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utils: use constant byte-order conversion

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Simplifies portability and ensures that cpu_to_* can be used in const
declarations. If the architecture has special instructions, the compiler
should be able to detect the pattern and use them.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
This commit is contained in:
Felix Fietkau 2018-03-21 17:53:40 +01:00
parent 3aad2948eb
commit eebe3fcd2a
1 changed files with 33 additions and 26 deletions
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59
utils.h
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@ -81,16 +81,10 @@ int clock_gettime(int type, struct timespec *tv);
#elif defined(__APPLE__)
#include <machine/endian.h>
#include <machine/byte_order.h>
#define bswap_32(x) OSSwapInt32(x)
#define bswap_64(x) OSSwapInt64(x)
#elif defined(__FreeBSD__)
#include <sys/endian.h>
#define bswap_32(x) bswap32(x)
#define bswap_64(x) bswap64(x)
#else
#include <machine/endian.h>
#define bswap_32(x) swap32(x)
#define bswap_64(x) swap64(x)
#endif
#ifndef __BYTE_ORDER
@ -103,28 +97,41 @@ int clock_gettime(int type, struct timespec *tv);
#define __LITTLE_ENDIAN LITTLE_ENDIAN
#endif
#define __constant_swap16(x) ((uint16_t)( \
(((uint16_t)(x) & (uint16_t)0x00ffU) << 8) | \
(((uint16_t)(x) & (uint16_t)0xff00U) >> 8)))
#define __constant_swap32(x) ((uint32_t)( \
(((uint32_t)(x) & (uint32_t)0x000000ffUL) << 24) | \
(((uint32_t)(x) & (uint32_t)0x0000ff00UL) << 8) | \
(((uint32_t)(x) & (uint32_t)0x00ff0000UL) >> 8) | \
(((uint32_t)(x) & (uint32_t)0xff000000UL) >> 24)))
#define __constant_swap64(x) ((uint64_t)( \
(((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \
(((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \
(((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \
(((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \
(((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \
(((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \
(((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \
(((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56)))
static inline uint16_t __u_bswap16(uint16_t val)
{
return ((val >> 8) & 0xffu) | ((val & 0xffu) << 8);
}
#if _GNUC_MIN_VER(4, 2)
#define __u_bswap32(x) __builtin_bswap32(x)
#define __u_bswap64(x) __builtin_bswap64(x)
#else
#define __u_bswap32(x) bswap_32(x)
#define __u_bswap64(x) bswap_64(x)
#endif
#if __BYTE_ORDER == __LITTLE_ENDIAN
#define cpu_to_be64(x) __u_bswap64(x)
#define cpu_to_be32(x) __u_bswap32(x)
#define cpu_to_be16(x) __u_bswap16((uint16_t) (x))
#define cpu_to_be64(x) __constant_swap64(x)
#define cpu_to_be32(x) __constant_swap32(x)
#define cpu_to_be16(x) __constant_swap16(x)
#define be64_to_cpu(x) __u_bswap64(x)
#define be32_to_cpu(x) __u_bswap32(x)
#define be16_to_cpu(x) __u_bswap16((uint16_t) (x))
#define be64_to_cpu(x) __constant_swap64(x)
#define be32_to_cpu(x) __constant_swap32(x)
#define be16_to_cpu(x) __constant_swap16(x)
#define cpu_to_le64(x) (x)
#define cpu_to_le32(x) (x)
@ -136,13 +143,13 @@ static inline uint16_t __u_bswap16(uint16_t val)
#else /* __BYTE_ORDER == __LITTLE_ENDIAN */
#define cpu_to_le64(x) __u_bswap64(x)
#define cpu_to_le32(x) __u_bswap32(x)
#define cpu_to_le16(x) __u_bswap16((uint16_t) (x))
#define cpu_to_le64(x) __constant_swap64(x)
#define cpu_to_le32(x) __constant_swap32(x)
#define cpu_to_le16(x) __constant_swap16(x)
#define le64_to_cpu(x) __u_bswap64(x)
#define le32_to_cpu(x) __u_bswap32(x)
#define le16_to_cpu(x) __u_bswap16((uint16_t) (x))
#define le64_to_cpu(x) __constant_swap64(x)
#define le32_to_cpu(x) __constant_swap32(x)
#define le16_to_cpu(x) __constant_swap16(x)
#define cpu_to_be64(x) (x)
#define cpu_to_be32(x) (x)