| Message ID | 1402601042-15487-1-git-send-email-tim.gardner@canonical.com |
|---|---|
| State | New |
| Headers | show |
On 06/12/2014 12:24 PM, Tim Gardner wrote: > From: Paul Walmsley <pwalmsley@nvidia.com> > > BugLink: http://bugs.launchpad.net/bugs/1321791 > > 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> > (cherry picked from commit c32fa99f0b4252633aa464e28d1cb925bd2a79df) > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> > --- > 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)) >
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))