1 files changed, 57 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/warp/arguments-object-load-length.js b/js/src/jit-test/tests/warp/arguments-object-load-length.js
new file mode 100644
index 0000000000..935c406ac0
--- /dev/null
+++ b/js/src/jit-test/tests/warp/arguments-object-load-length.js
@@ -0,0 +1,57 @@
+// Test transpiling of LoadArgumentsObjectLengthResult and cover all possible bailout conditions.
+
+function blackhole() {
+  // Direct eval prevents any compile-time optimisations.
+  eval("");
+}
+
+function testLengthAccess() {
+  blackhole(arguments); // Create an arguments object.
+
+  for (var i = 0; i < 50; ++i) {
+    assertEq(arguments.length, 1);
+  }
+}
+for (var i = 0; i < 20; ++i) testLengthAccess(1);
+
+function markLengthOveriddenIf(args, cond, value) {
+  with ({}) ; // Don't Warp compile to avoid cold code bailouts.
+  if (cond) {
+    args.length = value;
+  }
+}
+
+function testBailoutLengthReified() {
+  blackhole(arguments); // Create an arguments object.
+
+  for (var i = 0; i < 50; ++i) {
+    markLengthOveriddenIf(arguments, i === 25, 0);
+
+    var expected = 0 + (i < 25);
+    assertEq(arguments.length, expected);
+  }
+}
+for (var i = 0; i < 20; ++i) testBailoutLengthReified(1);
+
+
+function deleteLengthIf(args, cond) {
+  with ({}) ; // Don't Warp compile to avoid cold code bailouts.
+  if (cond) {
+    delete args.length;
+  }
+}
+
+function testBailoutLengthDeleted() {
+  blackhole(arguments); // Create an arguments object.
+
+  // Load expected values from an array to avoid possible cold code bailouts.
+  var values = [1, undefined];
+
+  for (var i = 0; i < 50; ++i) {
+    deleteLengthIf(arguments, i === 25);
+
+    var expected = values[0 + (i >= 25)];
+    assertEq(arguments.length, expected);
+  }
+}
+for (var i = 0; i < 20; ++i) testBailoutLengthDeleted(1);