用于进行gcc测试

				/* { dg-do compile } */				/* { dg-options "-O1 -fno-tree-vrp -fno-tree-copy-prop -fno-tree-ccp -fdump-tree-optimized" } */												volatile int x;								int main ()				{				  volatile int *vip;				  vip = &x;				  volatile int *cvip;				  cvip = vip;								  if (vip != cvip) return -1;				  return 0;				}								/* { dg-final { scan-tree-dump-times "return 0" 1 "optimized" } } */				/* { dg-final { cleanup-tree-dump "optimized" } } */