[tree-ssa Too many edges in CFG

[law at redhat dot com]

Andrew & Diego pointed out two goofs in my code to support EH for
the tree-ssa branch.  In both cases we're creating unnecessary
edges.

First, we were creating a fall-thru edge for a block which ends
with a volatile call.  Opps.

Second, we tried to create a duplicate edge for functions which
receive non-local gotos.

This patch fixes both issues.

	* tree-cfg.c (make_exit_edges): Fix handling of blocks which
	end with calls.

Index: tree-cfg.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-cfg.c,v
retrieving revision 1.1.4.82
diff -c -3 -p -r1.1.4.82 tree-cfg.c
*** tree-cfg.c	6 May 2003 17:56:12 -0000	1.1.4.82
--- tree-cfg.c	7 May 2003 02:44:58 -0000
*************** make_exit_edges (bb)
*** 1127,1141 ****
        /* A CALL_EXPR node here means that the last statement of the block
  	 is a call to a non-returning function or a call that may throw.  */
      case CALL_EXPR:
!       /* Some calls are known not to return, so we just need to make
! 	 an edge from them to the exit block.  */
!       if (call_expr_flags (last) & (ECF_NORETURN | ECF_LONGJMP))
! 	make_edge (bb, EXIT_BLOCK_PTR, 0);
        if (FUNCTION_RECEIVES_NONLOCAL_GOTO (current_function_decl))
! 	{
! 	  make_goto_expr_edges (bb);
!           make_edge (bb, successor_block (bb), 0);
! 	}
        
        /* If this statement has reachable exception handlers, then
  	 create abnormal edges to them.  */
--- 1127,1137 ----
        /* A CALL_EXPR node here means that the last statement of the block
  	 is a call to a non-returning function or a call that may throw.  */
      case CALL_EXPR:
!       /* If this function receives a nonlocal goto, then we need to
! 	 make edges from this call site to all the nonlocal goto
! 	 handlers.  */
        if (FUNCTION_RECEIVES_NONLOCAL_GOTO (current_function_decl))
! 	make_goto_expr_edges (bb);
        
        /* If this statement has reachable exception handlers, then
  	 create abnormal edges to them.  */
*************** make_exit_edges (bb)
*** 1147,1152 ****
--- 1143,1157 ----
  	       t;
  	       t = TREE_CHAIN (t))
  	    make_edge (bb, first_exec_block (&TREE_VALUE (t)), EDGE_ABNORMAL);
+ 	}
+ 
+       /* Some calls are known not to return.  For such calls we need to
+ 	 add an edge to the exit block.  No fall thru edge is needed
+ 	 as these calls can not return in the normal sense.  */
+       if (call_expr_flags (last) & (ECF_NORETURN | ECF_LONGJMP))
+ 	{
+ 	  make_edge (bb, EXIT_BLOCK_PTR, 0);
+ 	  return;
  	}
  
        /* Don't forget the fall-thru edge.  */