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Posted to commits@mahout.apache.org by ap...@apache.org on 2016/06/10 16:52:26 UTC

[21/51] [partial] mahout git commit: Revert "(nojira) add native-viennaCL module to codebase. closes apache/mahout#241"

http://git-wip-us.apache.org/repos/asf/mahout/blob/7ae549fa/native-viennaCL/src/main/cpp/viennacl/linalg/host_based/iterative_operations.hpp
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diff --git a/native-viennaCL/src/main/cpp/viennacl/linalg/host_based/iterative_operations.hpp b/native-viennaCL/src/main/cpp/viennacl/linalg/host_based/iterative_operations.hpp
deleted file mode 100644
index ee6626c..0000000
--- a/native-viennaCL/src/main/cpp/viennacl/linalg/host_based/iterative_operations.hpp
+++ /dev/null
@@ -1,880 +0,0 @@
-#ifndef VIENNACL_LINALG_HOST_BASED_ITERATIVE_OPERATIONS_HPP_
-#define VIENNACL_LINALG_HOST_BASED_ITERATIVE_OPERATIONS_HPP_
-
-/* =========================================================================
-   Copyright (c) 2010-2016, Institute for Microelectronics,
-                            Institute for Analysis and Scientific Computing,
-                            TU Wien.
-   Portions of this software are copyright by UChicago Argonne, LLC.
-
-                            -----------------
-                  ViennaCL - The Vienna Computing Library
-                            -----------------
-
-   Project Head:    Karl Rupp                   rupp@iue.tuwien.ac.at
-
-   (A list of authors and contributors can be found in the manual)
-
-   License:         MIT (X11), see file LICENSE in the base directory
-============================================================================= */
-
-/** @file viennacl/linalg/host_based/iterative_operations.hpp
-    @brief Implementations of specialized kernels for fast iterative solvers using OpenMP on the CPU
-*/
-
-#include <cmath>
-#include <algorithm>  //for std::max and std::min
-
-#include "viennacl/forwards.h"
-#include "viennacl/scalar.hpp"
-#include "viennacl/tools/tools.hpp"
-#include "viennacl/meta/predicate.hpp"
-#include "viennacl/meta/enable_if.hpp"
-#include "viennacl/traits/size.hpp"
-#include "viennacl/traits/start.hpp"
-#include "viennacl/linalg/host_based/common.hpp"
-#include "viennacl/linalg/detail/op_applier.hpp"
-#include "viennacl/traits/stride.hpp"
-
-
-// Minimum vector size for using OpenMP on vector operations:
-#ifndef VIENNACL_OPENMP_VECTOR_MIN_SIZE
-  #define VIENNACL_OPENMP_VECTOR_MIN_SIZE  5000
-#endif
-
-namespace viennacl
-{
-namespace linalg
-{
-namespace host_based
-{
-
-namespace detail
-{
-  /** @brief Implementation of a fused matrix-vector product with a compressed_matrix for an efficient pipelined CG algorithm.
-    *
-    * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-    *   Ap = prod(A, p);
-    * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-    */
-  template<typename NumericT>
-  void pipelined_prod_impl(compressed_matrix<NumericT> const & A,
-                           vector_base<NumericT> const & p,
-                           vector_base<NumericT> & Ap,
-                           NumericT const * r0star,
-                           vector_base<NumericT> & inner_prod_buffer,
-                           vcl_size_t buffer_chunk_size,
-                           vcl_size_t buffer_chunk_offset)
-  {
-    typedef NumericT        value_type;
-
-    value_type         * Ap_buf      = detail::extract_raw_pointer<value_type>(Ap.handle()) + viennacl::traits::start(Ap);
-    value_type   const *  p_buf      = detail::extract_raw_pointer<value_type>(p.handle()) + viennacl::traits::start(p);
-    value_type   const * elements    = detail::extract_raw_pointer<value_type>(A.handle());
-    unsigned int const *  row_buffer = detail::extract_raw_pointer<unsigned int>(A.handle1());
-    unsigned int const *  col_buffer = detail::extract_raw_pointer<unsigned int>(A.handle2());
-    value_type         * data_buffer = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-    value_type inner_prod_ApAp = 0;
-    value_type inner_prod_pAp = 0;
-    value_type inner_prod_Ap_r0star = 0;
-    for (long row = 0; row < static_cast<long>(A.size1()); ++row)
-    {
-      value_type dot_prod = 0;
-      value_type val_p_diag = p_buf[static_cast<vcl_size_t>(row)]; //likely to be loaded from cache if required again in this row
-
-      vcl_size_t row_end = row_buffer[row+1];
-      for (vcl_size_t i = row_buffer[row]; i < row_end; ++i)
-        dot_prod += elements[i] * p_buf[col_buffer[i]];
-
-      // update contributions for the inner products (Ap, Ap) and (p, Ap)
-      Ap_buf[static_cast<vcl_size_t>(row)] = dot_prod;
-      inner_prod_ApAp += dot_prod * dot_prod;
-      inner_prod_pAp  += val_p_diag * dot_prod;
-      inner_prod_Ap_r0star += r0star ? dot_prod * r0star[static_cast<vcl_size_t>(row)] : value_type(0);
-    }
-
-    data_buffer[    buffer_chunk_size] = inner_prod_ApAp;
-    data_buffer[2 * buffer_chunk_size] = inner_prod_pAp;
-    if (r0star)
-      data_buffer[buffer_chunk_offset] = inner_prod_Ap_r0star;
-  }
-
-
-
-  /** @brief Implementation of a fused matrix-vector product with a coordinate_matrix for an efficient pipelined CG algorithm.
