1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * lib/clz_ctz.c
4 *
5 * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
6 *
7 * The functions in this file aren't called directly, but are required by
8 * GCC builtins such as __builtin_ctz, and therefore they can't be removed
9 * despite appearing unreferenced in kernel source.
10 *
11 * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
12 */
13
14#include <linux/export.h>
15#include <linux/kernel.h>
16
17int __weak __ctzsi2(int val);
18int __weak __attribute_const__ __ctzsi2(int val)
19{
20 return __ffs(val);
21}
22EXPORT_SYMBOL(__ctzsi2);
23
24int __weak __clzsi2(int val);
25int __weak __attribute_const__ __clzsi2(int val)
26{
27 return 32 - fls(x: val);
28}
29EXPORT_SYMBOL(__clzsi2);
30
31int __weak __clzdi2(u64 val);
32int __weak __attribute_const__ __clzdi2(u64 val)
33{
34 return 64 - fls64(x: val);
35}
36EXPORT_SYMBOL(__clzdi2);
37
38int __weak __ctzdi2(u64 val);
39int __weak __attribute_const__ __ctzdi2(u64 val)
40{
41 return __ffs64(word: val);
42}
43EXPORT_SYMBOL(__ctzdi2);
44