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From: "llvm at rifkin dot dev" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/101754] New: Missed fold for a/b*b Date: Tue, 03 Aug 2021 14:00:06 +0000 [thread overview] Message-ID: <bug-101754-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101754 Bug ID: 101754 Summary: Missed fold for a/b*b Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: llvm at rifkin dot dev Target Milestone: --- GCC is not optimizing the following (contrived) divisibility check https://godbolt.org/z/1rEhYa8Ts. bool foo(int a, int b) { return a/b*b == a; } bool bar(int a, int b) { return a%b == 0; } If GCC can fold a/b*b into a-a%b, it will be able to optimize properly the rest of the way.
next reply other threads:[~2021-08-03 14:00 UTC|newest] Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-08-03 14:00 llvm at rifkin dot dev [this message] 2021-08-04 5:54 ` [Bug tree-optimization/101754] " rguenth at gcc dot gnu.org 2021-12-16 0:19 ` pinskia at gcc dot gnu.org
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