[Bug middle-end/50168] __builtin_ctz() and intrinsics __bsr(), __bsf() generate suboptimal code on x86_64

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50168

Richard Guenther <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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          Component|c                           |middle-end

--- Comment #5 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-24 
08:16:06 UTC ---
I'd say "undefined" is a good enough reason to optimize the case (as opposed
to "target implementation defined" whose behavior we'd need to preserve).