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mfem/fem/prestriction.cpp
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// Copyright (c) 2010-2020, Lawrence Livermore National Security, LLC. Produced
// at the Lawrence Livermore National Laboratory. All Rights reserved. See files
// LICENSE and NOTICE for details. LLNL-CODE-806117.
//
// This file is part of the MFEM library. For more information and source code
// availability visit https://mfem.org.
//
// MFEM is free software; you can redistribute it and/or modify it under the
// terms of the BSD-3 license. We welcome feedback and contributions, see file
// CONTRIBUTING.md for details.
#include "../config/config.hpp"
#ifdef MFEM_USE_MPI
#include "restriction.hpp"
#include "prestriction.hpp"
#include "pgridfunc.hpp"
#include "pfespace.hpp"
#include "fespace.hpp"
#include "../general/forall.hpp"
namespace mfem
{
ParL2FaceRestriction::ParL2FaceRestriction(const ParFiniteElementSpace &fes,
ElementDofOrdering e_ordering,
FaceType type,
L2FaceValues m)
: L2FaceRestriction(fes, type, m)
{
if (nf==0) { return; }
// If fespace == L2
const ParFiniteElementSpace &pfes =
static_cast<const ParFiniteElementSpace&>(this->fes);
const FiniteElement *fe = pfes.GetFE(0);
const TensorBasisElement *tfe = dynamic_cast<const TensorBasisElement*>(fe);
MFEM_VERIFY(tfe != NULL &&
(tfe->GetBasisType()==BasisType::GaussLobatto ||
tfe->GetBasisType()==BasisType::Positive),
"Only Gauss-Lobatto and Bernstein basis are supported in "
"ParL2FaceRestriction.");
MFEM_VERIFY(pfes.GetMesh()->Conforming(),
"Non-conforming meshes not yet supported with partial assembly.");
// Assuming all finite elements are using Gauss-Lobatto dofs
height = (m==L2FaceValues::DoubleValued? 2 : 1)*vdim*nf*dof;
width = pfes.GetVSize();
const bool dof_reorder = (e_ordering == ElementDofOrdering::LEXICOGRAPHIC);
if (!dof_reorder)
{
mfem_error("Non-Tensor L2FaceRestriction not yet implemented.");
}
if (dof_reorder && nf > 0)
{
for (int f = 0; f < pfes.GetNF(); ++f)
{
const FiniteElement *fe =
pfes.GetTraceElement(f, pfes.GetMesh()->GetFaceBaseGeometry(f));
const TensorBasisElement* el =
dynamic_cast<const TensorBasisElement*>(fe);
if (el) { continue; }
mfem_error("Finite element not suitable for lexicographic ordering");
}
}
const Table& e2dTable = pfes.GetElementToDofTable();
const int* elementMap = e2dTable.GetJ();
Array<int> faceMap1(dof), faceMap2(dof);
int e1, e2;
int inf1, inf2;
int face_id1, face_id2;
int orientation;
const int dof1d = pfes.GetFE(0)->GetOrder()+1;
const int elem_dofs = pfes.GetFE(0)->GetDof();
const int dim = pfes.GetMesh()->SpaceDimension();
// Computation of scatter indices
int f_ind=0;
for (int f = 0; f < pfes.GetNF(); ++f)
{
pfes.GetMesh()->GetFaceElements(f, &e1, &e2);
pfes.GetMesh()->GetFaceInfos(f, &inf1, &inf2);
if (dof_reorder)
{
orientation = inf1 % 64;
face_id1 = inf1 / 64;
GetFaceDofs(dim, face_id1, dof1d, faceMap1); // only for hex
orientation = inf2 % 64;
face_id2 = inf2 / 64;
GetFaceDofs(dim, face_id2, dof1d, faceMap2); // only for hex
}
else
{
mfem_error("FaceRestriction not yet implemented for this type of "
"element.");
// TODO Something with GetFaceDofs?
