[PATCH 7/8] Support APX NF

[Jan Beulich]

On 02.11.2023 11:15, Cui, Lili wrote:
>> On 19.09.2023 17:25, Cui, Lili wrote:
>>> @@ -7652,6 +7680,13 @@ match_template (char mnem_suffix)
>>>  	  continue;
>>>  	}
>>>
>>> +      /* Check if nf prefix are valid.  */
>>> +      if (check_NfPrefix (t))
>>> +	{
>>> +	  specific_error = progress (i.error);
>>> +	  continue;
>>> +	}
>>
>> Is it helpful (e.g. diagnostic-wise) to have this check so late? If so, is it useful to
>> "continue" when this is the only thing that doesn't match?
>> No other template is going to match in such an event, afaict.
>>
> 
> Yes, it is useful to continue.
> For example" {nf}  add  $123, %bl "
> In order, we first find legacy add, then the judgment finds they don’t match, then continue to find the second template which has NF.
> 
> add, 0x83/0, 0, Modrm|No_bSuf|No_sSuf|HLEPrefixLock, { Imm8S, Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex }
> add, 0x83/0, APX_F, Modrm|No_bSuf|No_sSuf|EVex128|EVexMap4|NF, { Imm8S, Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex }

Hmm, I wonder whether NF-needed-but-no-permitted-by-template shouldn't be a
relatively early check: It's pretty cheap and avoids doing a number of more
involved checks then.

Jan