diff --git a/Eigen/src/IterativeLinearSolvers/IterativeSolverBase.h b/Eigen/src/IterativeLinearSolvers/IterativeSolverBase.h
new file mode 100644
index 0000000..2036922
--- /dev/null
+++ b/Eigen/src/IterativeLinearSolvers/IterativeSolverBase.h
@@ -0,0 +1,254 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2011 Gael Guennebaud <gael.guennebaud@inria.fr>
+//
+// This Source Code Form is subject to the terms of the Mozilla
+// Public License v. 2.0. If a copy of the MPL was not distributed
+// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef EIGEN_ITERATIVE_SOLVER_BASE_H
+#define EIGEN_ITERATIVE_SOLVER_BASE_H
+
+namespace Eigen { 
+
+/** \ingroup IterativeLinearSolvers_Module
+  * \brief Base class for linear iterative solvers
+  *
+  * \sa class SimplicialCholesky, DiagonalPreconditioner, IdentityPreconditioner
+  */
+template< typename Derived>
+class IterativeSolverBase : internal::noncopyable
+{
+public:
+  typedef typename internal::traits<Derived>::MatrixType MatrixType;
+  typedef typename internal::traits<Derived>::Preconditioner Preconditioner;
+  typedef typename MatrixType::Scalar Scalar;
+  typedef typename MatrixType::Index Index;
+  typedef typename MatrixType::RealScalar RealScalar;
+
+public:
+
+  Derived& derived() { return *static_cast<Derived*>(this); }
+  const Derived& derived() const { return *static_cast<const Derived*>(this); }
+
+  /** Default constructor. */
+  IterativeSolverBase()
+    : mp_matrix(0)
+  {
+    init();
+  }
+
+  /** Initialize the solver with matrix \a A for further \c Ax=b solving.
+    * 
+    * This constructor is a shortcut for the default constructor followed
+    * by a call to compute().
+    * 
+    * \warning this class stores a reference to the matrix A as well as some
+    * precomputed values that depend on it. Therefore, if \a A is changed
+    * this class becomes invalid. Call compute() to update it with the new
+    * matrix A, or modify a copy of A.
+    */
+  IterativeSolverBase(const MatrixType& A)
+  {
+    init();
+    compute(A);
+  }
+
+  ~IterativeSolverBase() {}
+  
+  /** Initializes the iterative solver for the sparcity pattern of the matrix \a A for further solving \c Ax=b problems.
+    *
+    * Currently, this function mostly call analyzePattern on the preconditioner. In the future
+    * we might, for instance, implement column reodering for faster matrix vector products.
+    */
+  Derived& analyzePattern(const MatrixType& A)
+  {
+    m_preconditioner.analyzePattern(A);
+    m_isInitialized = true;
+    m_analysisIsOk = true;
+    m_info = Success;
+    return derived();
+  }
+  
+  /** Initializes the iterative solver with the numerical values of the matrix \a A for further solving \c Ax=b problems.
+    *
+    * Currently, this function mostly call factorize on the preconditioner.
+    *
+    * \warning this class stores a reference to the matrix A as well as some
+    * precomputed values that depend on it. Therefore, if \a A is changed
+    * this class becomes invalid. Call compute() to update it with the new
+    * matrix A, or modify a copy of A.
+    */
+  Derived& factorize(const MatrixType& A)
+  {
+    eigen_assert(m_analysisIsOk && "You must first call analyzePattern()"); 
+    mp_matrix = &A;
+    m_preconditioner.factorize(A);
+    m_factorizationIsOk = true;
+    m_info = Success;
+    return derived();
+  }
+
+  /** Initializes the iterative solver with the matrix \a A for further solving \c Ax=b problems.
+    *
+    * Currently, this function mostly initialized/compute the preconditioner. In the future
+    * we might, for instance, implement column reodering for faster matrix vector products.
+    *
+    * \warning this class stores a reference to the matrix A as well as some
+    * precomputed values that depend on it. Therefore, if \a A is changed
+    * this class becomes invalid. Call compute() to update it with the new
+    * matrix A, or modify a copy of A.
