Re: gcc vectorizer/auto-parallelizer

[Scott Robert Ladd <coyote at coyotegulch dot com>]

Thomas Veith wrote:
> Is there also someone working on an auto-parallelizer (this should be also 
> possible then)? Or is this feature not planned/impossible/uninteresting?

In my view, a GCC auto-parallelizer would likely be an extension of an 
explicit parallelization model, such as OpenMP.

A group -- GOMP -- exists to work on OpenMP extensions to GCC:

	http://savannah.nongnu.org/projects/gomp/

That group is largely dormant, for a variety of reasons. GOMP relies on 
tree-ssa (a pending change in GCC internal structures), and is likely to 
become more active after tree-ssa is merged with the mainline compiler 
in the near future.

At the moment, I'm busy with other projects, so I've pushed GOMP off my 
plate for the moment. However, having recently acquired both clients and 
hardware for which OpenMP is applicable, I expect to be getting back to 
GOMP in a month or so.

I've used auto-parallelizers, and have usually found them ineffective. 
Their best use is on old code that isn't practical to modify; for new 
code, explicit parallelization is usually the best course.

You can also got the MPI route (MPICH or LAM-MPI), if you're willing to 
use a message-passing model for manual parallelization.

--
Scott Robert Ladd
Coyote Gulch Productions (http://www.coyotegulch.com)
Software Invention for High-Performance Computing