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From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/106950] New: Missed PRE full redundancy without post-loop use Date: Thu, 15 Sep 2022 12:45:11 +0000 [thread overview] Message-ID: <bug-106950-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106950 Bug ID: 106950 Summary: Missed PRE full redundancy without post-loop use Product: gcc Version: 13.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org Target Milestone: --- when we have the situation of PR106922, aka g++.dg/tree-ssa/pr106922.C which is XFAILed on !lp64 because of this there's mem = 0; do { if (mem) mem = 0; if (mem) // as 'char' instead of 'bool', maybe relevant bar (); if (i++ != n) break; } while (1); .. = mem; with the use of 'mem' after the loop we get that antic-in in the loop exit condition block and eventually figure the full redundancy in the conditional redundant set to zero during PRE insertion. When that 'mem' after the loop is _not_ there this isn't triggered (possibly because of the 'char' vs. 'bool' here, but then one can eventually elide the whole if (mem) bar () code).
next reply other threads:[~2022-09-15 12:45 UTC|newest] Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-15 12:45 rguenth at gcc dot gnu.org [this message] 2022-09-22 11:12 ` [Bug tree-optimization/106950] " rguenth at gcc dot gnu.org
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