[Interpreter] Collect type feedback for 'new' in the bytecode handler

src/compiler/bytecode-graph-builder.cc

 // Copyright 2015 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.
 
 #include "src/compiler/bytecode-graph-builder.h"
 
 #include "src/compiler/bytecode-branch-analysis.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/operator-properties.h"
 #include "src/interpreter/bytecodes.h"
@@ skipping 1045 matching lines @@
 }
 
 void BytecodeGraphBuilder::VisitNew() {
   FrameStateBeforeAndAfter states(this);
   interpreter::Register callee_reg = bytecode_iterator().GetRegisterOperand(0);
   interpreter::Register first_arg = bytecode_iterator().GetRegisterOperand(1);
   size_t arg_count = bytecode_iterator().GetRegisterCountOperand(2);
 
   Node* new_target = environment()->LookupAccumulator();
   Node* callee = environment()->LookupRegister(callee_reg);
-  // TODO(turbofan): Pass the feedback here.
-  const Operator* call = javascript()->CallConstruct(
-      static_cast<int>(arg_count) + 2, VectorSlotPair());
+
+  // Slot index of 0 is used indicate no feedback slot is available. Assert
+  // the assumption that slot index 0 is never a valid feedback slot.
+  STATIC_ASSERT(TypeFeedbackVector::kReservedIndexCount > 0);
+  VectorSlotPair feedback =
+      CreateVectorSlotPair(bytecode_iterator().GetIndexOperand(3));

[rmcilroy, 2016/07/18 10:13:01]

nit - could you move this to the top where other operands are being read.

[mythria, 2016/07/19 09:50:59]

Done.

+
+  const Operator* call =
+      javascript()->CallConstruct(static_cast<int>(arg_count) + 2, feedback);
   Node* value = ProcessCallNewArguments(call, callee, new_target, first_arg,
                                         arg_count + 2);
   environment()->BindAccumulator(value, &states);
 }
 
 void BytecodeGraphBuilder::BuildThrow() {
   FrameStateBeforeAndAfter states(this);
   Node* value = environment()->LookupAccumulator();
   Node* call = NewNode(javascript()->CallRuntime(Runtime::kThrow), value);
   environment()->BindAccumulator(call, &states);
@@ skipping 705 matching lines @@
     // Phi does not exist yet, introduce one.
     value = NewPhi(inputs, value, control);
     value->ReplaceInput(inputs - 1, other);
   }
   return value;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8