-    *
-    * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-    *   Ap = prod(A, p);
-    * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-    */
-  template<typename NumericT>
-  void pipelined_prod_impl(coordinate_matrix<NumericT> const & A,
-                           vector_base<NumericT> const & p,
-                           vector_base<NumericT> & Ap,
-                           NumericT const * r0star,
-                           vector_base<NumericT> & inner_prod_buffer,
-                           vcl_size_t buffer_chunk_size,
-                           vcl_size_t buffer_chunk_offset)
-  {
-    typedef NumericT        value_type;
-
-    value_type         * Ap_buf       = detail::extract_raw_pointer<value_type>(Ap.handle()) + viennacl::traits::start(Ap);;
-    value_type   const *  p_buf       = detail::extract_raw_pointer<value_type>(p.handle()) + viennacl::traits::start(p);;
-    value_type   const * elements     = detail::extract_raw_pointer<value_type>(A.handle());
-    unsigned int const * coord_buffer = detail::extract_raw_pointer<unsigned int>(A.handle12());
-    value_type         * data_buffer  = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-    // flush result buffer (cannot be expected to be zero)
-    for (vcl_size_t i = 0; i< Ap.size(); ++i)
-      Ap_buf[i] = 0;
-
-    // matrix-vector product with a general COO format
-    for (vcl_size_t i = 0; i < A.nnz(); ++i)
-      Ap_buf[coord_buffer[2*i]] += elements[i] * p_buf[coord_buffer[2*i+1]];
-
-    // computing the inner products (Ap, Ap) and (p, Ap):
-    // Note: The COO format does not allow to inject the subsequent operations into the matrix-vector product, because row and column ordering assumptions are too weak
-    value_type inner_prod_ApAp = 0;
-    value_type inner_prod_pAp = 0;
-    value_type inner_prod_Ap_r0star = 0;
-    for (vcl_size_t i = 0; i<Ap.size(); ++i)
-    {
-      NumericT value_Ap = Ap_buf[i];
-      NumericT value_p  =  p_buf[i];
-
-      inner_prod_ApAp += value_Ap * value_Ap;
-      inner_prod_pAp  += value_Ap * value_p;
-      inner_prod_Ap_r0star += r0star ? value_Ap * r0star[i] : value_type(0);
-    }
-
-    data_buffer[    buffer_chunk_size] = inner_prod_ApAp;
-    data_buffer[2 * buffer_chunk_size] = inner_prod_pAp;
-    if (r0star)
-      data_buffer[buffer_chunk_offset] = inner_prod_Ap_r0star;
-  }
-
-
-  /** @brief Implementation of a fused matrix-vector product with an ell_matrix for an efficient pipelined CG algorithm.
-    *
-    * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-    *   Ap = prod(A, p);
-    * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-    */
-  template<typename NumericT>
-  void pipelined_prod_impl(ell_matrix<NumericT> const & A,
-                           vector_base<NumericT> const & p,
-                           vector_base<NumericT> & Ap,
-                           NumericT const * r0star,
-                           vector_base<NumericT> & inner_prod_buffer,
-                           vcl_size_t buffer_chunk_size,
-                           vcl_size_t buffer_chunk_offset)
-  {
-    typedef NumericT     value_type;
-
-    value_type         * Ap_buf       = detail::extract_raw_pointer<value_type>(Ap.handle()) + viennacl::traits::start(Ap);;
-    value_type   const *  p_buf       = detail::extract_raw_pointer<value_type>(p.handle()) + viennacl::traits::start(p);;
-    value_type   const * elements     = detail::extract_raw_pointer<value_type>(A.handle());
-    unsigned int const * coords       = detail::extract_raw_pointer<unsigned int>(A.handle2());
-    value_type         * data_buffer  = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-    value_type inner_prod_ApAp = 0;
-    value_type inner_prod_pAp = 0;
-    value_type inner_prod_Ap_r0star = 0;
-    for (vcl_size_t row = 0; row < A.size1(); ++row)
-    {
-      value_type sum = 0;
-      value_type val_p_diag = p_buf[static_cast<vcl_size_t>(row)]; //likely to be loaded from cache if required again in this row
-
-      for (unsigned int item_id = 0; item_id < A.internal_maxnnz(); ++item_id)
-      {
-        vcl_size_t offset = row + item_id * A.internal_size1();
-        value_type val = elements[offset];
-
-        if (val)
-          sum += (p_buf[coords[offset]] * val);
-      }
-
-      Ap_buf[row] = sum;
-      inner_prod_ApAp += sum * sum;
-      inner_prod_pAp  += val_p_diag * sum;
-      inner_prod_Ap_r0star += r0star ? sum * r0star[row] : value_type(0);
-    }
-
-    data_buffer[    buffer_chunk_size] = inner_prod_ApAp;
-    data_buffer[2 * buffer_chunk_size] = inner_prod_pAp;
-    if (r0star)
-      data_buffer[buffer_chunk_offset] = inner_prod_Ap_r0star;
-  }
-
-
-  /** @brief Implementation of a fused matrix-vector product with an sliced_ell_matrix for an efficient pipelined CG algorithm.
