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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/96271] New: Failure to optimize memcmp of doubles to avoid going through memory Date: Tue, 21 Jul 2020 16:41:40 +0000 [thread overview] Message-ID: <bug-96271-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96271 Bug ID: 96271 Summary: Failure to optimize memcmp of doubles to avoid going through memory Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: gabravier at gmail dot com Target Milestone: --- bool f(double a, double b) { return memcmp(&a, &b, sizeof(double)) == 0; } With -O3, LLVM outputs this : f(double, double): movq rax, xmm0 movq rcx, xmm1 cmp rax, rcx sete al ret GCC outputs this: f(double, double): movsd QWORD PTR [rsp-8], xmm0 movsd QWORD PTR [rsp-16], xmm1 mov rax, QWORD PTR [rsp-16] cmp QWORD PTR [rsp-8], rax sete al ret
next reply other threads:[~2020-07-21 16:41 UTC|newest] Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-07-21 16:41 gabravier at gmail dot com [this message] 2020-07-21 18:49 ` [Bug target/96271] " pinskia at gcc dot gnu.org 2020-07-21 22:13 ` gabravier at gmail dot com 2020-07-22 7:23 ` crazylht at gmail dot com 2020-07-22 7:59 ` [Bug tree-optimization/96271] " rguenth at gcc dot gnu.org 2021-01-15 14:26 ` jakub at gcc dot gnu.org 2021-01-16 8:20 ` cvs-commit at gcc dot gnu.org 2021-01-16 8:26 ` jakub at gcc dot gnu.org 2021-01-16 8:43 ` jakub at gcc dot gnu.org
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