TREE_TYPE (exp);
78379bd9 3536 STRIP_NOPS (exp);
2bc77e10 3537
3538 if (TREE_CODE (exp) == BIT_AND_EXPR)
3539 {
4843fe7c 3540 and_mask = TREE_OPERAND (exp, 1);
2bc77e10 3541 exp = TREE_OPERAND (exp, 0);
4843fe7c 3542 STRIP_NOPS (exp); STRIP_NOPS (and_mask);
3543 if (TREE_CODE (and_mask) != INTEGER_CST)
2bc77e10 3544 return 0;
3545 }
3546
bbfbdece 3547 inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
e7e9416e 3548 punsignedp, pvolatilep, false);
94f29e88 3549 if ((inner == exp && and_mask == 0)
155b05dc 3550 || *pbitsize < 0 || offset != 0
3551 || TREE_CODE (inner) == PLACEHOLDER_EXPR)
e233264a 3552 return 0;
cc049fa3 3553
74878f86 3554 /* If the number of bits in the reference is the same as the bitsize of
3555 the outer type, then the outer type gives the signedness. Otherwise
3556 (in case of a small bitfield) the signedness is unchanged. */
18dbec6f 3557 if (outer_type && *pbitsize == TYPE_PRECISION (outer_type))
78a8ed03 3558 *punsignedp = TYPE_UNSIGNED (outer_type);
74878f86 3559
4843fe7c 3560 /* Compute the mask to access the bitfield. */
fa8b888f 3561 unsigned_type = lang_hooks.types.type_for_size (*pbitsize, 1);
4843fe7c 3562 precision = TYPE_PRECISION (unsigned_type);
3563
7016c612 3564 mask = build_int_cst (unsigned_type, -1);
4d28c5d1 3565 mask = force_fit_type (mask, 0, false, false);
0c5713a2 3566
4843fe7c 3567 mask = const_binop (LSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3568 mask = const_binop (RSHIFT_EXPR, mask, size_int (precision - *pbitsize), 0);
3569
3570 /* Merge it with the mask we found in the BIT_AND_EXPR, if any. */
3571 if (and_mask != 0)
7ab7fd4f 3572 mask = fold_build2 (BIT_AND_EXPR, unsigned_type,
3573 fold_convert (unsigned_type, and_mask), mask);
2bc77e10 3574
3575 *pmask = mask;
2a6329ae 3576 *pand_mask = and_mask;
2bc77e10 3577 return inner;
3578}
3579
6ef828f9 3580/* Return nonzero if MASK represents a mask of SIZE ones in the low-order
2bc77e10 3581 bit positions. */
3582
3583static int
de1b648b 3584all_ones_mask_p (tree mask, int size)
2bc77e10 3585{
3586 tree type = TREE_TYPE (mask);
02e7a332 3587 unsigned int precision = TYPE_PRECISION (type);
52a49c7c 3588 tree tmask;
2bc77e10 3589
7016c612 3590 tmask = build_int_cst (lang_hooks.types.signed_type (type), -1);
4d28c5d1 3591 tmask = force_fit_type (tmask, 0, false, false);
0c5713a2 3592
2bc77e10 3593 return
cc049fa3 3594 tree_int_cst_equal (mask,
94f29e88 3595 const_binop (RSHIFT_EXPR,
3596 const_binop (LSHIFT_EXPR, tmask,
3597 size_int (precision - size),
3598 0),
3599 size_int (precision - size), 0));
2bc77e10 3600}
79109eec 3601
203a24c4 3602/* Subroutine for fold: determine if VAL is the INTEGER_CONST that
3603 represents the sign bit of EXP's type. If EXP represents a sign
3604 or zero extension, also test VAL against the unextended type.
3605 The return value is the (sub)expression whose sign bit is VAL,
3606 or NULL_TREE otherwise. */
3607
3608static tree
de1b648b 3609sign_bit_p (tree exp, tree val)
203a24c4 3610{
a4de5624 3611 unsigned HOST_WIDE_INT mask_lo, lo;
3612 HOST_WIDE_INT mask_hi, hi;
203a24c4 3613 int width;
3614 tree t;
3615
95cc2547 3616 /* Tree EXP must have an integral type. */
203a24c4 3617 t = TREE_TYPE (exp);
3618 if (! INTEGRAL_TYPE_P (t))
3619 return NULL_TREE;
3620
3621 /* Tree VAL must be an integer constant. */
3622 if (TREE_CODE (val) != INTEGER_CST
3623 || TREE_CONSTANT_OVERFLOW (val))
3624 return NULL_TREE;
3625
3626 width = TYPE_PRECISION (t);
3627 if (width > HOST_BITS_PER_WIDE_INT)
3628 {
3629 hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
3630 lo = 0;
a4de5624 3631
3632 mask_hi = ((unsigned HOST_WIDE_INT) -1
3633 >> (2 * HOST_BITS_PER_WIDE_INT - width));
3634 mask_lo = -1;
203a24c4 3635 }
3636 else
3637 {
3638 hi = 0;
3639 lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
a4de5624 3640
3641 mask_hi = 0;
3642 mask_lo = ((unsigned HOST_WIDE_INT) -1
3643 >> (HOST_BITS_PER_WIDE_INT - width));
203a24c4 3644 }
3645
a4de5624 3646 /* We mask off those bits beyond TREE_TYPE (exp) so that we can
3647 treat VAL as if it were unsigned. */
3648 if ((TREE_INT_CST_HIGH (val) & mask_hi) == hi
3649 && (TREE_INT_CST_LOW (val) & mask_lo) == lo)
203a24c4 3650 return exp;
3651
3652 /* Handle extension from a narrower type. */
3653 if (TREE_CODE (exp) == NOP_EXPR
3654 && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
3655 return sign_bit_p (TREE_OPERAND (exp, 0), val);
3656
3657 return NULL_TREE;
3658}
3659
79109eec 3660/* Subroutine for fold_truthop: determine if an operand is simple enough
3661 to be evaluated unconditionally. */
3662
cc049fa3 3663static int
de1b648b 3664simple_operand_p (tree exp)
79109eec 3665{
3666 /* Strip any conversions that don't change the machine mode. */
9a73db25 3667 STRIP_NOPS (exp);
79109eec 3668
ce45a448 3669 return (CONSTANT_CLASS_P (exp)
9a73db25 3670 || TREE_CODE (exp) == SSA_NAME
9308e976 3671 || (DECL_P (exp)
79109eec 3672 && ! TREE_ADDRESSABLE (exp)
3673 && ! TREE_THIS_VOLATILE (exp)
7735dddb 3674 && ! DECL_NONLOCAL (exp)
3675 /* Don't regard global variables as simple. They may be
3676 allocated in ways unknown to the compiler (shared memory,
3677 #pragma weak, etc). */
3678 && ! TREE_PUBLIC (exp)
3679 && ! DECL_EXTERNAL (exp)
3680 /* Loading a static variable is unduly expensive, but global
3681 registers aren't expensive. */
3682 && (! TREE_STATIC (exp) || DECL_REGISTER (exp))));
79109eec 3683}
2bc77e10 3684\f
12ec0a8a 3685/* The following functions are subroutines to fold_range_test and allow it to
3686 try to change a logical combination of comparisons into a range test.
3687
3688 For example, both
de1b648b 3689 X == 2 || X == 3 || X == 4 || X == 5
12ec0a8a 3690 and
de1b648b 3691 X >= 2 && X <= 5
12ec0a8a 3692 are converted to
3693 (unsigned) (X - 2) <= 3
3694
ad87de1e 3695 We describe each set of comparisons as being either inside or outside
12ec0a8a 3696 a range, using a variable named like IN_P, and then describe the
3697 range with a lower and upper bound. If one of the bounds is omitted,
3698 it represents either the highest or lowest value of the type.
3699
3700 In the comments below, we represent a range by two numbers in brackets
ad87de1e 3701 preceded by a "+" to designate being inside that range, or a "-" to
12ec0a8a 3702 designate being outside that range, so the condition can be inverted by
3703 flipping the prefix. An omitted bound is represented by a "-". For
3704 example, "- [-, 10]" means being outside the range starting at the lowest
3705 possible value and ending at 10, in other words, being greater than 10.
3706 The range "+ [-, -]" is always true and hence the range "- [-, -]" is
3707 always false.
3708
3709 We set up things so that the missing bounds are handled in a consistent
3710 manner so neither a missing bound nor "true" and "false" need to be
3711 handled using a special case. */
3712
3713/* Return the result of applying CODE to ARG0 and ARG1, but handle the case
3714 of ARG0 and/or ARG1 being omitted, meaning an unlimited range. UPPER0_P
3715 and UPPER1_P are nonzero if the respective argument is an upper bound
3716 and zero for a lower. TYPE, if nonzero, is the type of the result; it
3717 must be specified for a comparison. ARG1 will be converted to ARG0's
3718 type if both are specified. */
6f725368 3719
12ec0a8a 3720static tree
dc81944a 3721range_binop (enum tree_code code, tree type, tree arg0, int upper0_p,
3722 tree arg1, int upper1_p)
12ec0a8a 3723{
7560c8de 3724 tree tem;
12ec0a8a 3725 int result;
3726 int sgn0, sgn1;
6f725368 3727
12ec0a8a 3728 /* If neither arg represents infinity, do the normal operation.
3729 Else, if not a comparison, return infinity. Else handle the special
3730 comparison rules. Note that most of the cases below won't occur, but
3731 are handled for consistency. */
6f725368 3732
12ec0a8a 3733 if (arg0 != 0 && arg1 != 0)
7560c8de 3734 {
7ab7fd4f 3735 tem = fold_build2 (code, type != 0 ? type : TREE_TYPE (arg0),
3736 arg0, fold_convert (TREE_TYPE (arg0), arg1));
7560c8de 3737 STRIP_NOPS (tem);
3738 return TREE_CODE (tem) == INTEGER_CST ? tem : 0;
3739 }
6f725368 3740
ce45a448 3741 if (TREE_CODE_CLASS (code) != tcc_comparison)
12ec0a8a 3742 return 0;
3743
3744 /* Set SGN[01] to -1 if ARG[01] is a lower bound, 1 for upper, and 0
621ba396 3745 for neither. In real maths, we cannot assume open ended ranges are
3746 the same. But, this is computer arithmetic, where numbers are finite.
3747 We can therefore make the transformation of any unbounded range with
3748 the value Z, Z being greater than any representable number. This permits
6312a35e 3749 us to treat unbounded ranges as equal. */
12ec0a8a 3750 sgn0 = arg0 != 0 ? 0 : (upper0_p ? 1 : -1);
263497ab 3751 sgn1 = arg1 != 0 ? 0 : (upper1_p ? 1 : -1);
12ec0a8a 3752 switch (code)
3753 {
621ba396 3754 case EQ_EXPR:
3755 result = sgn0 == sgn1;
3756 break;
3757 case NE_EXPR:
3758 result = sgn0 != sgn1;
12ec0a8a 3759 break;
621ba396 3760 case LT_EXPR:
12ec0a8a 3761 result = sgn0 < sgn1;
3762 break;
621ba396 3763 case LE_EXPR:
3764 result = sgn0 <= sgn1;
3765 break;
3766 case GT_EXPR:
12ec0a8a 3767 result = sgn0 > sgn1;
3768 break;
621ba396 3769 case GE_EXPR:
3770 result = sgn0 >= sgn1;
3771 break;
0dbd1c74 3772 default:
fdada98f 3773 gcc_unreachable ();
12ec0a8a 3774 }
3775
20783f07 3776 return constant_boolean_node (result, type);
12ec0a8a 3777}
cc049fa3 3778\f
12ec0a8a 3779/* Given EXP, a logical expression, set the range it is testing into
3780 variables denoted by PIN_P, PLOW, and PHIGH. Return the expression
62af9abe 3781 actually being tested. *PLOW and *PHIGH will be made of the same type
12ec0a8a 3782 as the returned expression. If EXP is not a comparison, we will most
3783 likely not be returning a useful value and range. */
6f725368 3784
bfd67d2c 3785static tree
de1b648b 3786make_range (tree exp, int *pin_p, tree *plow, tree *phigh)
6f725368 3787{
12ec0a8a 3788 enum tree_code code;
7206da1b 3789 tree arg0 = NULL_TREE, arg1 = NULL_TREE;
3790 tree exp_type = NULL_TREE, arg0_type = NULL_TREE;
12ec0a8a 3791 int in_p, n_in_p;
3792 tree low, high, n_low, n_high;
6f725368 3793
12ec0a8a 3794 /* Start with simply saying "EXP != 0" and then look at the code of EXP
3795 and see if we can refine the range. Some of the cases below may not
3796 happen, but it doesn't seem worth worrying about this. We "continue"
3797 the outer loop when we've changed something; otherwise we "break"
3798 the switch, which will "break" the while. */
6f725368 3799
b30e3dbc 3800 in_p = 0;
3c6185f1 3801 low = high = build_int_cst (TREE_TYPE (exp), 0);
12ec0a8a 3802
3803 while (1)
6f725368 3804 {
12ec0a8a 3805 code = TREE_CODE (exp);
7206da1b 3806 exp_type = TREE_TYPE (exp);
5eb945de 3807
3808 if (IS_EXPR_CODE_CLASS (TREE_CODE_CLASS (code)))
3809 {
651396d6 3810 if (TREE_CODE_LENGTH (code) > 0)
13795292 3811 arg0 = TREE_OPERAND (exp, 0);
ce45a448 3812 if (TREE_CODE_CLASS (code) == tcc_comparison
3813 || TREE_CODE_CLASS (code) == tcc_unary
3814 || TREE_CODE_CLASS (code) == tcc_binary)
7206da1b 3815 arg0_type = TREE_TYPE (arg0);
ce45a448 3816 if (TREE_CODE_CLASS (code) == tcc_binary
3817 || TREE_CODE_CLASS (code) == tcc_comparison
3818 || (TREE_CODE_CLASS (code) == tcc_expression
3f1e707c 3819 && TREE_CODE_LENGTH (code) > 1))
5eb945de 3820 arg1 = TREE_OPERAND (exp, 1);
3821 }
6f725368 3822
12ec0a8a 3823 switch (code)
3824 {
3825 case TRUTH_NOT_EXPR:
3826 in_p = ! in_p, exp = arg0;
3827 continue;
3828
3829 case EQ_EXPR: case NE_EXPR:
3830 case LT_EXPR: case LE_EXPR: case GE_EXPR: case GT_EXPR:
3831 /* We can only do something if the range is testing for zero
3832 and if the second operand is an integer constant. Note that
3833 saying something is "in" the range we make is done by
3834 complementing IN_P since it will set in the initial case of
3835 being not equal to zero; "out" is leaving it alone. */
3836 if (low == 0 || high == 0
3837 || ! integer_zerop (low) || ! integer_zerop (high)
3838 || TREE_CODE (arg1) != INTEGER_CST)
3839 break;
6f725368 3840
12ec0a8a 3841 switch (code)
3842 {
3843 case NE_EXPR: /* - [c, c] */
3844 low = high = arg1;
3845 break;
3846 case EQ_EXPR: /* + [c, c] */
3847 in_p = ! in_p, low = high = arg1;
3848 break;
3849 case GT_EXPR: /* - [-, c] */
3850 low = 0, high = arg1;
3851 break;
3852 case GE_EXPR: /* + [c, -] */
3853 in_p = ! in_p, low = arg1, high = 0;
3854 break;
3855 case LT_EXPR: /* - [c, -] */
3856 low = arg1, high = 0;
3857 break;
3858 case LE_EXPR: /* + [-, c] */
3859 in_p = ! in_p, low = 0, high = arg1;
3860 break;
0dbd1c74 3861 default:
fdada98f 3862 gcc_unreachable ();
12ec0a8a 3863 }
6f725368 3864
c317c285 3865 /* If this is an unsigned comparison, we also know that EXP is
a9e29e86 3866 greater than or equal to zero. We base the range tests we make
3867 on that fact, so we record it here so we can parse existing
7206da1b 3868 range tests. We test arg0_type since often the return type
3869 of, e.g. EQ_EXPR, is boolean. */
3870 if (TYPE_UNSIGNED (arg0_type) && (low == 0 || high == 0))
12ec0a8a 3871 {
5c9198bd 3872 if (! merge_ranges (&n_in_p, &n_low, &n_high,
3873 in_p, low, high, 1,
3c6185f1 3874 build_int_cst (arg0_type, 0),
a9e29e86 3875 NULL_TREE))
12ec0a8a 3876 break;
6f725368 3877
12ec0a8a 3878 in_p = n_in_p, low = n_low, high = n_high;
a9e29e86 3879
751e10d1 3880 /* If the high bound is missing, but we have a nonzero low
e524954a 3881 bound, reverse the range so it goes from zero to the low bound
3882 minus 1. */
3883 if (high == 0 && low && ! integer_zerop (low))
a9e29e86 3884 {
3885 in_p = ! in_p;
3886 high = range_binop (MINUS_EXPR, NULL_TREE, low, 0,
3887 integer_one_node, 0);
3c6185f1 3888 low = build_int_cst (arg0_type, 0);
a9e29e86 3889 }
12ec0a8a 3890 }
7206da1b 3891
3892 exp = arg0;
12ec0a8a 3893 continue;
3894
3895 case NEGATE_EXPR:
3896 /* (-x) IN [a,b] -> x in [-b, -a] */
7206da1b 3897 n_low = range_binop (MINUS_EXPR, exp_type,
3c6185f1 3898 build_int_cst (exp_type, 0),
b30e3dbc 3899 0, high, 1);
7206da1b 3900 n_high = range_binop (MINUS_EXPR, exp_type,
3c6185f1 3901 build_int_cst (exp_type, 0),
b30e3dbc 3902 0, low, 0);
12ec0a8a 3903 low = n_low, high = n_high;
3904 exp = arg0;
3905 continue;
3906
3907 case BIT_NOT_EXPR:
3908 /* ~ X -> -X - 1 */
7206da1b 3909 exp = build2 (MINUS_EXPR, exp_type, negate_expr (arg0),
3c6185f1 3910 build_int_cst (exp_type, 1));
12ec0a8a 3911 continue;
3912
3913 case PLUS_EXPR: case MINUS_EXPR:
3914 if (TREE_CODE (arg1) != INTEGER_CST)
3915 break;
3916
0a8b4135 3917 /* If flag_wrapv and ARG0_TYPE is signed, then we cannot
3918 move a constant to the other side. */
3919 if (flag_wrapv && !TYPE_UNSIGNED (arg0_type))
3920 break;
3921
12ec0a8a 3922 /* If EXP is signed, any overflow in the computation is undefined,
3923 so we don't worry about it so long as our computations on
3924 the bounds don't overflow. For unsigned, overflow is defined
3925 and this is exactly the right thing. */
3926 n_low = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
7206da1b 3927 arg0_type, low, 0, arg1, 0);
12ec0a8a 3928 n_high = range_binop (code == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR,
7206da1b 3929 arg0_type, high, 1, arg1, 0);
12ec0a8a 3930 if ((n_low != 0 && TREE_OVERFLOW (n_low))
3931 || (n_high != 0 && TREE_OVERFLOW (n_high)))
3932 break;
3933
6b457c77 3934 /* Check for an unsigned range which has wrapped around the maximum
3935 value thus making n_high < n_low, and normalize it. */
98db800f 3936 if (n_low && n_high && tree_int_cst_lt (n_high, n_low))
6b457c77 3937 {
7206da1b 3938 low = range_binop (PLUS_EXPR, arg0_type, n_high, 0,
a9e29e86 3939 integer_one_node, 0);
7206da1b 3940 high = range_binop (MINUS_EXPR, arg0_type, n_low, 0,
a80d786b 3941 integer_one_node, 0);
3942
3943 /* If the range is of the form +/- [ x+1, x ], we won't
3944 be able to normalize it. But then, it represents the
3945 whole range or the empty set, so make it
3946 +/- [ -, - ]. */
3947 if (tree_int_cst_equal (n_low, low)
3948 && tree_int_cst_equal (n_high, high))
3949 low = high = 0;
3950 else
3951 in_p = ! in_p;
6b457c77 3952 }
98db800f 3953 else
3954 low = n_low, high = n_high;
7560c8de 3955
12ec0a8a 3956 exp = arg0;
3957 continue;
3958
3959 case NOP_EXPR: case NON_LVALUE_EXPR: case CONVERT_EXPR:
7206da1b 3960 if (TYPE_PRECISION (arg0_type) > TYPE_PRECISION (exp_type))
d6d65bd2 3961 break;
3962
7206da1b 3963 if (! INTEGRAL_TYPE_P (arg0_type)
3964 || (low != 0 && ! int_fits_type_p (low, arg0_type))
3965 || (high != 0 && ! int_fits_type_p (high, arg0_type)))
12ec0a8a 3966 break;
3967
4cd44a59 3968 n_low = low, n_high = high;
12ec0a8a 3969
4cd44a59 3970 if (n_low != 0)
7206da1b 3971 n_low = fold_convert (arg0_type, n_low);
4cd44a59 3972
3973 if (n_high != 0)
7206da1b 3974 n_high = fold_convert (arg0_type, n_high);
4cd44a59 3975
4cd44a59 3976
7206da1b 3977 /* If we're converting arg0 from an unsigned type, to exp,
2c763ed4 3978 a signed type, we will be doing the comparison as unsigned.
7206da1b 3979 The tests above have already verified that LOW and HIGH
3980 are both positive.
3981
3982 So we have to ensure that we will handle large unsigned
3983 values the same way that the current signed bounds treat
3984 negative values. */
3985
3986 if (!TYPE_UNSIGNED (exp_type) && TYPE_UNSIGNED (arg0_type))
4cd44a59 3987 {
f52483b5 3988 tree high_positive;
7206da1b 3989 tree equiv_type = lang_hooks.types.type_for_mode
3990 (TYPE_MODE (arg0_type), 1);
f52483b5 3991
3992 /* A range without an upper bound is, naturally, unbounded.
