diff --git a/src/compiler/code-assembler.h b/src/compiler/code-assembler.h
new file mode 100644
index 0000000..39af56d
--- /dev/null
+++ b/src/compiler/code-assembler.h
@@ -0,0 +1,408 @@
+// 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.
+
+#ifndef V8_COMPILER_CODE_ASSEMBLER_H_
+#define V8_COMPILER_CODE_ASSEMBLER_H_
+
+#include <map>
+
+// Clients of this interface shouldn't depend on lots of compiler internals.
+// Do not include anything from src/compiler here!
+#include "src/allocation.h"
+#include "src/builtins.h"
+#include "src/heap/heap.h"
+#include "src/machine-type.h"
+#include "src/runtime/runtime.h"
+#include "src/zone-containers.h"
+
+namespace v8 {
+namespace internal {
+
+class Callable;
+class CallInterfaceDescriptor;
+class Isolate;
+class Factory;
+class Zone;
+
+namespace compiler {
+
+class CallDescriptor;
+class Graph;
+class Node;
+class Operator;
+class RawMachineAssembler;
+class RawMachineLabel;
+class Schedule;
+
+#define CODE_ASSEMBLER_COMPARE_BINARY_OP_LIST(V) \
+  V(Float32Equal)                                \
+  V(Float32LessThan)                             \
+  V(Float32LessThanOrEqual)                      \
+  V(Float32GreaterThan)                          \
+  V(Float32GreaterThanOrEqual)                   \
+  V(Float64Equal)                                \
+  V(Float64LessThan)                             \
+  V(Float64LessThanOrEqual)                      \
+  V(Float64GreaterThan)                          \
+  V(Float64GreaterThanOrEqual)                   \
+  V(Int32GreaterThan)                            \
+  V(Int32GreaterThanOrEqual)                     \
+  V(Int32LessThan)                               \
+  V(Int32LessThanOrEqual)                        \
+  V(IntPtrLessThan)                              \
+  V(IntPtrLessThanOrEqual)                       \
+  V(IntPtrGreaterThan)                           \
+  V(IntPtrGreaterThanOrEqual)                    \
+  V(IntPtrEqual)                                 \
+  V(Uint32LessThan)                              \
+  V(UintPtrLessThan)                             \
+  V(UintPtrGreaterThanOrEqual)                   \
+  V(WordEqual)                                   \
+  V(WordNotEqual)                                \
+  V(Word32Equal)                                 \
+  V(Word32NotEqual)                              \
+  V(Word64Equal)                                 \
+  V(Word64NotEqual)
+
+#define CODE_ASSEMBLER_BINARY_OP_LIST(V)   \
+  CODE_ASSEMBLER_COMPARE_BINARY_OP_LIST(V) \
+  V(Float64Add)                            \
+  V(Float64Sub)                            \
+  V(Float64Mul)                            \
+  V(Float64Div)                            \
+  V(Float64Mod)                            \
+  V(Float64InsertLowWord32)                \
+  V(Float64InsertHighWord32)               \
+  V(IntPtrAdd)                             \
+  V(IntPtrAddWithOverflow)                 \
+  V(IntPtrSub)                             \
+  V(IntPtrSubWithOverflow)                 \
+  V(IntPtrMul)                             \
+  V(Int32Add)                              \
+  V(Int32AddWithOverflow)                  \
+  V(Int32Sub)                              \
+  V(Int32Mul)                              \
+  V(Int32Div)                              \
+  V(WordOr)                                \
+  V(WordAnd)                               \
+  V(WordXor)                               \
+  V(WordShl)                               \
+  V(WordShr)                               \
+  V(WordSar)                               \
+  V(WordRor)                               \
+  V(Word32Or)                              \
+  V(Word32And)                             \
+  V(Word32Xor)                             \
+  V(Word32Shl)                             \
+  V(Word32Shr)                             \
+  V(Word32Sar)                             \
+  V(Word32Ror)                             \
+  V(Word64Or)                              \
+  V(Word64And)                             \
+  V(Word64Xor)                             \
+  V(Word64Shr)                             \
+  V(Word64Sar)                             \
+  V(Word64Ror)
+
+#define CODE_ASSEMBLER_UNARY_OP_LIST(V) \
+  V(Float64Neg)                         \
+  V(Float64Sqrt)                        \
+  V(Float64ExtractLowWord32)            \
+  V(Float64ExtractHighWord32)           \
+  V(BitcastWordToTagged)                \
+  V(TruncateFloat64ToWord32)            \
+  V(TruncateInt64ToInt32)               \
+  V(ChangeFloat64ToUint32)              \
+  V(ChangeInt32ToFloat64)               \
+  V(ChangeInt32ToInt64)                 \
+  V(ChangeUint32ToFloat64)              \
+  V(ChangeUint32ToUint64)               \
+  V(RoundFloat64ToInt32)                \
+  V(Float64RoundDown)                   \
+  V(Float64RoundUp)                     \
+  V(Float64RoundTruncate)               \
+  V(Word32Clz)
+
+// A "public" interface used by components outside of compiler directory to
+// create code objects with TurboFan's backend. This class is mostly a thin shim
+// around the RawMachineAssembler, and its primary job is to ensure that the
+// innards of the RawMachineAssembler and other compiler implementation details
+// don't leak outside of the the compiler directory..
