real.h (HONOR_NANS): Replace macro with 3 overloaded declarations.
[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 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
30 real_zerop real_onep real_minus_onep
31 CONSTANT_CLASS_P
32 tree_expr_nonnegative_p)
33
34 /* Operator lists. */
35 (define_operator_list tcc_comparison
36 lt le eq ne ge gt unordered ordered unlt unle ungt unge uneq ltgt)
37 (define_operator_list inverted_tcc_comparison
38 ge gt ne eq lt le ordered unordered ge gt le lt ltgt uneq)
39 (define_operator_list inverted_tcc_comparison_with_nans
40 unge ungt ne eq unlt unle ordered unordered ge gt le lt ltgt uneq)
41
42
43 /* Simplifications of operations with one constant operand and
44 simplifications to constants or single values. */
45
46 (for op (plus pointer_plus minus bit_ior bit_xor)
47 (simplify
48 (op @0 integer_zerop)
49 (non_lvalue @0)))
50
51 /* 0 +p index -> (type)index */
52 (simplify
53 (pointer_plus integer_zerop @1)
54 (non_lvalue (convert @1)))
55
56 /* See if ARG1 is zero and X + ARG1 reduces to X.
57 Likewise if the operands are reversed. */
58 (simplify
59 (plus:c @0 real_zerop@1)
60 (if (fold_real_zero_addition_p (type, @1, 0))
61 (non_lvalue @0)))
62
63 /* See if ARG1 is zero and X - ARG1 reduces to X. */
64 (simplify
65 (minus @0 real_zerop@1)
66 (if (fold_real_zero_addition_p (type, @1, 1))
67 (non_lvalue @0)))
68
69 /* Simplify x - x.
70 This is unsafe for certain floats even in non-IEEE formats.
71 In IEEE, it is unsafe because it does wrong for NaNs.
72 Also note that operand_equal_p is always false if an operand
73 is volatile. */
74 (simplify
75 (minus @0 @0)
76 (if (!FLOAT_TYPE_P (type) || !HONOR_NANS (type))
77 { build_zero_cst (type); }))
78
79 (simplify
80 (mult @0 integer_zerop@1)
81 @1)
82
83 /* Maybe fold x * 0 to 0. The expressions aren't the same
84 when x is NaN, since x * 0 is also NaN. Nor are they the
85 same in modes with signed zeros, since multiplying a
86 negative value by 0 gives -0, not +0. */
87 (simplify
88 (mult @0 real_zerop@1)
89 (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (element_mode (type)))
90 @1))
91
92 /* In IEEE floating point, x*1 is not equivalent to x for snans.
93 Likewise for complex arithmetic with signed zeros. */
94 (simplify
95 (mult @0 real_onep)
96 (if (!HONOR_SNANS (element_mode (type))
97 && (!HONOR_SIGNED_ZEROS (element_mode (type))
98 || !COMPLEX_FLOAT_TYPE_P (type)))
99 (non_lvalue @0)))
100
101 /* Transform x * -1.0 into -x. */
102 (simplify
103 (mult @0 real_minus_onep)
104 (if (!HONOR_SNANS (element_mode (type))
105 && (!HONOR_SIGNED_ZEROS (element_mode (type))
106 || !COMPLEX_FLOAT_TYPE_P (type)))
107 (negate @0)))
108
109 /* Make sure to preserve divisions by zero. This is the reason why
110 we don't simplify x / x to 1 or 0 / x to 0. */
111 (for op (mult trunc_div ceil_div floor_div round_div exact_div)
112 (simplify
113 (op @0 integer_onep)
114 (non_lvalue @0)))
115
116 /* X / -1 is -X. */
117 (for div (trunc_div ceil_div floor_div round_div exact_div)
118 (simplify
119 (div @0 integer_minus_onep@1)
120 (if (!TYPE_UNSIGNED (type))
121 (negate @0))))
122
123 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
124 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
125 (simplify
126 (floor_div @0 @1)
127 (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
128 && TYPE_UNSIGNED (type))
129 (trunc_div @0 @1)))
130
131 /* Combine two successive divisions. Note that combining ceil_div
132 and floor_div is trickier and combining round_div even more so. */
133 (for div (trunc_div exact_div)
134 (simplify
135 (div (div @0 INTEGER_CST@1) INTEGER_CST@2)
136 (with {
137 bool overflow_p;
138 wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p);
139 }
140 (if (!overflow_p)
141 (div @0 { wide_int_to_tree (type, mul); }))
142 (if (overflow_p
143 && (TYPE_UNSIGNED (type)
144 || mul != wi::min_value (TYPE_PRECISION (type), SIGNED)))
145 { build_zero_cst (type); }))))
146
147 /* Optimize A / A to 1.0 if we don't care about
148 NaNs or Infinities. */
149 (simplify
150 (rdiv @0 @0)
151 (if (FLOAT_TYPE_P (type)
