diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index e767db3d2ca8..0cb33a0a0469 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2010-09-27  Hans-Peter Nilsson  <hp@axis.com>
+
+	* emit-rtl.c (reorder_insns_nobb) [ENABLE_CHECKING]: Sanity-check
+	that AFTER is not in the range FROM..TO, inclusive.
+
 2010-09-27  Hans-Peter Nilsson  <hp@axis.com>
 	    Bernd Schmidt  <bernds@codesourcery.com>
 
diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index 35a4360c973a..16032e94044b 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -3977,6 +3977,13 @@ delete_insns_since (rtx from)
 void
 reorder_insns_nobb (rtx from, rtx to, rtx after)
 {
+#ifdef ENABLE_CHECKING
+  rtx x;
+  for (x = from; x != to; x = NEXT_INSN (x))
+    gcc_assert (after != x);
+  gcc_assert (after != to);
+#endif
+
   /* Splice this bunch out of where it is now.  */
   if (PREV_INSN (from))
     NEXT_INSN (PREV_INSN (from)) = NEXT_INSN (to);