-    *
-    * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-    *   Ap = prod(A, p);
-    * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-    */
-  template<typename NumericT, typename IndexT>
-  void pipelined_prod_impl(sliced_ell_matrix<NumericT, IndexT> const & A,
-                           vector_base<NumericT> const & p,
-                           vector_base<NumericT> & Ap,
-                           NumericT const * r0star,
-                           vector_base<NumericT> & inner_prod_buffer,
-                           vcl_size_t buffer_chunk_size,
-                           vcl_size_t buffer_chunk_offset)
-  {
-    typedef NumericT     value_type;
-
-    value_type       * Ap_buf            = detail::extract_raw_pointer<value_type>(Ap.handle()) + viennacl::traits::start(Ap);;
-    value_type const *  p_buf            = detail::extract_raw_pointer<value_type>(p.handle()) + viennacl::traits::start(p);;
-    value_type const * elements          = detail::extract_raw_pointer<value_type>(A.handle());
-    IndexT     const * columns_per_block = detail::extract_raw_pointer<IndexT>(A.handle1());
-    IndexT     const * column_indices    = detail::extract_raw_pointer<IndexT>(A.handle2());
-    IndexT     const * block_start       = detail::extract_raw_pointer<IndexT>(A.handle3());
-    value_type         * data_buffer     = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-    vcl_size_t num_blocks = A.size1() / A.rows_per_block() + 1;
-    std::vector<value_type> result_values(A.rows_per_block());
-
-    value_type inner_prod_ApAp = 0;
-    value_type inner_prod_pAp = 0;
-    value_type inner_prod_Ap_r0star = 0;
-    for (vcl_size_t block_idx = 0; block_idx < num_blocks; ++block_idx)
-    {
-      vcl_size_t current_columns_per_block = columns_per_block[block_idx];
-
-      for (vcl_size_t i=0; i<result_values.size(); ++i)
-        result_values[i] = 0;
-
-      for (IndexT column_entry_index = 0;
-                  column_entry_index < current_columns_per_block;
-                ++column_entry_index)
-      {
-        vcl_size_t stride_start = block_start[block_idx] + column_entry_index * A.rows_per_block();
-        // Note: This for-loop may be unrolled by hand for exploiting vectorization
-        //       Careful benchmarking recommended first, memory channels may be saturated already!
-        for (IndexT row_in_block = 0; row_in_block < A.rows_per_block(); ++row_in_block)
-        {
-          value_type val = elements[stride_start + row_in_block];
-
-          result_values[row_in_block] += val ? p_buf[column_indices[stride_start + row_in_block]] * val : 0;
-        }
-      }
-
-      vcl_size_t first_row_in_matrix = block_idx * A.rows_per_block();
-      for (IndexT row_in_block = 0; row_in_block < A.rows_per_block(); ++row_in_block)
-      {
-        vcl_size_t row = first_row_in_matrix + row_in_block;
-        if (row < Ap.size())
-        {
-          value_type row_result = result_values[row_in_block];
-
-          Ap_buf[row] = row_result;
-          inner_prod_ApAp += row_result * row_result;
-          inner_prod_pAp  += p_buf[row] * row_result;
-          inner_prod_Ap_r0star += r0star ? row_result * r0star[row] : value_type(0);
-        }
-      }
-    }
-
-    data_buffer[    buffer_chunk_size] = inner_prod_ApAp;
-    data_buffer[2 * buffer_chunk_size] = inner_prod_pAp;
-    if (r0star)
-      data_buffer[buffer_chunk_offset] = inner_prod_Ap_r0star;
-  }
-
-
-  /** @brief Implementation of a fused matrix-vector product with an hyb_matrix for an efficient pipelined CG algorithm.
