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// This file is under the public domain.
#pragma once
#include <cstddef>
#include <cstdlib>
#include <type_traits>
#include <malloc.h>
#include <stdlib.h>
namespace Common {
template <typename T>
constexpr T AlignUp(T value, std::size_t size) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return static_cast<T>(value + (size - value % size) % size);
}
template <typename T>
constexpr T AlignDown(T value, std::size_t size) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return static_cast<T>(value - value % size);
}
template <typename T>
constexpr T AlignBits(T value, std::size_t align) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return static_cast<T>((value + ((1ULL << align) - 1)) >> align << align);
}
template <typename T>
constexpr bool Is4KBAligned(T value) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return (value & 0xFFF) == 0;
}
template <typename T>
constexpr bool IsWordAligned(T value) {
static_assert(std::is_unsigned_v<T>, "T must be an unsigned value.");
return (value & 0b11) == 0;
}
template <typename T, std::size_t Align = 16>
class AlignmentAllocator {
public:
typedef T value_type;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
typedef T* pointer;
typedef const T* const_pointer;
typedef T& reference;
typedef const T& const_reference;
public:
inline AlignmentAllocator() throw() {}
template <typename T2>
inline AlignmentAllocator(const AlignmentAllocator<T2, Align>&) throw() {}
inline ~AlignmentAllocator() throw() {}
inline pointer adress(reference r) {
return &r;
}
inline const_pointer adress(const_reference r) const {
return &r;
}
#if (defined _MSC_VER)
inline pointer allocate(size_type n) {
return (pointer)_aligned_malloc(n * sizeof(value_type), Align);
}
inline void deallocate(pointer p, size_type) {
_aligned_free(p);
}
#else
inline pointer allocate(size_type n) {
return (pointer)std::aligned_alloc(Align, n * sizeof(value_type));
}
inline void deallocate(pointer p, size_type) {
std::free(p);
}
#endif
inline void construct(pointer p, const value_type& wert) {
new (p) value_type(wert);
}
inline void destroy(pointer p) {
p->~value_type();
}
inline size_type max_size() const throw() {
return size_type(-1) / sizeof(value_type);
}
template <typename T2>
struct rebind {
typedef AlignmentAllocator<T2, Align> other;
};
bool operator!=(const AlignmentAllocator<T, Align>& other) const {
return !(*this == other);
}
// Returns true if and only if storage allocated from *this
// can be deallocated from other, and vice versa.
// Always returns true for stateless allocators.
bool operator==(const AlignmentAllocator<T, Align>& other) const {
return true;
}
};
} // namespace Common
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