intel-qs/include/alignedallocator.hpp

147 lines
3.3 KiB
C++

// Copyright (C) 2012 Andreas Hehn <hehn@phys.ethz.ch>.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef IQS_ALIGNED_ALLOCATOR_HPP
#define IQS_ALIGNED_ALLOCATOR_HPP
/// \addtogroup sim
/// @{
/// @file alignedallocator.hpp
/// This header defines the class @c AlignedAllocator to provide aligned memory allocation
#include "bitops.hpp"
#ifdef _WIN32
#include <malloc.h>
#else
#include <cstdlib>
#endif
#include <cstddef>
#include <memory>
#include <new>
#if __cplusplus < 201103L
#define noexcept
#endif
namespace qhipster {
/// \class AlignedAllocator
/// @brief An allocator returning aligned memory
///
/// This class provides an aligned C++98 and C++11 conforming allocator.
/// \pre The alignment must be a power of 2.
template <typename T, unsigned int Alignment>
class AlignedAllocator
{
public:
typedef T* pointer;
typedef T const* const_pointer;
typedef T& reference;
typedef T const& const_reference;
typedef T value_type;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
template <typename U>
struct rebind
{
typedef AlignedAllocator<U, Alignment> other;
};
AlignedAllocator() noexcept {}
AlignedAllocator(AlignedAllocator const&) noexcept {}
template <typename U>
AlignedAllocator(AlignedAllocator<U, Alignment> const&) noexcept
{
}
pointer allocate(size_type n)
{
pointer p;
static_assert(isPowerOf2(Alignment), "Alignment not a power of 2");
#ifdef _WIN32
p = reinterpret_cast<pointer>(_aligned_malloc(n * sizeof(T), Alignment));
if (p == 0) throw std::bad_alloc();
#else
if (posix_memalign(reinterpret_cast<void**>(&p), Alignment, n * sizeof(T)))
throw std::bad_alloc();
#endif
return p;
}
void deallocate(pointer p, size_type) noexcept
{
#ifdef _WIN32
_aligned_free(p);
#else
std::free(p);
#endif
}
size_type max_size() const noexcept
{
std::allocator<T> a;
return a.max_size();
}
#if __cplusplus >= 201103L
template <typename C, class... Args>
void construct(C* c, Args&&... args)
{
new ((void*)c) C(std::forward<Args>(args)...);
}
#else
void construct(pointer p, const_reference t) { new ((void*)p) T(t); }
#endif
template <typename C>
void destroy(C* c)
{
c->~C();
}
bool operator==(AlignedAllocator const&) const noexcept { return true; }
bool operator!=(AlignedAllocator const&) const noexcept { return false; }
template <typename U, unsigned int UAlignment>
bool operator==(AlignedAllocator<U, UAlignment> const&) const noexcept
{
return false;
}
template <typename U, unsigned int UAlignment>
bool operator!=(AlignedAllocator<U, UAlignment> const&) const noexcept
{
return true;
}
};
} // namespace qhipster
#if __cplusplus < 201103L
#undef noexcept
#endif
/** @}*/
#endif // header guard IQS_ALIGNED_ALLOCATOR_HPP