152 && ! HONOR_NANS (type)
153 && ! HONOR_INFINITIES (element_mode (type)))
154 { build_one_cst (type); }))
155
156 /* Optimize -A / A to -1.0 if we don't care about
157 NaNs or Infinities. */
158 (simplify
159 (rdiv:c @0 (negate @0))
160 (if (FLOAT_TYPE_P (type)
161 && ! HONOR_NANS (type)
162 && ! HONOR_INFINITIES (element_mode (type)))
163 { build_minus_one_cst (type); }))
164
165 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
166 (simplify
167 (rdiv @0 real_onep)
168 (if (!HONOR_SNANS (element_mode (type)))
169 (non_lvalue @0)))
170
171 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
172 (simplify
173 (rdiv @0 real_minus_onep)
174 (if (!HONOR_SNANS (element_mode (type)))
175 (negate @0)))
176
177 /* If ARG1 is a constant, we can convert this to a multiply by the
178 reciprocal. This does not have the same rounding properties,
179 so only do this if -freciprocal-math. We can actually
180 always safely do it if ARG1 is a power of two, but it's hard to
181 tell if it is or not in a portable manner. */
182 (for cst (REAL_CST COMPLEX_CST VECTOR_CST)
183 (simplify
184 (rdiv @0 cst@1)
185 (if (optimize)
186 (if (flag_reciprocal_math
187 && !real_zerop (@1))
188 (with
189 { tree tem = fold_binary (RDIV_EXPR, type, build_one_cst (type), @1); }
190 (if (tem)
191 (mult @0 { tem; } ))))
192 (if (cst != COMPLEX_CST)
193 (with { tree inverse = exact_inverse (type, @1); }
194 (if (inverse)
195 (mult @0 { inverse; } )))))))
196
197 /* Same applies to modulo operations, but fold is inconsistent here
198 and simplifies 0 % x to 0, only preserving literal 0 % 0. */
199 (for mod (ceil_mod floor_mod round_mod trunc_mod)
200 /* 0 % X is always zero. */
201 (simplify
202 (mod integer_zerop@0 @1)
203 /* But not for 0 % 0 so that we can get the proper warnings and errors. */
204 (if (!integer_zerop (@1))
205 @0))
206 /* X % 1 is always zero. */
207 (simplify
208 (mod @0 integer_onep)
209 { build_zero_cst (type); })
210 /* X % -1 is zero. */
211 (simplify
212 (mod @0 integer_minus_onep@1)
213 (if (!TYPE_UNSIGNED (type))
214 { build_zero_cst (type); })))
215
216 /* X % -C is the same as X % C. */
217 (simplify
218 (trunc_mod @0 INTEGER_CST@1)
219 (if (TYPE_SIGN (type) == SIGNED
220 && !TREE_OVERFLOW (@1)
221 && wi::neg_p (@1)
222 && !TYPE_OVERFLOW_TRAPS (type)
223 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
224 && !sign_bit_p (@1, @1))
225 (trunc_mod @0 (negate @1))))
226
227 /* x | ~0 -> ~0 */
228 (simplify
229 (bit_ior @0 integer_all_onesp@1)
230 @1)
231
232 /* x & 0 -> 0 */
233 (simplify
234 (bit_and @0 integer_zerop@1)
235 @1)
236
237 /* x ^ x -> 0 */
238 (simplify
239 (bit_xor @0 @0)
240 { build_zero_cst (type); })
241
242 /* Canonicalize X ^ ~0 to ~X. */
243 (simplify
244 (bit_xor @0 integer_all_onesp@1)
245 (bit_not @0))
246
247 /* x & ~0 -> x */
248 (simplify
249 (bit_and @0 integer_all_onesp)
250 (non_lvalue @0))
251
252 /* x & x -> x, x | x -> x */
253 (for bitop (bit_and bit_ior)
254 (simplify
255 (bitop @0 @0)
256 (non_lvalue @0)))
257
258 (simplify
259 (abs (negate @0))
260 (abs @0))
261 (simplify
262 (abs tree_expr_nonnegative_p@0)
263 @0)
264
265
266 /* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
267 when profitable.
268 For bitwise binary operations apply operand conversions to the
269 binary operation result instead of to the operands. This allows
270 to combine successive conversions and bitwise binary operations.
271 We combine the above two cases by using a conditional convert. */
272 (for bitop (bit_and bit_ior bit_xor)
273 (simplify
274 (bitop (convert @0) (convert? @1))
275 (if (((TREE_CODE (@1) == INTEGER_CST
276 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
277 && int_fits_type_p (@1, TREE_TYPE (@0)))
278 || (GIMPLE && types_compatible_p (TREE_TYPE (@0), TREE_TYPE (@1)))
279 || (GENERIC && TREE_TYPE (@0) == TREE_TYPE (@1)))
280 /* ??? This transform conflicts with fold-const.c doing
281 Convert (T)(x & c) into (T)x & (T)c, if c is an integer
282 constants (if x has signed type, the sign bit cannot be set
283 in c). This folds extension into the BIT_AND_EXPR.