3993 Since convert would have cropped a very large value, use
155b05dc 3994 the max value for the destination type. */
3995 high_positive
3996 = TYPE_MAX_VALUE (equiv_type) ? TYPE_MAX_VALUE (equiv_type)
7206da1b 3997 : TYPE_MAX_VALUE (arg0_type);
f52483b5 3998
7206da1b 3999 if (TYPE_PRECISION (exp_type) == TYPE_PRECISION (arg0_type))
7ab7fd4f 4000 high_positive = fold_build2 (RSHIFT_EXPR, arg0_type,
4001 fold_convert (arg0_type,
4002 high_positive),
4003 fold_convert (arg0_type,
4004 integer_one_node));
cc049fa3 4005
4cd44a59 4006 /* If the low bound is specified, "and" the range with the
4007 range for which the original unsigned value will be
4008 positive. */
4009 if (low != 0)
4010 {
4011 if (! merge_ranges (&n_in_p, &n_low, &n_high,
b30e3dbc 4012 1, n_low, n_high, 1,
5c9198bd 4013 fold_convert (arg0_type,
4014 integer_zero_node),
4cd44a59 4015 high_positive))
4016 break;
4017
4018 in_p = (n_in_p == in_p);
4019 }
4020 else
4021 {
4022 /* Otherwise, "or" the range with the range of the input
4023 that will be interpreted as negative. */
4024 if (! merge_ranges (&n_in_p, &n_low, &n_high,
b30e3dbc 4025 0, n_low, n_high, 1,
5c9198bd 4026 fold_convert (arg0_type,
4027 integer_zero_node),
4cd44a59 4028 high_positive))
4029 break;
4030
4031 in_p = (in_p != n_in_p);
4032 }
4033 }
12ec0a8a 4034
4035 exp = arg0;
4cd44a59 4036 low = n_low, high = n_high;
12ec0a8a 4037 continue;
4cd44a59 4038
4039 default:
4040 break;
6f725368 4041 }
12ec0a8a 4042
4043 break;
6f725368 4044 }
12ec0a8a 4045
f83854c8 4046 /* If EXP is a constant, we can evaluate whether this is true or false. */
4047 if (TREE_CODE (exp) == INTEGER_CST)
4048 {
4049 in_p = in_p == (integer_onep (range_binop (GE_EXPR, integer_type_node,
4050 exp, 0, low, 0))
4051 && integer_onep (range_binop (LE_EXPR, integer_type_node,
4052 exp, 1, high, 1)));
4053 low = high = 0;
4054 exp = 0;
4055 }
4056
12ec0a8a 4057 *pin_p = in_p, *plow = low, *phigh = high;
4058 return exp;
4059}
4060\f
4061/* Given a range, LOW, HIGH, and IN_P, an expression, EXP, and a result
4062 type, TYPE, return an expression to test if EXP is in (or out of, depending
3b3a787a 4063 on IN_P) the range. Return 0 if the test couldn't be created. */
12ec0a8a 4064
4065static tree
de1b648b 4066build_range_check (tree type, tree exp, int in_p, tree low, tree high)
12ec0a8a 4067{
4068 tree etype = TREE_TYPE (exp);
843dd7a3 4069 tree value;
12ec0a8a 4070
d067185e 4071#ifdef HAVE_canonicalize_funcptr_for_compare
4072 /* Disable this optimization for function pointer expressions
4073 on targets that require function pointer canonicalization. */
4074 if (HAVE_canonicalize_funcptr_for_compare
4075 && TREE_CODE (etype) == POINTER_TYPE
4076 && TREE_CODE (TREE_TYPE (etype)) == FUNCTION_TYPE)
4077 return NULL_TREE;
4078#endif
4079
3b3a787a 4080 if (! in_p)
4081 {
4082 value = build_range_check (type, exp, 1, low, high);
4083 if (value != 0)
4084 return invert_truthvalue (value);
4085
4086 return 0;
4087 }
12ec0a8a 4088
843dd7a3 4089 if (low == 0 && high == 0)
3c6185f1 4090 return build_int_cst (type, 1);
12ec0a8a 4091
843dd7a3 4092 if (low == 0)
2fdd1d9f 4093 return fold_build2 (LE_EXPR, type, exp,
4094 fold_convert (etype, high));
12ec0a8a 4095
843dd7a3 4096 if (high == 0)
2fdd1d9f 4097 return fold_build2 (GE_EXPR, type, exp,
4098 fold_convert (etype, low));
12ec0a8a 4099
843dd7a3 4100 if (operand_equal_p (low, high, 0))
2fdd1d9f 4101 return fold_build2 (EQ_EXPR, type, exp,
4102 fold_convert (etype, low));
12ec0a8a 4103
843dd7a3 4104 if (integer_zerop (low))
6f725368 4105 {
78a8ed03 4106 if (! TYPE_UNSIGNED (etype))
d3371fcd 4107 {
fa8b888f 4108 etype = lang_hooks.types.unsigned_type (etype);
b30e3dbc 4109 high = fold_convert (etype, high);
4110 exp = fold_convert (etype, exp);
d3371fcd 4111 }
843dd7a3 4112 return build_range_check (type, exp, 1, 0, high);
12ec0a8a 4113 }
6f725368 4114
843dd7a3 4115 /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
4116 if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
4117 {
4118 unsigned HOST_WIDE_INT lo;
4119 HOST_WIDE_INT hi;
4120 int prec;
4121
4122 prec = TYPE_PRECISION (etype);
4123 if (prec <= HOST_BITS_PER_WIDE_INT)
d3371fcd 4124 {
4125 hi = 0;
4126 lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
4127 }
843dd7a3 4128 else
d3371fcd 4129 {
4130 hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
4131 lo = (unsigned HOST_WIDE_INT) -1;
4132 }
843dd7a3 4133
4134 if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
d3371fcd 4135 {
78a8ed03 4136 if (TYPE_UNSIGNED (etype))
d3371fcd 4137 {
fa8b888f 4138 etype = lang_hooks.types.signed_type (etype);
b30e3dbc 4139 exp = fold_convert (etype, exp);
d3371fcd 4140 }
7ab7fd4f 4141 return fold_build2 (GT_EXPR, type, exp,
3c6185f1 4142 build_int_cst (etype, 0));
d3371fcd 4143 }
843dd7a3 4144 }
4145
66108e20 4146 /* Optimize (c>=low) && (c<=high) into (c-low>=0) && (c-low<=high-low).
4147 This requires wrap-around arithmetics for the type of the expression. */
4148 switch (TREE_CODE (etype))
4149 {
4150 case INTEGER_TYPE:
4151 /* There is no requirement that LOW be within the range of ETYPE
4152 if the latter is a subtype. It must, however, be within the base
4153 type of ETYPE. So be sure we do the subtraction in that type. */
4154 if (TREE_TYPE (etype))
4155 etype = TREE_TYPE (etype);
4156 break;
4157
4158 case ENUMERAL_TYPE:
4159 case BOOLEAN_TYPE:
4160 etype = lang_hooks.types.type_for_size (TYPE_PRECISION (etype),
4161 TYPE_UNSIGNED (etype));
4162 break;
4163
4164 default:
4165 break;
4166 }
4167
4168 /* If we don't have wrap-around arithmetics upfront, try to force it. */
4169 if (TREE_CODE (etype) == INTEGER_TYPE
4170 && !TYPE_UNSIGNED (etype) && !flag_wrapv)
3b3a787a 4171 {
4172 tree utype, minv, maxv;
4173
4174 /* Check if (unsigned) INT_MAX + 1 == (unsigned) INT_MIN
4175 for the type in question, as we rely on this here. */
66108e20 4176 utype = lang_hooks.types.unsigned_type (etype);
4177 maxv = fold_convert (utype, TYPE_MAX_VALUE (etype));
4178 maxv = range_binop (PLUS_EXPR, NULL_TREE, maxv, 1,
4179 integer_one_node, 1);
4180 minv = fold_convert (utype, TYPE_MIN_VALUE (etype));
4181
4182 if (integer_zerop (range_binop (NE_EXPR, integer_type_node,
4183 minv, 1, maxv, 1)))
4184 etype = utype;
4185 else
4186 return 0;
3b3a787a 4187 }
4188
66108e20 4189 high = fold_convert (etype, high);
4190 low = fold_convert (etype, low);
4191 exp = fold_convert (etype, exp);
3f7c18bc 4192
66108e20 4193 value = const_binop (MINUS_EXPR, high, low, 0);
4194
4195 if (value != 0 && !TREE_OVERFLOW (value))
4196 return build_range_check (type,
4197 fold_build2 (MINUS_EXPR, etype, exp, low),
4198 1, build_int_cst (etype, 0), value);
843dd7a3 4199
4200 return 0;
12ec0a8a 4201}
4202\f
1557b0a0 4203/* Return the predecessor of VAL in its type, handling the infinite case. */
4204
4205static tree
4206range_predecessor (tree val)
4207{
4208 tree type = TREE_TYPE (val);
4209
20efd591 4210 if (INTEGRAL_TYPE_P (type)
4211 && operand_equal_p (val, TYPE_MIN_VALUE (type), 0))
1557b0a0 4212 return 0;
4213 else
4214 return range_binop (MINUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4215}
4216
4217/* Return the successor of VAL in its type, handling the infinite case. */
4218
4219static tree
4220range_successor (tree val)
4221{
4222 tree type = TREE_TYPE (val);
4223
20efd591 4224 if (INTEGRAL_TYPE_P (type)
4225 && operand_equal_p (val, TYPE_MAX_VALUE (type), 0))
1557b0a0 4226 return 0;
4227 else
4228 return range_binop (PLUS_EXPR, NULL_TREE, val, 0, integer_one_node, 0);
4229}
4230
cc049fa3 4231/* Given two ranges, see if we can merge them into one. Return 1 if we
12ec0a8a 4232 can, 0 if we can't. Set the output range into the specified parameters. */
6f725368 4233
12ec0a8a 4234static int
dc81944a 4235merge_ranges (int *pin_p, tree *plow, tree *phigh, int in0_p, tree low0,
4236 tree high0, int in1_p, tree low1, tree high1)
12ec0a8a 4237{
4238 int no_overlap;
4239 int subset;
4240 int temp;
4241 tree tem;
4242 int in_p;
4243 tree low, high;
4cd44a59 4244 int lowequal = ((low0 == 0 && low1 == 0)
4245 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4246 low0, 0, low1, 0)));
4247 int highequal = ((high0 == 0 && high1 == 0)
4248 || integer_onep (range_binop (EQ_EXPR, integer_type_node,
4249 high0, 1, high1, 1)));
4250
4251 /* Make range 0 be the range that starts first, or ends last if they
4252 start at the same value. Swap them if it isn't. */
cc049fa3 4253 if (integer_onep (range_binop (GT_EXPR, integer_type_node,
12ec0a8a 4254 low0, 0, low1, 0))
4cd44a59 4255 || (lowequal
12ec0a8a 4256 && integer_onep (range_binop (GT_EXPR, integer_type_node,
4cd44a59 4257 high1, 1, high0, 1))))
12ec0a8a 4258 {
4259 temp = in0_p, in0_p = in1_p, in1_p = temp;
4260 tem = low0, low0 = low1, low1 = tem;
4261 tem = high0, high0 = high1, high1 = tem;
4262 }
6f725368 4263
12ec0a8a 4264 /* Now flag two cases, whether the ranges are disjoint or whether the
4265 second range is totally subsumed in the first. Note that the tests
4266 below are simplified by the ones above. */
4267 no_overlap = integer_onep (range_binop (LT_EXPR, integer_type_node,
4268 high0, 1, low1, 0));
718acf6d 4269 subset = integer_onep (range_binop (LE_EXPR, integer_type_node,
12ec0a8a 4270 high1, 1, high0, 1));
4271
4272 /* We now have four cases, depending on whether we are including or
4273 excluding the two ranges. */
4274 if (in0_p && in1_p)
4275 {
4276 /* If they don't overlap, the result is false. If the second range
4277 is a subset it is the result. Otherwise, the range is from the start
4278 of the second to the end of the first. */
4279 if (no_overlap)
4280 in_p = 0, low = high = 0;
4281 else if (subset)
4282 in_p = 1, low = low1, high = high1;
4283 else
4284 in_p = 1, low = low1, high = high0;
4285 }
6f725368 4286
12ec0a8a 4287 else if (in0_p && ! in1_p)
4288 {
4cd44a59 4289 /* If they don't overlap, the result is the first range. If they are
4290 equal, the result is false. If the second range is a subset of the
4291 first, and the ranges begin at the same place, we go from just after
66108e20 4292 the end of the second range to the end of the first. If the second
4cd44a59 4293 range is not a subset of the first, or if it is a subset and both
4294 ranges end at the same place, the range starts at the start of the
4295 first range and ends just before the second range.
4296 Otherwise, we can't describe this as a single range. */
12ec0a8a 4297 if (no_overlap)
4298 in_p = 1, low = low0, high = high0;
4cd44a59 4299 else if (lowequal && highequal)
08986c47 4300 in_p = 0, low = high = 0;
4cd44a59 4301 else if (subset && lowequal)
4302 {
66108e20 4303 low = range_successor (high1);
4304 high = high0;
4305 in_p = (low != 0);
4cd44a59 4306 }
4307 else if (! subset || highequal)
12ec0a8a 4308 {
66108e20 4309 low = low0;
4310 high = range_predecessor (low1);
4311 in_p = (high != 0);
12ec0a8a 4312 }
4cd44a59 4313 else
4314 return 0;
12ec0a8a 4315 }
6f725368 4316
12ec0a8a 4317 else if (! in0_p && in1_p)
4318 {
4319 /* If they don't overlap, the result is the second range. If the second
4320 is a subset of the first, the result is false. Otherwise,
4321 the range starts just after the first range and ends at the
4322 end of the second. */
4323 if (no_overlap)
4324 in_p = 1, low = low1, high = high1;
155b05dc 4325 else if (subset || highequal)
12ec0a8a 4326 in_p = 0, low = high = 0;
4327 else
4328 {
66108e20 4329 low = range_successor (high0);
4330 high = high1;
4331 in_p = (low != 0);
6f725368 4332 }
4333 }
4334
12ec0a8a 4335 else
4336 {
4337 /* The case where we are excluding both ranges. Here the complex case
4338 is if they don't overlap. In that case, the only time we have a
4339 range is if they are adjacent. If the second is a subset of the
4340 first, the result is the first. Otherwise, the range to exclude
4341 starts at the beginning of the first range and ends at the end of the
4342 second. */
4343 if (no_overlap)
4344 {
4345 if (integer_onep (range_binop (EQ_EXPR, integer_type_node,
66108e20 4346 range_successor (high0),
12ec0a8a 4347 1, low1, 0)))
4348 in_p = 0, low = low0, high = high1;
4349 else
3b3a787a 4350 {
4351 /* Canonicalize - [min, x] into - [-, x]. */
4352 if (low0 && TREE_CODE (low0) == INTEGER_CST)
4353 switch (TREE_CODE (TREE_TYPE (low0)))
4354 {
4355 case ENUMERAL_TYPE:
4356 if (TYPE_PRECISION (TREE_TYPE (low0))
4357 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (low0))))
4358 break;
4359 /* FALLTHROUGH */
4360 case INTEGER_TYPE:
3b3a787a 4361 if (tree_int_cst_equal (low0,
4362 TYPE_MIN_VALUE (TREE_TYPE (low0))))
4363 low0 = 0;
4364 break;
4365 case POINTER_TYPE:
4366 if (TYPE_UNSIGNED (TREE_TYPE (low0))
4367 && integer_zerop (low0))
4368 low0 = 0;
4369 break;
4370 default:
4371 break;
4372 }
4373
4374 /* Canonicalize - [x, max] into - [x, -]. */
4375 if (high1 && TREE_CODE (high1) == INTEGER_CST)
4376 switch (TREE_CODE (TREE_TYPE (high1)))
4377 {
4378 case ENUMERAL_TYPE:
4379 if (TYPE_PRECISION (TREE_TYPE (high1))
4380 != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (high1))))
4381 break;
4382 /* FALLTHROUGH */
4383 case INTEGER_TYPE:
3b3a787a 4384 if (tree_int_cst_equal (high1,
4385 TYPE_MAX_VALUE (TREE_TYPE (high1))))
4386 high1 = 0;
4387 break;
4388 case POINTER_TYPE:
4389 if (TYPE_UNSIGNED (TREE_TYPE (high1))
4390 && integer_zerop (range_binop (PLUS_EXPR, NULL_TREE,
4391 high1, 1,
4392 integer_one_node, 1)))
4393 high1 = 0;
4394 break;
4395 default:
4396 break;
4397 }
4398
4399 /* The ranges might be also adjacent between the maximum and
4400 minimum values of the given type. For
4401 - [{min,-}, x] and - [y, {max,-}] ranges where x + 1 < y
4402 return + [x + 1, y - 1]. */
4403 if (low0 == 0 && high1 == 0)
4404 {
1557b0a0 4405 low = range_successor (high0);
4406 high = range_predecessor (low1);
3b3a787a 4407 if (low == 0 || high == 0)
4408 return 0;
4409
4410 in_p = 1;
4411 }
4412 else
4413 return 0;
4414 }
12ec0a8a 4415 }
4416 else if (subset)
4417 in_p = 0, low = low0, high = high0;
4418 else
4419 in_p = 0, low = low0, high = high1;
4420 }
b29eae68 4421
12ec0a8a 4422 *pin_p = in_p, *plow = low, *phigh = high;
4423 return 1;
4424}
0023616d 4425\f
4426
4427/* Subroutine of fold, looking inside expressions of the form
9b1fa4a0 4428 A op B ? A : C, where ARG0, ARG1 and ARG2 are the three operands
4429 of the COND_EXPR. This function is being used also to optimize
4430 A op B ? C : A, by reversing the comparison first.
0023616d 4431
4432 Return a folded expression whose code is not a COND_EXPR
4433 anymore, or NULL_TREE if no folding opportunity is found. */
4434
4435static tree
9b1fa4a0 4436fold_cond_expr_with_comparison (tree type, tree arg0, tree arg1, tree arg2)
0023616d 4437{
4438 enum tree_code comp_code = TREE_CODE (arg0);
4439 tree arg00 = TREE_OPERAND (arg0, 0);
4440 tree arg01 = TREE_OPERAND (arg0, 1);
9b1fa4a0 4441 tree arg1_type = TREE_TYPE (arg1);
0023616d 4442 tree tem;
9b1fa4a0 4443
4444 STRIP_NOPS (arg1);
0023616d 4445 STRIP_NOPS (arg2);
4446
4447 /* If we have A op 0 ? A : -A, consider applying the following
4448 transformations:
4449
4450 A == 0? A : -A same as -A
4451 A != 0? A : -A same as A
4452 A >= 0? A : -A same as abs (A)
4453 A > 0? A : -A same as abs (A)
4454 A <= 0? A : -A same as -abs (A)
4455 A < 0? A : -A same as -abs (A)
4456
4457 None of these transformations work for modes with signed
4458 zeros. If A is +/-0, the first two transformations will
4459 change the sign of the result (from +0 to -0, or vice
4460 versa). The last four will fix the sign of the result,
4461 even though the original expressions could be positive or
4462 negative, depending on the sign of A.
4463
4464 Note that all these transformations are correct if A is
4465 NaN, since the two alternatives (A and -A) are also NaNs. */
4466 if ((FLOAT_TYPE_P (TREE_TYPE (arg01))
4467 ? real_zerop (arg01)
4468 : integer_zerop (arg01))
38f916c2 4469 && ((TREE_CODE (arg2) == NEGATE_EXPR
4470 && operand_equal_p (TREE_OPERAND (arg2, 0), arg1, 0))
4471 /* In the case that A is of the form X-Y, '-A' (arg2) may
4472 have already been folded to Y-X, check for that. */
4473 || (TREE_CODE (arg1) == MINUS_EXPR
4474 && TREE_CODE (arg2) == MINUS_EXPR
4475 && operand_equal_p (TREE_OPERAND (arg1, 0),
4476 TREE_OPERAND (arg2, 1), 0)
4477 && operand_equal_p (TREE_OPERAND (arg1, 1),
4478 TREE_OPERAND (arg2, 0), 0))))
0023616d 4479 switch (comp_code)
4480 {
4481 case EQ_EXPR:
fe9b47eb 4482 case UNEQ_EXPR:
9b1fa4a0 4483 tem = fold_convert (arg1_type, arg1);
4484 return pedantic_non_lvalue (fold_convert (type, negate_expr (tem)));
0023616d 4485 case NE_EXPR:
fe9b47eb 4486 case LTGT_EXPR:
9b1fa4a0 4487 return pedantic_non_lvalue (fold_convert (type, arg1));
fe9b47eb 4488 case UNGE_EXPR:
4489 case UNGT_EXPR:
4490 if (flag_trapping_math)
4491 break;
4492 /* Fall through. */
0023616d 4493 case GE_EXPR:
4494 case GT_EXPR:
9b1fa4a0 4495 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4496 arg1 = fold_convert (lang_hooks.types.signed_type
4497 (TREE_TYPE (arg1)), arg1);
7ab7fd4f 4498 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
0023616d 4499 return pedantic_non_lvalue (fold_convert (type, tem));
fe9b47eb 4500 case UNLE_EXPR:
4501 case UNLT_EXPR:
4502 if (flag_trapping_math)
4503 break;
0023616d 4504 case LE_EXPR:
4505 case LT_EXPR:
9b1fa4a0 4506 if (TYPE_UNSIGNED (TREE_TYPE (arg1)))
4507 arg1 = fold_convert (lang_hooks.types.signed_type
4508 (TREE_TYPE (arg1)), arg1);
7ab7fd4f 4509 tem = fold_build1 (ABS_EXPR, TREE_TYPE (arg1), arg1);
0023616d 4510 return negate_expr (fold_convert (type, tem));
4511 default:
ce45a448 4512 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
fe9b47eb 4513 break;
0023616d 4514 }
4515
4516 /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
4517 A == 0 ? A : 0 is always 0 unless A is -0. Note that
4518 both transformations are correct when A is NaN: A != 0
4519 is then true, and A == 0 is false. */
4520
4521 if (integer_zerop (arg01) && integer_zerop (arg2))
4522 {
4523 if (comp_code == NE_EXPR)
9b1fa4a0 4524 return pedantic_non_lvalue (fold_convert (type, arg1));
0023616d 4525 else if (comp_code == EQ_EXPR)
3c6185f1 4526 return build_int_cst (type, 0);
0023616d 4527 }
4528
4529 /* Try some transformations of A op B ? A : B.
4530
4531 A == B? A : B same as B
4532 A != B? A : B same as A
4533 A >= B? A : B same as max (A, B)
4534 A > B? A : B same as max (B, A)
4535 A <= B? A : B same as min (A, B)
4536 A < B? A : B same as min (B, A)
4537
4538 As above, these transformations don't work in the presence
4539 of signed zeros. For example, if A and B are zeros of
4540 opposite sign, the first two transformations will change
4541 the sign of the result. In the last four, the original
4542 expressions give different results for (A=+0, B=-0) and
4543 (A=-0, B=+0), but the transformed expressions do not.
4544
4545 The first two transformations are correct if either A or B
4546 is a NaN. In the first transformation, the condition will
4547 be false, and B will indeed be chosen. In the case of the
4548 second transformation, the condition A != B will be true,
4549 and A will be chosen.
4550
4551 The conversions to max() and min() are not correct if B is
4552 a number and A is not. The conditions in the original
4553 expressions will be false, so all four give B. The min()
4554 and max() versions would give a NaN instead. */
98fc7ffa 4555 if (operand_equal_for_comparison_p (arg01, arg2, arg00)
4556 /* Avoid these transformations if the COND_EXPR may be used
4557 as an lvalue in the C++ front-end. PR c++/19199. */
4558 && (in_gimple_form
d0911b8e 4559 || (strcmp (lang_hooks.name, "GNU C++") != 0
4560 && strcmp (lang_hooks.name, "GNU Objective-C++") != 0)
98fc7ffa 4561 || ! maybe_lvalue_p (arg1)
4562 || ! maybe_lvalue_p (arg2)))
0023616d 4563 {
4564 tree comp_op0 = arg00;
4565 tree comp_op1 = arg01;
4566 tree comp_type = TREE_TYPE (comp_op0);
4567
4568 /* Avoid adding NOP_EXPRs in case this is an lvalue. */
4569 if (TYPE_MAIN_VARIANT (comp_type) == TYPE_MAIN_VARIANT (type))
4570 {
4571 comp_type = type;
9b1fa4a0 4572 comp_op0 = arg1;
0023616d 4573 comp_op1 = arg2;
4574 }
4575
4576 switch (comp_code)
4577 {
4578 case EQ_EXPR:
4579 return pedantic_non_lvalue (fold_convert (type, arg2));
4580 case NE_EXPR:
9b1fa4a0 4581 return pedantic_non_lvalue (fold_convert (type, arg1));
0023616d 4582 case LE_EXPR:
4583 case LT_EXPR:
fe9b47eb 4584 case UNLE_EXPR:
4585 case UNLT_EXPR:
0023616d 4586 /* In C++ a ?: expression can be an lvalue, so put the
4587 operand which will be used if they are equal first
4588 so that we can convert this back to the
4589 corresponding COND_EXPR. */
9b1fa4a0 4590 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5c9198bd 4591 {
4592 comp_op0 = fold_convert (comp_type, comp_op0);
4593 comp_op1 = fold_convert (comp_type, comp_op1);
fe9b47eb 4594 tem = (comp_code == LE_EXPR || comp_code == UNLE_EXPR)
7ab7fd4f 4595 ? fold_build2 (MIN_EXPR, comp_type, comp_op0, comp_op1)
4596 : fold_build2 (MIN_EXPR, comp_type, comp_op1, comp_op0);
5c9198bd 4597 return pedantic_non_lvalue (fold_convert (type, tem));
4598 }
0023616d 4599 break;
4600 case GE_EXPR:
4601 case GT_EXPR:
fe9b47eb 4602 case UNGE_EXPR:
4603 case UNGT_EXPR:
9b1fa4a0 4604 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
5c9198bd 4605 {
4606 comp_op0 = fold_convert (comp_type, comp_op0);
4607 comp_op1 = fold_convert (comp_type, comp_op1);
fe9b47eb 4608 tem = (comp_code == GE_EXPR || comp_code == UNGE_EXPR)
7ab7fd4f 4609 ? fold_build2 (MAX_EXPR, comp_type, comp_op0, comp_op1)
4610 : fold_build2 (MAX_EXPR, comp_type, comp_op1, comp_op0);
5c9198bd 4611 return pedantic_non_lvalue (fold_convert (type, tem));
4612 }
0023616d 4613 break;
fe9b47eb 4614 case UNEQ_EXPR:
4615 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4616 return pedantic_non_lvalue (fold_convert (type, arg2));
4617 break;
4618 case LTGT_EXPR:
4619 if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
4620 return pedantic_non_lvalue (fold_convert (type, arg1));
4621 break;
0023616d 4622 default:
ce45a448 4623 gcc_assert (TREE_CODE_CLASS (comp_code) == tcc_comparison);
fe9b47eb 4624 break;
0023616d 4625 }
4626 }
4627
4628 /* If this is A op C1 ? A : C2 with C1 and C2 constant integers,
4629 we might still be able to simplify this. For example,
4630 if C1 is one less or one more than C2, this might have started
4631 out as a MIN or MAX and been transformed by this function.
