1527bc8b92
Rename the extisting runtime hweight() implementations to __arch_hweight(), rename the compile-time versions to __const_hweight() and then have hweight() pick between them. Suggested-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20100318111929.GB11152@aftab> Acked-by: H. Peter Anvin <hpa@zytor.com> LKML-Reference: <1265028224.24455.154.camel@laptop> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
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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( (!!((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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