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); __ctzsi2(int val)20int __weak __ctzsi2(int val) 21 { 22 return __ffs(val); 23 } 24 EXPORT_SYMBOL(__ctzsi2); 25 26 int __weak __clzsi2(int val); __clzsi2(int val)27int __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 __clzdi2(long val)37int __weak __clzdi2(long val) 38 { 39 return 32 - fls((int)val); 40 } 41 EXPORT_SYMBOL(__clzdi2); 42 __ctzdi2(long val)43int __weak __ctzdi2(long val) 44 { 45 return __ffs((u32)val); 46 } 47 EXPORT_SYMBOL(__ctzdi2); 48 49 #elif BITS_PER_LONG == 64 50 __clzdi2(long val)51int __weak __clzdi2(long val) 52 { 53 return 64 - fls64((u64)val); 54 } 55 EXPORT_SYMBOL(__clzdi2); 56 __ctzdi2(long val)57int __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