/* * Copyright (c) 2022-2024 SAULX * SPDX-License-Identifier: MIT */ #pragma once #ifndef _SELVA_ENDIAN_H_ #define _SELVA_ENDIAN_H_ #include #include /* * NOTICE * This header conflicts with `endian.h` on Linux/glibc and gets included at * least by `sys/types.h`. This is not a big problem because we implement the * same functionality + some extras. * The original header could be included with `#include_next`. Isn't it pretty * stupid that we can override system headers included by system headers in * this way? */ _Static_assert(sizeof(double) == 8, "Only 64bit doubles are supported"); #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ #ifndef htobe16 #define htobe16(x) __builtin_bswap16(x) #define htole16(x) (x) #define be16toh(x) __builtin_bswap16(x) #define le16toh(x) (x) #endif #ifndef htobe32 #define htobe32(x) __builtin_bswap32(x) #define htole32(x) (x) #define be32toh(x) __builtin_bswap32(x) #define le32toh(x) (x) #endif #ifndef htobe64 #define htobe64(x) __builtin_bswap64(x) #define htole64(x) (x) #define be64toh(x) __builtin_bswap64(x) #define le64toh(x) (x) #endif static inline void htoledouble(char buf[8], double x) { #if __FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__ /* * x: 4 5 6 7 0 1 2 3 * 0 1 2 3 4 5 6 7 */ char s[8]; __builtin_memcpy(s, &x, 8); buf[0] = s[4]; buf[1] = s[5]; buf[2] = s[6]; buf[3] = s[7]; buf[4] = s[0]; buf[5] = s[1]; buf[6] = s[2]; buf[7] = s[3]; #else __builtin_memcpy(buf, &x, 8); #endif } static inline double ledoubletoh(const char buf[8]) { #if __FLOAT_WORD_ORDER__ == __ORDER_BIG_ENDIAN__ char s[8]; double x; s[0] = buf[4]; s[1] = buf[5]; s[2] = buf[6]; s[3] = buf[7]; s[4] = buf[0]; s[5] = buf[1]; s[6] = buf[2]; s[7] = buf[3]; __builtin_memcpy(&x, s, sizeof(double)); return x; #else double x; __builtin_memcpy(&x, buf, sizeof(double)); return x; #endif } #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ #ifndef htobe16 #define htobe16(x) (x) #define htole16(x) __builtin_bswap16(x) #define be16toh(x) (x) #define le16toh(x) __builtin_bswap16(x) #endif #ifndef htobe32 #define htobe32(x) (x) #define htole32(x) __builtin_bswap32(x) #define be32toh(x) (x) #define le32toh(x) __builtin_bswap32(x) #endif #ifndef htobe64 #define htobe64(x) (x) #define htole64(x) __builtin_bswap64(x) #define be64toh(x) (x) #define le64toh(x) __builtin_bswap64(x) #endif static inline void htoledouble(char buf[8], double x) { #if __FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__ /* * x: 3 2 1 0 7 6 5 4 * s: 0 1 2 3 4 5 6 7 */ char s[8]; __builtin_memcpy(s, &x, 8); buf[0] = s[3]; buf[1] = s[2]; buf[2] = s[1]; buf[3] = s[0]; buf[4] = s[7]; buf[5] = s[6]; buf[6] = s[5]; buf[7] = s[4]; #else /* * x: 7 6 5 4 3 2 1 0 * s: 0 1 2 3 4 5 6 7 */ char s[8]; __builtin_memcpy(s, &x, 8); buf[0] = s[7]; buf[1] = s[6]; buf[2] = s[5]; buf[3] = s[4]; buf[4] = s[3]; buf[5] = s[2]; buf[6] = s[1]; buf[7] = s[0]; #endif } static inline double ledoubletoh(const char buf[8]) { char s[8]; double x; #if __FLOAT_WORD_ORDER__ == __ORDER_LITTLE_ENDIAN__ s[0] = buf[3]; s[1] = buf[2]; s[2] = buf[1]; s[3] = buf[0]; s[4] = buf[7]; s[5] = buf[6]; s[6] = buf[5]; s[7] = buf[4]; #else s[0] = buf[7]; s[1] = buf[6]; s[2] = buf[5]; s[3] = buf[4]; s[4] = buf[3]; s[5] = buf[2]; s[6] = buf[1]; s[7] = buf[0]; #endif __builtin_memcpy(&x, s, sizeof(double)); return x; } #else #error "Machine byte order not supported" #endif #if __linux__ /** * Type generic Host to BE. */ #define htobe(v) _Generic((v), \ uint16_t: htobe16(v), \ int16_t: (int16_t)htobe16(v), \ uint32_t: htobe32(v), \ int32_t: (int32_t)htobe32(v), \ uint64_t: htobe64(v), \ int64_t: (int64_t)htobe64(v), \ unsigned long long: (unsigned long long)htobe64(v), \ long long: (int64_t)htobe64(v)) /** * Type generic Host to LE. */ #define htole(v) _Generic((v), \ uint16_t: htole16(v), \ int16_t: (int16_t)htole16(v), \ uint32_t: htole32(v), \ int32_t: (int32_t)htole32(v), \ uint64_t: htole64(v), \ int64_t: (int64_t)htole64(v), \ unsigned long long: (unsigned long long)htole64(v), \ long long: (int64_t)htole64(v)) /** * Type generic LE to Host. */ #define letoh(v) _Generic((v), \ uint16_t: le16toh(v), \ int16_t: (int16_t)le16toh(v), \ uint32_t: le32toh(v), \ int32_t: (int32_t)le32toh(v), \ uint64_t: le64toh(v), \ int64_t: (int64_t)le64toh(v), \ unsigned long long: (unsigned long long)le64toh(v), \ long long: (int64_t)le64toh(v)) /** * Type generic BE to Host. */ #define betoh(v) _Generic((v), \ uint16_t: be16toh(v), \ int16_t: (int16_t)be16toh(v), \ uint32_t: be32toh(v), \ int32_t: (int32_t)be32toh(v), \ uint64_t: be64toh(v), \ int64_t: (int64_t)be64toh(v), \ unsigned long long: (unsigned long long)be64toh(v), \ long long: (int64_t)be64toh(v)) /* 128-bit machines not supported atm. */ static_assert(sizeof(long long) == sizeof(uint64_t)); #else /** * Type generic Host to BE. */ #define htobe(v) _Generic((v), \ uint16_t: htobe16(v), \ int16_t: (int16_t)htobe16(v), \ uint32_t: htobe32(v), \ int32_t: (int32_t)htobe32(v), \ uint64_t: htobe64(v), \ size_t: htobe64(v), \ ssize_t: htobe64(v), \ int64_t: (int64_t)htobe64(v)) /** * Type generic Host to LE. */ #define htole(v) _Generic((v), \ uint16_t: htole16(v), \ int16_t: (int16_t)htole16(v), \ uint32_t: htole32(v), \ int32_t: (int32_t)htole32(v), \ uint64_t: htole64(v), \ size_t: htole64(v), \ ssize_t: htole64(v), \ int64_t: (int64_t)htole64(v)) /** * Type generic LE to Host. */ #define letoh(v) _Generic((v), \ uint16_t: le16toh(v), \ int16_t: (int16_t)le16toh(v), \ uint32_t: le32toh(v), \ int32_t: (int32_t)le32toh(v), \ uint64_t: le64toh(v), \ size_t: le64toh(v), \ ssize_t: le64toh(v), \ int64_t: (int64_t)le64toh(v)) /** * Type generic BE to Host. */ #define betoh(v) _Generic((v), \ uint16_t: be16toh(v), \ int16_t: (int16_t)be16toh(v), \ uint32_t: be32toh(v), \ int32_t: (int32_t)be32toh(v), \ uint64_t: be64toh(v), \ size_t: be64toh(v), \ ssize_t: be64toh(v), \ int64_t: (int64_t)be64toh(v)) #endif /* If this fails then htole and letoh will need some adjustment. */ static_assert(sizeof(size_t) == sizeof(uint64_t)); #endif /* _SELVA_ENDIAN_H_ */