gcc/testsuite/gcc.dg/tree-ssa/pr107732.c

// { dg-do compile }
// { dg-options "-O2" }

double sqrt(double);
double a, b, c;
void d() {
  for (;;) {
    c = __builtin_fabs(a);
    sqrt(c);
    if (a)
      a = b;
  }
}