[turbofan] Assign appropriate types to some Date builtins.

src/compiler/js-builtin-reducer.cc

Index: src/compiler/js-builtin-reducer.cc
diff --git a/src/compiler/js-builtin-reducer.cc b/src/compiler/js-builtin-reducer.cc
index 51772fcc802390a4e83feeb2473fe014b878c6f8..16c626792441bcc5ae23b536a1a99a41522cb09b 100644
--- a/src/compiler/js-builtin-reducer.cc
+++ b/src/compiler/js-builtin-reducer.cc
@@ -314,6 +314,67 @@ Reduction JSBuiltinReducer::ReduceArrayPush(Node* node) {
   return NoChange();
 }
 
+namespace {
+
+bool HasInstanceTypeWitness(Node* receiver, Node* effect,
+                            InstanceType instance_type) {
+  for (Node* dominator = effect;;) {
+    if (dominator->opcode() == IrOpcode::kCheckMaps &&
+        dominator->InputAt(0) == receiver) {
+      // Check if all maps have the given {instance_type}.
+      for (int i = 1; i < dominator->op()->ValueInputCount(); ++i) {
+        Node* const map = NodeProperties::GetValueInput(dominator, i);
+        Type* const map_type = NodeProperties::GetType(map);
+        if (!map_type->IsConstant()) return false;
+        Handle<Map> const map_value =
+            Handle<Map>::cast(map_type->AsConstant()->Value());
+        if (map_value->instance_type() != instance_type) return false;
+      }
+      return true;
+    }
+    switch (dominator->opcode()) {
+      case IrOpcode::kStoreField: {
+        FieldAccess const& access = FieldAccessOf(dominator->op());
+        if (access.base_is_tagged == kTaggedBase &&
+            access.offset == HeapObject::kMapOffset) {
+          return false;
+        }
+        break;
+      }
+      case IrOpcode::kStoreElement:
+      case IrOpcode::kStoreTypedElement:
+        break;
+      default: {
+        DCHECK_EQ(1, dominator->op()->EffectOutputCount());
+        if (dominator->op()->EffectInputCount() != 1 ||
+            !dominator->op()->HasProperty(Operator::kNoWrite)) {
+          // Didn't find any appropriate CheckMaps node.
+          return false;
+        }
+        break;
+      }
+    }
+    dominator = NodeProperties::GetEffectInput(dominator);
+  }
+}
+
+}  // namespace
+
+// ES6 section 20.3.4.10 Date.prototype.getTime ( )
+Reduction JSBuiltinReducer::ReduceDateGetTime(Node* node) {
+  Node* receiver = NodeProperties::GetValueInput(node, 1);
+  Node* effect = NodeProperties::GetEffectInput(node);
+  Node* control = NodeProperties::GetControlInput(node);
+  if (HasInstanceTypeWitness(receiver, effect, JS_DATE_TYPE)) {
+    Node* value = effect = graph()->NewNode(
+        simplified()->LoadField(AccessBuilder::ForJSDateValue()), receiver,
+        effect, control);
+    ReplaceWithValue(node, value, effect, control);
+    return Replace(value);
+  }
+  return NoChange();
+}
+
 // ES6 section 20.2.2.1 Math.abs ( x )
 Reduction JSBuiltinReducer::ReduceMathAbs(Node* node) {
   JSCallReduction r(node);
@@ -878,51 +939,6 @@ Reduction JSBuiltinReducer::ReduceStringCharCodeAt(Node* node) {
   return NoChange();
 }
 
-namespace {
-
-bool HasInstanceTypeWitness(Node* receiver, Node* effect,
-                            InstanceType instance_type) {
-  for (Node* dominator = effect;;) {
-    if (dominator->opcode() == IrOpcode::kCheckMaps &&
-        dominator->InputAt(0) == receiver) {
-      // Check if all maps have the given {instance_type}.
-      for (int i = 1; i < dominator->op()->ValueInputCount(); ++i) {
-        Node* const map = NodeProperties::GetValueInput(dominator, i);
-        Type* const map_type = NodeProperties::GetType(map);
-        if (!map_type->IsConstant()) return false;
-        Handle<Map> const map_value =
-            Handle<Map>::cast(map_type->AsConstant()->Value());
-        if (map_value->instance_type() != instance_type) return false;
-      }
-      return true;
-    }
-    switch (dominator->opcode()) {
-      case IrOpcode::kStoreField: {
-        FieldAccess const& access = FieldAccessOf(dominator->op());
-        if (access.base_is_tagged == kTaggedBase &&
-            access.offset == HeapObject::kMapOffset) {
-          return false;
-        }
-        break;
-      }
-      case IrOpcode::kStoreElement:
-        break;
-      default: {
-        DCHECK_EQ(1, dominator->op()->EffectOutputCount());
-        if (dominator->op()->EffectInputCount() != 1 ||
-            !dominator->op()->HasProperty(Operator::kNoWrite)) {
-          // Didn't find any appropriate CheckMaps node.
-          return false;
-        }
-        break;
-      }
-    }
-    dominator = NodeProperties::GetEffectInput(dominator);
-  }
-}
-
-}  // namespace
-
 Reduction JSBuiltinReducer::ReduceArrayBufferViewAccessor(
     Node* node, InstanceType instance_type, FieldAccess const& access) {
   Node* receiver = NodeProperties::GetValueInput(node, 1);
@@ -963,6 +979,8 @@ Reduction JSBuiltinReducer::Reduce(Node* node) {
       return ReduceArrayPop(node);
     case kArrayPush:
       return ReduceArrayPush(node);
+    case kDateGetTime:
+      return ReduceDateGetTime(node);
     case kMathAbs:
       reduction = ReduceMathAbs(node);
       break;