// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr>
// Copyright (C) 2012 Gael Guennebaud <gael.guennebaud@inria.fr>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
/*
* NOTE: This file is the modified version of [s,d,c,z]panel_bmod.c file in SuperLU
* -- SuperLU routine (version 3.0) --
* Univ. of California Berkeley, Xerox Palo Alto Research Center,
* and Lawrence Berkeley National Lab.
* October 15, 2003
*
* Copyright (c) 1994 by Xerox Corporation. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
* EXPRESSED OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program for any
* purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is
* granted, provided the above notices are retained, and a notice that
* the code was modified is included with the above copyright notice.
*/
#ifndef SPARSELU_PANEL_BMOD_H
#define SPARSELU_PANEL_BMOD_H
namespace Eigen {
namespace internal {
/**
* \brief Performs numeric block updates (sup-panel) in topological order.
*
* Before entering this routine, the original nonzeros in the panel
* were already copied i nto the spa[m,w]
*
* \param m number of rows in the matrix
* \param w Panel size
* \param jcol Starting column of the panel
* \param nseg Number of segments in the U part
* \param dense Store the full representation of the panel
* \param tempv working array
* \param segrep segment representative... first row in the segment
* \param repfnz First nonzero rows
* \param glu Global LU data.
*
*
*/
template <typename Scalar, typename StorageIndex>
void SparseLUImpl<Scalar,StorageIndex>::panel_bmod(const Index m, const Index w, const Index jcol,
const Index nseg, ScalarVector& dense, ScalarVector& tempv,
IndexVector& segrep, IndexVector& repfnz, GlobalLU_t& glu)
{
Index ksub,jj,nextl_col;
Index fsupc, nsupc, nsupr, nrow;
Index krep, kfnz;
Index lptr; // points to the row subscripts of a supernode
Index luptr; // ...
Index segsize,no_zeros ;
// For each nonz supernode segment of U[*,j] in topological order
Index k = nseg - 1;
const Index PacketSize = internal::packet_traits<Scalar>::size;
for (ksub = 0; ksub < nseg; ksub++)
{ // For each updating supernode
/* krep = representative of current k-th supernode
* fsupc = first supernodal column
* nsupc = number of columns in a supernode
* nsupr = number of rows in a supernode
*/
krep = segrep(k); k--;
fsupc = glu.xsup(glu.supno(krep));
nsupc = krep - fsupc + 1;
nsupr = glu.xlsub(fsupc+1) - glu.xlsub(fsupc);
nrow = nsupr - nsupc;
lptr = glu.xlsub(fsupc);
// loop over the panel columns to detect the actual number of columns and rows
Index u_rows = 0;
Index u_cols = 0;
for (jj = jcol; jj < jcol + w; jj++)
{
nextl_col = (jj-jcol) * m;
VectorBlock<IndexVector> repfnz_col(repfnz, nextl_col, m); // First nonzero column index for each row
kfnz = repfnz_col(krep);
if ( kfnz == emptyIdxLU )
continue; // skip any zero segment
segsize = krep - kfnz + 1;
u_cols++;
u_rows = (std::max)(segsize,u_rows);
}
if(nsupc >= 2)
{
Index ldu = internal::first_multiple<Index>(u_rows, PacketSize);
Map<ScalarMatrix, Aligned, OuterStride<> > U(tempv.data(), u_rows, u_cols, OuterStride<>(ldu));
// gather U
Index u_col = 0;
for (jj = jcol; jj < jcol + w; jj++)
{
nextl_col = (jj-jcol) * m;
VectorBlock<IndexVector> repfnz_col(repfnz, nextl_col, m); // First nonzero column index for each row
VectorBlock<ScalarVector> dense_col(dense, nextl_col, m); // Scatter/gather entire matrix column from/to here
