diff --git a/src/interpreter/bytecode-register-allocator.h b/src/interpreter/bytecode-register-allocator.h
index 74ab3a4..696a3b1 100644
--- a/src/interpreter/bytecode-register-allocator.h
+++ b/src/interpreter/bytecode-register-allocator.h
@@ -5,6 +5,7 @@
 #ifndef V8_INTERPRETER_BYTECODE_REGISTER_ALLOCATOR_H_
 #define V8_INTERPRETER_BYTECODE_REGISTER_ALLOCATOR_H_
 
+#include "src/interpreter/bytecodes.h"
 #include "src/zone-containers.h"
 
 namespace v8 {
@@ -14,26 +15,82 @@
 class BytecodeArrayBuilder;
 class Register;
 
+class TemporaryRegisterAllocator final {
+ public:
+  TemporaryRegisterAllocator(Zone* zone, int start_index);
+
+  // Borrow a temporary register.
+  int BorrowTemporaryRegister();
+
+  // Borrow a temporary register from the register range outside of
+  // |start_index| to |end_index|.
+  int BorrowTemporaryRegisterNotInRange(int start_index, int end_index);
+
+  // Return a temporary register when no longer used.
+  void ReturnTemporaryRegister(int reg_index);
+
+  // Ensure a run of consecutive registers is available. Each register in
+  // the range should be borrowed with BorrowConsecutiveTemporaryRegister().
+  // Returns the start index of the run.
+  int PrepareForConsecutiveTemporaryRegisters(size_t count);
+
+  // Borrow a register from a range prepared with
+  // PrepareForConsecutiveTemporaryRegisters().
+  void BorrowConsecutiveTemporaryRegister(int reg_index);
+
+  // Returns true if |reg| is a temporary register and is currently
+  // borrowed.
+  bool RegisterIsLive(Register reg) const;
+
+  // Returns the first register in the range of temporary registers.
+  Register first_temporary_register() const;
+
+  // Returns the last register in the range of temporary registers.
+  Register last_temporary_register() const;
+
+  // Returns the start index of temporary register allocations.
+  int allocation_base() const { return allocation_base_; }
+
+  // Returns the number of temporary register allocations made.
+  int allocation_count() const { return allocation_count_; }
+
+ private:
+  // Allocate a temporary register.
+  int AllocateTemporaryRegister();
+
+  ZoneSet<int> free_temporaries_;
+  int allocation_base_;
+  int allocation_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TemporaryRegisterAllocator);
+};
+
 // A class than allows the instantiator to allocate temporary registers that are
 // cleaned up when scope is closed.
-class BytecodeRegisterAllocator {
+class BytecodeRegisterAllocator final {
  public:
-  explicit BytecodeRegisterAllocator(BytecodeArrayBuilder* builder);
+  explicit BytecodeRegisterAllocator(Zone* zone,
+                                     TemporaryRegisterAllocator* allocator);
   ~BytecodeRegisterAllocator();
   Register NewRegister();
 
+  // Ensure |count| consecutive allocations are available.
   void PrepareForConsecutiveAllocations(size_t count);
+
+  // Get the next consecutive allocation after calling
+  // PrepareForConsecutiveAllocations.
   Register NextConsecutiveRegister();
 
+  // Returns true if |reg| is allocated in this allocator.
   bool RegisterIsAllocatedInThisScope(Register reg) const;
 
+  // Returns true if unused consecutive allocations remain.
   bool HasConsecutiveAllocations() const { return next_consecutive_count_ > 0; }
 
  private:
-  void* operator new(size_t size);
-  void operator delete(void* p);
+  TemporaryRegisterAllocator* base_allocator() const { return base_allocator_; }
 
-  BytecodeArrayBuilder* builder_;
+  TemporaryRegisterAllocator* base_allocator_;
   ZoneVector<int> allocated_;
   int next_consecutive_register_;
   int next_consecutive_count_;