[FFmpeg-devel] [RFC][PATCH] DSPUtilize some functions from APE decoder

Michael Niedermayer michaelni
Thu Jul 3 03:23:56 CEST 2008

On Thu, Jul 03, 2008 at 03:29:07AM +0300, Ivan Kalvachev wrote:
> On 7/3/08, Loren Merritt <lorenm at u.washington.edu> wrote:
> >> +    asm volatile("movd %%xmm7, (%0)\n\t" : "+r"(resp));
> >> +    return res;
> >> +}
> >
> > horizontal sum should be outside the loop
> > pshuflw is faster than pshufd
> Few more things.
> I'm not sure why you use pointer to local variable,
> there must be way to give the return variable directly
> to the asm block, so if compiler pleases and that variable
> is assigned to eax register then "movd" would put the value
> in eax directly and return it this way.

movd %%xmm7, %0\n\t" : "=rm"(res)
might work though ive not tried and x86-64 might have problems
with it

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Breaking DRM is a little like attempting to break through a door even
though the window is wide open and the only thing in the house is a bunch
of things you dont want and which you would get tomorrow for free anyway
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