From 6d938a5d770d0e94ecd923d20006b05126659235 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 5 May 2020 11:31:43 +0200 Subject: [PATCH] match.pd: Optimize (((type)A * B) >> prec) != 0 into __imag__ .MUL_OVERFLOW [PR94914] On x86 (the only target with umulv4_optab) one can use mull; seto to check for overflow instead of performing wider multiplication and performing comparison on the high bits. 2020-05-05 Jakub Jelinek PR tree-optimization/94914 * match.pd ((((type)A * B) >> prec) != 0 to .MUL_OVERFLOW(A, B) != 0): New simplification. * gcc.target/i386/pr94914.c: New test. --- gcc/ChangeLog | 6 ++++++ gcc/match.pd | 21 +++++++++++++++++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.target/i386/pr94914.c | 17 +++++++++++++++++ 4 files changed, 49 insertions(+) create mode 100644 gcc/testsuite/gcc.target/i386/pr94914.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 8c46dcd92c3..e51c0e09722 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2020-05-05 Jakub Jelinek + + PR tree-optimization/94914 + * match.pd ((((type)A * B) >> prec) != 0 to .MUL_OVERFLOW(A, B) != 0): + New simplification. + 2020-05-05 Uroš Bizjak * config/i386/i386.md (*testqi_ext_3): Use diff --git a/gcc/match.pd b/gcc/match.pd index 9c1e23984d6..c45e94c0c6a 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -4776,6 +4776,27 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (with { tree t = TREE_TYPE (@0), cpx = build_complex_type (t); } (out (imagpart (IFN_MUL_OVERFLOW:cpx @0 @1)) { build_zero_cst (t); }))))) +/* Similarly, for unsigned operands, (((type) A * B) >> prec) != 0 where type + is at least twice as wide as type of A and B, simplify to + __builtin_mul_overflow (A, B, ). */ +(for cmp (eq ne) + (simplify + (cmp (rshift (mult:s (convert@3 @0) (convert @1)) INTEGER_CST@2) + integer_zerop) + (if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) + && INTEGRAL_TYPE_P (TREE_TYPE (@3)) + && TYPE_UNSIGNED (TREE_TYPE (@0)) + && (TYPE_PRECISION (TREE_TYPE (@3)) + >= 2 * TYPE_PRECISION (TREE_TYPE (@0))) + && tree_fits_uhwi_p (@2) + && tree_to_uhwi (@2) == TYPE_PRECISION (TREE_TYPE (@0)) + && types_match (@0, @1) + && type_has_mode_precision_p (TREE_TYPE (@0)) + && (optab_handler (umulv4_optab, TYPE_MODE (TREE_TYPE (@0))) + != CODE_FOR_nothing)) + (with { tree t = TREE_TYPE (@0), cpx = build_complex_type (t); } + (cmp (imagpart (IFN_MUL_OVERFLOW:cpx @0 @1)) { build_zero_cst (t); }))))) + /* Simplification of math builtins. These rules must all be optimizations as well as IL simplifications. If there is a possibility that the new form could be a pessimization, the rule should go in the canonicalization diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 09f89951042..2a44c70a777 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2020-05-05 Jakub Jelinek + + PR tree-optimization/94914 + * gcc.target/i386/pr94914.c: New test. + 2020-05-04 Patrick Palka PR c++/94038 diff --git a/gcc/testsuite/gcc.target/i386/pr94914.c b/gcc/testsuite/gcc.target/i386/pr94914.c new file mode 100644 index 00000000000..932bd21473d --- /dev/null +++ b/gcc/testsuite/gcc.target/i386/pr94914.c @@ -0,0 +1,17 @@ +/* PR tree-optimization/94914 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ +/* { dg-final { scan-assembler "\tseto\t" } } */ +/* { dg-final { scan-assembler "\tsetno\t" } } */ + +int +foo (unsigned int x, unsigned int y) +{ + return (((unsigned long long)x * y) >> 32) != 0; +} + +int +bar (unsigned int x, unsigned int y) +{ + return (((unsigned long long)x * y) >> 32) == 0; +} -- 2.30.2