[FFmpeg-devel] [PATCH] Disable MSA optimization for big endian arch

Michael Niedermayer michael at niedermayer.cc
Fri May 19 22:26:58 EEST 2017

On Thu, May 18, 2017 at 12:36:51PM +0000, Shivraj Patil wrote:
> Shivraj: yes, -mmsa flag will be added and should not be an issue for big endian mips builds.
> > +    if enabled bigendian && enabled msa; then
> > +        disable msa
> > +    fi
> As currently, MSA optimizations does not support big endian, above code will disable MSA and switch to default C functions.

So IIUC the CPU that is build for supports MSA but its not big endian
and our hand written MSA code depends on the cpu being big endian ?

then i think its more correct to leave MSA enabled and put the code
under #if HAVE_BIGENDIAN (or some other solution)

using MSA to mean MSA on either endianness in some part of configure
and otherwise have MSA mean MSA only on big endian in other parts is
a recipe for alot of confusion

Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Let us carefully observe those good qualities wherein our enemies excel us
and endeavor to excel them, by avoiding what is faulty, and imitating what
is excellent in them. -- Plutarch
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