+    */
+  Derived& compute(const MatrixType& A)
+  {
+    mp_matrix = &A;
+    m_preconditioner.compute(A);
+    m_isInitialized = true;
+    m_analysisIsOk = true;
+    m_factorizationIsOk = true;
+    m_info = Success;
+    return derived();
+  }
+
+  /** \internal */
+  Index rows() const { return mp_matrix ? mp_matrix->rows() : 0; }
+  /** \internal */
+  Index cols() const { return mp_matrix ? mp_matrix->cols() : 0; }
+
+  /** \returns the tolerance threshold used by the stopping criteria */
+  RealScalar tolerance() const { return m_tolerance; }
+  
+  /** Sets the tolerance threshold used by the stopping criteria */
+  Derived& setTolerance(const RealScalar& tolerance)
+  {
+    m_tolerance = tolerance;
+    return derived();
+  }
+
+  /** \returns a read-write reference to the preconditioner for custom configuration. */
+  Preconditioner& preconditioner() { return m_preconditioner; }
+  
+  /** \returns a read-only reference to the preconditioner. */
+  const Preconditioner& preconditioner() const { return m_preconditioner; }
+
+  /** \returns the max number of iterations */
+  int maxIterations() const
+  {
+    return (mp_matrix && m_maxIterations<0) ? mp_matrix->cols() : m_maxIterations;
+  }
+  
+  /** Sets the max number of iterations */
+  Derived& setMaxIterations(int maxIters)
+  {
+    m_maxIterations = maxIters;
+    return derived();
+  }
+
+  /** \returns the number of iterations performed during the last solve */
+  int iterations() const
+  {
+    eigen_assert(m_isInitialized && "ConjugateGradient is not initialized.");
+    return m_iterations;
+  }
+
+  /** \returns the tolerance error reached during the last solve */
+  RealScalar error() const
+  {
+    eigen_assert(m_isInitialized && "ConjugateGradient is not initialized.");
+    return m_error;
+  }
+
+  /** \returns the solution x of \f$ A x = b \f$ using the current decomposition of A.
+    *
+    * \sa compute()
+    */
+  template<typename Rhs> inline const internal::solve_retval<Derived, Rhs>
+  solve(const MatrixBase<Rhs>& b) const
+  {
+    eigen_assert(m_isInitialized && "IterativeSolverBase is not initialized.");
+    eigen_assert(rows()==b.rows()
+              && "IterativeSolverBase::solve(): invalid number of rows of the right hand side matrix b");
+    return internal::solve_retval<Derived, Rhs>(derived(), b.derived());
+  }
+  
+  /** \returns the solution x of \f$ A x = b \f$ using the current decomposition of A.
+    *
+    * \sa compute()
+    */
+  template<typename Rhs>
+  inline const internal::sparse_solve_retval<IterativeSolverBase, Rhs>
+  solve(const SparseMatrixBase<Rhs>& b) const
+  {
+    eigen_assert(m_isInitialized && "IterativeSolverBase is not initialized.");
+    eigen_assert(rows()==b.rows()
+              && "IterativeSolverBase::solve(): invalid number of rows of the right hand side matrix b");
+    return internal::sparse_solve_retval<IterativeSolverBase, Rhs>(*this, b.derived());
+  }
+
+  /** \returns Success if the iterations converged, and NoConvergence otherwise. */
+  ComputationInfo info() const
+  {
+    eigen_assert(m_isInitialized && "IterativeSolverBase is not initialized.");
+    return m_info;
+  }
+  
+  /** \internal */
+  template<typename Rhs, typename DestScalar, int DestOptions, typename DestIndex>
+  void _solve_sparse(const Rhs& b, SparseMatrix<DestScalar,DestOptions,DestIndex> &dest) const
+  {
+    eigen_assert(rows()==b.rows());
+    
+    int rhsCols = b.cols();
+    int size = b.rows();
+    Eigen::Matrix<DestScalar,Dynamic,1> tb(size);
+    Eigen::Matrix<DestScalar,Dynamic,1> tx(size);
+    for(int k=0; k<rhsCols; ++k)
+    {
+      tb = b.col(k);
+      tx = derived().solve(tb);
+      dest.col(k) = tx.sparseView(0);
+    }
+  }
+
+protected:
+  void init()
+  {
+    m_isInitialized = false;
+    m_analysisIsOk = false;
+    m_factorizationIsOk = false;
+    m_maxIterations = -1;
+    m_tolerance = NumTraits<Scalar>::epsilon();
+  }
+  const MatrixType* mp_matrix;
+  Preconditioner m_preconditioner;
+
+  int m_maxIterations;
+  RealScalar m_tolerance;
+  
+  mutable RealScalar m_error;
+  mutable int m_iterations;
+  mutable ComputationInfo m_info;
+  mutable bool m_isInitialized, m_analysisIsOk, m_factorizationIsOk;
+};
+
+namespace internal {
+ 
+template<typename Derived, typename Rhs>
+struct sparse_solve_retval<IterativeSolverBase<Derived>, Rhs>
+  : sparse_solve_retval_base<IterativeSolverBase<Derived>, Rhs>
+{
+  typedef IterativeSolverBase<Derived> Dec;
+  EIGEN_MAKE_SPARSE_SOLVE_HELPERS(Dec,Rhs)
+
+  template<typename Dest> void evalTo(Dest& dst) const
+  {
+    dec().derived()._solve_sparse(rhs(),dst);
+  }
+};
+
+} // end namespace internal
+
+} // end namespace Eigen
+
+#endif // EIGEN_ITERATIVE_SOLVER_BASE_H