The page at https://software.intel.com/en-us/node/524530 (Description of omp simd) has an example that is wrong (or weird) in two ways.
The example is
#pragma omp simd collapse(2)
for(i=0; i<N; i++) { a[i] = b[i] * c[i];
for(i=0; i<N; i++) { d[i] = e[i] * f[i]; }
}Firstly, that loop nest cannot be collapsed, since it is not perfectly nested.
Secondly the same loop variable is used in each loop, a definite bug!