[Bug tree-optimization/57223] Auto-vectorization fails for nested multiple loops depending on type of array

[rguenth at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57223

--- Comment #7 from Richard Biener <rguenth at gcc dot gnu.org> ---
Testcase for the PRE issue:

typedef float test_t;
void foo(test_t * d, int n)
{
  int i, j, k;
  for (k=0; k<n; ++k) {
      for (i=0; i<n; ++i) {
          test_t t;
          j = k;
          t = d[i*n+k] + d[k*n+j];
          d[i*n+j] = (d[i*n+j] < t) ? d[i*n+j] : t;
          for (j=k+1; j<n; ++j) {
              t = d[i*n+k] + d[k*n+j];
              d[i*n+j] = (d[i*n+j] < t) ? d[i*n+j] : t;
          }
      }
  }
}

for which I think we have (simpler) duplicates.  We do not inhibit
PRE from removing partial memory redundancies just because we vectorize.