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.
5 Copyright (C) 2014-2015 Free Software Foundation, Inc.
6 Contributed by Richard Biener <rguenther@suse.de>
7 and Prathamesh Kulkarni <bilbotheelffriend@gmail.com>
9 This file is part of GCC.
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
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
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/>. */
26 /* Generic tree predicates we inherit. */
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
32 tree_expr_nonnegative_p)
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 (define_operator_list swapped_tcc_comparison
42 gt ge eq ne le lt unordered ordered ungt unge unlt unle uneq ltgt)
45 /* Simplifications of operations with one constant operand and
46 simplifications to constants or single values. */
48 (for op (plus pointer_plus minus bit_ior bit_xor)
53 /* 0 +p index -> (type)index */
55 (pointer_plus integer_zerop @1)
56 (non_lvalue (convert @1)))
58 /* See if ARG1 is zero and X + ARG1 reduces to X.
59 Likewise if the operands are reversed. */
61 (plus:c @0 real_zerop@1)
62 (if (fold_real_zero_addition_p (type, @1, 0))
65 /* See if ARG1 is zero and X - ARG1 reduces to X. */
67 (minus @0 real_zerop@1)
68 (if (fold_real_zero_addition_p (type, @1, 1))
72 This is unsafe for certain floats even in non-IEEE formats.
73 In IEEE, it is unsafe because it does wrong for NaNs.
74 Also note that operand_equal_p is always false if an operand
78 (if (!FLOAT_TYPE_P (type) || !HONOR_NANS (type))
79 { build_zero_cst (type); }))
82 (mult @0 integer_zerop@1)
85 /* Maybe fold x * 0 to 0. The expressions aren't the same
86 when x is NaN, since x * 0 is also NaN. Nor are they the
87 same in modes with signed zeros, since multiplying a
88 negative value by 0 gives -0, not +0. */
90 (mult @0 real_zerop@1)
91 (if (!HONOR_NANS (type) && !HONOR_SIGNED_ZEROS (element_mode (type)))
94 /* In IEEE floating point, x*1 is not equivalent to x for snans.
95 Likewise for complex arithmetic with signed zeros. */
98 (if (!HONOR_SNANS (element_mode (type))
99 && (!HONOR_SIGNED_ZEROS (element_mode (type))
100 || !COMPLEX_FLOAT_TYPE_P (type)))
103 /* Transform x * -1.0 into -x. */
105 (mult @0 real_minus_onep)
106 (if (!HONOR_SNANS (element_mode (type))
107 && (!HONOR_SIGNED_ZEROS (element_mode (type))
108 || !COMPLEX_FLOAT_TYPE_P (type)))
111 /* Make sure to preserve divisions by zero. This is the reason why
112 we don't simplify x / x to 1 or 0 / x to 0. */
113 (for op (mult trunc_div ceil_div floor_div round_div exact_div)
119 (for div (trunc_div ceil_div floor_div round_div exact_div)
121 (div @0 integer_minus_onep@1)
122 (if (!TYPE_UNSIGNED (type))
125 /* For unsigned integral types, FLOOR_DIV_EXPR is the same as
126 TRUNC_DIV_EXPR. Rewrite into the latter in this case. */
129 (if ((INTEGRAL_TYPE_P (type) || VECTOR_INTEGER_TYPE_P (type))
130 && TYPE_UNSIGNED (type))
133 /* Combine two successive divisions. Note that combining ceil_div
134 and floor_div is trickier and combining round_div even more so. */
135 (for div (trunc_div exact_div)
137 (div (div @0 INTEGER_CST@1) INTEGER_CST@2)
140 wide_int mul = wi::mul (@1, @2, TYPE_SIGN (type), &overflow_p);
143 (div @0 { wide_int_to_tree (type, mul); }))
145 && (TYPE_UNSIGNED (type)
146 || mul != wi::min_value (TYPE_PRECISION (type), SIGNED)))
147 { build_zero_cst (type); }))))
149 /* Optimize A / A to 1.0 if we don't care about
150 NaNs or Infinities. */
153 (if (FLOAT_TYPE_P (type)
154 && ! HONOR_NANS (type)
155 && ! HONOR_INFINITIES (element_mode (type)))
156 { build_one_cst (type); }))
158 /* Optimize -A / A to -1.0 if we don't care about
159 NaNs or Infinities. */
161 (rdiv:c @0 (negate @0))
162 (if (FLOAT_TYPE_P (type)
163 && ! HONOR_NANS (type)
164 && ! HONOR_INFINITIES (element_mode (type)))
165 { build_minus_one_cst (type); }))
167 /* In IEEE floating point, x/1 is not equivalent to x for snans. */
170 (if (!HONOR_SNANS (element_mode (type)))
173 /* In IEEE floating point, x/-1 is not equivalent to -x for snans. */
175 (rdiv @0 real_minus_onep)
176 (if (!HONOR_SNANS (element_mode (type)))
179 /* If ARG1 is a constant, we can convert this to a multiply by the
180 reciprocal. This does not have the same rounding properties,
181 so only do this if -freciprocal-math. We can actually
