re PR middle-end/67120 (wrong code for volatile pointers at -O1 and above on x86_64...
[gcc.git] / gcc / match.pd
1 /* Match-and-simplify patterns for shared GENERIC and GIMPLE folding.
2 This file is consumed by genmatch which produces gimple-match.c
3 and generic-match.c from it.
4
5 Copyright (C) 2014-2015 Free Software Foundation, Inc.
6 Contributed by Richard Biener <rguenther@suse.de>
7 and Prathamesh Kulkarni <bilbotheelffriend@gmail.com>
8
9 This file is part of GCC.
10
11 GCC is free software; you can redistribute it and/or modify it under
12 the terms of the GNU General Public License as published by the Free
13 Software Foundation; either version 3, or (at your option) any later
14 version.
15
16 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
17 WARRANTY; without even the implied warranty of MERCHANTABILITY or
18 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
19 for more details.
20
21 You should have received a copy of the GNU General Public License
22 along with GCC; see the file COPYING3. If not see
23 <http://www.gnu.org/licenses/>. */
24
25
26 /* Generic tree predicates we inherit. */
27 (define_predicates
28 integer_onep integer_zerop integer_all_onesp integer_minus_onep
29 integer_each_onep integer_truep integer_nonzerop
30 real_zerop real_onep real_minus_onep
31 CONSTANT_CLASS_P
32 tree_expr_nonnegative_p
33 integer_pow2p
34 HONOR_NANS)
35
36 /* Operator lists. */
37 (define_operator_list tcc_comparison
38 lt le eq ne ge gt unordered ordered unlt unle ungt unge uneq ltgt)
39 (define_operator_list inverted_tcc_comparison
40 ge gt ne eq lt le ordered unordered ge gt le lt ltgt uneq)
41 (define_operator_list inverted_tcc_comparison_with_nans
42 unge ungt ne eq unlt unle ordered unordered ge gt le lt ltgt uneq)
43 (define_operator_list swapped_tcc_comparison
44 gt ge eq ne le lt unordered ordered ungt unge unlt unle uneq ltgt)
45 (define_operator_list simple_comparison lt le eq ne ge gt)
46 (define_operator_list swapped_simple_comparison gt ge eq ne le lt)
47
48 (define_operator_list LOG BUILT_IN_LOGF BUILT_IN_LOG BUILT_IN_LOGL)
49 (define_operator_list EXP BUILT_IN_EXPF BUILT_IN_EXP BUILT_IN_EXPL)
50 (define_operator_list LOG2 BUILT_IN_LOG2F BUILT_IN_LOG2 BUILT_IN_LOG2L)
51 (define_operator_list EXP2 BUILT_IN_EXP2F BUILT_IN_EXP2 BUILT_IN_EXP2L)
52 (define_operator_list LOG10 BUILT_IN_LOG10F BUILT_IN_LOG10 BUILT_IN_LOG10L)
53 (define_operator_list EXP10 BUILT_IN_EXP10F BUILT_IN_EXP10 BUILT_IN_EXP10L)
54 (define_operator_list POW BUILT_IN_POWF BUILT_IN_POW BUILT_IN_POWL)
55 (define_operator_list POW10 BUILT_IN_POW10F BUILT_IN_POW10 BUILT_IN_POW10L)
56 (define_operator_list SQRT BUILT_IN_SQRTF BUILT_IN_SQRT BUILT_IN_SQRTL)
57 (define_operator_list CBRT BUILT_IN_CBRTF BUILT_IN_CBRT BUILT_IN_CBRTL)
58
59
60 /* Simplifications of operations with one constant operand and
61 simplifications to constants or single values. */
62
63 (for op (plus pointer_plus minus bit_ior bit_xor)
64 (simplify
65 (op @0 integer_zerop)
66 (non_lvalue @0)))
67
68 /* 0 +p index -> (type)index */
69 (simplify
70 (pointer_plus integer_zerop @1)
71 (non_lvalue (convert @1)))
72
73 /* See if ARG1 is zero and X + ARG1 reduces to X.
74 Likewise if the operands are reversed. */
75 (simplify
76 (plus:c @0 real_zerop@1)
77 (if (fold_real_zero_addition_p (type, @1, 0))
78 (non_lvalue @0)))
79
80 /* See if ARG1 is zero and X - ARG1 reduces to X. */
81 (simplify
82 (minus @0 real_zerop@1)
83 (if (fold_real_zero_addition_p (type, @1, 1))
84 (non_lvalue @0)))
85
86 /* Simplify x - x.
87 This is unsafe for certain floats even in non-IEEE formats.
88 In IEEE, it is unsafe because it does wrong for NaNs.
89 Also note that operand_equal_p is always false if an operand
90 is volatile. */
91 (simplify
92 (minus @0 @0)
93 (if (!FLOAT_TYPE_P (type) || !HONOR_NANS (type))
94 { build_zero_cst (type); }))
95
96 (simplify
97 (mult @0 integer_zerop@1)
98 @1)
99
100 /* Maybe fold x * 0 to 0. The expressions aren't the same
101 when x is NaN, since x * 0 is also NaN. Nor are they the
102 same in modes with signed zeros, since multiplying a
103 negative value by 0 gives -0, not +0. */
104 (simplify
105 (mult @0 real_zerop@1)
106 (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (type))
107 @1))
108
109 /* In IEEE floating point, x*1 is not equivalent to x for snans.
110 Likewise for complex arithmetic with signed zeros. */
111 (simplify
112 (mult @0 real_onep)
113 (if (!HONOR_SNANS (type)
114 && (!HONOR_SIGNED_ZEROS (type)
115 || !COMPLEX_FLOAT_TYPE_P (type)))
116 (non_lvalue @0)))
117
118 /* Transform x * -1.0 into -x. */
119 (simplify
120 (mult @0 real_minus_onep)
121 (if (!HONOR_SNANS (type)
122 && (!HONOR_SIGNED_ZEROS (type)
123 || !COMPLEX_FLOAT_TYPE_P (type)))
124 (negate @0)))
125
126 /* Make sure to preserve divisions by zero. This is the reason why
127 we don't simplify x / x to 1 or 0 / x to 0. */
128 (for op (mult trunc_div ceil_div floor_div round_div exact_div)
129 (simplify
130 (op @0 integer_onep)
131 (non_lvalue @0)))
132
133 /* X / -1 is -X. */
134 (for div (trunc_div ceil_div floor_div round_div exact_div)
135 (simplify
136 (div @0 integer_minus_onep@1)
137 (if (!TYPE_UNSIGNED (type))
138 (negate @0))))
139
140 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
141 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
142 (simplify
143 (floor_div @0 @1)
144 (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
145 && TYPE_UNSIGNED (type))
146 (trunc_div @0 @1)))
147
148 /* Combine two successive divisions. Note that combining ceil_div
149 and floor_div is trickier and combining round_div even more so. */
150 (for div (trunc_div exact_div)
151 (simplify
152 (div (div @0 INTEGER_CST@1) INTEGER_CST@2)
153 (with {
154 bool overflow_p;
155 wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p);
156 }
157 (if (!overflow_p)
158 (div @0 { wide_int_to_tree (type, mul); })
159 (if (TYPE_UNSIGNED (type)
160 || mul != wi::min_value (TYPE_PRECISION (type), SIGNED))
161 { build_zero_cst (type); })))))
162
163 /* Optimize A / A to 1.0 if we don't care about
164 NaNs or Infinities. */
165 (simplify
166 (rdiv @0 @0)
167 (if (FLOAT_TYPE_P (type)
168 && ! HONOR_NANS (type)
169 && ! HONOR_INFINITIES (type))
170 { build_one_cst (type); }))
171
172 /* Optimize -A / A to -1.0 if we don't care about
173 NaNs or Infinities. */
174 (simplify
175 (rdiv:c @0 (negate @0))
176 (if (FLOAT_TYPE_P (type)
177 && ! HONOR_NANS (type)
178 && ! HONOR_INFINITIES (type))
179 { build_minus_one_cst (type); }))
180
181 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
182 (simplify
183 (rdiv @0 real_onep)
184 (if (!HONOR_SNANS (type))
185 (non_lvalue @0)))
186
187 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
188 (simplify
189 (rdiv @0 real_minus_onep)
190 (if (!HONOR_SNANS (type))
191 (negate @0)))
192
193 /* If ARG1 is a constant, we can convert this to a multiply by the
194 reciprocal. This does not have the same rounding properties,
195 so only do this if -freciprocal-math. We can actually
196 always safely do it if ARG1 is a power of two, but it's hard to
197 tell if it is or not in a portable manner. */
198 (for cst (REAL_CST COMPLEX_CST VECTOR_CST)
199 (simplify
200 (rdiv @0 cst@1)
201 (if (optimize)
202 (if (flag_reciprocal_math
203 && !real_zerop (@1))
204 (with
205 { tree tem = const_binop (RDIV_EXPR, type, build_one_cst (type), @1); }
206 (if (tem)
207 (mult @0 { tem; } )))
208 (if (cst != COMPLEX_CST)
209 (with { tree inverse = exact_inverse (type, @1); }
210 (if (inverse)
211 (mult @0 { inverse; } ))))))))
212
213 /* Same applies to modulo operations, but fold is inconsistent here
214 and simplifies 0 % x to 0, only preserving literal 0 % 0. */
215 (for mod (ceil_mod floor_mod round_mod trunc_mod)
216 /* 0 % X is always zero. */
217 (simplify
218 (mod integer_zerop@0 @1)
219 /* But not for 0 % 0 so that we can get the proper warnings and errors. */
220 (if (!integer_zerop (@1))
221 @0))
222 /* X % 1 is always zero. */
223 (simplify
224 (mod @0 integer_onep)
225 { build_zero_cst (type); })
226 /* X % -1 is zero. */
227 (simplify
228 (mod @0 integer_minus_onep@1)
229 (if (!TYPE_UNSIGNED (type))
230 { build_zero_cst (type); }))
231 /* (X % Y) % Y is just X % Y. */
232 (simplify
233 (mod (mod@2 @0 @1) @1)
234 @2)
235 /* From extract_muldiv_1: (X * C1) % C2 is zero if C1 is a multiple of C2. */
236 (simplify
237 (mod (mult @0 INTEGER_CST@1) INTEGER_CST@2)
238 (if (ANY_INTEGRAL_TYPE_P (type)
239 && TYPE_OVERFLOW_UNDEFINED (type)
240 && wi::multiple_of_p (@1, @2, TYPE_SIGN (type)))
241 { build_zero_cst (type); })))
242
243 /* X % -C is the same as X % C. */
244 (simplify
245 (trunc_mod @0 INTEGER_CST@1)
246 (if (TYPE_SIGN (type) == SIGNED
247 && !TREE_OVERFLOW (@1)
248 && wi::neg_p (@1)
249 && !TYPE_OVERFLOW_TRAPS (type)
250 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
251 && !sign_bit_p (@1, @1))
252 (trunc_mod @0 (negate @1))))
253
254 /* X % -Y is the same as X % Y. */
255 (simplify
256 (trunc_mod @0 (convert? (negate @1)))
257 (if (!TYPE_UNSIGNED (type)
258 && !TYPE_OVERFLOW_TRAPS (type)
259 && tree_nop_conversion_p (type, TREE_TYPE (@1)))
260 (trunc_mod @0 (convert @1))))
261
262 /* X - (X / Y) * Y is the same as X % Y. */
263 (simplify
264 (minus (convert1? @0) (convert2? (mult (trunc_div @0 @1) @1)))
265 (if (INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
266 (trunc_mod (convert @0) (convert @1))))
267
268 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
269 i.e. "X % C" into "X & (C - 1)", if X and C are positive.
