git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@12370 f3b2605a-c512-4ea7-a41b-209d697bcdaa

lib/kokkos/containers/src/impl/Kokkos_Bitset_impl.hpp

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+/*
+//@HEADER
+// ************************************************************************
+//
+//   Kokkos: Manycore Performance-Portable Multidimensional Arrays
+//              Copyright (2012) 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  H. Carter Edwards (hcedwar@sandia.gov)
+//
+// ************************************************************************
+//@HEADER
+*/
+
+#ifndef KOKKOS_BITSET_IMPL_HPP
+#define KOKKOS_BITSET_IMPL_HPP
+
+#include <Kokkos_Macros.hpp>
+#include <stdint.h>
+
+#include <cstdio>
+#include <climits>
+#include <iostream>
+#include <iomanip>
+
+namespace Kokkos { namespace Impl {
+
+KOKKOS_FORCEINLINE_FUNCTION
+unsigned rotate_right(unsigned i, int r)
+{
+  enum { size = static_cast<int>(sizeof(unsigned)*CHAR_BIT) };
+  return r ? ((i >> r) | (i << (size-r))) : i ;
+}
+
+KOKKOS_FORCEINLINE_FUNCTION
+int bit_scan_forward(unsigned i)
+{
+#if defined( __CUDA_ARCH__ )
+  return __ffs(i) - 1;
+#elif defined( __GNUC__ ) || defined( __GNUG__ )
+  return __builtin_ffs(i) - 1;
+#elif defined( __INTEL_COMPILER )
+  return _bit_scan_forward(i);
+#else
+
+  unsigned t = 1u;
+  int r = 0;
+  while (i && (i & t == 0))
+  {
+    t = t << 1;
+    ++r;
+  }
+  return r;
+#endif
+}
+
+
+KOKKOS_FORCEINLINE_FUNCTION
+int bit_scan_reverse(unsigned i)
+{
+  enum { shift = static_cast<int>(sizeof(unsigned)*CHAR_BIT - 1) };
+#if defined( __CUDA_ARCH__ )
+  return shift - __clz(i);
+#elif defined( __GNUC__ ) || defined( __GNUG__ )
+  return shift - __builtin_clz(i);
+#elif defined( __INTEL_COMPILER )
+  return _bit_scan_reverse(i);
+#else
+  unsigned t = 1u << shift;
+  int r = 0;
+  while (i && (i & t == 0))
+  {
+    t = t >> 1;
+    ++r;
+  }
+  return r;
+#endif
+}
+
+
+// count the bits set
+KOKKOS_FORCEINLINE_FUNCTION
+int popcount(unsigned i)
+{
+#if defined( __CUDA_ARCH__ )
+  return __popc(i);
+#elif defined( __GNUC__ ) || defined( __GNUG__ )
+  return __builtin_popcount(i);
+#elif defined ( __INTEL_COMPILER )
+  return _popcnt32(i);
+#else
+  // http://graphics.stanford.edu/~seander/bithacks.html#CountBitsSetNaive
+  i = i - ((i >> 1) & ~0u/3u);                                         // temp
+  i = (i & ~0u/15u*3u) + ((i >> 2) & ~0u/15u*3u);                      // temp
+  i = (i + (i >> 4)) & ~0u/255u*15u;                                   // temp
+  return (int)((i * (~0u/255u)) >> (sizeof(unsigned) - 1) * CHAR_BIT); // count
+#endif
+}
+
+
+template <typename Bitset>
+struct BitsetCount
+{
+  typedef Bitset bitset_type;
+  typedef typename bitset_type::device_type device_type;
+  typedef typename bitset_type::size_type size_type;
+  typedef size_type value_type;
+
+  bitset_type m_bitset;
+
+  BitsetCount( bitset_type const& bitset)
+    : m_bitset(bitset)
+  {}
+
+  size_type apply() const
+  {
+    size_type count = 0u;
+    parallel_reduce(m_bitset.m_blocks.size(), *this, count);
+    return count;
+  }
+
+  KOKKOS_INLINE_FUNCTION
+  static void init( value_type & count)
+  {
+    count = 0u;
+  }
+
+  KOKKOS_INLINE_FUNCTION
+  static void join( volatile value_type & count, const volatile size_type & incr )
+  {
+    count += incr;
+  }
+
+  KOKKOS_INLINE_FUNCTION
+  void operator()( size_type i, value_type & count) const
+  {
+    count += popcount(m_bitset.m_blocks[i]);
+  }
+};
+
+}} //Kokkos::Impl
+
+#endif // KOKKOS_BITSET_IMPL_HPP
+