-    *
-    * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-    *   Ap = prod(A, p);
-    * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-    */
-  template<typename NumericT>
-  void pipelined_prod_impl(hyb_matrix<NumericT> const & A,
-                           vector_base<NumericT> const & p,
-                           vector_base<NumericT> & Ap,
-                           NumericT const * r0star,
-                           vector_base<NumericT> & inner_prod_buffer,
-                           vcl_size_t buffer_chunk_size,
-                           vcl_size_t buffer_chunk_offset)
-  {
-    typedef NumericT     value_type;
-    typedef unsigned int index_type;
-
-    value_type       * Ap_buf            = detail::extract_raw_pointer<value_type>(Ap.handle()) + viennacl::traits::start(Ap);;
-    value_type const *  p_buf            = detail::extract_raw_pointer<value_type>(p.handle()) + viennacl::traits::start(p);;
-    value_type const * elements          = detail::extract_raw_pointer<value_type>(A.handle());
-    index_type const * coords            = detail::extract_raw_pointer<index_type>(A.handle2());
-    value_type const * csr_elements      = detail::extract_raw_pointer<value_type>(A.handle5());
-    index_type const * csr_row_buffer    = detail::extract_raw_pointer<index_type>(A.handle3());
-    index_type const * csr_col_buffer    = detail::extract_raw_pointer<index_type>(A.handle4());
-    value_type         * data_buffer     = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-    value_type inner_prod_ApAp = 0;
-    value_type inner_prod_pAp = 0;
-    value_type inner_prod_Ap_r0star = 0;
-    for (vcl_size_t row = 0; row < A.size1(); ++row)
-    {
-      value_type val_p_diag = p_buf[static_cast<vcl_size_t>(row)]; //likely to be loaded from cache if required again in this row
-      value_type sum = 0;
-
-      //
-      // Part 1: Process ELL part
-      //
-      for (index_type item_id = 0; item_id < A.internal_ellnnz(); ++item_id)
-      {
-        vcl_size_t offset = row + item_id * A.internal_size1();
-        value_type val = elements[offset];
-
-        if (val)
-          sum += p_buf[coords[offset]] * val;
-      }
-
-      //
-      // Part 2: Process HYB part
-      //
-      vcl_size_t col_begin = csr_row_buffer[row];
-      vcl_size_t col_end   = csr_row_buffer[row + 1];
-
-      for (vcl_size_t item_id = col_begin; item_id < col_end; item_id++)
-        sum += p_buf[csr_col_buffer[item_id]] * csr_elements[item_id];
-
-      Ap_buf[row] = sum;
-      inner_prod_ApAp += sum * sum;
-      inner_prod_pAp  += val_p_diag * sum;
-      inner_prod_Ap_r0star += r0star ? sum * r0star[row] : value_type(0);
-    }
-
-    data_buffer[    buffer_chunk_size] = inner_prod_ApAp;
-    data_buffer[2 * buffer_chunk_size] = inner_prod_pAp;
-    if (r0star)
-      data_buffer[buffer_chunk_offset] = inner_prod_Ap_r0star;
-  }
-
-} // namespace detail
-
-
-/** @brief Performs a joint vector update operation needed for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for vectors 'result', 'p', 'r', 'Ap':
-  *   result += alpha * p;
-  *   r      -= alpha * Ap;
-  *   p       = r + beta * p;
-  * and runs the parallel reduction stage for computing inner_prod(r,r)
-  */
-template<typename NumericT>
-void pipelined_cg_vector_update(vector_base<NumericT> & result,
-                                NumericT alpha,
-                                vector_base<NumericT> & p,
-                                vector_base<NumericT> & r,
-                                vector_base<NumericT> const & Ap,
-                                NumericT beta,
-                                vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT       value_type;
-
-  value_type       * data_result = detail::extract_raw_pointer<value_type>(result);
-  value_type       * data_p      = detail::extract_raw_pointer<value_type>(p);
-  value_type       * data_r      = detail::extract_raw_pointer<value_type>(r);
-  value_type const * data_Ap     = detail::extract_raw_pointer<value_type>(Ap);
-  value_type       * data_buffer = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-  // Note: Due to the special setting in CG, there is no need to check for sizes and strides
-  vcl_size_t size  = viennacl::traits::size(result);
-
-  value_type inner_prod_r = 0;
-  for (long i = 0; i < static_cast<long>(size); ++i)
-  {
-    value_type value_p = data_p[static_cast<vcl_size_t>(i)];
-    value_type value_r = data_r[static_cast<vcl_size_t>(i)];
-
-
-    data_result[static_cast<vcl_size_t>(i)] += alpha * value_p;
-    value_r -= alpha * data_Ap[static_cast<vcl_size_t>(i)];
-    value_p  = value_r + beta * value_p;
-    inner_prod_r += value_r * value_r;
-
-    data_p[static_cast<vcl_size_t>(i)] = value_p;
-    data_r[static_cast<vcl_size_t>(i)] = value_r;
-  }
-
-  data_buffer[0] = inner_prod_r;
-}
-
-
-/** @brief Performs a fused matrix-vector product with a compressed_matrix for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for a matrix A and vectors 'p' and 'Ap':
-  *   Ap = prod(A, p);
-  * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap)
-  */
-template<typename NumericT>
-void pipelined_cg_prod(compressed_matrix<NumericT> const & A,
-                       vector_base<NumericT> const & p,
-                       vector_base<NumericT> & Ap,
-                       vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT const *    PtrType;
-  viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, PtrType(NULL), inner_prod_buffer, inner_prod_buffer.size() / 3, 0);
-}
-
-
-
-/** @brief Performs a fused matrix-vector product with a coordinate_matrix for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for a matrix A and vectors 'p' and 'Ap':
-  *   Ap = prod(A, p);
-  * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap)
-  */
-template<typename NumericT>
-void pipelined_cg_prod(coordinate_matrix<NumericT> const & A,
-                       vector_base<NumericT> const & p,
-                       vector_base<NumericT> & Ap,
-                       vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT const *    PtrType;
-  viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, PtrType(NULL), inner_prod_buffer, inner_prod_buffer.size() / 3, 0);
-}
-
-
-/** @brief Performs a fused matrix-vector product with an ell_matrix for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for a matrix A and vectors 'p' and 'Ap':
-  *   Ap = prod(A, p);
-  * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap)
-  */
-template<typename NumericT>
-void pipelined_cg_prod(ell_matrix<NumericT> const & A,
-                       vector_base<NumericT> const & p,
-                       vector_base<NumericT> & Ap,
-                       vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT const *    PtrType;
-  viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, PtrType(NULL), inner_prod_buffer, inner_prod_buffer.size() / 3, 0);
-}
-
-
-/** @brief Performs a fused matrix-vector product with an sliced_ell_matrix for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for a matrix A and vectors 'p' and 'Ap':
-  *   Ap = prod(A, p);
-  * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap)
-  */
-template<typename NumericT, typename IndexT>
-void pipelined_cg_prod(sliced_ell_matrix<NumericT, IndexT> const & A,
-                       vector_base<NumericT> const & p,
-                       vector_base<NumericT> & Ap,
-                       vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT const *    PtrType;
-  viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, PtrType(NULL), inner_prod_buffer, inner_prod_buffer.size() / 3, 0);
-}
-
-
-
-
-/** @brief Performs a fused matrix-vector product with an hyb_matrix for an efficient pipelined CG algorithm.
