1 files changed, 41 insertions, 0 deletions
diff --git a/js/src/tests/non262/jit/regress-469927.js b/js/src/tests/non262/jit/regress-469927.js
new file mode 100644
index 0000000000..b1a7230946
--- /dev/null
+++ b/js/src/tests/non262/jit/regress-469927.js
@@ -0,0 +1,41 @@
+// |reftest| skip -- bogus perf test (bug 540512)
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+//-----------------------------------------------------------------------------
+var BUGNUMBER = 469927;
+var summary = 'TM: jit should not slow down short loop with let';
+var actual = '';
+var expect = '';
+
+
+//-----------------------------------------------------------------------------
+test();
+//-----------------------------------------------------------------------------
+
+function test()
+{
+  printBugNumber(BUGNUMBER);
+  printStatus (summary);
+ 
+  function letitbe() {
+    var start = new Date();
+    for (let i = 0; i < 500000; ++i) { 
+      for (let j = 0; j < 4; ++j) { } 
+    }
+    var stop = new Date();
+    return stop - start;
+  }
+
+  var timenonjit = letitbe();
+  var timejit = letitbe();
+
+  print('time: nonjit = ' + timenonjit + ', jit = ' + timejit);
+
+  expect = true;
+  actual = timejit < timenonjit;
+
+  reportCompare(expect, actual, summary);
+}