Track field types.

test/mjsunit/field-type-tracking.js

+// Copyright 2014 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 --nostress-opt --track-field-types
+
+(function() {
+  var o = { text: "Hello World!" };
+  function A() {
+    this.a = o;
+  }
+  function readA(x) {
+    return x.a;
+  }
+  var a = new A();
+  assertUnoptimized(readA);
+  readA(a); readA(a); readA(a);
+  %OptimizeFunctionOnNextCall(readA);
+  assertEquals(readA(a), o);
+  assertOptimized(readA);
+
+  var b = new A();
+  b.b = o;
+  assertEquals(readA(b), o);
+  assertUnoptimized(readA);
+  %OptimizeFunctionOnNextCall(readA);
+  assertEquals(readA(a), o);
+  assertOptimized(readA);
+  assertEquals(readA(a), o);
+  assertEquals(readA(b), o);
+  assertOptimized(readA);
+
+  function readAFromB(x) {
+    return x.a;
+  }
+  assertUnoptimized(readAFromB);
+  readAFromB(b); readAFromB(b); readAFromB(b);
+  %OptimizeFunctionOnNextCall(readAFromB);
+  assertEquals(readAFromB(b), o);
+  assertOptimized(readAFromB);
+
+  var c = new A();
+  c.c = o;
+  assertOptimized(readA);
+  assertOptimized(readAFromB);
+  c.a = [1];
+  assertUnoptimized(readA);
+  assertUnoptimized(readAFromB);
+  assertEquals(readA(a), o);
+  assertEquals(readA(b), o);
+  assertEquals(readA(c), [1]);
+  assertEquals(readAFromB(b), o);
+
+  %OptimizeFunctionOnNextCall(readA);
+  assertEquals(readA(a), o);
+  %OptimizeFunctionOnNextCall(readAFromB);
+  assertEquals(readAFromB(b), o);
+  assertOptimized(readA);
+  a.a = [1];
+  assertEquals(readA(a), [1]);
+  assertEquals(readA(b), o);
+  assertEquals(readA(c), [1]);
+  assertOptimized(readA);
+  b.a = [1];
+  assertEquals(readA(a), [1]);
+  assertEquals(readA(b), [1]);
+  assertEquals(readA(c), [1]);
+  assertOptimized(readA);
+  assertOptimized(readAFromB);
+})();
+
+(function() {
+  function A() { this.x = 0; }
+  A.prototype = {y: 20};
+  function B(o) { return o.a.y; }
+  function C() { this.a = new A(); }
+
+  B(new C());
+  B(new C());
+  %OptimizeFunctionOnNextCall(B);
+  var c = new C();
+  assertEquals(20, B(c));
+  assertOptimized(B);
+  c.a.y = 10;
+  assertEquals(10, B(c));
+  assertUnoptimized(B);
+
+  var c = new C();
+  %OptimizeFunctionOnNextCall(B);
+  assertEquals(20, B(c));
+  assertOptimized(B);
+  c.a.y = 30;
+  assertEquals(30, B(c));
+  assertOptimized(B);
+})();
+
+(function() {
+  var x = new Object();
+  x.a = 1 + "Long string that results in a cons string";
+  x = JSON.parse('{"a":"Short"}');
+})();
+
+(function() {
+  var x = {y: {z: 1}};
+  x.y.z = 1.1;
+})();