-  *
-  * This routines computes for a matrix A and vectors 'p' and 'Ap':
-  *   Ap = prod(A, p);
-  * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap)
-  */
-template<typename NumericT>
-void pipelined_cg_prod(hyb_matrix<NumericT> const & A,
-                       vector_base<NumericT> const & p,
-                       vector_base<NumericT> & Ap,
-                       vector_base<NumericT> & inner_prod_buffer)
-{
-  typedef NumericT const *    PtrType;
-  viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, PtrType(NULL), inner_prod_buffer, inner_prod_buffer.size() / 3, 0);
-}
-
-//////////////////////////
-
-
-/** @brief Performs a joint vector update operation needed for an efficient pipelined BiCGStab algorithm.
-  *
-  * This routines computes for vectors 's', 'r', 'Ap':
-  *   s = r - alpha * Ap
-  * with alpha obtained from a reduction step on the 0th and the 3rd out of 6 chunks in inner_prod_buffer
-  * and runs the parallel reduction stage for computing inner_prod(s,s)
-  */
-template<typename NumericT>
-void pipelined_bicgstab_update_s(vector_base<NumericT> & s,
-                                 vector_base<NumericT> & r,
-                                 vector_base<NumericT> const & Ap,
-                                 vector_base<NumericT> & inner_prod_buffer,
-                                 vcl_size_t buffer_chunk_size,
-                                 vcl_size_t buffer_chunk_offset)
-{
-  typedef NumericT      value_type;
-
-  value_type       * data_s      = detail::extract_raw_pointer<value_type>(s);
-  value_type       * data_r      = detail::extract_raw_pointer<value_type>(r);
-  value_type const * data_Ap     = detail::extract_raw_pointer<value_type>(Ap);
-  value_type       * data_buffer = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-  // Note: Due to the special setting in CG, there is no need to check for sizes and strides
-  vcl_size_t size  = viennacl::traits::size(s);
-
-  // part 1: compute alpha:
-  value_type r_in_r0 = 0;
-  value_type Ap_in_r0 = 0;
-  for (vcl_size_t i=0; i<buffer_chunk_size; ++i)
-  {
-     r_in_r0 += data_buffer[i];
-    Ap_in_r0 += data_buffer[i + 3 * buffer_chunk_size];
-  }
-  value_type alpha = r_in_r0 / Ap_in_r0;
-
-  // part 2: s = r - alpha * Ap  and first step in reduction for s:
-  value_type inner_prod_s = 0;
-  for (long i = 0; i < static_cast<long>(size); ++i)
-  {
-    value_type value_s  = data_s[static_cast<vcl_size_t>(i)];
-
-    value_s = data_r[static_cast<vcl_size_t>(i)] - alpha * data_Ap[static_cast<vcl_size_t>(i)];
-    inner_prod_s += value_s * value_s;
-
-    data_s[static_cast<vcl_size_t>(i)] = value_s;
-  }
-
-  data_buffer[buffer_chunk_offset] = inner_prod_s;
-}
-
-/** @brief Performs a joint vector update operation needed for an efficient pipelined BiCGStab algorithm.
