syssolver_linop_cg_array.h

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// -*- C++ -*-
/*! \file
 *  \brief Solve a M*psi=chi linear system by CG2
 */
 
#ifndef __syssolver_linop_cg_array_h__
#define __syssolver_linop_cg_array_h__
 
#include "chroma_config.h"
#include "handle.h"
#include "syssolver.h"
#include "linearop.h"
#include "actions/ferm/invert/syssolver_linop.h"
#include "actions/ferm/invert/syssolver_cg_params.h"
#include "actions/ferm/invert/invcg2_array.h"
 
 
namespace Chroma
{
 
  //! CG1 system solver namespace
  namespace LinOpSysSolverCGArrayEnv
  {
    //! Register the syssolver
    bool registerAll();
  }
 
 
  //! Solve a M*psi=chi linear system by CG2
  /*! \ingroup invert
   */
  template<typename T>
  class LinOpSysSolverCGArray : public LinOpSystemSolverArray<T>
  {
  public:
    //! Constructor
    /*!
     * \param M_        Linear operator ( Read )
     * \param invParam  inverter parameters ( Read )
     */
    LinOpSysSolverCGArray(Handle< LinearOperatorArray<T> > A_,
                          const SysSolverCGParams& invParam_) : 
      A(A_), invParam(invParam_) 
      {}
 
    //! Destructor is automatic
    ~LinOpSysSolverCGArray() {}
 
    //! Expected length of array index
    int size() const {return A->size();}
 
    //! Return the subset on which the operator acts
    const Subset& subset() const {return A->subset();}
 
    //! Solver the linear system
    /*!
     * \param psi      solution ( Modify )
     * \param chi      source ( Read )
     * \return syssolver results
     */
    SystemSolverResults_t operator() (multi1d<T>& psi, const multi1d<T>& chi) const
      {
        START_CODE();
 
        multi1d<T> chi_tmp(size());
        (*A)(chi_tmp, chi, MINUS);
 
        SystemSolverResults_t res;  // initialized by a constructor
        {
 
          res = InvCG2(*A, chi_tmp, psi, invParam.RsdCG, invParam.MaxCG);
        
 
#ifdef CHROMA_DO_ONE_CG_RESTART
 
          int n_count = res.n_count;
 
          // One automatic restart (if enabled)
          res = InvCG2(*A, chi_tmp, psi, invParam.RsdCGRestart, invParam.MaxCGRestart);
          res.n_count += n_count;
#endif
 
        }
 
        END_CODE();
 
        return res;
      }
 
 
  private:
    // Hide default constructor
    LinOpSysSolverCGArray() {}
 
    Handle< LinearOperatorArray<T> > A;
    SysSolverCGParams invParam;
  };
 
 
} // End namespace
 
#endif