blas2_matrix_rank_1_update.hpp

/*
//@HEADER
// ************************************************************************
//
//                        Kokkos v. 2.0
//              Copyright (2019) Sandia Corporation
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software. //
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact Christian R. Trott (crtrott@sandia.gov)
//
// ************************************************************************
//@HEADER
*/

#ifndef LINALG_INCLUDE_EXPERIMENTAL___P1673_BITS_BLAS2_MATRIX_RANK_1_UPDATE_HPP_
#define LINALG_INCLUDE_EXPERIMENTAL___P1673_BITS_BLAS2_MATRIX_RANK_1_UPDATE_HPP_

namespace std {
namespace experimental {
inline namespace __p1673_version_0 {
namespace linalg {

namespace {

template <class Exec, class x_t, class y_t, class A_t, class = void>
struct is_custom_matrix_rank_1_update_avail : std::false_type {};

template <class Exec, class x_t, class y_t, class A_t>
struct is_custom_matrix_rank_1_update_avail<
  Exec, x_t, y_t, A_t,
  std::enable_if_t<
    std::is_void_v<
      decltype(matrix_rank_1_update
	       (std::declval<Exec>(),
		std::declval<x_t>(),
		std::declval<y_t>(),
		std::declval<A_t>()
		)
	       )
      >
    && !linalg::impl::is_inline_exec_v<Exec>
    >
  >
  : std::true_type{};

template <class Exec, class x_t, class A_t, class Tr_t, class = void>
struct is_custom_symmetric_matrix_rank_1_update_avail : std::false_type {};

template <class Exec, class x_t, class A_t, class Tr_t>
struct is_custom_symmetric_matrix_rank_1_update_avail<
  Exec, x_t, A_t, Tr_t,
  std::enable_if_t<
    std::is_void_v<
      decltype(symmetric_matrix_rank_1_update
	       (std::declval<Exec>(),
		std::declval<x_t>(),
		std::declval<A_t>(),
		std::declval<Tr_t>()
		)
	       )
      >
    && !linalg::impl::is_inline_exec_v<Exec>
    >
  >
  : std::true_type{};

template <class Exec, class x_t, class A_t, class Tr_t, class = void>
struct is_custom_hermitian_matrix_rank_1_update_avail : std::false_type {};

template <class Exec, class x_t, class A_t, class Tr_t>
struct is_custom_hermitian_matrix_rank_1_update_avail<
  Exec, x_t, A_t, Tr_t,
  std::enable_if_t<
    std::is_void_v<
      decltype(hermitian_matrix_rank_1_update
	       (std::declval<Exec>(),
		std::declval<x_t>(),
		std::declval<A_t>(),
		std::declval<Tr_t>()
		)
	       )
      >
    && !linalg::impl::is_inline_exec_v<Exec>
    >
  >
  : std::true_type{};

} // end anonymous namespace

// Nonsymmetric non-conjugated rank-1 update

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_y,
         extents<>::size_type ext_y,
         class Layout_y,
         class Accessor_y,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A>
void matrix_rank_1_update(
  std::experimental::linalg::impl::inline_exec_t&& /* exec */,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A)
{

  using size_type = typename extents<>::size_type;
  for (size_type i = 0; i < A.extent(0); ++i) {
    for (size_type j = 0; j < A.extent(1); ++j) {
      A(i,j) += x(i) * y(j);
    }
  }
}

template<class ExecutionPolicy,
         class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_y,
         extents<>::size_type ext_y,
         class Layout_y,
         class Accessor_y,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A>
void matrix_rank_1_update(
  ExecutionPolicy&& exec,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A)
{

  constexpr bool use_custom = is_custom_matrix_rank_1_update_avail<
    decltype(execpolicy_mapper(exec)), decltype(x), decltype(y), decltype(A)
    >::value;

  if constexpr(use_custom){
    matrix_rank_1_update(execpolicy_mapper(exec), x, y, A);
  }
  else
  {
    matrix_rank_1_update(std::experimental::linalg::impl::inline_exec_t(), x, y, A);
  }
}

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_y,
         extents<>::size_type ext_y,
         class Layout_y,
         class Accessor_y,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A>
void matrix_rank_1_update(
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A)
{
  matrix_rank_1_update(std::experimental::linalg::impl::default_exec_t(), x, y, A);
}


