diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/ion/bug889451.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/ion/bug889451.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,18 @@
+/*
+js> (((-1 >>> 1) + 1) * Math.pow(2, 52 - 30) + 1) & 1         
+0
+js> (((-1 >> 1) + 1) * Math.pow(2, 52 - 30) + 1) & 1 
+1
+*/
+ 
+function f(x) {
+  if (x >= 0) {
+    // if it does not fail, try with lower power of 2.
+    return (((x >>> 1) + 1) * 4194304 /* 2 ** (52 - 30) */ + 1) & 1;
+  }
+  return 2;
+}
+ 
+assertEq(f(-1 >>> 1), 1);
+assertEq(f(-1 >>> 0), 0);
+assertEq(f(-1 >>> 0), 0);