Hi,
this patch enables bit more merging by clearing more flags that are
unnecesary and differ in practice across different copies of same ODR
types.
lto-bootstrapped/regtested x86_64-linux, OK?
* tree.c (fld_incomplete_type_of): Clear TREE_ADDRESSABLE flag.
(free_lang_data_in_decl): Set TREE_ADDRESSABLE for public functions
and variables; clear DECL_EXTERNAL, TYPE_DECL_SUPPRESS_DEBUG and
DECL_MODE on TYPE_DECLs.
Index: tree.c
===================================================================
--- tree.c (revision 265875)
+++ tree.c (working copy)
@@ -5197,6 +5197,7 @@ fld_incomplete_type_of (tree t, struct f
TYPE_SIZE_UNIT (copy) = NULL;
TYPE_CANONICAL (copy) = TYPE_CANONICAL (t);
TYPE_TYPELESS_STORAGE (copy) = 0;
+ TREE_ADDRESSABLE (copy) = 0;
if (AGGREGATE_TYPE_P (t))
{
TYPE_FIELDS (copy) = NULL;
@@ -5496,6 +5497,17 @@ free_lang_data_in_decl (tree decl, struc
if (TREE_CODE (decl) == FUNCTION_DECL)
{
struct cgraph_node *node;
+ /* Frontends do not set TREE_ADDRESSABLE on public variables even though
+ the address may be taken in other unit, so this flag has no practical
+ use for middle-end.
+
+ It would make more sense if frontends set TREE_ADDRESSABLE to 0 only
+ for public objects that indeed can not be adressed, but it is not
+ the case. Set the flag to true so we do not get merge failures for
+ i.e. virtual tables between units that take address of it and
+ units that don't. */
+ if (TREE_PUBLIC (decl))
+ TREE_ADDRESSABLE (decl) = true;
TREE_TYPE (decl) = fld_simplified_type (TREE_TYPE (decl), fld);
if (!(node = cgraph_node::get (decl))
|| (!node->definition && !node->clones))
@@ -5551,6 +5563,9 @@ free_lang_data_in_decl (tree decl, struc
}
else if (VAR_P (decl))
{
+ /* See comment above why we set the flag for functions. */
+ if (TREE_PUBLIC (decl))
+ TREE_ADDRESSABLE (decl) = true;
if ((DECL_EXTERNAL (decl)
&& (!TREE_STATIC (decl) || !TREE_READONLY (decl)))
|| (decl_function_context (decl) && !TREE_STATIC (decl)))
@@ -5560,8 +5575,12 @@ free_lang_data_in_decl (tree decl, struc
{
DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
DECL_VISIBILITY_SPECIFIED (decl) = 0;
+ /* TREE_PUBLIC is used to tell if type is anonymous. */
+ DECL_EXTERNAL (decl) = 0;
+ TYPE_DECL_SUPPRESS_DEBUG (decl) = 0;
DECL_INITIAL (decl) = NULL_TREE;
DECL_ORIGINAL_TYPE (decl) = NULL_TREE;
+ DECL_MODE (decl) = VOIDmode;
TREE_TYPE (decl) = void_type_node;
SET_DECL_ALIGN (decl, 0);
}
