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[Bug target/50131] Optimize x = -1 with "or" for -O
- From: "jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 20 Aug 2011 08:32:12 +0000
- Subject: [Bug target/50131] Optimize x = -1 with "or" for -O
- Auto-submitted: auto-generated
- References: <bug-50131-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50131
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |jakub at gcc dot gnu.org
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-08-20 08:32:12 UTC ---
Is or $-1, reg on all CPUs equally expensive to mov $-1, reg though (as or
generally needs the previous reg content while mov does not; I know some CPUs
special case xor reg, reg, but I doubt or $-1, reg is special cased)?