On Thu, Jun 09, 2022 at 10:29:33AM -0700, Andrew Morton wrote:
> A cast inside __builtin_constant_p doesn't do anything since it should
> evaluate as constant at compile time irrespective of this cast. Instead,
> I moved this cast outside the ternary to ensure the return type is as
> expected.
> --- a/include/uapi/linux/swab.h~include-uapi-linux-swabh-move-explicit-cast-outside-ternary
> +++ a/include/uapi/linux/swab.h
> @@ -102,7 +102,7 @@ static inline __attribute_const__ __u32
> #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
> #else
> #define __swab16(x) \
> - (__builtin_constant_p((__u16)(x)) ? \
> + (__u16)(__builtin_constant_p(x) ? \
This cast is necessary.
> ___constant_swab16(x) : \
> __fswab16(x))
> #endif
> @@ -115,7 +115,7 @@ static inline __attribute_const__ __u32
> #define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
> #else
> #define __swab32(x) \
> - (__builtin_constant_p((__u32)(x)) ? \
> + (__u32)(__builtin_constant_p(x) ? \
> ___constant_swab32(x) : \
> __fswab32(x))
> #endif
> @@ -128,7 +128,7 @@ static inline __attribute_const__ __u32
> #define __swab64(x) (__u64)__builtin_bswap64((__u64)(x))
> #else
> #define __swab64(x) \
> - (__builtin_constant_p((__u64)(x)) ? \
> + (__u64)(__builtin_constant_p(x) ? \
> ___constant_swab64(x) : \
> __fswab64(x))
These two aren't? typeof(c ? u32 : u32) is u32.