182 always safely do it if ARG1 is a power of two, but it's hard to
183 tell if it is or not in a portable manner. */
184 (for cst (REAL_CST COMPLEX_CST VECTOR_CST)
188 (if (flag_reciprocal_math
191 { tree tem = const_binop (RDIV_EXPR, type, build_one_cst (type), @1); }
193 (mult @0 { tem; } ))))
194 (if (cst != COMPLEX_CST)
195 (with { tree inverse = exact_inverse (type, @1); }
197 (mult @0 { inverse; } )))))))
199 /* Same applies to modulo operations, but fold is inconsistent here
200 and simplifies 0 % x to 0, only preserving literal 0 % 0. */
201 (for mod (ceil_mod floor_mod round_mod trunc_mod)
202 /* 0 % X is always zero. */
204 (mod integer_zerop@0 @1)
205 /* But not for 0 % 0 so that we can get the proper warnings and errors. */
206 (if (!integer_zerop (@1))
208 /* X % 1 is always zero. */
210 (mod @0 integer_onep)
211 { build_zero_cst (type); })
212 /* X % -1 is zero. */
214 (mod @0 integer_minus_onep@1)
215 (if (!TYPE_UNSIGNED (type))
216 { build_zero_cst (type); }))
217 /* (X % Y) % Y is just X % Y. */
219 (mod (mod@2 @0 @1) @1)
222 /* X % -C is the same as X % C. */
224 (trunc_mod @0 INTEGER_CST@1)
225 (if (TYPE_SIGN (type) == SIGNED
226 && !TREE_OVERFLOW (@1)
228 && !TYPE_OVERFLOW_TRAPS (type)
229 /* Avoid this transformation if C is INT_MIN, i.e. C == -C. */
230 && !sign_bit_p (@1, @1))
231 (trunc_mod @0 (negate @1))))
233 /* X % -Y is the same as X % Y. */
235 (trunc_mod @0 (convert? (negate @1)))
236 (if (!TYPE_UNSIGNED (type)
237 && !TYPE_OVERFLOW_TRAPS (type)
238 && tree_nop_conversion_p (type, TREE_TYPE (@1)))
239 (trunc_mod @0 (convert @1))))
241 /* Optimize TRUNC_MOD_EXPR by a power of two into a BIT_AND_EXPR,
242 i.e. "X % C" into "X & (C - 1)", if X and C are positive.
243 Also optimize A % (C << N) where C is a power of 2,
244 to A & ((C << N) - 1). */
245 (match (power_of_two_cand @1)
247 (match (power_of_two_cand @1)
248 (lshift INTEGER_CST@1 @2))
249 (for mod (trunc_mod floor_mod)
251 (mod @0 (convert?@3 (power_of_two_cand@1 @2)))
252 (if ((TYPE_UNSIGNED (type)
253 || tree_expr_nonnegative_p (@0))
254 && tree_nop_conversion_p (type, TREE_TYPE (@3))
255 && integer_pow2p (@2) && tree_int_cst_sgn (@2) > 0)
256 (bit_and @0 (convert (minus @1 { build_int_cst (TREE_TYPE (@1), 1); }))))))
258 /* X % Y is smaller than Y. */
261 (cmp (trunc_mod @0 @1) @1)
262 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
263 { constant_boolean_node (cmp == LT_EXPR, type); })))
266 (cmp @1 (trunc_mod @0 @1))
267 (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
268 { constant_boolean_node (cmp == GT_EXPR, type); })))
272 (bit_ior @0 integer_all_onesp@1)
277 (bit_and @0 integer_zerop@1)
283 { build_zero_cst (type); })
285 /* Canonicalize X ^ ~0 to ~X. */
287 (bit_xor @0 integer_all_onesp@1)
292 (bit_and @0 integer_all_onesp)
295 /* x & x -> x, x | x -> x */
296 (for bitop (bit_and bit_ior)
301 /* x + (x & 1) -> (x + 1) & ~1 */
303 (plus:c @0 (bit_and@2 @0 integer_onep@1))
304 (if (TREE_CODE (@2) != SSA_NAME || has_single_use (@2))
305 (bit_and (plus @0 @1) (bit_not @1))))
307 /* x & ~(x & y) -> x & ~y */
308 /* x | ~(x | y) -> x | ~y */
309 (for bitop (bit_and bit_ior)
311 (bitop:c @0 (bit_not (bitop:c@2 @0 @1)))
312 (if (TREE_CODE (@2) != SSA_NAME || has_single_use (@2))
313 (bitop @0 (bit_not @1)))))
315 /* (x | y) & ~x -> y & ~x */
316 /* (x & y) | ~x -> y | ~x */
317 (for bitop (bit_and bit_ior)
318 rbitop (bit_ior bit_and)
320 (bitop:c (rbitop:c @0 @1) (bit_not@2 @0))
327 (abs tree_expr_nonnegative_p@0)
331 /* Try to fold (type) X op CST -> (type) (X op ((type-x) CST))
333 For bitwise binary operations apply operand conversions to the
334 binary operation result instead of to the operands. This allows
335 to combine successive conversions and bitwise binary operations.
336 We combine the above two cases by using a conditional convert. */
337 (for bitop (bit_and bit_ior bit_xor)
339 (bitop (convert @0) (convert? @1))
340 (if (((TREE_CODE (@1) == INTEGER_CST
341 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
342 && int_fits_type_p (@1, TREE_TYPE (@0)))
343 || types_match (@0, @1))
344 /* ??? This transform conflicts with fold-const.c doing
345 Convert (T)(x & c) into (T)x & (T)c, if c is an integer
346 constants (if x has signed type, the sign bit cannot be set
347 in c). This folds extension into the BIT_AND_EXPR.