orientation = 0; // suppress compiler warning
face_id1 = face_id2 = 0; // suppress compiler warning
}
if (type==FaceType::Interior &&
(e2>=0 || (e2<0 && inf2>=0) )) // interior/shared face
{
for (int d = 0; d < dof; ++d)
{
const int face_dof = faceMap1[d];
const int did = face_dof;
const int gid = elementMap[e1*elem_dofs + did];
const int lid = dof*f_ind + d;
scatter_indices1[lid] = gid;
}
if (m==L2FaceValues::DoubleValued)
{
if (e2>=0) // interior face
{
for (int d = 0; d < dof; ++d)
{
const int pd = PermuteFaceL2(dim, face_id1, face_id2,
orientation, dof1d, d);
const int face_dof = faceMap2[pd];
const int did = face_dof;
const int gid = elementMap[e2*elem_dofs + did];
const int lid = dof*f_ind + d;
scatter_indices2[lid] = gid;
}
}
else if (inf2>=0) // shared boundary
{
const int se2 = -1 - e2;
Array<int> sharedDofs;
pfes.GetFaceNbrElementVDofs(se2, sharedDofs);
for (int d = 0; d < dof; ++d)
{
const int pd = PermuteFaceL2(dim, face_id1, face_id2,
orientation, dof1d, d);
const int face_dof = faceMap2[pd];
const int did = face_dof;
const int gid = sharedDofs[did];
const int lid = dof*f_ind + d;
// Trick to differentiate dof location inter/shared
scatter_indices2[lid] = ndofs+gid;
}
}
}
f_ind++;
}
else if (type==FaceType::Boundary && e2<0 && inf2<0) // true boundary
{
for (int d = 0; d < dof; ++d)
{
const int face_dof = faceMap1[d];
const int did = face_dof;
const int gid = elementMap[e1*elem_dofs + did];
const int lid = dof*f_ind + d;
scatter_indices1[lid] = gid;
}
if (m==L2FaceValues::DoubleValued)
{
for (int d = 0; d < dof; ++d)
{
const int lid = dof*f_ind + d;
scatter_indices2[lid] = -1;
}
}
f_ind++;
}
}
MFEM_VERIFY(f_ind==nf, "Unexpected number of faces.");
// Computation of gather_indices
for (int i = 0; i <= ndofs; ++i)
{
offsets[i] = 0;
}
f_ind = 0;
for (int f = 0; f < pfes.GetNF(); ++f)
{
pfes.GetMesh()->GetFaceElements(f, &e1, &e2);
pfes.GetMesh()->GetFaceInfos(f, &inf1, &inf2);
if ((type==FaceType::Interior && (e2>=0 || (e2<0 && inf2>=0))) ||
(type==FaceType::Boundary && e2<0 && inf2<0) )
{
orientation = inf1 % 64;
face_id1 = inf1 / 64;
GetFaceDofs(dim, face_id1, dof1d, faceMap1);
orientation = inf2 % 64;
face_id2 = inf2 / 64;
GetFaceDofs(dim, face_id2, dof1d, faceMap2);
for (int d = 0; d < dof; ++d)
{
const int did = faceMap1[d];
const int gid = elementMap[e1*elem_dofs + did];
++offsets[gid + 1];
}
if (m==L2FaceValues::DoubleValued)
{
for (int d = 0; d < dof; ++d)
{
if (type==FaceType::Interior && e2>=0) // interior face
{
const int pd = PermuteFaceL2(dim, face_id1, face_id2,
orientation, dof1d, d);
const int did = faceMap2[pd];
const int gid = elementMap[e2*elem_dofs + did];
++offsets[gid + 1];
}
}
}
f_ind++;
}
}
