Patch: -Wunreachable-bytecode

[Jan Hubicka]

> >>>>> "Per" == Per Bothner <per@bothner.com> writes:
> 
> Per> Why do we want to supress it?  Is it unreachable bytecode in
> Per> .class files generated by gcj?
> 
> Yes.  The appended file causes gcj to emit an unused instruction.

At -O0 we can generate unreachable code in some cases.  This can be
cared by calling cfg_cleanup unconditionally at bb_reorder time.

Honza
> 
> Tom
> 
> public class zt
> {
>   public boolean arrayEquals(Object[] o1, Object[] o2)
>   {
>     // We assume ordering is important.
>     for (int i = 0; i < o1.length; i++)
>       if (o1[i] instanceof Object[])
> 	{
> 	  if (o2[i] instanceof Object[]) 
> 	    {
> 	      if (!arrayEquals((Object[])o1[i], (Object[])o2[i]))
> 		return(false);
> 	    }
> 	  else
> 	    return(false);
> 	}
>       else
> 	if (!o1[i].equals(o2[i]))
> 	  return(false);
> 
>     return(true);
>   }
> }