-  *
-  * x_{j+1} = x_j + alpha * p_j + omega * s_j
-  * r_{j+1} = s_j - omega * t_j
-  * p_{j+1} = r_{j+1} + beta * (p_j - omega * q_j)
-  * and compute first stage of r_dot_r0 = <r_{j+1}, r_o^*> for use in next iteration
-  */
- template<typename NumericT>
- void pipelined_bicgstab_vector_update(vector_base<NumericT> & result, NumericT alpha, vector_base<NumericT> & p, NumericT omega, vector_base<NumericT> const & s,
-                                       vector_base<NumericT> & residual, vector_base<NumericT> const & As,
-                                       NumericT beta, vector_base<NumericT> const & Ap,
-                                       vector_base<NumericT> const & r0star,
-                                       vector_base<NumericT>       & inner_prod_buffer,
-                                       vcl_size_t buffer_chunk_size)
- {
-   typedef NumericT    value_type;
-
-   value_type       * data_result   = detail::extract_raw_pointer<value_type>(result);
-   value_type       * data_p        = detail::extract_raw_pointer<value_type>(p);
-   value_type const * data_s        = detail::extract_raw_pointer<value_type>(s);
-   value_type       * data_residual = detail::extract_raw_pointer<value_type>(residual);
-   value_type const * data_As       = detail::extract_raw_pointer<value_type>(As);
-   value_type const * data_Ap       = detail::extract_raw_pointer<value_type>(Ap);
-   value_type const * data_r0star   = detail::extract_raw_pointer<value_type>(r0star);
-   value_type       * data_buffer   = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-
-   vcl_size_t size = viennacl::traits::size(result);
-
-   value_type inner_prod_r_r0star = 0;
-   for (long i = 0; i < static_cast<long>(size); ++i)
-   {
-     vcl_size_t index = static_cast<vcl_size_t>(i);
-     value_type value_result   = data_result[index];
-     value_type value_p        = data_p[index];
-     value_type value_s        = data_s[index];
-     value_type value_residual = data_residual[index];
-     value_type value_As       = data_As[index];
-     value_type value_Ap       = data_Ap[index];
-     value_type value_r0star   = data_r0star[index];
-
-     value_result   += alpha * value_p + omega * value_s;
-     value_residual  = value_s - omega * value_As;
-     value_p         = value_residual + beta * (value_p - omega * value_Ap);
-     inner_prod_r_r0star += value_residual * value_r0star;
-
-     data_result[index]   = value_result;
-     data_residual[index] = value_residual;
-     data_p[index]        = value_p;
-   }
-
-   (void)buffer_chunk_size; // not needed here, just silence compiler warning (unused variable)
-   data_buffer[0] = inner_prod_r_r0star;
- }
-
- /** @brief Performs a fused matrix-vector product with a compressed_matrix for an efficient pipelined BiCGStab algorithm.
-   *
-   * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-   *   Ap = prod(A, p);
-   * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-   */
- template<typename NumericT>
- void pipelined_bicgstab_prod(compressed_matrix<NumericT> const & A,
-                              vector_base<NumericT> const & p,
-                              vector_base<NumericT> & Ap,
-                              vector_base<NumericT> const & r0star,
-                              vector_base<NumericT> & inner_prod_buffer,
-                              vcl_size_t buffer_chunk_size,
-                              vcl_size_t buffer_chunk_offset)
- {
-   NumericT const * data_r0star   = detail::extract_raw_pointer<NumericT>(r0star);
-
-   viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, data_r0star, inner_prod_buffer, buffer_chunk_size, buffer_chunk_offset);
- }
-
- /** @brief Performs a fused matrix-vector product with a coordinate_matrix for an efficient pipelined BiCGStab algorithm.
-   *
-   * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-   *   Ap = prod(A, p);
-   * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-   */
- template<typename NumericT>
- void pipelined_bicgstab_prod(coordinate_matrix<NumericT> const & A,
-                              vector_base<NumericT> const & p,
-                              vector_base<NumericT> & Ap,
-                              vector_base<NumericT> const & r0star,
-                              vector_base<NumericT> & inner_prod_buffer,
-                              vcl_size_t buffer_chunk_size,
-                              vcl_size_t buffer_chunk_offset)
- {
-   NumericT const * data_r0star   = detail::extract_raw_pointer<NumericT>(r0star);
-
-   viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, data_r0star, inner_prod_buffer, buffer_chunk_size, buffer_chunk_offset);
- }
-
- /** @brief Performs a fused matrix-vector product with an ell_matrix for an efficient pipelined BiCGStab algorithm.
-   *
-   * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-   *   Ap = prod(A, p);
-   * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-   */
- template<typename NumericT>
- void pipelined_bicgstab_prod(ell_matrix<NumericT> const & A,
-                              vector_base<NumericT> const & p,
-                              vector_base<NumericT> & Ap,
-                              vector_base<NumericT> const & r0star,
-                              vector_base<NumericT> & inner_prod_buffer,
-                              vcl_size_t buffer_chunk_size,
-                              vcl_size_t buffer_chunk_offset)
- {
-   NumericT const * data_r0star   = detail::extract_raw_pointer<NumericT>(r0star);
-
-   viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, data_r0star, inner_prod_buffer, buffer_chunk_size, buffer_chunk_offset);
- }
-
- /** @brief Performs a fused matrix-vector product with a sliced_ell_matrix for an efficient pipelined BiCGStab algorithm.
