[PATCH v3 3/7] x86: re-work insn/suffix recognition

[Jan Beulich]

On 06.10.2022 08:15, Jan Beulich via Binutils wrote:
> On 06.10.2022 01:52, H.J. Lu wrote:
>> Does the new assembler work on Linux kernel which has "rep movsd"?
> 
> No. And it shouldn't, as they should never have used MOVSD. The only valid
> mnemonic (in AT&T syntax) is MOVSL. If you're meaning to suggest that we
> continue to support MOVSD in AT&T mode, then this will - once again for
> consistency - need extending to _all_ other D-suffixable insns the SDM
> specifies. I can only repeat what I've said before: Consistency is a
> requirement such that users can predict assembler behavior.

Note how Clang's integrated assembler doesn't even support CMPSD as a
string instruction - that's imo yet more odd behavior, and likely
attributed _solely_ to the goal of wanting to work around code wrongly
using such.

Jan