284 Restrict it to GIMPLE to avoid endless recursions. */
285 && (bitop != BIT_AND_EXPR || GIMPLE)
286 && (/* That's a good idea if the conversion widens the operand, thus
287 after hoisting the conversion the operation will be narrower. */
288 TYPE_PRECISION (TREE_TYPE (@0)) < TYPE_PRECISION (type)
289 /* It's also a good idea if the conversion is to a non-integer
290 mode. */
291 || GET_MODE_CLASS (TYPE_MODE (type)) != MODE_INT
292 /* Or if the precision of TO is not the same as the precision
293 of its mode. */
294 || TYPE_PRECISION (type) != GET_MODE_PRECISION (TYPE_MODE (type))))
295 (convert (bitop @0 (convert @1))))))
296
297 /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */
298 (for bitop (bit_and bit_ior bit_xor)
299 (simplify
300 (bitop (bit_and:c @0 @1) (bit_and @2 @1))
301 (bit_and (bitop @0 @2) @1)))
302
303 /* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
304 (simplify
305 (bit_and (bit_ior @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
306 (bit_ior (bit_and @0 @2) (bit_and @1 @2)))
307
308 /* Combine successive equal operations with constants. */
309 (for bitop (bit_and bit_ior bit_xor)
310 (simplify
311 (bitop (bitop @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
312 (bitop @0 (bitop @1 @2))))
313
314 /* Try simple folding for X op !X, and X op X with the help
315 of the truth_valued_p and logical_inverted_value predicates. */
316 (match truth_valued_p
317 @0
318 (if (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1)))
319 (for op (tcc_comparison truth_and truth_andif truth_or truth_orif truth_xor)
320 (match truth_valued_p
321 (op @0 @1)))
322 (match truth_valued_p
323 (truth_not @0))
324
325 (match (logical_inverted_value @0)
326 (bit_not truth_valued_p@0))
327 (match (logical_inverted_value @0)
328 (eq @0 integer_zerop))
329 (match (logical_inverted_value @0)
330 (ne truth_valued_p@0 integer_truep))
331 (match (logical_inverted_value @0)
332 (bit_xor truth_valued_p@0 integer_truep))
333
334 /* X & !X -> 0. */
335 (simplify
336 (bit_and:c @0 (logical_inverted_value @0))
337 { build_zero_cst (type); })
338 /* X | !X and X ^ !X -> 1, , if X is truth-valued. */
339 (for op (bit_ior bit_xor)
340 (simplify
341 (op:c truth_valued_p@0 (logical_inverted_value @0))
342 { constant_boolean_node (true, type); }))
343
344 (for bitop (bit_and bit_ior)
345 rbitop (bit_ior bit_and)
346 /* (x | y) & x -> x */
347 /* (x & y) | x -> x */
348 (simplify
349 (bitop:c (rbitop:c @0 @1) @0)
350 @0)
351 /* (~x | y) & x -> x & y */
352 /* (~x & y) | x -> x | y */
353 (simplify
354 (bitop:c (rbitop:c (bit_not @0) @1) @0)
355 (bitop @0 @1)))
356
357 /* If arg1 and arg2 are booleans (or any single bit type)
358 then try to simplify:
359
360 (~X & Y) -> X < Y
361 (X & ~Y) -> Y < X
362 (~X | Y) -> X <= Y
363 (X | ~Y) -> Y <= X
364
365 But only do this if our result feeds into a comparison as
366 this transformation is not always a win, particularly on
367 targets with and-not instructions.
