048fa2df92
This patch implements ffs, __ffs, fls, __fls using __builtin_* gcc functions. These header files can be used by other architectures that rely on the gcc builtins. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
17 lines
364 B
C
17 lines
364 B
C
#ifndef _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
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#define _ASM_GENERIC_BITOPS_BUILTIN_FLS_H_
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/**
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* fls - find last (most-significant) bit set
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* @x: the word to search
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*
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* This is defined the same way as ffs.
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* Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32.
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*/
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static __always_inline int fls(int x)
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{
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return x ? sizeof(x) * 8 - __builtin_clz(x) : 0;
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}
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#endif
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