+//
+// V8 components that need to generate low-level code using this interface
+// should include this header--and this header only--from the compiler directory
+// (this is actually enforced). Since all interesting data structures are
+// forward declared, it's not possible for clients to peek inside the compiler
+// internals.
+//
+// In addition to providing isolation between TurboFan and code generation
+// clients, CodeAssembler also provides an abstraction for creating variables
+// and enhanced Label functionality to merge variable values along paths where
+// they have differing values, including loops.
+class CodeAssembler {
+ public:
+  // Create with CallStub linkage.
+  // |result_size| specifies the number of results returned by the stub.
+  // TODO(rmcilroy): move result_size to the CallInterfaceDescriptor.
+  CodeAssembler(Isolate* isolate, Zone* zone,
+                const CallInterfaceDescriptor& descriptor, Code::Flags flags,
+                const char* name, size_t result_size = 1);
+
+  // Create with JSCall linkage.
+  CodeAssembler(Isolate* isolate, Zone* zone, int parameter_count,
+                Code::Flags flags, const char* name);
+
+  virtual ~CodeAssembler();
+
+  Handle<Code> GenerateCode();
+
+  bool Is64() const;
+  bool IsFloat64RoundUpSupported() const;
+  bool IsFloat64RoundDownSupported() const;
+  bool IsFloat64RoundTruncateSupported() const;
+
+  class Label;
+  class Variable {
+   public:
+    explicit Variable(CodeAssembler* assembler, MachineRepresentation rep);
+    void Bind(Node* value);
+    Node* value() const;
+    MachineRepresentation rep() const;
+    bool IsBound() const;
+
+   private:
+    friend class CodeAssembler;
+    class Impl;
+    Impl* impl_;
+  };
+
+  enum AllocationFlag : uint8_t {
+    kNone = 0,
+    kDoubleAlignment = 1,
+    kPretenured = 1 << 1
+  };
+
+  typedef base::Flags<AllocationFlag> AllocationFlags;
+
+  // ===========================================================================
+  // Base Assembler
+  // ===========================================================================
+
+  // Constants.
+  Node* Int32Constant(int32_t value);
+  Node* Int64Constant(int64_t value);
+  Node* IntPtrConstant(intptr_t value);
+  Node* NumberConstant(double value);
+  Node* SmiConstant(Smi* value);
+  Node* HeapConstant(Handle<HeapObject> object);
+  Node* BooleanConstant(bool value);
+  Node* ExternalConstant(ExternalReference address);
+  Node* Float64Constant(double value);
+  Node* NaNConstant();
+
+  bool ToInt32Constant(Node* node, int32_t& out_value);
+  bool ToInt64Constant(Node* node, int64_t& out_value);
+  bool ToIntPtrConstant(Node* node, intptr_t& out_value);
+
+  Node* Parameter(int value);
+  void Return(Node* value);
+
+  void Bind(Label* label);
+  void Goto(Label* label);
+  void GotoIf(Node* condition, Label* true_label);
+  void GotoUnless(Node* condition, Label* false_label);
+  void Branch(Node* condition, Label* true_label, Label* false_label);
+
+  void Switch(Node* index, Label* default_label, int32_t* case_values,
+              Label** case_labels, size_t case_count);
+
+  // Access to the frame pointer
+  Node* LoadFramePointer();
+  Node* LoadParentFramePointer();
+
+  // Access to the stack pointer
+  Node* LoadStackPointer();
+
+  // Load raw memory location.
