On 2022/10/10 18:25, Richard Sandiford wrote:
> "dongbo (E)" <dongbo4@huawei.com> writes:
>> Hi, Richard.
>>
>> On 2022/9/30 22:54, Richard Sandiford wrote:
>>> "dongbo (E)" <dongbo4@huawei.com> writes:
>>>> We tried to put `S_H` in front of `NIL`:
>>>>
>>>> ```
>>>>
>>>>        #define OP_SVE_Vv_HSD                        \
>>>> {                                                               \
>>>>          QLF2(S_H,S_H),                                      \
>>>>          QLF2(S_S,S_S),                                       \
>>>>          QLF2(S_D,S_D),                                      \
>>>>          QLF2(S_H,NIL),                                       \
>>>>          QLF2(S_S,NIL),                                       \
>>>>          QLF2(S_D,NIL),                                       \
>>>>        }
>>>>
>>>> ```
>>> Yeah, good point.  It should be in this order, like you say.
>>>
>>> The fixes you mention look correct to me.
>>>
>>>> But assembler will fail in `match_operands_qualifier` :(.
>>>>
>>>> ```
>>>>
>>>>        match_operands_qualifier (aarch64_inst *inst, bool update_p)
>>>>        {
>>>>            ...
>>>>            if (!aarch64_find_best_match (...))
>>>>            ...
>>>>            if (inst->opcode->flags & F_STRICT)
>>>>            {
>>>>                /* Require an exact qualifier match, even for NIL
>>>> qualifiers.  */
>>>>                nops = aarch64_num_of_operands (inst->opcode);
>>>>                for (i = 0; i < nops; ++i)
>>>>                    if (inst->operands[i].qualifier != qualifiers[i])
>>>>                        return false;
>>>>            }
>>>>        }
>>>>
>>>> ```
>>> I think that's a misfeature of the F_STRICT handling.  Does it work
>>> with the patch below?
>> We also found a way to fix the F_STRICT matching failure. See patch
>> below. :)
>>
>> The main point is to give another `find_best_match` try when we get a
>> qualifier mismatch for HSD operands.
> I think it's simpler than that.  Here's the patch I meant to send
> (which is more -s than +s).

Looks better than ours.

All GAS tests passed with this patch. Thanks.


I think we can make this done via two separate patches:

`0001-aarch64-Tweak-handling-of-F_STRICT.patch` and

`Allow explicit size specifier for predicate operand of {sq, uq, }{incp, 
decp}.patch` (patch below, rewritten already).


Best Regards,

Dong Bo