C++ DistMatrix::LocalWidth方法代码示例

void L1DistanceMatrixTU(El::UpperOrLower uplo,
    direction_t dirA, direction_t dirB, T alpha,
    const El::DistMatrix<T, El::STAR, El::MC> &A,
    const El::DistMatrix<T, El::STAR, El::MR> &B,
    T beta, El::DistMatrix<T> &C) {

    // TODO verify sizes

    const T *a = A.LockedBuffer();
    El::Int ldA = A.LDim();

    const T *b = B.LockedBuffer();
    El::Int ldB = B.LDim();

    T *c = C.Buffer();
    El::Int ldC = C.LDim();

    El::Int d = A.Height();

    /* Not the most efficient way... but mimicking BLAS is too much work! */
    if (dirA == base::COLUMNS && dirB == base::COLUMNS) {
        El::Int n = C.LocalWidth();
        El::Int m = C.LocalHeight();
        for (El::Int j = 0; j < n; j++)
            for(El::Int i =
                    ((uplo == El::UPPER) ? 0 : C.LocalRowOffset(A.GlobalCol(j)));
                i < ((uplo == El::UPPER) ? C.LocalRowOffset(A.GlobalCol(j) + 1) : m); i++) {

                T v = 0.0;
                for (El::Int k = 0; k < d; k++)
                    v += std::abs(b[j * ldB + k] - a[i * ldA + k]);
                c[j * ldC + i] = beta * c[j * ldC + i] + alpha * v;
            }

    }

    // TODO the rest of the cases.
}

inline void outer_panel_mixed_gemm_impl_tn(
        const double alpha,
        const SpParMat<index_type, value_type, SpDCCols<index_type, value_type> > &A,
        const El::DistMatrix<value_type, col_d, El::STAR> &S,
        const double beta,
        El::DistMatrix<value_type, El::STAR, El::STAR> &C) {

    El::DistMatrix<value_type, El::STAR, El::STAR>
        tmp_C(C.Height(), C.Width());
    El::Zero(tmp_C);

    utility::combblas_slab_view_t<index_type, value_type> cbview(A, false);

    //FIXME: factor
    size_t slab_size = 2 * S.Grid().Height();
    for(size_t cur_row_idx = 0; cur_row_idx < cbview.ncols();
        cur_row_idx += slab_size) {

        size_t cur_slab_size =
            std::min(slab_size, cbview.ncols() - cur_row_idx);

        // get the next slab_size columns of B
        El::DistMatrix<value_type, El::STAR, El::STAR>
            A_row(cur_slab_size, S.Height());

        // transpose is column
        //cbview.extract_elemental_column_slab_view(A_row, cur_slab_size);
        cbview.extract_full_slab_view(cur_slab_size);

        // matrix mult (FIXME only iter nz)
        for(size_t l_row_idx = 0; l_row_idx < A_row.LocalHeight();
            ++l_row_idx) {

            size_t g_row_idx = l_row_idx * A_row.ColStride()
                               + A_row.ColShift() + cur_row_idx;

            for(size_t l_col_idx = 0; l_col_idx < A_row.LocalWidth();
                l_col_idx++) {

                //XXX: should be the same as l_col_idx
                size_t g_col_idx = l_col_idx * A_row.RowStride()
                                   + A_row.RowShift();

                // continue if we don't own values in S in this row
                if(!S.IsLocalRow(g_col_idx))
                    continue;

                //get transposed value
                value_type val = alpha * cbview(g_col_idx, g_row_idx);

                for(size_t s_col_idx = 0; s_col_idx < S.LocalWidth();
                    s_col_idx++) {

                    tmp_C.UpdateLocal(g_row_idx, s_col_idx,
                                val * S.GetLocal(S.LocalRow(g_col_idx), s_col_idx));
                }
            }
        }
    }

    //FIXME: scaling
    if(A.getcommgrid()->GetRank() == 0) {
        for(size_t col_idx = 0; col_idx < C.Width(); col_idx++)
            for(size_t row_idx = 0; row_idx < C.Height(); row_idx++)
                tmp_C.UpdateLocal(row_idx, col_idx,
                        beta * C.GetLocal(row_idx, col_idx));
    }

    //FIXME: Use utility getter
    boost::mpi::communicator world(
            A.getcommgrid()->GetWorld(), boost::mpi::comm_duplicate);
    boost::mpi::all_reduce (world,
                        tmp_C.LockedBuffer(),
                        C.Height() * C.Width(),
                        C.Buffer(),
                        std::plus<value_type>());
}