[FFmpeg-devel] Inline ASM vs. Intrinsics

[Michael Niedermayer]

Hi

On Fri, May 11, 2007 at 02:07:38PM +0200, Luca Barbato wrote:
> Michael Niedermayer wrote:
> > 
> > just curious, how would asm make that more difficult?
> 
> altivec intrinsics:
> 
> 
> #include <vmx2spu.h>
> 
> [spu specific way to get data]
> 
> [former altivec code here, unchanged]
> 
> [spu specific way to push data]
> 
> 
> The altivec code would just build for spu thanks to the altivec/vmx ->
> spu mapping header.
> 
> asm :
> 
> reread what you wrote
> 
> rewrite it
> 
> Obviously you could refactor the code to use some spu-only constructs
> you may deem useful, BUT most of the code would remain the very same.

if every altivec instruction has a equivalent SPU instruction then its
more a matter of search and replace then reread and rewrite
if not then the altivec instrinsic code wont work on SPU either at least
not optimally with current gcc

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

it is not once nor twice but times without number that the same ideas make
their appearance in the world. -- Aristotle
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