[PATCH] D23166: [X86] Improve code size on X86 segment moves

[Joerg Sonnenberger via llvm-commits]

On Thu, Aug 04, 2016 at 01:45:39PM -0400, Nirav Davé via llvm-commits wrote:
> The ISA doesn't actually have a 32-bit mov instruction of this form (though
> all the processors I've seen accept the bytes pattern associated with the
> 32-bit variant). I doubt that anyone dealing with explicit segment
> twiddling ever wants the effectless prefix added. AFAIK these instructions
> are only ever emitted via explicit assembly so they it would be easy enough
> to add the byte via an explicit ".byte" directive.

Sometimes people want explicitly sized assembler for later runtime
patching. I'm not sure it matters in this case.

Joerg