forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
45 lines
844 B
45 lines
844 B
/* SPDX-License-Identifier: GPL-2.0 */ |
|
#ifndef _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ |
|
#define _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ |
|
|
|
#include <asm/types.h> |
|
#include <asm/bitsperlong.h> |
|
|
|
/** |
|
* __ffs - find first bit in word. |
|
* @word: The word to search |
|
* |
|
* Undefined if no bit exists, so code should check against 0 first. |
|
*/ |
|
static __always_inline unsigned long __ffs(unsigned long word) |
|
{ |
|
int num = 0; |
|
|
|
#if __BITS_PER_LONG == 64 |
|
if ((word & 0xffffffff) == 0) { |
|
num += 32; |
|
word >>= 32; |
|
} |
|
#endif |
|
if ((word & 0xffff) == 0) { |
|
num += 16; |
|
word >>= 16; |
|
} |
|
if ((word & 0xff) == 0) { |
|
num += 8; |
|
word >>= 8; |
|
} |
|
if ((word & 0xf) == 0) { |
|
num += 4; |
|
word >>= 4; |
|
} |
|
if ((word & 0x3) == 0) { |
|
num += 2; |
|
word >>= 2; |
|
} |
|
if ((word & 0x1) == 0) |
|
num += 1; |
|
return num; |
|
} |
|
|
|
#endif /* _TOOLS_LINUX_ASM_GENERIC_BITOPS___FFS_H_ */
|
|
|