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From: "piotrsiupa at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/90693] Missing popcount simplifications Date: Mon, 01 Jan 2024 12:41:57 +0000 [thread overview] Message-ID: <bug-90693-4-3fJVNLnAFx@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-90693-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90693 Piotr Siupa <piotrsiupa at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |piotrsiupa at gmail dot com --- Comment #8 from Piotr Siupa <piotrsiupa at gmail dot com> --- I did a benchmark and (x & (x-1)) == 0 and it seems to be about 2x as fast as the currently generated code (at least on my AMD64 processor). Maybe it should be used if x is guaranteed to not be zero, e.g. if (x == 0) std::unreachable().
next prev parent reply other threads:[~2024-01-01 12:42 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <bug-90693-4@http.gcc.gnu.org/bugzilla/> 2021-08-10 23:15 ` pinskia at gcc dot gnu.org 2023-11-20 9:04 ` cvs-commit at gcc dot gnu.org 2023-11-20 9:04 ` cvs-commit at gcc dot gnu.org 2023-11-20 14:10 ` wilco at gcc dot gnu.org 2023-11-20 17:01 ` jakub at gcc dot gnu.org 2024-01-01 12:41 ` piotrsiupa at gmail dot com [this message] 2024-01-03 15:34 ` jakub at gcc dot gnu.org 2024-01-05 10:17 ` cvs-commit at gcc dot gnu.org 2024-01-07 12:56 ` piotrsiupa at gmail dot com 2024-03-04 7:42 ` pinskia at gcc dot gnu.org 2024-03-04 16:41 ` pinskia at gcc dot gnu.org 2024-03-04 22:55 ` pinskia at gcc dot gnu.org
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