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[Bug target/50131] Optimize x = -1 with "or" for -O
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sun, 21 Aug 2011 09:19:28 +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
--- Comment #4 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-21 09:19:28 UTC ---
I'm sure or $-1,reg doesn't avoid the data dependence on reg and may even
result in hitting partial reg stall issues. Surely xor reg,reg; not reg
might be another alternative?