The Dependencies analysis shows there is no real dependency in the loop for the given workload. Tell the compiler it is safe to vectorize using the restrict keyword or a directive:
| Directive | Outcome |
|---|---|
| !$OMP SIMD | Ignores all dependencies in the loop |
| !DIR$ IVDEP | Ignores only vector dependencies (which is safest) |
!DIR$ IVDEP
...!DIR$ IVDEP
do i = 1, N-4, 4
a(i+4) = b(i) * c
enddo