348 Restrict it to GIMPLE to avoid endless recursions. */
349 && (bitop != BIT_AND_EXPR || GIMPLE)
350 && (/* That's a good idea if the conversion widens the operand, thus
351 after hoisting the conversion the operation will be narrower. */
352 TYPE_PRECISION (TREE_TYPE (@0)) < TYPE_PRECISION (type)
353 /* It's also a good idea if the conversion is to a non-integer
355 || GET_MODE_CLASS (TYPE_MODE (type)) != MODE_INT
356 /* Or if the precision of TO is not the same as the precision
358 || TYPE_PRECISION (type) != GET_MODE_PRECISION (TYPE_MODE (type))))
359 (convert (bitop @0 (convert @1))))))
361 /* Simplify (A & B) OP0 (C & B) to (A OP0 C) & B. */
362 (for bitop (bit_and bit_ior bit_xor)
364 (bitop (bit_and:c @0 @1) (bit_and @2 @1))
365 (bit_and (bitop @0 @2) @1)))
367 /* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
369 (bit_and (bit_ior @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
370 (bit_ior (bit_and @0 @2) (bit_and @1 @2)))
372 /* Combine successive equal operations with constants. */
373 (for bitop (bit_and bit_ior bit_xor)
375 (bitop (bitop @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
376 (bitop @0 (bitop @1 @2))))
378 /* Try simple folding for X op !X, and X op X with the help
379 of the truth_valued_p and logical_inverted_value predicates. */
380 (match truth_valued_p
382 (if (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1)))
383 (for op (tcc_comparison truth_and truth_andif truth_or truth_orif truth_xor)
384 (match truth_valued_p
386 (match truth_valued_p
389 (match (logical_inverted_value @0)
390 (bit_not truth_valued_p@0))
391 (match (logical_inverted_value @0)
392 (eq @0 integer_zerop))
393 (match (logical_inverted_value @0)
394 (ne truth_valued_p@0 integer_truep))
395 (match (logical_inverted_value @0)
396 (bit_xor truth_valued_p@0 integer_truep))
400 (bit_and:c @0 (logical_inverted_value @0))
401 { build_zero_cst (type); })
402 /* X | !X and X ^ !X -> 1, , if X is truth-valued. */
403 (for op (bit_ior bit_xor)
405 (op:c truth_valued_p@0 (logical_inverted_value @0))
406 { constant_boolean_node (true, type); }))
408 (for bitop (bit_and bit_ior)
409 rbitop (bit_ior bit_and)
410 /* (x | y) & x -> x */
411 /* (x & y) | x -> x */
413 (bitop:c (rbitop:c @0 @1) @0)
415 /* (~x | y) & x -> x & y */
416 /* (~x & y) | x -> x | y */
418 (bitop:c (rbitop:c (bit_not @0) @1) @0)
421 /* If arg1 and arg2 are booleans (or any single bit type)
422 then try to simplify:
429 But only do this if our result feeds into a comparison as
430 this transformation is not always a win, particularly on
431 targets with and-not instructions.
432 -> simplify_bitwise_binary_boolean */
434 (ne (bit_and:c (bit_not @0) @1) integer_zerop)
435 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
436 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
439 (ne (bit_ior:c (bit_not @0) @1) integer_zerop)
440 (if (INTEGRAL_TYPE_P (TREE_TYPE (@1))
441 && TYPE_PRECISION (TREE_TYPE (@1)) == 1)
446 (bit_not (bit_not @0))
449 /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
451 (bit_ior:c (bit_and:c@3 @0 (bit_not @2)) (bit_and:c@4 @1 @2))
452 (if ((TREE_CODE (@3) != SSA_NAME || has_single_use (@3))
453 && (TREE_CODE (@4) != SSA_NAME || has_single_use (@4)))
454 (bit_xor (bit_and (bit_xor @0 @1) @2) @0)))
457 /* Associate (p +p off1) +p off2 as (p +p (off1 + off2)). */
459 (pointer_plus (pointer_plus@2 @0 @1) @3)
460 (if (TREE_CODE (@2) != SSA_NAME || has_single_use (@2))
