[LLVMdev] SPMD Autovectorizer (original) (raw)

Pekka Jääskeläinen pekka.jaaskelainen at tut.fi
Tue Jul 7 11:19:35 PDT 2015

On 07/07/2015 01:32 PM, Renato Golin wrote:

Wouldn't OpenMP account for some of that? At least on a single machine, could you have both parallel and simd optimisations done on the same loop?

The point in SPMD program description (e.g. CUDA or OpenCL C) autovectorization is to produce something like OpenMP parallel loops or SIMD pragmas automatically from the single thread/WI description, adhering to its barrier synchronization semantics etc.

That is, the output of this pass could be also converted to OpenMP SIMD constructs, if wanted. In pocl's case the output is simply a new kernel function (we call "work group function") that executes all WIs using parallel loops (which can be autovectorized more easily, or even multithreaded if seeing fit, or both).

-- --Pekka

More information about the llvm-dev mailing list