4632 Only good for INTEGER_TYPEs, because we need TYPE_MAX_VALUE. */
4633
4634 if (INTEGRAL_TYPE_P (type)
4635 && TREE_CODE (arg01) == INTEGER_CST
4636 && TREE_CODE (arg2) == INTEGER_CST)
4637 switch (comp_code)
4638 {
4639 case EQ_EXPR:
4640 /* We can replace A with C1 in this case. */
9b1fa4a0 4641 arg1 = fold_convert (type, arg01);
7ab7fd4f 4642 return fold_build3 (COND_EXPR, type, arg0, arg1, arg2);
0023616d 4643
4644 case LT_EXPR:
4645 /* If C1 is C2 + 1, this is min(A, C2). */
4646 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4647 OEP_ONLY_CONST)
4648 && operand_equal_p (arg01,
4649 const_binop (PLUS_EXPR, arg2,
4650 integer_one_node, 0),
4651 OEP_ONLY_CONST))
7ab7fd4f 4652 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4653 type, arg1, arg2));
0023616d 4654 break;
4655
4656 case LE_EXPR:
4657 /* If C1 is C2 - 1, this is min(A, C2). */
4658 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4659 OEP_ONLY_CONST)
4660 && operand_equal_p (arg01,
4661 const_binop (MINUS_EXPR, arg2,
4662 integer_one_node, 0),
4663 OEP_ONLY_CONST))
7ab7fd4f 4664 return pedantic_non_lvalue (fold_build2 (MIN_EXPR,
4665 type, arg1, arg2));
0023616d 4666 break;
4667
4668 case GT_EXPR:
4669 /* If C1 is C2 - 1, this is max(A, C2). */
4670 if (! operand_equal_p (arg2, TYPE_MIN_VALUE (type),
4671 OEP_ONLY_CONST)
4672 && operand_equal_p (arg01,
4673 const_binop (MINUS_EXPR, arg2,
4674 integer_one_node, 0),
4675 OEP_ONLY_CONST))
7ab7fd4f 4676 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4677 type, arg1, arg2));
0023616d 4678 break;
4679
4680 case GE_EXPR:
4681 /* If C1 is C2 + 1, this is max(A, C2). */
4682 if (! operand_equal_p (arg2, TYPE_MAX_VALUE (type),
4683 OEP_ONLY_CONST)
4684 && operand_equal_p (arg01,
4685 const_binop (PLUS_EXPR, arg2,
4686 integer_one_node, 0),
4687 OEP_ONLY_CONST))
7ab7fd4f 4688 return pedantic_non_lvalue (fold_build2 (MAX_EXPR,
4689 type, arg1, arg2));
0023616d 4690 break;
4691 case NE_EXPR:
4692 break;
4693 default:
fdada98f 4694 gcc_unreachable ();
0023616d 4695 }
4696
4697 return NULL_TREE;
4698}
4699
4700
12ec0a8a 4701\f
17529f98 4702#ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
4703#define LOGICAL_OP_NON_SHORT_CIRCUIT (BRANCH_COST >= 2)
cf451ad8 4704#endif
4705
12ec0a8a 4706/* EXP is some logical combination of boolean tests. See if we can
4707 merge it into some range test. Return the new tree if so. */
6f725368 4708
12ec0a8a 4709static tree
2c17ebb2 4710fold_range_test (enum tree_code code, tree type, tree op0, tree op1)
12ec0a8a 4711{
2c17ebb2 4712 int or_op = (code == TRUTH_ORIF_EXPR
4713 || code == TRUTH_OR_EXPR);
12ec0a8a 4714 int in0_p, in1_p, in_p;
4715 tree low0, low1, low, high0, high1, high;
2c17ebb2 4716 tree lhs = make_range (op0, &in0_p, &low0, &high0);
4717 tree rhs = make_range (op1, &in1_p, &low1, &high1);
12ec0a8a 4718 tree tem;
6f725368 4719
12ec0a8a 4720 /* If this is an OR operation, invert both sides; we will invert
4721 again at the end. */
4722 if (or_op)
4723 in0_p = ! in0_p, in1_p = ! in1_p;
4724
4725 /* If both expressions are the same, if we can merge the ranges, and we
f83854c8 4726 can build the range test, return it or it inverted. If one of the
4727 ranges is always true or always false, consider it to be the same
4728 expression as the other. */
4729 if ((lhs == 0 || rhs == 0 || operand_equal_p (lhs, rhs, 0))
12ec0a8a 4730 && merge_ranges (&in_p, &low, &high, in0_p, low0, high0,
4731 in1_p, low1, high1)
2c17ebb2 4732 && 0 != (tem = (build_range_check (type,
f83854c8 4733 lhs != 0 ? lhs
4734 : rhs != 0 ? rhs : integer_zero_node,
12ec0a8a 4735 in_p, low, high))))
4736 return or_op ? invert_truthvalue (tem) : tem;
4737
4738 /* On machines where the branch cost is expensive, if this is a
4739 short-circuited branch and the underlying object on both sides
4740 is the same, make a non-short-circuit operation. */
17529f98 4741 else if (LOGICAL_OP_NON_SHORT_CIRCUIT
1fdbc76b 4742 && lhs != 0 && rhs != 0
2c17ebb2 4743 && (code == TRUTH_ANDIF_EXPR
4744 || code == TRUTH_ORIF_EXPR)
12ec0a8a 4745 && operand_equal_p (lhs, rhs, 0))
6f725368 4746 {
90a73592 4747 /* If simple enough, just rewrite. Otherwise, make a SAVE_EXPR
9e042f31 4748 unless we are at top level or LHS contains a PLACEHOLDER_EXPR, in
4749 which cases we can't do this. */
12ec0a8a 4750 if (simple_operand_p (lhs))
2c17ebb2 4751 return build2 (code == TRUTH_ANDIF_EXPR
fd96eeef 4752 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
2c17ebb2 4753 type, op0, op1);
90a73592 4754
fa8b888f 4755 else if (lang_hooks.decls.global_bindings_p () == 0
ce3fb06e 4756 && ! CONTAINS_PLACEHOLDER_P (lhs))
12ec0a8a 4757 {
4758 tree common = save_expr (lhs);
4759
2c17ebb2 4760 if (0 != (lhs = build_range_check (type, common,
12ec0a8a 4761 or_op ? ! in0_p : in0_p,
4762 low0, high0))
2c17ebb2 4763 && (0 != (rhs = build_range_check (type, common,
12ec0a8a 4764 or_op ? ! in1_p : in1_p,
4765 low1, high1))))
2c17ebb2 4766 return build2 (code == TRUTH_ANDIF_EXPR
fd96eeef 4767 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR,
2c17ebb2 4768 type, lhs, rhs);
12ec0a8a 4769 }
6f725368 4770 }
831e3af4 4771
831e3af4 4772 return 0;
6f725368 4773}
4774\f
94f29e88 4775/* Subroutine for fold_truthop: C is an INTEGER_CST interpreted as a P
b2dcfbf7 4776 bit value. Arrange things so the extra bits will be set to zero if and
2a6329ae 4777 only if C is signed-extended to its full width. If MASK is nonzero,
4778 it is an INTEGER_CST that should be AND'ed with the extra bits. */
94f29e88 4779
4780static tree
de1b648b 4781unextend (tree c, int p, int unsignedp, tree mask)
94f29e88 4782{
4783 tree type = TREE_TYPE (c);
4784 int modesize = GET_MODE_BITSIZE (TYPE_MODE (type));
4785 tree temp;
4786
4787 if (p == modesize || unsignedp)
4788 return c;
4789
94f29e88 4790 /* We work by getting just the sign bit into the low-order bit, then
c3418f42 4791 into the high-order bit, then sign-extend. We then XOR that value
94f29e88 4792 with C. */
4793 temp = const_binop (RSHIFT_EXPR, c, size_int (p - 1), 0);
4794 temp = const_binop (BIT_AND_EXPR, temp, size_int (1), 0);
dd5f6dae 4795
4796 /* We must use a signed type in order to get an arithmetic right shift.
4797 However, we must also avoid introducing accidental overflows, so that
cc049fa3 4798 a subsequent call to integer_zerop will work. Hence we must
dd5f6dae 4799 do the type conversion here. At this point, the constant is either
4800 zero or one, and the conversion to a signed type can never overflow.
4801 We could get an overflow if this conversion is done anywhere else. */
78a8ed03 4802 if (TYPE_UNSIGNED (type))
fa8b888f 4803 temp = fold_convert (lang_hooks.types.signed_type (type), temp);
dd5f6dae 4804
94f29e88 4805 temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
4806 temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
2a6329ae 4807 if (mask != 0)
b30e3dbc 4808 temp = const_binop (BIT_AND_EXPR, temp,
4809 fold_convert (TREE_TYPE (c), mask), 0);
dd5f6dae 4810 /* If necessary, convert the type back to match the type of C. */
78a8ed03 4811 if (TYPE_UNSIGNED (type))
b30e3dbc 4812 temp = fold_convert (type, temp);
2a6329ae 4813
b30e3dbc 4814 return fold_convert (type, const_binop (BIT_XOR_EXPR, c, temp, 0));
94f29e88 4815}
4816\f
79109eec 4817/* Find ways of folding logical expressions of LHS and RHS:
4818 Try to merge two comparisons to the same innermost item.
4819 Look for range tests like "ch >= '0' && ch <= '9'".
4820 Look for combinations of simple terms on machines with expensive branches
4821 and evaluate the RHS unconditionally.
2bc77e10 4822
4823 For example, if we have p->a == 2 && p->b == 4 and we can make an
4824 object large enough to span both A and B, we can do this with a comparison
4825 against the object ANDed with the a mask.
4826
4827 If we have p->a == q->a && p->b == q->b, we may be able to use bit masking
4828 operations to do this with one comparison.
4829
4830 We check for both normal comparisons and the BIT_AND_EXPRs made this by
4831 function and the one above.
4832
4833 CODE is the logical operation being done. It can be TRUTH_ANDIF_EXPR,
4834 TRUTH_AND_EXPR, TRUTH_ORIF_EXPR, or TRUTH_OR_EXPR.
4835
4836 TRUTH_TYPE is the type of the logical operand and LHS and RHS are its
4837 two operands.
4838
4839 We return the simplified tree or 0 if no optimization is possible. */
4840
4841static tree
de1b648b 4842fold_truthop (enum tree_code code, tree truth_type, tree lhs, tree rhs)
2bc77e10 4843{
62af9abe 4844 /* If this is the "or" of two comparisons, we can do something if
2bc77e10 4845 the comparisons are NE_EXPR. If this is the "and", we can do something
cc049fa3 4846 if the comparisons are EQ_EXPR. I.e.,
de1b648b 4847 (a->b == 2 && a->c == 4) can become (a->new == NEW).
2bc77e10 4848
4849 WANTED_CODE is this operation code. For single bit fields, we can
4850 convert EQ_EXPR to NE_EXPR so we need not reject the "wrong"
4851 comparison for one-bit fields. */
4852
79109eec 4853 enum tree_code wanted_code;
2bc77e10 4854 enum tree_code lcode, rcode;
79109eec 4855 tree ll_arg, lr_arg, rl_arg, rr_arg;
2bc77e10 4856 tree ll_inner, lr_inner, rl_inner, rr_inner;
02e7a332 4857 HOST_WIDE_INT ll_bitsize, ll_bitpos, lr_bitsize, lr_bitpos;
4858 HOST_WIDE_INT rl_bitsize, rl_bitpos, rr_bitsize, rr_bitpos;
4859 HOST_WIDE_INT xll_bitpos, xlr_bitpos, xrl_bitpos, xrr_bitpos;
4860 HOST_WIDE_INT lnbitsize, lnbitpos, rnbitsize, rnbitpos;
2bc77e10 4861 int ll_unsignedp, lr_unsignedp, rl_unsignedp, rr_unsignedp;
4862 enum machine_mode ll_mode, lr_mode, rl_mode, rr_mode;
4863 enum machine_mode lnmode, rnmode;
4864 tree ll_mask, lr_mask, rl_mask, rr_mask;
2a6329ae 4865 tree ll_and_mask, lr_and_mask, rl_and_mask, rr_and_mask;
79109eec 4866 tree l_const, r_const;
ffba564c 4867 tree lntype, rntype, result;
2bc77e10 4868 int first_bit, end_bit;
79109eec 4869 int volatilep;
40c3c1b3 4870 tree orig_lhs = lhs, orig_rhs = rhs;
4871 enum tree_code orig_code = code;
2bc77e10 4872
12ec0a8a 4873 /* Start by getting the comparison codes. Fail if anything is volatile.
4874 If one operand is a BIT_AND_EXPR with the constant one, treat it as if
4875 it were surrounded with a NE_EXPR. */
2bc77e10 4876
12ec0a8a 4877 if (TREE_SIDE_EFFECTS (lhs) || TREE_SIDE_EFFECTS (rhs))
79109eec 4878 return 0;
4879
2bc77e10 4880 lcode = TREE_CODE (lhs);
4881 rcode = TREE_CODE (rhs);
6f725368 4882
b5ab1edd 4883 if (lcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (lhs, 1)))
fd96eeef 4884 {
5c9198bd 4885 lhs = build2 (NE_EXPR, truth_type, lhs,
3c6185f1 4886 build_int_cst (TREE_TYPE (lhs), 0));
fd96eeef 4887 lcode = NE_EXPR;
4888 }
b5ab1edd 4889
4890 if (rcode == BIT_AND_EXPR && integer_onep (TREE_OPERAND (rhs, 1)))
fd96eeef 4891 {
5c9198bd 4892 rhs = build2 (NE_EXPR, truth_type, rhs,
3c6185f1 4893 build_int_cst (TREE_TYPE (rhs), 0));
fd96eeef 4894 rcode = NE_EXPR;
4895 }
b5ab1edd 4896
ce45a448 4897 if (TREE_CODE_CLASS (lcode) != tcc_comparison
4898 || TREE_CODE_CLASS (rcode) != tcc_comparison)
6f725368 4899 return 0;
4900
79109eec 4901 ll_arg = TREE_OPERAND (lhs, 0);
4902 lr_arg = TREE_OPERAND (lhs, 1);
4903 rl_arg = TREE_OPERAND (rhs, 0);
4904 rr_arg = TREE_OPERAND (rhs, 1);
cc049fa3 4905
7835f163 4906 /* Simplify (x<y) && (x==y) into (x<=y) and related optimizations. */
4907 if (simple_operand_p (ll_arg)
318a728f 4908 && simple_operand_p (lr_arg))
7835f163 4909 {
318a728f 4910 tree result;
7835f163 4911 if (operand_equal_p (ll_arg, rl_arg, 0)
4912 && operand_equal_p (lr_arg, rr_arg, 0))
318a728f 4913 {
4914 result = combine_comparisons (code, lcode, rcode,
4915 truth_type, ll_arg, lr_arg);
4916 if (result)
4917 return result;
4918 }
7835f163 4919 else if (operand_equal_p (ll_arg, rr_arg, 0)
4920 && operand_equal_p (lr_arg, rl_arg, 0))
318a728f 4921 {
4922 result = combine_comparisons (code, lcode,
4923 swap_tree_comparison (rcode),
4924 truth_type, ll_arg, lr_arg);
4925 if (result)
4926 return result;
4927 }
7835f163 4928 }
4929
318a728f 4930 code = ((code == TRUTH_AND_EXPR || code == TRUTH_ANDIF_EXPR)
4931 ? TRUTH_AND_EXPR : TRUTH_OR_EXPR);
4932
7735dddb 4933 /* If the RHS can be evaluated unconditionally and its operands are
79109eec 4934 simple, it wins to evaluate the RHS unconditionally on machines
4935 with expensive branches. In this case, this isn't a comparison
35212e61 4936 that can be merged. Avoid doing this if the RHS is a floating-point
4937 comparison since those can trap. */
79109eec 4938
4939 if (BRANCH_COST >= 2
35212e61 4940 && ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
79109eec 4941 && simple_operand_p (rl_arg)
7735dddb 4942 && simple_operand_p (rr_arg))
0425437e 4943 {
4944 /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
4945 if (code == TRUTH_OR_EXPR
4946 && lcode == NE_EXPR && integer_zerop (lr_arg)
4947 && rcode == NE_EXPR && integer_zerop (rr_arg)
4948 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
fd96eeef 4949 return build2 (NE_EXPR, truth_type,
4950 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4951 ll_arg, rl_arg),
3c6185f1 4952 build_int_cst (TREE_TYPE (ll_arg), 0));
0425437e 4953
4954 /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
4955 if (code == TRUTH_AND_EXPR
4956 && lcode == EQ_EXPR && integer_zerop (lr_arg)
4957 && rcode == EQ_EXPR && integer_zerop (rr_arg)
4958 && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
fd96eeef 4959 return build2 (EQ_EXPR, truth_type,
4960 build2 (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
4961 ll_arg, rl_arg),
3c6185f1 4962 build_int_cst (TREE_TYPE (ll_arg), 0));
0425437e 4963
17529f98 4964 if (LOGICAL_OP_NON_SHORT_CIRCUIT)
40c3c1b3 4965 {
4966 if (code != orig_code || lhs != orig_lhs || rhs != orig_rhs)
4967 return build2 (code, truth_type, lhs, rhs);
4968 return NULL_TREE;
4969 }
0425437e 4970 }
79109eec 4971
6f725368 4972 /* See if the comparisons can be merged. Then get all the parameters for
4973 each side. */
4974
2bc77e10 4975 if ((lcode != EQ_EXPR && lcode != NE_EXPR)
6f725368 4976 || (rcode != EQ_EXPR && rcode != NE_EXPR))
2bc77e10 4977 return 0;
4978
79109eec 4979 volatilep = 0;
4980 ll_inner = decode_field_reference (ll_arg,
2bc77e10 4981 &ll_bitsize, &ll_bitpos, &ll_mode,
2a6329ae 4982 &ll_unsignedp, &volatilep, &ll_mask,
4983 &ll_and_mask);
79109eec 4984 lr_inner = decode_field_reference (lr_arg,
2bc77e10 4985 &lr_bitsize, &lr_bitpos, &lr_mode,
2a6329ae 4986 &lr_unsignedp, &volatilep, &lr_mask,
4987 &lr_and_mask);
79109eec 4988 rl_inner = decode_field_reference (rl_arg,
2bc77e10 4989 &rl_bitsize, &rl_bitpos, &rl_mode,
2a6329ae 4990 &rl_unsignedp, &volatilep, &rl_mask,
4991 &rl_and_mask);
79109eec 4992 rr_inner = decode_field_reference (rr_arg,
2bc77e10 4993 &rr_bitsize, &rr_bitpos, &rr_mode,
2a6329ae 4994 &rr_unsignedp, &volatilep, &rr_mask,
4995 &rr_and_mask);
2bc77e10 4996
4997 /* It must be true that the inner operation on the lhs of each
4998 comparison must be the same if we are to be able to do anything.
4999 Then see if we have constants. If not, the same must be true for
5000 the rhs's. */
5001 if (volatilep || ll_inner == 0 || rl_inner == 0
5002 || ! operand_equal_p (ll_inner, rl_inner, 0))
5003 return 0;
5004
79109eec 5005 if (TREE_CODE (lr_arg) == INTEGER_CST
5006 && TREE_CODE (rr_arg) == INTEGER_CST)
5007 l_const = lr_arg, r_const = rr_arg;
2bc77e10 5008 else if (lr_inner == 0 || rr_inner == 0
5009 || ! operand_equal_p (lr_inner, rr_inner, 0))
5010 return 0;
79109eec 5011 else
5012 l_const = r_const = 0;
2bc77e10 5013
5014 /* If either comparison code is not correct for our logical operation,
5015 fail. However, we can convert a one-bit comparison against zero into
5016 the opposite comparison against that bit being set in the field. */
79109eec 5017
76e4a18b 5018 wanted_code = (code == TRUTH_AND_EXPR ? EQ_EXPR : NE_EXPR);
2bc77e10 5019 if (lcode != wanted_code)
5020 {
5021 if (l_const && integer_zerop (l_const) && integer_pow2p (ll_mask))
c6107ab0 5022 {
28bb328d 5023 /* Make the left operand unsigned, since we are only interested
5024 in the value of one bit. Otherwise we are doing the wrong
5025 thing below. */
5026 ll_unsignedp = 1;
68ae709d 5027 l_const = ll_mask;
c6107ab0 5028 }
2bc77e10 5029 else
5030 return 0;
5031 }
5032
68ae709d 5033 /* This is analogous to the code for l_const above. */
2bc77e10 5034 if (rcode != wanted_code)
5035 {
5036 if (r_const && integer_zerop (r_const) && integer_pow2p (rl_mask))
c6107ab0 5037 {
28bb328d 5038 rl_unsignedp = 1;
68ae709d 5039 r_const = rl_mask;
c6107ab0 5040 }
2bc77e10 5041 else
5042 return 0;
5043 }
5044
d50b22af 5045 /* After this point all optimizations will generate bit-field
5046 references, which we might not want. */
fa8b888f 5047 if (! lang_hooks.can_use_bit_fields_p ())
d50b22af 5048 return 0;
5049
2bc77e10 5050 /* See if we can find a mode that contains both fields being compared on
5051 the left. If we can't, fail. Otherwise, update all constants and masks
5052 to be relative to a field of that size. */
5053 first_bit = MIN (ll_bitpos, rl_bitpos);
5054 end_bit = MAX (ll_bitpos + ll_bitsize, rl_bitpos + rl_bitsize);
5055 lnmode = get_best_mode (end_bit - first_bit, first_bit,
5056 TYPE_ALIGN (TREE_TYPE (ll_inner)), word_mode,
5057 volatilep);
5058 if (lnmode == VOIDmode)
5059 return 0;
5060
5061 lnbitsize = GET_MODE_BITSIZE (lnmode);
5062 lnbitpos = first_bit & ~ (lnbitsize - 1);
fa8b888f 5063 lntype = lang_hooks.types.type_for_size (lnbitsize, 1);
2bc77e10 5064 xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
5065
51356f86 5066 if (BYTES_BIG_ENDIAN)
5067 {
5068 xll_bitpos = lnbitsize - xll_bitpos - ll_bitsize;
5069 xrl_bitpos = lnbitsize - xrl_bitpos - rl_bitsize;
5070 }
2bc77e10 5071
b30e3dbc 5072 ll_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, ll_mask),
5485823f 5073 size_int (xll_bitpos), 0);
b30e3dbc 5074 rl_mask = const_binop (LSHIFT_EXPR, fold_convert (lntype, rl_mask),
5485823f 5075 size_int (xrl_bitpos), 0);
2bc77e10 5076
2bc77e10 5077 if (l_const)
5078 {
b30e3dbc 5079 l_const = fold_convert (lntype, l_const);
cc049fa3 5080 l_const = unextend (l_const, ll_bitsize, ll_unsignedp, ll_and_mask);
94f29e88 5081 l_const = const_binop (LSHIFT_EXPR, l_const, size_int (xll_bitpos), 0);
5082 if (! integer_zerop (const_binop (BIT_AND_EXPR, l_const,
7ab7fd4f 5083 fold_build1 (BIT_NOT_EXPR,
5084 lntype, ll_mask),
94f29e88 5085 0)))
5086 {
c3ceba8e 5087 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
cc049fa3 5088
20783f07 5089 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
94f29e88 5090 }
2bc77e10 5091 }
5092 if (r_const)
5093 {
b30e3dbc 5094 r_const = fold_convert (lntype, r_const);
2a6329ae 5095 r_const = unextend (r_const, rl_bitsize, rl_unsignedp, rl_and_mask);
94f29e88 5096 r_const = const_binop (LSHIFT_EXPR, r_const, size_int (xrl_bitpos), 0);
5097 if (! integer_zerop (const_binop (BIT_AND_EXPR, r_const,
7ab7fd4f 5098 fold_build1 (BIT_NOT_EXPR,
5099 lntype, rl_mask),
94f29e88 5100 0)))
5101 {
c3ceba8e 5102 warning (0, "comparison is always %d", wanted_code == NE_EXPR);
be2828ce 5103
20783f07 5104 return constant_boolean_node (wanted_code == NE_EXPR, truth_type);
94f29e88 5105 }
2bc77e10 5106 }
5107
5108 /* If the right sides are not constant, do the same for it. Also,
5109 disallow this optimization if a size or signedness mismatch occurs
5110 between the left and right sides. */
5111 if (l_const == 0)
5112 {
5113 if (ll_bitsize != lr_bitsize || rl_bitsize != rr_bitsize
15e4fe21 5114 || ll_unsignedp != lr_unsignedp || rl_unsignedp != rr_unsignedp
5115 /* Make sure the two fields on the right
5116 correspond to the left without being swapped. */
5117 || ll_bitpos - rl_bitpos != lr_bitpos - rr_bitpos)
2bc77e10 5118 return 0;
5119
5120 first_bit = MIN (lr_bitpos, rr_bitpos);
5121 end_bit = MAX (lr_bitpos + lr_bitsize, rr_bitpos + rr_bitsize);
5122 rnmode = get_best_mode (end_bit - first_bit, first_bit,
5123 TYPE_ALIGN (TREE_TYPE (lr_inner)), word_mode,
5124 volatilep);
5125 if (rnmode == VOIDmode)
5126 return 0;
5127
5128 rnbitsize = GET_MODE_BITSIZE (rnmode);
5129 rnbitpos = first_bit & ~ (rnbitsize - 1);
fa8b888f 5130 rntype = lang_hooks.types.type_for_size (rnbitsize, 1);
2bc77e10 5131 xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
5132
51356f86 5133 if (BYTES_BIG_ENDIAN)
5134 {
5135 xlr_bitpos = rnbitsize - xlr_bitpos - lr_bitsize;
5136 xrr_bitpos = rnbitsize - xrr_bitpos - rr_bitsize;
5137 }
2bc77e10 5138
b30e3dbc 5139 lr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, lr_mask),
5485823f 5140 size_int (xlr_bitpos), 0);
b30e3dbc 5141 rr_mask = const_binop (LSHIFT_EXPR, fold_convert (rntype, rr_mask),
5485823f 5142 size_int (xrr_bitpos), 0);
2bc77e10 5143
5144 /* Make a mask that corresponds to both fields being compared.