kfnz = repfnz_col(krep);
if ( kfnz == emptyIdxLU )
continue; // skip any zero segment
segsize = krep - kfnz + 1;
luptr = glu.xlusup(fsupc);
no_zeros = kfnz - fsupc;
Index isub = lptr + no_zeros;
Index off = u_rows-segsize;
for (Index i = 0; i < off; i++) U(i,u_col) = 0;
for (Index i = 0; i < segsize; i++)
{
Index irow = glu.lsub(isub);
U(i+off,u_col) = dense_col(irow);
++isub;
}
u_col++;
}
// solve U = A^-1 U
luptr = glu.xlusup(fsupc);
Index lda = glu.xlusup(fsupc+1) - glu.xlusup(fsupc);
no_zeros = (krep - u_rows + 1) - fsupc;
luptr += lda * no_zeros + no_zeros;
MappedMatrixBlock A(glu.lusup.data()+luptr, u_rows, u_rows, OuterStride<>(lda) );
U = A.template triangularView<UnitLower>().solve(U);
// update
luptr += u_rows;
MappedMatrixBlock B(glu.lusup.data()+luptr, nrow, u_rows, OuterStride<>(lda) );
eigen_assert(tempv.size()>w*ldu + nrow*w + 1);
Index ldl = internal::first_multiple<Index>(nrow, PacketSize);
Index offset = (PacketSize-internal::first_default_aligned(B.data(), PacketSize)) % PacketSize;
MappedMatrixBlock L(tempv.data()+w*ldu+offset, nrow, u_cols, OuterStride<>(ldl));
L.setZero();
internal::sparselu_gemm<Scalar>(L.rows(), L.cols(), B.cols(), B.data(), B.outerStride(), U.data(), U.outerStride(), L.data(), L.outerStride());
// scatter U and L
u_col = 0;
for (jj = jcol; jj < jcol + w; jj++)
{
nextl_col = (jj-jcol) * m;
VectorBlock<IndexVector> repfnz_col(repfnz, nextl_col, m); // First nonzero column index for each row
VectorBlock<ScalarVector> dense_col(dense, nextl_col, m); // Scatter/gather entire matrix column from/to here
kfnz = repfnz_col(krep);
if ( kfnz == emptyIdxLU )
continue; // skip any zero segment
segsize = krep - kfnz + 1;
no_zeros = kfnz - fsupc;
Index isub = lptr + no_zeros;
Index off = u_rows-segsize;
for (Index i = 0; i < segsize; i++)
{
Index irow = glu.lsub(isub++);
dense_col(irow) = U.coeff(i+off,u_col);
U.coeffRef(i+off,u_col) = 0;
}
// Scatter l into SPA dense[]
for (Index i = 0; i < nrow; i++)
{
Index irow = glu.lsub(isub++);
dense_col(irow) -= L.coeff(i,u_col);
L.coeffRef(i,u_col) = 0;
}
u_col++;
}
}
else // level 2 only
{
// Sequence through each column in the panel
for (jj = jcol; jj < jcol + w; jj++)
{
nextl_col = (jj-jcol) * m;
VectorBlock<IndexVector> repfnz_col(repfnz, nextl_col, m); // First nonzero column index for each row
VectorBlock<ScalarVector> dense_col(dense, nextl_col, m); // Scatter/gather entire matrix column from/to here
kfnz = repfnz_col(krep);
if ( kfnz == emptyIdxLU )
continue; // skip any zero segment
segsize = krep - kfnz + 1;
luptr = glu.xlusup(fsupc);
Index lda = glu.xlusup(fsupc+1)-glu.xlusup(fsupc);// nsupr
// Perform a trianglar solve and block update,
// then scatter the result of sup-col update to dense[]
no_zeros = kfnz - fsupc;
if(segsize==1) LU_kernel_bmod<1>::run(segsize, dense_col, tempv, glu.lusup, luptr, lda, nrow, glu.lsub, lptr, no_zeros);
else if(segsize==2) LU_kernel_bmod<2>::run(segsize, dense_col, tempv, glu.lusup, luptr, lda, nrow, glu.lsub, lptr, no_zeros);
else if(segsize==3) LU_kernel_bmod<3>::run(segsize, dense_col, tempv, glu.lusup, luptr, lda, nrow, glu.lsub, lptr, no_zeros);
else LU_kernel_bmod<Dynamic>::run(segsize, dense_col, tempv, glu.lusup, luptr, lda, nrow, glu.lsub, lptr, no_zeros);
} // End for each column in the panel
}
} // End for each updating supernode
} // end panel bmod
} // end namespace internal
} // end namespace Eigen
#endif // SPARSELU_PANEL_BMOD_H