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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/100798] New: a?~t:t and (-(!!a))^t don't produce the same assembly code Date: Thu, 27 May 2021 10:39:53 +0000 [thread overview] Message-ID: <bug-100798-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100798 Bug ID: 100798 Summary: a?~t:t and (-(!!a))^t don't produce the same assembly code Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: middle-end Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- While working on non GCC code, I notice these two functions don't produce the assembly code: int f(int a, int t) { return (a=='s' ? ~t : t); } int f1(int a, int t) { int t1 = -(a=='s'); return (t1 ^ t); } For aarch64, the first case produce the best, while on x86_64, I don't know which is better, sete or cmov. Note LLVM produces the same code for both, for aarch64, the csinv and sete/neg/xor for x86_64.
next reply other threads:[~2021-05-27 10:39 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-05-27 10:39 pinskia at gcc dot gnu.org [this message] 2023-05-20 2:25 ` [Bug middle-end/100798] " pinskia at gcc dot gnu.org 2023-08-07 19:04 ` pinskia at gcc dot gnu.org 2023-08-08 0:55 ` pinskia at gcc dot gnu.org 2023-08-09 19:22 ` cvs-commit at gcc dot gnu.org 2023-08-09 19:27 ` pinskia at gcc dot gnu.org
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