On Mon, Apr 29, 2019 at 09:24:12AM +0800, Zhao, Yakui wrote: > Yes. "movq" only indicates explicitly that it is 64-bit mov as ACRN guest > only works under 64-bit mode. > I also check the usage of "mov" and "movq" in this scenario. There is no > difference except that the movq is an explicit 64-op.
Damn, I'm tired of explaining this: it is explicit only to the code reader. gcc generates the *same* instruction no matter whether it has a "q" suffix or not as long as the destination register is a 64-bit one. If you prefer to have it explicit, sure, use "movq". -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.