RFC re static chain and inlining

[kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)]

This relates to the message I sent earlier today to the GCC list.

The following patch fixes 38 ACATS tests, including c34007j.

It does so by treating static_chain_decl the same way the arguments are
handled, but I'm not sure that's correct, so I'd likesomebody who's more
familiar with this code than I to comment.

2004-07-24  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>

	* function.h (struct function): Add field saved_static_chain_decl.
	Fix comment for static_chain_decl.
	* tree-inline.c (save_body): Add new arg and handle static_chain_decl.
	* tree-inline.h (save_body): Add new arg.
	* tree-optimize.c (tree_rest_of_compilation): Handle saving
	static_chain_decl.

*** function.h	14 Jul 2004 07:30:15 -0000	1.129
--- function.h	24 Jul 2004 16:00:39 -0000
*************** struct function GTY(())
*** 174,177 ****
--- 174,178 ----
    tree saved_tree;
    tree saved_args;
+   tree saved_static_chain_decl;
  
    /* For function.c.  */
*************** struct function GTY(())
*** 255,259 ****
    HOST_WIDE_INT x_frame_offset;
  
!   /* A VAR_DECL that should contain the static chain for this function.
       It will be initialized at the beginning of the function.  */
    tree static_chain_decl;
--- 256,260 ----
    HOST_WIDE_INT x_frame_offset;
  
!   /* A PARM_DECL that should contain the static chain for this function.
       It will be initialized at the beginning of the function.  */
    tree static_chain_decl;
*** tree-inline.c	22 Jul 2004 19:01:03 -0000	1.130
--- tree-inline.c	24 Jul 2004 16:00:43 -0000
*************** clone_body (tree clone, tree fn, void *a
*** 1878,1885 ****
  }
  
! /* Save duplicate of body in FN.  MAP is used to pass around splay tree
!    used to update arguments in restore_body.  */
  tree
! save_body (tree fn, tree *arg_copy)
  {
    inline_data id;
--- 1878,1886 ----
  }
  
! /* Make and return duplicate of body in FN.  Put copies of DECL_ARGUMENTS
!    in *arg_copy and of the static chain, if any, in *sc_copy.  */
! 
  tree
! save_body (tree fn, tree *arg_copy, tree *sc_copy)
  {
    inline_data id;
*************** save_body (tree fn, tree *arg_copy)
*** 1905,1908 ****
--- 1906,1921 ----
      }
  
+   *sc_copy = DECL_STRUCT_FUNCTION (fn)->static_chain_decl;
+   if (*sc_copy)
+     {
+       tree new = copy_node (*sc_copy);
+ 
+       lang_hooks.dup_lang_specific_decl (new);
+       DECL_ABSTRACT_ORIGIN (new) = DECL_ORIGIN (*sc_copy);
+       insert_decl_map (&id, *sc_copy, new);
+       TREE_CHAIN (new) = TREE_CHAIN (*sc_copy);
+       *sc_copy = new;
+     }
+ 
    insert_decl_map (&id, DECL_RESULT (fn), DECL_RESULT (fn));
  
*** tree-inline.h	3 Jul 2004 00:15:43 -0000	1.11
--- tree-inline.h	24 Jul 2004 16:00:43 -0000
*************** Boston, MA 02111-1307, USA.  */
*** 27,34 ****
  void optimize_inline_calls (tree);
  bool tree_inlinable_function_p (tree);
! tree copy_tree_r (tree*, int*, void*);
! void clone_body (tree, tree, void*);
! tree save_body (tree, tree *);
! void remap_save_expr (tree*, void*, int*);
  int estimate_num_insns (tree expr);
  
--- 27,34 ----
  void optimize_inline_calls (tree);
  bool tree_inlinable_function_p (tree);
! tree copy_tree_r (tree *, int *, void *);
! void clone_body (tree, tree, void *);
! tree save_body (tree, tree *, tree *);
! void remap_save_expr (tree *, void *, int *);
  int estimate_num_insns (tree expr);
  
*** tree-optimize.c	22 Jul 2004 08:20:38 -0000	2.32
--- tree-optimize.c	24 Jul 2004 16:00:44 -0000
*************** tree_rest_of_compilation (tree fndecl, b
*** 519,523 ****
  	      cgraph_clone_inlined_nodes (e, true);
  	}
!       cfun->saved_tree = save_body (fndecl, &cfun->saved_args);
      }
  
--- 521,527 ----
  	      cgraph_clone_inlined_nodes (e, true);
  	}
!       cfun->saved_static_chain_decl = cfun->static_chain_decl;
!       cfun->saved_tree = save_body (fndecl, &cfun->saved_args,
! 				    &cfun->saved_static_chain_decl);
      }
  
*************** tree_rest_of_compilation (tree fndecl, b
*** 552,555 ****
--- 556,560 ----
        DECL_SAVED_TREE (fndecl) = cfun->saved_tree;
        DECL_ARGUMENTS (fndecl) = cfun->saved_args;
+       cfun->static_chain_decl = cfun->saved_static_chain_decl;
  
        /* When not in unit-at-a-time mode, we must preserve out of line copy