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Message-ID: <20140331091325.GA3814@gmail.com>
Date: Mon, 31 Mar 2014 11:13:25 +0200
From: Ingo Molnar <mingo@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org,
Peter Zijlstra <a.p.zijlstra@...llo.nl>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [GIT PULL] core/types change for v3.15
Linus,
Please pull the latest core-types-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core-types-for-linus
# HEAD: c32fa99f0b4252633aa464e28d1cb925bd2a79df bitops: Fix signedness of compile-time hweight implementations
This lone commit makes sure that __const_hweight8() is unsigned, which
addresses a build warning if code is built with -Wsign-compare.
I hope the type cast in this cleanup is fine - another option would be
to eliminate the double unary negation and use a construct with more
obvious integer type characteristics, along the lines of:
((w) & (1ULL << 1) ? 1U : 0U)
or so.
Thanks,
Ingo
------------------>
Paul Walmsley (1):
bitops: Fix signedness of compile-time hweight implementations
include/asm-generic/bitops/const_hweight.h | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/include/asm-generic/bitops/const_hweight.h b/include/asm-generic/bitops/const_hweight.h
index fa2a50b..0a7e066 100644
--- a/include/asm-generic/bitops/const_hweight.h
+++ b/include/asm-generic/bitops/const_hweight.h
@@ -5,14 +5,15 @@
* Compile time versions of __arch_hweightN()
*/
#define __const_hweight8(w) \
- ( (!!((w) & (1ULL << 0))) + \
- (!!((w) & (1ULL << 1))) + \
- (!!((w) & (1ULL << 2))) + \
- (!!((w) & (1ULL << 3))) + \
- (!!((w) & (1ULL << 4))) + \
- (!!((w) & (1ULL << 5))) + \
- (!!((w) & (1ULL << 6))) + \
- (!!((w) & (1ULL << 7))) )
+ ((unsigned int) \
+ ((!!((w) & (1ULL << 0))) + \
+ (!!((w) & (1ULL << 1))) + \
+ (!!((w) & (1ULL << 2))) + \
+ (!!((w) & (1ULL << 3))) + \
+ (!!((w) & (1ULL << 4))) + \
+ (!!((w) & (1ULL << 5))) + \
+ (!!((w) & (1ULL << 6))) + \
+ (!!((w) & (1ULL << 7)))))
#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 ))
#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
--
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