[PATCH RESEND v2] Aarch64: Allow explicit size specifier for predicate operand of {sq, uq, }{incp, decp}

[Jan Beulich]

On 10.03.2022 12:33, Shaokun Zhang wrote:
> On 2022/3/10 18:38, Jan Beulich wrote:
>> On 10.03.2022 10:38, Shaokun Zhang wrote:
>>> Hi Jan,
>>
>> Despite this, ...
>>
>>> On 2022/3/2 15:36, Shaokun Zhang wrote:
>>>> On 2022/2/21 21:13, Jan Beulich wrote:
>>>>> On 16.02.2022 01:53, Shaokun Zhang wrote:
>>>>>> --- a/gas/testsuite/gas/aarch64/sve-movprfx_23.d
>>>>>> +++ b/gas/testsuite/gas/aarch64/sve-movprfx_23.d
>>>>>> @@ -9,29 +9,29 @@ Disassembly of section .*:
>>>>>>  
>>>>>>  0+ <.*>:
>>>>>>  [^:]+:	04512461 	movprfx	z1.h, p1/m, z3.h
>>>>>> -[^:]+:	256c8021 	incp	z1.h, p1  // note: merging predicate expected due to preceding `movprfx' at operand 2
>>>>>> +[^:]+:	256c8021 	incp	z1.h, p1.h  // note: merging predicate expected due to preceding `movprfx' at operand 2
>>>>>
>>>>> I have a more general question here: Couldn't the spec make optional the
>>>>> use of all the same size specifiers when there are multiple, same element
>>>>> size operands? One such suffix of course needs to be there to disambiguate
>>>>
>>>> We are not from ARM SPEC group and don't know the exact considerations for
>>>> the forbidden omitting suffix. We guess people will have different answers from
>>>> different points of view.
>>>>
>>>> >From our point of view,  a suffix makes the assembly more consistent with the
>>>> scalar versions of `incp`, e.g. `incp x1, p2.b`. And the predicate register acts more
>>>> like a vector register within this instruction, with suffix, the addend for each element
>>>> is clear once reading the assembly string.
>>>>
>>>> Not sure that anyone from ARM in the mail-list can give more hints or thoughts.
>>>>
>>>
>>> No any more comments from Arm guys.
>>>
>>> Is it ok for trunk?
>>
>> ... I assume you understand that I'm not in the position to give you the
>> wanted "okay"?
> 
> Apologies that I don't follow it completely, do you mean that does it need
> someone to agree and take it? Or we need more comments?

Well, as for any patch a maintainer of the code needs to give you their okay.

Jan