[PATCH v2] x86: Support ZHAOXIN GMI instructions

[Jan Beulich]

On 15.10.2024 05:02, Jiang, Haochen wrote:
>> From: mayshao-oc <mayshao-oc@zhaoxin.com>
>> Sent: Tuesday, October 15, 2024 9:19 AM
>>
> @@ -13086,6 +13118,21 @@ OP_0f07 (instr_info *ins, int bytemode, int sizeflag)
>    return OP_E (ins, bytemode, sizeflag);
>  }
>  
> +/* montmul instruction need display repz and skip modrm */
> +
> +static bool
> +MONTMUL_Fixup (instr_info *ins, int bytemode, int sizeflag)
> +{
> +  (void) bytemode;
> +  (void) sizeflag;
> 
> What are these two lines for?

ATTRIBUTE_UNUSED wants using instead.

> And you will need MODRM_CHECK;
> and modrm.mod invalid check. You could take OP_Skip_MODRM
> as reference.

I think OP_Skip_MODRM() simply wants invoking from here. That'll
deal with ...

> +  /* The 0xf3 prefix should be displayed as "repz" for montmul. */
> +  if (ins->prefixes & PREFIX_REPZ)
> +    ins->all_prefixes[ins->last_repz_prefix] = 0xf3;
> +  ins->codep++;
> +  ins->has_skipped_modrm = true;
> +  return true;
> +}

... part of the omissions: Right now both modrm.mod and modrm.rm
aren't being checked here.

> Also, in gas/NEWS, could you put the entry at the very beginning?

I don't think the placement there matters much, as long as it's in the
correct section.

Jan