From 4544cd19e429975882e20fa89dab7e73956f26e4 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Tue, 15 Jul 2025 21:12:28 +0200 Subject: [PATCH] bswap.h: always overwrite ntohl/ ntohll macros The ntohl and htonl macros are redefined because the provided macros were not always optimal. Sometimes it was a function call, sometimes it was a macro which did the shifting. Using the 'bswap' opcode on x86 provides probably better performance than performing the shifting. These macros are only overwritten on x86 if the "optimized" version is available. The ntohll and htonll macros are not available on every platform (at least glibc does not provide them) which means they need to be defined once the endianness of the system is determined. In order to get a more symmetrical setup, redfine the macros once the endianness of the system has been determined. Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Junio C Hamano --- compat/bswap.h | 50 ++++++++++++++++++++++++-------------------------- 1 file changed, 24 insertions(+), 26 deletions(-) diff --git a/compat/bswap.h b/compat/bswap.h index fd604d9f7b..aeef304f67 100644 --- a/compat/bswap.h +++ b/compat/bswap.h @@ -87,27 +87,6 @@ static inline uint64_t git_bswap64(uint64_t x) #endif -#if defined(bswap32) - -#undef ntohl -#undef htonl -#define ntohl(x) bswap32(x) -#define htonl(x) bswap32(x) - -#endif - -#if defined(bswap64) - -#undef ntohll -#undef htonll -#define ntohll(x) bswap64(x) -#define htonll(x) bswap64(x) - -#else - -#undef ntohll -#undef htonll - #if defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && defined(__BIG_ENDIAN) # define GIT_BYTE_ORDER __BYTE_ORDER @@ -145,14 +124,33 @@ static inline uint64_t git_bswap64(uint64_t x) #endif +#undef ntohl +#undef htonl +#undef ntohll +#undef htonll + #if GIT_BYTE_ORDER == GIT_BIG_ENDIAN -# define ntohll(n) (n) -# define htonll(n) (n) +# define ntohl(x) (x) +# define htonl(x) (x) +# define ntohll(x) (x) +# define htonll(x) (x) #else -# define ntohll(n) default_bswap64(n) -# define htonll(n) default_bswap64(n) -#endif +# if defined(bswap32) +# define ntohl(x) bswap32(x) +# define htonl(x) bswap32(x) +# else +# define ntohl(x) default_swab32(x) +# define htonl(x) default_swab32(x) +# endif + +# if defined(bswap64) +# define ntohll(x) bswap64(x) +# define htonll(x) bswap64(x) +# else +# define ntohll(x) default_bswap64(x) +# define htonll(x) default_bswap64(x) +# endif #endif static inline uint16_t get_be16(const void *ptr) -- 2.47.3