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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/95926] New: Failure to optimize xor pattern when Date: Sat, 27 Jun 2020 02:08:10 +0000 [thread overview] Message-ID: <bug-95926-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95926 Bug ID: 95926 Summary: Failure to optimize xor pattern when Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: gabravier at gmail dot com Target Milestone: --- bool f(bool a, bool b) { bool tmp = a & b; return (tmp ^ b) | (tmp ^ a); } This code does not optimize as well as this code : bool f(bool a, bool b) { return ((a & b) ^ b) | ((a & b) ^ a); } which optimizes to `return a ^ b;`. This seems rather odd considering that they are equivalent and the first example is just a simplification of the second (i.e. made more readable).
next reply other threads:[~2020-06-27 2:08 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-27 2:08 gabravier at gmail dot com [this message] 2020-06-27 11:59 ` [Bug tree-optimization/95926] Failure to optimize xor pattern when using temporary variable glisse at gcc dot gnu.org 2020-06-29 9:45 ` rguenth at gcc dot gnu.org 2021-08-15 0:07 ` pinskia at gcc dot gnu.org
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