1 files changed, 34 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/ion/idempotentCache.js b/js/src/jit-test/tests/ion/idempotentCache.js
new file mode 100644
index 0000000000..6a54bb72e5
--- /dev/null
+++ b/js/src/jit-test/tests/ion/idempotentCache.js
@@ -0,0 +1,34 @@
+// Test that we don't attach ICs to idempotent caches that are incompatible
+// with the cache result type.
+
+var missingObjs = [{a:1},Object.create({a:2}),{}];
+function testMissing(limit)
+{
+    var res = 0;
+    for (var i = 0; i < 1000; i++) {
+	for (var j = 0; j < missingObjs.length; j++) {
+	    var obj = missingObjs[j];
+	    if (j < limit)
+		res += obj.a;
+	}
+    }
+    return res;
+}
+assertEq(testMissing(2), 3000);
+assertEq(testMissing(3), NaN);
+
+var lengthObjs = [{length:{a:1}},Object.create({length:{a:2}}),[0,1]];
+function testArrayLength(limit)
+{
+    var res = 0;
+    for (var i = 0; i < 1000; i++) {
+	for (var j = 0; j < lengthObjs.length; j++) {
+	    var obj = lengthObjs[j];
+	    if (j < limit)
+		res += obj.length.a;
+	}
+    }
+    return res;
+}
+assertEq(testArrayLength(2), 3000);
+assertEq(testArrayLength(3), NaN);