--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/pr43864-2.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,22 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */
+
+int
+f (int c, int b, int d)
+{
+  int r, e;
+
+  if (c)
+    r = b + d;
+  else
+    {
+      e = b + d;
+      r = e;
+    }
+
+  return r;
+}
+
+/* { dg-final { scan-tree-dump-times "if " 0 "pre"} } */
+/* { dg-final { scan-tree-dump-times "(?n)_.*\\+.*_" 1 "pre"} } */
+/* { dg-final { scan-tree-dump-not "Invalid sum" "pre"} } */