diff --git a/src/compiler/code-stub-assembler.h b/src/compiler/code-stub-assembler.h
index 3c4ae05..2ab1376 100644
--- a/src/compiler/code-stub-assembler.h
+++ b/src/compiler/code-stub-assembler.h
@@ -5,11 +5,16 @@
 #ifndef V8_COMPILER_CODE_STUB_ASSEMBLER_H_
 #define V8_COMPILER_CODE_STUB_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 {
@@ -25,48 +30,196 @@
 class Node;
 class Operator;
 class RawMachineAssembler;
+class RawMachineLabel;
 class Schedule;
 
+#define CODE_STUB_ASSEMBLER_BINARY_OP_LIST(V) \
+  V(IntPtrAdd)                                \
+  V(IntPtrSub)                                \
+  V(Int32Add)                                 \
+  V(Int32Sub)                                 \
+  V(Int32Mul)                                 \
+  V(Int32GreaterThanOrEqual)                  \
+  V(WordEqual)                                \
+  V(WordNotEqual)                             \
+  V(WordOr)                                   \
+  V(WordAnd)                                  \
+  V(WordXor)                                  \
+  V(WordShl)                                  \
+  V(WordShr)                                  \
+  V(WordSar)                                  \
+  V(WordRor)                                  \
+  V(Word32Equal)                              \
+  V(Word32NotEqual)                           \
+  V(Word32Or)                                 \
+  V(Word32And)                                \
+  V(Word32Xor)                                \
+  V(Word32Shl)                                \
+  V(Word32Shr)                                \
+  V(Word32Sar)                                \
+  V(Word32Ror)                                \
+  V(Word64Equal)                              \
+  V(Word64NotEqual)                           \
+  V(Word64Or)                                 \
+  V(Word64And)                                \
+  V(Word64Xor)                                \
+  V(Word64Shr)                                \
+  V(Word64Sar)                                \
+  V(Word64Ror)                                \
+  V(UintPtrGreaterThanOrEqual)
+
 class CodeStubAssembler {
  public:
+  // |result_size| specifies the number of results returned by the stub.
+  // TODO(rmcilroy): move result_size to the CallInterfaceDescriptor.
   CodeStubAssembler(Isolate* isolate, Zone* zone,
-                    const CallInterfaceDescriptor& descriptor, Code::Kind kind,
-                    const char* name);
+                    const CallInterfaceDescriptor& descriptor,
+                    Code::Flags flags, const char* name,
+                    size_t result_size = 1);
   virtual ~CodeStubAssembler();
 
   Handle<Code> GenerateCode();
 
+  class Label;
+  class Variable {
+   public:
+    explicit Variable(CodeStubAssembler* assembler, MachineRepresentation rep);
+    void Bind(Node* value);
+    Node* value() const;
+    MachineRepresentation rep() const;
+    bool IsBound() const;
+
+   private:
+    friend class CodeStubAssembler;
+    class Impl;
+    Impl* impl_;
+  };
+
+  // ===========================================================================
+  // Base Assembler
+  // ===========================================================================
+
   // Constants.
   Node* Int32Constant(int value);
   Node* IntPtrConstant(intptr_t value);
   Node* NumberConstant(double value);
   Node* HeapConstant(Handle<HeapObject> object);
   Node* BooleanConstant(bool value);
+  Node* ExternalConstant(ExternalReference address);
 
   Node* Parameter(int value);
   void Return(Node* value);
 
-  // Tag and untag Smi values.
-  Node* SmiTag(Node* value);
-  Node* SmiUntag(Node* value);
+  void Bind(Label* label);
+  void Goto(Label* label);
+  void Branch(Node* condition, Label* true_label, Label* false_label);
 
-  // Basic arithmetic operations.
-  Node* IntPtrAdd(Node* a, Node* b);
-  Node* IntPtrSub(Node* a, Node* b);
+  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);
+
+  // 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);
+
+// Basic arithmetic operations.
+#define DECLARE_CODE_STUB_ASSEMBER_BINARY_OP(name) Node* name(Node* a, Node* b);
+  CODE_STUB_ASSEMBLER_BINARY_OP_LIST(DECLARE_CODE_STUB_ASSEMBER_BINARY_OP)
+#undef DECLARE_CODE_STUB_ASSEMBER_BINARY_OP
+
   Node* WordShl(Node* value, int shift);
 
-  // Load a field from an object on the heap.
-  Node* LoadObjectField(Node* object, int offset);
+  // Conversions
+  Node* ChangeInt32ToInt64(Node* value);
 
-  // Call runtime function.
+  // 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* 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(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(CodeStub& stub, Node** args);
+  Node* TailCall(const CallInterfaceDescriptor& descriptor, Node* target,
+                 Node** args, size_t result_size = 1);
+
+  // ===========================================================================
+  // Macros
+  // ===========================================================================
+
+  // Tag and untag Smi values.
+  Node* SmiTag(Node* value);
+  Node* SmiUntag(Node* value);
+
+  // Load a value from the root array.
+  Node* LoadRoot(Heap::RootListIndex root_index);
+
+  // Check a value for smi-ness
+  Node* WordIsSmi(Node* a);
+
+  // Load an object pointer from a buffer that isn't in the heap.
+  Node* LoadBufferObject(Node* buffer, int offset);
+  // Load a field from an object on the heap.
+  Node* LoadObjectField(Node* object, int offset);
+
+  // Load an array element from a FixedArray.
+  Node* LoadFixedArrayElementSmiIndex(Node* object, Node* smi_index,
+                                      int additional_offset = 0);
+  Node* LoadFixedArrayElementConstantIndex(Node* object, int index);
+
+ protected:
+  // Protected helpers which delegate to RawMachineAssembler.
+  Graph* graph();
+  Isolate* isolate();
+  Zone* zone();
+
+  // Enables subclasses to perform operations before and after a call.
+  virtual void CallPrologue();
+  virtual void CallEpilogue();
 
  private:
   friend class CodeStubAssemblerTester;
@@ -76,19 +229,42 @@
 
   Node* SmiShiftBitsConstant();
 
-  // Private helpers which delegate to RawMachineAssembler.
-  Graph* graph();
-  Isolate* isolate();
-  Zone* zone();
-
   base::SmartPointer<RawMachineAssembler> raw_assembler_;
-  Code::Kind kind_;
+  Code::Flags flags_;
   const char* name_;
   bool code_generated_;
+  ZoneVector<Variable::Impl*> variables_;
 
   DISALLOW_COPY_AND_ASSIGN(CodeStubAssembler);
 };
 
+class CodeStubAssembler::Label {
+ public:
+  explicit Label(CodeStubAssembler* assembler);
+  Label(CodeStubAssembler* assembler, int merged_variable_count,
+        CodeStubAssembler::Variable** merged_variables);
+  Label(CodeStubAssembler* assembler,
+        CodeStubAssembler::Variable* merged_variable);
+  ~Label() {}
+
+ private:
+  friend class CodeStubAssembler;
+
+  void Bind();
+  void MergeVariables();
+
+  bool bound_;
+  size_t merge_count_;
+  CodeStubAssembler* 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