270 Also optimize A % (C << N) where C is a power of 2,
271 to A & ((C << N) - 1). */
272 (match (power_of_two_cand @1)
273 INTEGER_CST@1)
274 (match (power_of_two_cand @1)
275 (lshift INTEGER_CST@1 @2))
276 (for mod (trunc_mod floor_mod)
277 (simplify
278 (mod @0 (convert?@3 (power_of_two_cand@1 @2)))
279 (if ((TYPE_UNSIGNED (type)
280 || tree_expr_nonnegative_p (@0))
281 && tree_nop_conversion_p (type, TREE_TYPE (@3))
282 && integer_pow2p (@2) && tree_int_cst_sgn (@2) > 0)
283 (bit_and @0 (convert (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))))
284
285 /* Simplify (unsigned t * 2)/2 -> unsigned t & 0x7FFFFFFF. */
286 (simplify
287 (trunc_div (mult @0 integer_pow2p@1) @1)
288 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
289 (bit_and @0 { wide_int_to_tree
290 (type, wi::mask (TYPE_PRECISION (type) - wi::exact_log2 (@1),
291 false, TYPE_PRECISION (type))); })))
292
293 /* Simplify (unsigned t / 2) * 2 -> unsigned t & ~1. */
294 (simplify
295 (mult (trunc_div @0 integer_pow2p@1) @1)
296 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
297 (bit_and @0 (negate @1))))
298
299 /* X % Y is smaller than Y. */
300 (for cmp (lt ge)
301 (simplify
302 (cmp (trunc_mod @0 @1) @1)
303 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
304 { constant_boolean_node (cmp == LT_EXPR, type); })))
305 (for cmp (gt le)
306 (simplify
307 (cmp @1 (trunc_mod @0 @1))
308 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
309 { constant_boolean_node (cmp == GT_EXPR, type); })))
310
311 /* x | ~0 -> ~0 */
312 (simplify
313 (bit_ior @0 integer_all_onesp@1)
314 @1)
315
316 /* x & 0 -> 0 */
317 (simplify
318 (bit_and @0 integer_zerop@1)
319 @1)
320
321 /* ~x | x -> -1 */
322 /* ~x ^ x -> -1 */
323 /* ~x + x -> -1 */
324 (for op (bit_ior bit_xor plus)
325 (simplify
326 (op:c (convert? @0) (convert? (bit_not @0)))
327 (convert { build_all_ones_cst (TREE_TYPE (@0)); })))
328
329 /* x ^ x -> 0 */
330 (simplify
331 (bit_xor @0 @0)
332 { build_zero_cst (type); })
333
334 /* Canonicalize X ^ ~0 to ~X. */
335 (simplify
336 (bit_xor @0 integer_all_onesp@1)
337 (bit_not @0))
338
339 /* x & ~0 -> x */
340 (simplify
341 (bit_and @0 integer_all_onesp)
342 (non_lvalue @0))
343
344 /* x & x -> x, x | x -> x */
345 (for bitop (bit_and bit_ior)
346 (simplify
347 (bitop @0 @0)
348 (non_lvalue @0)))
349
350 /* x + (x & 1) -> (x + 1) & ~1 */
351 (simplify
352 (plus:c @0 (bit_and:s @0 integer_onep@1))
353 (bit_and (plus @0 @1) (bit_not @1)))
354
355 /* x & ~(x & y) -> x & ~y */
356 /* x | ~(x | y) -> x | ~y */
357 (for bitop (bit_and bit_ior)
358 (simplify
359 (bitop:c @0 (bit_not (bitop:cs @0 @1)))
360 (bitop @0 (bit_not @1))))
361
362 /* (x | y) & ~x -> y & ~x */
363 /* (x & y) | ~x -> y | ~x */
364 (for bitop (bit_and bit_ior)
365 rbitop (bit_ior bit_and)
366 (simplify
367 (bitop:c (rbitop:c @0 @1) (bit_not@2 @0))
368 (bitop @1 @2)))
369
370 /* (x & y) ^ (x | y) -> x ^ y */
371 (simplify
372 (bit_xor:c (bit_and @0 @1) (bit_ior @0 @1))
373 (bit_xor @0 @1))
374
375 /* (x ^ y) ^ (x | y) -> x & y */
376 (simplify
377 (bit_xor:c (bit_xor @0 @1) (bit_ior @0 @1))
378 (bit_and @0 @1))
379
380 /* (x & y) + (x ^ y) -> x | y */
381 /* (x & y) | (x ^ y) -> x | y */
382 /* (x & y) ^ (x ^ y) -> x | y */
383 (for op (plus bit_ior bit_xor)
384 (simplify
385 (op:c (bit_and @0 @1) (bit_xor @0 @1))
386 (bit_ior @0 @1)))
387
388 /* (x & y) + (x | y) -> x + y */
389 (simplify
390 (plus:c (bit_and @0 @1) (bit_ior @0 @1))
391 (plus @0 @1))
392
393 /* (x + y) - (x | y) -> x & y */
394 (simplify
395 (minus (plus @0 @1) (bit_ior @0 @1))
396 (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
397 && !TYPE_SATURATING (type))
398 (bit_and @0 @1)))
399
400 /* (x + y) - (x & y) -> x | y */
401 (simplify
402 (minus (plus @0 @1) (bit_and @0 @1))
403 (if (!TYPE_OVERFLOW_SANITIZED (type) && !TYPE_OVERFLOW_TRAPS (type)
404 && !TYPE_SATURATING (type))
405 (bit_ior @0 @1)))
406
407 /* (x | y) - (x ^ y) -> x & y */
408 (simplify
409 (minus (bit_ior @0 @1) (bit_xor @0 @1))
410 (bit_and @0 @1))
411
412 /* (x | y) - (x & y) -> x ^ y */
413 (simplify
414 (minus (bit_ior @0 @1) (bit_and @0 @1))
415 (bit_xor @0 @1))
416
417 /* (x | y) & ~(x & y) -> x ^ y */
418 (simplify
419 (bit_and:c (bit_ior @0 @1) (bit_not (bit_and @0 @1)))
420 (bit_xor @0 @1))
421
422 /* (x | y) & (~x ^ y) -> x & y */
423 (simplify
424 (bit_and:c (bit_ior:c @0 @1) (bit_xor:c @1 (bit_not @0)))
425 (bit_and @0 @1))
426
427 /* ~x & ~y -> ~(x | y)
428 ~x | ~y -> ~(x & y) */
429 (for op (bit_and bit_ior)
430 rop (bit_ior bit_and)
431 (simplify
432 (op (convert1? (bit_not @0)) (convert2? (bit_not @1)))
433 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
434 && tree_nop_conversion_p (type, TREE_TYPE (@1)))
435 (bit_not (rop (convert @0) (convert @1))))))
436
437 /* If we are XORing or adding two BIT_AND_EXPR's, both of which are and'ing
438 with a constant, and the two constants have no bits in common,
439 we should treat this as a BIT_IOR_EXPR since this may produce more
440 simplifications. */
441 (for op (bit_xor plus)
442 (simplify
443 (op (convert1? (bit_and@4 @0 INTEGER_CST@1))
444 (convert2? (bit_and@5 @2 INTEGER_CST@3)))
445 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
446 && tree_nop_conversion_p (type, TREE_TYPE (@2))
447 && wi::bit_and (@1, @3) == 0)
448 (bit_ior (convert @4) (convert @5)))))
449
450 /* (X | Y) ^ X -> Y & ~ X*/
451 (simplify
452 (bit_xor:c (convert? (bit_ior:c @0 @1)) (convert? @0))
453 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
454 (convert (bit_and @1 (bit_not @0)))))
455
456 /* Convert ~X ^ ~Y to X ^ Y. */
457 (simplify
458 (bit_xor (convert1? (bit_not @0)) (convert2? (bit_not @1)))
459 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
460 && tree_nop_conversion_p (type, TREE_TYPE (@1)))
461 (bit_xor (convert @0) (convert @1))))
462
463 /* Convert ~X ^ C to X ^ ~C. */
464 (simplify
465 (bit_xor (convert? (bit_not @0)) INTEGER_CST@1)
466 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
467 (bit_xor (convert @0) (bit_not @1))))
468
469 /* Fold (X & Y) ^ Y as ~X & Y. */
470 (simplify
471 (bit_xor:c (bit_and:c @0 @1) @1)
472 (bit_and (bit_not @0) @1))
473
474 /* Given a bit-wise operation CODE applied to ARG0 and ARG1, see if both
475 operands are another bit-wise operation with a common input. If so,
476 distribute the bit operations to save an operation and possibly two if
477 constants are involved. For example, convert
478 (A | B) & (A | C) into A | (B & C)
479 Further simplification will occur if B and C are constants. */
480 (for op (bit_and bit_ior)
481 rop (bit_ior bit_and)
482 (simplify
483 (op (convert? (rop:c @0 @1)) (convert? (rop @0 @2)))
484 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
485 (rop (convert @0) (op (convert @1) (convert @2))))))
486
487
488 (simplify
489 (abs (abs@1 @0))
490 @1)
491 (simplify
492 (abs (negate @0))
493 (abs @0))
494 (simplify
495 (abs tree_expr_nonnegative_p@0)
496 @0)
497
498 /* A few cases of fold-const.c negate_expr_p predicate. */
499 (match negate_expr_p
500 INTEGER_CST
501 (if ((INTEGRAL_TYPE_P (type)
502 && TYPE_OVERFLOW_WRAPS (type))
503 || (!TYPE_OVERFLOW_SANITIZED (type)
504 && may_negate_without_overflow_p (t)))))
505 (match negate_expr_p
506 FIXED_CST)
507 (match negate_expr_p
508 (negate @0)
509 (if (!TYPE_OVERFLOW_SANITIZED (type))))
510 (match negate_expr_p
511 REAL_CST
512 (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (t)))))
513 /* VECTOR_CST handling of non-wrapping types would recurse in unsupported
514 ways. */
515 (match negate_expr_p
516 VECTOR_CST
517 (if (FLOAT_TYPE_P (TREE_TYPE (type)) || TYPE_OVERFLOW_WRAPS (type))))
518
519 /* -(A + B) -> (-B) - A. */
520 (simplify
521 (negate (plus:c @0 negate_expr_p@1))
522 (if (!HONOR_SIGN_DEPENDENT_ROUNDING (element_mode (type))
523 && !HONOR_SIGNED_ZEROS (element_mode (type)))
524 (minus (negate @1) @0)))
525
526 /* A - B -> A + (-B) if B is easily negatable. */
527 (simplify
528 (minus @0 negate_expr_p@1)
529 (if (!FIXED_POINT_TYPE_P (type))
530 (plus @0 (negate @1))))
531
532 /* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
533 when profitable.
534 For bitwise binary operations apply operand conversions to the
535 binary operation result instead of to the operands. This allows
536 to combine successive conversions and bitwise binary operations.
537 We combine the above two cases by using a conditional convert. */
538 (for bitop (bit_and bit_ior bit_xor)
539 (simplify
540 (bitop (convert @0) (convert? @1))
541 (if (((TREE_CODE (@1) == INTEGER_CST
542 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
543 && int_fits_type_p (@1, TREE_TYPE (@0)))
544 || types_match (@0, @1))
545 /* ??? This transform conflicts with fold-const.c doing
546 Convert (T)(x & c) into (T)x & (T)c, if c is an integer
547 constants (if x has signed type, the sign bit cannot be set
548 in c). This folds extension into the BIT_AND_EXPR.
