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