diff options
Diffstat (limited to 'arch/nios2/include/asm/bitops/ffs.h')
| -rw-r--r-- | arch/nios2/include/asm/bitops/ffs.h | 41 | 
1 files changed, 41 insertions, 0 deletions
| diff --git a/arch/nios2/include/asm/bitops/ffs.h b/arch/nios2/include/asm/bitops/ffs.h new file mode 100644 index 000000000..fbbb43af7 --- /dev/null +++ b/arch/nios2/include/asm/bitops/ffs.h @@ -0,0 +1,41 @@ +#ifndef _ASM_GENERIC_BITOPS_FFS_H_ +#define _ASM_GENERIC_BITOPS_FFS_H_ + +/** + * ffs - find first bit set + * @x: the word to search + * + * This is defined the same way as + * the libc and compiler builtin ffs routines, therefore + * differs in spirit from the above ffz (man ffs). + */ +static inline int ffs(int x) +{ +	int r = 1; + +	if (!x) +		return 0; +	if (!(x & 0xffff)) { +		x >>= 16; +		r += 16; +	} +	if (!(x & 0xff)) { +		x >>= 8; +		r += 8; +	} +	if (!(x & 0xf)) { +		x >>= 4; +		r += 4; +	} +	if (!(x & 3)) { +		x >>= 2; +		r += 2; +	} +	if (!(x & 1)) { +		x >>= 1; +		r += 1; +	} +	return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FFS_H_ */ |