News - AMD retires 3DNow! instruction set

[HEXUS]

Antiquated commands to be dropped from future processor designs.

Read more.

[aidanjt]

*sniffle* bye bye 3Dnotnow.

[Steve]

I've never looked at the 3DNow! instruction set, but I'd imagine it's very similar to SSE/MMX, so surely it wouldn't be that hard to patch compilers/assemblers to just translate 3DNow instructions into equivalent SSE instructions (or series of them for cases where there's no 1-1 mapping).

[kalniel]

There's a set of guidelines for porting to SSE here (pdf) see appendix A:
http://support.amd.com/us/Processor_TechDocs/26569.pdf

[Steve]

There's a set of guidelines for porting to SSE here (pdf) see appendix A:
http://support.amd.com/us/Processor_TechDocs/26569.pdf

Most of those could be dealt with quite easily at assembler level with instruction substitution, but a few would need extra instructions to deal with different rounding/truncating/numeric representation if they are to guarantee 3DNow-like behavour even in corner cases.

[Michael H]

Or they just run the Intel code path.

As Intel have never used 3DNow! I can't see there being any software that is heavily reliant on 3DNow! for performance - why cut off 80% of the market?

[Steve]

Or they just run the Intel code path.

As Intel have never used 3DNow! I can't see there being any software that is heavily reliant on 3DNow! for performance - why cut off 80% of the market?

Yes, I guess any software that doesn't properly detect 3DNow support or have an Intel code path is extremely bespoke. At least I'd hope so.