[Ffmpeg-devel] [RFC] port cabac asm to AMD64

Reimar Döffinger Reimar.Doeffinger
Sat Oct 21 23:51:16 CEST 2006


Hello,
On Sat, Oct 21, 2006 at 03:33:00PM -0600, Loren Merritt wrote:
> On Sat, 21 Oct 2006, Reimar D?ffinger wrote:
> 
> >though it should be possible to optimize further, mixing use of 64 and
> >32 bit registers is said to be quite slow.
> 
> How so? My AMD optimization manual says that you _should_ mix 32bit and 
> 64bit registers, because there's no penalty and the 32bit opcodes are 
> smaller.
> (http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25112.PDF 
> page 68)

Maybe I confused that with access to 32 bit and 64 bit stuff at the same
memory address, that definitely had some problems.

Greetings,
Reimar D?ffinger




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