1  /* { dg-do compile } */
       2  /* { dg-options "-O1 -fvariable-expansion-in-unroller -funroll-loops -fcompare-debug" } */
       3  
       4  int sum(int *buf, int len)
       5  {
       6    int s = 0;
       7    while (--len > 0) s += *buf++;
       8    return s;
       9  }