I don't have any experience with that aspect of openmp. When you use ISPC are you using the varying and uniform keywords? You can write something that is almost C but it basically forced to vectorize.
If you both are vectorizing the same thing there might not be much difference.
If both are not vectorizing there might not be much difference, but with ISPC you can easily make sure that it does use vectorization and the best instruction set for your CPU.
If you both are vectorizing the same thing there might not be much difference.
If both are not vectorizing there might not be much difference, but with ISPC you can easily make sure that it does use vectorization and the best instruction set for your CPU.