368 -> simplify_bitwise_binary_boolean */
369 (simplify
370 (ne (bit_and:c (bit_not @0) @1) integer_zerop)
371 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
372 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
373 (lt @0 @1)))
374 (simplify
375 (ne (bit_ior:c (bit_not @0) @1) integer_zerop)
376 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
377 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
378 (le @0 @1)))
379
380 /* ~~x -> x */
381 (simplify
382 (bit_not (bit_not @0))
383 @0)
384
385
386 /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)). */
387 (simplify
388 (pointer_plus (pointer_plus@2 @0 @1) @3)
389 (if (TREE_CODE (@2) != SSA_NAME || has_single_use (@2))
390 (pointer_plus @0 (plus @1 @3))))
391
392 /* Pattern match
393 tem1 = (long) ptr1;
394 tem2 = (long) ptr2;
395 tem3 = tem2 - tem1;
396 tem4 = (unsigned long) tem3;
397 tem5 = ptr1 + tem4;
398 and produce
399 tem5 = ptr2; */
400 (simplify
401 (pointer_plus @0 (convert?@2 (minus@3 (convert @1) (convert @0))))
402 /* Conditionally look through a sign-changing conversion. */
403 (if (TYPE_PRECISION (TREE_TYPE (@2)) == TYPE_PRECISION (TREE_TYPE (@3))
404 && ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@1)))
405 || (GENERIC && type == TREE_TYPE (@1))))
406 @1))
407
408 /* Pattern match
409 tem = (sizetype) ptr;
410 tem = tem & algn;
411 tem = -tem;
412 ... = ptr p+ tem;
413 and produce the simpler and easier to analyze with respect to alignment
414 ... = ptr & ~algn; */
415 (simplify
416 (pointer_plus @0 (negate (bit_and (convert @0) INTEGER_CST@1)))
417 (with { tree algn = wide_int_to_tree (TREE_TYPE (@0), wi::bit_not (@1)); }
418 (bit_and @0 { algn; })))
419
420
421 /* We can't reassociate at all for saturating types. */
422 (if (!TYPE_SATURATING (type))
423
424 /* Contract negates. */
425 /* A + (-B) -> A - B */
426 (simplify
427 (plus:c (convert1? @0) (convert2? (negate @1)))
428 /* Apply STRIP_NOPS on @0 and the negate. */
429 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
430 && tree_nop_conversion_p (type, TREE_TYPE (@1))
431 && !TYPE_OVERFLOW_SANITIZED (type))
432 (minus (convert @0) (convert @1))))
433 /* A - (-B) -> A + B */
434 (simplify
435 (minus (convert1? @0) (convert2? (negate @1)))
436 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
437 && tree_nop_conversion_p (type, TREE_TYPE (@1))
438 && !TYPE_OVERFLOW_SANITIZED (type))
439 (plus (convert @0) (convert @1))))
440 /* -(-A) -> A */
441 (simplify
442 (negate (convert? (negate @1)))
443 (if (tree_nop_conversion_p (type, TREE_TYPE (@1))
444 && !TYPE_OVERFLOW_SANITIZED (type))
445 (convert @1)))
446
447 /* We can't reassociate floating-point or fixed-point plus or minus
448 because of saturation to +-Inf. */
449 (if (!FLOAT_TYPE_P (type) && !FIXED_POINT_TYPE_P (type))
450
451 /* Match patterns that allow contracting a plus-minus pair
452 irrespective of overflow issues. */
453 /* (A +- B) - A -> +- B */
454 /* (A +- B) -+ B -> A */
455 /* A - (A +- B) -> -+ B */
456 /* A +- (B -+ A) -> +- B */
457 (simplify
458 (minus (plus:c @0 @1) @0)
459 @1)
460 (simplify
461 (minus (minus @0 @1) @0)
462 (negate @1))
463 (simplify
464 (plus:c (minus @0 @1) @1)
465 @0)
466 (simplify
467 (minus @0 (plus:c @0 @1))
468 (negate @1))
469 (simplify
470 (minus @0 (minus @0 @1))
471 @1)
472
473 /* (A +- CST) +- CST -> A + CST */
474 (for outer_op (plus minus)
475 (for inner_op (plus minus)
476 (simplify
477 (outer_op (inner_op @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
478 /* If the constant operation overflows we cannot do the transform
479 as we would introduce undefined overflow, for example
480 with (a - 1) + INT_MIN. */
481 (with { tree cst = fold_binary (outer_op == inner_op
482 ? PLUS_EXPR : MINUS_EXPR, type, @1, @2); }
483 (if (cst && !TREE_OVERFLOW (cst))
484 (inner_op @0 { cst; } ))))))
485
486 /* (CST - A) +- CST -> CST - A */
487 (for outer_op (plus minus)
488 (simplify
489 (outer_op (minus CONSTANT_CLASS_P@1 @0) CONSTANT_CLASS_P@2)
490 (with { tree cst = fold_binary (outer_op, type, @1, @2); }
491 (if (cst && !TREE_OVERFLOW (cst))
492 (minus { cst; } @0)))))
493
494 /* ~A + A -> -1 */
495 (simplify
496 (plus:c (bit_not @0) @0)
497 (if (!TYPE_OVERFLOW_TRAPS (type))
498 { build_all_ones_cst (type); }))
499
500 /* ~A + 1 -> -A */
501 (simplify
502 (plus (convert? (bit_not @0)) integer_each_onep)
503 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
504 (negate (convert @0))))
505
506 /* -A - 1 -> ~A */
507 (simplify
508 (minus (convert? (negate @0)) integer_each_onep)
509 (if (!TYPE_OVERFLOW_TRAPS (type)
510 && tree_nop_conversion_p (type, TREE_TYPE (@0)))
511 (bit_not (convert @0))))
512
513 /* -1 - A -> ~A */
514 (simplify
515 (minus integer_all_onesp @0)
516 (if (TREE_CODE (type) != COMPLEX_TYPE)
517 (bit_not @0)))
518
519 /* (T)(P + A) - (T)P -> (T) A */
520 (for add (plus pointer_plus)
521 (simplify
522 (minus (convert (add @0 @1))
523 (convert @0))
524 (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
525 /* For integer types, if A has a smaller type
526 than T the result depends on the possible
527 overflow in P + A.
