linux下编程用 编译软件

				/* { dg-do compile } */ 				/* { dg-options "-O2 -fdump-tree-pre-stats" } */				double cos (double) __attribute__ ((const));				double sin (double) __attribute__ ((const));				double f(double a)				{				  double b;				  double c,d;				  double (*fp) (double) __attribute__ ((const));				  /* Fully redundant call, but we need a phi node to merge the results.  */				  if (a < 2.0)				    {				      fp = sin;				      c = fp (a);				    }				  else				    {				      c = 1.0; 				      fp = cos;				      c = fp (a);				    }				  d = fp (a);				  return d + c;				}								/* { dg-final { scan-tree-dump-times "Eliminated: 1" 1 "pre"} } */				/* { dg-final { cleanup-tree-dump "pre" } } */