diff options
Diffstat (limited to 'gpxe/src/arch/i386/include/bits/byteswap.h')
-rw-r--r-- | gpxe/src/arch/i386/include/bits/byteswap.h | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/gpxe/src/arch/i386/include/bits/byteswap.h b/gpxe/src/arch/i386/include/bits/byteswap.h new file mode 100644 index 00000000..54b93ab9 --- /dev/null +++ b/gpxe/src/arch/i386/include/bits/byteswap.h @@ -0,0 +1,76 @@ +#ifndef ETHERBOOT_BITS_BYTESWAP_H +#define ETHERBOOT_BITS_BYTESWAP_H + +static inline __attribute__ ((always_inline, const)) uint16_t +__i386_bswap_16(uint16_t x) +{ + __asm__("xchgb %b0,%h0\n\t" + : "=q" (x) + : "0" (x)); + return x; +} + +static inline __attribute__ ((always_inline, const)) uint32_t +__i386_bswap_32(uint32_t x) +{ + __asm__("xchgb %b0,%h0\n\t" + "rorl $16,%0\n\t" + "xchgb %b0,%h0" + : "=q" (x) + : "0" (x)); + return x; +} + +static inline __attribute__ ((always_inline, const)) uint64_t +__i386_bswap_64(uint64_t x) +{ + union { + uint64_t qword; + uint32_t dword[2]; + } u; + + u.qword = x; + u.dword[0] = __i386_bswap_32(u.dword[0]); + u.dword[1] = __i386_bswap_32(u.dword[1]); + __asm__("xchgl %0,%1" + : "=r" ( u.dword[0] ), "=r" ( u.dword[1] ) + : "0" ( u.dword[0] ), "1" ( u.dword[1] ) ); + return u.qword; +} + +#define __bswap_constant_16(x) \ + ((uint16_t)((((uint16_t)(x) & 0x00ff) << 8) | \ + (((uint16_t)(x) & 0xff00) >> 8))) + +#define __bswap_constant_32(x) \ + ((uint32_t)((((uint32_t)(x) & 0x000000ffU) << 24) | \ + (((uint32_t)(x) & 0x0000ff00U) << 8) | \ + (((uint32_t)(x) & 0x00ff0000U) >> 8) | \ + (((uint32_t)(x) & 0xff000000U) >> 24))) + +#define __bswap_constant_64(x) \ + ((uint64_t)((((uint64_t)(x) & 0x00000000000000ffULL) << 56) | \ + (((uint64_t)(x) & 0x000000000000ff00ULL) << 40) | \ + (((uint64_t)(x) & 0x0000000000ff0000ULL) << 24) | \ + (((uint64_t)(x) & 0x00000000ff000000ULL) << 8) | \ + (((uint64_t)(x) & 0x000000ff00000000ULL) >> 8) | \ + (((uint64_t)(x) & 0x0000ff0000000000ULL) >> 24) | \ + (((uint64_t)(x) & 0x00ff000000000000ULL) >> 40) | \ + (((uint64_t)(x) & 0xff00000000000000ULL) >> 56))) + +#define __bswap_16(x) \ + ((uint16_t)(__builtin_constant_p(x) ? \ + __bswap_constant_16(x) : \ + __i386_bswap_16(x))) + +#define __bswap_32(x) \ + ((uint32_t)(__builtin_constant_p(x) ? \ + __bswap_constant_32(x) : \ + __i386_bswap_32(x))) + +#define __bswap_64(x) \ + ((uint64_t)(__builtin_constant_p(x) ? \ + __bswap_constant_64(x) : \ + __i386_bswap_64(x))) + +#endif /* ETHERBOOT_BITS_BYTESWAP_H */ |