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authorPaul Walmsley <pwalmsley@nvidia.com>2013-12-18 05:02:14 -0800
committerIngo Molnar <mingo@kernel.org>2014-02-09 13:39:26 +0100
commitc32fa99f0b4252633aa464e28d1cb925bd2a79df (patch)
tree3f857effbb10d28785fa4d4cc8d0f2fbe1c1e7ba /include/asm-generic
parent494479038d97f1b9f76fc633a360a681acdf035c (diff)
bitops: Fix signedness of compile-time hweight implementations
Enabling '-Wsign-compare' compiler warnings on code that includes include/linux/bitops.h can generate the following warning: In file included from include/linux/kernel.h:10:0, from <random filename>:48: include/linux/bitops.h: In function 'hweight_long': include/linux/bitops.h:77:26: error: signed and unsigned type in conditional expression [-Werror=sign-compare] (converted to an error with -Werror) This is due to the use of the logical negation operator '!' in the __const_hweight8 macro in include/asm-generic/bitops/const_hweight.h. The use of that operator here results in a signed value. Fix by explicitly casting the __const_hweight8 macro expansion to 'unsigned int'. While here, clean up several checkpatch.pl warnings. Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1312180459580.30198@tamien Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/asm-generic')
-rw-r--r--include/asm-generic/bitops/const_hweight.h17
1 files changed, 9 insertions, 8 deletions
diff --git a/include/asm-generic/bitops/const_hweight.h b/include/asm-generic/bitops/const_hweight.h
index fa2a50b7ee66..0a7e06623470 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))