[PATCH] Cygwin: define byteswap.h inlines as macros

Corinna Vinschen corinna-cygwin@cygwin.com
Tue Mar 15 09:03:00 GMT 2016


On Mar 14 22:13, Yaakov Selkowitz wrote:
> The bswap_* "functions" are macros in glibc, so they may be tested for
> by the preprocessor (e.g. #ifdef bswap_16).
> 
> Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com>
> ---
>  winsup/cygwin/include/byteswap.h | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/winsup/cygwin/include/byteswap.h b/winsup/cygwin/include/byteswap.h
> index cd5a726..9f73c5a 100644
> --- a/winsup/cygwin/include/byteswap.h
> +++ b/winsup/cygwin/include/byteswap.h
> @@ -16,23 +16,27 @@ extern "C" {
>  #endif
>  
>  static __inline unsigned short
> -bswap_16 (unsigned short __x)
> +__bswap_16 (unsigned short __x)
>  {
>    return (__x >> 8) | (__x << 8);
>  }
>  
>  static __inline unsigned int
> -bswap_32 (unsigned int __x)
> +__bswap_32 (unsigned int __x)
>  {
> -  return (bswap_16 (__x & 0xffff) << 16) | (bswap_16 (__x >> 16));
> +  return (__bswap_16 (__x & 0xffff) << 16) | (__bswap_16 (__x >> 16));
>  }
>  
>  static __inline unsigned long long
> -bswap_64 (unsigned long long __x)
> +__bswap_64 (unsigned long long __x)
>  {
> -  return (((unsigned long long) bswap_32 (__x & 0xffffffffull)) << 32) | (bswap_32 (__x >> 32));
> +  return (((unsigned long long) __bswap_32 (__x & 0xffffffffull)) << 32) | (__bswap_32 (__x >> 32));
>  }
>  
> +#define bswap_16(x) __bswap_16(x)
> +#define bswap_32(x) __bswap_32(x)
> +#define bswap_64(x) __bswap_64(x)
> +
>  #ifdef __cplusplus
>  }
>  #endif
> -- 
> 2.7.0

ACK.

While we're at it, what about converting the types to implicit types
(__uint16_t, __uint32_t, __uint64_t).  Also, do we want to convert the
inline code to use the x86 bswap instructions?


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat
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