00ee0921 5145 Do this for both items being compared. If the operands are the
5146 same size and the bits being compared are in the same position
5147 then we can do this by masking both and comparing the masked
5148 results. */
5485823f 5149 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
5150 lr_mask = const_binop (BIT_IOR_EXPR, lr_mask, rr_mask, 0);
00ee0921 5151 if (lnbitsize == rnbitsize && xll_bitpos == xlr_bitpos)
2bc77e10 5152 {
ffba564c 5153 lhs = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
2bc77e10 5154 ll_unsignedp || rl_unsignedp);
00ee0921 5155 if (! all_ones_mask_p (ll_mask, lnbitsize))
fd96eeef 5156 lhs = build2 (BIT_AND_EXPR, lntype, lhs, ll_mask);
00ee0921 5157
ffba564c 5158 rhs = make_bit_field_ref (lr_inner, rntype, rnbitsize, rnbitpos,
2bc77e10 5159 lr_unsignedp || rr_unsignedp);
00ee0921 5160 if (! all_ones_mask_p (lr_mask, rnbitsize))
fd96eeef 5161 rhs = build2 (BIT_AND_EXPR, rntype, rhs, lr_mask);
00ee0921 5162
fd96eeef 5163 return build2 (wanted_code, truth_type, lhs, rhs);
2bc77e10 5164 }
5165
5166 /* There is still another way we can do something: If both pairs of
5167 fields being compared are adjacent, we may be able to make a wider
4cf66b97 5168 field containing them both.
5169
5170 Note that we still must mask the lhs/rhs expressions. Furthermore,
cc049fa3 5171 the mask must be shifted to account for the shift done by
4cf66b97 5172 make_bit_field_ref. */
2bc77e10 5173 if ((ll_bitsize + ll_bitpos == rl_bitpos
5174 && lr_bitsize + lr_bitpos == rr_bitpos)
5175 || (ll_bitpos == rl_bitpos + rl_bitsize
5176 && lr_bitpos == rr_bitpos + rr_bitsize))
4cf66b97 5177 {
ffba564c 5178 tree type;
5179
5180 lhs = make_bit_field_ref (ll_inner, lntype, ll_bitsize + rl_bitsize,
4cf66b97 5181 MIN (ll_bitpos, rl_bitpos), ll_unsignedp);
ffba564c 5182 rhs = make_bit_field_ref (lr_inner, rntype, lr_bitsize + rr_bitsize,
5183 MIN (lr_bitpos, rr_bitpos), lr_unsignedp);
5184
4cf66b97 5185 ll_mask = const_binop (RSHIFT_EXPR, ll_mask,
5186 size_int (MIN (xll_bitpos, xrl_bitpos)), 0);
ffba564c 5187 lr_mask = const_binop (RSHIFT_EXPR, lr_mask,
5188 size_int (MIN (xlr_bitpos, xrr_bitpos)), 0);
5189
5190 /* Convert to the smaller type before masking out unwanted bits. */
5191 type = lntype;
5192 if (lntype != rntype)
5193 {
5194 if (lnbitsize > rnbitsize)
5195 {
b30e3dbc 5196 lhs = fold_convert (rntype, lhs);
5197 ll_mask = fold_convert (rntype, ll_mask);
ffba564c 5198 type = rntype;
5199 }
5200 else if (lnbitsize < rnbitsize)
5201 {
b30e3dbc 5202 rhs = fold_convert (lntype, rhs);
5203 lr_mask = fold_convert (lntype, lr_mask);
ffba564c 5204 type = lntype;
5205 }
5206 }
5207
4cf66b97 5208 if (! all_ones_mask_p (ll_mask, ll_bitsize + rl_bitsize))
fd96eeef 5209 lhs = build2 (BIT_AND_EXPR, type, lhs, ll_mask);
4cf66b97 5210
4cf66b97 5211 if (! all_ones_mask_p (lr_mask, lr_bitsize + rr_bitsize))
fd96eeef 5212 rhs = build2 (BIT_AND_EXPR, type, rhs, lr_mask);
4cf66b97 5213
fd96eeef 5214 return build2 (wanted_code, truth_type, lhs, rhs);
4cf66b97 5215 }
2bc77e10 5216
5217 return 0;
5218 }
5219
5220 /* Handle the case of comparisons with constants. If there is something in
5221 common between the masks, those bits of the constants must be the same.
5222 If not, the condition is always false. Test for this to avoid generating
5223 incorrect code below. */
5485823f 5224 result = const_binop (BIT_AND_EXPR, ll_mask, rl_mask, 0);
2bc77e10 5225 if (! integer_zerop (result)
5485823f 5226 && simple_cst_equal (const_binop (BIT_AND_EXPR, result, l_const, 0),
5227 const_binop (BIT_AND_EXPR, result, r_const, 0)) != 1)
2bc77e10 5228 {
5229 if (wanted_code == NE_EXPR)
5230 {
c3ceba8e 5231 warning (0, "%<or%> of unmatched not-equal tests is always 1");
20783f07 5232 return constant_boolean_node (true, truth_type);
2bc77e10 5233 }
5234 else
5235 {
c3ceba8e 5236 warning (0, "%<and%> of mutually exclusive equal-tests is always 0");
20783f07 5237 return constant_boolean_node (false, truth_type);
2bc77e10 5238 }
5239 }
5240
5241 /* Construct the expression we will return. First get the component
5242 reference we will make. Unless the mask is all ones the width of
5243 that field, perform the mask operation. Then compare with the
5244 merged constant. */
ffba564c 5245 result = make_bit_field_ref (ll_inner, lntype, lnbitsize, lnbitpos,
2bc77e10 5246 ll_unsignedp || rl_unsignedp);
5247
5485823f 5248 ll_mask = const_binop (BIT_IOR_EXPR, ll_mask, rl_mask, 0);
2bc77e10 5249 if (! all_ones_mask_p (ll_mask, lnbitsize))
fd96eeef 5250 result = build2 (BIT_AND_EXPR, lntype, result, ll_mask);
2bc77e10 5251
fd96eeef 5252 return build2 (wanted_code, truth_type, result,
5253 const_binop (BIT_IOR_EXPR, l_const, r_const, 0));
2bc77e10 5254}
5255\f
cc049fa3 5256/* Optimize T, which is a comparison of a MIN_EXPR or MAX_EXPR with a
155b05dc 5257 constant. */
5258
5259static tree
155acab4 5260optimize_minmax_comparison (enum tree_code code, tree type, tree op0, tree op1)
155b05dc 5261{
155acab4 5262 tree arg0 = op0;
155b05dc 5263 enum tree_code op_code;
155acab4 5264 tree comp_const = op1;
155b05dc 5265 tree minmax_const;
5266 int consts_equal, consts_lt;
5267 tree inner;
5268
5269 STRIP_SIGN_NOPS (arg0);
5270
5271 op_code = TREE_CODE (arg0);
5272 minmax_const = TREE_OPERAND (arg0, 1);
5273 consts_equal = tree_int_cst_equal (minmax_const, comp_const);
5274 consts_lt = tree_int_cst_lt (minmax_const, comp_const);
5275 inner = TREE_OPERAND (arg0, 0);
5276
5277 /* If something does not permit us to optimize, return the original tree. */
5278 if ((op_code != MIN_EXPR && op_code != MAX_EXPR)
5279 || TREE_CODE (comp_const) != INTEGER_CST
5280 || TREE_CONSTANT_OVERFLOW (comp_const)
5281 || TREE_CODE (minmax_const) != INTEGER_CST
5282 || TREE_CONSTANT_OVERFLOW (minmax_const))
155acab4 5283 return NULL_TREE;
155b05dc 5284
5285 /* Now handle all the various comparison codes. We only handle EQ_EXPR
5286 and GT_EXPR, doing the rest with recursive calls using logical
5287 simplifications. */
155acab4 5288 switch (code)
155b05dc 5289 {
5290 case NE_EXPR: case LT_EXPR: case LE_EXPR:
155acab4 5291 {
6758b11c 5292 tree tem = optimize_minmax_comparison (invert_tree_comparison (code, false),
5293 type, op0, op1);
5294 if (tem)
5295 return invert_truthvalue (tem);
5296 return NULL_TREE;
155acab4 5297 }
155b05dc 5298
5299 case GE_EXPR:
5300 return
7ab7fd4f 5301 fold_build2 (TRUTH_ORIF_EXPR, type,
5302 optimize_minmax_comparison
5303 (EQ_EXPR, type, arg0, comp_const),
5304 optimize_minmax_comparison
5305 (GT_EXPR, type, arg0, comp_const));
155b05dc 5306
5307 case EQ_EXPR:
5308 if (op_code == MAX_EXPR && consts_equal)
5309 /* MAX (X, 0) == 0 -> X <= 0 */
7ab7fd4f 5310 return fold_build2 (LE_EXPR, type, inner, comp_const);
155b05dc 5311
5312 else if (op_code == MAX_EXPR && consts_lt)
5313 /* MAX (X, 0) == 5 -> X == 5 */
7ab7fd4f 5314 return fold_build2 (EQ_EXPR, type, inner, comp_const);
155b05dc 5315
5316 else if (op_code == MAX_EXPR)
5317 /* MAX (X, 0) == -1 -> false */
5318 return omit_one_operand (type, integer_zero_node, inner);
5319
5320 else if (consts_equal)
5321 /* MIN (X, 0) == 0 -> X >= 0 */
7ab7fd4f 5322 return fold_build2 (GE_EXPR, type, inner, comp_const);
155b05dc 5323
5324 else if (consts_lt)
5325 /* MIN (X, 0) == 5 -> false */
5326 return omit_one_operand (type, integer_zero_node, inner);
5327
5328 else
5329 /* MIN (X, 0) == -1 -> X == -1 */
7ab7fd4f 5330 return fold_build2 (EQ_EXPR, type, inner, comp_const);
155b05dc 5331
5332 case GT_EXPR:
5333 if (op_code == MAX_EXPR && (consts_equal || consts_lt))
5334 /* MAX (X, 0) > 0 -> X > 0
5335 MAX (X, 0) > 5 -> X > 5 */
7ab7fd4f 5336 return fold_build2 (GT_EXPR, type, inner, comp_const);
155b05dc 5337
5338 else if (op_code == MAX_EXPR)
5339 /* MAX (X, 0) > -1 -> true */
5340 return omit_one_operand (type, integer_one_node, inner);
5341
5342 else if (op_code == MIN_EXPR && (consts_equal || consts_lt))
5343 /* MIN (X, 0) > 0 -> false
5344 MIN (X, 0) > 5 -> false */
5345 return omit_one_operand (type, integer_zero_node, inner);
5346
5347 else
5348 /* MIN (X, 0) > -1 -> X > -1 */
7ab7fd4f 5349 return fold_build2 (GT_EXPR, type, inner, comp_const);
155b05dc 5350
5351 default:
155acab4 5352 return NULL_TREE;
155b05dc 5353 }
5354}
5355\f
23ec2d5e 5356/* T is an integer expression that is being multiplied, divided, or taken a
5357 modulus (CODE says which and what kind of divide or modulus) by a
5358 constant C. See if we can eliminate that operation by folding it with
5359 other operations already in T. WIDE_TYPE, if non-null, is a type that
5360 should be used for the computation if wider than our type.
5361
b07ba9ff 5362 For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
5363 (X * 2) + (Y * 4). We must, however, be assured that either the original
2f5cf552 5364 expression would not overflow or that overflow is undefined for the type
5365 in the language in question.
5366
5367 We also canonicalize (X + 7) * 4 into X * 4 + 28 in the hope that either
5368 the machine has a multiply-accumulate insn or that this is part of an
5369 addressing calculation.
23ec2d5e 5370
5371 If we return a non-null expression, it is an equivalent form of the
5372 original computation, but need not be in the original type. */
5373
5374static tree
de1b648b 5375extract_muldiv (tree t, tree c, enum tree_code code, tree wide_type)
009f6e1c 5376{
5377 /* To avoid exponential search depth, refuse to allow recursion past
5378 three levels. Beyond that (1) it's highly unlikely that we'll find
5379 something interesting and (2) we've probably processed it before
5380 when we built the inner expression. */
5381
5382 static int depth;
5383 tree ret;
5384
5385 if (depth > 3)
5386 return NULL;
5387
5388 depth++;
5389 ret = extract_muldiv_1 (t, c, code, wide_type);
5390 depth--;
5391
5392 return ret;
5393}
5394
5395static tree
de1b648b 5396extract_muldiv_1 (tree t, tree c, enum tree_code code, tree wide_type)
23ec2d5e 5397{
5398 tree type = TREE_TYPE (t);
5399 enum tree_code tcode = TREE_CODE (t);
cc049fa3 5400 tree ctype = (wide_type != 0 && (GET_MODE_SIZE (TYPE_MODE (wide_type))
23ec2d5e 5401 > GET_MODE_SIZE (TYPE_MODE (type)))
5402 ? wide_type : type);
5403 tree t1, t2;
5404 int same_p = tcode == code;
03435587 5405 tree op0 = NULL_TREE, op1 = NULL_TREE;
23ec2d5e 5406
5407 /* Don't deal with constants of zero here; they confuse the code below. */
5408 if (integer_zerop (c))
2f5cf552 5409 return NULL_TREE;
23ec2d5e 5410
ce45a448 5411 if (TREE_CODE_CLASS (tcode) == tcc_unary)
23ec2d5e 5412 op0 = TREE_OPERAND (t, 0);
5413
ce45a448 5414 if (TREE_CODE_CLASS (tcode) == tcc_binary)
23ec2d5e 5415 op0 = TREE_OPERAND (t, 0), op1 = TREE_OPERAND (t, 1);
5416
5417 /* Note that we need not handle conditional operations here since fold
5418 already handles those cases. So just do arithmetic here. */
5419 switch (tcode)
5420 {
5421 case INTEGER_CST:
5422 /* For a constant, we can always simplify if we are a multiply
5423 or (for divide and modulus) if it is a multiple of our constant. */
5424 if (code == MULT_EXPR
5425 || integer_zerop (const_binop (TRUNC_MOD_EXPR, t, c, 0)))
b30e3dbc 5426 return const_binop (code, fold_convert (ctype, t),
5427 fold_convert (ctype, c), 0);
23ec2d5e 5428 break;
5429
5430 case CONVERT_EXPR: case NON_LVALUE_EXPR: case NOP_EXPR:
12480406 5431 /* If op0 is an expression ... */
ce45a448 5432 if ((COMPARISON_CLASS_P (op0)
5433 || UNARY_CLASS_P (op0)
5434 || BINARY_CLASS_P (op0)
5435 || EXPRESSION_CLASS_P (op0))
12480406 5436 /* ... and is unsigned, and its type is smaller than ctype,
5437 then we cannot pass through as widening. */
78a8ed03 5438 && ((TYPE_UNSIGNED (TREE_TYPE (op0))
12480406 5439 && ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
5440 && TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
5441 && (GET_MODE_SIZE (TYPE_MODE (ctype))
5442 > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
40309554 5443 /* ... or this is a truncation (t is narrower than op0),
5444 then we cannot pass through this narrowing. */
5445 || (GET_MODE_SIZE (TYPE_MODE (type))
cee280ef 5446 < GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0))))
5447 /* ... or signedness changes for division or modulus,
5448 then we cannot pass through this conversion. */
5449 || (code != MULT_EXPR
78a8ed03 5450 && (TYPE_UNSIGNED (ctype)
5451 != TYPE_UNSIGNED (TREE_TYPE (op0))))))
3cb1a3c6 5452 break;
5453
23ec2d5e 5454 /* Pass the constant down and see if we can make a simplification. If
5f0002b0 5455 we can, replace this expression with the inner simplification for
5456 possible later conversion to our or some other type. */
b30e3dbc 5457 if ((t2 = fold_convert (TREE_TYPE (op0), c)) != 0
f2fa1510 5458 && TREE_CODE (t2) == INTEGER_CST
5459 && ! TREE_CONSTANT_OVERFLOW (t2)
5460 && (0 != (t1 = extract_muldiv (op0, t2, code,
5461 code == MULT_EXPR
5462 ? ctype : NULL_TREE))))
23ec2d5e 5463 return t1;
5464 break;
5465
24877233 5466 case ABS_EXPR:
5467 /* If widening the type changes it from signed to unsigned, then we
5468 must avoid building ABS_EXPR itself as unsigned. */
5469 if (TYPE_UNSIGNED (ctype) && !TYPE_UNSIGNED (type))
5470 {
5471 tree cstype = (*lang_hooks.types.signed_type) (ctype);
5472 if ((t1 = extract_muldiv (op0, c, code, cstype)) != 0)
5473 {
7ab7fd4f 5474 t1 = fold_build1 (tcode, cstype, fold_convert (cstype, t1));
24877233 5475 return fold_convert (ctype, t1);
5476 }
5477 break;
5478 }
5479 /* FALLTHROUGH */
5480 case NEGATE_EXPR:
23ec2d5e 5481 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
7ab7fd4f 5482 return fold_build1 (tcode, ctype, fold_convert (ctype, t1));
23ec2d5e 5483 break;
5484
5485 case MIN_EXPR: case MAX_EXPR:
6269027b 5486 /* If widening the type changes the signedness, then we can't perform
5487 this optimization as that changes the result. */
78a8ed03 5488 if (TYPE_UNSIGNED (ctype) != TYPE_UNSIGNED (type))
6269027b 5489 break;
5490
23ec2d5e 5491 /* MIN (a, b) / 5 -> MIN (a / 5, b / 5) */
5492 if ((t1 = extract_muldiv (op0, c, code, wide_type)) != 0
5493 && (t2 = extract_muldiv (op1, c, code, wide_type)) != 0)
5f0002b0 5494 {
5495 if (tree_int_cst_sgn (c) < 0)
5496 tcode = (tcode == MIN_EXPR ? MAX_EXPR : MIN_EXPR);
5497
7ab7fd4f 5498 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5499 fold_convert (ctype, t2));
5f0002b0 5500 }
23ec2d5e 5501 break;
5502
23ec2d5e 5503 case LSHIFT_EXPR: case RSHIFT_EXPR:
5504 /* If the second operand is constant, this is a multiplication
5505 or floor division, by a power of two, so we can treat it that
dceee6fb 5506 way unless the multiplier or divisor overflows. Signed
5507 left-shift overflow is implementation-defined rather than
5508 undefined in C90, so do not convert signed left shift into
5509 multiplication. */
23ec2d5e 5510 if (TREE_CODE (op1) == INTEGER_CST
dceee6fb 5511 && (tcode == RSHIFT_EXPR || TYPE_UNSIGNED (TREE_TYPE (op0)))
c011f821 5512 /* const_binop may not detect overflow correctly,
5513 so check for it explicitly here. */
5514 && TYPE_PRECISION (TREE_TYPE (size_one_node)) > TREE_INT_CST_LOW (op1)
5515 && TREE_INT_CST_HIGH (op1) == 0
b30e3dbc 5516 && 0 != (t1 = fold_convert (ctype,
5517 const_binop (LSHIFT_EXPR,
5518 size_one_node,
5519 op1, 0)))
23ec2d5e 5520 && ! TREE_OVERFLOW (t1))
fd96eeef 5521 return extract_muldiv (build2 (tcode == LSHIFT_EXPR
5522 ? MULT_EXPR : FLOOR_DIV_EXPR,
5523 ctype, fold_convert (ctype, op0), t1),
23ec2d5e 5524 c, code, wide_type);
5525 break;
5526
5527 case PLUS_EXPR: case MINUS_EXPR:
5528 /* See if we can eliminate the operation on both sides. If we can, we
5529 can return a new PLUS or MINUS. If we can't, the only remaining
5530 cases where we can do anything are if the second operand is a
5531 constant. */
5532 t1 = extract_muldiv (op0, c, code, wide_type);
5533 t2 = extract_muldiv (op1, c, code, wide_type);
17e3940f 5534 if (t1 != 0 && t2 != 0
5535 && (code == MULT_EXPR
e5b30d78 5536 /* If not multiplication, we can only do this if both operands
5537 are divisible by c. */
5538 || (multiple_of_p (ctype, op0, c)
5539 && multiple_of_p (ctype, op1, c))))
7ab7fd4f 5540 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5541 fold_convert (ctype, t2));
23ec2d5e 5542
5f0002b0 5543 /* If this was a subtraction, negate OP1 and set it to be an addition.