MFEM_VERIFY(f_ind==nf, "Unexpected number of faces.");
for (int i = 1; i <= ndofs; ++i)
{
offsets[i] += offsets[i - 1];
}
f_ind = 0;
for (int f = 0; f < pfes.GetNF(); ++f)
{
pfes.GetMesh()->GetFaceElements(f, &e1, &e2);
pfes.GetMesh()->GetFaceInfos(f, &inf1, &inf2);
if ((type==FaceType::Interior && (e2>=0 || (e2<0 && inf2>=0))) ||
(type==FaceType::Boundary && e2<0 && inf2<0) )
{
orientation = inf1 % 64;
face_id1 = inf1 / 64;
GetFaceDofs(dim, face_id1, dof1d, faceMap1);
orientation = inf2 % 64;
face_id2 = inf2 / 64;
GetFaceDofs(dim, face_id2, dof1d, faceMap2);
for (int d = 0; d < dof; ++d)
{
const int did = faceMap1[d];
const int gid = elementMap[e1*elem_dofs + did];
const int lid = dof*f_ind + d;
// We don't shift lid to express that it's e1 of f
gather_indices[offsets[gid]++] = lid;
}
if (m==L2FaceValues::DoubleValued)
{
for (int d = 0; d < dof; ++d)
{
if (type==FaceType::Interior && e2>=0) // interior face
{
const int pd = PermuteFaceL2(dim, face_id1, face_id2,
orientation, dof1d, d);
const int did = faceMap2[pd];
const int gid = elementMap[e2*elem_dofs + did];
const int lid = dof*f_ind + d;
// We shift lid to express that it's e2 of f
gather_indices[offsets[gid]++] = nfdofs + lid;
}
}
}
f_ind++;
}
}
MFEM_VERIFY(f_ind==nf, "Unexpected number of faces.");
for (int i = ndofs; i > 0; --i)
{
offsets[i] = offsets[i - 1];
}
offsets[0] = 0;
}
void ParL2FaceRestriction::Mult(const Vector& x, Vector& y) const
{
const ParFiniteElementSpace &pfes =
static_cast<const ParFiniteElementSpace&>(this->fes);
ParGridFunction x_gf;
x_gf.MakeRef(const_cast<ParFiniteElementSpace*>(&pfes),
const_cast<Vector&>(x), 0);
x_gf.ExchangeFaceNbrData();
// Assumes all elements have the same number of dofs
const int nd = dof;
const int vd = vdim;
const bool t = byvdim;
const int threshold = ndofs;
if (m==L2FaceValues::DoubleValued)
{
auto d_indices1 = scatter_indices1.Read();
auto d_indices2 = scatter_indices2.Read();
auto d_x = Reshape(x.Read(), t?vd:ndofs, t?ndofs:vd);
auto d_x_shared = Reshape(x_gf.FaceNbrData().Read(),
t?vd:ndofs, t?ndofs:vd);
auto d_y = Reshape(y.Write(), nd, vd, 2, nf);
MFEM_FORALL(i, nfdofs,
{
const int dof = i % nd;
const int face = i / nd;
const int idx1 = d_indices1[i];
for (int c = 0; c < vd; ++c)
{
d_y(dof, c, 0, face) = d_x(t?c:idx1, t?idx1:c);
}
const int idx2 = d_indices2[i];
for (int c = 0; c < vd; ++c)
{
if (idx2>-1 && idx2<threshold) // interior face
{
d_y(dof, c, 1, face) = d_x(t?c:idx2, t?idx2:c);
}
else if (idx2>=threshold) // shared boundary
{
d_y(dof, c, 1, face) = d_x_shared(t?c:(idx2-threshold),
t?(idx2-threshold):c);
}
else // true boundary
{
d_y(dof, c, 1, face) = 0.0;
}
}
});
}
else
{
auto d_indices1 = scatter_indices1.Read();
