diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/auto-regress/bug722260.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/auto-regress/bug722260.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+// Binary: cache/js-dbg-64-8a59519e137e-linux
+// Flags:
+//
+
+var m = new Map;
+var key = -((/\u0024/ ).x);
+var v = {};
+m.set(key,v);