[Ffmpeg-devel] [PATCH] Faster rgb32tobgr32

[Trent Piepho]

On Tue, 17 Apr 2007, Ivo wrote:

> Hi,
>
> The following patch makes rgb32tobgr32 slightly faster by avoiding an extra
> add and a cmp.
>
> Old C Code, Avg of ten runs: 68345307
> New C Code, Avg of ten runs: 67644935
>
> Old MMX2 Code, Avg of ten runs: 66875441
> New MMX2 Code, Avg of ten runs: 65855368

Don't suppose you know the variance of the ten runs?

+               : "+r"(idx)
+               : "r" (s), "r" (d), "m" (mask32b), "m" (mask32r), "m" (mmx_one)
                : "memory");

It should be "+&r"(idx).  Realistically, idx won't be able to overlap any
of those parameters, but someone could always add a new input that could
overlap.