[FFmpeg-devel] [RFC] clobbers for XMM registers
Fri Oct 1 01:11:33 CEST 2010
On Thu, Sep 30, 2010 at 10:01:11AM -0400, Ronald S. Bultje wrote:
> 2010/9/28 M?ns Rullg?rd <mans at mansr.com>:
> > Michael Niedermayer <michaelni at gmx.at> writes:
> >> On Tue, Sep 28, 2010 at 09:36:40AM -0400, Ronald S. Bultje wrote:
> >>> On Tue, Sep 28, 2010 at 8:34 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >>> > you want to execute code from vp3dsp_sse2.c on a pre SSE cpu?
> >>> All _sse2 files are templates files that are included in dsputil_mmx.c
> >>> or similar.
> >> we could add the flags to dsputil_mmx then
> > That would allow the compiler to use SSE instructions in functions
> > that should be MMX only.
> I'm gonna start kicking this subject until it's solved. Come on guys,
> keep this moving. Why don't we make it (the clobbering) a macro and
> only enable this on x86-64. Don't forget all xmm registers are
> caller-save on x86-32 and x86-64 has no issues with marking clobbers
> (and even if it did, -msse is fine, there is no single x86-64 CPU that
> does not support SSE).
-msse is enabled by default on x86-64 (this is documented in the gcc docs).
i do not know what default it has on x86-32 on the various gcc versions
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
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