On 03/01/16 13:08, Evandro Menezes wrote:
> On 03/01/16 13:02, Wilco Dijkstra wrote:
>> Evandro Menezes wrote:
>>> The meaning of these attributes are not clear to me.  Is there a
>>> reference somewhere about which insns are FP or SIMD or neither?
>> The meaning should be clear, "fp" is a floating point instruction, 
>> "simd" a SIMD one
>> as defined in ARM-ARM.
>>
>>> Indeed, I had to add the Y for the f_mcr insn to match it with nosimd.
>>> However, I didn't feel that it should be moved to the right, since it's
>>> already disparaged.  Am I missing something detail?
>> It might not matter for this specific case, but I have seen reload 
>> forcing the very
>> first alternative without looking at any costs or preferences - as 
>> long as it is legal.
>> This suggests we need to order alternatives from most preferred 
>> alternative to least
>> preferred one.
>>
>> I think it is good enough for commit, James?
>
> Methinks that my issue with those attributes is that I'm not as fluent 
> in AArch64 as I'd like to be.
>
> Please, feel free to edit the patch changing the order then.

    Replace insn to zero up SIMD registers

    gcc/
             * config/aarch64/aarch64.md
             (*movhf_aarch64): Add "movi %0, #0" to zero up register.
             (*movsf_aarch64): Likewise and add "simd" and "fp" attributes.
             (*movdf_aarch64): Likewise.

Swapped the order of the constraints to favor MOVI.

Just say the word...

Thank you,

-- 
Evandro Menezes