[Ffmpeg-devel] libswscale coding style

[Diego Biurrun]

On Fri, Apr 27, 2007 at 07:14:30PM +0200, Diego Biurrun wrote:
> On Fri, Apr 27, 2007 at 12:29:28PM +0200, Ivo wrote:
> > 
> > On Friday 27 April 2007 03:23, Marc Hoffman wrote:
> > > Diego Biurrun writes:
> > >  > I've just implemented pre-commit hooks for libswscale that check for
> > >  > tabs and trailing whitespace, same as for FFmpeg.
> > >  >
> > >  > I'm in the process of removing trailing whitespace and tabs and
> > >  > reformatting the files while I'm at it.
> > >  > What's the preferred style for inline ASM, things like
> > >  > rgb2rgb_template.c:100?
> > 
> > I would really like to see the "instr op, op\n\t" be replaced by something 
> > more readable, like:
> > 
> >     "   movq %%mm0, %%mm1       \n"
> >     "   movq %%mm1, %%mm2       \n"
> >     "   punpckldq 9%1, %%mm1    \n"
> > 
> > et cetera. Perhaps even align the operands, although that'll be a lot of 
> > work.
> 
> I think I'll align them while I'm at it.  What's the preferred style?

Let me be more specific:

variant 1)

  __asm __volatile(
      PREFETCH"        32%1           \n\t"
      "movd              %1, %%mm0    \n\t"
      "punpckldq        3%1, %%mm0    \n\t"
      "movd             6%1, %%mm1    \n\t"
      "punpckldq        9%1, %%mm1    \n\t"
      "movd            12%1, %%mm2    \n\t"
      "punpckldq       15%1, %%mm2    \n\t"
      "movd            18%1, %%mm3    \n\t"
      "punpckldq       21%1, %%mm3    \n\t"
      "pand           %%mm7, %%mm0    \n\t"
      "pand           %%mm7, %%mm1    \n\t"
      "pand           %%mm7, %%mm2    \n\t"
      "pand           %%mm7, %%mm3    \n\t"
      MOVNTQ"         %%mm0,   %0     \n\t"
      MOVNTQ"         %%mm1,  8%0     \n\t"
      MOVNTQ"         %%mm2, 16%0     \n\t"
      MOVNTQ"         %%mm3, 24%0"
      :"=m"(*dest)
      :"m"(*s)
      :"memory");


or variant 2)

  __asm __volatile(
      PREFETCH"       32%1            \n\t"
      "movd           %1,    %%mm0    \n\t"
      "punpckldq      3%1,   %%mm0    \n\t"
      "movd           6%1,   %%mm1    \n\t"
      "punpckldq      9%1,   %%mm1    \n\t"
      "movd           12%1,  %%mm2    \n\t"
      "punpckldq      15%1,  %%mm2    \n\t"
      "movd           18%1,  %%mm3    \n\t"
      "punpckldq      21%1,  %%mm3    \n\t"
      "pand           %%mm7, %%mm0    \n\t"
      "pand           %%mm7, %%mm1    \n\t"
      "pand           %%mm7, %%mm2    \n\t"
      "pand           %%mm7, %%mm3    \n\t"
      MOVNTQ"         %%mm0, %0       \n\t"
      MOVNTQ"         %%mm1, 8%0      \n\t"
      MOVNTQ"         %%mm2, 16%0     \n\t"
      MOVNTQ"         %%mm3, 24%0"
      :"=m"(*dest)
      :"m"(*s)
      :"memory");

?

Diego