Replace HeapNumber as doublebox with an explicit MutableHeapNumber.

test/mjsunit/migrations.js

Index: test/mjsunit/migrations.js
diff --git a/test/mjsunit/migrations.js b/test/mjsunit/migrations.js
new file mode 100644
index 0000000000000000000000000000000000000000..4faae8e6e28cb34ffcffe77319b2d3e37067d0b3
--- /dev/null
+++ b/test/mjsunit/migrations.js
@@ -0,0 +1,307 @@
+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-ayle license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --track-fields --expose-gc
+
+var global = Function('return this')();
+var verbose = 0;
+
+function test(ctor_desc, use_desc, migr_desc) {
+  var n = 5;
+  var objects = [];
+  var results = [];
+
+  if (verbose) {
+    print();
+    print("===========================================================");
+    print("=== " + ctor_desc.name +
+          " | " + use_desc.name + " |--> " + migr_desc.name);
+    print("===========================================================");
+  }
+
+  // Clean ICs and transitions.
+  %NotifyContextDisposed();
+  gc(); gc(); gc();
+
+
+  // create objects
+  if (verbose) {
+    print("-----------------------------");
+    print("--- construct");
+    print();
+  }
+  for (var i = 0; i < n; i++) {
+    objects[i] = ctor_desc.ctor.apply(ctor_desc, ctor_desc.args(i));
+  }
+
+  try {
+    // use them
+    if (verbose) {
+      print("-----------------------------");
+      print("--- use 1");
+      print();
+    }
+    var use = use_desc.use1;
+    for (var i = 0; i < n; i++) {
+      if (i == 3) %OptimizeFunctionOnNextCall(use);
+      results[i] = use(objects[i], i);
+    }
+
+    // trigger migrations
+    if (verbose) {
+      print("-----------------------------");
+      print("--- trigger migration");
+      print();
+    }
+    var migr = migr_desc.migr;
+    for (var i = 0; i < n; i++) {
+      if (i == 3) %OptimizeFunctionOnNextCall(migr);
+      migr(objects[i], i);
+    }
+
+    // use again
+    if (verbose) {
+      print("-----------------------------");
+      print("--- use 2");
+      print();
+    }
+    var use = use_desc.use2 !== undefined ? use_desc.use2 : use_desc.use1;
+    for (var i = 0; i < n; i++) {
+      if (i == 3) %OptimizeFunctionOnNextCall(use);
+      results[i] = use(objects[i], i);
+      if (verbose >= 2) print(results[i]);
+    }
+
+  } catch (e) {
+    if (verbose) print("--- incompatible use: " + e);
+  }
+  return results;
+}
+
+
+var ctors = [
+  {
+    name: "none-to-double",
+    ctor: function(v) { return {a: v}; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "double",
+    ctor: function(v) { var o = {}; o.a = v; return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "none-to-smi",
+    ctor: function(v) { return {a: v}; },
+    args: function(i) { return [i]; },
+  },
+  {
+    name: "smi",
+    ctor: function(v) { var o = {}; o.a = v; return o; },
+    args: function(i) { return [i]; },
+  },
+  {
+    name: "none-to-object",
+    ctor: function(v) { return {a: v}; },
+    args: function(i) { return ["s"]; },
+  },
+  {
+    name: "object",
+    ctor: function(v) { var o = {}; o.a = v; return o; },
+    args: function(i) { return ["s"]; },
+  },
+  {
+    name: "{a:, b:, c:}",
+    ctor: function(v1, v2, v3) { return {a: v1, b: v2, c: v3}; },
+    args: function(i)    { return [1.5 + i, 1.6, 1.7]; },
+  },
+  {
+    name: "{a..h:}",
+    ctor: function(v) { var o = {}; o.h=o.g=o.f=o.e=o.d=o.c=o.b=o.a=v; return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "1",
+    ctor: function(v) { var o = 1; o.a = v; return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "f()",
+    ctor: function(v) { var o = function() { return v;}; o.a = v; return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "f().bind",
+    ctor: function(v) { var o = function(a,b,c) { return a+b+c; }; o = o.bind(o, v, v+1, v+2.2); return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "dictionary elements",
+    ctor: function(v) { var o = []; o[1] = v; o[200000] = v; return o; },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "json",
