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 is expected to define precomputeQpResidual() and precomputeQpJacobian() instead of
      27             :  * computeQpResidual() and computeQpJacobian(). The signature of precomputeQpResidual() expected to
      28             :  * be defined in 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 precomputeQpResidual(const unsigned int qp,
      36             :  *                                            ResidualDatum & datum) const;
      37             :  *
      38             :  * The signature of precomputeQpJacobian() can be found in the code below. The definition of
      39             :  * computeQpOffDiagJacobian() is still the same with the original Kokkos kernel.
      40             :  */
      41             : template <typename Derived>
      42             : class KernelGrad : public Kernel<Derived>
      43             : {
      44             :   usingKokkosKernelMembers(Derived);
      45             : 
      46             : public:
      47             :   static InputParameters validParams();
      48             : 
      49             :   /**
      50             :    * Constructor
      51             :    */
      52             :   KernelGrad(const InputParameters & parameters);
      53             : 
      54             :   /**
      55             :    * Default methods to prevent compile errors even when these methods were not defined in the
      56             :    * derived class
      57             :    */
      58             :   ///@{
      59             :   /**
      60             :    * Compute diagonal Jacobian contribution on a quadrature point
      61             :    * @param j The trial function DOF index
      62             :    * @param qp The local quadrature point index
      63             :    * @param datum The ResidualDatum object of the current thread
      64             :    * @returns The vector component of the Jacobian contribution that will be multiplied by the
      65             :    * gradient of the test function
      66             :    */
      67           0 :   KOKKOS_FUNCTION Real3 precomputeQpJacobian(const unsigned int /* j */,
      68             :                                              const unsigned int /* qp */,
      69             :                                              ResidualDatum & /* datum */) const
      70             :   {
      71           0 :     return Real3(0);
      72             :   }
      73             :   ///@}
      74             : 
      75             :   /**
      76             :    * The parallel computation bodies that hide the base class methods to optimize for factoring
      77             :    * out the gradient of test function
      78             :    */
      79             :   ///@{
      80             :   KOKKOS_FUNCTION void computeResidualInternal(const Derived * kernel, ResidualDatum & datum) const;
      81             :   KOKKOS_FUNCTION void computeJacobianInternal(const Derived * kernel, ResidualDatum & datum) const;
      82             :   ///@}
      83             : 
      84             : protected:
      85             :   /**
      86             :    * Get whether precomputeQpJacobian() was not defined in the derived class
      87             :    * @returns Whether precomputeQpJacobian() was not defined in the derived class
      88             :    */
      89          10 :   virtual bool defaultJacobian() const override
      90             :   {
      91          10 :     return &Derived::precomputeQpJacobian == &KernelGrad::precomputeQpJacobian;
      92             :   }
      93             : };
      94             : 
      95             : template <typename Derived>
      96             : InputParameters
      97        9132 : KernelGrad<Derived>::validParams()
      98             : {
      99        9132 :   InputParameters params = Kernel<Derived>::validParams();
     100        9132 :   return params;
     101             : }
     102             : 
     103             : template <typename Derived>
     104          12 : KernelGrad<Derived>::KernelGrad(const InputParameters & parameters) : Kernel<Derived>(parameters)
     105             : {
     106          12 : }
     107             : 
     108             : template <typename Derived>
     109             : KOKKOS_FUNCTION void
     110          96 : KernelGrad<Derived>::computeResidualInternal(const Derived * kernel, ResidualDatum & datum) const
     111             : {
     112          96 :   ResidualObject::computeResidualInternal(
     113             :       datum,
     114          96 :       [&](Real * local_re, const unsigned int ib, const unsigned int ie)
     115             :       {
     116         480 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
     117             :         {
     118         384 :           datum.reinit();
     119             : 
     120         384 :           Real3 value = datum.JxW(qp) * kernel->precomputeQpResidual(qp, datum);
     121             : 
     122        1920 :           for (unsigned int i = ib; i < ie; ++i)
     123        1536 :             local_re[i] += value * _grad_test(datum, i, qp);
     124             :         }
     125             :       });
     126          96 : }
     127             : 
     128             : template <typename Derived>
     129             : KOKKOS_FUNCTION void
     130          24 : KernelGrad<Derived>::computeJacobianInternal(const Derived * kernel, ResidualDatum & datum) const
     131             : {
     132          24 :   Real3 value;
     133             : 
     134          24 :   ResidualObject::computeJacobianInternal(
     135             :       datum,
     136          24 :       [&](Real * local_ke, const unsigned int ijb, const unsigned int ije)
     137             :       {
     138         120 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
     139             :         {
     140          96 :           datum.reinit();
     141             : 
     142          96 :           unsigned int j_old = libMesh::invalid_uint;
     143             : 
     144        1632 :           for (unsigned int ij = ijb; ij < ije; ++ij)
     145             :           {
     146        1536 :             unsigned int i = ij % datum.n_jdofs();
     147        1536 :             unsigned int j = ij / datum.n_jdofs();
     148             : 
     149        1536 :             if (j != j_old)
     150             :             {
     151         384 :               value = datum.JxW(qp) * kernel->precomputeQpJacobian(j, qp, datum);
     152         384 :               j_old = j;
     153             :             }
     154             : 
     155        1536 :             local_ke[ij] += value * _grad_test(datum, i, qp);
     156             :           }
     157             :         }
     158             :       });
     159          24 : }
     160             : 
     161             : } // namespace Kokkos
     162             : } // namespace Moose
     163             : 
     164             : #define usingKokkosKernelGradMembers(T) usingKokkosKernelMembers(T)