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Did any builds ever take advantage of mmx and sse?

PostPosted: Sun Jul 30, 2017 4:04 pm
by invictius
And for that matter, what was the first build to utilize sse2? Obviously couldn't have been before late 2000 (first pentium 4 released)

Re: Did any builds ever take advantage of mmx and sse?

PostPosted: Sun Jul 30, 2017 4:18 pm
by Graf Zahl
Hardly interesting. It only ever got used for a small number (two to be precise) of data generation functions and one low level function in the node builder. None of this ever had any significant impact on performance.

Re: Did any builds ever take advantage of mmx and sse?

PostPosted: Mon Oct 23, 2017 1:09 pm
by Csonicgo
The issue with MMX is that there really isn't a good way to take advantage of SIMD optimizations in such a serial manner - and any thing that MMX could be used for was handled by DirectX at that time, which used MMX already out of the gate. Plus, MMX works best when there is a steady stream of data, which Doom constantly shifts around by flying through the BSP as the player moves, turns around, etc -- there's just no good way to go about it.

Basically MMX works best when there are no surprises, and Doom is a game, not a video/audio file.