From: H. Peter Anvin <hpa@zytor.com>
Date: Wed, 30 Apr 2014 21:22:19 +0000 (-0700)
Subject: word-at-a-time: simplify big-endian zero_bytemask macro
X-Git-Tag: firefly_0821_release~176^2~3973
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=789ce9dca8007ab5d7c72b9a174a29243817ac32;p=firefly-linux-kernel-4.4.55.git

word-at-a-time: simplify big-endian zero_bytemask macro

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>
---

diff --git a/include/asm-generic/word-at-a-time.h b/include/asm-generic/word-at-a-time.h
index d96deb443f18..94f9ea8abcae 100644
--- a/include/asm-generic/word-at-a-time.h
+++ b/include/asm-generic/word-at-a-time.h
@@ -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 */