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| author | Jakub Jelinek <jakub@redhat.com> | 2020-12-06 10:55:12 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-12-06 10:55:12 +0100 |
| commit | 9e12b8b1819342ef7efac58cf7f4ba4294abe551 (patch) | |
| tree | e85728c3ca27665a12469a0206a08fd0869b6ff3 | |
| parent | bd0f0243869b3941a256ca0ea9c8aca141412f7e (diff) | |
| download | gcc-9e12b8b1819342ef7efac58cf7f4ba4294abe551.zip gcc-9e12b8b1819342ef7efac58cf7f4ba4294abe551.tar.gz gcc-9e12b8b1819342ef7efac58cf7f4ba4294abe551.tar.bz2 | |
match.pd: Improve conditional_replacement for x ? 0 : -1 [PR796232]
As mentioned in the PR, for boolean x we currently optimize
in phiopt x ? 0 : -1 into -(int)!x but it can be optimized as
(int) x - 1 which is one less operation both in GIMPLE and in x86 assembly.
This patch optimizes it in match.pd, by optimizing -(type)!x when
x has boolean range into (type)x - 1.
2020-12-06 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/96232
* match.pd (-(type)!A -> (type)A - 1): New optimization.
* gcc.dg/tree-ssa/pr96232-1.c: New test.
| -rw-r--r-- | gcc/match.pd | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr96232-1.c | 11 |
2 files changed, 21 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 68201ff..43bacb4 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3812,6 +3812,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (cnd (logical_inverted_value truth_valued_p@0) @1 @2) (cnd @0 @2 @1))) +/* -(type)!A -> (type)A - 1. */ +(simplify + (negate (convert?:s (logical_inverted_value:s @0))) + (if (INTEGRAL_TYPE_P (type) + && TREE_CODE (type) != BOOLEAN_TYPE + && TYPE_PRECISION (type) > 1 + && TREE_CODE (@0) == SSA_NAME + && ssa_name_has_boolean_range (@0)) + (plus (convert:type @0) { build_all_ones_cst (type); }))) + /* A + (B vcmp C ? 1 : 0) -> A - (B vcmp C ? -1 : 0), since vector comparisons return all -1 or all 0 results. */ /* ??? We could instead convert all instances of the vec_cond to negate, diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr96232-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr96232-1.c new file mode 100644 index 0000000..3170ffd --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr96232-1.c @@ -0,0 +1,11 @@ +/* PR tree-optimization/96232 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump " \\+ -1;" "optimized" } } */ +/* { dg-final { scan-tree-dump-not "~x_\[0-9]*\\\(D\\\)" "optimized" } } */ + +int +foo (_Bool x) +{ + return x ? 0 : -1; +} |