Product Version:Intel® Fortran Compiler 15.0 and above
The vectorization report generated when using Intel® Fortran Compiler's optimization options (/O2 /Qopt-report:2) states that loop was not vectorized since loop body became empty after optimizations.
An example below will generate the following remark in optimization report:
integer function foo(a, b, n) implicit none integer, intent(in) :: n real, intent(inout) :: a real, intent (in) :: b integer :: i do i=1,n a = b + 1 end do foo = a end function
In the example above, there is only one expression inside the loop. When moved outside the loop as a result of the compiler's optimization process there is nothing else left inside the loop to vectorize.