POV-Ray : Newsgroups : povray.programming : AVX2 benefits for Povray? Server Time: 19 Aug 2019 14:21:36 GMT
  AVX2 benefits for Povray? (Message 1 to 2 of 2)  
From: jhu
Subject: AVX2 benefits for Povray?
Date: 2 Aug 2012 18:35:00
Message: <web.501ac6f62ad0663919d10cf70@news.povray.org>
What are your thoughts on this? The upcoming AVX2 instructions have
gather/scatter and integer support which should make autovectorization easier.
Do you think Povray will be able to gain appreciable performance from this?
Would Povray benefit (if at all) from gather/scatter?


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From: Thomas Willhalm
Subject: Re: AVX2 benefits for Povray?
Date: 16 Dec 2013 23:30:00
Message: <web.52af8cd6d04decc5228c4210@news.povray.org>
"jhu" <nomail@nomail> wrote:
> What are your thoughts on this? The upcoming AVX2 instructions have
> gather/scatter and integer support which should make autovectorization easier.
> Do you think Povray will be able to gain appreciable performance from this?
> Would Povray benefit (if at all) from gather/scatter?

One probably needs to have a closer look. "gather" is not a very fast
instruction on Haswell architecture. "scatter" will only be available with Intel
AVX-512 instructions. In case you are hoping to compute a ray in each vector
element, this won't work for complex scenes: Vectorization and branches don't
work well together and each object intersection might result in different
branches. If at all, I would rather hope for acceleration of individual
routines, e.g. subsurface scattering.


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