[Bug tree-optimization/71824] [6/7 Regression] ICE when compiling libiberty with Graphite loop optimizations

[drfiemost at email dot it]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71824

--- Comment #7 from Leandro Nini <drfiemost at email dot it> ---
Reduced testcase, ICEs with gcc -O2 -floop-interchange:

int a, b, d;
int **c;
int fn1() {
  while (a)
    if (d) {
      int e = -d;
      for (; b < e; b++)
        c[b] = &a;
    } else {
      for (; b; b++)
        c[b] = &b;
      d = 0;
    }
}