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Diffstat (limited to '')
-rw-r--r-- | src/common/alignment.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/src/common/alignment.h b/src/common/alignment.h index d94a2291f..88d5d3a65 100644 --- a/src/common/alignment.h +++ b/src/common/alignment.h @@ -3,6 +3,7 @@ #pragma once #include <cstddef> +#include <memory> #include <type_traits> namespace Common { @@ -20,6 +21,12 @@ constexpr T AlignDown(T value, std::size_t 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; @@ -31,4 +38,63 @@ constexpr bool IsWordAligned(T value) { return (value & 0b11) == 0; } +template <typename T, std::size_t Align = 16> +class AlignmentAllocator { +public: + using value_type = T; + using size_type = std::size_t; + using difference_type = std::ptrdiff_t; + + using pointer = T*; + using const_pointer = const T*; + + using reference = T&; + using const_reference = const T&; + +public: + pointer address(reference r) noexcept { + return std::addressof(r); + } + + const_pointer address(const_reference r) const noexcept { + return std::addressof(r); + } + + pointer allocate(size_type n) { + return static_cast<pointer>(::operator new (n, std::align_val_t{Align})); + } + + void deallocate(pointer p, size_type) { + ::operator delete (p, std::align_val_t{Align}); + } + + void construct(pointer p, const value_type& wert) { + new (p) value_type(wert); + } + + void destroy(pointer p) { + p->~value_type(); + } + + size_type max_size() const noexcept { + return size_type(-1) / sizeof(value_type); + } + + template <typename T2> + struct rebind { + using other = AlignmentAllocator<T2, Align>; + }; + + bool operator!=(const AlignmentAllocator<T, Align>& other) const noexcept { + 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 noexcept { + return true; + } +}; + } // namespace Common |