1 // This file is part of Eigen, a lightweight C++ template library
2 // for linear algebra.
3 //
4 // Copyright (C) 2012 Désiré Nuentsa-Wakam <desire.nuentsa_wakam@inria.fr>
5 // Copyright (C) 2012 Gael Guennebaud <gael.guennebaud@inria.fr>
6 //
7 // This Source Code Form is subject to the terms of the Mozilla
8 // Public License v. 2.0. If a copy of the MPL was not distributed
9 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
10
11 #ifndef SPARSELU_KERNEL_BMOD_H
12 #define SPARSELU_KERNEL_BMOD_H
13
14 namespace Eigen {
15 namespace internal {
16
17 /**
18 * \brief Performs numeric block updates from a given supernode to a single column
19 *
20 * \param segsize Size of the segment (and blocks ) to use for updates
21 * \param[in,out] dense Packed values of the original matrix
22 * \param tempv temporary vector to use for updates
23 * \param lusup array containing the supernodes
24 * \param lda Leading dimension in the supernode
25 * \param nrow Number of rows in the rectangular part of the supernode
26 * \param lsub compressed row subscripts of supernodes
27 * \param lptr pointer to the first column of the current supernode in lsub
28 * \param no_zeros Number of nonzeros elements before the diagonal part of the supernode
29 * \return 0 on success
30 */
31 template <int SegSizeAtCompileTime> struct LU_kernel_bmod
32 {
33 template <typename BlockScalarVector, typename ScalarVector, typename IndexVector, typename Index>
34 static EIGEN_DONT_INLINE void run(const int segsize, BlockScalarVector& dense, ScalarVector& tempv, ScalarVector& lusup, Index& luptr, const Index lda,
35 const Index nrow, IndexVector& lsub, const Index lptr, const Index no_zeros);
36 };
37
38 template <int SegSizeAtCompileTime>
39 template <typename BlockScalarVector, typename ScalarVector, typename IndexVector, typename Index>
run(const int segsize,BlockScalarVector & dense,ScalarVector & tempv,ScalarVector & lusup,Index & luptr,const Index lda,const Index nrow,IndexVector & lsub,const Index lptr,const Index no_zeros)40 EIGEN_DONT_INLINE void LU_kernel_bmod<SegSizeAtCompileTime>::run(const int segsize, BlockScalarVector& dense, ScalarVector& tempv, ScalarVector& lusup, Index& luptr, const Index lda,
41 const Index nrow, IndexVector& lsub, const Index lptr, const Index no_zeros)
42 {
43 typedef typename ScalarVector::Scalar Scalar;
44 // First, copy U[*,j] segment from dense(*) to tempv(*)
45 // The result of triangular solve is in tempv[*];
46 // The result of matric-vector update is in dense[*]
47 Index isub = lptr + no_zeros;
48 int i;
49 Index irow;
50 for (i = 0; i < ((SegSizeAtCompileTime==Dynamic)?segsize:SegSizeAtCompileTime); i++)
51 {
52 irow = lsub(isub);
53 tempv(i) = dense(irow);
54 ++isub;
55 }
56 // Dense triangular solve -- start effective triangle
57 luptr += lda * no_zeros + no_zeros;
58 // Form Eigen matrix and vector
59 Map<Matrix<Scalar,SegSizeAtCompileTime,SegSizeAtCompileTime>, 0, OuterStride<> > A( &(lusup.data()[luptr]), segsize, segsize, OuterStride<>(lda) );
60 Map<Matrix<Scalar,SegSizeAtCompileTime,1> > u(tempv.data(), segsize);
61
62 u = A.template triangularView<UnitLower>().solve(u);
63
64 // Dense matrix-vector product y <-- B*x
65 luptr += segsize;
66 const Index PacketSize = internal::packet_traits<Scalar>::size;
67 Index ldl = internal::first_multiple(nrow, PacketSize);
68 Map<Matrix<Scalar,Dynamic,SegSizeAtCompileTime>, 0, OuterStride<> > B( &(lusup.data()[luptr]), nrow, segsize, OuterStride<>(lda) );
69 Index aligned_offset = internal::first_aligned(tempv.data()+segsize, PacketSize);
70 Index aligned_with_B_offset = (PacketSize-internal::first_aligned(B.data(), PacketSize))%PacketSize;
71 Map<Matrix<Scalar,Dynamic,1>, 0, OuterStride<> > l(tempv.data()+segsize+aligned_offset+aligned_with_B_offset, nrow, OuterStride<>(ldl) );
72
73 l.setZero();
74 internal::sparselu_gemm<Scalar>(l.rows(), l.cols(), B.cols(), B.data(), B.outerStride(), u.data(), u.outerStride(), l.data(), l.outerStride());
75
76 // Scatter tempv[] into SPA dense[] as a temporary storage
77 isub = lptr + no_zeros;
78 for (i = 0; i < ((SegSizeAtCompileTime==Dynamic)?segsize:SegSizeAtCompileTime); i++)
79 {
80 irow = lsub(isub++);
81 dense(irow) = tempv(i);
82 }
83
84 // Scatter l into SPA dense[]
85 for (i = 0; i < nrow; i++)
86 {
87 irow = lsub(isub++);
88 dense(irow) -= l(i);
89 }
90 }
91
92 template <> struct LU_kernel_bmod<1>
93 {
94 template <typename BlockScalarVector, typename ScalarVector, typename IndexVector, typename Index>
95 static EIGEN_DONT_INLINE void run(const int /*segsize*/, BlockScalarVector& dense, ScalarVector& /*tempv*/, ScalarVector& lusup, Index& luptr,
96 const Index lda, const Index nrow, IndexVector& lsub, const Index lptr, const Index no_zeros);
97 };
98
99
100 template <typename BlockScalarVector, typename ScalarVector, typename IndexVector, typename Index>
101 EIGEN_DONT_INLINE void LU_kernel_bmod<1>::run(const int /*segsize*/, BlockScalarVector& dense, ScalarVector& /*tempv*/, ScalarVector& lusup, Index& luptr,
102 const Index lda, const Index nrow, IndexVector& lsub, const Index lptr, const Index no_zeros)
103 {
104 typedef typename ScalarVector::Scalar Scalar;
105 Scalar f = dense(lsub(lptr + no_zeros));
106 luptr += lda * no_zeros + no_zeros + 1;
107 const Scalar* a(lusup.data() + luptr);
108 const /*typename IndexVector::Scalar*/Index* irow(lsub.data()+lptr + no_zeros + 1);
109 Index i = 0;
110 for (; i+1 < nrow; i+=2)
111 {
112 Index i0 = *(irow++);
113 Index i1 = *(irow++);
114 Scalar a0 = *(a++);
115 Scalar a1 = *(a++);
116 Scalar d0 = dense.coeff(i0);
117 Scalar d1 = dense.coeff(i1);
118 d0 -= f*a0;
119 d1 -= f*a1;
120 dense.coeffRef(i0) = d0;
121 dense.coeffRef(i1) = d1;
122 }
123 if(i<nrow)
124 dense.coeffRef(*(irow++)) -= f * *(a++);
125 }
126
127 } // end namespace internal
128
129 } // end namespace Eigen
130 #endif // SPARSELU_KERNEL_BMOD_H
131