[Ffmpeg-devel] [PATCH] Optimization of 'dct_unquantize_h263_intra' for ARM (armv5te) (try2)

[Michael Niedermayer]

Hi

On Sat, Jan 06, 2007 at 06:07:53PM +0200, Siarhei Siamashka wrote:
> Hello,
> 
> An updated patch of dct_unquantize_h263_intra optimization for armv5te is
> attached. It was further optimized based on the comments from Michael
> Niedermayer and now requires 6 cycles to process one element (instead of
> 7 cycles in the previous version). Also I tried to correct the problems
> detected in the previous patch.
> 
> Now I think it is a final version and it would be extremely hard (if possible)
> to optimize it more. It passed all my tests (both synthetic and on real video
> files) and seems to work correctly. If you notice any problems, I'll try to
> fix them in the next revision.
> 
> It processes 8 elements per loop iteration and finally optionally processes 2
> elements in the end. As the number of elements to process tends to be a
> multiple of 8 plus one or two extra elements, overhead should be minimal.
> Typical distribution of nCoeffs for mpeg4 video:
> 

[...]
> Index: libavcodec/armv4l/mpegvideo_arm.c
> ===================================================================
> --- libavcodec/armv4l/mpegvideo_arm.c	(revision 7409)
> +++ libavcodec/armv4l/mpegvideo_arm.c	(working copy)
> @@ -24,10 +24,13 @@
>  #include "../avcodec.h"
>  
>  extern void MPV_common_init_iwmmxt(MpegEncContext *s);
> +extern void MPV_common_init_armv5te(MpegEncContext *s);
>  
>  void MPV_common_init_armv4l(MpegEncContext *s)
>  {
> -#ifdef HAVE_IWMMXT
> +#if defined(HAVE_IWMMXT)

cosmetical change 


[...]
> +/* GCC 3.1 or higher is required to support symbolic names in assembly code */
> +#if (__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 1))

i assume theres no platform with arm and only gcc 2.95 ?


except these patch looks ok

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The greatest way to live with honor in this world is to be what we pretend
to be. -- Socrates
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