Commit 3b88da4a authored by Joshua Clayton's avatar Joshua Clayton Committed by Greg Kroah-Hartman

lib: add bitrev8x4()

Add a function to reverse bytes within a 32 bit word.
Operate on a u32 rather than individual bytes.
Signed-off-by: default avatarJoshua Clayton <stillcompiling@gmail.com>
Signed-off-by: default avatarAlan Tull <atull@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 60acfa59
......@@ -29,6 +29,8 @@ static inline u32 __bitrev32(u32 x)
#endif /* CONFIG_HAVE_ARCH_BITREVERSE */
#define __bitrev8x4(x) (__bitrev32(swab32(x)))
#define __constant_bitrev32(x) \
({ \
u32 __x = x; \
......@@ -50,6 +52,15 @@ static inline u32 __bitrev32(u32 x)
__x; \
})
#define __constant_bitrev8x4(x) \
({ \
u32 __x = x; \
__x = ((__x & (u32)0xF0F0F0F0UL) >> 4) | ((__x & (u32)0x0F0F0F0FUL) << 4); \
__x = ((__x & (u32)0xCCCCCCCCUL) >> 2) | ((__x & (u32)0x33333333UL) << 2); \
__x = ((__x & (u32)0xAAAAAAAAUL) >> 1) | ((__x & (u32)0x55555555UL) << 1); \
__x; \
})
#define __constant_bitrev8(x) \
({ \
u8 __x = x; \
......@@ -75,6 +86,14 @@ static inline u32 __bitrev32(u32 x)
__bitrev16(__x); \
})
#define bitrev8x4(x) \
({ \
u32 __x = x; \
__builtin_constant_p(__x) ? \
__constant_bitrev8x4(__x) : \
__bitrev8x4(__x); \
})
#define bitrev8(x) \
({ \
u8 __x = x; \
......
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