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| author | Jakub Jelinek <jakub@redhat.com> | 2020-12-15 22:43:46 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-12-15 22:43:46 +0100 |
| commit | d41b097350d3c5d03824ea19520cd3b4430c9e62 (patch) | |
| tree | e0b58803d667032af0289c111ccca2f7b02166bb /gcc/match.pd | |
| parent | 36c9a3fe3f3c200ad3937d00d339b7269cf07adb (diff) | |
| download | gcc-d41b097350d3c5d03824ea19520cd3b4430c9e62.zip gcc-d41b097350d3c5d03824ea19520cd3b4430c9e62.tar.gz gcc-d41b097350d3c5d03824ea19520cd3b4430c9e62.tar.bz2 | |
match.pd: Optimize X / bool_range_Y to X [PR96094]
When the divisor is bool or has [0, 1] range, as division by
0 is UB, the only remaining option in valid programs is division by 1,
so we can optimize X / bool_range_Y into X.
2020-12-15 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/96094
* match.pd (X / bool_range_Y -> X): New simplification.
* gcc.dg/tree-ssa/pr96094.c: New test.
Diffstat (limited to 'gcc/match.pd')
| -rw-r--r-- | gcc/match.pd | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 8f3edfa..c7ee57d 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -348,11 +348,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* But not for 0 / 0 so that we can get the proper warnings and errors. */ (if (!integer_zerop (@1)) @0)) - /* X / -1 is -X. */ + /* X / -1 is -X. */ (simplify - (div @0 integer_minus_onep@1) - (if (!TYPE_UNSIGNED (type)) - (negate @0))) + (div @0 integer_minus_onep@1) + (if (!TYPE_UNSIGNED (type)) + (negate @0))) + /* X / bool_range_Y is X. */ + (simplify + (div @0 SSA_NAME@1) + (if (INTEGRAL_TYPE_P (type) && ssa_name_has_boolean_range (@1)) + @0)) /* X / X is one. */ (simplify (div @0 @0) |