528 E.g. T=size_t, A=(unsigned)429497295, P>0.
529 However, if an overflow in P + A would cause
530 undefined behavior, we can assume that there
531 is no overflow. */
532 || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
533 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
534 /* For pointer types, if the conversion of A to the
535 final type requires a sign- or zero-extension,
536 then we have to punt - it is not defined which
537 one is correct. */
538 || (POINTER_TYPE_P (TREE_TYPE (@0))
539 && TREE_CODE (@1) == INTEGER_CST
540 && tree_int_cst_sign_bit (@1) == 0))
541 (convert @1))))))
542
543
544 /* Simplifications of MIN_EXPR and MAX_EXPR. */
545
546 (for minmax (min max)
547 (simplify
548 (minmax @0 @0)
549 @0))
550 (simplify
551 (min @0 @1)
552 (if (INTEGRAL_TYPE_P (type)
553 && TYPE_MIN_VALUE (type)
554 && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
555 @1))
556 (simplify
557 (max @0 @1)
558 (if (INTEGRAL_TYPE_P (type)
559 && TYPE_MAX_VALUE (type)
560 && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
561 @1))
562
563
564 /* Simplifications of shift and rotates. */
565
566 (for rotate (lrotate rrotate)
567 (simplify
568 (rotate integer_all_onesp@0 @1)
569 @0))
570
571 /* Optimize -1 >> x for arithmetic right shifts. */
572 (simplify
573 (rshift integer_all_onesp@0 @1)
574 (if (!TYPE_UNSIGNED (type)
575 && tree_expr_nonnegative_p (@1))
576 @0))
577
578 (for shiftrotate (lrotate rrotate lshift rshift)
579 (simplify
580 (shiftrotate @0 integer_zerop)
581 (non_lvalue @0))
582 (simplify
583 (shiftrotate integer_zerop@0 @1)
584 @0)
585 /* Prefer vector1 << scalar to vector1 << vector2
586 if vector2 is uniform. */
587 (for vec (VECTOR_CST CONSTRUCTOR)
588 (simplify
589 (shiftrotate @0 vec@1)
590 (with { tree tem = uniform_vector_p (@1); }
591 (if (tem)
592 (shiftrotate @0 { tem; }))))))
593
594 /* Rewrite an LROTATE_EXPR by a constant into an
595 RROTATE_EXPR by a new constant. */
596 (simplify
597 (lrotate @0 INTEGER_CST@1)
598 (rrotate @0 { fold_binary (MINUS_EXPR, TREE_TYPE (@1),
599 build_int_cst (TREE_TYPE (@1),
600 element_precision (type)), @1); }))
601
602
603 /* Simplifications of conversions. */
604
605 /* Basic strip-useless-type-conversions / strip_nops. */
606 (for cvt (convert view_convert float fix_trunc)
607 (simplify
608 (cvt @0)
609 (if ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@0)))
610 || (GENERIC && type == TREE_TYPE (@0)))
611 @0)))
612
613 /* Contract view-conversions. */
614 (simplify
615 (view_convert (view_convert @0))
616 (view_convert @0))
617
618 /* For integral conversions with the same precision or pointer
619 conversions use a NOP_EXPR instead. */
620 (simplify
621 (view_convert @0)
622 (if ((INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
623 && (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
624 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (@0)))
625 (convert @0)))
626
627 /* Strip inner integral conversions that do not change precision or size. */
628 (simplify
629 (view_convert (convert@0 @1))
630 (if ((INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
631 && (INTEGRAL_TYPE_P (TREE_TYPE (@1)) || POINTER_TYPE_P (TREE_TYPE (@1)))
632 && (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1)))
633 && (TYPE_SIZE (TREE_TYPE (@0)) == TYPE_SIZE (TREE_TYPE (@1))))
634 (view_convert @1)))
635
636 /* Re-association barriers around constants and other re-association
637 barriers can be removed. */
638 (simplify
639 (paren CONSTANT_CLASS_P@0)
640 @0)
641 (simplify
642 (paren (paren@1 @0))
643 @1)
644
645 /* Handle cases of two conversions in a row. */
646 (for ocvt (convert float fix_trunc)
647 (for icvt (convert float)
648 (simplify
649 (ocvt (icvt@1 @0))
650 (with
651 {
652 tree inside_type = TREE_TYPE (@0);
653 tree inter_type = TREE_TYPE (@1);
654 int inside_int = INTEGRAL_TYPE_P (inside_type);
655 int inside_ptr = POINTER_TYPE_P (inside_type);
656 int inside_float = FLOAT_TYPE_P (inside_type);
657 int inside_vec = VECTOR_TYPE_P (inside_type);
658 unsigned int inside_prec = TYPE_PRECISION (inside_type);
659 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
660 int inter_int = INTEGRAL_TYPE_P (inter_type);
661 int inter_ptr = POINTER_TYPE_P (inter_type);
