Wrap fewer refs for LTO

[Richard Biener]

On Wed, 9 Dec 2015, Jan Hubicka wrote:

> > Hi,
> > while debugging an renaming issue I run into ADDR_EXPR of MEM_REF of ADDR_EXPR
> > which seemed somewhat odd + we don't really get the CONSTANT and other flags
> > right because recompute_tree_invariant_for_addr_expr punts on ADDR_EXPR inside
> > ADDR_EXPR.
> > 
> > The expression is created by wrap_refs. While looking at the code I noitced that
> > we wrap all VAR_DECLs while I think we only need to wrap ones that can be merged
> > by lto-symtab.
> > 
> > I wonder if the function could not stop the recursive walk on ADDR_EXPR and MEM_REFS?
> > Is there a way we can use the inner MEM_REF for something useful?
> > 
> > Bootstrapped/regtested x86_64-linux, OK?
> 
> Uh, sorry, actually I forgot about DECL_EXTERNAL. Here is updated version I am re-testing.

OK.

> 	* lto-streamer-out.c (wrap_refs): Only wrap public variables.
> Index: lto-streamer-out.c
> ===================================================================
> --- lto-streamer-out.c	(revision 231438)
> +++ lto-streamer-out.c	(working copy)
> @@ -2236,7 +2237,9 @@ wrap_refs (tree *tp, int *ws, void *)
>  {
>    tree t = *tp;
>    if (handled_component_p (t)
> -      && TREE_CODE (TREE_OPERAND (t, 0)) == VAR_DECL)
> +      && TREE_CODE (TREE_OPERAND (t, 0)) == VAR_DECL
> +      && (TREE_PUBLIC (TREE_OPERAND (t, 0))
> +	   || DECL_EXTERNAL (TREE_OPERAND (t, 0))))
>      {
>        tree decl = TREE_OPERAND (t, 0);
>        tree ptrtype = build_pointer_type (TREE_TYPE (decl));
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)