549 Restrict it to GIMPLE to avoid endless recursions. */
550 && (bitop != BIT_AND_EXPR || GIMPLE)
551 && (/* That's a good idea if the conversion widens the operand, thus
552 after hoisting the conversion the operation will be narrower. */
553 TYPE_PRECISION (TREE_TYPE (@0)) < TYPE_PRECISION (type)
554 /* It's also a good idea if the conversion is to a non-integer
555 mode. */
556 || GET_MODE_CLASS (TYPE_MODE (type)) != MODE_INT
557 /* Or if the precision of TO is not the same as the precision
558 of its mode. */
559 || TYPE_PRECISION (type) != GET_MODE_PRECISION (TYPE_MODE (type))))
560 (convert (bitop @0 (convert @1))))))
561
562 (for bitop (bit_and bit_ior)
563 rbitop (bit_ior bit_and)
564 /* (x | y) & x -> x */
565 /* (x & y) | x -> x */
566 (simplify
567 (bitop:c (rbitop:c @0 @1) @0)
568 @0)
569 /* (~x | y) & x -> x & y */
570 /* (~x & y) | x -> x | y */
571 (simplify
572 (bitop:c (rbitop:c (bit_not @0) @1) @0)
573 (bitop @0 @1)))
574
575 /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */
576 (for bitop (bit_and bit_ior bit_xor)
577 (simplify
578 (bitop (bit_and:c @0 @1) (bit_and @2 @1))
579 (bit_and (bitop @0 @2) @1)))
580
581 /* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
582 (simplify
583 (bit_and (bit_ior @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
584 (bit_ior (bit_and @0 @2) (bit_and @1 @2)))
585
586 /* Combine successive equal operations with constants. */
587 (for bitop (bit_and bit_ior bit_xor)
588 (simplify
589 (bitop (bitop @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
590 (bitop @0 (bitop @1 @2))))
591
592 /* Try simple folding for X op !X, and X op X with the help
593 of the truth_valued_p and logical_inverted_value predicates. */
594 (match truth_valued_p
595 @0
596 (if (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1)))
597 (for op (tcc_comparison truth_and truth_andif truth_or truth_orif truth_xor)
598 (match truth_valued_p
599 (op @0 @1)))
600 (match truth_valued_p
601 (truth_not @0))
602
603 (match (logical_inverted_value @0)
604 (bit_not truth_valued_p@0))
605 (match (logical_inverted_value @0)
606 (eq @0 integer_zerop))
607 (match (logical_inverted_value @0)
608 (ne truth_valued_p@0 integer_truep))
609 (match (logical_inverted_value @0)
610 (bit_xor truth_valued_p@0 integer_truep))
611
612 /* X & !X -> 0. */
613 (simplify
614 (bit_and:c @0 (logical_inverted_value @0))
615 { build_zero_cst (type); })
616 /* X | !X and X ^ !X -> 1, , if X is truth-valued. */
617 (for op (bit_ior bit_xor)
618 (simplify
619 (op:c truth_valued_p@0 (logical_inverted_value @0))
620 { constant_boolean_node (true, type); }))
621 /* X ==/!= !X is false/true. */
622 (for op (eq ne)
623 (simplify
624 (op:c truth_valued_p@0 (logical_inverted_value @0))
625 { constant_boolean_node (op == NE_EXPR ? true : false, type); }))
626
627 /* If arg1 and arg2 are booleans (or any single bit type)
628 then try to simplify:
629
630 (~X & Y) -> X < Y
631 (X & ~Y) -> Y < X
632 (~X | Y) -> X <= Y
633 (X | ~Y) -> Y <= X
634
635 But only do this if our result feeds into a comparison as
636 this transformation is not always a win, particularly on
637 targets with and-not instructions.
638 -> simplify_bitwise_binary_boolean */
639 (simplify
640 (ne (bit_and:c (bit_not @0) @1) integer_zerop)
641 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
642 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
643 (lt @0 @1)))
644 (simplify
645 (ne (bit_ior:c (bit_not @0) @1) integer_zerop)
646 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
647 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
648 (le @0 @1)))
649
650 /* ~~x -> x */
651 (simplify
652 (bit_not (bit_not @0))
653 @0)
654
655 /* Convert ~ (-A) to A - 1. */
656 (simplify
657 (bit_not (convert? (negate @0)))
658 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
659 (convert (minus @0 { build_each_one_cst (TREE_TYPE (@0)); }))))
660
661 /* Convert ~ (A - 1) or ~ (A + -1) to -A. */
662 (simplify
663 (bit_not (convert? (minus @0 integer_each_onep)))
664 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
665 (convert (negate @0))))
666 (simplify
667 (bit_not (convert? (plus @0 integer_all_onesp)))
668 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
669 (convert (negate @0))))
670
671 /* Part of convert ~(X ^ Y) to ~X ^ Y or X ^ ~Y if ~X or ~Y simplify. */
672 (simplify
673 (bit_not (convert? (bit_xor @0 INTEGER_CST@1)))
674 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
675 (convert (bit_xor @0 (bit_not @1)))))
676 (simplify
677 (bit_not (convert? (bit_xor:c (bit_not @0) @1)))
678 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
679 (convert (bit_xor @0 @1))))
680
681 /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
682 (simplify
683 (bit_ior:c (bit_and:cs @0 (bit_not @2)) (bit_and:cs @1 @2))
684 (bit_xor (bit_and (bit_xor @0 @1) @2) @0))
685
686 /* Fold A - (A & B) into ~B & A. */
687 (simplify
688 (minus (convert? @0) (convert?:s (bit_and:cs @0 @1)))
689 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
690 && tree_nop_conversion_p (type, TREE_TYPE (@1)))
691 (convert (bit_and (bit_not @1) @0))))
692
693 /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)). */
694 (simplify
695 (pointer_plus (pointer_plus:s @0 @1) @3)
696 (pointer_plus @0 (plus @1 @3)))
697
698 /* Pattern match
699 tem1 = (long) ptr1;
700 tem2 = (long) ptr2;
701 tem3 = tem2 - tem1;
702 tem4 = (unsigned long) tem3;
703 tem5 = ptr1 + tem4;
704 and produce
705 tem5 = ptr2; */
706 (simplify
707 (pointer_plus @0 (convert?@2 (minus@3 (convert @1) (convert @0))))
708 /* Conditionally look through a sign-changing conversion. */
709 (if (TYPE_PRECISION (TREE_TYPE (@2)) == TYPE_PRECISION (TREE_TYPE (@3))
710 && ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@1)))
711 || (GENERIC && type == TREE_TYPE (@1))))
712 @1))
713
714 /* Pattern match
715 tem = (sizetype) ptr;
716 tem = tem & algn;
717 tem = -tem;
718 ... = ptr p+ tem;
719 and produce the simpler and easier to analyze with respect to alignment
720 ... = ptr & ~algn; */
721 (simplify
722 (pointer_plus @0 (negate (bit_and (convert @0) INTEGER_CST@1)))
723 (with { tree algn = wide_int_to_tree (TREE_TYPE (@0), wi::bit_not (@1)); }
724 (bit_and @0 { algn; })))
725
726 /* Try folding difference of addresses. */
727 (simplify
728 (minus (convert ADDR_EXPR@0) (convert @1))
729 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
730 (with { HOST_WIDE_INT diff; }
731 (if (ptr_difference_const (@0, @1, &diff))
732 { build_int_cst_type (type, diff); }))))
733 (simplify
734 (minus (convert @0) (convert ADDR_EXPR@1))
735 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
736 (with { HOST_WIDE_INT diff; }
737 (if (ptr_difference_const (@0, @1, &diff))
738 { build_int_cst_type (type, diff); }))))
739
740 /* If arg0 is derived from the address of an object or function, we may
741 be able to fold this expression using the object or function's
742 alignment. */
743 (simplify
744 (bit_and (convert? @0) INTEGER_CST@1)
745 (if (POINTER_TYPE_P (TREE_TYPE (@0))
746 && tree_nop_conversion_p (type, TREE_TYPE (@0)))
747 (with
748 {
749 unsigned int align;
750 unsigned HOST_WIDE_INT bitpos;
751 get_pointer_alignment_1 (@0, &align, &bitpos);
752 }
753 (if (wi::ltu_p (@1, align / BITS_PER_UNIT))
754 { wide_int_to_tree (type, wi::bit_and (@1, bitpos / BITS_PER_UNIT)); }))))
755
756
757 /* We can't reassociate at all for saturating types. */
758 (if (!TYPE_SATURATING (type))
759
760 /* Contract negates. */
761 /* A + (-B) -> A - B */
762 (simplify
763 (plus:c (convert1? @0) (convert2? (negate @1)))
764 /* Apply STRIP_NOPS on @0 and the negate. */
765 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
766 && tree_nop_conversion_p (type, TREE_TYPE (@1))
767 && !TYPE_OVERFLOW_SANITIZED (type))
768 (minus (convert @0) (convert @1))))
769 /* A - (-B) -> A + B */
770 (simplify
771 (minus (convert1? @0) (convert2? (negate @1)))
772 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
773 && tree_nop_conversion_p (type, TREE_TYPE (@1))
774 && !TYPE_OVERFLOW_SANITIZED (type))
775 (plus (convert @0) (convert @1))))
776 /* -(-A) -> A */
777 (simplify
778 (negate (convert? (negate @1)))
779 (if (tree_nop_conversion_p (type, TREE_TYPE (@1))
780 && !TYPE_OVERFLOW_SANITIZED (type))
781 (convert @1)))
782
783 /* We can't reassociate floating-point unless -fassociative-math
784 or fixed-point plus or minus because of saturation to +-Inf. */
785 (if ((!FLOAT_TYPE_P (type) || flag_associative_math)
786 && !FIXED_POINT_TYPE_P (type))
787
788 /* Match patterns that allow contracting a plus-minus pair
789 irrespective of overflow issues. */
790 /* (A +- B) - A -> +- B */
791 /* (A +- B) -+ B -> A */
792 /* A - (A +- B) -> -+ B */
793 /* A +- (B -+ A) -> +- B */
794 (simplify
795 (minus (plus:c @0 @1) @0)
796 @1)
797 (simplify
798 (minus (minus @0 @1) @0)
799 (negate @1))
800 (simplify
801 (plus:c (minus @0 @1) @1)
802 @0)
803 (simplify
804 (minus @0 (plus:c @0 @1))
805 (negate @1))
806 (simplify
807 (minus @0 (minus @0 @1))
808 @1)
809
810 /* (A +- CST) +- CST -> A + CST */
811 (for outer_op (plus minus)
812 (for inner_op (plus minus)
813 (simplify
814 (outer_op (inner_op @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
815 /* If the constant operation overflows we cannot do the transform
816 as we would introduce undefined overflow, for example
817 with (a - 1) + INT_MIN. */
818 (with { tree cst = fold_binary (outer_op == inner_op
819 ? PLUS_EXPR : MINUS_EXPR, type, @1, @2); }
820 (if (cst && !TREE_OVERFLOW (cst))
821 (inner_op @0 { cst; } ))))))
822
823 /* (CST - A) +- CST -> CST - A */
824 (for outer_op (plus minus)
825 (simplify
826 (outer_op (minus CONSTANT_CLASS_P@1 @0) CONSTANT_CLASS_P@2)
827 (with { tree cst = fold_binary (outer_op, type, @1, @2); }
828 (if (cst && !TREE_OVERFLOW (cst))
829 (minus { cst; } @0)))))
830
831 /* ~A + A -> -1 */
832 (simplify
833 (plus:c (bit_not @0) @0)
834 (if (!TYPE_OVERFLOW_TRAPS (type))
835 { build_all_ones_cst (type); }))
836
837 /* ~A + 1 -> -A */
838 (simplify
839 (plus (convert? (bit_not @0)) integer_each_onep)
840 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
841 (negate (convert @0))))
842
843 /* -A - 1 -> ~A */
844 (simplify
845 (minus (convert? (negate @0)) integer_each_onep)
846 (if (!TYPE_OVERFLOW_TRAPS (type)
847 && tree_nop_conversion_p (type, TREE_TYPE (@0)))
848 (bit_not (convert @0))))
849
850 /* -1 - A -> ~A */
851 (simplify
852 (minus integer_all_onesp @0)
853 (bit_not @0))
854
855 /* (T)(P + A) - (T)P -> (T) A */
856 (for add (plus pointer_plus)
857 (simplify
858 (minus (convert (add @0 @1))
859 (convert @0))
860 (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
861 /* For integer types, if A has a smaller type
862 than T the result depends on the possible
863 overflow in P + A.
