On 23/01/15 16:39, Jan Beulich wrote:
> Following a compiler change done in 2012, make use of the fact that for
> non-zero input BSF and TZCNT produce the same numeric result (EFLAGS
> setting differs), and that CPUs not knowing of TZCNT will treat the
> instruction as BSF (i.e. ignore what looks l
Following a compiler change done in 2012, make use of the fact that for
non-zero input BSF and TZCNT produce the same numeric result (EFLAGS
setting differs), and that CPUs not knowing of TZCNT will treat the
instruction as BSF (i.e. ignore what looks like a REP prefix to them).
The assumption here
