lkml.org 
[lkml]   [2014]   [Mar]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
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))

\
 
 \ /
  Last update: 2014-03-31 12:01    [W:0.029 / U:0.888 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site