search for: seriosu

...insert movdq2q and movq2dq instructions as needed to copy the data (introduced in SSE2). If this is slow in current CPUs, then your code will be slow...but, if such code is being used in a performance critical location now, it really shouldn't be using MMX still, so I don't think this is a seriosu issue. For _mm_empty, I think the best thing to do is to follow what GCC did, and make it a no-op only if MMX is disabled, and have it continue to emit EMMS otherwise -- even though that is usually a waste. > 1. The calling convention problem; your description covers this. > > Well,...

I recently diagnosed a bug in someone else's software, which turned out to be due to incorrect MMX intrinsics usage: if you use any of the x86 intrinsics that accept or return __m64 values, then you, the *programmer* are required to call _mm_empty() before using any x87 floating point instructions or leaving the function. I was aware that this was required at the assembly-level, but not that