[tree-ssa] Convert fold's result

[law at redhat dot com]

This fixes 20030917-3.c.  In a nutshell, we're missing optimization
opportunities because the RHS type is a integer type and the RESULT
type is boolean.  Converting the result to the RHS's type makes everything
happy.

        * tree-ssa-ccp.c (ccp_fold): If the return value has the wrong
        type, try to convert it to the proper type rather than failing.
 

Index: tree-ssa-ccp.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa-ccp.c,v
retrieving revision 1.1.2.90
diff -c -3 -p -r1.1.2.90 tree-ssa-ccp.c
*** tree-ssa-ccp.c	16 Sep 2003 23:46:38 -0000	1.1.2.90
--- tree-ssa-ccp.c	18 Sep 2003 03:19:55 -0000
*************** ccp_fold (tree stmt)
*** 841,850 ****
    else
      return rhs;
  
!   /* If we got a simplified form and the type of the simplified form
!      is the same type as the original, then return the simplified form.  */
!   if (retval && TREE_TYPE (retval) == TREE_TYPE (rhs))
!     return retval;
  
    /* No simplification was possible.  */
    return rhs;
--- 841,855 ----
    else
      return rhs;
  
!   /* If we got a simplified form, see if we need to convert its type.  */
!   if (retval)
!     {
!       if (TREE_TYPE (retval) != TREE_TYPE (rhs))
! 	retval = convert (TREE_TYPE (rhs), retval);
! 
!       if (TREE_TYPE (retval) == TREE_TYPE (rhs))
! 	return retval;
!     }
  
    /* No simplification was possible.  */
    return rhs;