redonkable/alistair23-linux
redonkable/alistair23-linux
1
0
Fork 0
Code Releases Activity

Merge branch 'core-types-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Browse source 
Pull hweight type fix from Ingo Molnar:
 "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"

* 'core-types-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  bitops: Fix signedness of compile-time hweight implementations
This commit is contained in:
Linus Torvalds 2014-03-31 11:09:09 -07:00
parent b3fd4ea9df c32fa99f0b
commit d31605dc8a
1 changed files with 9 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

17
include/asm-generic/bitops/const_hweight.h
View file

@ -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))