From: Sedat Dilek ... > Did someone look at the next/follow-ups in this thread? > For example: D6629 "x86: Emit LAHF/SAHF instead of PUSHF/POPF" [2]?
LAHF and SAHF come with the following note:
This instruction executes as described above in compatibility mode and legacy
mode.
It is valid in 64-bit mode only if CPUID.80000001H:ECX.LAHF-SAHF[bit 0] = 1.
So I suspect they can't be used.
David