+    ctor: function(v) { var json = '{"a":' + v + ',"b":' + v + '}'; return JSON.parse(json); },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "fast accessors",
+    accessor: {
+        get: function() { return this.a_; },
+        set: function(value) {this.a_ = value; },
+        configurable: true,
+    },
+    ctor: function(v) {
+      var o = {a_:v};
+      Object.defineProperty(o, "a", this.accessor);
+      return o;
+    },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "slow accessor",
+    accessor1: { value: this.a_, configurable: true },
+    accessor2: {
+        get: function() { return this.a_; },
+        set: function(value) {this.a_ = value; },
+        configurable: true,
+    },
+    ctor: function(v) {
+      var o = {a_:v};
+      Object.defineProperty(o, "a", this.accessor1);
+      Object.defineProperty(o, "a", this.accessor2);
+      return o;
+    },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "slow",
+    proto: {},
+    ctor: function(v) {
+      var o = {__proto__: this.proto};
+      o.a = v;
+      for (var i = 0; %HasFastProperties(o); i++) o["f"+i] = v;
+      return o;
+    },
+    args: function(i) { return [1.5 + i]; },
+  },
+  {
+    name: "global",
+    ctor: function(v) { return global; },
+    args: function(i) { return [i]; },
+  },
+];
+
+
+
+var uses = [
+  {
+    name: "o.a+1.0",
+    use1: function(o, i) { return o.a + 1.0; },
+    use2: function(o, i) { return o.a + 1.1; },
+  },
+  {
+    name: "o.b+1.0",
+    use1: function(o, i) { return o.b + 1.0; },
+    use2: function(o, i) { return o.b + 1.1; },
+  },
+  {
+    name: "o[1]+1.0",
+    use1: function(o, i) { return o[1] + 1.0; },
+    use2: function(o, i) { return o[1] + 1.1; },
+  },
+  {
+    name: "o[-1]+1.0",
+    use1: function(o, i) { return o[-1] + 1.0; },
+    use2: function(o, i) { return o[-1] + 1.1; },
+  },
+  {
+    name: "()",
+    use1: function(o, i) { return o() + 1.0; },
+    use2: function(o, i) { return o() + 1.1; },
+  },
+];
+
+
+
+var migrations = [
+  {
+    name: "to smi",
+    migr: function(o, i) { if (i == 0) o.a = 1; },
+  },
+  {
+    name: "to double",
+    migr: function(o, i) { if (i == 0) o.a = 1.1; },
+  },
+  {
+    name: "to object",
+    migr: function(o, i) { if (i == 0) o.a = {}; },
+  },
+  {
+    name: "set prototype {}",
+    migr: function(o, i) { o.__proto__ = {}; },
+  },
+  {
+    name: "%FunctionSetPrototype",
+    migr: function(o, i) { %FunctionSetPrototype(o, null); },
+  },
+  {
+    name: "modify prototype",
+    migr: function(o, i) { if (i == 0) o.__proto__.__proto1__ = [,,,5,,,]; },
+  },
+  {
+    name: "freeze prototype",
+    migr: function(o, i) { if (i == 0) Object.freeze(o.__proto__); },
+  },
+  {
+    name: "delete and re-add property",
+    migr: function(o, i) { var v = o.a; delete o.a; o.a = v; },
+  },
+  {
+    name: "modify prototype",
+    migr: function(o, i) { if (i >= 0) o.__proto__ = {}; },
+  },
+  {
+    name: "set property callback",
+    migr: function(o, i) {
+      Object.defineProperty(o, "a", {
+        get: function() { return 1.5 + i; },
+        set: function(value) {},
+        configurable: true,
+      });
+    },
+  },
+  {
+    name: "observe",
+    migr: function(o, i) { Object.observe(o, function(){}); },
+  },
+  {
+    name: "%EnableAccessChecks",
+    migr: function(o, i) { %EnableAccessChecks(o); },
+  },
+  {
+    name: "%DisableAccessChecks",
+    migr: function(o, i) { if (o !== global) %DisableAccessChecks(o); },
+  },
+  {
+    name: "seal",
+    migr: function(o, i) { Object.seal(o); },
+  },
+  { // Must be the last in the sequence, because after the global object freeze
+    // the other modifications does not make sence.
+    name: "freeze",
+    migr: function(o, i) { Object.freeze(o); },
+  },
+];
+
+
+
+migrations.forEach(function(migr) {
+  uses.forEach(function(use) {
+    ctors.forEach(function(ctor) {
+      test(ctor, use, migr);
+    });
+  });
+});