linux-kernel - [GIT PULL] core/types change for v3.15

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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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