662 int inter_float = FLOAT_TYPE_P (inter_type);
663 int inter_vec = VECTOR_TYPE_P (inter_type);
664 unsigned int inter_prec = TYPE_PRECISION (inter_type);
665 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
666 int final_int = INTEGRAL_TYPE_P (type);
667 int final_ptr = POINTER_TYPE_P (type);
668 int final_float = FLOAT_TYPE_P (type);
669 int final_vec = VECTOR_TYPE_P (type);
670 unsigned int final_prec = TYPE_PRECISION (type);
671 int final_unsignedp = TYPE_UNSIGNED (type);
672 }
673 /* In addition to the cases of two conversions in a row
674 handled below, if we are converting something to its own
675 type via an object of identical or wider precision, neither
676 conversion is needed. */
677 (if (((GIMPLE && useless_type_conversion_p (type, inside_type))
678 || (GENERIC
679 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (inside_type)))
680 && (((inter_int || inter_ptr) && final_int)
681 || (inter_float && final_float))
682 && inter_prec >= final_prec)
683 (ocvt @0))
684
685 /* Likewise, if the intermediate and initial types are either both
686 float or both integer, we don't need the middle conversion if the
687 former is wider than the latter and doesn't change the signedness
688 (for integers). Avoid this if the final type is a pointer since
689 then we sometimes need the middle conversion. Likewise if the
690 final type has a precision not equal to the size of its mode. */
691 (if (((inter_int && inside_int)
692 || (inter_float && inside_float)
693 || (inter_vec && inside_vec))
694 && inter_prec >= inside_prec
695 && (inter_float || inter_vec
696 || inter_unsignedp == inside_unsignedp)
697 && ! (final_prec != GET_MODE_PRECISION (element_mode (type))
698 && element_mode (type) == element_mode (inter_type))
699 && ! final_ptr
700 && (! final_vec || inter_prec == inside_prec))
701 (ocvt @0))
702
703 /* If we have a sign-extension of a zero-extended value, we can
704 replace that by a single zero-extension. Likewise if the
705 final conversion does not change precision we can drop the
706 intermediate conversion. */
707 (if (inside_int && inter_int && final_int
708 && ((inside_prec < inter_prec && inter_prec < final_prec
709 && inside_unsignedp && !inter_unsignedp)
710 || final_prec == inter_prec))
711 (ocvt @0))
712
713 /* Two conversions in a row are not needed unless:
714 - some conversion is floating-point (overstrict for now), or
715 - some conversion is a vector (overstrict for now), or
716 - the intermediate type is narrower than both initial and
717 final, or
718 - the intermediate type and innermost type differ in signedness,
719 and the outermost type is wider than the intermediate, or
720 - the initial type is a pointer type and the precisions of the
721 intermediate and final types differ, or
722 - the final type is a pointer type and the precisions of the
723 initial and intermediate types differ. */
724 (if (! inside_float && ! inter_float && ! final_float
725 && ! inside_vec && ! inter_vec && ! final_vec
726 && (inter_prec >= inside_prec || inter_prec >= final_prec)
727 && ! (inside_int && inter_int
728 && inter_unsignedp != inside_unsignedp
729 && inter_prec < final_prec)
730 && ((inter_unsignedp && inter_prec > inside_prec)
731 == (final_unsignedp && final_prec > inter_prec))
732 && ! (inside_ptr && inter_prec != final_prec)
733 && ! (final_ptr && inside_prec != inter_prec)
734 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
735 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
736 (ocvt @0))
737
738 /* A truncation to an unsigned type (a zero-extension) should be
739 canonicalized as bitwise and of a mask. */
740 (if (final_int && inter_int && inside_int
741 && final_prec == inside_prec
742 && final_prec > inter_prec
743 && inter_unsignedp)
744 (convert (bit_and @0 { wide_int_to_tree
745 (inside_type,
746 wi::mask (inter_prec, false,
747 TYPE_PRECISION (inside_type))); })))
748
749 /* If we are converting an integer to a floating-point that can
750 represent it exactly and back to an integer, we can skip the
751 floating-point conversion. */
752 (if (inside_int && inter_float && final_int &&
753 (unsigned) significand_size (TYPE_MODE (inter_type))
754 >= inside_prec - !inside_unsignedp)
755 (convert @0))))))
756
757 /* If we have a narrowing conversion to an integral type that is fed by a
