| Message ID | 20201231093434.GD3788@tucnak |
|---|---|
| State | New |
| Headers | show |
| Series | match.pd: Add (-(X < 0) | 1) * X -> abs (X) etc. simplifications [PR94785] | expand |
On December 31, 2020 10:34:34 AM GMT+01:00, Jakub Jelinek <jakub@redhat.com> wrote: >Hi! > >The following patch adds two simplifications to recognize idioms >for ABS_EXPR resp. ABSU_EXPR. > >Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk? Ok. Richard. >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. > >--- gcc/match.pd.jj 2020-12-15 22:43:39.254276743 +0100 >+++ gcc/match.pd 2020-12-30 12:00:00.924301784 +0100 >@@ -1374,6 +1374,22 @@ (define_operator_list COND_TERNARY > (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 >--- gcc/testsuite/gcc.dg/tree-ssa/pr94785.c.jj 2020-12-30 >12:03:45.693776141 +0100 >+++ gcc/testsuite/gcc.dg/tree-ssa/pr94785.c 2020-12-30 >12:04:26.895313170 +0100 >@@ -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; >+} > > Jakub
--- gcc/match.pd.jj 2020-12-15 22:43:39.254276743 +0100 +++ gcc/match.pd 2020-12-30 12:00:00.924301784 +0100 @@ -1374,6 +1374,22 @@ (define_operator_list COND_TERNARY (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 --- gcc/testsuite/gcc.dg/tree-ssa/pr94785.c.jj 2020-12-30 12:03:45.693776141 +0100 +++ gcc/testsuite/gcc.dg/tree-ssa/pr94785.c 2020-12-30 12:04:26.895313170 +0100 @@ -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; +}