1 /*
2  * lib/clz_ctz.c
3  *
4  * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  * The functions in this file aren't called directly, but are required by
10  * GCC builtins such as __builtin_ctz, and therefore they can't be removed
11  * despite appearing unreferenced in kernel source.
12  *
13  * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
14  */
15 
16 #include <linux/export.h>
17 #include <linux/kernel.h>
18 
19 int __weak __ctzsi2(int val);
__ctzsi2(int val)20 int __weak __ctzsi2(int val)
21 {
22 	return __ffs(val);
23 }
24 EXPORT_SYMBOL(__ctzsi2);
25 
26 int __weak __clzsi2(int val);
__clzsi2(int val)27 int __weak __clzsi2(int val)
28 {
29 	return 32 - fls(val);
30 }
31 EXPORT_SYMBOL(__clzsi2);
32 
33 int __weak __clzdi2(u64 val);
__clzdi2(u64 val)34 int __weak __clzdi2(u64 val)
35 {
36 	return 64 - fls64(val);
37 }
38 EXPORT_SYMBOL(__clzdi2);
39 
40 int __weak __ctzdi2(u64 val);
__ctzdi2(u64 val)41 int __weak __ctzdi2(u64 val)
42 {
43 	return __ffs64(val);
44 }
45 EXPORT_SYMBOL(__ctzdi2);
46