https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95529
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Resolution|--- |WONTFIX
Status|UNCONFIRMED |RESOLVED
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
Please note that "REP BSF" on BMI capable targets decodes as TZCNT, which is
not equal to BSF as far as flags are concerned. BSF sets zero flag on zero
input, where TZCNT sets carry flag on zero input.
GCC emits TZCNT by default on the premise that the same binary can benefit from
TZCNT runing faster than BSF on BMI capable targets. Unfortunatelly, flags
can't be reused due to the difference, explained above.
