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 17 int __weak __ctzsi2(int val); 18 int __weak __ctzsi2(int val) 19 { 20 return __ffs(val); 21 } 22 EXPORT_SYMBOL(__ctzsi2); 23 24 int __weak __clzsi2(int val); 25 int __weak __clzsi2(int val) 26 { 27 return 32 - fls(val); 28 } 29 EXPORT_SYMBOL(__clzsi2); 30 31 int __weak __clzdi2(u64 val); 32 int __weak __clzdi2(u64 val) 33 { 34 return 64 - fls64(val); 35 } 36 EXPORT_SYMBOL(__clzdi2); 37 38 int __weak __ctzdi2(u64 val); 39 int __weak __ctzdi2(u64 val) 40 { 41 return __ffs64(val); 42 } 43 EXPORT_SYMBOL(__ctzdi2); 44