diff options
| author | Paul Walmsley <pwalmsley@nvidia.com> | 2013-12-18 08:02:14 -0500 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-02-09 07:39:26 -0500 |
| commit | c32fa99f0b4252633aa464e28d1cb925bd2a79df (patch) | |
| tree | 3f857effbb10d28785fa4d4cc8d0f2fbe1c1e7ba /include/asm-generic/bitops/const_hweight.h | |
| parent | 494479038d97f1b9f76fc633a360a681acdf035c (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/bitops/const_hweight.h')
| -rw-r--r-- | include/asm-generic/bitops/const_hweight.h | 17 |
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 @@ | |||
| 5 | * Compile time versions of __arch_hweightN() | 5 | * Compile time versions of __arch_hweightN() |
| 6 | */ | 6 | */ |
| 7 | #define __const_hweight8(w) \ | 7 | #define __const_hweight8(w) \ |
| 8 | ( (!!((w) & (1ULL << 0))) + \ | 8 | ((unsigned int) \ |
| 9 | (!!((w) & (1ULL << 1))) + \ | 9 | ((!!((w) & (1ULL << 0))) + \ |
| 10 | (!!((w) & (1ULL << 2))) + \ | 10 | (!!((w) & (1ULL << 1))) + \ |
| 11 | (!!((w) & (1ULL << 3))) + \ | 11 | (!!((w) & (1ULL << 2))) + \ |
| 12 | (!!((w) & (1ULL << 4))) + \ | 12 | (!!((w) & (1ULL << 3))) + \ |
| 13 | (!!((w) & (1ULL << 5))) + \ | 13 | (!!((w) & (1ULL << 4))) + \ |
| 14 | (!!((w) & (1ULL << 6))) + \ | 14 | (!!((w) & (1ULL << 5))) + \ |
| 15 | (!!((w) & (1ULL << 7))) ) | 15 | (!!((w) & (1ULL << 6))) + \ |
| 16 | (!!((w) & (1ULL << 7))))) | ||
| 16 | 17 | ||
| 17 | #define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) | 18 | #define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 )) |
| 18 | #define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) | 19 | #define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16)) |