Hi,
this patch makes inliner to handle removal of offline copies of functions in
the same comdat groups. Since aliases are now functions and a lot of comdat
functions do have aliases, we end up having a lot more comdat groups than
before.
Bootstrapped/regtested x86_64-linux, comitted.
Honza
* ipa-inline-transform.c (can_remove_node_now_p_1): Break out from...
(can_remove_node_now_p): ... here; handle same comdat groups.
(clone_inlined_nodes): Update use of can_remove_node_now_p add TODO.
(inline_call): Update use of can_remove_node_now_p.
Index: ipa-inline-transform.c
===================================================================
--- ipa-inline-transform.c (revision 174970)
+++ ipa-inline-transform.c (working copy)
@@ -83,7 +83,7 @@ update_noncloned_frequencies (struct cgr
copy of function was removed. */
static bool
-can_remove_node_now_p (struct cgraph_node *node)
+can_remove_node_now_p_1 (struct cgraph_node *node)
{
/* FIXME: When address is taken of DECL_EXTERNAL function we still
can remove its offline copy, but we would need to keep unanalyzed node in
@@ -98,15 +98,34 @@ can_remove_node_now_p (struct cgraph_nod
&& (!DECL_VIRTUAL_P (node->decl)
|| (!DECL_COMDAT (node->decl)
&& !DECL_EXTERNAL (node->decl)))
- /* Don't reuse if more than one function shares a comdat group.
- If the other function(s) are needed, we need to emit even
- this function out of line. */
- && !node->same_comdat_group
/* During early inlining some unanalyzed cgraph nodes might be in the
callgraph and they might reffer the function in question. */
&& !cgraph_new_nodes);
}
+/* We are going to eliminate last direct call to NODE (or alias of it) via
edge E.
+ Verify that the NODE can be removed from unit and if it is contained in
comdat
+ group that the whole comdat group is removable. */
+
+static bool
+can_remove_node_now_p (struct cgraph_node *node, struct cgraph_edge *e)
+{
+ struct cgraph_node *next;
+ if (!can_remove_node_now_p_1 (node))
+ return false;
+
+ /* When we see same comdat group, we need to be sure that all
+ items can be removed. */
+ if (!node->same_comdat_group)
+ return true;
+ for (next = node->same_comdat_group;
+ next != node; next = next->same_comdat_group)
+ if (node->callers && node->callers != e
+ && !can_remove_node_now_p_1 (node))
+ return false;
+ return true;
+}
+
/* E is expected to be an edge being inlined. Clone destination node of
the edge and redirect it to the new clone.
@@ -128,8 +147,15 @@ clone_inlined_nodes (struct cgraph_edge
/* Recursive inlining never wants the master clone to
be overwritten. */
&& update_original
- && can_remove_node_now_p (e->callee))
+ && can_remove_node_now_p (e->callee, e))
{
+ /* TODO: When callee is in a comdat group, we could remove all of it,
+ including all inline clones inlined into it. That would however
+ need small function inlining to register edge removal hook to
+ maintain the priority queue.
+
+ For now we keep the ohter functions in the group in program until
+ cgraph_remove_unreachable_functions gets rid of them. */
gcc_assert (!e->callee->global.inlined_to);
if (e->callee->analyzed && !DECL_EXTERNAL (e->callee->decl))
{
@@ -200,7 +226,7 @@ inline_call (struct cgraph_edge *e, bool
while (alias && alias != callee)
{
if (!alias->callers
- && can_remove_node_now_p (alias))
+ && can_remove_node_now_p (alias, e))
{
next_alias = cgraph_alias_aliased_node (alias);
cgraph_remove_node (alias);