5544 This simplifies the logic below. */
5545 if (tcode == MINUS_EXPR)
5546 tcode = PLUS_EXPR, op1 = negate_expr (op1);
5547
ec4d93b0 5548 if (TREE_CODE (op1) != INTEGER_CST)
5549 break;
5550
5f0002b0 5551 /* If either OP1 or C are negative, this optimization is not safe for
5552 some of the division and remainder types while for others we need
5553 to change the code. */
5554 if (tree_int_cst_sgn (op1) < 0 || tree_int_cst_sgn (c) < 0)
5555 {
5556 if (code == CEIL_DIV_EXPR)
5557 code = FLOOR_DIV_EXPR;
5f0002b0 5558 else if (code == FLOOR_DIV_EXPR)
5559 code = CEIL_DIV_EXPR;
b575bb01 5560 else if (code != MULT_EXPR
5561 && code != CEIL_MOD_EXPR && code != FLOOR_MOD_EXPR)
5f0002b0 5562 break;
5563 }
5564
98248b34 5565 /* If it's a multiply or a division/modulus operation of a multiple
5566 of our constant, do the operation and verify it doesn't overflow. */
5567 if (code == MULT_EXPR
5568 || integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
d3371fcd 5569 {
b30e3dbc 5570 op1 = const_binop (code, fold_convert (ctype, op1),
5571 fold_convert (ctype, c), 0);
f5c47dd7 5572 /* We allow the constant to overflow with wrapping semantics. */
5573 if (op1 == 0
5574 || (TREE_OVERFLOW (op1) && ! flag_wrapv))
d3371fcd 5575 break;
5576 }
98248b34 5577 else
d3371fcd 5578 break;
5f0002b0 5579
fc452262 5580 /* If we have an unsigned type is not a sizetype, we cannot widen
5581 the operation since it will change the result if the original
5582 computation overflowed. */
78a8ed03 5583 if (TYPE_UNSIGNED (ctype)
d490e2f2 5584 && ! (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype))
fc452262 5585 && ctype != type)
5586 break;
5587
23ec2d5e 5588 /* If we were able to eliminate our operation from the first side,
5f0002b0 5589 apply our operation to the second side and reform the PLUS. */
5590 if (t1 != 0 && (TREE_CODE (t1) != code || code == MULT_EXPR))
7ab7fd4f 5591 return fold_build2 (tcode, ctype, fold_convert (ctype, t1), op1);
23ec2d5e 5592
5593 /* The last case is if we are a multiply. In that case, we can
5594 apply the distributive law to commute the multiply and addition
6312a35e 5595 if the multiplication of the constants doesn't overflow. */
5f0002b0 5596 if (code == MULT_EXPR)
7ab7fd4f 5597 return fold_build2 (tcode, ctype,
5598 fold_build2 (code, ctype,
5599 fold_convert (ctype, op0),
5600 fold_convert (ctype, c)),
5601 op1);
23ec2d5e 5602
5603 break;
5604
5605 case MULT_EXPR:
5606 /* We have a special case here if we are doing something like
5607 (C * 8) % 4 since we know that's zero. */
5608 if ((code == TRUNC_MOD_EXPR || code == CEIL_MOD_EXPR
5609 || code == FLOOR_MOD_EXPR || code == ROUND_MOD_EXPR)
5610 && TREE_CODE (TREE_OPERAND (t, 1)) == INTEGER_CST
5611 && integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
5612 return omit_one_operand (type, integer_zero_node, op0);
5613
6312a35e 5614 /* ... fall through ... */
23ec2d5e 5615
5616 case TRUNC_DIV_EXPR: case CEIL_DIV_EXPR: case FLOOR_DIV_EXPR:
5617 case ROUND_DIV_EXPR: case EXACT_DIV_EXPR:
5618 /* If we can extract our operation from the LHS, do so and return a
5619 new operation. Likewise for the RHS from a MULT_EXPR. Otherwise,
5620 do something only if the second operand is a constant. */
5621 if (same_p
5622 && (t1 = extract_muldiv (op0, c, code, wide_type)) != 0)
7ab7fd4f 5623 return fold_build2 (tcode, ctype, fold_convert (ctype, t1),
5624 fold_convert (ctype, op1));
23ec2d5e 5625 else if (tcode == MULT_EXPR && code == MULT_EXPR
5626 && (t1 = extract_muldiv (op1, c, code, wide_type)) != 0)
7ab7fd4f 5627 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5628 fold_convert (ctype, t1));
23ec2d5e 5629 else if (TREE_CODE (op1) != INTEGER_CST)
5630 return 0;
5631
5632 /* If these are the same operation types, we can associate them
5633 assuming no overflow. */
5634 if (tcode == code
b30e3dbc 5635 && 0 != (t1 = const_binop (MULT_EXPR, fold_convert (ctype, op1),
5636 fold_convert (ctype, c), 0))
23ec2d5e 5637 && ! TREE_OVERFLOW (t1))
7ab7fd4f 5638 return fold_build2 (tcode, ctype, fold_convert (ctype, op0), t1);
23ec2d5e 5639
5640 /* If these operations "cancel" each other, we have the main
5641 optimizations of this pass, which occur when either constant is a
5642 multiple of the other, in which case we replace this with either an
cc049fa3 5643 operation or CODE or TCODE.
2f5cf552 5644
35a3065a 5645 If we have an unsigned type that is not a sizetype, we cannot do
2f5cf552 5646 this since it will change the result if the original computation
5647 overflowed. */
78a8ed03 5648 if ((! TYPE_UNSIGNED (ctype)
d490e2f2 5649 || (TREE_CODE (ctype) == INTEGER_TYPE && TYPE_IS_SIZETYPE (ctype)))
b24bee03 5650 && ! flag_wrapv
2f5cf552 5651 && ((code == MULT_EXPR && tcode == EXACT_DIV_EXPR)
5652 || (tcode == MULT_EXPR
5653 && code != TRUNC_MOD_EXPR && code != CEIL_MOD_EXPR
5654 && code != FLOOR_MOD_EXPR && code != ROUND_MOD_EXPR)))
23ec2d5e 5655 {
5656 if (integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
7ab7fd4f 5657 return fold_build2 (tcode, ctype, fold_convert (ctype, op0),
5658 fold_convert (ctype,
5659 const_binop (TRUNC_DIV_EXPR,
5660 op1, c, 0)));
23ec2d5e 5661 else if (integer_zerop (const_binop (TRUNC_MOD_EXPR, c, op1, 0)))
7ab7fd4f 5662 return fold_build2 (code, ctype, fold_convert (ctype, op0),
5663 fold_convert (ctype,
5664 const_binop (TRUNC_DIV_EXPR,
5665 c, op1, 0)));
23ec2d5e 5666 }
5667 break;
5668
5669 default:
5670 break;
5671 }
5672
5673 return 0;
5674}
5675\f
b4af30fd 5676/* Return a node which has the indicated constant VALUE (either 0 or
5677 1), and is of the indicated TYPE. */
5678
5c9198bd 5679tree
de1b648b 5680constant_boolean_node (int value, tree type)
b4af30fd 5681{
5682 if (type == integer_type_node)
5683 return value ? integer_one_node : integer_zero_node;
c4e122e7 5684 else if (type == boolean_type_node)
5685 return value ? boolean_true_node : boolean_false_node;
cc049fa3 5686 else
7016c612 5687 return build_int_cst (type, value);
b4af30fd 5688}
5689
6d24c9aa 5690
5691/* Return true if expr looks like an ARRAY_REF and set base and
5692 offset to the appropriate trees. If there is no offset,
6252c281 5693 offset is set to NULL_TREE. Base will be canonicalized to
5694 something you can get the element type from using
148ad152 5695 TREE_TYPE (TREE_TYPE (base)). Offset will be the offset
5696 in bytes to the base. */
6d24c9aa 5697
5698static bool
5699extract_array_ref (tree expr, tree *base, tree *offset)
5700{
6d24c9aa 5701 /* One canonical form is a PLUS_EXPR with the first
5702 argument being an ADDR_EXPR with a possible NOP_EXPR
5703 attached. */
5704 if (TREE_CODE (expr) == PLUS_EXPR)
5705 {
5706 tree op0 = TREE_OPERAND (expr, 0);
6252c281 5707 tree inner_base, dummy1;
5708 /* Strip NOP_EXPRs here because the C frontends and/or
5709 folders present us (int *)&x.a + 4B possibly. */
6d24c9aa 5710 STRIP_NOPS (op0);
6252c281 5711 if (extract_array_ref (op0, &inner_base, &dummy1))
6d24c9aa 5712 {
6252c281 5713 *base = inner_base;
5714 if (dummy1 == NULL_TREE)
5715 *offset = TREE_OPERAND (expr, 1);
5716 else
5717 *offset = fold_build2 (PLUS_EXPR, TREE_TYPE (expr),
5718 dummy1, TREE_OPERAND (expr, 1));
6d24c9aa 5719 return true;
5720 }
5721 }
5722 /* Other canonical form is an ADDR_EXPR of an ARRAY_REF,
5723 which we transform into an ADDR_EXPR with appropriate
5724 offset. For other arguments to the ADDR_EXPR we assume
5725 zero offset and as such do not care about the ADDR_EXPR
5726 type and strip possible nops from it. */
6252c281 5727 else if (TREE_CODE (expr) == ADDR_EXPR)
6d24c9aa 5728 {
6252c281 5729 tree op0 = TREE_OPERAND (expr, 0);
6d24c9aa 5730 if (TREE_CODE (op0) == ARRAY_REF)
5731 {
148ad152 5732 tree idx = TREE_OPERAND (op0, 1);
6252c281 5733 *base = TREE_OPERAND (op0, 0);
148ad152 5734 *offset = fold_build2 (MULT_EXPR, TREE_TYPE (idx), idx,
5735 array_ref_element_size (op0));
6d24c9aa 5736 }
5737 else
5738 {
6252c281 5739 /* Handle array-to-pointer decay as &a. */
5740 if (TREE_CODE (TREE_TYPE (op0)) == ARRAY_TYPE)
5741 *base = TREE_OPERAND (expr, 0);
5742 else
5743 *base = expr;
6d24c9aa 5744 *offset = NULL_TREE;
5745 }
5746 return true;
5747 }
6252c281 5748 /* The next canonical form is a VAR_DECL with POINTER_TYPE. */
5749 else if (SSA_VAR_P (expr)
5750 && TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE)
5751 {
5752 *base = expr;
5753 *offset = NULL_TREE;
5754 return true;
5755 }
6d24c9aa 5756
5757 return false;
5758}
5759
5760
203a24c4 5761/* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
47cbd05d 5762 Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
5763 CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
6ef828f9 5764 expression, and ARG to `a'. If COND_FIRST_P is nonzero, then the
47cbd05d 5765 COND is the first argument to CODE; otherwise (as in the example
5766 given here), it is the second argument. TYPE is the type of the
9c9bad97 5767 original expression. Return NULL_TREE if no simplification is
a6661800 5768 possible. */
47cbd05d 5769
5770static tree
1ebe9a83 5771fold_binary_op_with_conditional_arg (enum tree_code code,
5772 tree type, tree op0, tree op1,
5773 tree cond, tree arg, int cond_first_p)
47cbd05d 5774{
1ebe9a83 5775 tree cond_type = cond_first_p ? TREE_TYPE (op0) : TREE_TYPE (op1);
84b251e4 5776 tree arg_type = cond_first_p ? TREE_TYPE (op1) : TREE_TYPE (op0);
47cbd05d 5777 tree test, true_value, false_value;
5778 tree lhs = NULL_TREE;
5779 tree rhs = NULL_TREE;
a6661800 5780
f2b83d13 5781 /* This transformation is only worthwhile if we don't have to wrap
0975351b 5782 arg in a SAVE_EXPR, and the operation can be simplified on at least
f2b83d13 5783 one of the branches once its pushed inside the COND_EXPR. */
5784 if (!TREE_CONSTANT (arg))
a6661800 5785 return NULL_TREE;
5786
47cbd05d 5787 if (TREE_CODE (cond) == COND_EXPR)
5788 {
5789 test = TREE_OPERAND (cond, 0);
5790 true_value = TREE_OPERAND (cond, 1);
5791 false_value = TREE_OPERAND (cond, 2);
5792 /* If this operand throws an expression, then it does not make
5793 sense to try to perform a logical or arithmetic operation
f2b83d13 5794 involving it. */
47cbd05d 5795 if (VOID_TYPE_P (TREE_TYPE (true_value)))
f2b83d13 5796 lhs = true_value;
47cbd05d 5797 if (VOID_TYPE_P (TREE_TYPE (false_value)))
f2b83d13 5798 rhs = false_value;
47cbd05d 5799 }
5800 else
5801 {
5802 tree testtype = TREE_TYPE (cond);
5803 test = cond;
20783f07 5804 true_value = constant_boolean_node (true, testtype);
5805 false_value = constant_boolean_node (false, testtype);
47cbd05d 5806 }
d3371fcd 5807
5fe1fe72 5808 arg = fold_convert (arg_type, arg);
47cbd05d 5809 if (lhs == 0)
5fe1fe72 5810 {
5811 true_value = fold_convert (cond_type, true_value);
b085d4e5 5812 if (cond_first_p)
5813 lhs = fold_build2 (code, type, true_value, arg);
5814 else
5815 lhs = fold_build2 (code, type, arg, true_value);
5fe1fe72 5816 }
47cbd05d 5817 if (rhs == 0)
5fe1fe72 5818 {
5819 false_value = fold_convert (cond_type, false_value);
b085d4e5 5820 if (cond_first_p)
5821 rhs = fold_build2 (code, type, false_value, arg);
5822 else
5823 rhs = fold_build2 (code, type, arg, false_value);
5fe1fe72 5824 }
f2b83d13 5825
7ab7fd4f 5826 test = fold_build3 (COND_EXPR, type, test, lhs, rhs);
f2b83d13 5827 return fold_convert (type, test);
47cbd05d 5828}
5829
be2828ce 5830\f
920d0fb5 5831/* Subroutine of fold() that checks for the addition of +/- 0.0.
5832
5833 If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
5834 TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
5835 ADDEND is the same as X.
5836
6ef828f9 5837 X + 0 and X - 0 both give X when X is NaN, infinite, or nonzero
920d0fb5 5838 and finite. The problematic cases are when X is zero, and its mode
5839 has signed zeros. In the case of rounding towards -infinity,
5840 X - 0 is not the same as X because 0 - 0 is -0. In other rounding
5841 modes, X + 0 is not the same as X because -0 + 0 is 0. */
5842
5843static bool
de1b648b 5844fold_real_zero_addition_p (tree type, tree addend, int negate)
920d0fb5 5845{
5846 if (!real_zerop (addend))
5847 return false;
5848
c7590f7e 5849 /* Don't allow the fold with -fsignaling-nans. */
5850 if (HONOR_SNANS (TYPE_MODE (type)))
5851 return false;
5852
920d0fb5 5853 /* Allow the fold if zeros aren't signed, or their sign isn't important. */
5854 if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
5855 return true;
5856
5857 /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
5858 if (TREE_CODE (addend) == REAL_CST
5859 && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
5860 negate = !negate;
5861
5862 /* The mode has signed zeros, and we have to honor their sign.
5863 In this situation, there is only one case we can return true for.
5864 X - 0 is the same as X unless rounding towards -infinity is
5865 supported. */
5866 return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
5867}
5868
4b0b9adb 5869/* Subroutine of fold() that checks comparisons of built-in math
5870 functions against real constants.
5871
5872 FCODE is the DECL_FUNCTION_CODE of the built-in, CODE is the comparison
5873 operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR, GE_EXPR or LE_EXPR. TYPE
5874 is the type of the result and ARG0 and ARG1 are the operands of the
5875 comparison. ARG1 must be a TREE_REAL_CST.
5876
5877 The function returns the constant folded tree if a simplification
5878 can be made, and NULL_TREE otherwise. */
5879
5880static tree
dc81944a 5881fold_mathfn_compare (enum built_in_function fcode, enum tree_code code,
5882 tree type, tree arg0, tree arg1)
4b0b9adb 5883{
5884 REAL_VALUE_TYPE c;
5885
852da3c3 5886 if (BUILTIN_SQRT_P (fcode))
4b0b9adb 5887 {
5888 tree arg = TREE_VALUE (TREE_OPERAND (arg0, 1));
5889 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg0));
5890
5891 c = TREE_REAL_CST (arg1);
5892 if (REAL_VALUE_NEGATIVE (c))
5893 {
5894 /* sqrt(x) < y is always false, if y is negative. */
5895 if (code == EQ_EXPR || code == LT_EXPR || code == LE_EXPR)
20783f07 5896 return omit_one_operand (type, integer_zero_node, arg);
4b0b9adb 5897
5898 /* sqrt(x) > y is always true, if y is negative and we
5899 don't care about NaNs, i.e. negative values of x. */
5900 if (code == NE_EXPR || !HONOR_NANS (mode))
20783f07 5901 return omit_one_operand (type, integer_one_node, arg);
4b0b9adb 5902
5903 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
7ab7fd4f 5904 return fold_build2 (GE_EXPR, type, arg,
5905 build_real (TREE_TYPE (arg), dconst0));
4b0b9adb 5906 }
5907 else if (code == GT_EXPR || code == GE_EXPR)
5908 {
5909 REAL_VALUE_TYPE c2;
5910
5911 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5912 real_convert (&c2, mode, &c2);
5913
5914 if (REAL_VALUE_ISINF (c2))
5915 {
5916 /* sqrt(x) > y is x == +Inf, when y is very large. */
5917 if (HONOR_INFINITIES (mode))
7ab7fd4f 5918 return fold_build2 (EQ_EXPR, type, arg,
5919 build_real (TREE_TYPE (arg), c2));
4b0b9adb 5920
5921 /* sqrt(x) > y is always false, when y is very large
5922 and we don't care about infinities. */
20783f07 5923 return omit_one_operand (type, integer_zero_node, arg);
4b0b9adb 5924 }
5925
5926 /* sqrt(x) > c is the same as x > c*c. */
7ab7fd4f 5927 return fold_build2 (code, type, arg,
5928 build_real (TREE_TYPE (arg), c2));
4b0b9adb 5929 }
5930 else if (code == LT_EXPR || code == LE_EXPR)
5931 {
5932 REAL_VALUE_TYPE c2;
5933
5934 REAL_ARITHMETIC (c2, MULT_EXPR, c, c);
5935 real_convert (&c2, mode, &c2);
5936
5937 if (REAL_VALUE_ISINF (c2))
5938 {
5939 /* sqrt(x) < y is always true, when y is a very large
5940 value and we don't care about NaNs or Infinities. */
5941 if (! HONOR_NANS (mode) && ! HONOR_INFINITIES (mode))
20783f07 5942 return omit_one_operand (type, integer_one_node, arg);
4b0b9adb 5943
5944 /* sqrt(x) < y is x != +Inf when y is very large and we
5945 don't care about NaNs. */
5946 if (! HONOR_NANS (mode))
7ab7fd4f 5947 return fold_build2 (NE_EXPR, type, arg,
5948 build_real (TREE_TYPE (arg), c2));
4b0b9adb 5949
5950 /* sqrt(x) < y is x >= 0 when y is very large and we
5951 don't care about Infinities. */
5952 if (! HONOR_INFINITIES (mode))
7ab7fd4f 5953 return fold_build2 (GE_EXPR, type, arg,
5954 build_real (TREE_TYPE (arg), dconst0));
4b0b9adb 5955
5956 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
fa8b888f 5957 if (lang_hooks.decls.global_bindings_p () != 0
ce3fb06e 5958 || CONTAINS_PLACEHOLDER_P (arg))
4b0b9adb 5959 return NULL_TREE;
5960
5961 arg = save_expr (arg);
7ab7fd4f 5962 return fold_build2 (TRUTH_ANDIF_EXPR, type,
5963 fold_build2 (GE_EXPR, type, arg,
5964 build_real (TREE_TYPE (arg),
5965 dconst0)),
5966 fold_build2 (NE_EXPR, type, arg,
5967 build_real (TREE_TYPE (arg),
5968 c2)));
4b0b9adb 5969 }
5970
5971 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
5972 if (! HONOR_NANS (mode))
7ab7fd4f 5973 return fold_build2 (code, type, arg,
5974 build_real (TREE_TYPE (arg), c2));
4b0b9adb 5975
5976 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
fa8b888f 5977 if (lang_hooks.decls.global_bindings_p () == 0
ce3fb06e 5978 && ! CONTAINS_PLACEHOLDER_P (arg))
4b0b9adb 5979 {
5980 arg = save_expr (arg);
7ab7fd4f 5981 return fold_build2 (TRUTH_ANDIF_EXPR, type,
5982 fold_build2 (GE_EXPR, type, arg,
5983 build_real (TREE_TYPE (arg),
5984 dconst0)),
5985 fold_build2 (code, type, arg,
5986 build_real (TREE_TYPE (arg),
5987 c2)));
4b0b9adb 5988 }
5989 }
5990 }
5991
5992 return NULL_TREE;
5993}
5994
6d2e901f 5995/* Subroutine of fold() that optimizes comparisons against Infinities,
5996 either +Inf or -Inf.
5997
5998 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
5999 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6000 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6001
6002 The function returns the constant folded tree if a simplification
6003 can be made, and NULL_TREE otherwise. */
6004
6005static tree
de1b648b 6006fold_inf_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6d2e901f 6007{
ac4bd9a0 6008 enum machine_mode mode;
6009 REAL_VALUE_TYPE max;
6010 tree temp;
6011 bool neg;
6012
6013 mode = TYPE_MODE (TREE_TYPE (arg0));
6014
6d2e901f 6015 /* For negative infinity swap the sense of the comparison. */
ac4bd9a0 6016 neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1));
6017 if (neg)
6d2e901f 6018 code = swap_tree_comparison (code);
6019
6020 switch (code)
6021 {
6022 case GT_EXPR:
6023 /* x > +Inf is always false, if with ignore sNANs. */
ac4bd9a0 6024 if (HONOR_SNANS (mode))
6d2e901f 6025 return NULL_TREE;
20783f07 6026 return omit_one_operand (type, integer_zero_node, arg0);
6d2e901f 6027
6028 case LE_EXPR:
6029 /* x <= +Inf is always true, if we don't case about NaNs. */
ac4bd9a0 6030 if (! HONOR_NANS (mode))
20783f07 6031 return omit_one_operand (type, integer_one_node, arg0);
6d2e901f 6032
6033 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
fa8b888f 6034 if (lang_hooks.decls.global_bindings_p () == 0
ce3fb06e 6035 && ! CONTAINS_PLACEHOLDER_P (arg0))
6d2e901f 6036 {
6037 arg0 = save_expr (arg0);
7ab7fd4f 6038 return fold_build2 (EQ_EXPR, type, arg0, arg0);
6d2e901f 6039 }
6040 break;
6041
ac4bd9a0 6042 case EQ_EXPR:
6043 case GE_EXPR:
6044 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
6045 real_maxval (&max, neg, mode);
7ab7fd4f 6046 return fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6047 arg0, build_real (TREE_TYPE (arg0), max));
ac4bd9a0 6048
6049 case LT_EXPR:
6050 /* x < +Inf is always equal to x <= DBL_MAX. */
6051 real_maxval (&max, neg, mode);
7ab7fd4f 6052 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6053 arg0, build_real (TREE_TYPE (arg0), max));
ac4bd9a0 6054
6055 case NE_EXPR:
6056 /* x != +Inf is always equal to !(x > DBL_MAX). */
6057 real_maxval (&max, neg, mode);
6058 if (! HONOR_NANS (mode))
7ab7fd4f 6059 return fold_build2 (neg ? GE_EXPR : LE_EXPR, type,
6060 arg0, build_real (TREE_TYPE (arg0), max));
bd1ec513 6061
6062 /* The transformation below creates non-gimple code and thus is
6063 not appropriate if we are in gimple form. */
6064 if (in_gimple_form)
6065 return NULL_TREE;
7206da1b 6066
7ab7fd4f 6067 temp = fold_build2 (neg ? LT_EXPR : GT_EXPR, type,
6068 arg0, build_real (TREE_TYPE (arg0), max));
6069 return fold_build1 (TRUTH_NOT_EXPR, type, temp);
6d2e901f 6070
6071 default:
6072 break;
6073 }
6074
6075 return NULL_TREE;
6076}
920d0fb5 6077
270029e0 6078/* Subroutine of fold() that optimizes comparisons of a division by
365db11e 6079 a nonzero integer constant against an integer constant, i.e.
