1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 3 /* 4 * linux/byteorder/swab.h 5 * Byte-swapping, independently from CPU endianness 6 * swabXX[ps]?(foo) 7 * 8 * Francois-Rene Rideau <[email protected]> 19971205 9 * separated swab functions from cpu_to_XX, 10 * to clean up support for bizarre-endian architectures. 11 * 12 * See asm-i386/byteorder.h and such for examples of how to provide 13 * architecture-dependent optimized versions 14 * 15 */ 16 17 /* casts are necessary for constants, because we never know how for sure 18 * how U/UL/ULL map to __u16, __u32, __u64. At least not in a portable way. 19 */ 20 21 #ifndef _SWAB_H 22 #define _SWAB_H 23 24 #include <stdint.h> 25 26 #if ENV_ARMV4 27 #define swab16(x) \ 28 ((unsigned short)( \ 29 (((unsigned short)(x) & (unsigned short)0x00ffU) << 8) | \ 30 (((unsigned short)(x) & (unsigned short)0xff00U) >> 8))) 31 32 #define swab32(x) \ 33 ((unsigned int)( \ 34 (((unsigned int)(x) & 0x000000ffUL) << 24) | \ 35 (((unsigned int)(x) & 0x0000ff00UL) << 8) | \ 36 (((unsigned int)(x) & 0x00ff0000UL) >> 8) | \ 37 (((unsigned int)(x) & 0xff000000UL) >> 24))) 38 39 #define swab64(x) \ 40 ((uint64_t)( \ 41 (((uint64_t)(x) & (uint64_t)0x00000000000000ffULL) << 56) | \ 42 (((uint64_t)(x) & (uint64_t)0x000000000000ff00ULL) << 40) | \ 43 (((uint64_t)(x) & (uint64_t)0x0000000000ff0000ULL) << 24) | \ 44 (((uint64_t)(x) & (uint64_t)0x00000000ff000000ULL) << 8) | \ 45 (((uint64_t)(x) & (uint64_t)0x000000ff00000000ULL) >> 8) | \ 46 (((uint64_t)(x) & (uint64_t)0x0000ff0000000000ULL) >> 24) | \ 47 (((uint64_t)(x) & (uint64_t)0x00ff000000000000ULL) >> 40) | \ 48 (((uint64_t)(x) & (uint64_t)0xff00000000000000ULL) >> 56))) 49 #else /* ENV_ARMV4 */ 50 #define swab16(x) ((uint16_t)__builtin_bswap16(x)) 51 #define swab32(x) ((uint32_t)__builtin_bswap32(x)) 52 #define swab64(x) ((uint64_t)__builtin_bswap64(x)) 53 #endif /* !ENV_ARMV4 */ 54 55 #endif /* _SWAB_H */ 56