word-at-a-time: simplify big-endian zero_bytemask macro
authorH. Peter Anvin <hpa@zytor.com>
Wed, 30 Apr 2014 21:22:19 +0000 (14:22 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 1 May 2014 15:57:44 +0000 (08:57 -0700)
This is simpler and cleaner.  Depending on architecture, a smart
compiler may or may not generate the same code.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/asm-generic/word-at-a-time.h

index d96deb443f18403d50e813f7a82a478e92a6d064..94f9ea8abcae35af8ca36560403fbd25facb7c65 100644 (file)
@@ -50,7 +50,7 @@ static inline bool has_zero(unsigned long val, unsigned long *data, const struct
 }
 
 #ifndef zero_bytemask
-#define zero_bytemask(mask) (~0ul << __fls(mask) << 1)
+#define zero_bytemask(mask) (~1ul << __fls(mask))
 #endif
 
 #endif /* _ASM_WORD_AT_A_TIME_H */