diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d6cd5690686..7dfe5f49b32 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2010-11-24  Richard Guenther  <rguenther@suse.de>
+
+	PR lto/43218
+	* lto-symtab.c (lto_cgraph_replace_node): Mark edges with
+	conflicting function signatures as non-inlineable.
+
 2010-11-24  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/46614
diff --git a/gcc/lto-symtab.c b/gcc/lto-symtab.c
index b83c75e9da7..4484d93f0a2 100644
--- a/gcc/lto-symtab.c
+++ b/gcc/lto-symtab.c
@@ -210,6 +210,7 @@ lto_cgraph_replace_node (struct cgraph_node *node,
 {
   struct cgraph_edge *e, *next;
   bool no_aliases_please = false;
+  bool compatible_p;
 
   if (cgraph_dump_file)
     {
@@ -240,10 +241,19 @@ lto_cgraph_replace_node (struct cgraph_node *node,
     }
 
   /* Redirect all incoming edges.  */
+  compatible_p
+    = gimple_types_compatible_p (TREE_TYPE (TREE_TYPE (prevailing_node->decl)),
+				 TREE_TYPE (TREE_TYPE (node->decl)), GTC_DIAG);
   for (e = node->callers; e; e = next)
     {
       next = e->next_caller;
       cgraph_redirect_edge_callee (e, prevailing_node);
+      /* If there is a mismatch between the supposed callee return type and
+	 the real one do not attempt to inline this function.
+	 ???  We really need a way to match function signatures for ABI
+	 compatibility and perform related promotions at inlining time.  */
+      if (!compatible_p)
+	e->call_stmt_cannot_inline_p = 1;
     }
   /* Redirect incomming references.  */
   ipa_clone_refering (prevailing_node, NULL, &node->ref_list);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index feae590deca..475df8f7bf5 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-11-24  Richard Guenther  <rguenther@suse.de>
+
+	PR lto/43218
+	* gcc.dg/lto/20100423-1_0.c: Enable for all LTO modes.
+
 2010-11-24  Jakub Jelinek  <jakub@redhat.com>
 
 	PR rtl-optimization/46614
diff --git a/gcc/testsuite/gcc.dg/lto/20100423-1_0.c b/gcc/testsuite/gcc.dg/lto/20100423-1_0.c
index eb931651500..1963c1fee17 100644
--- a/gcc/testsuite/gcc.dg/lto/20100423-1_0.c
+++ b/gcc/testsuite/gcc.dg/lto/20100423-1_0.c
@@ -1,5 +1,4 @@
 /* { dg-lto-do run } */
-/* { dg-lto-options {{-O2 -flto -flto-partition=none}} } */
 
 struct bar {int x;};
 extern struct bar foo(void);