There is a very informative youtube video by James Reinders about vectorization.
https://www.youtube.com/watch?v=hyZMssi_gZY
In it, he mentions two pragmas – ivdep and omp simd – which force vectorization under different circumstances.
Since Reinders works for Intel I suspect these pragmas are valid for the intel C compiler. Are they also valid for gcc?
In addition, if omp simd is valid for gcc and if I use
#pragma omp simd
with gcc do I have to use -fopenmp as a commandline option for the compulation?