[FFmpeg-devel] [RFC] clobbers for XMM registers

[Måns Rullgård]

Ramiro Polla <ramiro.polla at gmail.com> writes:

> 2010/9/30 M?ns Rullg?rd <mans at mansr.com>:
>> Ramiro Polla <ramiro.polla at gmail.com> writes:
>>> What about
>>> #if HAVE_XMM_CLOBBERS
>>> # ? ?define XMM_CLOBBERS(a, ...) __VA_ARGS__
>>> #else
>>> # ? ?define XMM_CLOBBERS(a, ...) a
>>> #endif
>>>
>>> to be used as in lavc/x86/fft_sse.c:
>>> ? ? ? ? :"+r"(j), "+r"(k)
>>> ? ? ? ? :"r"(output+n4), "r"(output+n4*3),
>>> ? ? ? ? ?"m"(*m1m1m1m1)
>>> ? ? ? ? XMM_CLOBBERS(, : "%xmm0", "%xmm1", "%xmm7")
>>> ? ? );
>>
>> That falls over if any other clobbers are needed.
>
> If any other clobbers are needed they could be written before the macro.

That won't work.

-- 
M?ns Rullg?rd
mans at mansr.com