-   *
-   * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-   *   Ap = prod(A, p);
-   * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-   */
- template<typename NumericT, typename IndexT>
- void pipelined_bicgstab_prod(sliced_ell_matrix<NumericT, IndexT> const & A,
-                              vector_base<NumericT> const & p,
-                              vector_base<NumericT> & Ap,
-                              vector_base<NumericT> const & r0star,
-                              vector_base<NumericT> & inner_prod_buffer,
-                              vcl_size_t buffer_chunk_size,
-                              vcl_size_t buffer_chunk_offset)
- {
-   NumericT const * data_r0star   = detail::extract_raw_pointer<NumericT>(r0star);
-
-   viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, data_r0star, inner_prod_buffer, buffer_chunk_size, buffer_chunk_offset);
- }
-
- /** @brief Performs a fused matrix-vector product with a hyb_matrix for an efficient pipelined BiCGStab algorithm.
-   *
-   * This routines computes for a matrix A and vectors 'p', 'Ap', and 'r0':
-   *   Ap = prod(A, p);
-   * and computes the two reduction stages for computing inner_prod(p,Ap), inner_prod(Ap,Ap), inner_prod(Ap, r0)
-   */
- template<typename NumericT>
- void pipelined_bicgstab_prod(hyb_matrix<NumericT> const & A,
-                              vector_base<NumericT> const & p,
-                              vector_base<NumericT> & Ap,
-                              vector_base<NumericT> const & r0star,
-                              vector_base<NumericT> & inner_prod_buffer,
-                              vcl_size_t buffer_chunk_size,
-                              vcl_size_t buffer_chunk_offset)
- {
-   NumericT const * data_r0star   = detail::extract_raw_pointer<NumericT>(r0star);
-
-   viennacl::linalg::host_based::detail::pipelined_prod_impl(A, p, Ap, data_r0star, inner_prod_buffer, buffer_chunk_size, buffer_chunk_offset);
- }
-
-
-/////////////////////////////////////////////////////////////
-
-/** @brief Performs a vector normalization needed for an efficient pipelined GMRES algorithm.
- *
- * This routines computes for vectors 'r', 'v_k':
- *   Second reduction step for ||v_k||
- *   v_k /= ||v_k||
- *   First reduction step for <r, v_k>
- */
-template <typename T>
-void pipelined_gmres_normalize_vk(vector_base<T> & v_k,
-                                 vector_base<T> const & residual,
-                                 vector_base<T> & R_buffer,
-                                 vcl_size_t offset_in_R,
-                                 vector_base<T> const & inner_prod_buffer,
-                                 vector_base<T> & r_dot_vk_buffer,
-                                 vcl_size_t buffer_chunk_size,
-                                 vcl_size_t buffer_chunk_offset)
-{
-  typedef T        value_type;
-
-  value_type       * data_v_k      = detail::extract_raw_pointer<value_type>(v_k);
-  value_type const * data_residual = detail::extract_raw_pointer<value_type>(residual);
-  value_type       * data_R        = detail::extract_raw_pointer<value_type>(R_buffer);
-  value_type const * data_buffer   = detail::extract_raw_pointer<value_type>(inner_prod_buffer);
-  value_type       * data_r_dot_vk = detail::extract_raw_pointer<value_type>(r_dot_vk_buffer);
-
-  // Note: Due to the special setting in GMRES, there is no need to check for sizes and strides
-  vcl_size_t size     = viennacl::traits::size(v_k);
-  vcl_size_t vk_start = viennacl::traits::start(v_k);
-
-  // part 1: compute alpha:
-  value_type norm_vk = 0;
-  for (vcl_size_t i=0; i<buffer_chunk_size; ++i)
-   norm_vk += data_buffer[i + buffer_chunk_size];
-  norm_vk = std::sqrt(norm_vk);
-  data_R[offset_in_R] = norm_vk;
-
-  // Compute <r, v_k> after normalization of v_k:
-  value_type inner_prod_r_dot_vk = 0;
-  for (long i = 0; i < static_cast<long>(size); ++i)
-  {
-    value_type value_vk = data_v_k[static_cast<vcl_size_t>(i) + vk_start] / norm_vk;
-
-    inner_prod_r_dot_vk += data_residual[static_cast<vcl_size_t>(i)] * value_vk;
-
-    data_v_k[static_cast<vcl_size_t>(i) + vk_start] = value_vk;
-  }
-
-  data_r_dot_vk[buffer_chunk_offset] = inner_prod_r_dot_vk;
-}
-
-
-
-/** @brief Computes first reduction stage for multiple inner products <v_i, v_k>, i=0..k-1
- *
- *  All vectors v_i are stored column-major in the array 'device_krylov_basis', where each vector has an actual length 'v_k_size', but might be padded to have 'v_k_internal_size'
- */
-template <typename T>
-void pipelined_gmres_gram_schmidt_stage1(vector_base<T> const & device_krylov_basis,
-                                        vcl_size_t v_k_size,
-                                        vcl_size_t v_k_internal_size,
