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From: "guihaoc at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/95737] PPC: Unnecessary extsw after negative less than Date: Thu, 06 Jan 2022 05:39:31 +0000 [thread overview] Message-ID: <bug-95737-4-iyYq14tYSJ@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-95737-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95737 HaoChen Gui <guihaoc at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |guihaoc at gcc dot gnu.org --- Comment #6 from HaoChen Gui <guihaoc at gcc dot gnu.org> --- //source code unsigned long long negativeLessThan(unsigned long long a, unsigned long long b) { return -(a < b); } //P8 with -O2 subfc 4,4,3 subfe 3,3,3 extsw 3,3 //P9 with -O2 li 10,0 li 9,1 cmpld 0,3,4 isel 3,9,10,0 neg 3,3 Seems cmp+isel on P9 is sub-optimal.
next prev parent reply other threads:[~2022-01-06 5:39 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-18 8:10 [Bug target/95737] New: " jens.seifert at de dot ibm.com 2020-06-19 16:40 ` [Bug target/95737] " wschmidt at gcc dot gnu.org 2020-06-19 16:42 ` wschmidt at gcc dot gnu.org 2020-06-19 17:43 ` jens.seifert at de dot ibm.com 2020-06-21 15:35 ` wschmidt at linux dot ibm.com 2020-06-21 16:30 ` segher at gcc dot gnu.org 2022-01-06 5:39 ` guihaoc at gcc dot gnu.org [this message] 2022-01-13 12:19 ` segher at gcc dot gnu.org 2022-01-13 16:34 ` segher at gcc dot gnu.org 2022-01-14 9:16 ` guihaoc at gcc dot gnu.org 2022-05-18 5:24 ` cvs-commit at gcc dot gnu.org 2022-07-29 2:52 ` guihaoc at gcc dot gnu.org
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