On 04/24/13 01:01, Jakub Jelinek wrote:
The documentation doesn't suggest that. Anyway, so #pragma simd should be equivalent to #pragma omp simd wrt. inter-iteration dependencies, and #pragma simd vectorlength(a, b, c) to #pragma omp simd safelen(max (a, b, c)) ? If so, then the FE could emit OMP_SIMD for #pragma simd, and if vectorlength is present, add OMP_CLAUSE_SAFELEN with the maximum of the values in all vectorlength clauses, and keep the vectorlength clauses around too as CILK_CLAUSE_VECTORLENGTH as hints to the vectorizer?
I can make these changes to the Cilk Plus code.
Also, Aldy said that #pragma simd loops allow != condition, how do you compute number of iterations in that case if the increment isn't constant? As conditional depending on whether increment is positive or negative? != condition isn't allowed in OpenMP, so there it is always obvious which direction it should iterate, and the expansion code will assume if it sees NE_EXPR that it is just folded border test (comparison with maximum or minimum value).
Perhaps it is an oversight in the documentation, because icc disallows both == and !=. Disallowing != makes it a lot easier :).
