qemu/bswap: Replace bswapXX() by compiler __builtin_bswap()

Use the compiler built-in function to byte swap values,
as the compiler is clever and will fold constants.

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230111163147.71761-2-philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This commit is contained in:
Philippe Mathieu-Daudé 2023-01-11 17:31:42 +01:00 committed by Thomas Huth
parent 2b5e0c9ff8
commit 6366ca31ef

View File

@ -37,31 +37,12 @@ static inline uint64_t bswap64(uint64_t x)
#endif #endif
#ifdef BSWAP_FROM_FALLBACKS #ifdef BSWAP_FROM_FALLBACKS
static inline uint16_t bswap16(uint16_t x) #undef bswap16
{ #define bswap16(_x) __builtin_bswap16(_x)
return (((x & 0x00ff) << 8) | #undef bswap32
((x & 0xff00) >> 8)); #define bswap32(_x) __builtin_bswap32(_x)
} #undef bswap64
#define bswap64(_x) __builtin_bswap64(_x)
static inline uint32_t bswap32(uint32_t x)
{
return (((x & 0x000000ffU) << 24) |
((x & 0x0000ff00U) << 8) |
((x & 0x00ff0000U) >> 8) |
((x & 0xff000000U) >> 24));
}
static inline uint64_t bswap64(uint64_t x)
{
return (((x & 0x00000000000000ffULL) << 56) |
((x & 0x000000000000ff00ULL) << 40) |
((x & 0x0000000000ff0000ULL) << 24) |
((x & 0x00000000ff000000ULL) << 8) |
((x & 0x000000ff00000000ULL) >> 8) |
((x & 0x0000ff0000000000ULL) >> 24) |
((x & 0x00ff000000000000ULL) >> 40) |
((x & 0xff00000000000000ULL) >> 56));
}
#endif #endif
#undef BSWAP_FROM_BYTESWAP #undef BSWAP_FROM_BYTESWAP