1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -fdump-tree-optimized" } */
       3  
       4  double a[10];
       5  int f(int n){
       6    a[3]=9;
       7    __builtin_memset(&a[n],3,sizeof(double));
       8    return a[3]==9;
       9  }
      10  
      11  /* { dg-final { scan-tree-dump " == 9" "optimized" } } */