[FFmpeg-devel] [PATCH] intreadwrite: Altivec implementations of AV_COPY128 and AV_ZERO128.

[Reimar Döffinger]

On Sun, Mar 08, 2015 at 01:21:20PM -0300, James Almer wrote:
> On 08/03/15 1:16 PM, Reimar Döffinger wrote:
> > Slightly (ca. 4%?) faster and smaller ff_h264_decode_mb_cavlc
> > in my tests on a G4 7450.
> > 
> > Signed-off-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
> > ---
> >  libavutil/ppc/intreadwrite.h | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/libavutil/ppc/intreadwrite.h b/libavutil/ppc/intreadwrite.h
> > index 7671676..65b346e 100644
> > --- a/libavutil/ppc/intreadwrite.h
> > +++ b/libavutil/ppc/intreadwrite.h
> > @@ -24,6 +24,16 @@
> >  #include <stdint.h>
> >  #include "config.h"
> >  
> > +#if HAVE_ALTIVEC
> > +#include "util_altivec.h"
> > +#if HAVE_BIGENDIAN
> > +#define AV_COPY128(d, s) vec_st(vec_ld(0, (const unsigned char *)(s)), 0, (unsigned char *)(d))
> > +#else
> > +#define AV_COPY128(d, s) vec_vsx_st(vec_vsx_ld(0, (const unsigned char *)(s)), 0, (unsigned char *)(d))
> > +#endif
> > +#define AV_ZERO128(d) VEC_ST(vec_splat_u8(0), 0, (unsigned char *)(d))
> > +#endif
> 
> Why not use static av_always_inline functions, like it's done on other arches (and 
> also for other defines in ppc)?

Well, it would mean a define and the function itself for overall around 4
lines of code what like this is a single line.
I don't have much of an opinion, I did that at first, but it just seemed
fairly bloated for what it does.
Also, not using a function is consistent with what the implementations
in the non-arch-specific intreadwrite.h do.