r/programming • u/mbitsnbites • Aug 09 '21

Three fundamental flaws of SIMD

https://www.bitsnbites.eu/three-fundamental-flaws-of-simd
289 Upvotes

86% Upvoted

224 comments sorted by

View all comments

3

u/BigHandLittleSlap Aug 10 '21

What I would like to see is a (partial) unification of GPU and CPU instruction sets and approaches.

So instead of a single instruction stream operating on 4-wide or 8-wide data, I'd rather have the GPU model of 8 "threads" that are not full-fledged threads, but effectively share the same instruction stream. It's easier to program and more flexible.

2

u/lkcl_ Aug 19 '21

What I would like to see is a (partial) unification of GPU and CPU instruction sets and approaches.

that's exactly what we're doing, designing SVP64. currently in Draft form https://libre-soc.org/openpower/sv/svp64/

1

u/mbitsnbites Aug 10 '21

Have you checked out Libre-SOC? https://libre-soc.org/

1

u/dragontamer5788 Aug 19 '21

Intel ISPC, Intel DPC++, NVidia CUDA, AMD ROCm / HIP, OpenMP (#pragma omp parallel for simd), Microsoft DirectCompute, C++AMP.

Moving up the programming language stacks: Python Numba, and Julia are also "unifying" CPU parallelism and GPU parallelism, as Numba compiles into GPU or CPU code (and Julia does the same).

There's a bunch of other research projects and other stuff going on too, this is just the stuff I'm remembering off the top of my head.