/usr/include/trilinos/impl/Kokkos_BitOps.hpp is in libtrilinos-kokkos-dev 12.12.1-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 | /*
//@HEADER
// ************************************************************************
//
// Kokkos v. 2.0
// Copyright (2014) 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_BITOPS_HPP
#define KOKKOS_BITOPS_HPP
#include <Kokkos_Macros.hpp>
#include <cstdint>
#include <climits>
namespace Kokkos {
namespace Impl {
/**\brief Find first zero bit.
*
* If none then return -1 ;
*/
KOKKOS_FORCEINLINE_FUNCTION
int bit_first_zero( unsigned i ) noexcept
{
enum : unsigned { full = ~0u };
#if defined( __CUDA_ARCH__ )
return full != i ? __ffs( ~i ) - 1 : -1 ;
#elif defined( KOKKOS_COMPILER_INTEL )
return full != i ? _bit_scan_forward( ~i ) : -1 ;
#elif defined( KOKKOS_COMPILER_IBM )
return full != i ? __cnttz4( ~i ) : -1 ;
#elif defined( KOKKOS_COMPILER_GNU ) || defined( __GNUC__ ) || defined( __GNUG__ )
return full != i ? __builtin_ffs( ~i ) - 1 : -1 ;
#else
int offset = -1 ;
if ( full != i ) {
for ( offset = 0 ; i & ( 1 << offset ) ; ++offset );
}
return offset ;
#endif
}
KOKKOS_FORCEINLINE_FUNCTION
int bit_scan_forward( unsigned i )
{
#if defined( __CUDA_ARCH__ )
return __ffs(i) - 1;
#elif defined( KOKKOS_COMPILER_INTEL )
return _bit_scan_forward(i);
#elif defined( KOKKOS_COMPILER_IBM )
return __cnttz4(i);
#elif defined( KOKKOS_COMPILER_GNU ) || defined( __GNUC__ ) || defined( __GNUG__ )
return __builtin_ffs(i) - 1;
#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( KOKKOS_COMPILER_INTEL )
return _bit_scan_reverse(i);
#elif defined( KOKKOS_COMPILER_IBM )
return shift - __cntlz4(i);
#elif defined( __GNUC__ ) || defined( __GNUG__ )
return shift - __builtin_clz(i);
#else
unsigned t = 1u << shift;
int r = 0;
while ( i && ( i & t == 0 ) )
{
t = t >> 1;
++r;
}
return r;
#endif
}
/// Count the number of bits set.
KOKKOS_FORCEINLINE_FUNCTION
int bit_count( unsigned i )
{
#if defined( __CUDA_ARCH__ )
return __popc(i);
#elif defined ( __INTEL_COMPILER )
return _popcnt32(i);
#elif defined( KOKKOS_COMPILER_IBM )
return __popcnt4(i);
#elif defined( __GNUC__ ) || defined( __GNUG__ )
return __builtin_popcount(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
// count
return (int)( ( i * ( ~0u / 255u ) ) >> ( sizeof(unsigned) - 1 ) * CHAR_BIT );
#endif
}
KOKKOS_INLINE_FUNCTION
unsigned integral_power_of_two_that_contains( const unsigned N )
{
const unsigned i = Kokkos::Impl::bit_scan_reverse( N );
return ( (1u << i) < N ) ? i + 1 : i ;
}
} // namespace Impl
} // namespace Kokkos
#endif // KOKKOS_BITOPS_HPP
|