461 (pointer_plus @0 (plus @1 @3))))
467 tem4 = (unsigned long) tem3;
472 (pointer_plus @0 (convert?@2 (minus@3 (convert @1) (convert @0))))
473 /* Conditionally look through a sign-changing conversion. */
474 (if (TYPE_PRECISION (TREE_TYPE (@2)) == TYPE_PRECISION (TREE_TYPE (@3))
475 && ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@1)))
476 || (GENERIC && type == TREE_TYPE (@1))))
480 tem = (sizetype) ptr;
484 and produce the simpler and easier to analyze with respect to alignment
485 ... = ptr & ~algn; */
487 (pointer_plus @0 (negate (bit_and (convert @0) INTEGER_CST@1)))
488 (with { tree algn = wide_int_to_tree (TREE_TYPE (@0), wi::bit_not (@1)); }
489 (bit_and @0 { algn; })))
492 /* We can't reassociate at all for saturating types. */
493 (if (!TYPE_SATURATING (type))
495 /* Contract negates. */
496 /* A + (-B) -> A - B */
498 (plus:c (convert1? @0) (convert2? (negate @1)))
499 /* Apply STRIP_NOPS on @0 and the negate. */
500 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
501 && tree_nop_conversion_p (type, TREE_TYPE (@1))
502 && !TYPE_OVERFLOW_SANITIZED (type))
503 (minus (convert @0) (convert @1))))
504 /* A - (-B) -> A + B */
506 (minus (convert1? @0) (convert2? (negate @1)))
507 (if (tree_nop_conversion_p (type, TREE_TYPE (@0))
508 && tree_nop_conversion_p (type, TREE_TYPE (@1))
509 && !TYPE_OVERFLOW_SANITIZED (type))
510 (plus (convert @0) (convert @1))))
513 (negate (convert? (negate @1)))
514 (if (tree_nop_conversion_p (type, TREE_TYPE (@1))
515 && !TYPE_OVERFLOW_SANITIZED (type))
518 /* We can't reassociate floating-point or fixed-point plus or minus
519 because of saturation to +-Inf. */
520 (if (!FLOAT_TYPE_P (type) && !FIXED_POINT_TYPE_P (type))
522 /* Match patterns that allow contracting a plus-minus pair
523 irrespective of overflow issues. */
524 /* (A +- B) - A -> +- B */
525 /* (A +- B) -+ B -> A */
526 /* A - (A +- B) -> -+ B */
527 /* A +- (B -+ A) -> +- B */
529 (minus (plus:c @0 @1) @0)
532 (minus (minus @0 @1) @0)
535 (plus:c (minus @0 @1) @1)
538 (minus @0 (plus:c @0 @1))
541 (minus @0 (minus @0 @1))
544 /* (A +- CST) +- CST -> A + CST */
545 (for outer_op (plus minus)
546 (for inner_op (plus minus)
548 (outer_op (inner_op @0 CONSTANT_CLASS_P@1) CONSTANT_CLASS_P@2)
549 /* If the constant operation overflows we cannot do the transform
550 as we would introduce undefined overflow, for example
551 with (a - 1) + INT_MIN. */
552 (with { tree cst = fold_binary (outer_op == inner_op
553 ? PLUS_EXPR : MINUS_EXPR, type, @1, @2); }
554 (if (cst && !TREE_OVERFLOW (cst))
555 (inner_op @0 { cst; } ))))))
557 /* (CST - A) +- CST -> CST - A */
558 (for outer_op (plus minus)
560 (outer_op (minus CONSTANT_CLASS_P@1 @0) CONSTANT_CLASS_P@2)
561 (with { tree cst = fold_binary (outer_op, type, @1, @2); }
562 (if (cst && !TREE_OVERFLOW (cst))
563 (minus { cst; } @0)))))
567 (plus:c (bit_not @0) @0)
568 (if (!TYPE_OVERFLOW_TRAPS (type))
569 { build_all_ones_cst (type); }))
573 (plus (convert? (bit_not @0)) integer_each_onep)
574 (if (tree_nop_conversion_p (type, TREE_TYPE (@0)))
575 (negate (convert @0))))
579 (minus (convert? (negate @0)) integer_each_onep)
580 (if (!TYPE_OVERFLOW_TRAPS (type)
581 && tree_nop_conversion_p (type, TREE_TYPE (@0)))
582 (bit_not (convert @0))))
586 (minus integer_all_onesp @0)
589 /* (T)(P + A) - (T)P -> (T) A */
590 (for add (plus pointer_plus)
592 (minus (convert (add @0 @1))
594 (if (element_precision (type) <= element_precision (TREE_TYPE (@1))
