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author | Jakub Jelinek <jakub@redhat.com> | 2020-12-31 11:08:15 +0100 |
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committer | Jakub Jelinek <jakub@redhat.com> | 2020-12-31 11:08:15 +0100 |
commit | 8f12ce2ea3be12de4f83d3c419bdb1dc5036b202 (patch) | |
tree | acdd88b6fe3f832de1cfc8febfc18dbf98a27043 /gcc | |
parent | 9e603837f7ad886df62e02ac0cd395ec17b7d587 (diff) | |
download | gcc-8f12ce2ea3be12de4f83d3c419bdb1dc5036b202.zip gcc-8f12ce2ea3be12de4f83d3c419bdb1dc5036b202.tar.gz gcc-8f12ce2ea3be12de4f83d3c419bdb1dc5036b202.tar.bz2 |
match.pd: Add (-(X < 0) | 1) * X -> abs (X) etc. simplifications [PR94785]
The following patch adds two simplifications to recognize idioms
for ABS_EXPR resp. ABSU_EXPR.
2020-12-31 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/94785
* match.pd ((-(X < 0) | 1) * X -> abs (X)): New simplification.
((-(X < 0) | 1U) * X -> absu (X)): Likewise.
* gcc.dg/tree-ssa/pr94785.c: New test.
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/match.pd | 16 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr94785.c | 36 |
2 files changed, 52 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index c7ee57d..1055292 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1374,6 +1374,22 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (absu tree_expr_nonnegative_p@0) (convert @0)) +/* Simplify (-(X < 0) | 1) * X into abs (X). */ +(simplify + (mult:c (bit_ior (negate (convert? (lt @0 integer_zerop))) integer_onep) @0) + (if (INTEGRAL_TYPE_P (type) && !TYPE_UNSIGNED (type)) + (abs @0))) + +/* Similarly (-(X < 0) | 1U) * X into absu (X). */ +(simplify + (mult:c (bit_ior (nop_convert (negate (convert? (lt @0 integer_zerop)))) + integer_onep) (nop_convert @0)) + (if (INTEGRAL_TYPE_P (type) + && TYPE_UNSIGNED (type) + && INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && !TYPE_UNSIGNED (TREE_TYPE (@0))) + (absu @0))) + /* A few cases of fold-const.c negate_expr_p predicate. */ (match negate_expr_p INTEGER_CST diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr94785.c b/gcc/testsuite/gcc.dg/tree-ssa/pr94785.c new file mode 100644 index 0000000..9239284 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr94785.c @@ -0,0 +1,36 @@ +/* PR tree-optimization/94785 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ +/* { dg-final { scan-tree-dump-times " = ABS_EXPR <v_\[0-9]*\\\(D\\\)>;" 2 "optimized" } } */ +/* { dg-final { scan-tree-dump-times " = ABSU_EXPR <v_\[0-9]*\\\(D\\\)>;" 2 "optimized" } } */ + +int +f1 (int v) +{ + return (1 | -(v < 0)) * v; +} + +unsigned +f2 (int v) +{ + return (1U | -(v < 0)) * v; +} + +int +f3 (int v) +{ + int a = v < 0; + int b = -a; + int c = 1 | b; + return c * v; +} + +unsigned +f4 (int v) +{ + int a = v < 0; + int b = -a; + unsigned c = b; + unsigned d = c | 1; + return d * v; +} |