diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug620637.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug620637.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+// |jit-test| error:Error
+
+// Binary: cache/js-dbg-64-aeeb631c6d43-linux
+// Flags:
+//
+options('tracejit');
+var actual = ''
+function f() {
+    for (var a = 0; a < 3; ++a) {
+        (function () {
+            for (var b = 0; b < 2; ++b) {
+                (function () {
+                    for (a = 0, b = 0; b < 15; b++, actual = actual + "7") {
+                    }
+                })();
+            }
+        })();
+    }
+}
+f();