Re: [qemu-s390x] [Qemu-devel] [PATCH v1 1/5] s390x/tcg: Implement VECTOR FIND ANY ELEMENT EQUAL

[Richard Henderson]

On 5/22/19 2:16 PM, David Hildenbrand wrote:
> On 22.05.19 17:59, Richard Henderson wrote:
>> On Wed, 22 May 2019 at 07:16, David Hildenbrand <address@hidden> wrote:
>>>> Also plausible.  I guess it would be good to know, anyway.
>>>
>>> I'll dump the parameters when booting Linux. My gut feeling is that the
>>> cc option is basically never used ...
>>
>> It looks like our intuition is wrong about that.
> 
> Thanks for checking!
> 
>>
>> address@hidden:~/glibc/src/sysdeps/s390$ grep -r vfaezbs * | wc -l
>> 15
>>
>> These set cc, use zs, and do not use rt.
>>
>> address@hidden:~/glibc/src/sysdeps/s390$ grep -r 'vfaeb' * | wc -l
>> 3
>>
>> These do not set cc, do not use zs, and do use rt.
>>
>> Those are the only two VFAE forms used by glibc (note that the same
>> variants as 'f' are used by the wide-character strings).
>>
> 
> I guess "rt" and "cc" make the biggest difference. Maybe special case
> these two, result in 4 variants for each of the 3 element sizes?

Sounds good.


r~