C++ PATCH: Reduce memory usage when inlining

[Jason Merrill]

OK, that last patch broke libio, and I reverted it shortly after checking
it in; here's take 2.  The tree.c hunk is just something I noticed while
looking at this.

2000-05-01  Jason Merrill  <jason@casey.cygnus.com>

	* tree.c (build_target_expr_with_type): If we already have a
	TARGET_EXPR, just return it.

	* optimize.c (initialize_inlined_parameters): Don't generate an
	EXPR_STMT if we can just use DECL_INITIAL.
	* decl.c (emit_local_var): Only make the initialization a
	full-expression if stmts_are_full_exprs_p.

Index: tree.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/tree.c,v
retrieving revision 1.193
diff -c -p -r1.193 tree.c
*** tree.c	2000/04/11 17:29:54	1.193
--- tree.c	2000/05/01 23:45:45
*************** build_target_expr_with_type (init, type)
*** 294,299 ****
--- 294,302 ----
    tree slot;
    tree rval;
  
+   if (TREE_CODE (init) == TARGET_EXPR)
+     return init;
+ 
    slot = build (VAR_DECL, type);
    DECL_ARTIFICIAL (slot) = 1;
    DECL_CONTEXT (slot) = current_function_decl;
Index: optimize.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/optimize.c,v
retrieving revision 1.31
diff -c -p -r1.31 optimize.c
*** optimize.c	2000/05/01 16:51:17	1.31
--- optimize.c	2000/05/01 23:45:46
*************** initialize_inlined_parameters (id, args,
*** 429,449 ****
        splay_tree_insert (id->decl_map, 
  			 (splay_tree_key) p,
  			 (splay_tree_value) var);
        /* Initialize this VAR_DECL from the equivalent argument.  If
  	 the argument is an object, created via a constructor or copy,
  	 this will not result in an extra copy: the TARGET_EXPR
  	 representing the argument will be bound to VAR, and the
  	 object will be constructed in VAR.  */
!       init_stmt = build_min_nt (EXPR_STMT,
! 				build (INIT_EXPR, TREE_TYPE (p),
! 				       var, value));
!       /* Declare this new variable.  Note that we do this *after* the
! 	 initialization because we are going to reverse all the
! 	 initialization statements below.  */
!       TREE_CHAIN (init_stmt) = build_min_nt (DECL_STMT, var);
!       /* Add this initialization to the list.  */
!       TREE_CHAIN (TREE_CHAIN (init_stmt)) = init_stmts;
!       init_stmts = init_stmt;
      }
  
    /* The initialization statements have been built up in reverse
--- 429,458 ----
        splay_tree_insert (id->decl_map, 
  			 (splay_tree_key) p,
  			 (splay_tree_value) var);
+ 
+       /* Declare this new variable.  */
+       init_stmt = build_min_nt (DECL_STMT, var);
+       TREE_CHAIN (init_stmt) = init_stmts;
+       init_stmts = init_stmt;
+ 
        /* Initialize this VAR_DECL from the equivalent argument.  If
  	 the argument is an object, created via a constructor or copy,
  	 this will not result in an extra copy: the TARGET_EXPR
  	 representing the argument will be bound to VAR, and the
  	 object will be constructed in VAR.  */
!       if (! TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (p)))
! 	DECL_INITIAL (var) = value;
!       else
! 	{
! 	  init_stmt = build_min_nt (EXPR_STMT,
! 				    build (INIT_EXPR, TREE_TYPE (p),
! 					   var, value));
! 	  /* Add this initialization to the list.  Note that we want the
! 	     declaration *after* the initialization because we are going
! 	     to reverse all the initialization statements below.  */
! 	  TREE_CHAIN (init_stmt) = init_stmts;
! 	  init_stmts = init_stmt;
! 	}
      }
  
    /* The initialization statements have been built up in reverse
Index: decl.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/decl.c,v
retrieving revision 1.599
diff -c -p -r1.599 decl.c
*** decl.c	2000/05/01 06:01:33	1.599
--- decl.c	2000/05/01 23:45:57
*************** emit_local_var (decl)
*** 7871,7879 ****
      }
  
    /* Actually do the initialization.  */
!   expand_start_target_temps ();
    expand_decl_init (decl);
!   expand_end_target_temps ();
  }
  
  /* Finish processing of a declaration;
--- 7871,7883 ----
      }
  
    /* Actually do the initialization.  */
!   if (stmts_are_full_exprs_p)
!     expand_start_target_temps ();
! 
    expand_decl_init (decl);
! 
!   if (stmts_are_full_exprs_p)
!     expand_end_target_temps ();
  }
  
  /* Finish processing of a declaration;