864 E.g. T=size_t, A=(unsigned)429497295, P>0.
865 However, if an overflow in P + A would cause
866 undefined behavior, we can assume that there
867 is no overflow. */
868 || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
869 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
870 /* For pointer types, if the conversion of A to the
871 final type requires a sign- or zero-extension,
872 then we have to punt - it is not defined which
873 one is correct. */
874 || (POINTER_TYPE_P (TREE_TYPE (@0))
875 && TREE_CODE (@1) == INTEGER_CST
876 && tree_int_cst_sign_bit (@1) == 0))
877 (convert @1))))))
878
879
880 /* Simplifications of MIN_EXPR and MAX_EXPR. */
881
882 (for minmax (min max)
883 (simplify
884 (minmax @0 @0)
885 @0))
886 (simplify
887 (min @0 @1)
888 (if (INTEGRAL_TYPE_P (type)
889 && TYPE_MIN_VALUE (type)
890 && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
891 @1))
892 (simplify
893 (max @0 @1)
894 (if (INTEGRAL_TYPE_P (type)
895 && TYPE_MAX_VALUE (type)
896 && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
897 @1))
898
899
900 /* Simplifications of shift and rotates. */
901
902 (for rotate (lrotate rrotate)
903 (simplify
904 (rotate integer_all_onesp@0 @1)
905 @0))
906
907 /* Optimize -1 >> x for arithmetic right shifts. */
908 (simplify
909 (rshift integer_all_onesp@0 @1)
910 (if (!TYPE_UNSIGNED (type)
911 && tree_expr_nonnegative_p (@1))
912 @0))
913
914 (for shiftrotate (lrotate rrotate lshift rshift)
915 (simplify
916 (shiftrotate @0 integer_zerop)
917 (non_lvalue @0))
918 (simplify
919 (shiftrotate integer_zerop@0 @1)
920 @0)
921 /* Prefer vector1 << scalar to vector1 << vector2
922 if vector2 is uniform. */
923 (for vec (VECTOR_CST CONSTRUCTOR)
924 (simplify
925 (shiftrotate @0 vec@1)
926 (with { tree tem = uniform_vector_p (@1); }
927 (if (tem)
928 (shiftrotate @0 { tem; }))))))
929
930 /* Rewrite an LROTATE_EXPR by a constant into an
931 RROTATE_EXPR by a new constant. */
932 (simplify
933 (lrotate @0 INTEGER_CST@1)
934 (rrotate @0 { fold_binary (MINUS_EXPR, TREE_TYPE (@1),
935 build_int_cst (TREE_TYPE (@1),
936 element_precision (type)), @1); }))
937
938 /* Turn (a OP c1) OP c2 into a OP (c1+c2). */
939 (for op (lrotate rrotate rshift lshift)
940 (simplify
941 (op (op @0 INTEGER_CST@1) INTEGER_CST@2)
942 (with { unsigned int prec = element_precision (type); }
943 (if (wi::ge_p (@1, 0, TYPE_SIGN (TREE_TYPE (@1)))
944 && wi::lt_p (@1, prec, TYPE_SIGN (TREE_TYPE (@1)))
945 && wi::ge_p (@2, 0, TYPE_SIGN (TREE_TYPE (@2)))
946 && wi::lt_p (@2, prec, TYPE_SIGN (TREE_TYPE (@2))))
947 (with { unsigned int low = wi::add (@1, @2).to_uhwi (); }
948 /* Deal with a OP (c1 + c2) being undefined but (a OP c1) OP c2
949 being well defined. */
950 (if (low >= prec)
951 (if (op == LROTATE_EXPR || op == RROTATE_EXPR)
952 (op @0 { build_int_cst (TREE_TYPE (@1), low % prec); })
953 (if (TYPE_UNSIGNED (type) || op == LSHIFT_EXPR)
954 { build_zero_cst (type); }
955 (op @0 { build_int_cst (TREE_TYPE (@1), prec - 1); })))
956 (op @0 { build_int_cst (TREE_TYPE (@1), low); })))))))
957
958
959 /* ((1 << A) & 1) != 0 -> A == 0
960 ((1 << A) & 1) == 0 -> A != 0 */
961 (for cmp (ne eq)
962 icmp (eq ne)
963 (simplify
964 (cmp (bit_and (lshift integer_onep @0) integer_onep) integer_zerop)
965 (icmp @0 { build_zero_cst (TREE_TYPE (@0)); })))
966
967 /* (CST1 << A) == CST2 -> A == ctz (CST2) - ctz (CST1)
968 (CST1 << A) != CST2 -> A != ctz (CST2) - ctz (CST1)
969 if CST2 != 0. */
970 (for cmp (ne eq)
971 (simplify
972 (cmp (lshift INTEGER_CST@0 @1) INTEGER_CST@2)
973 (with { int cand = wi::ctz (@2) - wi::ctz (@0); }
974 (if (cand < 0
975 || (!integer_zerop (@2)
976 && wi::ne_p (wi::lshift (@0, cand), @2)))
977 { constant_boolean_node (cmp == NE_EXPR, type); }
978 (if (!integer_zerop (@2)
979 && wi::eq_p (wi::lshift (@0, cand), @2))
980 (cmp @1 { build_int_cst (TREE_TYPE (@1), cand); }))))))
981
982 /* Fold (X << C1) & C2 into (X << C1) & (C2 | ((1 << C1) - 1))
983 (X >> C1) & C2 into (X >> C1) & (C2 | ~((type) -1 >> C1))
984 if the new mask might be further optimized. */
985 (for shift (lshift rshift)
986 (simplify
987 (bit_and (convert?:s@4 (shift:s@5 (convert1?@3 @0) INTEGER_CST@1))
988 INTEGER_CST@2)
989 (if (tree_nop_conversion_p (TREE_TYPE (@4), TREE_TYPE (@5))
990 && TYPE_PRECISION (type) <= HOST_BITS_PER_WIDE_INT
991 && tree_fits_uhwi_p (@1)
992 && tree_to_uhwi (@1) > 0
993 && tree_to_uhwi (@1) < TYPE_PRECISION (type))
994 (with
995 {
996 unsigned int shiftc = tree_to_uhwi (@1);
997 unsigned HOST_WIDE_INT mask = TREE_INT_CST_LOW (@2);
998 unsigned HOST_WIDE_INT newmask, zerobits = 0;
999 tree shift_type = TREE_TYPE (@3);
1000 unsigned int prec;
1001
1002 if (shift == LSHIFT_EXPR)
1003 zerobits = ((((unsigned HOST_WIDE_INT) 1) << shiftc) - 1);
1004 else if (shift == RSHIFT_EXPR
1005 && (TYPE_PRECISION (shift_type)
1006 == GET_MODE_PRECISION (TYPE_MODE (shift_type))))
1007 {
1008 prec = TYPE_PRECISION (TREE_TYPE (@3));
1009 tree arg00 = @0;
1010 /* See if more bits can be proven as zero because of
1011 zero extension. */
1012 if (@3 != @0
1013 && TYPE_UNSIGNED (TREE_TYPE (@0)))
1014 {
1015 tree inner_type = TREE_TYPE (@0);
1016 if ((TYPE_PRECISION (inner_type)
1017 == GET_MODE_PRECISION (TYPE_MODE (inner_type)))
1018 && TYPE_PRECISION (inner_type) < prec)
1019 {
1020 prec = TYPE_PRECISION (inner_type);
1021 /* See if we can shorten the right shift. */
1022 if (shiftc < prec)
1023 shift_type = inner_type;
1024 /* Otherwise X >> C1 is all zeros, so we'll optimize
1025 it into (X, 0) later on by making sure zerobits
1026 is all ones. */
1027 }
1028 }
1029 zerobits = ~(unsigned HOST_WIDE_INT) 0;
1030 if (shiftc < prec)
1031 {
1032 zerobits >>= HOST_BITS_PER_WIDE_INT - shiftc;
1033 zerobits <<= prec - shiftc;
1034 }
1035 /* For arithmetic shift if sign bit could be set, zerobits
1036 can contain actually sign bits, so no transformation is
1037 possible, unless MASK masks them all away. In that
1038 case the shift needs to be converted into logical shift. */
1039 if (!TYPE_UNSIGNED (TREE_TYPE (@3))
1040 && prec == TYPE_PRECISION (TREE_TYPE (@3)))
1041 {
1042 if ((mask & zerobits) == 0)
1043 shift_type = unsigned_type_for (TREE_TYPE (@3));
1044 else
1045 zerobits = 0;
1046 }
1047 }
1048 }
1049 /* ((X << 16) & 0xff00) is (X, 0). */
1050 (if ((mask & zerobits) == mask)
1051 { build_int_cst (type, 0); }
1052 (with { newmask = mask | zerobits; }
1053 (if (newmask != mask && (newmask & (newmask + 1)) == 0)
1054 (with
1055 {
1056 /* Only do the transformation if NEWMASK is some integer
1057 mode's mask. */
1058 for (prec = BITS_PER_UNIT;
1059 prec < HOST_BITS_PER_WIDE_INT; prec <<= 1)
1060 if (newmask == (((unsigned HOST_WIDE_INT) 1) << prec) - 1)
1061 break;
1062 }
1063 (if (prec < HOST_BITS_PER_WIDE_INT
1064 || newmask == ~(unsigned HOST_WIDE_INT) 0)
1065 (with
1066 { tree newmaskt = build_int_cst_type (TREE_TYPE (@2), newmask); }
1067 (if (!tree_int_cst_equal (newmaskt, @2))
1068 (if (shift_type != TREE_TYPE (@3))
1069 (bit_and (convert (shift:shift_type (convert @3) @1)) { newmaskt; })
1070 (bit_and @4 { newmaskt; })))))))))))))
1071
1072 /* Fold (X & C2) << C1 into (X << C1) & (C2 << C1)
1073 (X & C2) >> C1 into (X >> C1) & (C2 >> C1). */
1074 (for shift (lshift rshift)
1075 (simplify
1076 (shift (convert?:s (bit_and:s @0 INTEGER_CST@2)) INTEGER_CST@1)
1077 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
1078 (with { tree mask = int_const_binop (shift, fold_convert (type, @2), @1); }
1079 (bit_and (shift (convert @0) @1) { mask; })))))
1080
1081
1082 /* Simplifications of conversions. */
1083
1084 /* Basic strip-useless-type-conversions / strip_nops. */
1085 (for cvt (convert view_convert float fix_trunc)
1086 (simplify
1087 (cvt @0)
1088 (if ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@0)))
1089 || (GENERIC && type == TREE_TYPE (@0)))
1090 @0)))
1091
1092 /* Contract view-conversions. */
1093 (simplify
1094 (view_convert (view_convert @0))
1095 (view_convert @0))
1096
1097 /* For integral conversions with the same precision or pointer
1098 conversions use a NOP_EXPR instead. */
1099 (simplify
1100 (view_convert @0)
1101 (if ((INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
1102 && (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
1103 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (@0)))
1104 (convert @0)))
1105
1106 /* Strip inner integral conversions that do not change precision or size. */
1107 (simplify
1108 (view_convert (convert@0 @1))
1109 (if ((INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
1110 && (INTEGRAL_TYPE_P (TREE_TYPE (@1)) || POINTER_TYPE_P (TREE_TYPE (@1)))
1111 && (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1)))
1112 && (TYPE_SIZE (TREE_TYPE (@0)) == TYPE_SIZE (TREE_TYPE (@1))))
1113 (view_convert @1)))
1114
1115 /* Re-association barriers around constants and other re-association
1116 barriers can be removed. */
1117 (simplify
1118 (paren CONSTANT_CLASS_P@0)
1119 @0)
1120 (simplify
1121 (paren (paren@1 @0))
1122 @1)
1123
1124 /* Handle cases of two conversions in a row. */
1125 (for ocvt (convert float fix_trunc)
1126 (for icvt (convert float)
1127 (simplify
1128 (ocvt (icvt@1 @0))
1129 (with
1130 {
1131 tree inside_type = TREE_TYPE (@0);
1132 tree inter_type = TREE_TYPE (@1);
1133 int inside_int = INTEGRAL_TYPE_P (inside_type);
1134 int inside_ptr = POINTER_TYPE_P (inside_type);
1135 int inside_float = FLOAT_TYPE_P (inside_type);
1136 int inside_vec = VECTOR_TYPE_P (inside_type);
1137 unsigned int inside_prec = TYPE_PRECISION (inside_type);
1138 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
1139 int inter_int = INTEGRAL_TYPE_P (inter_type);
1140 int inter_ptr = POINTER_TYPE_P (inter_type);
1141 int inter_float = FLOAT_TYPE_P (inter_type);
1142 int inter_vec = VECTOR_TYPE_P (inter_type);
1143 unsigned int inter_prec = TYPE_PRECISION (inter_type);
1144 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
1145 int final_int = INTEGRAL_TYPE_P (type);
