1 files changed, 127 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/regress/regress-997485.js b/deps/v8/test/mjsunit/regress/regress-997485.js
new file mode 100644
index 0000000000..bcc1664222
--- /dev/null
+++ b/deps/v8/test/mjsunit/regress/regress-997485.js
@@ -0,0 +1,127 @@
+// Copyright 2019 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
+
+(function doubleToTaggedWithTaggedValueStoresCorrectly() {
+
+  function setX_Double(o) { o.x = 4.2; }
+
+  function foo() {
+    // o.x starts off as Double
+    const o = { x: 0.1 };
+
+    // Write to it a few times with setX_Double, to make sure setX_Double has
+    // Double feedback.
+    setX_Double(o);
+    setX_Double(o);
+
+    // Transition o.x to Tagged.
+    o.x = {};
+
+    // setX_Double will still have Double feedback, so make sure it works with
+    // the new Tagged representation o.x.
+    setX_Double(o);
+
+    assertEquals(o.x, 4.2);
+  }
+
+  %EnsureFeedbackVectorForFunction(setX_Double);
+  foo();
+
+})();
+
+(function doubleToTaggedWithDoubleValueDoesNotMutate() {
+
+  function setX_Double(o) { o.x = 4.2; }
+
+  function foo() {
+    // o.x starts off as Double
+    const o = { x: 0.1 };
+
+    // Write to it a few times with setX_Double, to make sure setX_Double has
+    // Double feedback.
+    setX_Double(o);
+    setX_Double(o);
+
+    // Transition o.x to Tagged.
+    o.x = {};
+
+    // Write the HeapNumber val to o.x.
+    const val = 1.25;
+    o.x = val;
+
+    // setX_Double will still have Double feedback, which expects to be able to
+    // mutate o.x's HeapNumber, so make sure it does not mutate val.
+    setX_Double(o);
+
+    assertEquals(o.x, 4.2);
+    assertNotEquals(val, 4.2);
+  }
+
+  %EnsureFeedbackVectorForFunction(setX_Double);
+  foo();
+
+})();
+
+(function doubleToTaggedWithTaggedValueStoresSmiCorrectly() {
+
+  function setX_Smi(o) { o.x = 42; }
+
+  function foo() {
+    // o.x starts off as Double
+    const o = { x: 0.1 };
+
+    // Write to it a few times with setX_Smi, to make sure setX_Smi has
+    // Double feedback.
+    setX_Smi(o);
+    setX_Smi(o);
+
+    // Transition o.x to Tagged.
+    o.x = {};
+
+    // setX_Smi will still have Double feedback, so make sure it works with
+    // the new Tagged representation o.x.
+    setX_Smi(o);
+
+    assertEquals(o.x, 42);
+  }
+
+  %EnsureFeedbackVectorForFunction(setX_Smi);
+  foo();
+
+})();
+
+(function doubleToTaggedWithSmiValueDoesNotMutate() {
+
+  function setX_Smi(o) { o.x = 42; }
+
+  function foo() {
+    // o.x starts off as Double
+    const o = { x: 0.1 };
+
+    // Write to it a few times with setX_Smi, to make sure setX_Smi has
+    // Double feedback.
+    setX_Smi(o);
+    setX_Smi(o);
+
+    // Transition o.x to Tagged.
+    o.x = {};
+
+    // Write the HeapNumber val to o.x.
+    const val = 1.25;
+    o.x = val;
+
+    // setX_Smi will still have Double feedback, which expects to be able to
+    // mutate o.x's HeapNumber, so make sure it does not mutate val.
+    setX_Smi(o);
+
+    assertEquals(o.x, 42);
+    assertNotEquals(val, 42);
+  }
+
+  %EnsureFeedbackVectorForFunction(setX_Smi);
+  foo();
+
+})();