+  Node* Load(MachineType rep, Node* base);
+  Node* Load(MachineType rep, Node* base, Node* index);
+  Node* AtomicLoad(MachineType rep, Node* base, Node* index);
+
+  // Load a value from the root array.
+  Node* LoadRoot(Heap::RootListIndex root_index);
+
+  // Store value to raw memory location.
+  Node* Store(MachineRepresentation rep, Node* base, Node* value);
+  Node* Store(MachineRepresentation rep, Node* base, Node* index, Node* value);
+  Node* StoreNoWriteBarrier(MachineRepresentation rep, Node* base, Node* value);
+  Node* StoreNoWriteBarrier(MachineRepresentation rep, Node* base, Node* index,
+                            Node* value);
+  Node* AtomicStore(MachineRepresentation rep, Node* base, Node* index,
+                    Node* value);
+
+  // Store a value to the root array.
+  Node* StoreRoot(Heap::RootListIndex root_index, Node* value);
+
+// Basic arithmetic operations.
+#define DECLARE_CODE_ASSEMBLER_BINARY_OP(name) Node* name(Node* a, Node* b);
+  CODE_ASSEMBLER_BINARY_OP_LIST(DECLARE_CODE_ASSEMBLER_BINARY_OP)
+#undef DECLARE_CODE_ASSEMBLER_BINARY_OP
+
+  Node* WordShl(Node* value, int shift);
+  Node* WordShr(Node* value, int shift);
+
+// Unary
+#define DECLARE_CODE_ASSEMBLER_UNARY_OP(name) Node* name(Node* a);
+  CODE_ASSEMBLER_UNARY_OP_LIST(DECLARE_CODE_ASSEMBLER_UNARY_OP)
+#undef DECLARE_CODE_ASSEMBLER_UNARY_OP
+
+  // No-op on 32-bit, otherwise zero extend.
+  Node* ChangeUint32ToWord(Node* value);
+  // No-op on 32-bit, otherwise sign extend.
+  Node* ChangeInt32ToIntPtr(Node* value);
+
+  // Projections
+  Node* Projection(int index, Node* value);
+
+  // Calls
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1,
+                    Node* arg2);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1,
+                    Node* arg2, Node* arg3);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1,
+                    Node* arg2, Node* arg3, Node* arg4);
+  Node* CallRuntime(Runtime::FunctionId function_id, Node* context, Node* arg1,
+                    Node* arg2, Node* arg3, Node* arg4, Node* arg5);
+
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context);
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1);
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1, Node* arg2);
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1, Node* arg2, Node* arg3);
+  Node* TailCallRuntime(Runtime::FunctionId function_id, Node* context,
+                        Node* arg1, Node* arg2, Node* arg3, Node* arg4);
+
+  Node* CallStub(Callable const& callable, Node* context, Node* arg1,
+                 size_t result_size = 1);
+  Node* CallStub(Callable const& callable, Node* context, Node* arg1,
+                 Node* arg2, size_t result_size = 1);
+  Node* CallStub(Callable const& callable, Node* context, Node* arg1,
+                 Node* arg2, Node* arg3, size_t result_size = 1);
+
+  Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node* context, Node* arg1, size_t result_size = 1);
+  Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node* context, Node* arg1, Node* arg2, size_t result_size = 1);
+  Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node* context, Node* arg1, Node* arg2, Node* arg3,
+                 size_t result_size = 1);
+  Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node* context, Node* arg1, Node* arg2, Node* arg3, Node* arg4,
+                 size_t result_size = 1);
+  Node* CallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node* context, Node* arg1, Node* arg2, Node* arg3, Node* arg4,
+                 Node* arg5, size_t result_size = 1);
+
+  Node* TailCallStub(Callable const& callable, Node* context, Node* arg1,
+                     Node* arg2, size_t result_size = 1);
+  Node* TailCallStub(Callable const& callable, Node* context, Node* arg1,
+                     Node* arg2, Node* arg3, size_t result_size = 1);
+  Node* TailCallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                     Node* context, Node* arg1, Node* arg2,
+                     size_t result_size = 1);
+  Node* TailCallStub(const CallInterfaceDescriptor& descriptor, Node* target,
+                     Node* context, Node* arg1, Node* arg2, Node* arg3,
+                     size_t result_size = 1);
+
+  Node* TailCallBytecodeDispatch(const CallInterfaceDescriptor& descriptor,
+                                 Node* code_target_address, Node** args);
+
+  // Branching helpers.
