Module: ppl/ppl Branch: sparse_matrices Commit: 9ffce899fb3f1f0a87af578413d80b762009dfb6 URL: http://www.cs.unipr.it/git/gitweb.cgi?p=ppl/ppl.git;a=commit;h=9ffce899fb3f1... Author: Marco Poletti <poletti.marco@gmail.com> Date: Mon Mar 22 21:23:32 2010 +0100 PIP_Tree.cc: add an optimized version of sub_assign() for sparse backends with slow insertions. --- src/PIP_Tree.cc | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 70 insertions(+), 0 deletions(-) diff --git a/src/PIP_Tree.cc b/src/PIP_Tree.cc index cbe6925..d1b5dcd 100644 --- a/src/PIP_Tree.cc +++ b/src/PIP_Tree.cc @@ -200,6 +200,8 @@ add_mul_assign_row(PIP_Tree_Node::matrix_row_reference_type x, #endif // !defined(PPL_SPARSE_BACKEND_SLOW_INSERTIONS) +#ifndef PPL_SPARSE_BACKEND_SLOW_INSERTIONS + // Compute x -= y inline void sub_assign(PIP_Tree_Node::matrix_row_reference_type x, @@ -284,6 +286,74 @@ sub_assign(PIP_Tree_Node::matrix_row_reference_type x, } } +#else // !defined(PPL_SPARSE_BACKEND_SLOW_INSERTIONS) + +// Compute x -= y +inline void +sub_assign(PIP_Tree_Node::matrix_row_reference_type x, + PIP_Tree_Node::matrix_row_const_reference_type y) { + PIP_Tree_Node::matrix_row_copy_type row(x.size()); + PIP_Tree_Node::matrix_row_copy_iterator itr = row.end(); + PIP_Tree_Node::matrix_row_const_iterator i = x.begin(); + PIP_Tree_Node::matrix_row_const_iterator i_end = x.end(); + PIP_Tree_Node::matrix_const_row_const_iterator j = y.begin(); + PIP_Tree_Node::matrix_const_row_const_iterator j_end = y.end(); + if (i == i_end && j == j_end) + return; + if (j == j_end + || (i != i_end && (*i).first < (*j).first)) { + itr = row.find_create(*i); + ++i; + } else + if (i == i_end + || (j != j_end && (*i).first > (*j).first)) { + itr = row.find_create(*j); + neg_assign((*itr).second); + ++j; + } else { + PPL_ASSERT(i != i_end); + PPL_ASSERT(j != j_end); + PPL_ASSERT((*i).first == (*j).first); + itr = row.find_create(*i); + (*itr).second -= (*j).second; + ++i; + ++j; + } + PPL_ASSERT(itr != row.end()); + while (i != i_end && j != j_end) { + if ((*i).first < (*j).first) { + itr = row.find_create(*i,itr); + ++i; + } else { + if ((*i).first > (*j).first) { + itr = row.find_create(*j,itr); + neg_assign((*itr).second); + ++j; + } else { + PPL_ASSERT((*i).first == (*j).first); + itr = row.find_create(*i,itr); + (*itr).second -= (*j).second; + ++i; + ++j; + } + } + } + while (i != i_end) { + itr = row.find_create(*i,itr); + ++i; + } + PPL_ASSERT(i == i_end); + while (j != j_end) { + itr = row.find_create(*j,itr); + neg_assign((*itr).second); + ++j; + } + PPL_ASSERT(j == j_end); + std::swap(row,x); +} + +#endif // !defined(PPL_SPARSE_BACKEND_SLOW_INSERTIONS) + // Merge constraint system to a Matrix-form context such as x = x U y void merge_assign(PIP_Tree_Node::matrix_type& x,