Systemd/src/basic/unaligned.h
2016-06-06 19:59:09 +02:00

130 lines
3.6 KiB
C

#pragma once
/***
This file is part of systemd.
Copyright 2014 Tom Gundersen
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <endian.h>
#include <stdint.h>
/* BE */
static inline uint16_t unaligned_read_be16(const void *_u) {
const uint8_t *u = _u;
return (((uint16_t) u[0]) << 8) |
((uint16_t) u[1]);
}
static inline uint32_t unaligned_read_be32(const void *_u) {
const uint8_t *u = _u;
return (((uint32_t) unaligned_read_be16(u)) << 16) |
((uint32_t) unaligned_read_be16(u + 2));
}
static inline uint64_t unaligned_read_be64(const void *_u) {
const uint8_t *u = _u;
return (((uint64_t) unaligned_read_be32(u)) << 32) |
((uint64_t) unaligned_read_be32(u + 4));
}
static inline void unaligned_write_be16(void *_u, uint16_t a) {
uint8_t *u = _u;
u[0] = (uint8_t) (a >> 8);
u[1] = (uint8_t) a;
}
static inline void unaligned_write_be32(void *_u, uint32_t a) {
uint8_t *u = _u;
unaligned_write_be16(u, (uint16_t) (a >> 16));
unaligned_write_be16(u + 2, (uint16_t) a);
}
static inline void unaligned_write_be64(void *_u, uint64_t a) {
uint8_t *u = _u;
unaligned_write_be32(u, (uint32_t) (a >> 32));
unaligned_write_be32(u + 4, (uint32_t) a);
}
/* LE */
static inline uint16_t unaligned_read_le16(const void *_u) {
const uint8_t *u = _u;
return (((uint16_t) u[1]) << 8) |
((uint16_t) u[0]);
}
static inline uint32_t unaligned_read_le32(const void *_u) {
const uint8_t *u = _u;
return (((uint32_t) unaligned_read_le16(u + 2)) << 16) |
((uint32_t) unaligned_read_le16(u));
}
static inline uint64_t unaligned_read_le64(const void *_u) {
const uint8_t *u = _u;
return (((uint64_t) unaligned_read_le32(u + 4)) << 32) |
((uint64_t) unaligned_read_le32(u));
}
static inline void unaligned_write_le16(void *_u, uint16_t a) {
uint8_t *u = _u;
u[0] = (uint8_t) a;
u[1] = (uint8_t) (a >> 8);
}
static inline void unaligned_write_le32(void *_u, uint32_t a) {
uint8_t *u = _u;
unaligned_write_le16(u, (uint16_t) a);
unaligned_write_le16(u + 2, (uint16_t) (a >> 16));
}
static inline void unaligned_write_le64(void *_u, uint64_t a) {
uint8_t *u = _u;
unaligned_write_le32(u, (uint32_t) a);
unaligned_write_le32(u + 4, (uint32_t) (a >> 32));
}
#if __BYTE_ORDER == __BIG_ENDIAN
#define unaligned_read_ne16 unaligned_read_be16
#define unaligned_read_ne32 unaligned_read_be32
#define unaligned_read_ne64 unaligned_read_be64
#define unaligned_write_ne16 unaligned_write_be16
#define unaligned_write_ne32 unaligned_write_be32
#define unaligned_write_ne64 unaligned_write_be64
#else
#define unaligned_read_ne16 unaligned_read_le16
#define unaligned_read_ne32 unaligned_read_le32
#define unaligned_read_ne64 unaligned_read_le64
#define unaligned_write_ne16 unaligned_write_le16
#define unaligned_write_ne32 unaligned_write_le32
#define unaligned_write_ne64 unaligned_write_le64
#endif