[FFmpeg-devel] [PATCH] do not pointlessly use REG_BP

[Reimar Döffinger]

On Fri, Jan 01, 2010 at 03:38:57AM +0100, Michael Niedermayer wrote:
> On Fri, Jan 01, 2010 at 02:34:42AM +0100, Reimar D?ffinger wrote:
> > On Fri, Jan 01, 2010 at 01:32:50AM +0100, Michael Niedermayer wrote:
> > > On Thu, Dec 31, 2009 at 10:34:35PM +0100, Reimar D?ffinger wrote:
> > > > Hello,
> > > > this might cause compilation issues, since EBP might not be available
> > > > even on x86_64.
> > > > Since there are enough register, this patch just lets gcc choose a
> > > > register:
> > > > Index: swscale_template.c
> > > > ===================================================================
> > > > --- swscale_template.c  (revision 30151)
> > > > +++ swscale_template.c  (working copy)
> > > > @@ -1225,18 +1225,19 @@
> > > >          case PIX_FMT_RGB32:
> > > >              if (CONFIG_SWSCALE_ALPHA && c->alpPixBuf) {
> > > >  #if ARCH_X86_64
> > > > +                x86_reg tmp;
> > > >                  __asm__ volatile(
> > > > -                    YSCALEYUV2RGB(%%REGBP, %5)
> > > > -                    YSCALEYUV2RGB_YA(%%REGBP, %5, %6, %7)
> > > > +                    YSCALEYUV2RGB(%0, %6)
> > > > +                    YSCALEYUV2RGB_YA(%0, %6, %7, %8)
> > > >                      "psraw                  $3, %%mm1       \n\t" /* abuf0[eax] - abuf1[eax] >>7*/
> > > >                      "psraw                  $3, %%mm7       \n\t" /* abuf0[eax] - abuf1[eax] >>7*/
> > > >                      "packuswb            %%mm7, %%mm1       \n\t"
> > > > -                    WRITEBGR32(%4, 8280(%5), %%REGBP, %%mm2, %%mm4, %%mm5, %%mm1, %%mm0, %%mm7, %%mm3, %%mm6)
> > > > +                    WRITEBGR32(%5, 8280(%6), %%REGBP, %%mm2, %%mm4, %%mm5, %%mm1, %%mm0, %%mm7, %%mm3, %%mm6)
> > >                                                 ^^^^^^^
> > > and please test it next time
> > 
> > Unfortunately letting the compiler choose the register is not easily
> > possible due to hardcoded numeric arguments used in the macros.
> > Alternative version tested with
> 
> ok if output is binary identical & you made sure the code is actually
> used

done and applied.