Vectorizer Pragmas

Tim Prince n8tm@aol.com
Mon Feb 17 14:47:00 GMT 2014


On 2/17/2014 4:42 AM, Renato Golin wrote:
> On 16 February 2014 23:44, Tim Prince <n8tm@aol.com> wrote:
>> I don't think many people want to use both OpenMP 4 and older Intel
>> directives together.
> I'm having less and less incentives to use anything other than omp4,
> cilk and whatever. I think we should be able to map all our internal
> needs to those pragmas.
>
> On the other hand, if you guys have any cross discussion with Intel
> folks about it, I'd love to hear. Since our support for those
> directives are a bit behind, would be good not to duplicate the
> efforts in the long run.
>
>
I'm continuing discussions with former Intel colleagues.  If you are 
asking for insight into how Intel priorities vary over time, I don't 
expect much, unless the next beta compiler provides some inferences.  
They have talked about implementing all of OpenMP 4.0 except user 
defined reduction this year.  That would imply more activity in that 
area than on cilkplus, although some fixes have come in the latter.  On 
the other hand I had an issue on omp simd reduction(max: ) closed with 
the decision "will not be fixed."
I have an icc problem report in on fixing omp simd safelen so it is more 
like the standard and less like the obsolete pragma simd vectorlength.  
Also, I have some problem reports active attempting to get clarification 
of their omp target implementation.

You may have noticed that omp parallel for simd in current Intel 
compilers can be used for combined thread and simd parallelism, 
including the case where the outer loop is parallelizable and 
vectorizable but the inner one is not.

-- 
Tim Prince



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