c32fa99f0b
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>
43 lines
1.6 KiB
C
43 lines
1.6 KiB
C
#ifndef _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
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#define _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_
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/*
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* Compile time versions of __arch_hweightN()
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*/
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#define __const_hweight8(w) \
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((unsigned int) \
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((!!((w) & (1ULL << 0))) + \
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(!!((w) & (1ULL << 1))) + \
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(!!((w) & (1ULL << 2))) + \
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(!!((w) & (1ULL << 3))) + \
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(!!((w) & (1ULL << 4))) + \
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(!!((w) & (1ULL << 5))) + \
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(!!((w) & (1ULL << 6))) + \
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(!!((w) & (1ULL << 7)))))
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#define __const_hweight16(w) (__const_hweight8(w) + __const_hweight8((w) >> 8 ))
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#define __const_hweight32(w) (__const_hweight16(w) + __const_hweight16((w) >> 16))
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#define __const_hweight64(w) (__const_hweight32(w) + __const_hweight32((w) >> 32))
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/*
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* Generic interface.
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*/
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#define hweight8(w) (__builtin_constant_p(w) ? __const_hweight8(w) : __arch_hweight8(w))
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#define hweight16(w) (__builtin_constant_p(w) ? __const_hweight16(w) : __arch_hweight16(w))
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#define hweight32(w) (__builtin_constant_p(w) ? __const_hweight32(w) : __arch_hweight32(w))
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#define hweight64(w) (__builtin_constant_p(w) ? __const_hweight64(w) : __arch_hweight64(w))
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/*
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* Interface for known constant arguments
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*/
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#define HWEIGHT8(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight8(w))
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#define HWEIGHT16(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight16(w))
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#define HWEIGHT32(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight32(w))
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#define HWEIGHT64(w) (BUILD_BUG_ON_ZERO(!__builtin_constant_p(w)) + __const_hweight64(w))
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/*
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* Type invariant interface to the compile time constant hweight functions.
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*/
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#define HWEIGHT(w) HWEIGHT64((u64)w)
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#endif /* _ASM_GENERIC_BITOPS_CONST_HWEIGHT_H_ */
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