Kokkos Core Kernels Package  Version of the Day
Kokkos_ScratchSpace.hpp
1 /*
2 //@HEADER
3 // ************************************************************************
4 //
5 // Kokkos v. 3.0
6 // Copyright (2020) National Technology & Engineering
7 // Solutions of Sandia, LLC (NTESS).
8 //
9 // Under the terms of Contract DE-NA0003525 with NTESS,
10 // the U.S. Government retains certain rights in this software.
11 //
12 // Redistribution and use in source and binary forms, with or without
13 // modification, are permitted provided that the following conditions are
14 // met:
15 //
16 // 1. Redistributions of source code must retain the above copyright
17 // notice, this list of conditions and the following disclaimer.
18 //
19 // 2. Redistributions in binary form must reproduce the above copyright
20 // notice, this list of conditions and the following disclaimer in the
21 // documentation and/or other materials provided with the distribution.
22 //
23 // 3. Neither the name of the Corporation nor the names of the
24 // contributors may be used to endorse or promote products derived from
25 // this software without specific prior written permission.
26 //
27 // THIS SOFTWARE IS PROVIDED BY NTESS "AS IS" AND ANY
28 // EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 // PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL NTESS OR THE
31 // CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32 // EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
33 // PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
34 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
35 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
36 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
37 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 //
39 // Questions? Contact Christian R. Trott (crtrott@sandia.gov)
40 //
41 // ************************************************************************
42 //@HEADER
43 */
44 
45 #ifndef KOKKOS_SCRATCHSPACE_HPP
46 #define KOKKOS_SCRATCHSPACE_HPP
47 
48 #include <cstdio>
49 #include <cstddef>
50 #include <Kokkos_Core_fwd.hpp>
51 #include <Kokkos_Concepts.hpp>
52 
53 /*--------------------------------------------------------------------------*/
54 
55 namespace Kokkos {
56 
60 template <class ExecSpace>
62  static_assert(
63  is_execution_space<ExecSpace>::value,
64  "Instantiating ScratchMemorySpace on non-execution-space type.");
65 
66  public:
67  // Alignment of memory chunks returned by 'get'
68  // must be a power of two
69  enum { ALIGN = 8 };
70 
71  private:
72  mutable char* m_iter_L0 = nullptr;
73  mutable char* m_iter_L1 = nullptr;
74  char* m_end_L0 = nullptr;
75  char* m_end_L1 = nullptr;
76 
77  mutable int m_multiplier = 0;
78  mutable int m_offset = 0;
79  mutable int m_default_level = 0;
80 
81  enum { MASK = ALIGN - 1 }; // Alignment used by View::shmem_size
82 
83  public:
86  using execution_space = ExecSpace;
88  using device_type = Kokkos::Device<execution_space, memory_space>;
89 
90  using array_layout = typename ExecSpace::array_layout;
91  using size_type = typename ExecSpace::size_type;
92 
93  static constexpr const char* name() { return "ScratchMemorySpace"; }
94 
95  template <typename IntType>
96  KOKKOS_INLINE_FUNCTION static IntType align(const IntType& size) {
97  return (size + MASK) & ~MASK;
98  }
99 
100  template <typename IntType>
101  KOKKOS_INLINE_FUNCTION void* get_shmem(const IntType& size,
102  int level = -1) const {
103  return get_shmem_common</*aligned*/ false>(size, 1, level);
104  }
105 
106  template <typename IntType>
107  KOKKOS_INLINE_FUNCTION void* get_shmem_aligned(const IntType& size,
108  const ptrdiff_t alignment,
109  int level = -1) const {
110  return get_shmem_common</*aligned*/ true>(size, alignment, level);
111  }
112 
113  private:
114  template <bool aligned, typename IntType>
115  KOKKOS_INLINE_FUNCTION void* get_shmem_common(const IntType& size,
116  const ptrdiff_t alignment,
117  int level = -1) const {
118  if (level == -1) level = m_default_level;
119  auto& m_iter = (level == 0) ? m_iter_L0 : m_iter_L1;
120  auto& m_end = (level == 0) ? m_end_L0 : m_end_L1;
121  char* previous = m_iter;
122  const ptrdiff_t missalign = size_t(m_iter) % alignment;
123  if (missalign) m_iter += alignment - missalign;
124 
125  void* tmp = m_iter + m_offset * (aligned ? size : align(size));
126  if (m_end < (m_iter += (aligned ? size : align(size)) * m_multiplier)) {
127  m_iter = previous; // put it back like it was
128 #ifdef KOKKOS_ENABLE_DEBUG
129  // mfh 23 Jun 2015: printf call consumes 25 registers
130  // in a CUDA build, so only print in debug mode. The
131  // function still returns nullptr if not enough memory.
132  KOKKOS_IMPL_DO_NOT_USE_PRINTF(
133  "ScratchMemorySpace<...>::get_shmem: Failed to allocate "
134  "%ld byte(s); remaining capacity is %ld byte(s)\n",
135  long(size), long(m_end - m_iter));
136 #endif // KOKKOS_ENABLE_DEBUG
137  tmp = nullptr;
138  }
139  return tmp;
140  }
141 
142  public:
143  KOKKOS_DEFAULTED_FUNCTION
144  ScratchMemorySpace() = default;
145 
146  template <typename IntType>
147  KOKKOS_INLINE_FUNCTION ScratchMemorySpace(void* ptr_L0,
148  const IntType& size_L0,
149  void* ptr_L1 = nullptr,
150  const IntType& size_L1 = 0)
151  : m_iter_L0((char*)ptr_L0),
152  m_iter_L1((char*)ptr_L1),
153  m_end_L0((char*)ptr_L0 + size_L0),
154  m_end_L1((char*)ptr_L1 + size_L1),
155  m_multiplier(1),
156  m_offset(0),
157  m_default_level(0) {}
158 
159  KOKKOS_INLINE_FUNCTION
160  const ScratchMemorySpace& set_team_thread_mode(const int& level,
161  const int& multiplier,
162  const int& offset) const {
163  m_default_level = level;
164  m_multiplier = multiplier;
165  m_offset = offset;
166  return *this;
167  }
168 };
169 
170 } // namespace Kokkos
171 
172 #endif /* #ifndef KOKKOS_SCRATCHSPACE_HPP */
Scratch memory space associated with an execution space.
Kokkos::Device< execution_space, memory_space > device_type
This execution space preferred device_type.
Definition: dummy.cpp:3