1146 int final_ptr = POINTER_TYPE_P (type);
1147 int final_float = FLOAT_TYPE_P (type);
1148 int final_vec = VECTOR_TYPE_P (type);
1149 unsigned int final_prec = TYPE_PRECISION (type);
1150 int final_unsignedp = TYPE_UNSIGNED (type);
1151 }
1152 (switch
1153 /* In addition to the cases of two conversions in a row
1154 handled below, if we are converting something to its own
1155 type via an object of identical or wider precision, neither
1156 conversion is needed. */
1157 (if (((GIMPLE && useless_type_conversion_p (type, inside_type))
1158 || (GENERIC
1159 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (inside_type)))
1160 && (((inter_int || inter_ptr) && final_int)
1161 || (inter_float && final_float))
1162 && inter_prec >= final_prec)
1163 (ocvt @0))
1164
1165 /* Likewise, if the intermediate and initial types are either both
1166 float or both integer, we don't need the middle conversion if the
1167 former is wider than the latter and doesn't change the signedness
1168 (for integers). Avoid this if the final type is a pointer since
1169 then we sometimes need the middle conversion. Likewise if the
1170 final type has a precision not equal to the size of its mode. */
1171 (if (((inter_int && inside_int) || (inter_float && inside_float))
1172 && (final_int || final_float)
1173 && inter_prec >= inside_prec
1174 && (inter_float || inter_unsignedp == inside_unsignedp)
1175 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
1176 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
1177 (ocvt @0))
1178
1179 /* If we have a sign-extension of a zero-extended value, we can
1180 replace that by a single zero-extension. Likewise if the
1181 final conversion does not change precision we can drop the
1182 intermediate conversion. */
1183 (if (inside_int && inter_int && final_int
1184 && ((inside_prec < inter_prec && inter_prec < final_prec
1185 && inside_unsignedp && !inter_unsignedp)
1186 || final_prec == inter_prec))
1187 (ocvt @0))
1188
1189 /* Two conversions in a row are not needed unless:
1190 - some conversion is floating-point (overstrict for now), or
1191 - some conversion is a vector (overstrict for now), or
1192 - the intermediate type is narrower than both initial and
1193 final, or
1194 - the intermediate type and innermost type differ in signedness,
1195 and the outermost type is wider than the intermediate, or
1196 - the initial type is a pointer type and the precisions of the
1197 intermediate and final types differ, or
1198 - the final type is a pointer type and the precisions of the
1199 initial and intermediate types differ. */
1200 (if (! inside_float && ! inter_float && ! final_float
1201 && ! inside_vec && ! inter_vec && ! final_vec
1202 && (inter_prec >= inside_prec || inter_prec >= final_prec)
1203 && ! (inside_int && inter_int
1204 && inter_unsignedp != inside_unsignedp
1205 && inter_prec < final_prec)
1206 && ((inter_unsignedp && inter_prec > inside_prec)
1207 == (final_unsignedp && final_prec > inter_prec))
1208 && ! (inside_ptr && inter_prec != final_prec)
1209 && ! (final_ptr && inside_prec != inter_prec)
1210 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
1211 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
1212 (ocvt @0))
1213
1214 /* A truncation to an unsigned type (a zero-extension) should be
1215 canonicalized as bitwise and of a mask. */
1216 (if (final_int && inter_int && inside_int
1217 && final_prec == inside_prec
1218 && final_prec > inter_prec
1219 && inter_unsignedp)
1220 (convert (bit_and @0 { wide_int_to_tree
1221 (inside_type,
1222 wi::mask (inter_prec, false,
1223 TYPE_PRECISION (inside_type))); })))
1224
1225 /* If we are converting an integer to a floating-point that can
1226 represent it exactly and back to an integer, we can skip the
1227 floating-point conversion. */
1228 (if (GIMPLE /* PR66211 */
1229 && inside_int && inter_float && final_int &&
1230 (unsigned) significand_size (TYPE_MODE (inter_type))
1231 >= inside_prec - !inside_unsignedp)
1232 (convert @0)))))))
1233
1234 /* If we have a narrowing conversion to an integral type that is fed by a
1235 BIT_AND_EXPR, we might be able to remove the BIT_AND_EXPR if it merely
1236 masks off bits outside the final type (and nothing else). */
1237 (simplify
1238 (convert (bit_and @0 INTEGER_CST@1))
1239 (if (INTEGRAL_TYPE_P (type)
1240 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
1241 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (@0))
1242 && operand_equal_p (@1, build_low_bits_mask (TREE_TYPE (@1),
1243 TYPE_PRECISION (type)), 0))
1244 (convert @0)))
1245
1246
1247 /* (X /[ex] A) * A -> X. */
1248 (simplify
1249 (mult (convert? (exact_div @0 @1)) @1)
1250 /* Look through a sign-changing conversion. */
1251 (convert @0))
1252
1253 /* Canonicalization of binary operations. */
1254
1255 /* Convert X + -C into X - C. */
1256 (simplify
1257 (plus @0 REAL_CST@1)
1258 (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
1259 (with { tree tem = fold_unary (NEGATE_EXPR, type, @1); }
1260 (if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
1261 (minus @0 { tem; })))))
1262
1263 /* Convert x+x into x*2.0. */
1264 (simplify
1265 (plus @0 @0)
1266 (if (SCALAR_FLOAT_TYPE_P (type))
1267 (mult @0 { build_real (type, dconst2); })))
1268
1269 (simplify
1270 (minus integer_zerop @1)
1271 (negate @1))
1272
1273 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
1274 ARG0 is zero and X + ARG0 reduces to X, since that would mean
1275 (-ARG1 + ARG0) reduces to -ARG1. */
1276 (simplify
1277 (minus real_zerop@0 @1)
1278 (if (fold_real_zero_addition_p (type, @0, 0))
1279 (negate @1)))
1280
1281 /* Transform x * -1 into -x. */
1282 (simplify
1283 (mult @0 integer_minus_onep)
1284 (negate @0))
1285
1286 /* COMPLEX_EXPR and REALPART/IMAGPART_EXPR cancellations. */
1287 (simplify
1288 (complex (realpart @0) (imagpart @0))
1289 @0)
1290 (simplify
1291 (realpart (complex @0 @1))
1292 @0)
1293 (simplify
1294 (imagpart (complex @0 @1))
1295 @1)
1296
1297
1298 /* BSWAP simplifications, transforms checked by gcc.dg/builtin-bswap-8.c. */
1299 (for bswap (BUILT_IN_BSWAP16 BUILT_IN_BSWAP32 BUILT_IN_BSWAP64)
1300 (simplify
1301 (bswap (bswap @0))
1302 @0)
1303 (simplify
1304 (bswap (bit_not (bswap @0)))
1305 (bit_not @0))
1306 (for bitop (bit_xor bit_ior bit_and)
1307 (simplify
1308 (bswap (bitop:c (bswap @0) @1))
1309 (bitop @0 (bswap @1)))))
1310
1311
1312 /* Combine COND_EXPRs and VEC_COND_EXPRs. */
1313
1314 /* Simplify constant conditions.
1315 Only optimize constant conditions when the selected branch
1316 has the same type as the COND_EXPR. This avoids optimizing
1317 away "c ? x : throw", where the throw has a void type.
1318 Note that we cannot throw away the fold-const.c variant nor
1319 this one as we depend on doing this transform before possibly
1320 A ? B : B -> B triggers and the fold-const.c one can optimize
1321 0 ? A : B to B even if A has side-effects. Something
1322 genmatch cannot handle. */
1323 (simplify
1324 (cond INTEGER_CST@0 @1 @2)
1325 (if (integer_zerop (@0))
1326 (if (!VOID_TYPE_P (TREE_TYPE (@2)) || VOID_TYPE_P (type))
1327 @2)
1328 (if (!VOID_TYPE_P (TREE_TYPE (@1)) || VOID_TYPE_P (type))
1329 @1)))
1330 (simplify
1331 (vec_cond VECTOR_CST@0 @1 @2)
1332 (if (integer_all_onesp (@0))
1333 @1
1334 (if (integer_zerop (@0))
1335 @2)))
1336
1337 (for cnd (cond vec_cond)
1338 /* A ? B : (A ? X : C) -> A ? B : C. */
1339 (simplify
1340 (cnd @0 (cnd @0 @1 @2) @3)
1341 (cnd @0 @1 @3))
1342 (simplify
1343 (cnd @0 @1 (cnd @0 @2 @3))
1344 (cnd @0 @1 @3))
1345
1346 /* A ? B : B -> B. */
1347 (simplify
1348 (cnd @0 @1 @1)
1349 @1)
1350
1351 /* !A ? B : C -> A ? C : B. */
1352 (simplify
1353 (cnd (logical_inverted_value truth_valued_p@0) @1 @2)
1354 (cnd @0 @2 @1)))
1355
1356 /* A + (B vcmp C ? 1 : 0) -> A - (B vcmp C), since vector comparisons
1357 return all-1 or all-0 results. */
1358 /* ??? We could instead convert all instances of the vec_cond to negate,
1359 but that isn't necessarily a win on its own. */
1360 (simplify
1361 (plus:c @3 (view_convert? (vec_cond @0 integer_each_onep@1 integer_zerop@2)))
1362 (if (VECTOR_TYPE_P (type)
1363 && TYPE_VECTOR_SUBPARTS (type) == TYPE_VECTOR_SUBPARTS (TREE_TYPE (@0))
1364 && (TYPE_MODE (TREE_TYPE (type))
1365 == TYPE_MODE (TREE_TYPE (TREE_TYPE (@0)))))
1366 (minus @3 (view_convert @0))))
1367
1368 /* ... likewise A - (B vcmp C ? 1 : 0) -> A + (B vcmp C). */
1369 (simplify
1370 (minus @3 (view_convert? (vec_cond @0 integer_each_onep@1 integer_zerop@2)))
1371 (if (VECTOR_TYPE_P (type)
1372 && TYPE_VECTOR_SUBPARTS (type) == TYPE_VECTOR_SUBPARTS (TREE_TYPE (@0))
1373 && (TYPE_MODE (TREE_TYPE (type))
1374 == TYPE_MODE (TREE_TYPE (TREE_TYPE (@0)))))
1375 (plus @3 (view_convert @0))))
1376
1377
1378 /* Simplifications of comparisons. */
1379
1380 /* See if we can reduce the magnitude of a constant involved in a
1381 comparison by changing the comparison code. This is a canonicalization
1382 formerly done by maybe_canonicalize_comparison_1. */
1383 (for cmp (le gt)
1384 acmp (lt ge)
1385 (simplify
1386 (cmp @0 INTEGER_CST@1)
1387 (if (tree_int_cst_sgn (@1) == -1)
1388 (acmp @0 { wide_int_to_tree (TREE_TYPE (@1), wi::add (@1, 1)); }))))
1389 (for cmp (ge lt)
1390 acmp (gt le)
1391 (simplify
1392 (cmp @0 INTEGER_CST@1)
1393 (if (tree_int_cst_sgn (@1) == 1)
1394 (acmp @0 { wide_int_to_tree (TREE_TYPE (@1), wi::sub (@1, 1)); }))))
1395
1396
1397 /* We can simplify a logical negation of a comparison to the
1398 inverted comparison. As we cannot compute an expression
1399 operator using invert_tree_comparison we have to simulate
1400 that with expression code iteration. */
1401 (for cmp (tcc_comparison)
1402 icmp (inverted_tcc_comparison)
1403 ncmp (inverted_tcc_comparison_with_nans)
1404 /* Ideally we'd like to combine the following two patterns
1405 and handle some more cases by using
1406 (logical_inverted_value (cmp @0 @1))
1407 here but for that genmatch would need to "inline" that.