270029e0 6080 X/C1 op C2.
6081
6082 CODE is the comparison operator: EQ_EXPR, NE_EXPR, GT_EXPR, LT_EXPR,
6083 GE_EXPR or LE_EXPR. TYPE is the type of the result and ARG0 and ARG1
6084 are the operands of the comparison. ARG1 must be a TREE_REAL_CST.
6085
6086 The function returns the constant folded tree if a simplification
6087 can be made, and NULL_TREE otherwise. */
6088
6089static tree
6090fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1)
6091{
6092 tree prod, tmp, hi, lo;
6093 tree arg00 = TREE_OPERAND (arg0, 0);
6094 tree arg01 = TREE_OPERAND (arg0, 1);
6095 unsigned HOST_WIDE_INT lpart;
6096 HOST_WIDE_INT hpart;
81035ec1 6097 bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (arg0));
4e35b483 6098 bool neg_overflow;
270029e0 6099 int overflow;
6100
6101 /* We have to do this the hard way to detect unsigned overflow.
6102 prod = int_const_binop (MULT_EXPR, arg01, arg1, 0); */
81035ec1 6103 overflow = mul_double_with_sign (TREE_INT_CST_LOW (arg01),
6104 TREE_INT_CST_HIGH (arg01),
6105 TREE_INT_CST_LOW (arg1),
6106 TREE_INT_CST_HIGH (arg1),
6107 &lpart, &hpart, unsigned_p);
7016c612 6108 prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
4d28c5d1 6109 prod = force_fit_type (prod, -1, overflow, false);
4e35b483 6110 neg_overflow = false;
270029e0 6111
81035ec1 6112 if (unsigned_p)
270029e0 6113 {
6114 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
6115 lo = prod;
6116
6117 /* Likewise hi = int_const_binop (PLUS_EXPR, prod, tmp, 0). */
81035ec1 6118 overflow = add_double_with_sign (TREE_INT_CST_LOW (prod),
6119 TREE_INT_CST_HIGH (prod),
6120 TREE_INT_CST_LOW (tmp),
6121 TREE_INT_CST_HIGH (tmp),
6122 &lpart, &hpart, unsigned_p);
7016c612 6123 hi = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart);
4d28c5d1 6124 hi = force_fit_type (hi, -1, overflow | TREE_OVERFLOW (prod),
6125 TREE_CONSTANT_OVERFLOW (prod));
270029e0 6126 }
6127 else if (tree_int_cst_sgn (arg01) >= 0)
6128 {
6129 tmp = int_const_binop (MINUS_EXPR, arg01, integer_one_node, 0);
6130 switch (tree_int_cst_sgn (arg1))
6131 {
6132 case -1:
4e35b483 6133 neg_overflow = true;
270029e0 6134 lo = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6135 hi = prod;
6136 break;
6137
6138 case 0:
6139 lo = fold_negate_const (tmp, TREE_TYPE (arg0));
6140 hi = tmp;
6141 break;
6142
6143 case 1:
6144 hi = int_const_binop (PLUS_EXPR, prod, tmp, 0);
6145 lo = prod;
6146 break;
6147
6148 default:
fdada98f 6149 gcc_unreachable ();
270029e0 6150 }
6151 }
6152 else
6153 {
460c8e36 6154 /* A negative divisor reverses the relational operators. */
6155 code = swap_tree_comparison (code);
6156
270029e0 6157 tmp = int_const_binop (PLUS_EXPR, arg01, integer_one_node, 0);
6158 switch (tree_int_cst_sgn (arg1))
6159 {
6160 case -1:
6161 hi = int_const_binop (MINUS_EXPR, prod, tmp, 0);
6162 lo = prod;
6163 break;
6164
6165 case 0:
6166 hi = fold_negate_const (tmp, TREE_TYPE (arg0));
6167 lo = tmp;
6168 break;
6169
6170 case 1:
4e35b483 6171 neg_overflow = true;
6172 lo = int_const_binop (PLUS_EXPR, prod, tmp, 0);
270029e0 6173 hi = prod;
6174 break;
6175
6176 default:
fdada98f 6177 gcc_unreachable ();
270029e0 6178 }
6179 }
6180
6181 switch (code)
6182 {
6183 case EQ_EXPR:
6184 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6185 return omit_one_operand (type, integer_zero_node, arg00);
6186 if (TREE_OVERFLOW (hi))
7ab7fd4f 6187 return fold_build2 (GE_EXPR, type, arg00, lo);
270029e0 6188 if (TREE_OVERFLOW (lo))
7ab7fd4f 6189 return fold_build2 (LE_EXPR, type, arg00, hi);
270029e0 6190 return build_range_check (type, arg00, 1, lo, hi);
6191
6192 case NE_EXPR:
6193 if (TREE_OVERFLOW (lo) && TREE_OVERFLOW (hi))
6194 return omit_one_operand (type, integer_one_node, arg00);
6195 if (TREE_OVERFLOW (hi))
7ab7fd4f 6196 return fold_build2 (LT_EXPR, type, arg00, lo);
270029e0 6197 if (TREE_OVERFLOW (lo))
7ab7fd4f 6198 return fold_build2 (GT_EXPR, type, arg00, hi);
270029e0 6199 return build_range_check (type, arg00, 0, lo, hi);
6200
6201 case LT_EXPR:
6202 if (TREE_OVERFLOW (lo))
4e35b483 6203 {
6204 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6205 return omit_one_operand (type, tmp, arg00);
6206 }
7ab7fd4f 6207 return fold_build2 (LT_EXPR, type, arg00, lo);
270029e0 6208
6209 case LE_EXPR:
6210 if (TREE_OVERFLOW (hi))
4e35b483 6211 {
6212 tmp = neg_overflow ? integer_zero_node : integer_one_node;
6213 return omit_one_operand (type, tmp, arg00);
6214 }
7ab7fd4f 6215 return fold_build2 (LE_EXPR, type, arg00, hi);
270029e0 6216
6217 case GT_EXPR:
6218 if (TREE_OVERFLOW (hi))
4e35b483 6219 {
6220 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6221 return omit_one_operand (type, tmp, arg00);
6222 }
7ab7fd4f 6223 return fold_build2 (GT_EXPR, type, arg00, hi);
270029e0 6224
6225 case GE_EXPR:
6226 if (TREE_OVERFLOW (lo))
4e35b483 6227 {
6228 tmp = neg_overflow ? integer_one_node : integer_zero_node;
6229 return omit_one_operand (type, tmp, arg00);
6230 }
7ab7fd4f 6231 return fold_build2 (GE_EXPR, type, arg00, lo);
270029e0 6232
6233 default:
6234 break;
6235 }
6236
6237 return NULL_TREE;
6238}
6239
6240
6881f973 6241/* If CODE with arguments ARG0 and ARG1 represents a single bit
149f0db4 6242 equality/inequality test, then return a simplified form of the test
6243 using a sign testing. Otherwise return NULL. TYPE is the desired
6244 result type. */
7206da1b 6245
149f0db4 6246static tree
6247fold_single_bit_test_into_sign_test (enum tree_code code, tree arg0, tree arg1,
6248 tree result_type)
6881f973 6249{
6881f973 6250 /* If this is testing a single bit, we can optimize the test. */
6251 if ((code == NE_EXPR || code == EQ_EXPR)
6252 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6253 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6254 {
6881f973 6255 /* If we have (A & C) != 0 where C is the sign bit of A, convert
6256 this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
149f0db4 6257 tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0), TREE_OPERAND (arg0, 1));
6258
7cc00cbd 6259 if (arg00 != NULL_TREE
6260 /* This is only a win if casting to a signed type is cheap,
6261 i.e. when arg00's type is not a partial mode. */
6262 && TYPE_PRECISION (TREE_TYPE (arg00))
6263 == GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg00))))
6881f973 6264 {
fa8b888f 6265 tree stype = lang_hooks.types.signed_type (TREE_TYPE (arg00));
7ab7fd4f 6266 return fold_build2 (code == EQ_EXPR ? GE_EXPR : LT_EXPR,
6267 result_type, fold_convert (stype, arg00),
3c6185f1 6268 build_int_cst (stype, 0));
6881f973 6269 }
149f0db4 6270 }
6271
6272 return NULL_TREE;
6273}
6274
6275/* If CODE with arguments ARG0 and ARG1 represents a single bit
6276 equality/inequality test, then return a simplified form of
6277 the test using shifts and logical operations. Otherwise return
6278 NULL. TYPE is the desired result type. */
6279
6280tree
6281fold_single_bit_test (enum tree_code code, tree arg0, tree arg1,
6282 tree result_type)
6283{
6284 /* If this is testing a single bit, we can optimize the test. */
6285 if ((code == NE_EXPR || code == EQ_EXPR)
6286 && TREE_CODE (arg0) == BIT_AND_EXPR && integer_zerop (arg1)
6287 && integer_pow2p (TREE_OPERAND (arg0, 1)))
6288 {
6289 tree inner = TREE_OPERAND (arg0, 0);
6290 tree type = TREE_TYPE (arg0);
6291 int bitnum = tree_log2 (TREE_OPERAND (arg0, 1));
6292 enum machine_mode operand_mode = TYPE_MODE (type);
6293 int ops_unsigned;
6294 tree signed_type, unsigned_type, intermediate_type;
6295 tree tem;
6296
6297 /* First, see if we can fold the single bit test into a sign-bit
6298 test. */
6299 tem = fold_single_bit_test_into_sign_test (code, arg0, arg1,
6300 result_type);
6301 if (tem)
6302 return tem;
a4de5624 6303
7206da1b 6304 /* Otherwise we have (A & C) != 0 where C is a single bit,
6881f973 6305 convert that into ((A >> C2) & 1). Where C2 = log2(C).
6306 Similarly for (A & C) == 0. */
6307
6308 /* If INNER is a right shift of a constant and it plus BITNUM does
6309 not overflow, adjust BITNUM and INNER. */
6310 if (TREE_CODE (inner) == RSHIFT_EXPR
6311 && TREE_CODE (TREE_OPERAND (inner, 1)) == INTEGER_CST
6312 && TREE_INT_CST_HIGH (TREE_OPERAND (inner, 1)) == 0
6313 && bitnum < TYPE_PRECISION (type)
6314 && 0 > compare_tree_int (TREE_OPERAND (inner, 1),
6315 bitnum - TYPE_PRECISION (type)))
6316 {
6317 bitnum += TREE_INT_CST_LOW (TREE_OPERAND (inner, 1));
6318 inner = TREE_OPERAND (inner, 0);
6319 }
6320
6321 /* If we are going to be able to omit the AND below, we must do our
6322 operations as unsigned. If we must use the AND, we have a choice.
6323 Normally unsigned is faster, but for some machines signed is. */
6881f973 6324#ifdef LOAD_EXTEND_OP
a38d3d8b 6325 ops_unsigned = (LOAD_EXTEND_OP (operand_mode) == SIGN_EXTEND
6326 && !flag_syntax_only) ? 0 : 1;
6881f973 6327#else
a4de5624 6328 ops_unsigned = 1;
6881f973 6329#endif
6881f973 6330
fa8b888f 6331 signed_type = lang_hooks.types.type_for_mode (operand_mode, 0);
6332 unsigned_type = lang_hooks.types.type_for_mode (operand_mode, 1);
654d0fed 6333 intermediate_type = ops_unsigned ? unsigned_type : signed_type;
b30e3dbc 6334 inner = fold_convert (intermediate_type, inner);
6881f973 6335
6336 if (bitnum != 0)
fd96eeef 6337 inner = build2 (RSHIFT_EXPR, intermediate_type,
6338 inner, size_int (bitnum));
6881f973 6339
6340 if (code == EQ_EXPR)
7ab7fd4f 6341 inner = fold_build2 (BIT_XOR_EXPR, intermediate_type,
6342 inner, integer_one_node);
6881f973 6343
6344 /* Put the AND last so it can combine with more things. */
fd96eeef 6345 inner = build2 (BIT_AND_EXPR, intermediate_type,
6346 inner, integer_one_node);
6881f973 6347
6348 /* Make sure to return the proper type. */
b30e3dbc 6349 inner = fold_convert (result_type, inner);
6881f973 6350
6351 return inner;
6352 }
6353 return NULL_TREE;
6354}
fc3df357 6355
bd214d13 6356/* Check whether we are allowed to reorder operands arg0 and arg1,
6357 such that the evaluation of arg1 occurs before arg0. */
6358
6359static bool
6360reorder_operands_p (tree arg0, tree arg1)
6361{
6362 if (! flag_evaluation_order)
0c5713a2 6363 return true;
bd214d13 6364 if (TREE_CONSTANT (arg0) || TREE_CONSTANT (arg1))
6365 return true;
6366 return ! TREE_SIDE_EFFECTS (arg0)
6367 && ! TREE_SIDE_EFFECTS (arg1);
6368}
6369
88e11d8f 6370/* Test whether it is preferable two swap two operands, ARG0 and
6371 ARG1, for example because ARG0 is an integer constant and ARG1
bd214d13 6372 isn't. If REORDER is true, only recommend swapping if we can
6373 evaluate the operands in reverse order. */
88e11d8f 6374
cc0bdf91 6375bool
bd214d13 6376tree_swap_operands_p (tree arg0, tree arg1, bool reorder)
88e11d8f 6377{
6378 STRIP_SIGN_NOPS (arg0);
6379 STRIP_SIGN_NOPS (arg1);
6380
6381 if (TREE_CODE (arg1) == INTEGER_CST)
6382 return 0;
6383 if (TREE_CODE (arg0) == INTEGER_CST)
6384 return 1;
6385
6386 if (TREE_CODE (arg1) == REAL_CST)
6387 return 0;
6388 if (TREE_CODE (arg0) == REAL_CST)
6389 return 1;
6390
6391 if (TREE_CODE (arg1) == COMPLEX_CST)
6392 return 0;
6393 if (TREE_CODE (arg0) == COMPLEX_CST)
6394 return 1;
6395
6396 if (TREE_CONSTANT (arg1))
6397 return 0;
6398 if (TREE_CONSTANT (arg0))
6399 return 1;
7206da1b 6400
f9464d30 6401 if (optimize_size)
6402 return 0;
88e11d8f 6403
bd214d13 6404 if (reorder && flag_evaluation_order
6405 && (TREE_SIDE_EFFECTS (arg0) || TREE_SIDE_EFFECTS (arg1)))
6406 return 0;
6407
6408 if (DECL_P (arg1))
6409 return 0;
6410 if (DECL_P (arg0))
6411 return 1;
6412
cc0bdf91 6413 /* It is preferable to swap two SSA_NAME to ensure a canonical form
6414 for commutative and comparison operators. Ensuring a canonical
6415 form allows the optimizers to find additional redundancies without
6416 having to explicitly check for both orderings. */
6417 if (TREE_CODE (arg0) == SSA_NAME
6418 && TREE_CODE (arg1) == SSA_NAME
6419 && SSA_NAME_VERSION (arg0) > SSA_NAME_VERSION (arg1))
6420 return 1;
6421
88e11d8f 6422 return 0;
6423}
6424
faab57e3 6425/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where
6426 ARG0 is extended to a wider type. */
6427
6428static tree
6429fold_widened_comparison (enum tree_code code, tree type, tree arg0, tree arg1)
6430{
6431 tree arg0_unw = get_unwidened (arg0, NULL_TREE);
6432 tree arg1_unw;
6433 tree shorter_type, outer_type;
6434 tree min, max;
6435 bool above, below;
6436
6437 if (arg0_unw == arg0)
6438 return NULL_TREE;
6439 shorter_type = TREE_TYPE (arg0_unw);
fd66f095 6440
085bb6ea 6441#ifdef HAVE_canonicalize_funcptr_for_compare
6442 /* Disable this optimization if we're casting a function pointer
6443 type on targets that require function pointer canonicalization. */
6444 if (HAVE_canonicalize_funcptr_for_compare
6445 && TREE_CODE (shorter_type) == POINTER_TYPE
6446 && TREE_CODE (TREE_TYPE (shorter_type)) == FUNCTION_TYPE)
6447 return NULL_TREE;
6448#endif
6449
fd66f095 6450 if (TYPE_PRECISION (TREE_TYPE (arg0)) <= TYPE_PRECISION (shorter_type))
6451 return NULL_TREE;
6452
faab57e3 6453 arg1_unw = get_unwidened (arg1, shorter_type);
faab57e3 6454
6455 /* If possible, express the comparison in the shorter mode. */
6456 if ((code == EQ_EXPR || code == NE_EXPR
6457 || TYPE_UNSIGNED (TREE_TYPE (arg0)) == TYPE_UNSIGNED (shorter_type))
6458 && (TREE_TYPE (arg1_unw) == shorter_type
6459 || (TREE_CODE (arg1_unw) == INTEGER_CST
66787d4f 6460 && (TREE_CODE (shorter_type) == INTEGER_TYPE
6461 || TREE_CODE (shorter_type) == BOOLEAN_TYPE)
faab57e3 6462 && int_fits_type_p (arg1_unw, shorter_type))))
7ab7fd4f 6463 return fold_build2 (code, type, arg0_unw,
6464 fold_convert (shorter_type, arg1_unw));
faab57e3 6465
a5543a83 6466 if (TREE_CODE (arg1_unw) != INTEGER_CST
6467 || TREE_CODE (shorter_type) != INTEGER_TYPE
6468 || !int_fits_type_p (arg1_unw, shorter_type))
faab57e3 6469 return NULL_TREE;
6470
6471 /* If we are comparing with the integer that does not fit into the range
6472 of the shorter type, the result is known. */
6473 outer_type = TREE_TYPE (arg1_unw);
6474 min = lower_bound_in_type (outer_type, shorter_type);
6475 max = upper_bound_in_type (outer_type, shorter_type);
6476
6477 above = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6478 max, arg1_unw));
6479 below = integer_nonzerop (fold_relational_const (LT_EXPR, type,
6480 arg1_unw, min));
6481
6482 switch (code)
6483 {
6484 case EQ_EXPR:
6485 if (above || below)
20a8bb20 6486 return omit_one_operand (type, integer_zero_node, arg0);
faab57e3 6487 break;
6488
6489 case NE_EXPR:
6490 if (above || below)
20a8bb20 6491 return omit_one_operand (type, integer_one_node, arg0);
faab57e3 6492 break;
6493
6494 case LT_EXPR:
6495 case LE_EXPR:
6496 if (above)
20a8bb20 6497 return omit_one_operand (type, integer_one_node, arg0);
faab57e3 6498 else if (below)
20a8bb20 6499 return omit_one_operand (type, integer_zero_node, arg0);
faab57e3 6500
6501 case GT_EXPR:
6502 case GE_EXPR:
6503 if (above)
20a8bb20 6504 return omit_one_operand (type, integer_zero_node, arg0);
faab57e3 6505 else if (below)
20a8bb20 6506 return omit_one_operand (type, integer_one_node, arg0);
faab57e3 6507
6508 default:
6509 break;
6510 }
6511
6512 return NULL_TREE;
6513}
6514
6515/* Fold comparison ARG0 CODE ARG1 (with result in TYPE), where for
6516 ARG0 just the signedness is changed. */
6517
6518static tree
6519fold_sign_changed_comparison (enum tree_code code, tree type,
6520 tree arg0, tree arg1)
6521{
6522 tree arg0_inner, tmp;
6523 tree inner_type, outer_type;
6524
a846fd4d 6525 if (TREE_CODE (arg0) != NOP_EXPR
6526 && TREE_CODE (arg0) != CONVERT_EXPR)
faab57e3 6527 return NULL_TREE;
6528
6529 outer_type = TREE_TYPE (arg0);
6530 arg0_inner = TREE_OPERAND (arg0, 0);
6531 inner_type = TREE_TYPE (arg0_inner);
6532
085bb6ea 6533#ifdef HAVE_canonicalize_funcptr_for_compare
6534 /* Disable this optimization if we're casting a function pointer
6535 type on targets that require function pointer canonicalization. */
6536 if (HAVE_canonicalize_funcptr_for_compare
6537 && TREE_CODE (inner_type) == POINTER_TYPE
6538 && TREE_CODE (TREE_TYPE (inner_type)) == FUNCTION_TYPE)
6539 return NULL_TREE;
6540#endif
6541
faab57e3 6542 if (TYPE_PRECISION (inner_type) != TYPE_PRECISION (outer_type))
6543 return NULL_TREE;
6544
6545 if (TREE_CODE (arg1) != INTEGER_CST
a846fd4d 6546 && !((TREE_CODE (arg1) == NOP_EXPR
6547 || TREE_CODE (arg1) == CONVERT_EXPR)
faab57e3 6548 && TREE_TYPE (TREE_OPERAND (arg1, 0)) == inner_type))
6549 return NULL_TREE;
6550
6551 if (TYPE_UNSIGNED (inner_type) != TYPE_UNSIGNED (outer_type)
6552 && code != NE_EXPR
6553 && code != EQ_EXPR)
6554 return NULL_TREE;
6555
6556 if (TREE_CODE (arg1) == INTEGER_CST)
6557 {
6558 tmp = build_int_cst_wide (inner_type,
6559 TREE_INT_CST_LOW (arg1),
6560 TREE_INT_CST_HIGH (arg1));
6561 arg1 = force_fit_type (tmp, 0,
6562 TREE_OVERFLOW (arg1),
6563 TREE_CONSTANT_OVERFLOW (arg1));
6564 }
6565 else
6566 arg1 = fold_convert (inner_type, arg1);
6567
7ab7fd4f 6568 return fold_build2 (code, type, arg0_inner, arg1);
faab57e3 6569}
6570
dede8dcc 6571/* Tries to replace &a[idx] CODE s * delta with &a[idx CODE delta], if s is
ad1f9c12 6572 step of the array. Reconstructs s and delta in the case of s * delta
6573 being an integer constant (and thus already folded).
