[Ffmpeg-devel] mmx/sse optimizations
Fri Dec 23 08:38:42 CET 2005
Rich Felker wrote:
>> SIMD code is a different beast than normal ASM. I think this tool
>> has its place. Perhaps another idea would be a tool that enables the user
>>to describe some kind of general algorithm with a set of SIMD-like
>> Then the tool decides what the equivalent code would look
>>like using different SIMD sets (MMX, SSE2, AltiVec) AND can output the
>>correct ASM syntax for use in gcc and MSVC.
> Hmm, sounds a lot like vector intrinsics. IMO they're a trap that lead
> to people making simd code that's 5-25% slower than handwritten asm.
Prove it on non flawed SIMD and non flawed CC. I'm quite sure nobody
will get a schedule right for each cpu. The problem is that gcc +
mmx_intrinsics == boom ...
Gentoo/linux Developer Gentoo/PPC Operational Leader
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