http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50168
Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2011-08-24 Ever Confirmed|0 |1 --- Comment #7 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-08-24 09:40:44 UTC --- Hm, so the best thing we can do is a peephole recognizing that 10: 48 0f bc ff bsf %rdi,%rdi 14: 48 63 ff movslq %edi,%rdi when rdi is zero it will stay so and the movslq is redundant?