oysteikt/mpd
0
0
Fork 0
Code Issues Pull Requests Releases Activity

pcm/Volume: remove optimized i386 assembly

Browse Source 
This code is unable to dither.  Until we implement that, let's remove
the code for now.  i386 isn't relevant anymore anyway.
This commit is contained in:
Max Kellermann 2013-12-28 17:23:48 +01:00
parent 2a3a18a283
commit f3bbe4bb1f
1 changed files with 0 additions and 50 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
src/pcm/Volume.cxx
View File

@ -42,56 +42,6 @@ pcm_volume_sample(typename Traits::value_type _sample,
return PcmClamp<F, Traits>(sample); return PcmClamp<F, Traits>(sample);
} }
#ifdef __i386__
/**
* Optimized volume function for i386. Use the EDX:EAX 2*32 bit
* multiplication result instead of emulating 64 bit multiplication.
*/
static inline int32_t
pcm_volume_sample_24(int32_t sample, int32_t volume, gcc_unused int32_t dither)
{
int32_t result;
asm(/* edx:eax = sample * volume */
"imul %2\n"
/* "add %3, %1\n" dithering disabled for now, because we
have no overflow check - is dithering really important
here? */
/* eax = edx:eax / PCM_VOLUME_1 */
"sal $22, %%edx\n"
"shr $10, %1\n"
"or %%edx, %1\n"
: "=a"(result)
: "0"(sample), "r"(volume) /* , "r"(dither) */
: "edx"
);
return result;
}
template<>
inline int32_t
pcm_volume_sample<SampleFormat::S24_P32,
SampleTraits<SampleFormat::S24_P32>>(int32_t sample,
int volume)
{
return pcm_volume_sample_24(sample, volume, pcm_volume_dither());
}
template<>
inline int32_t
pcm_volume_sample<SampleFormat::S32,
SampleTraits<SampleFormat::S32>>(int32_t sample, int volume)
{
return pcm_volume_sample_24(sample, volume, pcm_volume_dither());
}
#endif
template<SampleFormat F, class Traits=SampleTraits<F>> template<SampleFormat F, class Traits=SampleTraits<F>>
static void static void
pcm_volume_change(typename Traits::pointer_type dest, pcm_volume_change(typename Traits::pointer_type dest,