1408 For now implement what forward_propagate_comparison did. */
1409 (simplify
1410 (bit_not (cmp @0 @1))
1411 (if (VECTOR_TYPE_P (type)
1412 || (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1))
1413 /* Comparison inversion may be impossible for trapping math,
1414 invert_tree_comparison will tell us. But we can't use
1415 a computed operator in the replacement tree thus we have
1416 to play the trick below. */
1417 (with { enum tree_code ic = invert_tree_comparison
1418 (cmp, HONOR_NANS (@0)); }
1419 (if (ic == icmp)
1420 (icmp @0 @1)
1421 (if (ic == ncmp)
1422 (ncmp @0 @1))))))
1423 (simplify
1424 (bit_xor (cmp @0 @1) integer_truep)
1425 (with { enum tree_code ic = invert_tree_comparison
1426 (cmp, HONOR_NANS (@0)); }
1427 (if (ic == icmp)
1428 (icmp @0 @1)
1429 (if (ic == ncmp)
1430 (ncmp @0 @1))))))
1431
1432 /* Transform comparisons of the form X - Y CMP 0 to X CMP Y.
1433 ??? The transformation is valid for the other operators if overflow
1434 is undefined for the type, but performing it here badly interacts
1435 with the transformation in fold_cond_expr_with_comparison which
1436 attempts to synthetize ABS_EXPR. */
1437 (for cmp (eq ne)
1438 (simplify
1439 (cmp (minus@2 @0 @1) integer_zerop)
1440 (if (single_use (@2))
1441 (cmp @0 @1))))
1442
1443 /* Transform comparisons of the form X * C1 CMP 0 to X CMP 0 in the
1444 signed arithmetic case. That form is created by the compiler
1445 often enough for folding it to be of value. One example is in
1446 computing loop trip counts after Operator Strength Reduction. */
1447 (for cmp (simple_comparison)
1448 scmp (swapped_simple_comparison)
1449 (simplify
1450 (cmp (mult @0 INTEGER_CST@1) integer_zerop@2)
1451 /* Handle unfolded multiplication by zero. */
1452 (if (integer_zerop (@1))
1453 (cmp @1 @2)
1454 (if (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
1455 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
1456 /* If @1 is negative we swap the sense of the comparison. */
1457 (if (tree_int_cst_sgn (@1) < 0)
1458 (scmp @0 @2)
1459 (cmp @0 @2))))))
1460
1461 /* Simplify comparison of something with itself. For IEEE
1462 floating-point, we can only do some of these simplifications. */
1463 (simplify
1464 (eq @0 @0)
1465 (if (! FLOAT_TYPE_P (TREE_TYPE (@0))
1466 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (@0))))
1467 { constant_boolean_node (true, type); }))
1468 (for cmp (ge le)
1469 (simplify
1470 (cmp @0 @0)
1471 (eq @0 @0)))
1472 (for cmp (ne gt lt)
1473 (simplify
1474 (cmp @0 @0)
1475 (if (cmp != NE_EXPR
1476 || ! FLOAT_TYPE_P (TREE_TYPE (@0))
1477 || ! HONOR_NANS (TYPE_MODE (TREE_TYPE (@0))))
1478 { constant_boolean_node (false, type); })))
1479 (for cmp (unle unge uneq)
1480 (simplify
1481 (cmp @0 @0)
1482 { constant_boolean_node (true, type); }))
1483 (simplify
1484 (ltgt @0 @0)
1485 (if (!flag_trapping_math)
1486 { constant_boolean_node (false, type); }))
1487
1488 /* Fold ~X op ~Y as Y op X. */
1489 (for cmp (simple_comparison)
1490 (simplify
1491 (cmp (bit_not @0) (bit_not @1))
1492 (cmp @1 @0)))
1493
1494 /* Fold ~X op C as X op' ~C, where op' is the swapped comparison. */
1495 (for cmp (simple_comparison)
1496 scmp (swapped_simple_comparison)
1497 (simplify
1498 (cmp (bit_not @0) CONSTANT_CLASS_P@1)
1499 (if (TREE_CODE (@1) == INTEGER_CST || TREE_CODE (@1) == VECTOR_CST)
1500 (scmp @0 (bit_not @1)))))
1501
1502 (for cmp (simple_comparison)
1503 /* Fold (double)float1 CMP (double)float2 into float1 CMP float2. */
1504 (simplify
1505 (cmp (convert@2 @0) (convert? @1))
1506 (if (FLOAT_TYPE_P (TREE_TYPE (@0))
1507 && (DECIMAL_FLOAT_TYPE_P (TREE_TYPE (@2))
1508 == DECIMAL_FLOAT_TYPE_P (TREE_TYPE (@0)))
1509 && (DECIMAL_FLOAT_TYPE_P (TREE_TYPE (@2))
1510 == DECIMAL_FLOAT_TYPE_P (TREE_TYPE (@1))))
1511 (with
1512 {
1513 tree type1 = TREE_TYPE (@1);
1514 if (TREE_CODE (@1) == REAL_CST && !DECIMAL_FLOAT_TYPE_P (type1))
1515 {
1516 REAL_VALUE_TYPE orig = TREE_REAL_CST (@1);
1517 if (TYPE_PRECISION (type1) > TYPE_PRECISION (float_type_node)
1518 && exact_real_truncate (TYPE_MODE (float_type_node), &orig))
1519 type1 = float_type_node;
1520 if (TYPE_PRECISION (type1) > TYPE_PRECISION (double_type_node)
1521 && exact_real_truncate (TYPE_MODE (double_type_node), &orig))
1522 type1 = double_type_node;
1523 }
1524 tree newtype
1525 = (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (type1)
1526 ? TREE_TYPE (@0) : type1);
1527 }
1528 (if (TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (newtype))
1529 (cmp (convert:newtype @0) (convert:newtype @1))))))
1530
1531 (simplify
1532 (cmp @0 REAL_CST@1)
1533 /* IEEE doesn't distinguish +0 and -0 in comparisons. */
1534 (switch
1535 /* a CMP (-0) -> a CMP 0 */
1536 (if (REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (@1)))
1537 (cmp @0 { build_real (TREE_TYPE (@1), dconst0); }))
1538 /* x != NaN is always true, other ops are always false. */
1539 (if (REAL_VALUE_ISNAN (TREE_REAL_CST (@1))
1540 && ! HONOR_SNANS (@1))
1541 { constant_boolean_node (cmp == NE_EXPR, type); })
1542 /* Fold comparisons against infinity. */
1543 (if (REAL_VALUE_ISINF (TREE_REAL_CST (@1))
1544 && MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (@1))))
1545 (with
1546 {
1547 REAL_VALUE_TYPE max;
1548 enum tree_code code = cmp;
1549 bool neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1));
1550 if (neg)
1551 code = swap_tree_comparison (code);
1552 }
1553 (switch
1554 /* x > +Inf is always false, if with ignore sNANs. */
1555 (if (code == GT_EXPR
1556 && ! HONOR_SNANS (@0))
1557 { constant_boolean_node (false, type); })
1558 (if (code == LE_EXPR)
1559 /* x <= +Inf is always true, if we don't case about NaNs. */
1560 (if (! HONOR_NANS (@0))
1561 { constant_boolean_node (true, type); }
1562 /* x <= +Inf is the same as x == x, i.e. isfinite(x). */
1563 (eq @0 @0)))
1564 /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */
1565 (if (code == EQ_EXPR || code == GE_EXPR)
1566 (with { real_maxval (&max, neg, TYPE_MODE (TREE_TYPE (@0))); }
1567 (if (neg)
1568 (lt @0 { build_real (TREE_TYPE (@0), max); })
1569 (gt @0 { build_real (TREE_TYPE (@0), max); }))))
1570 /* x < +Inf is always equal to x <= DBL_MAX. */
1571 (if (code == LT_EXPR)
1572 (with { real_maxval (&max, neg, TYPE_MODE (TREE_TYPE (@0))); }
1573 (if (neg)
1574 (ge @0 { build_real (TREE_TYPE (@0), max); })
1575 (le @0 { build_real (TREE_TYPE (@0), max); }))))
1576 /* x != +Inf is always equal to !(x > DBL_MAX). */
1577 (if (code == NE_EXPR)
1578 (with { real_maxval (&max, neg, TYPE_MODE (TREE_TYPE (@0))); }
1579 (if (! HONOR_NANS (@0))
1580 (if (neg)
1581 (ge @0 { build_real (TREE_TYPE (@0), max); })
1582 (le @0 { build_real (TREE_TYPE (@0), max); }))
1583 (if (neg)
1584 (bit_xor (lt @0 { build_real (TREE_TYPE (@0), max); })
1585 { build_one_cst (type); })
1586 (bit_xor (gt @0 { build_real (TREE_TYPE (@0), max); })
1587 { build_one_cst (type); }))))))))))
1588
1589 /* If this is a comparison of a real constant with a PLUS_EXPR
1590 or a MINUS_EXPR of a real constant, we can convert it into a
1591 comparison with a revised real constant as long as no overflow
1592 occurs when unsafe_math_optimizations are enabled. */
1593 (if (flag_unsafe_math_optimizations)
1594 (for op (plus minus)
1595 (simplify
1596 (cmp (op @0 REAL_CST@1) REAL_CST@2)
1597 (with
1598 {
1599 tree tem = const_binop (op == PLUS_EXPR ? MINUS_EXPR : PLUS_EXPR,
1600 TREE_TYPE (@1), @2, @1);
1601 }
1602 (if (tem && !TREE_OVERFLOW (tem))
1603 (cmp @0 { tem; }))))))
1604
1605 /* Likewise, we can simplify a comparison of a real constant with
1606 a MINUS_EXPR whose first operand is also a real constant, i.e.
