1 files changed, 22 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/compiler/number-round.js b/deps/v8/test/mjsunit/compiler/number-round.js
new file mode 100644
index 0000000000..9aec7f7a12
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/number-round.js
@@ -0,0 +1,22 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --opt
+
+// Test that NumberRound propagates kIdentifyZeros truncations.
+(function() {
+  function foo(x) {
+    return Math.abs(Math.round(x * -2));
+  }
+
+  assertEquals(2, foo(1));
+  assertEquals(4, foo(2));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals(2, foo(1));
+  assertEquals(4, foo(2));
+  assertOptimized(foo);
+  // Now `foo` should stay optimized even if `x * -2` would produce `-0`.
+  assertEquals(0, foo(0));
+  assertOptimized(foo);
+})();