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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4df87bb7 CM |
2 | /* |
3 | * lib/clz_ctz.c | |
4 | * | |
5 | * Copyright (C) 2013 Chanho Min <[email protected]> | |
6 | * | |
3c516cdd RK |
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. | |
4df87bb7 CM |
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 | ||
3c516cdd | 17 | int __weak __ctzsi2(int val); |
4df87bb7 CM |
18 | int __weak __ctzsi2(int val) |
19 | { | |
20 | return __ffs(val); | |
21 | } | |
22 | EXPORT_SYMBOL(__ctzsi2); | |
23 | ||
3c516cdd | 24 | int __weak __clzsi2(int val); |
4df87bb7 CM |
25 | int __weak __clzsi2(int val) |
26 | { | |
27 | return 32 - fls(val); | |
28 | } | |
29 | EXPORT_SYMBOL(__clzsi2); | |
30 | ||
3c516cdd RK |
31 | int __weak __clzdi2(long val); |
32 | int __weak __ctzdi2(long val); | |
4df87bb7 CM |
33 | #if BITS_PER_LONG == 32 |
34 | ||
35 | int __weak __clzdi2(long val) | |
36 | { | |
37 | return 32 - fls((int)val); | |
38 | } | |
39 | EXPORT_SYMBOL(__clzdi2); | |
40 | ||
41 | int __weak __ctzdi2(long val) | |
42 | { | |
43 | return __ffs((u32)val); | |
44 | } | |
45 | EXPORT_SYMBOL(__ctzdi2); | |
46 | ||
47 | #elif BITS_PER_LONG == 64 | |
48 | ||
49 | int __weak __clzdi2(long val) | |
50 | { | |
51 | return 64 - fls64((u64)val); | |
52 | } | |
53 | EXPORT_SYMBOL(__clzdi2); | |
54 | ||
55 | int __weak __ctzdi2(long val) | |
56 | { | |
57 | return __ffs64((u64)val); | |
58 | } | |
59 | EXPORT_SYMBOL(__ctzdi2); | |
60 | ||
61 | #else | |
62 | #error BITS_PER_LONG not 32 or 64 | |
63 | #endif |