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 __ctzsi2(int val)
19{
20	return __ffs(val);
21}
22EXPORT_SYMBOL(__ctzsi2);
23
24int __weak __clzsi2(int val);
25int __weak __clzsi2(int val)
26{
27	return 32 - fls(val);
28}
29EXPORT_SYMBOL(__clzsi2);
30
31int __weak __clzdi2(long val);
32int __weak __ctzdi2(long val);
33#if BITS_PER_LONG == 32
34
35int __weak __clzdi2(long val)
36{
37	return 32 - fls((int)val);
38}
39EXPORT_SYMBOL(__clzdi2);
40
41int __weak __ctzdi2(long val)
42{
43	return __ffs((u32)val);
44}
45EXPORT_SYMBOL(__ctzdi2);
46
47#elif BITS_PER_LONG == 64
48
49int __weak __clzdi2(long val)
50{
51	return 64 - fls64((u64)val);
52}
53EXPORT_SYMBOL(__clzdi2);
54
55int __weak __ctzdi2(long val)
56{
57	return __ffs64((u64)val);
58}
59EXPORT_SYMBOL(__ctzdi2);
60
61#else
62#error BITS_PER_LONG not 32 or 64
63#endif

 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 __ctzsi2(int val)
19{
20	return __ffs(val);
21}
22EXPORT_SYMBOL(__ctzsi2);
23
24int __weak __clzsi2(int val);
25int __weak __clzsi2(int val)
26{
27	return 32 - fls(val);
28}
29EXPORT_SYMBOL(__clzsi2);
30
31int __weak __clzdi2(long val);
32int __weak __ctzdi2(long val);
33#if BITS_PER_LONG == 32
34
35int __weak __clzdi2(long val)
36{
37	return 32 - fls((int)val);
38}
39EXPORT_SYMBOL(__clzdi2);
40
41int __weak __ctzdi2(long val)
42{
43	return __ffs((u32)val);
44}
45EXPORT_SYMBOL(__ctzdi2);
46
47#elif BITS_PER_LONG == 64
48
49int __weak __clzdi2(long val)
50{
51	return 64 - fls64((u64)val);
52}
53EXPORT_SYMBOL(__clzdi2);
54
55int __weak __ctzdi2(long val)
56{
57	return __ffs64((u64)val);
58}
59EXPORT_SYMBOL(__ctzdi2);
60
61#else
62#error BITS_PER_LONG not 32 or 64
63#endif