--- a/js/src/trace-test.js
+++ b/js/src/trace-test.js
@@ -279,11 +279,22 @@ function testincops(n) {
   while (a[i]-- > 0);
   for (a[i] = 0; a[i] < n; ++a[i]);
   while (--a[i] >= 0);
 
   return [++o.p, ++a[i]].toString();
 }
 test("testincops", testincops(100), "0,0");
 
+function trees() {
+  var i = 0, o = [0,0,0];  
+  for (i = 0; i < 100; ++i) {
+    if ((i & 1) == 0) o[0]++;
+    else if ((i & 2) == 0) o[1]++;
+    else o[2]++;
+  }
+  return o;
+}
+test("trees", trees(), "50,25,25");
+
 /* Keep these at the end so that we can see the summary after the trace-debug spew. */
 print("pass:", passes.length ? passes.join(",") : "<none>");
 print("FAIL:", fails.length ? fails.join(",") : "<none>");