595 /* For integer types, if A has a smaller type
596 than T the result depends on the possible
598 E.g. T=size_t, A=(unsigned)429497295, P>0.
599 However, if an overflow in P + A would cause
600 undefined behavior, we can assume that there
602 || (INTEGRAL_TYPE_P (TREE_TYPE (@0))
603 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0)))
604 /* For pointer types, if the conversion of A to the
605 final type requires a sign- or zero-extension,
606 then we have to punt - it is not defined which
608 || (POINTER_TYPE_P (TREE_TYPE (@0))
609 && TREE_CODE (@1) == INTEGER_CST
610 && tree_int_cst_sign_bit (@1) == 0))
614 /* Simplifications of MIN_EXPR and MAX_EXPR. */
616 (for minmax (min max)
622 (if (INTEGRAL_TYPE_P (type)
623 && TYPE_MIN_VALUE (type)
624 && operand_equal_p (@1, TYPE_MIN_VALUE (type), OEP_ONLY_CONST))
628 (if (INTEGRAL_TYPE_P (type)
629 && TYPE_MAX_VALUE (type)
630 && operand_equal_p (@1, TYPE_MAX_VALUE (type), OEP_ONLY_CONST))
634 /* Simplifications of shift and rotates. */
636 (for rotate (lrotate rrotate)
638 (rotate integer_all_onesp@0 @1)
641 /* Optimize -1 >> x for arithmetic right shifts. */
643 (rshift integer_all_onesp@0 @1)
644 (if (!TYPE_UNSIGNED (type)
645 && tree_expr_nonnegative_p (@1))
648 (for shiftrotate (lrotate rrotate lshift rshift)
650 (shiftrotate @0 integer_zerop)
653 (shiftrotate integer_zerop@0 @1)
655 /* Prefer vector1 << scalar to vector1 << vector2
656 if vector2 is uniform. */
657 (for vec (VECTOR_CST CONSTRUCTOR)
659 (shiftrotate @0 vec@1)
660 (with { tree tem = uniform_vector_p (@1); }
662 (shiftrotate @0 { tem; }))))))
664 /* Rewrite an LROTATE_EXPR by a constant into an
665 RROTATE_EXPR by a new constant. */
667 (lrotate @0 INTEGER_CST@1)
668 (rrotate @0 { fold_binary (MINUS_EXPR, TREE_TYPE (@1),
669 build_int_cst (TREE_TYPE (@1),
670 element_precision (type)), @1); }))
672 /* ((1 << A) & 1) != 0 -> A == 0
673 ((1 << A) & 1) == 0 -> A != 0 */
677 (cmp (bit_and (lshift integer_onep @0) integer_onep) integer_zerop)
678 (icmp @0 { build_zero_cst (TREE_TYPE (@0)); })))
680 /* (CST1 << A) == CST2 -> A == ctz (CST2) - ctz (CST1)
681 (CST1 << A) != CST2 -> A != ctz (CST2) - ctz (CST1)
685 (cmp (lshift INTEGER_CST@0 @1) INTEGER_CST@2)
686 (with { int cand = wi::ctz (@2) - wi::ctz (@0); }
688 || (!integer_zerop (@2)
689 && wi::ne_p (wi::lshift (@0, cand), @2)))
690 { constant_boolean_node (cmp == NE_EXPR, type); })
691 (if (!integer_zerop (@2)
692 && wi::eq_p (wi::lshift (@0, cand), @2))
693 (cmp @1 { build_int_cst (TREE_TYPE (@1), cand); })))))
695 /* Simplifications of conversions. */
697 /* Basic strip-useless-type-conversions / strip_nops. */
698 (for cvt (convert view_convert float fix_trunc)
701 (if ((GIMPLE && useless_type_conversion_p (type, TREE_TYPE (@0)))
702 || (GENERIC && type == TREE_TYPE (@0)))
705 /* Contract view-conversions. */
707 (view_convert (view_convert @0))
710 /* For integral conversions with the same precision or pointer
711 conversions use a NOP_EXPR instead. */
714 (if ((INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
715 && (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
716 && TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (@0)))
719 /* Strip inner integral conversions that do not change precision or size. */
721 (view_convert (convert@0 @1))
722 (if ((INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
723 && (INTEGRAL_TYPE_P (TREE_TYPE (@1)) || POINTER_TYPE_P (TREE_TYPE (@1)))
724 && (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1)))
725 && (TYPE_SIZE (TREE_TYPE (@0)) == TYPE_SIZE (TREE_TYPE (@1))))
728 /* Re-association barriers around constants and other re-association
729 barriers can be removed. */
731 (paren CONSTANT_CLASS_P@0)
737 /* Handle cases of two conversions in a row. */
738 (for ocvt (convert float fix_trunc)
739 (for icvt (convert float)
744 tree inside_type = TREE_TYPE (@0);
745 tree inter_type = TREE_TYPE (@1);
746 int inside_int = INTEGRAL_TYPE_P (inside_type);
747 int inside_ptr = POINTER_TYPE_P (inside_type);
748 int inside_float = FLOAT_TYPE_P (inside_type);
749 int inside_vec = VECTOR_TYPE_P (inside_type);
750 unsigned int inside_prec = TYPE_PRECISION (inside_type);
751 int inside_unsignedp = TYPE_UNSIGNED (inside_type);
752 int inter_int = INTEGRAL_TYPE_P (inter_type);
753 int inter_ptr = POINTER_TYPE_P (inter_type);
754 int inter_float = FLOAT_TYPE_P (inter_type);
755 int inter_vec = VECTOR_TYPE_P (inter_type);
756 unsigned int inter_prec = TYPE_PRECISION (inter_type);
757 int inter_unsignedp = TYPE_UNSIGNED (inter_type);
758 int final_int = INTEGRAL_TYPE_P (type);
759 int final_ptr = POINTER_TYPE_P (type);
760 int final_float = FLOAT_TYPE_P (type);
761 int final_vec = VECTOR_TYPE_P (type);
762 unsigned int final_prec = TYPE_PRECISION (type);
763 int final_unsignedp = TYPE_UNSIGNED (type);
765 /* In addition to the cases of two conversions in a row
766 handled below, if we are converting something to its own
767 type via an object of identical or wider precision, neither
768 conversion is needed. */
769 (if (((GIMPLE && useless_type_conversion_p (type, inside_type))
771 && TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (inside_type)))
772 && (((inter_int || inter_ptr) && final_int)
