From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7892) id C3319385842B; Mon, 1 Aug 2022 13:24:46 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C3319385842B MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Sam Feifer To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-1916] match.pd: Add new division pattern [PR104992] X-Act-Checkin: gcc X-Git-Author: Sam Feifer X-Git-Refname: refs/heads/trunk X-Git-Oldrev: 71f068a9b3332a2179dfc807cf9138f691d77461 X-Git-Newrev: 388fbbd895e72669909173c3003ae65c6483a3c2 Message-Id: <20220801132446.C3319385842B@sourceware.org> Date: Mon, 1 Aug 2022 13:24:46 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Aug 2022 13:24:46 -0000 https://gcc.gnu.org/g:388fbbd895e72669909173c3003ae65c6483a3c2 commit r13-1916-g388fbbd895e72669909173c3003ae65c6483a3c2 Author: Sam Feifer Date: Fri Jul 29 09:44:48 2022 -0400 match.pd: Add new division pattern [PR104992] This patch fixes a missed optimization in match.pd. It takes the pattern, x / y * y == x, and optimizes it to x % y == 0. This produces fewer instructions. This simplification does not happen for complex types. This patch also adds tests for the optimization rule. Bootstrapped/regtested on x86_64-pc-linux-gnu. PR tree-optimization/104992 gcc/ChangeLog: * match.pd (x / y * y == x): New simplification. gcc/testsuite/ChangeLog: * g++.dg/pr104992-1.C: New test. * gcc.dg/pr104992.c: New test. Diff: --- gcc/match.pd | 6 +++++ gcc/testsuite/g++.dg/pr104992-1.C | 30 +++++++++++++++++++++ gcc/testsuite/gcc.dg/pr104992.c | 57 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+) diff --git a/gcc/match.pd b/gcc/match.pd index 330c1db0c8e..562138a8034 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -3982,6 +3982,12 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (plus:c (mult:c (div @0 @1) @1) (mod @0 @1)) @0)) +/* x / y * y == x -> x % y == 0. */ +(simplify + (eq:c (mult:c (trunc_div:s @0 @1) @1) @0) + (if (TREE_CODE (TREE_TYPE (@0)) != COMPLEX_TYPE) + (eq (trunc_mod @0 @1) { build_zero_cst (TREE_TYPE (@0)); }))) + /* ((X /[ex] A) +- B) * A --> X +- A * B. */ (for op (plus minus) (simplify diff --git a/gcc/testsuite/g++.dg/pr104992-1.C b/gcc/testsuite/g++.dg/pr104992-1.C new file mode 100644 index 00000000000..f5696b245ac --- /dev/null +++ b/gcc/testsuite/g++.dg/pr104992-1.C @@ -0,0 +1,30 @@ +/* PR tree-optimization/104992 */ +/* { dg-do run } */ +/* { dg-options "-O2"} */ + +#include "../gcc.dg/pr104992.c" + +int main () { + + /* Should be true. */ + if (!foo(6, 3) + || !bar(12, 2) + || !baz(34, 17) + || !qux(50, 10) + || !fred(16, 8) + || !baz(-9, 3) + || !baz(9, -3) + || !baz(-9, -3) + ) { + __builtin_abort(); + } + + /* Should be false. */ + if (foo(5, 30) + || bar(72, 27) + || baz(42, 15)) { + __builtin_abort(); + } + + return 0; +} diff --git a/gcc/testsuite/gcc.dg/pr104992.c b/gcc/testsuite/gcc.dg/pr104992.c new file mode 100644 index 00000000000..b9d91a13ad8 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr104992.c @@ -0,0 +1,57 @@ +/* PR tree-optimization/104992 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +#define vector __attribute__((vector_size(4*sizeof(int)))) + +/* Form from PR. */ +__attribute__((noipa)) unsigned foo(unsigned x, unsigned y) +{ + return x / y * y == x; +} + +__attribute__((noipa)) unsigned bar(unsigned x, unsigned y) { + return x == x / y * y; +} + +/* Signed test case. */ +__attribute__((noipa)) unsigned baz (int x, int y) { + return x / y * y == x; +} + +/* Changed order. */ +__attribute__((noipa)) unsigned qux (unsigned x, unsigned y) { + return y * (x / y) == x; +} + +/* Test for forward propogation. */ +__attribute__((noipa)) unsigned corge(unsigned x, unsigned y) { + int z = x / y; + int q = z * y; + return q == x; +} + +/* Test vector case. */ +__attribute__((noipa)) vector int thud(vector int x, vector int y) { + return x / y * y == x; +} + +/* Complex type should not simplify because mod is different. */ +__attribute__((noipa)) int goo(_Complex int x, _Complex int y) +{ + _Complex int z = x / y; + _Complex int q = z * y; + return q == x; +} + +/* Wrong order. */ +__attribute__((noipa)) unsigned fred (unsigned x, unsigned y) { + return y * x / y == x; +} + +/* Wrong pattern. */ +__attribute__((noipa)) unsigned waldo (unsigned x, unsigned y, unsigned z) { + return x / y * z == x; +} + +/* { dg-final {scan-tree-dump-times " % " 9 "optimized" } } */