Hi,

On Tue, May 15, 2012 at 6:20 AM, Christophe Gisquet
<[email protected]> wrote:
> 2012/5/11 Ronald S. Bultje <[email protected]>:
>> I agree a cpuflags-based SPLATW implementation would be wonderful. Do
>> you have time to go through all current users of SPLATW to ensure we
>> don't break anything (i.e. make it use mmx code where mmx2 was
>> intended because it doesn't use cpuflags yet)? If not, I can do that
>> over the weekend, hopefully.
>
> The issue is that the full intent of SPLATW can't be handled by MMX.
> The most common use, and the easiest to deal with, is the case where
> 3rd argument is 0. I see 2 ways (surely there are more to deal with
> that:
> 1) Is it possible, and is it desirable to have SPLATW macro cleanly
> cause an error when called from code invoking it in a MMX context?
> Then most of the code could stay in, at the cost of maybe a semantic
> weirdness for MMX

mmx version:

movaifnidn %1, %2
%if %3 & 2
punpckhwd %1, %1
%else
punpcklwd %1, %1
%endif
%if %3 & 1
punpckhdq %1, %1
%else
punpckldq %1, %1
%endif

I agree this is ugly, but it's the best I can think of.

Ronald
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