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| 1 | +/** |
| 2 | + * @file CholeskySolverCpu.cpp |
| 3 | + * @author Adham Ibrahim (ibrahimas@ornl.gov) |
| 4 | + * @brief CPU implementation of Cholesky Solver |
| 5 | + */ |
| 6 | + |
| 7 | +#include "CholeskySolverCpu.hpp" |
| 8 | + |
| 9 | +namespace ReSolve |
| 10 | +{ |
| 11 | + using real_type = ReSolve::real_type; |
| 12 | + using out = ReSolve::io::Logger; |
| 13 | + |
| 14 | + namespace hykkt |
| 15 | + { |
| 16 | + CholeskySolverCpu::CholeskySolverCpu() |
| 17 | + { |
| 18 | + Common_.nmethods = 1; |
| 19 | + // Use natural ordering |
| 20 | + Common_.method[0].ordering = CHOLMOD_NATURAL; |
| 21 | + |
| 22 | + A_chol_ = nullptr; |
| 23 | + factorization_ = nullptr; |
| 24 | + cholmod_start(&Common_); |
| 25 | + } |
| 26 | + |
| 27 | + CholeskySolverCpu::~CholeskySolverCpu() |
| 28 | + { |
| 29 | + if (A_chol_) |
| 30 | + { |
| 31 | + cholmod_free_sparse(&A_chol_, &Common_); |
| 32 | + } |
| 33 | + if (factorization_) |
| 34 | + { |
| 35 | + cholmod_free_factor(&factorization_, &Common_); |
| 36 | + } |
| 37 | + cholmod_finish(&Common_); |
| 38 | + } |
| 39 | + |
| 40 | + void CholeskySolverCpu::addMatrixInfo(matrix::Csr* A) |
| 41 | + { |
| 42 | + if (A_chol_) |
| 43 | + { |
| 44 | + cholmod_free_sparse(&A_chol_, &Common_); |
| 45 | + } |
| 46 | + A_chol_ = convertToCholmod(A); |
| 47 | + } |
| 48 | + |
| 49 | + /** |
| 50 | + * @brief Performs symbolic analysis |
| 51 | + * |
| 52 | + * Uses the `cholmod_analyze` routine. |
| 53 | + */ |
| 54 | + void CholeskySolverCpu::symbolicAnalysis() |
| 55 | + { |
| 56 | + factorization_ = cholmod_analyze(A_chol_, &Common_); |
| 57 | + if (Common_.status < 0) |
| 58 | + { |
| 59 | + out::error() << "Cholesky symbolic analysis failed with status: " << Common_.status << "\n"; |
| 60 | + } |
| 61 | + } |
| 62 | + |
| 63 | + /** |
| 64 | + * @brief Performs symbolic analysis |
| 65 | + * @brief Performs numerical factorization |
| 66 | + * |
| 67 | + * Uses the `cholmod_factorize` routine. |
| 68 | + * |
| 69 | + * @param[in] tol - This is ignored in the CPU implementation |
| 70 | + */ |
| 71 | + void CholeskySolverCpu::numericalFactorization(real_type tol) |
| 72 | + { |
| 73 | + (void) tol; // Mark tol as unused |
| 74 | + |
| 75 | + cholmod_factorize(A_chol_, factorization_, &Common_); |
| 76 | + if (Common_.status < 0) |
| 77 | + { |
| 78 | + out::error() << "Cholesky factorization failed with status: " << Common_.status << "\n"; |
| 79 | + } |
| 80 | + } |
| 81 | + |
| 82 | + /** |
| 83 | + * @brief Solves the system Ax = b and stores the result in x. |
| 84 | + * |
| 85 | + * Uses the `cholmod_solve` routine. |
| 86 | + * |
| 87 | + * @param[out] x - The solution vector. |
| 88 | + * @param[in] b - The right-hand side vector. |
| 89 | + */ |
| 90 | + void CholeskySolverCpu::solve(vector::Vector* x, vector::Vector* b) |
| 91 | + { |
| 92 | + cholmod_dense* b_chol = convertToCholmod(b); |
| 93 | + cholmod_dense* x_chol = cholmod_solve(CHOLMOD_A, factorization_, b_chol, &Common_); |
| 94 | + if (Common_.status < 0) |
| 95 | + { |
| 96 | + out::error() << "Cholesky solve failed with status: " << Common_.status << "\n"; |
| 97 | + } |
| 98 | + x->copyDataFrom(static_cast<real_type*>(x_chol->x), memory::HOST, memory::HOST); |
| 99 | + } |
| 100 | + |
| 101 | + /** |
| 102 | + * @brief Converts a ReSolve type CSR matrix to CHOLMOD format. |
| 103 | + * |
| 104 | + * @param[in] A - pointer to the CSR matrix |
| 105 | + * @return Pointer to the equivalent CHOLMOD sparse matrix |
| 106 | + */ |
| 107 | + cholmod_sparse* CholeskySolverCpu::convertToCholmod(matrix::Csr* A) |
| 108 | + { |
| 109 | + A_chol_ = cholmod_allocate_sparse((size_t) A->getNumRows(), |
| 110 | + (size_t) A->getNumColumns(), |
| 111 | + (size_t) A->getNnz(), |
| 112 | + 1, |
| 113 | + 1, |
| 114 | + 1, |
| 115 | + CHOLMOD_REAL, |
| 116 | + &Common_); |
| 117 | + mem_.copyArrayHostToHost( |
| 118 | + static_cast<int*>(A_chol_->p), A->getRowData(memory::HOST), A->getNumRows() + 1); |
| 119 | + mem_.copyArrayHostToHost( |
| 120 | + static_cast<int*>(A_chol_->i), A->getColData(memory::HOST), A->getNnz()); |
| 121 | + mem_.copyArrayHostToHost( |
| 122 | + static_cast<double*>(A_chol_->x), A->getValues(memory::HOST), A->getNnz()); |
| 123 | + |
| 124 | + return A_chol_; |
| 125 | + } |
| 126 | + |
| 127 | + /** |
| 128 | + * @brief Converts a ReSolve type vector to CHOLMOD format. |
| 129 | + * |
| 130 | + * @param[in] v - pointer to the vector |
| 131 | + * @return Pointer to the equivalent CHOLMOD dense matrix |
| 132 | + */ |
| 133 | + cholmod_dense* CholeskySolverCpu::convertToCholmod(vector::Vector* v) |
| 134 | + { |
| 135 | + cholmod_dense* v_chol = cholmod_allocate_dense((size_t) v->getSize(), |
| 136 | + 1, |
| 137 | + (size_t) v->getSize(), |
| 138 | + CHOLMOD_REAL, |
| 139 | + &Common_); |
| 140 | + mem_.copyArrayHostToHost( |
| 141 | + static_cast<double*>(v_chol->x), v->getData(memory::HOST), v->getSize()); |
| 142 | + return v_chol; |
| 143 | + } |
| 144 | + } // namespace hykkt |
| 145 | +} // namespace ReSolve |
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