[FFmpeg-devel] [PATCH 6/8] sbcenc: add MMX optimizations

[Ronald S. Bultje]

Hi,

On Wed, Dec 20, 2017 at 4:58 PM, James Almer <jamrial at gmail.com> wrote:

> On 12/17/2017 6:47 PM, Aurelien Jacobs wrote:
> > +;*******************************************************************
> > +;void ff_sbc_calc_scalefactors(int32_t sb_sample_f[16][2][8],
> > +;                              uint32_t scale_factor[2][8],
> > +;                              int blocks, int channels, int subbands)
> > +;*******************************************************************
> > +INIT_MMX mmx
> > +cglobal sbc_calc_scalefactors, 5, 7, 3, sb_sample_f, scale_factor,
> blocks, channels, subbands, ptr, blk
>
> On x86_64 (Windows at least), the high 32 bits of registers storing int
> arguments may contain garbage, so you need to work around it.


I think that's only for stack arguments, i.e. only subbands (not blocks or
channels).

Ronald