auto d_x = Reshape(x.Read(), t?vd:ndofs, t?ndofs:vd);
auto d_y = Reshape(y.Write(), nd, vd, nf);
MFEM_FORALL(i, nfdofs,
{
const int dof = i % nd;
const int face = i / nd;
const int idx1 = d_indices1[i];
for (int c = 0; c < vd; ++c)
{
d_y(dof, c, face) = d_x(t?c:idx1, t?idx1:c);
}
});
}
}
static MFEM_HOST_DEVICE int AddNnz(const int iE, int *I, const int dofs)
{
int val = AtomicAdd(I[iE],dofs);
return val;
}
void ParL2FaceRestriction::FillI(SparseMatrix &mat,
SparseMatrix &face_mat) const
{
const int face_dofs = dof;
const int Ndofs = ndofs;
auto d_indices1 = scatter_indices1.Read();
auto d_indices2 = scatter_indices2.Read();
auto I = mat.ReadWriteI();
auto I_face = face_mat.ReadWriteI();
MFEM_FORALL(i, ne*elemDofs*vdim+1,
{
I_face[i] = 0;
});
MFEM_FORALL(fdof, nf*face_dofs,
{
const int f = fdof/face_dofs;
const int iF = fdof%face_dofs;
const int iE1 = d_indices1[f*face_dofs+iF];
if (iE1 < Ndofs)
{
for (int jF = 0; jF < face_dofs; jF++)
{
const int jE2 = d_indices2[f*face_dofs+jF];
if (jE2 < Ndofs)
{
AddNnz(iE1,I,1);
}
else
{
AddNnz(iE1,I_face,1);
}
}
}
const int iE2 = d_indices2[f*face_dofs+iF];
if (iE2 < Ndofs)
{
for (int jF = 0; jF < face_dofs; jF++)
{
const int jE1 = d_indices1[f*face_dofs+jF];
if (jE1 < Ndofs)
{
AddNnz(iE2,I,1);
}
else
{
AddNnz(iE2,I_face,1);
}
}
}
});
}
void ParL2FaceRestriction::FillJAndData(const Vector &ea_data,
SparseMatrix &mat,
SparseMatrix &face_mat) const
{
const int face_dofs = dof;
const int Ndofs = ndofs;
auto d_indices1 = scatter_indices1.Read();
auto d_indices2 = scatter_indices2.Read();
auto mat_fea = Reshape(ea_data.Read(), face_dofs, face_dofs, 2, nf);
auto I = mat.ReadWriteI();
auto I_face = face_mat.ReadWriteI();
auto J = mat.WriteJ();
auto J_face = face_mat.WriteJ();
auto Data = mat.WriteData();
auto Data_face = face_mat.WriteData();
MFEM_FORALL(fdof, nf*face_dofs,
{
const int f = fdof/face_dofs;
const int iF = fdof%face_dofs;
const int iE1 = d_indices1[f*face_dofs+iF];
if (iE1 < Ndofs)
{
for (int jF = 0; jF < face_dofs; jF++)
{
const int jE2 = d_indices2[f*face_dofs+jF];
if (jE2 < Ndofs)
{
const int offset = AddNnz(iE1,I,1);
J[offset] = jE2;
Data[offset] = mat_fea(jF,iF,1,f);
}
else
{
const int offset = AddNnz(iE1,I_face,1);
J_face[offset] = jE2-Ndofs;
Data_face[offset] = mat_fea(jF,iF,1,f);
}
}
}
const int iE2 = d_indices2[f*face_dofs+iF];
if (iE2 < Ndofs)
{
for (int jF = 0; jF < face_dofs; jF++)
{
const int jE1 = d_indices1[f*face_dofs+jF];
if (jE1 < Ndofs)
{
const int offset = AddNnz(iE2,I,1);
J[offset] = jE1;
Data[offset] = mat_fea(jF,iF,0,f);
}
else
{
const int offset = AddNnz(iE2,I_face,1);
J_face[offset] = jE1-Ndofs;
Data_face[offset] = mat_fea(jF,iF,0,f);
}
}
}
});
}
} // namespace mfem
#endif