Merge pull request #2392 from lioncash/swap

common/swap: Minor cleanup and improvements to byte swapping functions
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bunnei 2019-04-12 21:52:16 -04:00 committed by GitHub
commit 0faf7b17a1
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@ -21,11 +21,6 @@
#if defined(_MSC_VER) #if defined(_MSC_VER)
#include <cstdlib> #include <cstdlib>
#elif defined(__linux__)
#include <byteswap.h>
#elif defined(__Bitrig__) || defined(__DragonFly__) || defined(__FreeBSD__) || \
defined(__NetBSD__) || defined(__OpenBSD__)
#include <sys/endian.h>
#endif #endif
#include <cstring> #include <cstring>
#include "common/common_types.h" #include "common/common_types.h"
@ -62,86 +57,49 @@
namespace Common { namespace Common {
#ifdef _MSC_VER #ifdef _MSC_VER
inline u16 swap16(u16 _data) { [[nodiscard]] inline u16 swap16(u16 data) noexcept {
return _byteswap_ushort(_data); return _byteswap_ushort(data);
} }
inline u32 swap32(u32 _data) { [[nodiscard]] inline u32 swap32(u32 data) noexcept {
return _byteswap_ulong(_data); return _byteswap_ulong(data);
} }
inline u64 swap64(u64 _data) { [[nodiscard]] inline u64 swap64(u64 data) noexcept {
return _byteswap_uint64(_data); return _byteswap_uint64(data);
} }
#elif defined(ARCHITECTURE_ARM) && (__ARM_ARCH >= 6) #elif defined(__clang__) || defined(__GNUC__)
inline u16 swap16(u16 _data) { #if defined(__Bitrig__) || defined(__OpenBSD__)
u32 data = _data;
__asm__("rev16 %0, %1\n" : "=l"(data) : "l"(data));
return (u16)data;
}
inline u32 swap32(u32 _data) {
__asm__("rev %0, %1\n" : "=l"(_data) : "l"(_data));
return _data;
}
inline u64 swap64(u64 _data) {
return ((u64)swap32(_data) << 32) | swap32(_data >> 32);
}
#elif __linux__
inline u16 swap16(u16 _data) {
return bswap_16(_data);
}
inline u32 swap32(u32 _data) {
return bswap_32(_data);
}
inline u64 swap64(u64 _data) {
return bswap_64(_data);
}
#elif __APPLE__
inline __attribute__((always_inline)) u16 swap16(u16 _data) {
return (_data >> 8) | (_data << 8);
}
inline __attribute__((always_inline)) u32 swap32(u32 _data) {
return __builtin_bswap32(_data);
}
inline __attribute__((always_inline)) u64 swap64(u64 _data) {
return __builtin_bswap64(_data);
}
#elif defined(__Bitrig__) || defined(__OpenBSD__)
// redefine swap16, swap32, swap64 as inline functions // redefine swap16, swap32, swap64 as inline functions
#undef swap16 #undef swap16
#undef swap32 #undef swap32
#undef swap64 #undef swap64
inline u16 swap16(u16 _data) { #endif
return __swap16(_data); [[nodiscard]] inline u16 swap16(u16 data) noexcept {
return __builtin_bswap16(data);
} }
inline u32 swap32(u32 _data) { [[nodiscard]] inline u32 swap32(u32 data) noexcept {
return __swap32(_data); return __builtin_bswap32(data);
} }
inline u64 swap64(u64 _data) { [[nodiscard]] inline u64 swap64(u64 data) noexcept {
return __swap64(_data); return __builtin_bswap64(data);
}
#elif defined(__DragonFly__) || defined(__FreeBSD__) || defined(__NetBSD__)
inline u16 swap16(u16 _data) {
return bswap16(_data);
}
inline u32 swap32(u32 _data) {
return bswap32(_data);
}
inline u64 swap64(u64 _data) {
return bswap64(_data);
} }
#else #else
// Slow generic implementation. // Generic implementation.
inline u16 swap16(u16 data) { [[nodiscard]] inline u16 swap16(u16 data) noexcept {
return (data >> 8) | (data << 8); return (data >> 8) | (data << 8);
} }
inline u32 swap32(u32 data) { [[nodiscard]] inline u32 swap32(u32 data) noexcept {
return (swap16(data) << 16) | swap16(data >> 16); return ((data & 0xFF000000U) >> 24) | ((data & 0x00FF0000U) >> 8) |
((data & 0x0000FF00U) << 8) | ((data & 0x000000FFU) << 24);
} }
inline u64 swap64(u64 data) { [[nodiscard]] inline u64 swap64(u64 data) noexcept {
return ((u64)swap32(data) << 32) | swap32(data >> 32); return ((data & 0xFF00000000000000ULL) >> 56) | ((data & 0x00FF000000000000ULL) >> 40) |
((data & 0x0000FF0000000000ULL) >> 24) | ((data & 0x000000FF00000000ULL) >> 8) |
((data & 0x00000000FF000000ULL) << 8) | ((data & 0x0000000000FF0000ULL) << 24) |
((data & 0x000000000000FF00ULL) << 40) | ((data & 0x00000000000000FFULL) << 56);
} }
#endif #endif
inline float swapf(float f) { [[nodiscard]] inline float swapf(float f) noexcept {
static_assert(sizeof(u32) == sizeof(float), "float must be the same size as uint32_t."); static_assert(sizeof(u32) == sizeof(float), "float must be the same size as uint32_t.");
u32 value; u32 value;
@ -153,7 +111,7 @@ inline float swapf(float f) {
return f; return f;
} }
inline double swapd(double f) { [[nodiscard]] inline double swapd(double f) noexcept {
static_assert(sizeof(u64) == sizeof(double), "double must be the same size as uint64_t."); static_assert(sizeof(u64) == sizeof(double), "double must be the same size as uint64_t.");
u64 value; u64 value;