6574 ADDR is the address. MULT is the multiplicative expression.
e709f9ea 6575 If the function succeeds, the new address expression is returned. Otherwise
6576 NULL_TREE is returned. */
dede8dcc 6577
6578static tree
ad1f9c12 6579try_move_mult_to_index (enum tree_code code, tree addr, tree op1)
dede8dcc 6580{
6581 tree s, delta, step;
dede8dcc 6582 tree ref = TREE_OPERAND (addr, 0), pref;
6583 tree ret, pos;
6584 tree itype;
6585
ad1f9c12 6586 /* Canonicalize op1 into a possibly non-constant delta
6587 and an INTEGER_CST s. */
6588 if (TREE_CODE (op1) == MULT_EXPR)
dede8dcc 6589 {
ad1f9c12 6590 tree arg0 = TREE_OPERAND (op1, 0), arg1 = TREE_OPERAND (op1, 1);
6591
6592 STRIP_NOPS (arg0);
6593 STRIP_NOPS (arg1);
6594
6595 if (TREE_CODE (arg0) == INTEGER_CST)
6596 {
6597 s = arg0;
6598 delta = arg1;
6599 }
6600 else if (TREE_CODE (arg1) == INTEGER_CST)
6601 {
6602 s = arg1;
6603 delta = arg0;
6604 }
6605 else
6606 return NULL_TREE;
dede8dcc 6607 }
ad1f9c12 6608 else if (TREE_CODE (op1) == INTEGER_CST)
dede8dcc 6609 {
ad1f9c12 6610 delta = op1;
6611 s = NULL_TREE;
dede8dcc 6612 }
6613 else
ad1f9c12 6614 {
6615 /* Simulate we are delta * 1. */
6616 delta = op1;
6617 s = integer_one_node;
6618 }
dede8dcc 6619
6620 for (;; ref = TREE_OPERAND (ref, 0))
6621 {
6622 if (TREE_CODE (ref) == ARRAY_REF)
6623 {
86f023fe 6624 itype = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (ref, 0)));
6625 if (! itype)
6626 continue;
6627
dede8dcc 6628 step = array_ref_element_size (ref);
dede8dcc 6629 if (TREE_CODE (step) != INTEGER_CST)
6630 continue;
6631
ad1f9c12 6632 if (s)
6633 {
6634 if (! tree_int_cst_equal (step, s))
6635 continue;
6636 }
6637 else
6638 {
6639 /* Try if delta is a multiple of step. */
86f023fe 6640 tree tmp = div_if_zero_remainder (EXACT_DIV_EXPR, delta, step);
6641 if (! tmp)
ad1f9c12 6642 continue;
86f023fe 6643 delta = tmp;
ad1f9c12 6644 }
dede8dcc 6645
dede8dcc 6646 break;
6647 }
6648
6649 if (!handled_component_p (ref))
6650 return NULL_TREE;
6651 }
6652
6653 /* We found the suitable array reference. So copy everything up to it,
6654 and replace the index. */
6655
6656 pref = TREE_OPERAND (addr, 0);
6657 ret = copy_node (pref);
6658 pos = ret;
6659
6660 while (pref != ref)
6661 {
6662 pref = TREE_OPERAND (pref, 0);
6663 TREE_OPERAND (pos, 0) = copy_node (pref);
6664 pos = TREE_OPERAND (pos, 0);
6665 }
6666
7ab7fd4f 6667 TREE_OPERAND (pos, 1) = fold_build2 (code, itype,
ad1f9c12 6668 fold_convert (itype,
6669 TREE_OPERAND (pos, 1)),
6670 fold_convert (itype, delta));
dede8dcc 6671
e7be49a3 6672 return fold_build1 (ADDR_EXPR, TREE_TYPE (addr), ret);
dede8dcc 6673}
6674
9a73db25 6675
6676/* Fold A < X && A + 1 > Y to A < X && A >= Y. Normally A + 1 > Y
6677 means A >= Y && A != MAX, but in this case we know that
6678 A < X <= MAX. INEQ is A + 1 > Y, BOUND is A < X. */
6679
6680static tree
6681fold_to_nonsharp_ineq_using_bound (tree ineq, tree bound)
6682{
6683 tree a, typea, type = TREE_TYPE (ineq), a1, diff, y;
6684
6685 if (TREE_CODE (bound) == LT_EXPR)
6686 a = TREE_OPERAND (bound, 0);
6687 else if (TREE_CODE (bound) == GT_EXPR)
6688 a = TREE_OPERAND (bound, 1);
6689 else
6690 return NULL_TREE;
6691
6692 typea = TREE_TYPE (a);
6693 if (!INTEGRAL_TYPE_P (typea)
6694 && !POINTER_TYPE_P (typea))
6695 return NULL_TREE;
6696
6697 if (TREE_CODE (ineq) == LT_EXPR)
6698 {
6699 a1 = TREE_OPERAND (ineq, 1);
6700 y = TREE_OPERAND (ineq, 0);
6701 }
6702 else if (TREE_CODE (ineq) == GT_EXPR)
6703 {
6704 a1 = TREE_OPERAND (ineq, 0);
6705 y = TREE_OPERAND (ineq, 1);
6706 }
6707 else
6708 return NULL_TREE;
6709
6710 if (TREE_TYPE (a1) != typea)
6711 return NULL_TREE;
6712
7ab7fd4f 6713 diff = fold_build2 (MINUS_EXPR, typea, a1, a);
9a73db25 6714 if (!integer_onep (diff))
6715 return NULL_TREE;
6716
7ab7fd4f 6717 return fold_build2 (GE_EXPR, type, a, y);
9a73db25 6718}
6719
1c9af531 6720/* Fold a sum or difference of at least one multiplication.
6721 Returns the folded tree or NULL if no simplification could be made. */
6722
6723static tree
6724fold_plusminus_mult_expr (enum tree_code code, tree type, tree arg0, tree arg1)
6725{
6726 tree arg00, arg01, arg10, arg11;
6727 tree alt0 = NULL_TREE, alt1 = NULL_TREE, same;
6728
6729 /* (A * C) +- (B * C) -> (A+-B) * C.
6730 (A * C) +- A -> A * (C+-1).
6731 We are most concerned about the case where C is a constant,
6732 but other combinations show up during loop reduction. Since
6733 it is not difficult, try all four possibilities. */
6734
6735 if (TREE_CODE (arg0) == MULT_EXPR)
6736 {
6737 arg00 = TREE_OPERAND (arg0, 0);
6738 arg01 = TREE_OPERAND (arg0, 1);
6739 }
6740 else
6741 {
6742 arg00 = arg0;
ba56cb50 6743 arg01 = build_one_cst (type);
1c9af531 6744 }
6745 if (TREE_CODE (arg1) == MULT_EXPR)
6746 {
6747 arg10 = TREE_OPERAND (arg1, 0);
6748 arg11 = TREE_OPERAND (arg1, 1);
6749 }
6750 else
6751 {
6752 arg10 = arg1;
ba56cb50 6753 arg11 = build_one_cst (type);
1c9af531 6754 }
6755 same = NULL_TREE;
6756
6757 if (operand_equal_p (arg01, arg11, 0))
6758 same = arg01, alt0 = arg00, alt1 = arg10;
6759 else if (operand_equal_p (arg00, arg10, 0))
6760 same = arg00, alt0 = arg01, alt1 = arg11;
6761 else if (operand_equal_p (arg00, arg11, 0))
6762 same = arg00, alt0 = arg01, alt1 = arg10;
6763 else if (operand_equal_p (arg01, arg10, 0))
6764 same = arg01, alt0 = arg00, alt1 = arg11;
6765
6766 /* No identical multiplicands; see if we can find a common
6767 power-of-two factor in non-power-of-two multiplies. This
6768 can help in multi-dimensional array access. */
6769 else if (host_integerp (arg01, 0)
6770 && host_integerp (arg11, 0))
6771 {
6772 HOST_WIDE_INT int01, int11, tmp;
6773 bool swap = false;
6774 tree maybe_same;
6775 int01 = TREE_INT_CST_LOW (arg01);
6776 int11 = TREE_INT_CST_LOW (arg11);
6777
6778 /* Move min of absolute values to int11. */
6779 if ((int01 >= 0 ? int01 : -int01)
6780 < (int11 >= 0 ? int11 : -int11))
6781 {
6782 tmp = int01, int01 = int11, int11 = tmp;
6783 alt0 = arg00, arg00 = arg10, arg10 = alt0;
6784 maybe_same = arg01;
6785 swap = true;
6786 }
6787 else
6788 maybe_same = arg11;
6789
8a7907c1 6790 if (exact_log2 (abs (int11)) > 0 && int01 % int11 == 0)
1c9af531 6791 {
6792 alt0 = fold_build2 (MULT_EXPR, TREE_TYPE (arg00), arg00,
6793 build_int_cst (TREE_TYPE (arg00),
6794 int01 / int11));
6795 alt1 = arg10;
6796 same = maybe_same;
6797 if (swap)
6798 maybe_same = alt0, alt0 = alt1, alt1 = maybe_same;
6799 }
6800 }
6801
6802 if (same)
6803 return fold_build2 (MULT_EXPR, type,
6804 fold_build2 (code, type,
6805 fold_convert (type, alt0),
6806 fold_convert (type, alt1)),
6807 fold_convert (type, same));
6808
6809 return NULL_TREE;
6810}
6811
5f4092ed 6812/* Subroutine of native_encode_expr. Encode the INTEGER_CST
6813 specified by EXPR into the buffer PTR of length LEN bytes.
6814 Return the number of bytes placed in the buffer, or zero
6815 upon failure. */
6816
6817static int
6818native_encode_int (tree expr, unsigned char *ptr, int len)
6819{
6820 tree type = TREE_TYPE (expr);
6821 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
6822 int byte, offset, word, words;
6823 unsigned char value;
6824
6825 if (total_bytes > len)
6826 return 0;
6827 words = total_bytes / UNITS_PER_WORD;
6828
6829 for (byte = 0; byte < total_bytes; byte++)
6830 {
6831 int bitpos = byte * BITS_PER_UNIT;
6832 if (bitpos < HOST_BITS_PER_WIDE_INT)
6833 value = (unsigned char) (TREE_INT_CST_LOW (expr) >> bitpos);
6834 else
6835 value = (unsigned char) (TREE_INT_CST_HIGH (expr)
6836 >> (bitpos - HOST_BITS_PER_WIDE_INT));
6837
6838 if (total_bytes > UNITS_PER_WORD)
6839 {
6840 word = byte / UNITS_PER_WORD;
6841 if (WORDS_BIG_ENDIAN)
6842 word = (words - 1) - word;
6843 offset = word * UNITS_PER_WORD;
6844 if (BYTES_BIG_ENDIAN)
6845 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
6846 else
6847 offset += byte % UNITS_PER_WORD;
6848 }
6849 else
6850 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
6851 ptr[offset] = value;
6852 }
6853 return total_bytes;
6854}
6855
6856
6857/* Subroutine of native_encode_expr. Encode the REAL_CST
6858 specified by EXPR into the buffer PTR of length LEN bytes.
6859 Return the number of bytes placed in the buffer, or zero
6860 upon failure. */
6861
6862static int
6863native_encode_real (tree expr, unsigned char *ptr, int len)
6864{
6865 tree type = TREE_TYPE (expr);
6866 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
6867 int byte, offset, word, words;
6868 unsigned char value;
6869
6870 /* There are always 32 bits in each long, no matter the size of
6871 the hosts long. We handle floating point representations with
6872 up to 192 bits. */
6873 long tmp[6];
6874
6875 if (total_bytes > len)
6876 return 0;
6877 words = total_bytes / UNITS_PER_WORD;
6878
6879 real_to_target (tmp, TREE_REAL_CST_PTR (expr), TYPE_MODE (type));
6880
6881 for (byte = 0; byte < total_bytes; byte++)
6882 {
6883 int bitpos = byte * BITS_PER_UNIT;
6884 value = (unsigned char) (tmp[bitpos / 32] >> (bitpos & 31));
6885
6886 if (total_bytes > UNITS_PER_WORD)
6887 {
6888 word = byte / UNITS_PER_WORD;
6889 if (FLOAT_WORDS_BIG_ENDIAN)
6890 word = (words - 1) - word;
6891 offset = word * UNITS_PER_WORD;
6892 if (BYTES_BIG_ENDIAN)
6893 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
6894 else
6895 offset += byte % UNITS_PER_WORD;
6896 }
6897 else
6898 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
6899 ptr[offset] = value;
6900 }
6901 return total_bytes;
6902}
6903
6904/* Subroutine of native_encode_expr. Encode the COMPLEX_CST
6905 specified by EXPR into the buffer PTR of length LEN bytes.
6906 Return the number of bytes placed in the buffer, or zero
6907 upon failure. */
6908
6909static int
6910native_encode_complex (tree expr, unsigned char *ptr, int len)
6911{
6912 int rsize, isize;
6913 tree part;
6914
6915 part = TREE_REALPART (expr);
6916 rsize = native_encode_expr (part, ptr, len);
6917 if (rsize == 0)
6918 return 0;
6919 part = TREE_IMAGPART (expr);
6920 isize = native_encode_expr (part, ptr+rsize, len-rsize);
6921 if (isize != rsize)
6922 return 0;
6923 return rsize + isize;
6924}
6925
6926
6927/* Subroutine of native_encode_expr. Encode the VECTOR_CST
6928 specified by EXPR into the buffer PTR of length LEN bytes.
6929 Return the number of bytes placed in the buffer, or zero
6930 upon failure. */
6931
6932static int
6933native_encode_vector (tree expr, unsigned char *ptr, int len)
6934{
3fa15ed1 6935 int i, size, offset, count;
9fd22806 6936 tree itype, elem, elements;
5f4092ed 6937
5f4092ed 6938 offset = 0;
6939 elements = TREE_VECTOR_CST_ELTS (expr);
6940 count = TYPE_VECTOR_SUBPARTS (TREE_TYPE (expr));
9fd22806 6941 itype = TREE_TYPE (TREE_TYPE (expr));
6942 size = GET_MODE_SIZE (TYPE_MODE (itype));
5f4092ed 6943 for (i = 0; i < count; i++)
6944 {
6945 if (elements)
6946 {
6947 elem = TREE_VALUE (elements);
6948 elements = TREE_CHAIN (elements);
6949 }
6950 else
6951 elem = NULL_TREE;
6952
6953 if (elem)
6954 {
9fd22806 6955 if (native_encode_expr (elem, ptr+offset, len-offset) != size)
5f4092ed 6956 return 0;
6957 }
9fd22806 6958 else
5f4092ed 6959 {
6960 if (offset + size > len)
6961 return 0;
6962 memset (ptr+offset, 0, size);
6963 }
5f4092ed 6964 offset += size;
6965 }
6966 return offset;
6967}
6968
6969
6970/* Subroutine of fold_view_convert_expr. Encode the INTEGER_CST,
6971 REAL_CST, COMPLEX_CST or VECTOR_CST specified by EXPR into the
6972 buffer PTR of length LEN bytes. Return the number of bytes
6973 placed in the buffer, or zero upon failure. */
6974
6975static int
6976native_encode_expr (tree expr, unsigned char *ptr, int len)
6977{
6978 switch (TREE_CODE (expr))
6979 {
6980 case INTEGER_CST:
6981 return native_encode_int (expr, ptr, len);
6982
6983 case REAL_CST:
6984 return native_encode_real (expr, ptr, len);
6985
6986 case COMPLEX_CST:
6987 return native_encode_complex (expr, ptr, len);
6988
6989 case VECTOR_CST:
6990 return native_encode_vector (expr, ptr, len);
6991
6992 default:
6993 return 0;
6994 }
6995}
6996
6997
6998/* Subroutine of native_interpret_expr. Interpret the contents of
6999 the buffer PTR of length LEN as an INTEGER_CST of type TYPE.
7000 If the buffer cannot be interpreted, return NULL_TREE. */
7001
7002static tree
7003native_interpret_int (tree type, unsigned char *ptr, int len)
7004{
7005 int total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7006 int byte, offset, word, words;
7007 unsigned char value;
7008 unsigned int HOST_WIDE_INT lo = 0;
7009 HOST_WIDE_INT hi = 0;
7010
7011 if (total_bytes > len)
7012 return NULL_TREE;
7013 if (total_bytes * BITS_PER_UNIT > 2 * HOST_BITS_PER_WIDE_INT)
7014 return NULL_TREE;
7015 words = total_bytes / UNITS_PER_WORD;
7016
7017 for (byte = 0; byte < total_bytes; byte++)
7018 {
7019 int bitpos = byte * BITS_PER_UNIT;
7020 if (total_bytes > UNITS_PER_WORD)
7021 {
7022 word = byte / UNITS_PER_WORD;
7023 if (WORDS_BIG_ENDIAN)
7024 word = (words - 1) - word;
7025 offset = word * UNITS_PER_WORD;
7026 if (BYTES_BIG_ENDIAN)
7027 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7028 else
7029 offset += byte % UNITS_PER_WORD;
7030 }
7031 else
7032 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7033 value = ptr[offset];
7034
7035 if (bitpos < HOST_BITS_PER_WIDE_INT)
7036 lo |= (unsigned HOST_WIDE_INT) value << bitpos;
7037 else
7038 hi |= (unsigned HOST_WIDE_INT) value
7039 << (bitpos - HOST_BITS_PER_WIDE_INT);
7040 }
7041
7042 return force_fit_type (build_int_cst_wide (type, lo, hi),
7043 0, false, false);
7044}
7045
7046
7047/* Subroutine of native_interpret_expr. Interpret the contents of
7048 the buffer PTR of length LEN as a REAL_CST of type TYPE.
7049 If the buffer cannot be interpreted, return NULL_TREE. */
7050
7051static tree
7052native_interpret_real (tree type, unsigned char *ptr, int len)
7053{
3fa15ed1 7054 enum machine_mode mode = TYPE_MODE (type);
7055 int total_bytes = GET_MODE_SIZE (mode);
5f4092ed 7056 int byte, offset, word, words;
7057 unsigned char value;
7058 /* There are always 32 bits in each long, no matter the size of
7059 the hosts long. We handle floating point representations with
7060 up to 192 bits. */
7061 REAL_VALUE_TYPE r;
7062 long tmp[6];
7063
7064 total_bytes = GET_MODE_SIZE (TYPE_MODE (type));
7065 if (total_bytes > len || total_bytes > 24)
7066 return NULL_TREE;
7067 words = total_bytes / UNITS_PER_WORD;
7068
7069 memset (tmp, 0, sizeof (tmp));
7070 for (byte = 0; byte < total_bytes; byte++)
7071 {
7072 int bitpos = byte * BITS_PER_UNIT;
7073 if (total_bytes > UNITS_PER_WORD)
7074 {
7075 word = byte / UNITS_PER_WORD;
7076 if (FLOAT_WORDS_BIG_ENDIAN)
7077 word = (words - 1) - word;
7078 offset = word * UNITS_PER_WORD;
7079 if (BYTES_BIG_ENDIAN)
7080 offset += (UNITS_PER_WORD - 1) - (byte % UNITS_PER_WORD);
7081 else
7082 offset += byte % UNITS_PER_WORD;
7083 }
7084 else
7085 offset = BYTES_BIG_ENDIAN ? (total_bytes - 1) - byte : byte;
7086 value = ptr[offset];
7087
7088 tmp[bitpos / 32] |= (unsigned long)value << (bitpos & 31);
7089 }
7090
7091 real_from_target (&r, tmp, mode);
7092 return build_real (type, r);
7093}
7094
7095
7096/* Subroutine of native_interpret_expr. Interpret the contents of
7097 the buffer PTR of length LEN as a COMPLEX_CST of type TYPE.
7098 If the buffer cannot be interpreted, return NULL_TREE. */
7099
7100static tree
7101native_interpret_complex (tree type, unsigned char *ptr, int len)
7102{
7103 tree etype, rpart, ipart;
7104 int size;
7105
7106 etype = TREE_TYPE (type);
7107 size = GET_MODE_SIZE (TYPE_MODE (etype));
7108 if (size * 2 > len)
7109 return NULL_TREE;
7110 rpart = native_interpret_expr (etype, ptr, size);
7111 if (!rpart)
7112 return NULL_TREE;
7113 ipart = native_interpret_expr (etype, ptr+size, size);
7114 if (!ipart)
7115 return NULL_TREE;
7116 return build_complex (type, rpart, ipart);
7117}
7118
7119
7120/* Subroutine of native_interpret_expr. Interpret the contents of
7121 the buffer PTR of length LEN as a VECTOR_CST of type TYPE.
7122 If the buffer cannot be interpreted, return NULL_TREE. */
7123
7124static tree
7125native_interpret_vector (tree type, unsigned char *ptr, int len)
7126{
7127 tree etype, elem, elements;
7128 int i, size, count;
7129
7130 etype = TREE_TYPE (type);
7131 size = GET_MODE_SIZE (TYPE_MODE (etype));
7132 count = TYPE_VECTOR_SUBPARTS (type);
7133 if (size * count > len)
7134 return NULL_TREE;
7135
7136 elements = NULL_TREE;
7137 for (i = count - 1; i >= 0; i--)
7138 {
7139 elem = native_interpret_expr (etype, ptr+(i*size), size);
7140 if (!elem)
7141 return NULL_TREE;
7142 elements = tree_cons (NULL_TREE, elem, elements);
7143 }
7144 return build_vector (type, elements);
7145}
7146
7147
d961ae3a 7148/* Subroutine of fold_view_convert_expr. Interpret the contents of
5f4092ed 7149 the buffer PTR of length LEN as a constant of type TYPE. For
7150 INTEGRAL_TYPE_P we return an INTEGER_CST, for SCALAR_FLOAT_TYPE_P
7151 we return a REAL_CST, etc... If the buffer cannot be interpreted,
7152 return NULL_TREE. */
7153
7154static tree
7155native_interpret_expr (tree type, unsigned char *ptr, int len)
7156{
7157 switch (TREE_CODE (type))
7158 {
7159 case INTEGER_TYPE:
7160 case ENUMERAL_TYPE:
7161 case BOOLEAN_TYPE:
7162 return native_interpret_int (type, ptr, len);
7163
7164 case REAL_TYPE:
7165 return native_interpret_real (type, ptr, len);
7166
7167 case COMPLEX_TYPE:
7168 return native_interpret_complex (type, ptr, len);
7169
7170 case VECTOR_TYPE:
7171 return native_interpret_vector (type, ptr, len);
7172
7173 default:
7174 return NULL_TREE;
7175 }
7176}
7177
7178
7179/* Fold a VIEW_CONVERT_EXPR of a constant expression EXPR to type
7180 TYPE at compile-time. If we're unable to perform the conversion
7181 return NULL_TREE. */
7182
7183static tree
7184fold_view_convert_expr (tree type, tree expr)
7185{
7186 /* We support up to 512-bit values (for V8DFmode). */
7187 unsigned char buffer[64];
7188 int len;
7189
7190 /* Check that the host and target are sane. */
7191 if (CHAR_BIT != 8 || BITS_PER_UNIT != 8)
7192 return NULL_TREE;
7193
7194 len = native_encode_expr (expr, buffer, sizeof (buffer));
7195 if (len == 0)
7196 return NULL_TREE;
7197
7198 return native_interpret_expr (type, buffer, len);
7199}
7200
7201
0d3711e2 7202/* Fold a unary expression of code CODE and type TYPE with operand
7203 OP0. Return the folded expression if folding is successful.
7204 Otherwise, return NULL_TREE. */
422c18cb 7205
d3858e14 7206tree
0052b98e 7207fold_unary (enum tree_code code, tree type, tree op0)
422c18cb 7208{
422c18cb 7209 tree tem;
0052b98e 7210 tree arg0;
422c18cb 7211 enum tree_code_class kind = TREE_CODE_CLASS (code);
7212
7213 gcc_assert (IS_EXPR_CODE_CLASS (kind)
7214 && TREE_CODE_LENGTH (code) == 1);
7215
0052b98e 7216 arg0 = op0;
422c18cb 7217 if (arg0)
7218 {
00bb4a78 7219 if (code == NOP_EXPR || code == CONVERT_EXPR
7220 || code == FLOAT_EXPR || code == ABS_EXPR)
422c18cb 7221 {
00bb4a78 7222 /* Don't use STRIP_NOPS, because signedness of argument type
7223 matters. */
422c18cb 7224 STRIP_SIGN_NOPS (arg0);
7225 }
7226 else
7227 {
7228 /* Strip any conversions that don't change the mode. This
7229 is safe for every expression, except for a comparison
7230 expression because its signedness is derived from its
7231 operands.
