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Re: [gomp4 simd, RFC] Simple fix to override vectorization cost estimation.

yes, ICC ignores cost analysis and follows user request on introduction of
simd parallelism in the loop.they follow the omp parallel semantics.

On Tue, Nov 12, 2013 at 3:05 PM, Jakub Jelinek <> wrote:
> On Tue, Nov 12, 2013 at 02:48:46PM +0400, Sergey Ostanevich wrote:
>> You are right regarding the cost model if we talk about vectorizer alone.
>> But the #pragma omp simd goes beyond the vectorizer - it introduces
>> parallel context in a place user defines, similar to #pragma omp parallel.
>> Are we applying any cost model for omp parallel region?
>> You can consider this pragma as a helper for developer for 'easily'
>> introduce parallelism in his code, hence any type of cost model -
>> whatever quality it is - will plays against this paradigm, forcing user
>> to play around our cost model to let it make the loop simd-parallel.
> So what do other compilers do here?  Does icc also totally ignore all
> cost analysis for #pragma omp simd or #pragma simd and vectorizes even when
> it would be obviously undesirable?
>         Jakub

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