773 || (inter_float && final_float))
774 && inter_prec >= final_prec)
777 /* Likewise, if the intermediate and initial types are either both
778 float or both integer, we don't need the middle conversion if the
779 former is wider than the latter and doesn't change the signedness
780 (for integers). Avoid this if the final type is a pointer since
781 then we sometimes need the middle conversion. Likewise if the
782 final type has a precision not equal to the size of its mode. */
783 (if (((inter_int && inside_int) || (inter_float && inside_float))
784 && (final_int || final_float)
785 && inter_prec >= inside_prec
786 && (inter_float || inter_unsignedp == inside_unsignedp)
787 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
788 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
791 /* If we have a sign-extension of a zero-extended value, we can
792 replace that by a single zero-extension. Likewise if the
793 final conversion does not change precision we can drop the
794 intermediate conversion. */
795 (if (inside_int && inter_int && final_int
796 && ((inside_prec < inter_prec && inter_prec < final_prec
797 && inside_unsignedp && !inter_unsignedp)
798 || final_prec == inter_prec))
801 /* Two conversions in a row are not needed unless:
802 - some conversion is floating-point (overstrict for now), or
803 - some conversion is a vector (overstrict for now), or
804 - the intermediate type is narrower than both initial and
806 - the intermediate type and innermost type differ in signedness,
807 and the outermost type is wider than the intermediate, or
808 - the initial type is a pointer type and the precisions of the
809 intermediate and final types differ, or
810 - the final type is a pointer type and the precisions of the
811 initial and intermediate types differ. */
812 (if (! inside_float && ! inter_float && ! final_float
813 && ! inside_vec && ! inter_vec && ! final_vec
814 && (inter_prec >= inside_prec || inter_prec >= final_prec)
815 && ! (inside_int && inter_int
816 && inter_unsignedp != inside_unsignedp
817 && inter_prec < final_prec)
818 && ((inter_unsignedp && inter_prec > inside_prec)
819 == (final_unsignedp && final_prec > inter_prec))
820 && ! (inside_ptr && inter_prec != final_prec)
821 && ! (final_ptr && inside_prec != inter_prec)
822 && ! (final_prec != GET_MODE_PRECISION (TYPE_MODE (type))
823 && TYPE_MODE (type) == TYPE_MODE (inter_type)))
826 /* A truncation to an unsigned type (a zero-extension) should be
827 canonicalized as bitwise and of a mask. */
828 (if (final_int && inter_int && inside_int
829 && final_prec == inside_prec
830 && final_prec > inter_prec
832 (convert (bit_and @0 { wide_int_to_tree
834 wi::mask (inter_prec, false,
835 TYPE_PRECISION (inside_type))); })))
837 /* If we are converting an integer to a floating-point that can
838 represent it exactly and back to an integer, we can skip the
839 floating-point conversion. */
840 (if (GIMPLE /* PR66211 */
841 && inside_int && inter_float && final_int &&
842 (unsigned) significand_size (TYPE_MODE (inter_type))
843 >= inside_prec - !inside_unsignedp)
846 /* If we have a narrowing conversion to an integral type that is fed by a
847 BIT_AND_EXPR, we might be able to remove the BIT_AND_EXPR if it merely
848 masks off bits outside the final type (and nothing else). */
850 (convert (bit_and @0 INTEGER_CST@1))
851 (if (INTEGRAL_TYPE_P (type)
852 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
853 && TYPE_PRECISION (type) <= TYPE_PRECISION (TREE_TYPE (@0))
854 && operand_equal_p (@1, build_low_bits_mask (TREE_TYPE (@1),
855 TYPE_PRECISION (type)), 0))
859 /* (X /[ex] A) * A -> X. */
861 (mult (convert? (exact_div @0 @1)) @1)
862 /* Look through a sign-changing conversion. */
865 /* Canonicalization of binary operations. */
867 /* Convert X + -C into X - C. */
870 (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
871 (with { tree tem = fold_unary (NEGATE_EXPR, type, @1); }
872 (if (!TREE_OVERFLOW (tem) || !flag_trapping_math)
873 (minus @0 { tem; })))))
875 /* Convert x+x into x*2.0. */
878 (if (SCALAR_FLOAT_TYPE_P (type))
879 (mult @0 { build_real (type, dconst2); })))
882 (minus integer_zerop @1)
885 /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
886 ARG0 is zero and X + ARG0 reduces to X, since that would mean
887 (-ARG1 + ARG0) reduces to -ARG1. */
889 (minus real_zerop@0 @1)
890 (if (fold_real_zero_addition_p (type, @0, 0))
893 /* Transform x * -1 into -x. */
895 (mult @0 integer_minus_onep)
898 /* COMPLEX_EXPR and REALPART/IMAGPART_EXPR cancellations. */
900 (complex (realpart @0) (imagpart @0))
903 (realpart (complex @0 @1))
906 (imagpart (complex @0 @1))
910 /* BSWAP simplifications, transforms checked by gcc.dg/builtin-bswap-8.c. */
911 (for bswap (BUILT_IN_BSWAP16 BUILT_IN_BSWAP32 BUILT_IN_BSWAP64)
916 (bswap (bit_not (bswap @0)))
918 (for bitop (bit_xor bit_ior bit_and)
920 (bswap (bitop:c (bswap @0) @1))
921 (bitop @0 (bswap @1)))))
924 /* Combine COND_EXPRs and VEC_COND_EXPRs. */
926 /* Simplify constant conditions.
927 Only optimize constant conditions when the selected branch
928 has the same type as the COND_EXPR. This avoids optimizing
929 away "c ? x : throw", where the throw has a void type.
