diff options
Diffstat (limited to 'ext/protozero/include/protozero/byteswap.hpp')
-rw-r--r-- | ext/protozero/include/protozero/byteswap.hpp | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/ext/protozero/include/protozero/byteswap.hpp b/ext/protozero/include/protozero/byteswap.hpp new file mode 100644 index 0000000..799d179 --- /dev/null +++ b/ext/protozero/include/protozero/byteswap.hpp @@ -0,0 +1,99 @@ +#ifndef PROTOZERO_BYTESWAP_HPP +#define PROTOZERO_BYTESWAP_HPP + +/***************************************************************************** + +protozero - Minimalistic protocol buffer decoder and encoder in C++. + +This file is from https://github.com/mapbox/protozero where you can find more +documentation. + +*****************************************************************************/ + +/** + * @file byteswap.hpp + * + * @brief Contains functions to swap bytes in values (for different endianness). + */ + +#include "config.hpp" + +#include <cstdint> + +namespace protozero { +namespace detail { + +inline uint32_t byteswap_impl(uint32_t value) noexcept { +#ifdef PROTOZERO_USE_BUILTIN_BSWAP + return __builtin_bswap32(value); +#else + return ((value & 0xff000000U) >> 24U) | + ((value & 0x00ff0000U) >> 8U) | + ((value & 0x0000ff00U) << 8U) | + ((value & 0x000000ffU) << 24U); +#endif +} + +inline uint64_t byteswap_impl(uint64_t value) noexcept { +#ifdef PROTOZERO_USE_BUILTIN_BSWAP + return __builtin_bswap64(value); +#else + return ((value & 0xff00000000000000ULL) >> 56U) | + ((value & 0x00ff000000000000ULL) >> 40U) | + ((value & 0x0000ff0000000000ULL) >> 24U) | + ((value & 0x000000ff00000000ULL) >> 8U) | + ((value & 0x00000000ff000000ULL) << 8U) | + ((value & 0x0000000000ff0000ULL) << 24U) | + ((value & 0x000000000000ff00ULL) << 40U) | + ((value & 0x00000000000000ffULL) << 56U); +#endif +} + +} // end namespace detail + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(uint32_t* ptr) noexcept { + *ptr = detail::byteswap_impl(*ptr); +} + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(uint64_t* ptr) noexcept { + *ptr = detail::byteswap_impl(*ptr); +} + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(int32_t* ptr) noexcept { + auto* bptr = reinterpret_cast<uint32_t*>(ptr); + *bptr = detail::byteswap_impl(*bptr); +} + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(int64_t* ptr) noexcept { + auto* bptr = reinterpret_cast<uint64_t*>(ptr); + *bptr = detail::byteswap_impl(*bptr); +} + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(float* ptr) noexcept { + auto* bptr = reinterpret_cast<uint32_t*>(ptr); + *bptr = detail::byteswap_impl(*bptr); +} + +/// byteswap the data pointed to by ptr in-place. +inline void byteswap_inplace(double* ptr) noexcept { + auto* bptr = reinterpret_cast<uint64_t*>(ptr); + *bptr = detail::byteswap_impl(*bptr); +} + +namespace detail { + + // Added for backwards compatibility with any code that might use this + // function (even if it shouldn't have). Will be removed in a later + // version of protozero. + using ::protozero::byteswap_inplace; + +} // end namespace detail + +} // end namespace protozero + +#endif // PROTOZERO_BYTESWAP_HPP |