Adding a type vector to replace type cells.

src/feedback_slots.h

Index: src/feedback_slots.h
diff --git a/src/feedback_slots.h b/src/feedback_slots.h
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+// Copyright 2014 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_FEEDBACK_SLOTS_H_
+#define V8_FEEDBACK_SLOTS_H_
+
+#include "v8.h"
+
+#include "isolate.h"
+
+namespace v8 {
+namespace internal {
+
+enum ComputablePhase {
+  DURING_PARSE,
+  AFTER_SCOPING
+};
+
+
+class FeedbackSlotInterface {
+ public:
+  static const int kInvalidFeedbackSlot = -1;
+
+  virtual ~FeedbackSlotInterface() {}
+
+  // When can we ask how many feedback slots are necessary?
+  virtual ComputablePhase GetComputablePhase() = 0;
+  virtual int GetFeedbackSlotCount(Isolate* isolate) = 0;

[Benedikt Meurer, 2014/02/07 09:29:25]

Nit: Rename to ComputeFeedbackSlotCount().

[mvstanton, 2014/02/07 10:39:22]

excellent idea, thx.

+  virtual void SetFirstFeedbackSlot(int slot) = 0;
+};
+
+
+class DeferredFeedbackSlotProcessor {
+ public:
+  DeferredFeedbackSlotProcessor()
+    : slot_nodes_(NULL),
+      slot_count_(0) { }
+
+  void add_slot_node(Zone* zone, FeedbackSlotInterface* slot) {
+    if (slot->GetComputablePhase() == DURING_PARSE) {
+      // No need to add to the list
+      int count = slot->GetFeedbackSlotCount(zone->isolate());
+      slot->SetFirstFeedbackSlot(slot_count_);
+      slot_count_ += count;
+    } else {
+      if (slot_nodes_ == NULL) {
+        slot_nodes_ = new(zone) ZoneList<FeedbackSlotInterface*>(10, zone);
+      }
+      slot_nodes_->Add(slot, zone);
+    }
+  }
+
+  void ProcessFeedbackSlots(Isolate* isolate) {
+    // Scope analysis must have been done.
+    if (slot_nodes_ == NULL) {
+      return;
+    }
+
+    int current_slot = slot_count_;
+    for (int i = 0; i < slot_nodes_->length(); i++) {
+      FeedbackSlotInterface* slot_interface = slot_nodes_->at(i);
+      int count = slot_interface->GetFeedbackSlotCount(isolate);
+      if (count > 0) {
+        slot_interface->SetFirstFeedbackSlot(current_slot);
+        current_slot += count;
+      }
+    }
+
+    slot_count_ = current_slot;
+    slot_nodes_->Clear();
+  }
+
+  int slot_count() {
+    ASSERT(slot_count_ >= 0);
+    return slot_count_;
+  }
+
+ private:
+  ZoneList<FeedbackSlotInterface*>* slot_nodes_;
+  int slot_count_;
+};
+
+
+} }  // namespace v8::internal
+
+#endif  // V8_FEEDBACK_SLOTS_H_