The compiler may be able to perform additional optimizations if it is able to optimize across source line boundaries. These may include, but are not limited to, function inlining. This is enabled with the /Qipo option.
Rebuild the program using the /Qipo option to enable interprocedural optimization.
Select Optimization > Interprocedural Optimization > Multi-file(/Qipo)
Note that the vectorization messages now appear at the point of inlining in Driver.c (line 155).
Driver.c(145) (col. 2): remark: loop was not vectorized: not inner loop. Driver.c(155) (col. 3): remark: loop was not vectorized: not inner loop. Driver.c(155) (col. 3): remark: LOOP WAS VECTORIZED. Driver.c(164) (col. 2): remark: LOOP WAS VECTORIZED. Driver.c(54) (col. 2): remark: loop was not vectorized: not inner loop. Driver.c(55) (col. 3): remark: loop was not vectorized: vectorization possible but seems inefficient. Driver.c(60) (col. 3): remark: LOOP WAS VECTORIZED. Driver.c(69) (col. 2): remark: loop was not vectorized: vectorization possible but seems inefficient.
Now, run the executable and record the execution time.