930 Note that we cannot throw away the fold-const.c variant nor
931 this one as we depend on doing this transform before possibly
932 A ? B : B -> B triggers and the fold-const.c one can optimize
933 0 ? A : B to B even if A has side-effects. Something
934 genmatch cannot handle. */
936 (cond INTEGER_CST@0 @1 @2)
937 (if (integer_zerop (@0)
938 && (!VOID_TYPE_P (TREE_TYPE (@2))
939 || VOID_TYPE_P (type)))
941 (if (!integer_zerop (@0)
942 && (!VOID_TYPE_P (TREE_TYPE (@1))
943 || VOID_TYPE_P (type)))
946 (vec_cond VECTOR_CST@0 @1 @2)
947 (if (integer_all_onesp (@0))
949 (if (integer_zerop (@0))
952 (for cnd (cond vec_cond)
953 /* A ? B : (A ? X : C) -> A ? B : C. */
955 (cnd @0 (cnd @0 @1 @2) @3)
958 (cnd @0 @1 (cnd @0 @2 @3))
961 /* A ? B : B -> B. */
966 /* !A ? B : C -> A ? C : B. */
968 (cnd (logical_inverted_value truth_valued_p@0) @1 @2)
972 /* Simplifications of comparisons. */
974 /* We can simplify a logical negation of a comparison to the
975 inverted comparison. As we cannot compute an expression
976 operator using invert_tree_comparison we have to simulate
977 that with expression code iteration. */
978 (for cmp (tcc_comparison)
979 icmp (inverted_tcc_comparison)
980 ncmp (inverted_tcc_comparison_with_nans)
981 /* Ideally we'd like to combine the following two patterns
982 and handle some more cases by using
983 (logical_inverted_value (cmp @0 @1))
984 here but for that genmatch would need to "inline" that.
985 For now implement what forward_propagate_comparison did. */
987 (bit_not (cmp @0 @1))
988 (if (VECTOR_TYPE_P (type)
989 || (INTEGRAL_TYPE_P (type) && TYPE_PRECISION (type) == 1))
990 /* Comparison inversion may be impossible for trapping math,
991 invert_tree_comparison will tell us. But we can't use
992 a computed operator in the replacement tree thus we have
993 to play the trick below. */
994 (with { enum tree_code ic = invert_tree_comparison
995 (cmp, HONOR_NANS (@0)); }
1001 (bit_xor (cmp @0 @1) integer_truep)
1002 (with { enum tree_code ic = invert_tree_comparison
1003 (cmp, HONOR_NANS (@0)); }
1009 /* Unordered tests if either argument is a NaN. */
1011 (bit_ior (unordered @0 @0) (unordered @1 @1))
1012 (if (types_match (@0, @1))
1015 (bit_and (ordered @0 @0) (ordered @1 @1))
1016 (if (types_match (@0, @1))
1019 (bit_ior:c (unordered @0 @0) (unordered:c@2 @0 @1))
1022 (bit_and:c (ordered @0 @0) (ordered:c@2 @0 @1))
1025 /* -A CMP -B -> B CMP A. */
1026 (for cmp (tcc_comparison)
1027 scmp (swapped_tcc_comparison)
1029 (cmp (negate @0) (negate @1))
1030 (if (FLOAT_TYPE_P (TREE_TYPE (@0))
1031 || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
1032 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
1035 (cmp (negate @0) CONSTANT_CLASS_P@1)
1036 (if (FLOAT_TYPE_P (TREE_TYPE (@0))
1037 || (ANY_INTEGRAL_TYPE_P (TREE_TYPE (@0))
1038 && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (@0))))
1039 (with { tree tem = fold_unary (NEGATE_EXPR, TREE_TYPE (@0), @1); }
1040 (if (tem && !TREE_OVERFLOW (tem))
1041 (scmp @0 { tem; }))))))
1043 /* Simplification of math builtins. */
1045 (define_operator_list LOG BUILT_IN_LOGF BUILT_IN_LOG BUILT_IN_LOGL)
1046 (define_operator_list EXP BUILT_IN_EXPF BUILT_IN_EXP BUILT_IN_EXPL)
1047 (define_operator_list LOG2 BUILT_IN_LOG2F BUILT_IN_LOG2 BUILT_IN_LOG2L)
1048 (define_operator_list EXP2 BUILT_IN_EXP2F BUILT_IN_EXP2 BUILT_IN_EXP2L)
1049 (define_operator_list LOG10 BUILT_IN_LOG10F BUILT_IN_LOG10 BUILT_IN_LOG10L)
1050 (define_operator_list EXP10 BUILT_IN_EXP10F BUILT_IN_EXP10 BUILT_IN_EXP10L)
1051 (define_operator_list POW BUILT_IN_POWF BUILT_IN_POW BUILT_IN_POWL)
1052 (define_operator_list POW10 BUILT_IN_POW10F BUILT_IN_POW10 BUILT_IN_POW10L)
1053 (define_operator_list SQRT BUILT_IN_SQRTF BUILT_IN_SQRT BUILT_IN_SQRTL)
1054 (define_operator_list CBRT BUILT_IN_CBRTF BUILT_IN_CBRT BUILT_IN_CBRTL)
1057 /* fold_builtin_logarithm */
1058 (if (flag_unsafe_math_optimizations)
1059 /* Special case, optimize logN(expN(x)) = x. */
1060 (for logs (LOG LOG2 LOG10)
1061 exps (EXP EXP2 EXP10)
1065 /* Optimize logN(func()) for various exponential functions. We
1066 want to determine the value "x" and the power "exponent" in
1067 order to transform logN(x**exponent) into exponent*logN(x). */
1068 (for logs (LOG LOG LOG LOG
1070 LOG10 LOG10 LOG10 LOG10)
1071 exps (EXP EXP2 EXP10 POW10)
1078 CASE_FLT_FN (BUILT_IN_EXP):
1079 /* Prepare to do logN(exp(exponent) -> exponent*logN(e). */
1080 x = build_real (type, real_value_truncate (TYPE_MODE (type),
