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* [Bug c/108073] New: [rs6000] sub-optimal float member accessing on struct parameter @ 2022-12-12 12:15 guojiufu at gcc dot gnu.org 2022-12-12 12:30 ` [Bug middle-end/108073] " pinskia at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: guojiufu at gcc dot gnu.org @ 2022-12-12 12:15 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108073 Bug ID: 108073 Summary: [rs6000] sub-optimal float member accessing on struct parameter Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: guojiufu at gcc dot gnu.org Target Milestone: --- For the below code: typedef struct DF {double a[4]; long l; } DF; double __attribute__ ((noipa)) foo_df (DF arg){return arg.a[3];} At -O2, with gcc trunk(13.0), we get below sequence: std 6,-24(1) ori 2,2,0 lfd 1,-24(1) blr Actually, just one "mtvsrd 1, 6" is enough. In this case, the argument is passed through integer registers. For below code, it is similar: typedef struct SF {float a[4];short l; } SF; float foo (SF arg){return arg.a[3];} std 4,-24(1) ori 2,2,0 lfs 1,-20(1) vs. below seq seems faster. rldicr 4,4,0,31 mtvsrd 1,4 xscvspdpn 1,1 ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/108073] [rs6000] sub-optimal float member accessing on struct parameter 2022-12-12 12:15 [Bug c/108073] New: [rs6000] sub-optimal float member accessing on struct parameter guojiufu at gcc dot gnu.org @ 2022-12-12 12:30 ` pinskia at gcc dot gnu.org 2022-12-20 8:59 ` jskumari at gcc dot gnu.org 2022-12-21 6:46 ` guojiufu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2022-12-12 12:30 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108073 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |missed-optimization Severity|normal |enhancement ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/108073] [rs6000] sub-optimal float member accessing on struct parameter 2022-12-12 12:15 [Bug c/108073] New: [rs6000] sub-optimal float member accessing on struct parameter guojiufu at gcc dot gnu.org 2022-12-12 12:30 ` [Bug middle-end/108073] " pinskia at gcc dot gnu.org @ 2022-12-20 8:59 ` jskumari at gcc dot gnu.org 2022-12-21 6:46 ` guojiufu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: jskumari at gcc dot gnu.org @ 2022-12-20 8:59 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108073 Surya Kumari Jangala <jskumari at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jskumari at gcc dot gnu.org --- Comment #1 from Surya Kumari Jangala <jskumari at gcc dot gnu.org> --- Hi Jiu Fu Guo, are you working on this bug? If not, I would like to take this up. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug middle-end/108073] [rs6000] sub-optimal float member accessing on struct parameter 2022-12-12 12:15 [Bug c/108073] New: [rs6000] sub-optimal float member accessing on struct parameter guojiufu at gcc dot gnu.org 2022-12-12 12:30 ` [Bug middle-end/108073] " pinskia at gcc dot gnu.org 2022-12-20 8:59 ` jskumari at gcc dot gnu.org @ 2022-12-21 6:46 ` guojiufu at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: guojiufu at gcc dot gnu.org @ 2022-12-21 6:46 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108073 --- Comment #2 from Jiu Fu Guo <guojiufu at gcc dot gnu.org> --- (In reply to Surya Kumari Jangala from comment #1) > Hi Jiu Fu Guo, are you working on this bug? If not, I would like to take > this up. Thanks for your asking! I drafted an experimental patch. Welcome for any comments or refactoring :) ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2022-12-21 6:46 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-12-12 12:15 [Bug c/108073] New: [rs6000] sub-optimal float member accessing on struct parameter guojiufu at gcc dot gnu.org 2022-12-12 12:30 ` [Bug middle-end/108073] " pinskia at gcc dot gnu.org 2022-12-20 8:59 ` jskumari at gcc dot gnu.org 2022-12-21 6:46 ` guojiufu at gcc dot gnu.org
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