7232
7233 Note that this is done as an internal manipulation within
7234 the constant folder, in order to find the simplest
7235 representation of the arguments so that their form can be
7236 studied. In any cases, the appropriate type conversions
7237 should be put back in the tree that will get out of the
7238 constant folder. */
7239 STRIP_NOPS (arg0);
7240 }
7241 }
7242
7243 if (TREE_CODE_CLASS (code) == tcc_unary)
7244 {
7245 if (TREE_CODE (arg0) == COMPOUND_EXPR)
7246 return build2 (COMPOUND_EXPR, type, TREE_OPERAND (arg0, 0),
7ab7fd4f 7247 fold_build1 (code, type, TREE_OPERAND (arg0, 1)));
422c18cb 7248 else if (TREE_CODE (arg0) == COND_EXPR)
7249 {
7250 tree arg01 = TREE_OPERAND (arg0, 1);
7251 tree arg02 = TREE_OPERAND (arg0, 2);
7252 if (! VOID_TYPE_P (TREE_TYPE (arg01)))
7ab7fd4f 7253 arg01 = fold_build1 (code, type, arg01);
422c18cb 7254 if (! VOID_TYPE_P (TREE_TYPE (arg02)))
7ab7fd4f 7255 arg02 = fold_build1 (code, type, arg02);
7256 tem = fold_build3 (COND_EXPR, type, TREE_OPERAND (arg0, 0),
7257 arg01, arg02);
422c18cb 7258
7259 /* If this was a conversion, and all we did was to move into
7260 inside the COND_EXPR, bring it back out. But leave it if
7261 it is a conversion from integer to integer and the
7262 result precision is no wider than a word since such a
7263 conversion is cheap and may be optimized away by combine,
7264 while it couldn't if it were outside the COND_EXPR. Then return
7265 so we don't get into an infinite recursion loop taking the
7266 conversion out and then back in. */
7267
7268 if ((code == NOP_EXPR || code == CONVERT_EXPR
7269 || code == NON_LVALUE_EXPR)
7270 && TREE_CODE (tem) == COND_EXPR
7271 && TREE_CODE (TREE_OPERAND (tem, 1)) == code
7272 && TREE_CODE (TREE_OPERAND (tem, 2)) == code
7273 && ! VOID_TYPE_P (TREE_OPERAND (tem, 1))
7274 && ! VOID_TYPE_P (TREE_OPERAND (tem, 2))
7275 && (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))
7276 == TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 2), 0)))
7277 && (! (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7278 && (INTEGRAL_TYPE_P
7279 (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (tem, 1), 0))))
7280 && TYPE_PRECISION (TREE_TYPE (tem)) <= BITS_PER_WORD)
7281 || flag_syntax_only))
7282 tem = build1 (code, type,
7283 build3 (COND_EXPR,
7284 TREE_TYPE (TREE_OPERAND
7285 (TREE_OPERAND (tem, 1), 0)),
7286 TREE_OPERAND (tem, 0),
7287 TREE_OPERAND (TREE_OPERAND (tem, 1), 0),
7288 TREE_OPERAND (TREE_OPERAND (tem, 2), 0)));
7289 return tem;
7290 }
7291 else if (COMPARISON_CLASS_P (arg0))
7292 {
7293 if (TREE_CODE (type) == BOOLEAN_TYPE)
7294 {
7295 arg0 = copy_node (arg0);
7296 TREE_TYPE (arg0) = type;
7297 return arg0;
7298 }
7299 else if (TREE_CODE (type) != INTEGER_TYPE)
7ab7fd4f 7300 return fold_build3 (COND_EXPR, type, arg0,
7301 fold_build1 (code, type,
7302 integer_one_node),
7303 fold_build1 (code, type,
7304 integer_zero_node));
422c18cb 7305 }
7306 }
7307
7308 switch (code)
7309 {
7310 case NOP_EXPR:
7311 case FLOAT_EXPR:
7312 case CONVERT_EXPR:
7313 case FIX_TRUNC_EXPR:
7314 case FIX_CEIL_EXPR:
7315 case FIX_FLOOR_EXPR:
7316 case FIX_ROUND_EXPR:
fac5aff3 7317 if (TREE_TYPE (op0) == type)
7318 return op0;
8aa776be 7319
191ec5a2 7320 /* If we have (type) (a CMP b) and type is an integral type, return
8aa776be 7321 new expression involving the new type. */
7322 if (COMPARISON_CLASS_P (op0) && INTEGRAL_TYPE_P (type))
7323 return fold_build2 (TREE_CODE (op0), type, TREE_OPERAND (op0, 0),
7324 TREE_OPERAND (op0, 1));
422c18cb 7325
7326 /* Handle cases of two conversions in a row. */
fac5aff3 7327 if (TREE_CODE (op0) == NOP_EXPR
7328 || TREE_CODE (op0) == CONVERT_EXPR)
422c18cb 7329 {
fac5aff3 7330 tree inside_type = TREE_TYPE (TREE_OPERAND (op0, 0));
7331 tree inter_type = TREE_TYPE (op0);
422c18cb 7332 int inside_int = INTEGRAL_TYPE_P (inside_type);
7333 int inside_ptr = POINTER_TYPE_P (inside_type);
7334 int inside_float = FLOAT_TYPE_P (inside_type);
6ff828af 7335 int inside_vec = TREE_CODE (inside_type) == VECTOR_TYPE;
422c18cb 7336 unsigned int inside_prec = TYPE_PRECISION (inside_type);
7337 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
7338 int inter_int = INTEGRAL_TYPE_P (inter_type);
7339 int inter_ptr = POINTER_TYPE_P (inter_type);
7340 int inter_float = FLOAT_TYPE_P (inter_type);
6ff828af 7341 int inter_vec = TREE_CODE (inter_type) == VECTOR_TYPE;
422c18cb 7342 unsigned int inter_prec = TYPE_PRECISION (inter_type);
7343 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
7344 int final_int = INTEGRAL_TYPE_P (type);
7345 int final_ptr = POINTER_TYPE_P (type);
7346 int final_float = FLOAT_TYPE_P (type);
6ff828af 7347 int final_vec = TREE_CODE (type) == VECTOR_TYPE;
422c18cb 7348 unsigned int final_prec = TYPE_PRECISION (type);
7349 int final_unsignedp = TYPE_UNSIGNED (type);
7350
7351 /* In addition to the cases of two conversions in a row
7352 handled below, if we are converting something to its own
7353 type via an object of identical or wider precision, neither
7354 conversion is needed. */
7355 if (TYPE_MAIN_VARIANT (inside_type) == TYPE_MAIN_VARIANT (type)
219dad96 7356 && (((inter_int || inter_ptr) && final_int)
7357 || (inter_float && final_float))
422c18cb 7358 && inter_prec >= final_prec)
7ab7fd4f 7359 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
422c18cb 7360
7361 /* Likewise, if the intermediate and final types are either both
7362 float or both integer, we don't need the middle conversion if
7363 it is wider than the final type and doesn't change the signedness
7364 (for integers). Avoid this if the final type is a pointer
7365 since then we sometimes need the inner conversion. Likewise if
7366 the outer has a precision not equal to the size of its mode. */
7367 if ((((inter_int || inter_ptr) && (inside_int || inside_ptr))
6ff828af 7368 || (inter_float && inside_float)
7369 || (inter_vec && inside_vec))
422c18cb 7370 && inter_prec >= inside_prec
6ff828af 7371 && (inter_float || inter_vec
7372 || inter_unsignedp == inside_unsignedp)
422c18cb 7373 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7374 && TYPE_MODE (type) == TYPE_MODE (inter_type))
6ff828af 7375 && ! final_ptr
7376 && (! final_vec || inter_prec == inside_prec))
7ab7fd4f 7377 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
422c18cb 7378
7379 /* If we have a sign-extension of a zero-extended value, we can
7380 replace that by a single zero-extension. */
7381 if (inside_int && inter_int && final_int
7382 && inside_prec < inter_prec && inter_prec < final_prec
7383 && inside_unsignedp && !inter_unsignedp)
7ab7fd4f 7384 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
422c18cb 7385
7386 /* Two conversions in a row are not needed unless:
7387 - some conversion is floating-point (overstrict for now), or
6ff828af 7388 - some conversion is a vector (overstrict for now), or
422c18cb 7389 - the intermediate type is narrower than both initial and
7390 final, or
7391 - the intermediate type and innermost type differ in signedness,
7392 and the outermost type is wider than the intermediate, or
7393 - the initial type is a pointer type and the precisions of the
7394 intermediate and final types differ, or
7395 - the final type is a pointer type and the precisions of the
219dad96 7396 initial and intermediate types differ.
7397 - the final type is a pointer type and the initial type not
7398 - the initial type is a pointer to an array and the final type
7399 not. */
422c18cb 7400 if (! inside_float && ! inter_float && ! final_float
6ff828af 7401 && ! inside_vec && ! inter_vec && ! final_vec
219dad96 7402 && (inter_prec >= inside_prec || inter_prec >= final_prec)
422c18cb 7403 && ! (inside_int && inter_int
7404 && inter_unsignedp != inside_unsignedp
7405 && inter_prec < final_prec)
7406 && ((inter_unsignedp && inter_prec > inside_prec)
7407 == (final_unsignedp && final_prec > inter_prec))
7408 && ! (inside_ptr && inter_prec != final_prec)
7409 && ! (final_ptr && inside_prec != inter_prec)
7410 && ! (final_prec != GET_MODE_BITSIZE (TYPE_MODE (type))
7411 && TYPE_MODE (type) == TYPE_MODE (inter_type))
219dad96 7412 && final_ptr == inside_ptr
7413 && ! (inside_ptr
7414 && TREE_CODE (TREE_TYPE (inside_type)) == ARRAY_TYPE
7415 && TREE_CODE (TREE_TYPE (type)) != ARRAY_TYPE))
7ab7fd4f 7416 return fold_build1 (code, type, TREE_OPERAND (op0, 0));
422c18cb 7417 }
7418
73d9e97d 7419 /* Handle (T *)&A.B.C for A being of type T and B and C
23943319 7420 living at offset zero. This occurs frequently in
73d9e97d 7421 C++ upcasting and then accessing the base. */
7422 if (TREE_CODE (op0) == ADDR_EXPR
7423 && POINTER_TYPE_P (type)
7424 && handled_component_p (TREE_OPERAND (op0, 0)))
7425 {
7426 HOST_WIDE_INT bitsize, bitpos;
7427 tree offset;
7428 enum machine_mode mode;
7429 int unsignedp, volatilep;
7430 tree base = TREE_OPERAND (op0, 0);
7431 base = get_inner_reference (base, &bitsize, &bitpos, &offset,
7432 &mode, &unsignedp, &volatilep, false);
7433 /* If the reference was to a (constant) zero offset, we can use
7434 the address of the base if it has the same base type
7435 as the result type. */
7436 if (! offset && bitpos == 0
7437 && TYPE_MAIN_VARIANT (TREE_TYPE (type))
7438 == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
7439 return fold_convert (type, build_fold_addr_expr (base));
7440 }
7441
fac5aff3 7442 if (TREE_CODE (op0) == MODIFY_EXPR
7443 && TREE_CONSTANT (TREE_OPERAND (op0, 1))
422c18cb 7444 /* Detect assigning a bitfield. */
fac5aff3 7445 && !(TREE_CODE (TREE_OPERAND (op0, 0)) == COMPONENT_REF
7446 && DECL_BIT_FIELD (TREE_OPERAND (TREE_OPERAND (op0, 0), 1))))
422c18cb 7447 {
7448 /* Don't leave an assignment inside a conversion
7449 unless assigning a bitfield. */
b085d4e5 7450 tem = fold_build1 (code, type, TREE_OPERAND (op0, 1));
422c18cb 7451 /* First do the assignment, then return converted constant. */
b085d4e5 7452 tem = build2 (COMPOUND_EXPR, TREE_TYPE (tem), op0, tem);
422c18cb 7453 TREE_NO_WARNING (tem) = 1;
7454 TREE_USED (tem) = 1;
7455 return tem;
7456 }
7457
7458 /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
7459 constants (if x has signed type, the sign bit cannot be set
7460 in c). This folds extension into the BIT_AND_EXPR. */
7461 if (INTEGRAL_TYPE_P (type)
7462 && TREE_CODE (type) != BOOLEAN_TYPE
fac5aff3 7463 && TREE_CODE (op0) == BIT_AND_EXPR
7464 && TREE_CODE (TREE_OPERAND (op0, 1)) == INTEGER_CST)
422c18cb 7465 {
fac5aff3 7466 tree and = op0;
422c18cb 7467 tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
7468 int change = 0;
7469
7470 if (TYPE_UNSIGNED (TREE_TYPE (and))
7471 || (TYPE_PRECISION (type)
7472 <= TYPE_PRECISION (TREE_TYPE (and))))
7473 change = 1;
7474 else if (TYPE_PRECISION (TREE_TYPE (and1))
7475 <= HOST_BITS_PER_WIDE_INT
7476 && host_integerp (and1, 1))
7477 {
7478 unsigned HOST_WIDE_INT cst;
7479
7480 cst = tree_low_cst (and1, 1);
7481 cst &= (HOST_WIDE_INT) -1
7482 << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
7483 change = (cst == 0);
7484#ifdef LOAD_EXTEND_OP
7485 if (change
7486 && !flag_syntax_only
7487 && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
7488 == ZERO_EXTEND))
7489 {
7490 tree uns = lang_hooks.types.unsigned_type (TREE_TYPE (and0));
7491 and0 = fold_convert (uns, and0);
7492 and1 = fold_convert (uns, and1);
7493 }
7494#endif
7495 }
7496 if (change)
7497 {
7498 tem = build_int_cst_wide (type, TREE_INT_CST_LOW (and1),
7499 TREE_INT_CST_HIGH (and1));
7500 tem = force_fit_type (tem, 0, TREE_OVERFLOW (and1),
7501 TREE_CONSTANT_OVERFLOW (and1));
7ab7fd4f 7502 return fold_build2 (BIT_AND_EXPR, type,
7503 fold_convert (type, and0), tem);
422c18cb 7504 }
7505 }
7506
7507 /* Convert (T1)((T2)X op Y) into (T1)X op Y, for pointer types T1 and
7508 T2 being pointers to types of the same size. */
fac5aff3 7509 if (POINTER_TYPE_P (type)
422c18cb 7510 && BINARY_CLASS_P (arg0)
7511 && TREE_CODE (TREE_OPERAND (arg0, 0)) == NOP_EXPR
7512 && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))))
7513 {
7514 tree arg00 = TREE_OPERAND (arg0, 0);
fac5aff3 7515 tree t0 = type;
422c18cb 7516 tree t1 = TREE_TYPE (arg00);
7517 tree tt0 = TREE_TYPE (t0);
7518 tree tt1 = TREE_TYPE (t1);
7519 tree s0 = TYPE_SIZE (tt0);
7520 tree s1 = TYPE_SIZE (tt1);
7521
7522 if (s0 && s1 && operand_equal_p (s0, s1, OEP_ONLY_CONST))
7523 return build2 (TREE_CODE (arg0), t0, fold_convert (t0, arg00),
7524 TREE_OPERAND (arg0, 1));
7525 }
7526
c348f27f 7527 /* Convert (T1)(~(T2)X) into ~(T1)X if T1 and T2 are integral types
7528 of the same precision, and X is a integer type not narrower than
7529 types T1 or T2, i.e. the cast (T2)X isn't an extension. */
7530 if (INTEGRAL_TYPE_P (type)
7531 && TREE_CODE (op0) == BIT_NOT_EXPR
7532 && INTEGRAL_TYPE_P (TREE_TYPE (op0))
7533 && (TREE_CODE (TREE_OPERAND (op0, 0)) == NOP_EXPR
7534 || TREE_CODE (TREE_OPERAND (op0, 0)) == CONVERT_EXPR)
7535 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (op0)))
7536 {
7537 tem = TREE_OPERAND (TREE_OPERAND (op0, 0), 0);
7538 if (INTEGRAL_TYPE_P (TREE_TYPE (tem))
7539 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (tem)))
7540 return fold_build1 (BIT_NOT_EXPR, type, fold_convert (type, tem));
7541 }
7542
422c18cb 7543 tem = fold_convert_const (code, type, arg0);
e7edfbbd 7544 return tem ? tem : NULL_TREE;
422c18cb 7545
7546 case VIEW_CONVERT_EXPR:
fac5aff3 7547 if (TREE_CODE (op0) == VIEW_CONVERT_EXPR)
5f4092ed 7548 return fold_build1 (VIEW_CONVERT_EXPR, type, TREE_OPERAND (op0, 0));
7549 return fold_view_convert_expr (type, op0);
422c18cb 7550
7551 case NEGATE_EXPR:
58b22aa6 7552 tem = fold_negate_expr (arg0);
7553 if (tem)
7554 return fold_convert (type, tem);
e7edfbbd 7555 return NULL_TREE;
422c18cb 7556
7557 case ABS_EXPR:
7558 if (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST)
7559 return fold_abs_const (arg0, type);
7560 else if (TREE_CODE (arg0) == NEGATE_EXPR)
7ab7fd4f 7561 return fold_build1 (ABS_EXPR, type, TREE_OPERAND (arg0, 0));
422c18cb 7562 /* Convert fabs((double)float) into (double)fabsf(float). */
7563 else if (TREE_CODE (arg0) == NOP_EXPR
7564 && TREE_CODE (type) == REAL_TYPE)
7565 {
7566 tree targ0 = strip_float_extensions (arg0);
7567 if (targ0 != arg0)
7ab7fd4f 7568 return fold_convert (type, fold_build1 (ABS_EXPR,
7569 TREE_TYPE (targ0),
7570 targ0));
422c18cb 7571 }
8040d1c5 7572 /* ABS_EXPR<ABS_EXPR<x>> = ABS_EXPR<x> even if flag_wrapv is on. */
7573 else if (tree_expr_nonnegative_p (arg0) || TREE_CODE (arg0) == ABS_EXPR)
422c18cb 7574 return arg0;
7575
7576 /* Strip sign ops from argument. */
7577 if (TREE_CODE (type) == REAL_TYPE)
7578 {
7579 tem = fold_strip_sign_ops (arg0);
7580 if (tem)
7ab7fd4f 7581 return fold_build1 (ABS_EXPR, type, fold_convert (type, tem));
422c18cb 7582 }
e7edfbbd 7583 return NULL_TREE;
422c18cb 7584
7585 case CONJ_EXPR:
7586 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7587 return fold_convert (type, arg0);
75e3ef6e 7588 if (TREE_CODE (arg0) == COMPLEX_EXPR)
7589 {
7590 tree itype = TREE_TYPE (type);
7591 tree rpart = fold_convert (itype, TREE_OPERAND (arg0, 0));
7592 tree ipart = fold_convert (itype, TREE_OPERAND (arg0, 1));
7593 return fold_build2 (COMPLEX_EXPR, type, rpart, negate_expr (ipart));
7594 }
7595 if (TREE_CODE (arg0) == COMPLEX_CST)
7596 {
7597 tree itype = TREE_TYPE (type);
7598 tree rpart = fold_convert (itype, TREE_REALPART (arg0));
7599 tree ipart = fold_convert (itype, TREE_IMAGPART (arg0));
7600 return build_complex (type, rpart, negate_expr (ipart));
7601 }
7602 if (TREE_CODE (arg0) == CONJ_EXPR)
7603 return fold_convert (type, TREE_OPERAND (arg0, 0));
e7edfbbd 7604 return NULL_TREE;
422c18cb 7605
7606 case BIT_NOT_EXPR:
7607 if (TREE_CODE (arg0) == INTEGER_CST)
7608 return fold_not_const (arg0, type);
7609 else if (TREE_CODE (arg0) == BIT_NOT_EXPR)
7610 return TREE_OPERAND (arg0, 0);
7611 /* Convert ~ (-A) to A - 1. */
7612 else if (INTEGRAL_TYPE_P (type) && TREE_CODE (arg0) == NEGATE_EXPR)
7ab7fd4f 7613 return fold_build2 (MINUS_EXPR, type, TREE_OPERAND (arg0, 0),
7614 build_int_cst (type, 1));
422c18cb 7615 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
7616 else if (INTEGRAL_TYPE_P (type)
7617 && ((TREE_CODE (arg0) == MINUS_EXPR
7618 && integer_onep (TREE_OPERAND (arg0, 1)))
7619 || (TREE_CODE (arg0) == PLUS_EXPR
7620 && integer_all_onesp (TREE_OPERAND (arg0, 1)))))
7ab7fd4f 7621 return fold_build1 (NEGATE_EXPR, type, TREE_OPERAND (arg0, 0));
039f212d 7622 /* Convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
7623 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7624 && (tem = fold_unary (BIT_NOT_EXPR, type,
7625 fold_convert (type,
7626 TREE_OPERAND (arg0, 0)))))
7627 return fold_build2 (BIT_XOR_EXPR, type, tem,
7628 fold_convert (type, TREE_OPERAND (arg0, 1)));
7629 else if (TREE_CODE (arg0) == BIT_XOR_EXPR
7630 && (tem = fold_unary (BIT_NOT_EXPR, type,
7631 fold_convert (type,
7632 TREE_OPERAND (arg0, 1)))))
7633 return fold_build2 (BIT_XOR_EXPR, type,
7634 fold_convert (type, TREE_OPERAND (arg0, 0)), tem);
7635
e7edfbbd 7636 return NULL_TREE;
422c18cb 7637
7638 case TRUTH_NOT_EXPR:
7639 /* The argument to invert_truthvalue must have Boolean type. */
7640 if (TREE_CODE (TREE_TYPE (arg0)) != BOOLEAN_TYPE)
7641 arg0 = fold_convert (boolean_type_node, arg0);
7642
7643 /* Note that the operand of this must be an int
7644 and its values must be 0 or 1.
7645 ("true" is a fixed value perhaps depending on the language,
7646 but we don't handle values other than 1 correctly yet.) */
6758b11c 7647 tem = fold_truth_not_expr (arg0);
7648 if (!tem)
e7edfbbd 7649 return NULL_TREE;
422c18cb 7650 return fold_convert (type, tem);
7651
7652 case REALPART_EXPR:
7653 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
75e3ef6e 7654 return fold_convert (type, arg0);
7655 if (TREE_CODE (arg0) == COMPLEX_EXPR)
422c18cb 7656 return omit_one_operand (type, TREE_OPERAND (arg0, 0),
7657 TREE_OPERAND (arg0, 1));
75e3ef6e 7658 if (TREE_CODE (arg0) == COMPLEX_CST)
7659 return fold_convert (type, TREE_REALPART (arg0));
7660 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7661 {
7662 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7663 tem = fold_build2 (TREE_CODE (arg0), itype,
7664 fold_build1 (REALPART_EXPR, itype,
7665 TREE_OPERAND (arg0, 0)),
7666 fold_build1 (REALPART_EXPR, itype,
7667 TREE_OPERAND (arg0, 1)));
7668 return fold_convert (type, tem);
7669 }
7670 if (TREE_CODE (arg0) == CONJ_EXPR)
7671 {
7672 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7673 tem = fold_build1 (REALPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7674 return fold_convert (type, tem);
7675 }
e7edfbbd 7676 return NULL_TREE;
422c18cb 7677
7678 case IMAGPART_EXPR:
7679 if (TREE_CODE (TREE_TYPE (arg0)) != COMPLEX_TYPE)
7680 return fold_convert (type, integer_zero_node);
75e3ef6e 7681 if (TREE_CODE (arg0) == COMPLEX_EXPR)
422c18cb 7682 return omit_one_operand (type, TREE_OPERAND (arg0, 1),
7683 TREE_OPERAND (arg0, 0));
75e3ef6e 7684 if (TREE_CODE (arg0) == COMPLEX_CST)
7685 return fold_convert (type, TREE_IMAGPART (arg0));
7686 if (TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR)
7687 {
7688 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7689 tem = fold_build2 (TREE_CODE (arg0), itype,
7690 fold_build1 (IMAGPART_EXPR, itype,
7691 TREE_OPERAND (arg0, 0)),
7692 fold_build1 (IMAGPART_EXPR, itype,
7693 TREE_OPERAND (arg0, 1)));
7694 return fold_convert (type, tem);
7695 }
7696 if (TREE_CODE (arg0) == CONJ_EXPR)
7697 {
7698 tree itype = TREE_TYPE (TREE_TYPE (arg0));
7699 tem = fold_build1 (IMAGPART_EXPR, itype, TREE_OPERAND (arg0, 0));
7700 return fold_convert (type, negate_expr (tem));
7701 }
e7edfbbd 7702 return NULL_TREE;
422c18cb 7703
7704 default:
e7edfbbd 7705 return NULL_TREE;
422c18cb 7706 } /* switch (code) */
7707}
7708
7e50ecae 7709/* Fold a binary expression of code CODE and type TYPE with operands
7710 OP0 and OP1, containing either a MIN-MAX or a MAX-MIN combination.
7711 Return the folded expression if folding is successful. Otherwise,
7712 return NULL_TREE. */
7713
7714static tree
7715fold_minmax (enum tree_code code, tree type, tree op0, tree op1)
7716{
7717 enum tree_code compl_code;
7718
7719 if (code == MIN_EXPR)
7720 compl_code = MAX_EXPR;
7721 else if (code == MAX_EXPR)
7722 compl_code = MIN_EXPR;
7723 else
d9560eb6 7724 gcc_unreachable ();
7e50ecae 7725
7726