[tree-ssa] insert before and out-of-ssa patchlets

[Andrew MacLeod <amacleod at redhat dot com>]

I've commited the following patch. Its fixes 2 bugs in insert_before and
a bug in the out-of-ssa algorithm which was causing too many copies to
be inserted.

Andrew

	* tree-cfg.c (bsi_insert_before): Update end of block pointer if we
	inserted before the last stmt in a block. (The container changed).
	* tree-ssa.c (elim_backward): Inserting copy should be within 
	conditional check.
	(elim_create): Only select one bit instead of the all.

Index: tree-cfg.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-cfg.c,v
retrieving revision 1.1.4.96
diff -c -p -r1.1.4.96 tree-cfg.c
*** tree-cfg.c	24 May 2003 13:08:50 -0000	1.1.4.96
--- tree-cfg.c	2 Jun 2003 13:43:23 -0000
*************** bsi_insert_before (curr_bsi, t, mode)
*** 3553,3564 ****
    tsi_link_before (&inserted_tsi, t, TSI_NEW_STMT);
    add_stmt_to_bb (tsi_container (inserted_tsi), curr_bb, parent);
  
-   same_tsi = inserted_tsi;
-   tsi_next (&same_tsi);
- 
    if (curr_container == curr_bb->head_tree_p)
      {
!       curr_bb->head_tree_p = tsi_container (same_tsi);
        /* If the parent block is a COND_EXPR or LOOP_EXPR, check if this
  	 is the block which they point to and update if necessary.  */
        if (parent)
--- 3553,3561 ----
    tsi_link_before (&inserted_tsi, t, TSI_NEW_STMT);
    add_stmt_to_bb (tsi_container (inserted_tsi), curr_bb, parent);
  
    if (curr_container == curr_bb->head_tree_p)
      {
!       curr_bb->head_tree_p = tsi_container (inserted_tsi);
        /* If the parent block is a COND_EXPR or LOOP_EXPR, check if this
  	 is the block which they point to and update if necessary.  */
        if (parent)
*************** bsi_insert_before (curr_bsi, t, mode)
*** 3584,3589 ****
--- 3581,3596 ----
  	    }
  	}
      }
+ 
+   same_tsi = inserted_tsi;
+   tsi_next (&same_tsi);
+ 
+   /* The end block pointer can be modified when we insert before the last stmt
+      in a block.  This occurs because we insert a new container for the last
+      stmt.  */
+ 
+   if (curr_container == curr_bb->end_tree_p)
+     curr_bb->end_tree_p = tsi_container (same_tsi);
  
    if (mode == BSI_SAME_STMT)
      bsi_update_from_tsi (curr_bsi, same_tsi);
Index: tree-ssa.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/Attic/tree-ssa.c,v
retrieving revision 1.1.4.83
diff -c -p -r1.1.4.83 tree-ssa.c
*** tree-ssa.c	29 May 2003 23:10:59 -0000	1.1.4.83
--- tree-ssa.c	2 Jun 2003 13:43:24 -0000
*************** elim_backward (g, T)
*** 1071,1080 ****
    EXECUTE_IF_SET_IN_BITMAP (g->pred[T], 0, P,
      {
        if (!TEST_BIT (g->visited, P))
!         elim_backward (g, P);
!       insert_copy_on_edge (g->e, 
! 			   partition_to_var (g->map, P), 
! 			   partition_to_var (g->map, T));
      });
  }
  
--- 1071,1082 ----
    EXECUTE_IF_SET_IN_BITMAP (g->pred[T], 0, P,
      {
        if (!TEST_BIT (g->visited, P))
!         {
! 	  elim_backward (g, P);
! 	  insert_copy_on_edge (g->e, 
! 			       partition_to_var (g->map, P), 
! 			       partition_to_var (g->map, T));
! 	}
      });
  }
  
*************** elim_create (g, T)
*** 1105,1118 ****
      }
    else
      {
!       EXECUTE_IF_SET_IN_BITMAP (g->succ[T], 0, S,
  	{
  	  SET_BIT (g->visited, T);
  	  insert_copy_on_edge (g->e, 
  			       partition_to_var (g->map, T), 
  			       partition_to_var (g->map, S));
! 	});
!       bitmap_clear (g->succ[T]);
      }
    
  }
--- 1107,1121 ----
      }
    else
      {
!       S = bitmap_first_set_bit (g->succ[T]);
!       if (S != -1)
  	{
  	  SET_BIT (g->visited, T);
+ 	  bitmap_clear_bit (g->succ[T], S);
  	  insert_copy_on_edge (g->e, 
  			       partition_to_var (g->map, T), 
  			       partition_to_var (g->map, S));
! 	}
      }
    
  }