Line data    Source code

       1             : //* This file is part of the MOOSE framework
       2             : //* https://www.mooseframework.org
       3             : //*
       4             : //* All rights reserved, see COPYRIGHT for full restrictions
       5             : //* https://github.com/idaholab/moose/blob/master/COPYRIGHT
       6             : //*
       7             : //* Licensed under LGPL 2.1, please see LICENSE for details
       8             : //* https://www.gnu.org/licenses/lgpl-2.1.html
       9             : 
      10             : #pragma once
      11             : 
      12             : #include "KokkosKernel.h"
      13             : 
      14             : namespace Moose
      15             : {
      16             : namespace Kokkos
      17             : {
      18             : 
      19             : /**
      20             :  * The base class for a user to derive their own Kokkos kernels where the residual is of the form
      21             :  *
      22             :  * $(\dots, \nabla\psi_i)$
      23             :  *
      24             :  * i.e. the gradient of the test function $(\nabla\psi_i)$ can be factored out for optimization.
      25             :  *
      26             :  * The user should still define computeQpResidual() and computeQpJacobian(), but their signatures
      27             :  * are different from the base class. The signature of computeQpResidual() expected to be defined in
      28             :  * the derived class is as follows:
      29             :  *
      30             :  * @param qp The local quadrature point index
      31             :  * @param datum The ResidualDatum object of the current thread
      32             :  * @returns The vector component of the residual contribution that will be multiplied by the
      33             :  * gradient of the test function
      34             :  *
      35             :  * KOKKOS_FUNCTION Real3 computeQpResidual(const unsigned int qp,
      36             :  *                                         ResidualDatum & datum) const;
      37             :  *
      38             :  * The signature of computeQpJacobian() can be found in the code below. The definition of
      39             :  * computeQpOffDiagJacobian() is still the same with the original Kokkos kernel.
      40             :  */
      41             : class KernelGrad : public Kernel
      42             : {
      43             : public:
      44             :   static InputParameters validParams();
      45             : 
      46             :   /**
      47             :    * Constructor
      48             :    */
      49             :   KernelGrad(const InputParameters & parameters);
      50             : 
      51             :   /**
      52             :    * Default methods to prevent compile errors even when these methods were not defined in the
      53             :    * derived class
      54             :    */
      55             :   ///@{
      56             :   /**
      57             :    * Compute diagonal Jacobian contribution on a quadrature point
      58             :    * @param j The trial function DOF index
      59             :    * @param qp The local quadrature point index
      60             :    * @param datum The ResidualDatum object of the current thread
      61             :    * @returns The vector component of the Jacobian contribution that will be multiplied by the
      62             :    * gradient of the test function
      63             :    */
      64           0 :   KOKKOS_FUNCTION Real3 computeQpJacobian(const unsigned int /* j */,
      65             :                                           const unsigned int /* qp */,
      66             :                                           ResidualDatum & /* datum */) const
      67             :   {
      68           0 :     return Real3(0);
      69             :   }
      70             :   /**
      71             :    * Get the function pointer of the default computeQpJacobian()
      72             :    * @returns The function pointer
      73             :    */
      74       37361 :   static auto defaultJacobian() { return &KernelGrad::computeQpJacobian; }
      75             :   ///@}
      76             : 
      77             :   /**
      78             :    * The parallel computation bodies that hide the base class methods to optimize for factoring
      79             :    * out the gradient of test function
      80             :    */
      81             :   ///@{
      82             :   template <typename Derived>
      83             :   KOKKOS_FUNCTION void computeResidualInternal(const Derived & kernel, ResidualDatum & datum) const;
      84             :   template <typename Derived>
      85             :   KOKKOS_FUNCTION void computeJacobianInternal(const Derived & kernel, ResidualDatum & datum) const;
      86             :   ///@}
      87             : };
      88             : 
      89             : template <typename Derived>
      90             : KOKKOS_FUNCTION void
      91          96 : KernelGrad::computeResidualInternal(const Derived & kernel, ResidualDatum & datum) const
      92             : {
      93          96 :   ResidualObject::computeResidualInternal(
      94             :       datum,
      95          96 :       [&](Real * local_re, const unsigned int ib, const unsigned int ie)
      96             :       {
      97         480 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
      98             :         {
      99         384 :           datum.reinit();
     100             : 
     101         384 :           Real3 value = datum.JxW(qp) * kernel.computeQpResidual(qp, datum);
     102             : 
     103        1920 :           for (unsigned int i = ib; i < ie; ++i)
     104        1536 :             local_re[i] += value * _grad_test(datum, i, qp);
     105             :         }
     106             :       });
     107          96 : }
     108             : 
     109             : template <typename Derived>
     110             : KOKKOS_FUNCTION void
     111          24 : KernelGrad::computeJacobianInternal(const Derived & kernel, ResidualDatum & datum) const
     112             : {
     113          24 :   Real3 value;
     114             : 
     115          24 :   ResidualObject::computeJacobianInternal(
     116             :       datum,
     117          24 :       [&](Real * local_ke, const unsigned int ijb, const unsigned int ije)
     118             :       {
     119         120 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
     120             :         {
     121          96 :           datum.reinit();
     122             : 
     123          96 :           unsigned int j_old = libMesh::invalid_uint;
     124             : 
     125        1632 :           for (unsigned int ij = ijb; ij < ije; ++ij)
     126             :           {
     127        1536 :             unsigned int i = ij % datum.n_jdofs();
     128        1536 :             unsigned int j = ij / datum.n_jdofs();
     129             : 
     130        1536 :             if (j != j_old)
     131             :             {
     132         384 :               value = datum.JxW(qp) * kernel.computeQpJacobian(j, qp, datum);
     133         384 :               j_old = j;
     134             :             }
     135             : 
     136        1536 :             local_ke[ij] += value * _grad_test(datum, i, qp);
     137             :           }
     138             :         }
     139             :       });
     140          24 : }
     141             : 
     142             : } // namespace Kokkos
     143             : } // namespace Moose