758 BIT_AND_EXPR, we might be able to remove the BIT_AND_EXPR if it merely
759 masks off bits outside the final type (and nothing else). */
760 (simplify
761 (convert (bit_and @0 INTEGER_CST@1))
762 (if (INTEGRAL_TYPE_P (type)
763 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
764 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (@0))
765 && operand_equal_p (@1, build_low_bits_mask (TREE_TYPE (@1),
766 TYPE_PRECISION (type)), 0))
767 (convert @0)))
768
769
770 /* (X /[ex] A) * A -> X. */
771 (simplify
772 (mult (convert? (exact_div @0 @1)) @1)
773 /* Look through a sign-changing conversion. */
774 (if (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type))
775 (convert @0)))
776
777 /* Canonicalization of binary operations. */
778
779 /* Convert X + -C into X - C. */
780 (simplify
781 (plus @0 REAL_CST@1)
782 (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
783 (with { tree tem = fold_unary (NEGATE_EXPR, type, @1); }
784 (if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
785 (minus @0 { tem; })))))
786
787 /* Convert x+x into x*2.0. */
788 (simplify
789 (plus @0 @0)
790 (if (SCALAR_FLOAT_TYPE_P (type))
791 (mult @0 { build_real (type, dconst2); })))
792
793 (simplify
794 (minus integer_zerop @1)
795 (negate @1))
796
797 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
798 ARG0 is zero and X + ARG0 reduces to X, since that would mean
799 (-ARG1 + ARG0) reduces to -ARG1. */
800 (simplify
801 (minus real_zerop@0 @1)
802 (if (fold_real_zero_addition_p (type, @0, 0))
803 (negate @1)))
804
805 /* Transform x * -1 into -x. */
806 (simplify
807 (mult @0 integer_minus_onep)
808 (negate @0))
809
810 /* COMPLEX_EXPR and REALPART/IMAGPART_EXPR cancellations. */
811 (simplify
812 (complex (realpart @0) (imagpart @0))
813 @0)
814 (simplify
815 (realpart (complex @0 @1))
816 @0)
817 (simplify
818 (imagpart (complex @0 @1))
819 @1)
820
821
822 /* BSWAP simplifications, transforms checked by gcc.dg/builtin-bswap-8.c. */
823 (for bswap (BUILT_IN_BSWAP16 BUILT_IN_BSWAP32 BUILT_IN_BSWAP64)
824 (simplify
825 (bswap (bswap @0))
826 @0)
827 (simplify
828 (bswap (bit_not (bswap @0)))
829 (bit_not @0))
830 (for bitop (bit_xor bit_ior bit_and)
831 (simplify
832 (bswap (bitop:c (bswap @0) @1))
833 (bitop @0 (bswap @1)))))
834
835
836 /* Combine COND_EXPRs and VEC_COND_EXPRs. */
837
838 /* Simplify constant conditions.
839 Only optimize constant conditions when the selected branch
840 has the same type as the COND_EXPR. This avoids optimizing
841 away "c ? x : throw", where the throw has a void type.
842 Note that we cannot throw away the fold-const.c variant nor
843 this one as we depend on doing this transform before possibly
844 A ? B : B -> B triggers and the fold-const.c one can optimize
845 0 ? A : B to B even if A has side-effects. Something
846 genmatch cannot handle. */
847 (simplify
848 (cond INTEGER_CST@0 @1 @2)
849 (if (integer_zerop (@0)
850 && (!VOID_TYPE_P (TREE_TYPE (@2))
851 || VOID_TYPE_P (type)))
852 @2)
853 (if (!integer_zerop (@0)
854 && (!VOID_TYPE_P (TREE_TYPE (@1))
855 || VOID_TYPE_P (type)))
856 @1))
857 (simplify
858 (vec_cond VECTOR_CST@0 @1 @2)
859 (if (integer_all_onesp (@0))
860 @1)
861 (if (integer_zerop (@0))
862 @2))
863
864 (for cnd (cond vec_cond)
865 /* A ? B : (A ? X : C) -> A ? B : C. */
866 (simplify
867 (cnd @0 (cnd @0 @1 @2) @3)
868 (cnd @0 @1 @3))
869 (simplify
870 (cnd @0 @1 (cnd @0 @2 @3))
871 (cnd @0 @1 @3))
872
873 /* A ? B : B -> B. */
874 (simplify
875 (cnd @0 @1 @1)
876 @1)
877
878 /* !A ? B : C -> A ? C : B. */
879 (simplify
880 (cnd (logical_inverted_value truth_valued_p@0) @1 @2)
881 (cnd @0 @2 @1)))
882
883
884 /* Simplifications of comparisons. */
885
886 /* We can simplify a logical negation of a comparison to the
887 inverted comparison. As we cannot compute an expression
888 operator using invert_tree_comparison we have to simulate
889 that with expression code iteration. */
890 (for cmp (tcc_comparison)
891 icmp (inverted_tcc_comparison)
892 ncmp (inverted_tcc_comparison_with_nans)
893 /* Ideally we'd like to combine the following two patterns
894 and handle some more cases by using
895 (logical_inverted_value (cmp @0 @1))
896 here but for that genmatch would need to "inline" that.
