Which compiler options did you set to get this report? vec-report level has to be increased to 2 or 3 to get the compiler to report on loops which are considered, or opt-report may have to be set.
Which loop syntax?  I frequently have to turn loops into a for(;i<last;++i) form,  to get them considered as candidates.
The compiler will not attempt loop interchange and the like, so as to make stride 1 loops inner, unless -O3 is set.     icpc also is more dependent on the restrict extension than some others, in the case where it is not a reduction operation (such as inner_product).