1083 CASE_FLT_FN (BUILT_IN_EXP2):
1084 /* Prepare to do logN(exp2(exponent) -> exponent*logN(2). */
1085 x = build_real (type, dconst2);
1087 CASE_FLT_FN (BUILT_IN_EXP10):
1088 CASE_FLT_FN (BUILT_IN_POW10):
1089 /* Prepare to do logN(exp10(exponent) -> exponent*logN(10). */
1091 REAL_VALUE_TYPE dconst10;
1092 real_from_integer (&dconst10, VOIDmode, 10, SIGNED);
1093 x = build_real (type, dconst10);
1098 (mult (logs { x; }) @0))))
1109 CASE_FLT_FN (BUILT_IN_SQRT):
1110 /* Prepare to do logN(sqrt(x) -> 0.5*logN(x). */
1111 x = build_real (type, dconsthalf);
1113 CASE_FLT_FN (BUILT_IN_CBRT):
1114 /* Prepare to do logN(cbrt(x) -> (1/3)*logN(x). */
1115 x = build_real (type, real_value_truncate (TYPE_MODE (type),
1120 (mult { x; } (logs @0)))))
1121 /* logN(pow(x,exponent) -> exponent*logN(x). */
1122 (for logs (LOG LOG2 LOG10)
1126 (mult @1 (logs @0)))))
1128 /* Narrowing of arithmetic and logical operations.
1130 These are conceptually similar to the transformations performed for
1131 the C/C++ front-ends by shorten_binary_op and shorten_compare. Long
1132 term we want to move all that code out of the front-ends into here. */
1134 /* If we have a narrowing conversion of an arithmetic operation where
1135 both operands are widening conversions from the same type as the outer
1136 narrowing conversion. Then convert the innermost operands to a suitable
1137 unsigned type (to avoid introducing undefined behaviour), perform the
1138 operation and convert the result to the desired type. */
1139 (for op (plus minus)
1141 (convert (op@4 (convert@2 @0) (convert@3 @1)))
1142 (if (INTEGRAL_TYPE_P (type)
1143 /* We check for type compatibility between @0 and @1 below,
1144 so there's no need to check that @1/@3 are integral types. */
1145 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
1146 && INTEGRAL_TYPE_P (TREE_TYPE (@2))
1147 /* The precision of the type of each operand must match the
1148 precision of the mode of each operand, similarly for the
1150 && (TYPE_PRECISION (TREE_TYPE (@0))
1151 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@0))))
1152 && (TYPE_PRECISION (TREE_TYPE (@1))
1153 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@1))))
1154 && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
1155 /* The inner conversion must be a widening conversion. */
1156 && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0))
1157 && types_match (@0, @1)
1158 && types_match (@0, type)
1160 (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
1161 (convert (op @0 @1)))
1162 (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
1163 (convert (op (convert:utype @0) (convert:utype @1)))))))
1165 /* This is another case of narrowing, specifically when there's an outer
1166 BIT_AND_EXPR which masks off bits outside the type of the innermost
1167 operands. Like the previous case we have to convert the operands
1168 to unsigned types to avoid introducing undefined behaviour for the
1169 arithmetic operation. */
1170 (for op (minus plus)
1172 (bit_and (op@5 (convert@2 @0) (convert@3 @1)) INTEGER_CST@4)
1173 (if (INTEGRAL_TYPE_P (type)
1174 /* We check for type compatibility between @0 and @1 below,
1175 so there's no need to check that @1/@3 are integral types. */
1176 && INTEGRAL_TYPE_P (TREE_TYPE (@0))
1177 && INTEGRAL_TYPE_P (TREE_TYPE (@2))
1178 /* The precision of the type of each operand must match the
1179 precision of the mode of each operand, similarly for the
1181 && (TYPE_PRECISION (TREE_TYPE (@0))
1182 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@0))))
1183 && (TYPE_PRECISION (TREE_TYPE (@1))
1184 == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (@1))))
1185 && TYPE_PRECISION (type) == GET_MODE_PRECISION (TYPE_MODE (type))
1186 /* The inner conversion must be a widening conversion. */
1187 && TYPE_PRECISION (TREE_TYPE (@2)) > TYPE_PRECISION (TREE_TYPE (@0))
1188 && types_match (@0, @1)
1189 && (tree_int_cst_min_precision (@4, TYPE_SIGN (TREE_TYPE (@0)))
1190 <= TYPE_PRECISION (TREE_TYPE (@0)))
1191 && (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0))
1192 || tree_int_cst_sgn (@4) >= 0)
1194 (if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (@0)))
1195 (with { tree ntype = TREE_TYPE (@0); }
1196 (convert (bit_and (op @0 @1) (convert:ntype @4)))))
1197 (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); }
1198 (convert (bit_and (op (convert:utype @0) (convert:utype @1))
1199 (convert:utype @4)))))))