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Diffstat (limited to 'lib/ccan/endian/endian.h')
| -rw-r--r-- | lib/ccan/endian/endian.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/lib/ccan/endian/endian.h b/lib/ccan/endian/endian.h new file mode 100644 index 00000000000..baee60be144 --- /dev/null +++ b/lib/ccan/endian/endian.h @@ -0,0 +1,226 @@ +#ifndef CCAN_ENDIAN_H +#define CCAN_ENDIAN_H +#include <stdint.h> +#include "config.h" + +#if HAVE_BYTESWAP_H +#include <byteswap.h> +#else +/** + * bswap_16 - reverse bytes in a uint16_t value. + * @val: value whose bytes to swap. + * + * Example: + * // Output contains "1024 is 4 as two bytes reversed" + * printf("1024 is %u as two bytes reversed\n", bswap_16(1024)); + */ +static inline uint16_t bswap_16(uint16_t val) +{ + return ((val & (uint16_t)0x00ffU) << 8) + | ((val & (uint16_t)0xff00U) >> 8); +} + +/** + * bswap_32 - reverse bytes in a uint32_t value. + * @val: value whose bytes to swap. + * + * Example: + * // Output contains "1024 is 262144 as four bytes reversed" + * printf("1024 is %u as four bytes reversed\n", bswap_32(1024)); + */ +static inline uint32_t bswap_32(uint32_t val) +{ + return ((val & (uint32_t)0x000000ffUL) << 24) + | ((val & (uint32_t)0x0000ff00UL) << 8) + | ((val & (uint32_t)0x00ff0000UL) >> 8) + | ((val & (uint32_t)0xff000000UL) >> 24); +} +#endif /* !HAVE_BYTESWAP_H */ + +#if !HAVE_BSWAP_64 +/** + * bswap_64 - reverse bytes in a uint64_t value. + * @val: value whose bytes to swap. + * + * Example: + * // Output contains "1024 is 1125899906842624 as eight bytes reversed" + * printf("1024 is %llu as eight bytes reversed\n", + * (unsigned long long)bswap_64(1024)); + */ +static inline uint64_t bswap_64(uint64_t val) +{ + return ((val & (uint64_t)0x00000000000000ffULL) << 56) + | ((val & (uint64_t)0x000000000000ff00ULL) << 40) + | ((val & (uint64_t)0x0000000000ff0000ULL) << 24) + | ((val & (uint64_t)0x00000000ff000000ULL) << 8) + | ((val & (uint64_t)0x000000ff00000000ULL) >> 8) + | ((val & (uint64_t)0x0000ff0000000000ULL) >> 24) + | ((val & (uint64_t)0x00ff000000000000ULL) >> 40) + | ((val & (uint64_t)0xff00000000000000ULL) >> 56); +} +#endif + +/* Sanity check the defines. We don't handle weird endianness. */ +#if !HAVE_LITTLE_ENDIAN && !HAVE_BIG_ENDIAN +#error "Unknown endian" +#elif HAVE_LITTLE_ENDIAN && HAVE_BIG_ENDIAN +#error "Can't compile for both big and little endian." +#endif + +/** + * cpu_to_le64 - convert a uint64_t value to little-endian + * @native: value to convert + */ +static inline uint64_t cpu_to_le64(uint64_t native) +{ +#if HAVE_LITTLE_ENDIAN + return native; +#else + return bswap_64(native); +#endif +} + +/** + * cpu_to_le32 - convert a uint32_t value to little-endian + * @native: value to convert + */ +static inline uint32_t cpu_to_le32(uint32_t native) +{ +#if HAVE_LITTLE_ENDIAN + return native; +#else + return bswap_32(native); +#endif +} + +/** + * cpu_to_le16 - convert a uint16_t value to little-endian + * @native: value to convert + */ +static inline uint16_t cpu_to_le16(uint16_t native) +{ +#if HAVE_LITTLE_ENDIAN + return native; +#else + return bswap_16(native); +#endif +} + +/** + * le64_to_cpu - convert a little-endian uint64_t value + * @le_val: little-endian value to convert + */ +static inline uint64_t le64_to_cpu(uint64_t le_val) +{ +#if HAVE_LITTLE_ENDIAN + return le_val; +#else + return bswap_64(le_val); +#endif +} + +/** + * le32_to_cpu - convert a little-endian uint32_t value + * @le_val: little-endian value to convert + */ +static inline uint32_t le32_to_cpu(uint32_t le_val) +{ +#if HAVE_LITTLE_ENDIAN + return le_val; +#else + return bswap_32(le_val); +#endif +} + +/** + * le16_to_cpu - convert a little-endian uint16_t value + * @le_val: little-endian value to convert + */ +static inline uint16_t le16_to_cpu(uint16_t le_val) +{ +#if HAVE_LITTLE_ENDIAN + return le_val; +#else + return bswap_16(le_val); +#endif +} + +/** + * cpu_to_be64 - convert a uint64_t value to big endian. + * @native: value to convert + */ +static inline uint64_t cpu_to_be64(uint64_t native) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_64(native); +#else + return native; +#endif +} + +/** + * cpu_to_be32 - convert a uint32_t value to big endian. + * @native: value to convert + */ +static inline uint32_t cpu_to_be32(uint32_t native) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_32(native); +#else + return native; +#endif +} + +/** + * cpu_to_be16 - convert a uint16_t value to big endian. + * @native: value to convert + */ +static inline uint16_t cpu_to_be16(uint16_t native) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_16(native); +#else + return native; +#endif +} + +/** + * be64_to_cpu - convert a big-endian uint64_t value + * @be_val: big-endian value to convert + */ +static inline uint64_t be64_to_cpu(uint64_t be_val) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_64(be_val); +#else + return be_val; +#endif +} + +/** + * be32_to_cpu - convert a big-endian uint32_t value + * @be_val: big-endian value to convert + */ +static inline uint32_t be32_to_cpu(uint32_t be_val) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_32(be_val); +#else + return be_val; +#endif +} + +/** + * be16_to_cpu - convert a big-endian uint16_t value + * @be_val: big-endian value to convert + */ +static inline uint16_t be16_to_cpu(uint16_t be_val) +{ +#if HAVE_LITTLE_ENDIAN + return bswap_16(be_val); +#else + return be_val; +#endif +} + +#endif /* CCAN_ENDIAN_H */ |