Hi,
I am experimenting with the auto vectorization functionality of Intel compiler. However, the following loop cannot be vectorized.
for (k=0; k < nz; k++) {
for (j=0; j < ny; j++) {
#pragma ivdep
for (i=0; i < nx; i++) {
ptr = i + j*nx + k*nx*ny;
p[ptr] = 1.0f + 0.1*drand48();
q[ptr] = 1.0f + 0.1*drand48();
}
}
}
In the program, both p and q are float arrays. The message I got for the loop from using -vec-report3 is:
remark: loop was not vectorized: existence of vector dependence
However, I cannot see any dependency in the loop. On the other hand, the loop can be vectorized if I don't use the random generator. So is it safe to say that loops with random generators cannot be vectorized?
