lwldslash_array_w.cc

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/*! \file
 *  \brief Wilson Dslash linear operator array
 */
 
#include "chromabase.h"
#include "actions/ferm/linop/lwldslash_array_w.h"
 
 
namespace Chroma 
{ 
  //! General Wilson-Dirac dslash of arrays
  /*! \ingroup linop
   * DSLASH
   *
   * This routine is specific to Wilson fermions!
   *
   * Description:
   *
   * This routine applies the operator D' to Psi, putting the result in Chi.
   *
   *           Nd-1
   *           ---
   *           \
   *   chi(x)  :=  >  U  (x) (1 - isign gamma  ) psi(x+mu)
   *           /    mu                    mu
   *           ---
   *           mu=0
   *
   *                 Nd-1
   *                 ---
   *                 \    +
   *                +    >  U  (x-mu) (1 + isign gamma  ) psi(x-mu)
   *                 /    mu                       mu
   *                 ---
   *                 mu=0
   *
   */
 
 
  //! Creation routine
  void QDPWilsonDslashArray::create(Handle< FermState<T,P,Q> > state, int N5_)
  {
    multi1d<Real> cf(Nd);
    cf = 1.0;
    create(state, N5_, cf);
  }
 
 
  //! Creation routine with anisotropy
  void QDPWilsonDslashArray::create(Handle< FermState<T,P,Q> > state, int N5_,
                                    const AnisoParam_t& anisoParam) 
  {
    START_CODE();
 
    create(state, N5_, makeFermCoeffs(anisoParam));
 
    END_CODE();
  }
 
  //! Creation routine
  void QDPWilsonDslashArray::create(Handle< FermState<T,P,Q> > state, int N5_,
                                    const multi1d<Real>& coeffs_)
  {
    START_CODE();
 
    N5 = N5_;
    coeffs = coeffs_;
 
    // Save a copy of the fermbc
    fbc = state->getFermBC();
 
    // Sanity check
    if (fbc.operator->() == 0)
    {
      QDPIO::cerr << "WilsonDslashArray: error: fbc is null" << std::endl;
      QDP_abort(1);
    }
 
    // Get links
    u = state->getLinks();
  
    // Rescale the u fields by the anisotropy
    for(int mu=0; mu < u.size(); ++mu)
    {
      u[mu] *= coeffs[mu];
    }
 
    END_CODE();
  }
 
 
  //! General Wilson-Dirac dslash
  /*! \ingroup linop
   * Wilson dslash
   *
   * Arguments:
   *
   *  \param chi      Result                                            (Write)
   *  \param psi      Pseudofermion field                               (Read)
   *  \param isign    D'^dag or D' ( MINUS | PLUS ) resp.               (Read)
   *  \param cb       Checkerboard of OUTPUT std::vector                        (Read) 
   */
  void 
  QDPWilsonDslashArray::apply (multi1d<LatticeFermion>& chi, 
                               const multi1d<LatticeFermion>& psi, 
                               enum PlusMinus isign, int cb) const
  {
    START_CODE();
 
    if( chi.size() != N5 ) chi.resize(N5);
 
    for(int n=0; n < N5; ++n)
      apply(chi[n], psi[n], isign, cb);
 
    END_CODE();
  }
 
 
 
  //! General Wilson-Dirac dslash
  /*! \ingroup linop
   * Wilson dslash
   *
   * Arguments:
   *
   *  \param chi              Result                                            (Write)
   *  \param psi              Pseudofermion field                               (Read)
   *  \param isign      D'^dag or D' ( MINUS | PLUS ) resp.             (Read)
   *  \param cb       Checkerboard of OUTPUT std::vector                        (Read) 
   */
  void 
  QDPWilsonDslashArray::apply (LatticeFermion& chi, const LatticeFermion& psi, 
                               enum PlusMinus isign, int cb) const
  {
    START_CODE();
#if QDP_NC == 3
    /*     F 
     *   a2  (x)  :=  U  (x) (1 - isign gamma  ) psi(x)
     *     mu          mu                    mu
     */
    /*     B           +
     *   a2  (x)  :=  U  (x-mu) (1 + isign gamma  ) psi(x-mu)
     *     mu          mu                       mu
     */
    // Recontruct the bottom two spinor components from the top two
    /*                        F           B
     *   chi(x) :=  sum_mu  a2  (x)  +  a2  (x)
     *                        mu          mu
     */
 
    /* Why are these lines split? An array syntax would help, but the problem is deeper.
     * The expression templates require NO variable args (like int's) to a function
     * and all args must be known at compile time. Hence, the function names carry
     * (as functions usually do) the meaning (and implicit args) to a function.
     */
    switch (isign)
    {
    case PLUS:
      chi[rb[cb]] = spinReconstructDir0Minus(u[0] * shift(spinProjectDir0Minus(psi), FORWARD, 0))
        + spinReconstructDir0Plus(shift(adj(u[0]) * spinProjectDir0Plus(psi), BACKWARD, 0))
#if QDP_ND >= 2
        + spinReconstructDir1Minus(u[1] * shift(spinProjectDir1Minus(psi), FORWARD, 1))
        + spinReconstructDir1Plus(shift(adj(u[1]) * spinProjectDir1Plus(psi), BACKWARD, 1))
#endif
#if QDP_ND >= 3
        + spinReconstructDir2Minus(u[2] * shift(spinProjectDir2Minus(psi), FORWARD, 2))
        + spinReconstructDir2Plus(shift(adj(u[2]) * spinProjectDir2Plus(psi), BACKWARD, 2))
#endif
#if QDP_ND >= 4
        + spinReconstructDir3Minus(u[3] * shift(spinProjectDir3Minus(psi), FORWARD, 3))
        + spinReconstructDir3Plus(shift(adj(u[3]) * spinProjectDir3Plus(psi), BACKWARD, 3))
#endif
#if QDP_ND >= 5
#error "Unsupported number of dimensions"
#endif
        ;
      break;
 
    case MINUS:
      chi[rb[cb]] = spinReconstructDir0Plus(u[0] * shift(spinProjectDir0Plus(psi), FORWARD, 0))
        + spinReconstructDir0Minus(shift(adj(u[0]) * spinProjectDir0Minus(psi), BACKWARD, 0))
#if QDP_ND >= 2
        + spinReconstructDir1Plus(u[1] * shift(spinProjectDir1Plus(psi), FORWARD, 1))
        + spinReconstructDir1Minus(shift(adj(u[1]) * spinProjectDir1Minus(psi), BACKWARD, 1))
#endif
#if QDP_ND >= 3
        + spinReconstructDir2Plus(u[2] * shift(spinProjectDir2Plus(psi), FORWARD, 2))
        + spinReconstructDir2Minus(shift(adj(u[2]) * spinProjectDir2Minus(psi), BACKWARD, 2))
#endif
#if QDP_ND >= 4
        + spinReconstructDir3Plus(u[3] * shift(spinProjectDir3Plus(psi), FORWARD, 3))
        + spinReconstructDir3Minus(shift(adj(u[3]) * spinProjectDir3Minus(psi), BACKWARD, 3))
#endif
#if QDP_ND >= 5
#error "Unsupported number of dimensions"
#endif
        ;
      break;
 
    }
 
    getFermBC().modifyF(chi, QDP::rb[cb]);
#else
    QDPIO::cerr<<"lwldslash_array_w: not implemented for NC!=3\n";
    QDP_abort(13) ;
#endif
 
    END_CODE();
  }
 
} // End Namespace Chroma