[FFmpeg-devel] [PATCH] read_time() for SPARC
Fri Sep 10 18:08:33 CEST 2010
On Fri, Sep 10, 2010 at 01:32:07PM +0400, Michael Kostylev wrote:
> On Fri Sep 10 09:47:34 2010
> M?ns Rullg?rd wrote:
> >Yes, that instruction would be invalid there. In a pure 32-bit
> >environment, you can't use the high half of 64-bit registers, even if
> >they are physically present. Consider what happens on a context switch.
> An ancient kernel will not preserve the sse registers as well.
And it won't enable SSE either. Which has the additional advantage
that a kernel can avoid restoring and saving again the SSE state
if the program doesn't use it during its slice.
Handling CPU extensions with forward-, backward- and other
compatibility is one of the very few things where others
could take a lesson from x86.
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