blob: 2e11e48446abf1bf078163575e10a33a8028febc
| 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); |
| 20 | int __weak __ctzsi2(int val) |
| 21 | { |
| 22 | return __ffs(val); |
| 23 | } |
| 24 | EXPORT_SYMBOL(__ctzsi2); |
| 25 | |
| 26 | int __weak __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(long val); |
| 34 | int __weak __ctzdi2(long val); |
| 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 |
| 66 |