[linux-block.git] / lib / clz_ctz.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * lib/clz_ctz.c
 *
 * Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
 *
 * The functions in this file aren't called directly, but are required by
 * GCC builtins such as __builtin_ctz, and therefore they can't be removed
 * despite appearing unreferenced in kernel source.
 *
 * __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
 */

#include <linux/export.h>
#include <linux/kernel.h>

int __weak __ctzsi2(int val);
int __weak __ctzsi2(int val)
{
	return __ffs(val);
}
EXPORT_SYMBOL(__ctzsi2);

int __weak __clzsi2(int val);
int __weak __clzsi2(int val)
{
	return 32 - fls(val);
}
EXPORT_SYMBOL(__clzsi2);

int __weak __clzdi2(long val);
int __weak __ctzdi2(long val);
#if BITS_PER_LONG == 32

int __weak __clzdi2(long val)
{
	return 32 - fls((int)val);
}
EXPORT_SYMBOL(__clzdi2);

int __weak __ctzdi2(long val)
{
	return __ffs((u32)val);
}
EXPORT_SYMBOL(__ctzdi2);

#elif BITS_PER_LONG == 64

int __weak __clzdi2(long val)
{
	return 64 - fls64((u64)val);
}
EXPORT_SYMBOL(__clzdi2);

int __weak __ctzdi2(long val)
{
	return __ffs64((u64)val);
}
EXPORT_SYMBOL(__ctzdi2);

#else
#error BITS_PER_LONG not 32 or 64
#endif
Commit	Line	Data
	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(long val);
	32	int __weak __ctzdi2(long val);
	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