1607 (c1 - x) < c2 becomes x > c1-c2. Reordering is allowed on
1608 floating-point types only if -fassociative-math is set. */
1609 (if (flag_associative_math)
1610 (simplify
1611 (cmp (minus REAL_CST@0 @1) REAL_CST@2)
1612 (with { tree tem = const_binop (MINUS_EXPR, TREE_TYPE (@1), @0, @2); }
1613 (if (tem && !TREE_OVERFLOW (tem))
1614 (cmp { tem; } @1)))))
1615
1616 /* Fold comparisons against built-in math functions. */
1617 (if (flag_unsafe_math_optimizations
1618 && ! flag_errno_math)
1619 (for sq (SQRT)
1620 (simplify
1621 (cmp (sq @0) REAL_CST@1)
1622 (switch
1623 (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
1624 (switch
1625 /* sqrt(x) < y is always false, if y is negative. */
1626 (if (cmp == EQ_EXPR || cmp == LT_EXPR || cmp == LE_EXPR)
1627 { constant_boolean_node (false, type); })
1628 /* sqrt(x) > y is always true, if y is negative and we
1629 don't care about NaNs, i.e. negative values of x. */
1630 (if (cmp == NE_EXPR || !HONOR_NANS (@0))
1631 { constant_boolean_node (true, type); })
1632 /* sqrt(x) > y is the same as x >= 0, if y is negative. */
1633 (ge @0 { build_real (TREE_TYPE (@0), dconst0); })))
1634 (if (cmp == GT_EXPR || cmp == GE_EXPR)
1635 (with
1636 {
1637 REAL_VALUE_TYPE c2;
1638 REAL_ARITHMETIC (c2, MULT_EXPR,
1639 TREE_REAL_CST (@1), TREE_REAL_CST (@1));
1640 real_convert (&c2, TYPE_MODE (TREE_TYPE (@0)), &c2);
1641 }
1642 (if (REAL_VALUE_ISINF (c2))
1643 /* sqrt(x) > y is x == +Inf, when y is very large. */
1644 (if (HONOR_INFINITIES (@0))
1645 (eq @0 { build_real (TREE_TYPE (@0), c2); })
1646 { constant_boolean_node (false, type); })
1647 /* sqrt(x) > c is the same as x > c*c. */
1648 (cmp @0 { build_real (TREE_TYPE (@0), c2); }))))
1649 (if (cmp == LT_EXPR || cmp == LE_EXPR)
1650 (with
1651 {
1652 REAL_VALUE_TYPE c2;
1653 REAL_ARITHMETIC (c2, MULT_EXPR,
1654 TREE_REAL_CST (@1), TREE_REAL_CST (@1));
1655 real_convert (&c2, TYPE_MODE (TREE_TYPE (@0)), &c2);
1656 }
1657 (if (REAL_VALUE_ISINF (c2))
1658 (switch
1659 /* sqrt(x) < y is always true, when y is a very large
1660 value and we don't care about NaNs or Infinities. */
1661 (if (! HONOR_NANS (@0) && ! HONOR_INFINITIES (@0))
1662 { constant_boolean_node (true, type); })
1663 /* sqrt(x) < y is x != +Inf when y is very large and we
1664 don't care about NaNs. */
1665 (if (! HONOR_NANS (@0))
1666 (ne @0 { build_real (TREE_TYPE (@0), c2); }))
1667 /* sqrt(x) < y is x >= 0 when y is very large and we
1668 don't care about Infinities. */
1669 (if (! HONOR_INFINITIES (@0))
1670 (ge @0 { build_real (TREE_TYPE (@0), dconst0); }))
1671 /* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
1672 (if (GENERIC)
1673 (truth_andif
1674 (ge @0 { build_real (TREE_TYPE (@0), dconst0); })
1675 (ne @0 { build_real (TREE_TYPE (@0), c2); }))))
1676 /* sqrt(x) < c is the same as x < c*c, if we ignore NaNs. */
1677 (if (! HONOR_NANS (@0))
1678 (cmp @0 { build_real (TREE_TYPE (@0), c2); })
1679 /* sqrt(x) < c is the same as x >= 0 && x < c*c. */
1680 (if (GENERIC)
1681 (truth_andif
1682 (ge @0 { build_real (TREE_TYPE (@0), dconst0); })
1683 (cmp @0 { build_real (TREE_TYPE (@0), c2); }))))))))))))
1684
1685 /* Unordered tests if either argument is a NaN. */
1686 (simplify
1687 (bit_ior (unordered @0 @0) (unordered @1 @1))
1688 (if (types_match (@0, @1))
1689 (unordered @0 @1)))
1690 (simplify
1691 (bit_and (ordered @0 @0) (ordered @1 @1))
1692 (if (types_match (@0, @1))
1693 (ordered @0 @1)))
1694 (simplify
1695 (bit_ior:c (unordered @0 @0) (unordered:c@2 @0 @1))
1696 @2)
1697 (simplify
1698 (bit_and:c (ordered @0 @0) (ordered:c@2 @0 @1))
1699 @2)
1700
1701 /* -A CMP -B -> B CMP A. */
1702 (for cmp (tcc_comparison)
1703 scmp (swapped_tcc_comparison)
1704 (simplify
1705 (cmp (negate @0) (negate @1))
1706 (if (FLOAT_TYPE_P (TREE_TYPE (@0))
1707 || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
1708 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
1709 (scmp @0 @1)))
1710 (simplify
1711 (cmp (negate @0) CONSTANT_CLASS_P@1)
1712 (if (FLOAT_TYPE_P (TREE_TYPE (@0))
1713 || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
1714 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
1715 (with { tree tem = fold_unary (NEGATE_EXPR, TREE_TYPE (@0), @1); }
1716 (if (tem && !TREE_OVERFLOW (tem))
1717 (scmp @0 { tem; }))))))
1718
1719 /* From fold_sign_changed_comparison and fold_widened_comparison. */
1720 (for cmp (simple_comparison)
1721 (simplify
1722 (cmp (convert@0 @00) (convert?@1 @10))
1723 (if (TREE_CODE (TREE_TYPE (@0)) == INTEGER_TYPE
1724 /* Disable this optimization if we're casting a function pointer
1725 type on targets that require function pointer canonicalization. */
1726 && !(targetm.have_canonicalize_funcptr_for_compare ()
1727 && TREE_CODE (TREE_TYPE (@00)) == POINTER_TYPE
1728 && TREE_CODE (TREE_TYPE (TREE_TYPE (@00))) == FUNCTION_TYPE)
1729 && single_use (@0))
1730 (if (TYPE_PRECISION (TREE_TYPE (@00)) == TYPE_PRECISION (TREE_TYPE (@0))
1731 && (TREE_CODE (@10) == INTEGER_CST
1732 || (@1 != @10 && types_match (TREE_TYPE (@10), TREE_TYPE (@00))))
1733 && (TYPE_UNSIGNED (TREE_TYPE (@00)) == TYPE_UNSIGNED (TREE_TYPE (@0))
1734 || cmp == NE_EXPR
1735 || cmp == EQ_EXPR)
1736 && (POINTER_TYPE_P (TREE_TYPE (@00)) == POINTER_TYPE_P (TREE_TYPE (@0))))
1737 /* ??? The special-casing of INTEGER_CST conversion was in the original
1738 code and here to avoid a spurious overflow flag on the resulting
1739 constant which fold_convert produces. */
1740 (if (TREE_CODE (@1) == INTEGER_CST)
1741 (cmp @00 { force_fit_type (TREE_TYPE (@00), wi::to_widest (@1), 0,
1742 TREE_OVERFLOW (@1)); })
1743 (cmp @00 (convert @1)))
1744
1745 (if (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (TREE_TYPE (@00)))
1746 /* If possible, express the comparison in the shorter mode. */
1747 (if ((cmp == EQ_EXPR || cmp == NE_EXPR
1748 || TYPE_UNSIGNED (TREE_TYPE (@0)) == TYPE_UNSIGNED (TREE_TYPE (@00)))
1749 && (types_match (TREE_TYPE (@10), TREE_TYPE (@00))
1750 || ((TYPE_PRECISION (TREE_TYPE (@00))
1751 >= TYPE_PRECISION (TREE_TYPE (@10)))
1752 && (TYPE_UNSIGNED (TREE_TYPE (@00))
1753 == TYPE_UNSIGNED (TREE_TYPE (@10))))
1754 || (TREE_CODE (@10) == INTEGER_CST
1755 && (TREE_CODE (TREE_TYPE (@00)) == INTEGER_TYPE
1756 || TREE_CODE (TREE_TYPE (@00)) == BOOLEAN_TYPE)
1757 && int_fits_type_p (@10, TREE_TYPE (@00)))))
1758 (cmp @00 (convert @10))
1759 (if (TREE_CODE (@10) == INTEGER_CST
1760 && TREE_CODE (TREE_TYPE (@00)) == INTEGER_TYPE
1761 && !int_fits_type_p (@10, TREE_TYPE (@00)))
1762 (with
1763 {
1764 tree min = lower_bound_in_type (TREE_TYPE (@10), TREE_TYPE (@00));
1765 tree max = upper_bound_in_type (TREE_TYPE (@10), TREE_TYPE (@00));
1766 bool above = integer_nonzerop (const_binop (LT_EXPR, type, max, @10));
1767 bool below = integer_nonzerop (const_binop (LT_EXPR, type, @10, min));
1768 }
1769 (if (above || below)
1770 (if (cmp == EQ_EXPR || cmp == NE_EXPR)
1771 { constant_boolean_node (cmp == EQ_EXPR ? false : true, type); }
1772 (if (cmp == LT_EXPR || cmp == LE_EXPR)
1773 { constant_boolean_node (above ? true : false, type); }
1774 (if (cmp == GT_EXPR || cmp == GE_EXPR)
1775 { constant_boolean_node (above ? false : true, type); }))))))))))))
1776
1777 (for cmp (eq ne)
1778 /* A local variable can never be pointed to by
1779 the default SSA name of an incoming parameter.
1780 SSA names are canonicalized to 2nd place. */
1781 (simplify
1782 (cmp addr@0 SSA_NAME@1)
1783 (if (SSA_NAME_IS_DEFAULT_DEF (@1)
1784 && TREE_CODE (SSA_NAME_VAR (@1)) == PARM_DECL)
1785 (with { tree base = get_base_address (TREE_OPERAND (@0, 0)); }
1786 (if (TREE_CODE (base) == VAR_DECL
1787 && auto_var_in_fn_p (base, current_function_decl))
1788 (if (cmp == NE_EXPR)
1789 { constant_boolean_node (true, type); }
1790 { constant_boolean_node (false, type); }))))))
1791
1792 /* Equality compare simplifications from fold_binary */
1793 (for cmp (eq ne)
1794
1795 /* If we have (A | C) == D where C & ~D != 0, convert this into 0.
1796 Similarly for NE_EXPR. */
1797 (simplify
1798 (cmp (convert?@3 (bit_ior @0 INTEGER_CST@1)) INTEGER_CST@2)
1799 (if (tree_nop_conversion_p (TREE_TYPE (@3), TREE_TYPE (@0))
1800 && wi::bit_and_not (@1, @2) != 0)
1801 { constant_boolean_node (cmp == NE_EXPR, type); }))
1802
1803 /* (X ^ Y) == 0 becomes X == Y, and (X ^ Y) != 0 becomes X != Y. */
1804 (simplify
1805 (cmp (bit_xor @0 @1) integer_zerop)
1806 (cmp @0 @1))
1807
1808 /* (X ^ Y) == Y becomes X == 0.
1809 Likewise (X ^ Y) == X becomes Y == 0. */
1810 (simplify
1811 (cmp:c (bit_xor:c @0 @1) @0)
1812 (cmp @1 { build_zero_cst (TREE_TYPE (@1)); }))
1813
1814 /* (X ^ C1) op C2 can be rewritten as X op (C1 ^ C2). */
1815 (simplify
1816 (cmp (convert?@3 (bit_xor @0 INTEGER_CST@1)) INTEGER_CST@2)
1817 (if (tree_nop_conversion_p (TREE_TYPE (@3), TREE_TYPE (@0)))
1818 (cmp @0 (bit_xor @1 (convert @2)))))
1819
1820 (simplify
1821 (cmp (convert? addr@0) integer_zerop)
1822 (if (tree_single_nonzero_warnv_p (@0, NULL))
1823 { constant_boolean_node (cmp == NE_EXPR, type); })))
1824
1825 /* When the addresses are not directly of decls compare base and offset.
