re PR middle-end/56727 (Recursive call goes through the PLT unnecessarily)

	PR tree-ssa/56727
	* gcc.dg/tree-ssa/pr56727.c: New testcase.
	* ipa-utils.c (recursive_call_p): Be more careful about interposition.

From-SVN: r245359

1 files changed, 16 insertions, 2 deletions

diff --git a/gcc/ipa-utils.c b/gcc/ipa-utils.c
index fc1ae1e..98a4f11 100644
--- a/gcc/ipa-utils.c
+++ b/gcc/ipa-utils.c
@@ -639,6 +639,20 @@ recursive_call_p (tree func, tree dest)
 {
   struct cgraph_node *dest_node = cgraph_node::get_create (dest);
   struct cgraph_node *cnode = cgraph_node::get_create (func);
-
-  return dest_node->semantically_equivalent_p (cnode);
+  ipa_ref *alias;
+  enum availability avail;
+
+  gcc_assert (!cnode->alias);
+  if (cnode != dest_node->ultimate_alias_target (&avail))
+    return false;
+  if (avail >= AVAIL_AVAILABLE)
+    return true;
+  if (!dest_node->semantically_equivalent_p (cnode))
+    return false;
+  /* If there is only one way to call the fuction or we know all of them
+     are semantically equivalent, we still can consider call recursive.  */
+  FOR_EACH_ALIAS (cnode, alias)
+    if (!dest_node->semantically_equivalent_p (alias->referring))
+      return false;
+  return true;
 }