Opteron: Error: suffix or operands invalid for `bsf'

[Kevin Ryde]

"Francois G. Dorais" <dorais@gauss.dartmouth.edu> writes:
>
> This should work since the problem appears to be that the compiler uses a
> 32-bit register for count, the above should avoid that.

Thanks.  Yep, the destination count is sometimes just an int, and the
constraint doesn't force it into a 64-bit reg.  (Not sure why "r"
doesn't mean a 64-bit reg anyway, but let's not worry about that.)