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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/112819] New: rearrange branches to improve code generation Date: Sat, 02 Dec 2023 01:10:23 +0000 [thread overview] Message-ID: <bug-112819-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112819 Bug ID: 112819 Summary: rearrange branches to improve code generation Product: gcc Version: 14.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: enhancement Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: pinskia at gcc dot gnu.org Target Milestone: --- Take: ``` bool src(char *a, int l) { if(l < 1) { return false; } if(*a != 'a') { return false; } if(l < 2) { return false; } return true; } bool tgt(char *a, int l) { if(l < 1) { return false; } if(l < 2) { return false; } if(*a != 'a') { return false; } return true; } ``` You would expect these 2 to produce both the same code but only tgt produces decent code. That is because we can merge `l < 1` with `l < 2` into just `l < 2` (or `l <= 1`). This might be an reassociation problem or something else.
next reply other threads:[~2023-12-02 1:10 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-12-02 1:10 pinskia at gcc dot gnu.org [this message] 2023-12-04 6:57 ` [Bug tree-optimization/112819] " rguenth at gcc dot gnu.org
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