http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53399
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Summary|"*ffs" pattern generates |"*ffs" pattern generates
|wrong code with BMI enabled |wrong code with BMI enabled
|(for corner cases) |
--- Comment #8 from H.J. Lu <hjl.tools at gmail dot com> 2012-05-20 16:18:25
UTC ---
BSF and tzcnt are different with zero input.
BSF sets ZF with zero input and tzcnt set CF
with zero input.