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#include <WarpXAlgorithmSelection.H>
#include<FiniteDifferenceAlgorithms/YeeAlgorithm.H>
#include<FiniteDifferenceSolver.H>
#include<AMReX_Gpu.H>
using namespace amrex;
void FiniteDifferenceSolver::EvolveB ( VectorField& Bfield,
VectorField& Efield,
amrex::Real dt ) {
// Select algorithm (The choice of algorithm is a runtime option,
// but we compile code for each algorithm, using templates)
if (m_fdtd_algo == MaxwellSolverAlgo::Yee){
EvolveBwithAlgo <YeeAlgorithm> ( Bfield, Efield, dt );
// } else if (fdtd_algo == MaxwellSolverAlgo::CKC) {
// EvolveBwithAlgo <CKCAlgorithm> ( Bfield, Efield, dt );
} else {
amrex::Abort("Unknown algorithm");
}
}
template<typename algo>
void FiniteDifferenceSolver::EvolveBwithAlgo ( VectorField& Bfield,
VectorField& Efield,
amrex::Real dt ) {
// Loop through the grids, and over the tiles within each grid
#ifdef _OPENMP
#pragma omp parallel if (amrex::Gpu::notInLaunchRegion())
#endif
for ( MFIter mfi(*Bfield[0], TilingIfNotGPU()); mfi.isValid(); ++mfi ) {
// Extract field data for this grid/tile
auto const& Bx = Bfield[0]->array(mfi);
auto const& By = Bfield[1]->array(mfi);
auto const& Bz = Bfield[2]->array(mfi);
auto const& Ex = Efield[0]->array(mfi);
auto const& Ey = Efield[1]->array(mfi);
auto const& Ez = Efield[2]->array(mfi);
// Extract stencil coefficients
Real const* AMREX_RESTRICT coefs_x = stencil_coefs_x.dataPtr();
int const n_coefs_x = stencil_coefs_x.size();
Real const* AMREX_RESTRICT coefs_y = stencil_coefs_y.dataPtr();
int const n_coefs_y = stencil_coefs_y.size();
Real const* AMREX_RESTRICT coefs_z = stencil_coefs_z.dataPtr();
int const n_coefs_z = stencil_coefs_z.size();
// Extract tileboxes for which to loop
const Box& tbx = mfi.tilebox(Bfield[0]->ixType().ixType());
const Box& tby = mfi.tilebox(Bfield[1]->ixType().ixType());
const Box& tbz = mfi.tilebox(Bfield[2]->ixType().ixType());
// Loop over the cells and update the fields
amrex::ParallelFor(tbx, tby, tbz,
[=] AMREX_GPU_DEVICE (int i, int j, int k){
Bx(i, j, k) += dt * algo::UpwardDz(Ey, coefs_z, n_coefs_z, i, j, k)
- dt * algo::UpwardDy(Ez, coefs_y, n_coefs_y, i, j, k);
},
[=] AMREX_GPU_DEVICE (int i, int j, int k){
By(i, j, k) += dt * algo::UpwardDx(Ez, coefs_x, n_coefs_x, i, j, k)
- dt * algo::UpwardDz(Ex, coefs_z, n_coefs_z, i, j, k);
},
[=] AMREX_GPU_DEVICE (int i, int j, int k){
Bz(i, j, k) += dt * algo::UpwardDy(Ex, coefs_y, n_coefs_y, i, j, k)
- dt * algo::UpwardDx(Ey, coefs_x, n_coefs_x, i, j, k);
}
);
}
}
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