Numba: High-Performance Python with CUDA Acceleration

Re:Numba: High-Performance Python with CUDA Acceleration by radarsat1 on Thursday September 21, 2017 @09:09AM (#15302948)

Your comment surprised me as clang is regarded to be pretty competitive these days (compared to gcc). I don't know the current state of things but a quick search revealed at least one sentence, http://llvm.org/docs/Vectorizers.html, "the loop below will be vectorized on Intel x86 if the SSE4.1 roundps instruction is available." So it seems SSE4 is supported by LLVM?

I was going to say maybe it's a new thing, but the following post also talks about SSE4 and is from 2011: http://blog.llvm.org/2011/12/llvm-31-vector-changes.html

Maybe it only supports a subset of SSE4? Do you know the details, compared to other compilers?

[ Parent | on HN ]

Re:Numba: High-Performance Python with CUDA Acceleration by fnl on Thursday September 21, 2017 @10:51AM (#15303982)

The source of my confusion is that the last time I looked into LLVM's SIMD support was in the context of looking at Rust, a bit more than a year ago or so, and back then my conclusion was that neither (Rust or LLVM, then in version 3) are very good tools for that. It seems I was very wrong, at least on the LLVM side.

EDIT: Sorry, to reply to your question, my concern is not GCC vs. clang; If you want max out your vector ops, I would suggest you should compare to ICC as the "standard", at least on Intel CPUs.

[ Parent | on HN ]

Re:Numba: High-Performance Python with CUDA Acceleration by radarsat1 on Thursday September 21, 2017 @01:42PM (#15305777)

Yep, I understand about icc. I actually wonder what is so difficult about optimising the way icc does, what does it actually do so much better than gcc? Anyone know of a good analysis?

[ Parent | on HN ]

Re:Numba: High-Performance Python with CUDA Acceleration by fnl on Thursday September 21, 2017 @02:49PM (#15306313)

I'd mostly attribute that to the MKL and their ability to just have to deal with their own instructions. But that's just an "educated guess".

[ Parent | on HN ]

Re:Numba: High-Performance Python with CUDA Acceleration by mattnewton on Thursday September 21, 2017 @08:42PM (#15308530)

Probably also having full time people working in the same company as the hardware guys who's job is to make the hardware look good.

[ Parent | on HN ]

Re:Numba: High-Performance Python with CUDA Acceleration by radarsat1 on Friday September 22, 2017 @09:36AM (#15312010)

I understand the social reasons, but I was wondering more about what compiler does in terms of technical achievements that goes beyond what gcc/clang can successfully generate. Surely this must be something that can be studied empirically.

[ Parent | on HN ]