Diagnostic 15319: loop was not vectorized: novector directive used

Cause:

This vectorization diagnostic states that the loop is annotated with #pragma novector and thus the loop is not vectorized.

Example:

void foo(double *a, int N){
  int i; 
#pragma novector 
  for(i=0;i<N;i++){ 
    a[i] *= 2; 
  } 
}

$ icpc test31.cc -c -qopt-report2 -qopt-report-phase=vec -qopt-report-file=stderr

Begin optimization report for: foo(double *, int)

    Report from: Vector optimizations [vec]

LOOP BEGIN at test31.cc(4,3)
   remark #15319: loop was not vectorized: novector directive used
LOOP END

LOOP BEGIN at test31.cc(4,3)
<Remainder>
LOOP END