"Francois G. Dorais" <dorais@gauss.dartmouth.edu> writes:
>
> It could be binutils, but more often it's gcc which produces silly
> instructions.
Could be either, I suppose the .s output from gcc will show. Debian
packaged gas 2.13.90.0.16 seems to accept for instance
bsfq %rax, %rcx
That bit of longlong.h was probably created before gcc/binutils stuff
was finalized though.