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* [Bug rtl-optimization/114693] New: `expand` introduce redundant store facing logic expression @ 2024-04-11 11:38 absoler at smail dot nju.edu.cn 2024-04-11 11:43 ` [Bug target/114693] " pinskia at gcc dot gnu.org 2024-04-11 11:59 ` pinskia at gcc dot gnu.org 0 siblings, 2 replies; 3+ messages in thread From: absoler at smail dot nju.edu.cn @ 2024-04-11 11:38 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114693 Bug ID: 114693 Summary: `expand` introduce redundant store facing logic expression Product: gcc Version: 13.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: absoler at smail dot nju.edu.cn Target Milestone: --- A simple case, regression from gcc-5 ``` struct S{ char f0; int f3; } s; int g, f; void func_1() { int a = 0; s.f0 = 1 && ((3 > a) & g); } ``` compiled with -O2 : ``` func_1(): 401340: mov 0x10846(%rip),%eax # 411b8c <g> 401346: mov %al,0x10844(%rip) # 411b90 <s> 40134c: andb $0x1,0x1083d(%rip) # 411b90 <s> 401353: retq ``` it seems "1 && " interfere the compiler, after removing it the compiler generates: ``` func_1(): 401340: movzbl 0x10845(%rip),%eax # 411b8c <g> 401347: and $0x1,%eax 40134a: mov %al,0x10840(%rip) # 411b90 <s> 401350: retq ``` ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/114693] `expand` introduce redundant store facing logic expression 2024-04-11 11:38 [Bug rtl-optimization/114693] New: `expand` introduce redundant store facing logic expression absoler at smail dot nju.edu.cn @ 2024-04-11 11:43 ` pinskia at gcc dot gnu.org 2024-04-11 11:59 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-04-11 11:43 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114693 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target| |x86_64 Component|rtl-optimization |target --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- This is a target specific issue on how x86_64 backend patterns are done IIRC. ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug target/114693] `expand` introduce redundant store facing logic expression 2024-04-11 11:38 [Bug rtl-optimization/114693] New: `expand` introduce redundant store facing logic expression absoler at smail dot nju.edu.cn 2024-04-11 11:43 ` [Bug target/114693] " pinskia at gcc dot gnu.org @ 2024-04-11 11:59 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2024-04-11 11:59 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114693 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |14.0 Resolution|--- |FIXED Keywords| |missed-optimization Status|UNCONFIRMED |RESOLVED --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Actually this is fixed on the trunk. This is what we got in GCC 13 and before: g.0_1 = g; _2 = (_Bool) g.0_1; _3 = (char) _2; s.f0 = _3; But in GCC 14+ we get: g.0_1 = g; _2 = g.0_1 & 1; _3 = (char) _2; s.f0 = _3; This was fixed by r14-6420-g85c5efcffed19c . ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2024-04-11 11:59 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2024-04-11 11:38 [Bug rtl-optimization/114693] New: `expand` introduce redundant store facing logic expression absoler at smail dot nju.edu.cn 2024-04-11 11:43 ` [Bug target/114693] " pinskia at gcc dot gnu.org 2024-04-11 11:59 ` pinskia at gcc dot gnu.org
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