// Nonsymmetric conjugated rank-1 update

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_y,
         extents<>::size_type ext_y,
         class Layout_y,
         class Accessor_y,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A>
void matrix_rank_1_update_c(
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A)
{
  matrix_rank_1_update(x, conjugated(y), A);
}

template<class ExecutionPolicy,
         class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_y,
         extents<>::size_type ext_y,
         class Layout_y,
         class Accessor_y,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A>
void matrix_rank_1_update_c(
  ExecutionPolicy&& exec,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_y, std::experimental::extents<ext_y>, Layout_y, Accessor_y> y,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A)
{
  matrix_rank_1_update(exec, x, conjugated(y), A);
}

// Rank-1 update of a Symmetric matrix

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void symmetric_matrix_rank_1_update(
  std::experimental::linalg::impl::inline_exec_t&& /* exec */,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle /* t */)
{
  using size_type = typename extents<>::size_type;
  if constexpr (std::is_same_v<Triangle, lower_triangle_t>) {
    for (size_type j = 0; j < A.extent(1); ++j) {
      for (size_type i = j; i < A.extent(0); ++i) {
        A(i,j) += x(i) * x(j);
      }
    }
  }
  else {
    for (size_type j = 0; j < A.extent(1); ++j) {
      for (size_type i = 0; i <= j; ++i) {
        A(i,j) += x(i) * x(j);
      }
    }
  }
}

template<class ExecutionPolicy,
         class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void symmetric_matrix_rank_1_update(
  ExecutionPolicy&& exec,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle t)
{

  constexpr bool use_custom = is_custom_symmetric_matrix_rank_1_update_avail<
    decltype(execpolicy_mapper(exec)), decltype(x), decltype(A), Triangle
    >::value;

  if constexpr(use_custom){
    symmetric_matrix_rank_1_update(execpolicy_mapper(exec), x, A, t);
  }
  else
  {
    symmetric_matrix_rank_1_update(std::experimental::linalg::impl::inline_exec_t(), x, A, t);
  }
}

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void symmetric_matrix_rank_1_update(
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle t)
{
  symmetric_matrix_rank_1_update(std::experimental::linalg::impl::default_exec_t(), x, A, t);
}


// Rank-1 update of a Hermitian matrix

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void hermitian_matrix_rank_1_update(
  std::experimental::linalg::impl::inline_exec_t&& /* exec */,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle /* t */)
{
  using size_type = typename extents<>::size_type;

  if constexpr (std::is_same_v<Triangle, lower_triangle_t>) {
    for (size_type j = 0; j < A.extent(1); ++j) {
      for (size_type i = j; i < A.extent(0); ++i) {
        A(i,j) += x(i) * impl::conj_if_needed(x(j));
      }
    }
  }
  else {
    for (size_type j = 0; j < A.extent(1); ++j) {
      for (size_type i = 0; i <= j; ++i) {
        A(i,j) += x(i) * impl::conj_if_needed(x(j));
      }
    }
  }
}

template<class ExecutionPolicy,
         class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void hermitian_matrix_rank_1_update(
  ExecutionPolicy&& exec,
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle t)
{

  constexpr bool use_custom = is_custom_hermitian_matrix_rank_1_update_avail<
    decltype(execpolicy_mapper(exec)), decltype(x), decltype(A), Triangle
    >::value;

  if constexpr(use_custom){
    hermitian_matrix_rank_1_update(execpolicy_mapper(exec), x, A, t);
  }
  else
  {
    hermitian_matrix_rank_1_update(std::experimental::linalg::impl::inline_exec_t(), x, A, t);
  }
}

template<class ElementType_x,
         extents<>::size_type ext_x,
         class Layout_x,
         class Accessor_x,
         class ElementType_A,
         extents<>::size_type numRows_A,
         extents<>::size_type numCols_A,
         class Layout_A,
         class Accessor_A,
         class Triangle>
void hermitian_matrix_rank_1_update(
  std::experimental::mdspan<ElementType_x, std::experimental::extents<ext_x>, Layout_x, Accessor_x> x,
  std::experimental::mdspan<ElementType_A, std::experimental::extents<numRows_A, numCols_A>, Layout_A, Accessor_A> A,
  Triangle t)
{
  hermitian_matrix_rank_1_update(std::experimental::linalg::impl::default_exec_t(), x, A, t);
}

} // end namespace linalg
} // end inline namespace __p1673_version_0
} // end namespace experimental
} // end namespace std

#endif //LINALG_INCLUDE_EXPERIMENTAL___P1673_BITS_BLAS2_MATRIX_RANK_1_UPDATE_HPP_