Advanced Micro Devices Inc (AMD)

[dacaw]

Vendor specific code

That's the beauty of plug-ins. You can let the user specify what processor they have. In fact my code checks the CPUID and determines which are valid choices so a k6 user can't specify SSE for example.

I did 3 versions from one codebase:

3dnow/MMX for k6
3dnow/MMX enhanced for athlon
3dnow/SSE/MMX for athlon xp
MMX for intel chips (less accurate)
someone else did an x87 version that was as accurate as my 3dnow but much, much slower.

This was highly time critical code. An early version became part of DivX but then they went proprietary. I don't know what they use there now.

I liked 3DNow except for one thing: you couldn't specify the rounding mode and it was not defined as part of the standard.