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* [Bug tree-optimization/100858] New: Simple common code hoisting is not performed @ 2021-06-01 15:16 nok.raven at gmail dot com 2021-06-02 8:01 ` [Bug tree-optimization/100858] " rguenth at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: nok.raven at gmail dot com @ 2021-06-01 15:16 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100858 Bug ID: 100858 Summary: Simple common code hoisting is not performed Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: nok.raven at gmail dot com Target Milestone: --- void bar(); int foo(bool f) { if (f) { bar(); return 1; } else { bar(); return 2; } } ; GCC foo(bool): sub rsp, 8 test dil, dil je .L2 call bar() mov eax, 1 add rsp, 8 ret .L2: call bar() mov eax, 2 add rsp, 8 ret ; Clang foo(bool): push rbx mov ebx, edi call bar() mov eax, 2 sub eax, ebx pop rbx ret https://godbolt.org/z/j9eKG1dds ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/100858] Simple common code hoisting is not performed 2021-06-01 15:16 [Bug tree-optimization/100858] New: Simple common code hoisting is not performed nok.raven at gmail dot com @ 2021-06-02 8:01 ` rguenth at gcc dot gnu.org 2021-06-02 23:18 ` nok.raven at gmail dot com 2021-07-28 20:17 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu.org @ 2021-06-02 8:01 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100858 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2021-06-02 Ever confirmed|0 |1 --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- That's really a duplicate of 100858 - this case can be handled by sinking as well since we "sink" the return. Make it void bar(); int foo(bool f) { if (f) { bar(); __builtin_abort (); } else { bar(); return 2; } } to force hoisting. Hoisting is done by PRE but that requires a LHS and doesn't handle calls with side-effects. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/100858] Simple common code hoisting is not performed 2021-06-01 15:16 [Bug tree-optimization/100858] New: Simple common code hoisting is not performed nok.raven at gmail dot com 2021-06-02 8:01 ` [Bug tree-optimization/100858] " rguenth at gcc dot gnu.org @ 2021-06-02 23:18 ` nok.raven at gmail dot com 2021-07-28 20:17 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: nok.raven at gmail dot com @ 2021-06-02 23:18 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100858 --- Comment #2 from Nikita Kniazev <nok.raven at gmail dot com> --- (In reply to Richard Biener from comment #1) > That's really a duplicate of 100858 - this case can be handled by sinking as > well > since we "sink" the return. Make it > > void bar(); > > int foo(bool f) > { > if (f) { > bar(); > __builtin_abort (); > } > else { > bar(); > return 2; > } > } > to force hoisting. I have a hard time in finding this as equivalent to the original code. > Hoisting is done by PRE but that requires a LHS and doesn't handle calls with side-effects. That seems like an artificial limitation. Why we cannot hoist the bar call? ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/100858] Simple common code hoisting is not performed 2021-06-01 15:16 [Bug tree-optimization/100858] New: Simple common code hoisting is not performed nok.raven at gmail dot com 2021-06-02 8:01 ` [Bug tree-optimization/100858] " rguenth at gcc dot gnu.org 2021-06-02 23:18 ` nok.raven at gmail dot com @ 2021-07-28 20:17 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-07-28 20:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100858 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Severity|normal |enhancement CC| |pinskia at gcc dot gnu.org ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-07-28 20:17 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-01 15:16 [Bug tree-optimization/100858] New: Simple common code hoisting is not performed nok.raven at gmail dot com 2021-06-02 8:01 ` [Bug tree-optimization/100858] " rguenth at gcc dot gnu.org 2021-06-02 23:18 ` nok.raven at gmail dot com 2021-07-28 20:17 ` pinskia at gcc dot gnu.org
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