Re: Re: dmix plugin

[Abramo Bagnara <abramo.bagnara@libero.it>]

Jaroslav Kysela wrote:
> 
> On Wed, 19 Feb 2003, Abramo Bagnara wrote:
> 
> > The results are amazing and I'd say Jaroslav has done some mistakes in
> > his handmade asm.
> 
> I don't think so. It seems that my brain still remembers assembler ;-)

I've no doubts about that ;-)

> You passed wrong values to my code so it did unaligned accesses.

I guessed that but I was too lazy to deeply analyze your asm.

> Fixes to make things same:

>                 volatile s32 *sum,
> -               unsigned int dst_step, unsigned int src_step)
> +               unsigned int dst_step,
> +               unsigned int src_step,
> +               unsigned int sum_step)

sum_step is useless I've deliberately removed it.
Please do it also on your code.

> +               ((char *)dst) += dst_step;
> +               ((char *)src) += src_step;

IMHO it's a sane assumption suppose that step is multiple of sample
size.
However this should not have any impact on efficiency (at least I
believe).

> -                       if (unlikely(sample & 0xffff0000))
> +                       if (unlikely(sample & 0x7fff0000))

As Jaroslaw has written this is a mistake and I've verified the right
version has no speed benefits.

-- 
Abramo Bagnara                       mailto:abramo.bagnara@libero.it

Opera Unica                          Phone: +39.546.656023
Via Emilia Interna, 140
48014 Castel Bolognese (RA) - Italy


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