1826 This implements some remaining parts of fold_comparison address
1827 comparisons but still no complete part of it. Still it is good
1828 enough to make fold_stmt not regress when not dispatching to fold_binary. */
1829 (for cmp (simple_comparison)
1830 (simplify
1831 (cmp (convert1?@2 addr@0) (convert2? addr@1))
1832 (with
1833 {
1834 HOST_WIDE_INT off0, off1;
1835 tree base0 = get_addr_base_and_unit_offset (TREE_OPERAND (@0, 0), &off0);
1836 tree base1 = get_addr_base_and_unit_offset (TREE_OPERAND (@1, 0), &off1);
1837 if (base0 && TREE_CODE (base0) == MEM_REF)
1838 {
1839 off0 += mem_ref_offset (base0).to_short_addr ();
1840 base0 = TREE_OPERAND (base0, 0);
1841 }
1842 if (base1 && TREE_CODE (base1) == MEM_REF)
1843 {
1844 off1 += mem_ref_offset (base1).to_short_addr ();
1845 base1 = TREE_OPERAND (base1, 0);
1846 }
1847 }
1848 (if (base0 && base1)
1849 (with
1850 {
1851 int equal = 2;
1852 if (decl_in_symtab_p (base0)
1853 && decl_in_symtab_p (base1))
1854 equal = symtab_node::get_create (base0)
1855 ->equal_address_to (symtab_node::get_create (base1));
1856 else if ((DECL_P (base0) || TREE_CODE (base0) == SSA_NAME)
1857 && (DECL_P (base1) || TREE_CODE (base1) == SSA_NAME))
1858 equal = (base0 == base1);
1859 }
1860 (if (equal == 1
1861 && (cmp == EQ_EXPR || cmp == NE_EXPR
1862 /* If the offsets are equal we can ignore overflow. */
1863 || off0 == off1
1864 || POINTER_TYPE_OVERFLOW_UNDEFINED
1865 /* Or if we compare using pointers to decls. */
1866 || (POINTER_TYPE_P (TREE_TYPE (@2))
1867 && DECL_P (base0))))
1868 (switch
1869 (if (cmp == EQ_EXPR)
1870 { constant_boolean_node (off0 == off1, type); })
1871 (if (cmp == NE_EXPR)
1872 { constant_boolean_node (off0 != off1, type); })
1873 (if (cmp == LT_EXPR)
1874 { constant_boolean_node (off0 < off1, type); })
1875 (if (cmp == LE_EXPR)
1876 { constant_boolean_node (off0 <= off1, type); })
1877 (if (cmp == GE_EXPR)
1878 { constant_boolean_node (off0 >= off1, type); })
1879 (if (cmp == GT_EXPR)
1880 { constant_boolean_node (off0 > off1, type); }))
1881 (if (equal == 0
1882 && DECL_P (base0) && DECL_P (base1)
1883 /* If we compare this as integers require equal offset. */
1884 && (!INTEGRAL_TYPE_P (TREE_TYPE (@2))
1885 || off0 == off1))
1886 (switch
1887 (if (cmp == EQ_EXPR)
1888 { constant_boolean_node (false, type); })
1889 (if (cmp == NE_EXPR)
1890 { constant_boolean_node (true, type); })))))))))
1891
1892 /* Non-equality compare simplifications from fold_binary */
1893 (for cmp (lt gt le ge)
1894 /* Comparisons with the highest or lowest possible integer of
1895 the specified precision will have known values. */
1896 (simplify
1897 (cmp (convert?@2 @0) INTEGER_CST@1)
1898 (if ((INTEGRAL_TYPE_P (TREE_TYPE (@1)) || POINTER_TYPE_P (TREE_TYPE (@1)))
1899 && tree_nop_conversion_p (TREE_TYPE (@2), TREE_TYPE (@0)))
1900 (with
1901 {
1902 tree arg1_type = TREE_TYPE (@1);
1903 unsigned int prec = TYPE_PRECISION (arg1_type);
1904 wide_int max = wi::max_value (arg1_type);
1905 wide_int signed_max = wi::max_value (prec, SIGNED);
1906 wide_int min = wi::min_value (arg1_type);
1907 }
1908 (switch
1909 (if (wi::eq_p (@1, max))
1910 (switch
1911 (if (cmp == GT_EXPR)
1912 { constant_boolean_node (false, type); })
1913 (if (cmp == GE_EXPR)
1914 (eq @2 @1))
1915 (if (cmp == LE_EXPR)
1916 { constant_boolean_node (true, type); })
1917 (if (cmp == LT_EXPR)
1918 (ne @2 @1))))
1919 (if (wi::eq_p (@1, min))
1920 (switch
1921 (if (cmp == LT_EXPR)
1922 { constant_boolean_node (false, type); })
1923 (if (cmp == LE_EXPR)
1924 (eq @2 @1))
1925 (if (cmp == GE_EXPR)
1926 { constant_boolean_node (true, type); })
1927 (if (cmp == GT_EXPR)
1928 (ne @2 @1))))
1929 (if (wi::eq_p (@1, max - 1))
1930 (switch
1931 (if (cmp == GT_EXPR)
1932 (eq @2 { wide_int_to_tree (TREE_TYPE (@1), wi::add (@1, 1)); }))
1933 (if (cmp == LE_EXPR)
1934 (ne @2 { wide_int_to_tree (TREE_TYPE (@1), wi::add (@1, 1)); }))))
1935 (if (wi::eq_p (@1, min + 1))
1936 (switch
1937 (if (cmp == GE_EXPR)
1938 (ne @2 { wide_int_to_tree (TREE_TYPE (@1), wi::sub (@1, 1)); }))
1939 (if (cmp == LT_EXPR)
1940 (eq @2 { wide_int_to_tree (TREE_TYPE (@1), wi::sub (@1, 1)); }))))
1941 (if (wi::eq_p (@1, signed_max)
1942 && TYPE_UNSIGNED (arg1_type)
1943 /* We will flip the signedness of the comparison operator
1944 associated with the mode of @1, so the sign bit is
1945 specified by this mode. Check that @1 is the signed
1946 max associated with this sign bit. */
1947 && prec == GET_MODE_PRECISION (TYPE_MODE (arg1_type))
1948 /* signed_type does not work on pointer types. */
1949 && INTEGRAL_TYPE_P (arg1_type))
1950 /* The following case also applies to X < signed_max+1
1951 and X >= signed_max+1 because previous transformations. */
1952 (if (cmp == LE_EXPR || cmp == GT_EXPR)
1953 (with { tree st = signed_type_for (arg1_type); }
1954 (if (cmp == LE_EXPR)
1955 (ge (convert:st @0) { build_zero_cst (st); })
1956 (lt (convert:st @0) { build_zero_cst (st); }))))))))))
1957
1958 (for cmp (unordered ordered unlt unle ungt unge uneq ltgt)
1959 /* If the second operand is NaN, the result is constant. */
1960 (simplify
1961 (cmp @0 REAL_CST@1)
1962 (if (REAL_VALUE_ISNAN (TREE_REAL_CST (@1))
1963 && (cmp != LTGT_EXPR || ! flag_trapping_math))
1964 { constant_boolean_node (cmp == ORDERED_EXPR || cmp == LTGT_EXPR
1965 ? false : true, type); })))
1966
1967 /* bool_var != 0 becomes bool_var. */
1968 (simplify
1969 (ne @0 integer_zerop)
1970 (if (TREE_CODE (TREE_TYPE (@0)) == BOOLEAN_TYPE
1971 && types_match (type, TREE_TYPE (@0)))
1972 (non_lvalue @0)))
1973 /* bool_var == 1 becomes bool_var. */
1974 (simplify
1975 (eq @0 integer_onep)
1976 (if (TREE_CODE (TREE_TYPE (@0)) == BOOLEAN_TYPE
1977 && types_match (type, TREE_TYPE (@0)))
1978 (non_lvalue @0)))
1979 /* Do not handle
1980 bool_var == 0 becomes !bool_var or
1981 bool_var != 1 becomes !bool_var
1982 here because that only is good in assignment context as long
1983 as we require a tcc_comparison in GIMPLE_CONDs where we'd
1984 replace if (x == 0) with tem = ~x; if (tem != 0) which is
1985 clearly less optimal and which we'll transform again in forwprop. */
1986
1987
1988 /* Simplification of math builtins. */
1989
1990 /* fold_builtin_logarithm */
1991 (if (flag_unsafe_math_optimizations)
1992 /* Special case, optimize logN(expN(x)) = x. */
1993 (for logs (LOG LOG2 LOG10)
1994 exps (EXP EXP2 EXP10)
1995 (simplify
1996 (logs (exps @0))
1997 @0))
1998 /* Optimize logN(func()) for various exponential functions. We
1999 want to determine the value "x" and the power "exponent" in
2000 order to transform logN(x**exponent) into exponent*logN(x). */
2001 (for logs (LOG LOG LOG LOG
2002 LOG2 LOG2 LOG2 LOG2
2003 LOG10 LOG10 LOG10 LOG10)
2004 exps (EXP EXP2 EXP10 POW10)
2005 (simplify
2006 (logs (exps @0))
2007 (with {
2008 tree x;
2009 switch (exps)
2010 {
2011 CASE_FLT_FN (BUILT_IN_EXP):
2012 /* Prepare to do logN(exp(exponent) -> exponent*logN(e). */
2013 x = build_real (type, real_value_truncate (TYPE_MODE (type),
2014 dconst_e ()));
2015 break;
2016 CASE_FLT_FN (BUILT_IN_EXP2):
2017 /* Prepare to do logN(exp2(exponent) -> exponent*logN(2). */
2018 x = build_real (type, dconst2);
2019 break;
2020 CASE_FLT_FN (BUILT_IN_EXP10):
2021 CASE_FLT_FN (BUILT_IN_POW10):
2022 /* Prepare to do logN(exp10(exponent) -> exponent*logN(10). */
2023 {
2024 REAL_VALUE_TYPE dconst10;
2025 real_from_integer (&dconst10, VOIDmode, 10, SIGNED);
2026 x = build_real (type, dconst10);
2027 }
2028 break;
2029 default:
2030 gcc_unreachable ();
2031 }
2032 }
2033 (mult (logs { x; }) @0))))
2034 (for logs (LOG LOG
2035 LOG2 LOG2
2036 LOG10 LOG10)
2037 exps (SQRT CBRT)
2038 (simplify
2039 (logs (exps @0))
2040 (with {
2041 tree x;
2042 switch (exps)
2043 {
2044 CASE_FLT_FN (BUILT_IN_SQRT):
2045 /* Prepare to do logN(sqrt(x) -> 0.5*logN(x). */
2046 x = build_real (type, dconsthalf);
2047 break;
2048 CASE_FLT_FN (BUILT_IN_CBRT):
2049 /* Prepare to do logN(cbrt(x) -> (1/3)*logN(x). */
2050 x = build_real (type, real_value_truncate (TYPE_MODE (type),
2051 dconst_third ()));
2052 break;
2053 default:
2054 gcc_unreachable ();
2055 }
2056 }
2057 (mult { x; } (logs @0)))))
2058 /* logN(pow(x,exponent) -> exponent*logN(x). */
2059 (for logs (LOG LOG2 LOG10)
2060 pows (POW)
2061 (simplify
2062 (logs (pows @0 @1))
2063 (mult @1 (logs @0)))))
2064
2065 /* Narrowing of arithmetic and logical operations.
2066
2067 These are conceptually similar to the transformations performed for
2068 the C/C++ front-ends by shorten_binary_op and shorten_compare. Long
2069 term we want to move all that code out of the front-ends into here. */
2070
2071 /* If we have a narrowing conversion of an arithmetic operation where
2072 both operands are widening conversions from the same type as the outer
2073 narrowing conversion. Then convert the innermost operands to a suitable
2074 unsigned type (to avoid introducing undefined behaviour), perform the
2075 operation and convert the result to the desired type. */
2076 (for op (plus minus)
2077 (simplify
2078 (convert (op:s (convert@2 @0) (convert@3 @1)))
2079 (if (INTEGRAL_TYPE_P (type)
2080 /* We check for type compatibility between @0 and @1 below,
2081 so there's no need to check that @1/@3 are integral types. */
2082 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
2083 && INTEGRAL_TYPE_P (TREE_TYPE (@2))
2084 /* The precision of the type of each operand must match the
2085 precision of the mode of each operand, similarly for the
2086 result. */
2087 && (TYPE_PRECISION (TREE_TYPE (@0))
2088 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@0))))
2089 && (TYPE_PRECISION (TREE_TYPE (@1))
2090 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@1))))
2091 && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
2092 /* The inner conversion must be a widening conversion. */
2093 && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0))
2094 && types_match (@0, @1)
2095 && types_match (@0, type))
2096 (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
2097 (convert (op @0 @1))
2098 (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
2099 (convert (op (convert:utype @0) (convert:utype @1))))))))
2100
2101 /* This is another case of narrowing, specifically when there's an outer
2102 BIT_AND_EXPR which masks off bits outside the type of the innermost
2103 operands. Like the previous case we have to convert the operands
2104 to unsigned types to avoid introducing undefined behaviour for the
2105 arithmetic operation. */
2106 (for op (minus plus)
2107 (simplify
2108 (bit_and (op:s (convert@2 @0) (convert@3 @1)) INTEGER_CST@4)
2109 (if (INTEGRAL_TYPE_P (type)
2110 /* We check for type compatibility between @0 and @1 below,
2111 so there's no need to check that @1/@3 are integral types. */
2112 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
2113 && INTEGRAL_TYPE_P (TREE_TYPE (@2))
2114 /* The precision of the type of each operand must match the
2115 precision of the mode of each operand, similarly for the
2116 result. */
2117 && (TYPE_PRECISION (TREE_TYPE (@0))
2118 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@0))))
2119 && (TYPE_PRECISION (TREE_TYPE (@1))
2120 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@1))))
2121 && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
2122 /* The inner conversion must be a widening conversion. */
2123 && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0))
2124 && types_match (@0, @1)
2125 && (tree_int_cst_min_precision (@4, TYPE_SIGN (TREE_TYPE (@0)))
2126 <= TYPE_PRECISION (TREE_TYPE (@0)))
2127 && (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))
2128 || tree_int_cst_sgn (@4) >= 0))
2129 (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
2130 (with { tree ntype = TREE_TYPE (@0); }
2131 (convert (bit_and (op @0 @1) (convert:ntype @4))))
2132 (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
2133 (convert (bit_and (op (convert:utype @0) (convert:utype @1))
2134 (convert:utype @4))))))))