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In sparse matrix product, enable sorted insertion when doing two transposition is defenitely not optimal.

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This commit is contained in:
Gael Guennebaud 2014-08-29 11:55:03 +02:00
parent c3e4080474
commit 1ed9e2d004
1 changed files with 45 additions and 37 deletions
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82
Eigen/src/SparseCore/ConservativeSparseSparseProduct.h
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@ -15,7 +15,7 @@ namespace Eigen {
namespace internal {
template<typename Lhs, typename Rhs, typename ResultType>
static void conservative_sparse_sparse_product_impl(const Lhs& lhs, const Rhs& rhs, ResultType& res)
static void conservative_sparse_sparse_product_impl(const Lhs& lhs, const Rhs& rhs, ResultType& res, bool sortedInsertion = false)
{
typedef typename remove_all<Lhs>::type::Scalar Scalar;
typedef typename remove_all<Lhs>::type::Index Index;
@ -64,53 +64,51 @@ static void conservative_sparse_sparse_product_impl(const Lhs& lhs, const Rhs& r
values[i] += x * y;
}
}
// unordered insertion
for(Index k=0; k<nnz; ++k)
if(!sortedInsertion)
{
Index i = indices[k];
res.insertBackByOuterInnerUnordered(j,i) = values[i];
mask[i] = false;
}
#if 0
// alternative ordered insertion code:
Index t200 = rows/(log2(200)*1.39);
Index t = (rows*100)/139;
// FIXME reserve nnz non zeros
// FIXME implement fast sort algorithms for very small nnz
// if the result is sparse enough => use a quick sort
// otherwise => loop through the entire vector
// In order to avoid to perform an expensive log2 when the
// result is clearly very sparse we use a linear bound up to 200.
//if((nnz<200 && nnz<t200) || nnz * log2(nnz) < t)
//res.startVec(j);
if(true)
{
if(nnz>1) std::sort(indices.data(),indices.data()+nnz);
// unordered insertion
for(Index k=0; k<nnz; ++k)
{
Index i = indices[k];
res.insertBackByOuterInner(j,i) = values[i];
res.insertBackByOuterInnerUnordered(j,i) = values[i];
mask[i] = false;
}
}
else
{
// dense path
for(Index i=0; i<rows; ++i)
// alternative ordered insertion code:
const Index t200 = rows/(log2(200)*1.39);
const Index t = (rows*100)/139;
// FIXME reserve nnz non zeros
// FIXME implement faster sorting algorithms for very small nnz
// if the result is sparse enough => use a quick sort
// otherwise => loop through the entire vector
// In order to avoid to perform an expensive log2 when the
// result is clearly very sparse we use a linear bound up to 200.
if((nnz<200 && nnz<t200) || nnz * log2(nnz) < t)
{
if(mask[i])
if(nnz>1) std::sort(indices.data(),indices.data()+nnz);
for(Index k=0; k<nnz; ++k)
{
mask[i] = false;
Index i = indices[k];
res.insertBackByOuterInner(j,i) = values[i];
mask[i] = false;
}
}
else
{
// dense path
for(Index i=0; i<rows; ++i)
{
if(mask[i])
{
mask[i] = false;
res.insertBackByOuterInner(j,i) = values[i];
}
}
}
}
#endif
}
res.finalize();
}
@ -137,10 +135,20 @@ struct conservative_sparse_sparse_product_selector<Lhs,Rhs,ResultType,ColMajor,C
typedef SparseMatrix<typename ResultType::Scalar,RowMajor,typename ResultType::Index> RowMajorMatrix;
typedef SparseMatrix<typename ResultType::Scalar,ColMajor,typename ResultType::Index> ColMajorMatrix;
ColMajorMatrix resCol(lhs.rows(),rhs.cols());
internal::conservative_sparse_sparse_product_impl<Lhs,Rhs,ColMajorMatrix>(lhs, rhs, resCol);
// sort the non zeros:
RowMajorMatrix resRow(resCol);
res = resRow;
// FIXME, the following heuristic is probably not very good.
if(lhs.rows()>=rhs.cols())
{
// perform sorted insertion
internal::conservative_sparse_sparse_product_impl<Lhs,Rhs,ColMajorMatrix>(lhs, rhs, resCol, true);
res = resCol;
}
else
{
// ressort to transpose to sort the entries
internal::conservative_sparse_sparse_product_impl<Lhs,Rhs,ColMajorMatrix>(lhs, rhs, resCol, false);
RowMajorMatrix resRow(resCol);
res = resRow;
}
}
};