897 For now implement what forward_propagate_comparison did. */
898 (simplify
899 (bit_not (cmp @0 @1))
900 (if (VECTOR_TYPE_P (type)
901 || (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1))
902 /* Comparison inversion may be impossible for trapping math,
903 invert_tree_comparison will tell us. But we can't use
904 a computed operator in the replacement tree thus we have
905 to play the trick below. */
906 (with { enum tree_code ic = invert_tree_comparison
907 (cmp, HONOR_NANS (@0)); }
908 (if (ic == icmp)
909 (icmp @0 @1))
910 (if (ic == ncmp)
911 (ncmp @0 @1)))))
912 (simplify
913 (bit_xor (cmp @0 @1) integer_truep)
914 (with { enum tree_code ic = invert_tree_comparison
915 (cmp, HONOR_NANS (@0)); }
916 (if (ic == icmp)
917 (icmp @0 @1))
918 (if (ic == ncmp)
919 (ncmp @0 @1)))))
920
921
922 /* Simplification of math builtins. */
923
924 (define_operator_list LOG BUILT_IN_LOGF BUILT_IN_LOG BUILT_IN_LOGL)
925 (define_operator_list EXP BUILT_IN_EXPF BUILT_IN_EXP BUILT_IN_EXPL)
926 (define_operator_list LOG2 BUILT_IN_LOG2F BUILT_IN_LOG2 BUILT_IN_LOG2L)
927 (define_operator_list EXP2 BUILT_IN_EXP2F BUILT_IN_EXP2 BUILT_IN_EXP2L)
928 (define_operator_list LOG10 BUILT_IN_LOG10F BUILT_IN_LOG10 BUILT_IN_LOG10L)
929 (define_operator_list EXP10 BUILT_IN_EXP10F BUILT_IN_EXP10 BUILT_IN_EXP10L)
930 (define_operator_list POW BUILT_IN_POWF BUILT_IN_POW BUILT_IN_POWL)
931 (define_operator_list POW10 BUILT_IN_POW10F BUILT_IN_POW10 BUILT_IN_POW10L)
932 (define_operator_list SQRT BUILT_IN_SQRTF BUILT_IN_SQRT BUILT_IN_SQRTL)
933 (define_operator_list CBRT BUILT_IN_CBRTF BUILT_IN_CBRT BUILT_IN_CBRTL)
934
935
936 /* fold_builtin_logarithm */
937 (if (flag_unsafe_math_optimizations)
938 /* Special case, optimize logN(expN(x)) = x. */
939 (for logs (LOG LOG2 LOG10)
940 exps (EXP EXP2 EXP10)
941 (simplify
942 (logs (exps @0))
943 @0))
944 /* Optimize logN(func()) for various exponential functions. We
945 want to determine the value "x" and the power "exponent" in
946 order to transform logN(x**exponent) into exponent*logN(x). */
947 (for logs (LOG LOG LOG LOG
948 LOG2 LOG2 LOG2 LOG2
949 LOG10 LOG10 LOG10 LOG10)
950 exps (EXP EXP2 EXP10 POW10)
951 (simplify
952 (logs (exps @0))
953 (with {
954 tree x;
955 switch (exps)
956 {
957 CASE_FLT_FN (BUILT_IN_EXP):
958 /* Prepare to do logN(exp(exponent) -> exponent*logN(e). */
959 x = build_real (type, real_value_truncate (TYPE_MODE (type),
960 dconst_e ()));
961 break;
962 CASE_FLT_FN (BUILT_IN_EXP2):
963 /* Prepare to do logN(exp2(exponent) -> exponent*logN(2). */
964 x = build_real (type, dconst2);
965 break;
966 CASE_FLT_FN (BUILT_IN_EXP10):
967 CASE_FLT_FN (BUILT_IN_POW10):
968 /* Prepare to do logN(exp10(exponent) -> exponent*logN(10). */
969 {
970 REAL_VALUE_TYPE dconst10;
971 real_from_integer (&dconst10, VOIDmode, 10, SIGNED);
972 x = build_real (type, dconst10);
973 }
974 break;
975 }
976 }
977 (mult (logs { x; }) @0))))
978 (for logs (LOG LOG
979 LOG2 LOG2
980 LOG10 LOG10)
981 exps (SQRT CBRT)
982 (simplify
983 (logs (exps @0))
984 (with {
985 tree x;
986 switch (exps)
987 {
988 CASE_FLT_FN (BUILT_IN_SQRT):
989 /* Prepare to do logN(sqrt(x) -> 0.5*logN(x). */
990 x = build_real (type, dconsthalf);
991 break;
992 CASE_FLT_FN (BUILT_IN_CBRT):
993 /* Prepare to do logN(cbrt(x) -> (1/3)*logN(x). */
994 x = build_real (type, real_value_truncate (TYPE_MODE (type),
995 dconst_third ()));
996 break;
997 }
998 }
999 (mult { x; } (logs @0)))))
1000 /* logN(pow(x,exponent) -> exponent*logN(x). */
1001 (for logs (LOG LOG2 LOG10)
1002 pows (POW)
1003 (simplify
1004 (logs (pows @0 @1))
1005 (mult @1 (logs @0)))))
1006