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 AssemblyDatum 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             :  *                                         AssemblyDatum & 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 AssemblyDatum 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             :                                           AssemblyDatum & /* 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       37629 :   static auto defaultJacobian() { return &KernelGrad::computeQpJacobian; }
      75             :   ///@}
      76             : 
      77             :   /**
      78             :    * Shims for hook methods that can be leveraged to implement static polymorphism
      79             :    */
      80             :   ///{@
      81             :   template <typename Derived>
      82         384 :   KOKKOS_FUNCTION Real3 computeQpResidualShim(const Derived & kernel,
      83             :                                               const unsigned int qp,
      84             :                                               AssemblyDatum & datum) const
      85             :   {
      86         384 :     return kernel.computeQpResidual(qp, datum);
      87             :   }
      88             :   template <typename Derived>
      89         384 :   KOKKOS_FUNCTION Real3 computeQpJacobianShim(const Derived & kernel,
      90             :                                               const unsigned int j,
      91             :                                               const unsigned int qp,
      92             :                                               AssemblyDatum & datum) const
      93             :   {
      94         384 :     return kernel.computeQpJacobian(j, qp, datum);
      95             :   }
      96             :   ///@}
      97             : 
      98             :   /**
      99             :    * The parallel computation bodies that hide the base class methods to optimize for factoring
     100             :    * out the gradient of test function
     101             :    */
     102             :   ///@{
     103             :   template <typename Derived>
     104             :   KOKKOS_FUNCTION void computeResidualInternal(const Derived & kernel, AssemblyDatum & datum) const;
     105             :   template <typename Derived>
     106             :   KOKKOS_FUNCTION void computeJacobianInternal(const Derived & kernel, AssemblyDatum & datum) const;
     107             :   ///@}
     108             : };
     109             : 
     110             : template <typename Derived>
     111             : KOKKOS_FUNCTION void
     112          96 : KernelGrad::computeResidualInternal(const Derived & kernel, AssemblyDatum & datum) const
     113             : {
     114          96 :   ResidualObject::computeResidualInternal(
     115             :       datum,
     116          96 :       [&](Real * local_re, const unsigned int ib, const unsigned int ie)
     117             :       {
     118         480 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
     119             :         {
     120         384 :           datum.reinit();
     121             : 
     122         384 :           Real3 value = datum.JxW(qp) * kernel.computeQpResidualShim(kernel, qp, datum);
     123             : 
     124        1920 :           for (unsigned int i = ib; i < ie; ++i)
     125        1536 :             local_re[i] += value * _grad_test(datum, i, qp);
     126             :         }
     127             :       });
     128          96 : }
     129             : 
     130             : template <typename Derived>
     131             : KOKKOS_FUNCTION void
     132          24 : KernelGrad::computeJacobianInternal(const Derived & kernel, AssemblyDatum & datum) const
     133             : {
     134          24 :   Real3 value;
     135             : 
     136          24 :   ResidualObject::computeJacobianInternal(
     137             :       datum,
     138          24 :       [&](Real * local_ke, const unsigned int ijb, const unsigned int ije)
     139             :       {
     140         120 :         for (unsigned int qp = 0; qp < datum.n_qps(); ++qp)
     141             :         {
     142          96 :           datum.reinit();
     143             : 
     144          96 :           unsigned int j_old = libMesh::invalid_uint;
     145             : 
     146        1632 :           for (unsigned int ij = ijb; ij < ije; ++ij)
     147             :           {
     148        1536 :             unsigned int i = ij % datum.n_jdofs();
     149        1536 :             unsigned int j = ij / datum.n_jdofs();
     150             : 
     151        1536 :             if (j != j_old)
     152             :             {
     153         384 :               value = datum.JxW(qp) * kernel.computeQpJacobianShim(kernel, j, qp, datum);
     154         384 :               j_old = j;
     155             :             }
     156             : 
     157        1536 :             local_ke[ij] += value * _grad_test(datum, i, qp);
     158             :           }
     159             :         }
     160             :       });
     161          24 : }
     162             : 
     163             : } // namespace Kokkos
     164             : } // namespace Moose