+  void BranchIf(Node* condition, Label* if_true, Label* if_false);
+
+#define BRANCH_HELPER(name)                                                \
+  void BranchIf##name(Node* a, Node* b, Label* if_true, Label* if_false) { \
+    BranchIf(name(a, b), if_true, if_false);                               \
+  }
+  CODE_ASSEMBLER_COMPARE_BINARY_OP_LIST(BRANCH_HELPER)
+#undef BRANCH_HELPER
+
+  // Helpers which delegate to RawMachineAssembler.
+  Factory* factory() const;
+  Isolate* isolate() const;
+  Zone* zone() const;
+
+ protected:
+  // Protected helpers which delegate to RawMachineAssembler.
+  Graph* graph() const;
+
+  Node* SmiShiftBitsConstant();
+
+  // Enables subclasses to perform operations before and after a call.
+  virtual void CallPrologue();
+  virtual void CallEpilogue();
+
+ private:
+  friend class CodeAssemblerTester;
+
+  CodeAssembler(Isolate* isolate, Zone* zone, CallDescriptor* call_descriptor,
+                Code::Flags flags, const char* name);
+
+  Node* CallN(CallDescriptor* descriptor, Node* code_target, Node** args);
+  Node* TailCallN(CallDescriptor* descriptor, Node* code_target, Node** args);
+
+  base::SmartPointer<RawMachineAssembler> raw_assembler_;
+  Code::Flags flags_;
+  const char* name_;
+  bool code_generated_;
+  ZoneVector<Variable::Impl*> variables_;
+
+  DISALLOW_COPY_AND_ASSIGN(CodeAssembler);
+};
+
+DEFINE_OPERATORS_FOR_FLAGS(CodeAssembler::AllocationFlags);
+
+class CodeAssembler::Label {
+ public:
+  enum Type { kDeferred, kNonDeferred };
+
+  explicit Label(
+      CodeAssembler* assembler,
+      CodeAssembler::Label::Type type = CodeAssembler::Label::kNonDeferred)
+      : CodeAssembler::Label(assembler, 0, nullptr, type) {}
+  Label(CodeAssembler* assembler, CodeAssembler::Variable* merged_variable,
+        CodeAssembler::Label::Type type = CodeAssembler::Label::kNonDeferred)
+      : CodeAssembler::Label(assembler, 1, &merged_variable, type) {}
+  Label(CodeAssembler* assembler, int merged_variable_count,
+        CodeAssembler::Variable** merged_variables,
+        CodeAssembler::Label::Type type = CodeAssembler::Label::kNonDeferred);
+  ~Label() {}
+
+ private:
+  friend class CodeAssembler;
+
+  void Bind();
+  void MergeVariables();
+
+  bool bound_;
+  size_t merge_count_;
+  CodeAssembler* assembler_;
+  RawMachineLabel* label_;
+  // Map of variables that need to be merged to their phi nodes (or placeholders
+  // for those phis).
+  std::map<Variable::Impl*, Node*> variable_phis_;
+  // Map of variables to the list of value nodes that have been added from each
+  // merge path in their order of merging.
+  std::map<Variable::Impl*, std::vector<Node*>> variable_merges_;
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_CODE_ASSEMBLER_H_