I have the following loop:
DO 20 J = JBGN, JEND
X(IROW) = X(IROW) - L(J)*X(JL(J))
When I compile it with ifort 13.1 the vec report shows the loop is vectorized, however when I use ifort 14.0 the vec-report reports that the loop cannot be vectorized. Both codes were compiled uisng the options: -xHost -O2 -vec-report6.
What is the reason ifort 14.0 doesn't vectorize this loop?