From 694cb3e1aa0163eba6e8130a5351ba66a0858207 Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Tue, 10 May 2011 08:45:00 +0000
Subject: [PATCH] 	Backported from mainline
 	2011-05-07  Zdenek Dvorak  <ook@ucw.cz>

	PR tree-optimization/48837
	* tree-tailcall.c (tree_optimize_tail_calls_1): Do not mark tailcalls
	when accumulator transformation is performed.

	* gcc.dg/pr48837.c: New testcase.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@173609 138bc75d-0d04-0410-961f-82ee72b054a4

index 99b02c2..83f2ff1 100644
new file mode 100644
index 0000000..ffc65b9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr48837.c
@@ -0,0 +1,30 @@
+/* PR tree-optimization/48837 */
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+void abort (void);
+
+__attribute__((noinline))
+int baz(void)
+{
+  return 1;
+}
+
+inline const int *bar(const int *a, const int *b)
+{
+ return *a ? a : b;
+}
+
+int foo(int a, int b)
+{
+   return a || b ? baz() : foo(*bar(&a, &b), 1) + foo(1, 0);
+}
+
+int main(void)
+{
+ if (foo(0, 0) != 2)
+   abort();
+
+ return 0;
+}
+
diff --git a/gcc/tree-tailcall.c b/gcc/tree-tailcall.c
index 85aa82b..e50ecc2 100644
--- a/gcc/tree-tailcall.c
+++ b/gcc/tree-tailcall.c
@@ -1019,6 +1019,14 @@ tree_optimize_tail_calls_1 (bool opt_tailcalls)
 					     integer_one_node);
     }
 
+  if (a_acc || m_acc)
+    {
+      /* When the tail call elimination using accumulators is performed,
+	 statements adding the accumulated value are inserted at all exits.
+	 This turns all other tail calls to non-tail ones.  */
+      opt_tailcalls = false;
+    }
+
   for (; tailcalls; tailcalls = next)
     {
       next = tailcalls->next;
-- 
1.7.0.4