public inbox for gcc-bugs@sourceware.org help / color / mirror / Atom feed
* [Bug rtl-optimization/56876] New: Combine does not invent new moves @ 2013-04-08 14:24 glisse at gcc dot gnu.org 2013-04-08 15:53 ` [Bug target/56876] " pinskia at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: glisse at gcc dot gnu.org @ 2013-04-08 14:24 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56876 Bug #: 56876 Summary: Combine does not invent new moves Classification: Unclassified Product: gcc Version: 4.9.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: rtl-optimization AssignedTo: unassigned@gcc.gnu.org ReportedBy: glisse@gcc.gnu.org Target: x86_64-linux-gnu Hello, I am looking at this testcase: typedef unsigned long long vec __attribute__((vector_size(16))); vec g; vec f1(vec a, vec b){ return ~a&b; } vec f2(vec a, vec b){ return ~g&b; } which compiles to: f1: pandn %xmm1, %xmm0 f2: pcmpeqd %xmm0, %xmm0 pxor g(%rip), %xmm0 pand %xmm1, %xmm0 whereas I would like to get, like I do with the _mm_andnot_si128 builtin: movdqa g(%rip), %xmm0 pandn %xmm1, %xmm0 It seems that combine cannot match the pandn pattern because the first argument is a memory load and not a register. In this case, it would be better if it emitted a move to put it in a register so it can match, instead of giving up. I don't know if there is a good way to characterize such situations where an extra move is worth it. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/56876] Combine does not invent new moves 2013-04-08 14:24 [Bug rtl-optimization/56876] New: Combine does not invent new moves glisse at gcc dot gnu.org @ 2013-04-08 15:53 ` pinskia at gcc dot gnu.org 2021-12-26 22:38 ` pinskia at gcc dot gnu.org 2021-12-27 5:47 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2013-04-08 15:53 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56876 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Component|rtl-optimization |target --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> 2013-04-08 15:53:40 UTC --- This sounds more like a target issue where prereload instructions are too strict. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/56876] Combine does not invent new moves 2013-04-08 14:24 [Bug rtl-optimization/56876] New: Combine does not invent new moves glisse at gcc dot gnu.org 2013-04-08 15:53 ` [Bug target/56876] " pinskia at gcc dot gnu.org @ 2021-12-26 22:38 ` pinskia at gcc dot gnu.org 2021-12-27 5:47 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-12-26 22:38 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56876 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever confirmed|0 |1 Last reconfirmed| |2021-12-26 Known to fail| |4.7.3 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/56876] Combine does not invent new moves 2013-04-08 14:24 [Bug rtl-optimization/56876] New: Combine does not invent new moves glisse at gcc dot gnu.org 2013-04-08 15:53 ` [Bug target/56876] " pinskia at gcc dot gnu.org 2021-12-26 22:38 ` pinskia at gcc dot gnu.org @ 2021-12-27 5:47 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-12-27 5:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56876 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution|--- |DUPLICATE --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Dup of bug 53652. *** This bug has been marked as a duplicate of bug 53652 *** ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-12-27 5:47 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2013-04-08 14:24 [Bug rtl-optimization/56876] New: Combine does not invent new moves glisse at gcc dot gnu.org 2013-04-08 15:53 ` [Bug target/56876] " pinskia at gcc dot gnu.org 2021-12-26 22:38 ` pinskia at gcc dot gnu.org 2021-12-27 5:47 ` pinskia at gcc dot gnu.org
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).