Kokkos_Atomic.hpp

Go to the documentation of this file.

/*
//@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_ATOMIC_HPP
#define KOKKOS_ATOMIC_HPP

#include <Kokkos_Macros.hpp>
#include <impl/Kokkos_Traits.hpp>

//----------------------------------------------------------------------------

#if defined( __CUDA_ARCH__ )

// Compiling NVIDIA device code, must use Cuda atomics:

#define KOKKOS_ATOMICS_USE_CUDA

#elif ! defined( KOKKOS_ATOMICS_USE_GCC ) && \
      ! defined( KOKKOS_ATOMICS_USE_INTEL ) && \
      ! defined( KOKKOS_ATOMICS_USE_OMP31 )

// Compiling for non-Cuda atomic implementation has not been pre-selected.
// Choose the best implementation for the detected compiler.
// Preference: GCC, INTEL, OMP31

#if defined( KOKKOS_COMPILER_GNU ) || \
    defined( KOKKOS_COMPILER_CLANG )

#define KOKKOS_ATOMICS_USE_GCC

#elif defined( KOKKOS_COMPILER_INTEL ) || \
      defined( KOKKOS_COMPILER_CRAYC )

#define KOKKOS_ATOMICS_USE_INTEL

#elif defined( _OPENMP ) && ( 201107 <= _OPENMP )

#define KOKKOS_ATOMICS_USE_OMP31

#else

#error "KOKKOS_ATOMICS_USE : Unsupported compiler"

#endif

#endif /* Not pre-selected atomic implementation */

//----------------------------------------------------------------------------

namespace Kokkos {


inline
const char * atomic_query_version()
{
#if defined( KOKKOS_ATOMICS_USE_CUDA )
  return "KOKKOS_ATOMICS_USE_CUDA" ;
#elif defined( KOKKOS_ATOMICS_USE_GCC )
  return "KOKKOS_ATOMICS_USE_GCC" ;
#elif defined( KOKKOS_ATOMICS_USE_INTEL )
  return "KOKKOS_ATOMICS_USE_INTEL" ;
#elif defined( KOKKOS_ATOMICS_USE_OMP31 )
  return "KOKKOS_ATOMICS_USE_OMP31" ;
#endif
}

} // namespace Kokkos

//----------------------------------------------------------------------------
// Atomic exchange
//
// template< typename T >
// T atomic_exchange( volatile T* const dest , const T val )
// { T tmp = *dest ; *dest = val ; return tmp ; }

#include "impl/Kokkos_Atomic_Exchange.hpp"

//----------------------------------------------------------------------------
// Atomic compare-and-exchange
//
// template<class T>
// bool atomic_compare_exchange_strong(volatile T* const dest, const T compare, const T val)
// { bool equal = compare == *dest ; if ( equal ) { *dest = val ; } return equal ; }

#include "impl/Kokkos_Atomic_Compare_Exchange_Strong.hpp"

//----------------------------------------------------------------------------
// Atomic fetch and add
//
// template<class T>
// T atomic_fetch_add(volatile T* const dest, const T val)
// { T tmp = *dest ; *dest += val ; return tmp ; }

#include "impl/Kokkos_Atomic_Fetch_Add.hpp"

//----------------------------------------------------------------------------
// Atomic fetch and or
//
// template<class T>
// T atomic_fetch_or(volatile T* const dest, const T val)
// { T tmp = *dest ; *dest = tmp | val ; return tmp ; }

#include "impl/Kokkos_Atomic_Fetch_Or.hpp"

//----------------------------------------------------------------------------
// Atomic fetch and and
//
// template<class T>
// T atomic_fetch_and(volatile T* const dest, const T val)
// { T tmp = *dest ; *dest = tmp & val ; return tmp ; }

#include "impl/Kokkos_Atomic_Fetch_And.hpp"

//----------------------------------------------------------------------------
// Memory fence
//
// All loads and stores from this thread will be globally consistent before continuing
//
// void memory_fence() {...};
#include "impl/Kokkos_Memory_Fence.hpp"

//----------------------------------------------------------------------------
// Provide volatile_load and safe_load
//
// T volatile_load(T const volatile * const ptr);
//
// T const& safe_load(T const * const ptr);
// XEON PHI
// T safe_load(T const * const ptr

#include "impl/Kokkos_Volatile_Load.hpp"

#include "impl/Kokkos_Atomic_Generic.hpp"

//----------------------------------------------------------------------------
// This atomic-style macro should be an inlined function, not a macro

#if defined( KOKKOS_COMPILER_GNU )

  #define KOKKOS_NONTEMPORAL_PREFETCH_LOAD(addr) __builtin_prefetch(addr,0,0)
  #define KOKKOS_NONTEMPORAL_PREFETCH_STORE(addr) __builtin_prefetch(addr,1,0)

#else

  #define KOKKOS_NONTEMPORAL_PREFETCH_LOAD(addr) ((void)0)
  #define KOKKOS_NONTEMPORAL_PREFETCH_STORE(addr) ((void)0)

#endif

//----------------------------------------------------------------------------

#endif /* KOKKOS_ATOMIC_HPP */