https://gcc.gnu.org/bugzilla/show_bug.cgi?id=18233
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Depends on| |94956
Resolution|--- |FIXED
Target Milestone|--- |11.2
Status|NEW |RESOLVED
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
So this is fixed in a few different ways but fully with r11-194.
For x86 with cmov (!=i386), this was fixed in GCC 4.5.0 where the ffs is
expanded at expand time to use ctz and cmov.
without cmov, this was only fixed in GCC 11 with r11-194 which changes ffs to
ctz if ctz has a known 0 alrgument which x86 has.
So closing as fixed for GCC 11; There is already a testcase for this too;
gcc.target/i386/pr94956.c .
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94956
[Bug 94956] Unable to remove impossible ffs() test for zero