-                                        vcl_size_t k,
-                                        vector_base<T> & vi_in_vk_buffer,
-                                        vcl_size_t buffer_chunk_size)
-{
-  typedef T        value_type;
-
-  value_type const * data_krylov_basis = detail::extract_raw_pointer<value_type>(device_krylov_basis);
-  value_type       * data_inner_prod   = detail::extract_raw_pointer<value_type>(vi_in_vk_buffer);
-
-  // reset buffer:
-  for (vcl_size_t j = 0; j < k; ++j)
-    data_inner_prod[j*buffer_chunk_size] = value_type(0);
-
-  // compute inner products:
-  for (vcl_size_t i = 0; i < v_k_size; ++i)
-  {
-    value_type value_vk = data_krylov_basis[static_cast<vcl_size_t>(i) + k * v_k_internal_size];
-
-    for (vcl_size_t j = 0; j < k; ++j)
-      data_inner_prod[j*buffer_chunk_size] += data_krylov_basis[static_cast<vcl_size_t>(i) + j * v_k_internal_size] * value_vk;
-  }
-}
-
-
-/** @brief Computes the second reduction stage for multiple inner products <v_i, v_k>, i=0..k-1, then updates v_k -= <v_i, v_k> v_i and computes the first reduction stage for ||v_k||
- *
- *  All vectors v_i are stored column-major in the array 'device_krylov_basis', where each vector has an actual length 'v_k_size', but might be padded to have 'v_k_internal_size'
- */
-template <typename T>
-void pipelined_gmres_gram_schmidt_stage2(vector_base<T> & device_krylov_basis,
-                                        vcl_size_t v_k_size,
-                                        vcl_size_t v_k_internal_size,
-                                        vcl_size_t k,
-                                        vector_base<T> const & vi_in_vk_buffer,
-                                        vector_base<T> & R_buffer,
-                                        vcl_size_t krylov_dim,
-                                        vector_base<T> & inner_prod_buffer,
-                                        vcl_size_t buffer_chunk_size)
-{
-  typedef T        value_type;
-
-  value_type * data_krylov_basis = detail::extract_raw_pointer<value_type>(device_krylov_basis);
-
-  std::vector<T> values_vi_in_vk(k);
-
-  // Step 1: Finish reduction of <v_i, v_k> to obtain scalars:
-  for (std::size_t i=0; i<k; ++i)
-    for (vcl_size_t j=0; j<buffer_chunk_size; ++j)
-      values_vi_in_vk[i] += vi_in_vk_buffer[i*buffer_chunk_size + j];
-
-
-  // Step 2: Compute v_k -= <v_i, v_k> v_i and reduction on ||v_k||:
-  value_type norm_vk = 0;
-  for (vcl_size_t i = 0; i < v_k_size; ++i)
-  {
-    value_type value_vk = data_krylov_basis[static_cast<vcl_size_t>(i) + k * v_k_internal_size];
-
-    for (vcl_size_t j = 0; j < k; ++j)
-      value_vk -= values_vi_in_vk[j] * data_krylov_basis[static_cast<vcl_size_t>(i) + j * v_k_internal_size];
-
-    norm_vk += value_vk * value_vk;
-    data_krylov_basis[static_cast<vcl_size_t>(i) + k * v_k_internal_size] = value_vk;
-  }
-
-  // Step 3: Write values to R_buffer:
-  for (std::size_t i=0; i<k; ++i)
-    R_buffer[i + k * krylov_dim] = values_vi_in_vk[i];
-
-  inner_prod_buffer[buffer_chunk_size] = norm_vk;
-}
-
-/** @brief Computes x += eta_0 r + sum_{i=1}^{k-1} eta_i v_{i-1} */
-template <typename T>
-void pipelined_gmres_update_result(vector_base<T> & result,
-                                  vector_base<T> const & residual,
-                                  vector_base<T> const & krylov_basis,
-                                  vcl_size_t v_k_size,
-                                  vcl_size_t v_k_internal_size,
-                                  vector_base<T> const & coefficients,
-                                  vcl_size_t k)
-{
-  typedef T        value_type;
-
-  value_type       * data_result       = detail::extract_raw_pointer<value_type>(result);
-  value_type const * data_residual     = detail::extract_raw_pointer<value_type>(residual);
-  value_type const * data_krylov_basis = detail::extract_raw_pointer<value_type>(krylov_basis);
-  value_type const * data_coefficients = detail::extract_raw_pointer<value_type>(coefficients);
-
-  for (vcl_size_t i = 0; i < v_k_size; ++i)
-  {
-    value_type value_result = data_result[i];
-
-    value_result += data_coefficients[0] * data_residual[i];
-    for (vcl_size_t j = 1; j<k; ++j)
-      value_result += data_coefficients[j] * data_krylov_basis[i + (j-1) * v_k_internal_size];
-
-    data_result[i] = value_result;
-  }
-
-}
-
-// Reuse implementation from CG:
-template <typename MatrixType, typename T>
-void pipelined_gmres_prod(MatrixType const & A,
-                      vector_base<T> const & p,
-                      vector_base<T> & Ap,
-                      vector_base<T> & inner_prod_buffer)
-{
-  pipelined_cg_prod(A, p, Ap, inner_prod_buffer);
-}
-
-
-} //namespace host_based
-} //namespace linalg
-} //namespace viennacl
-
-
-#endif