swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
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Tip revision: 46cf053efec6a3a5f343fead837777efe8252a46 authored by Linus Torvalds on 23 December 2019, 01:02:23 UTC
Linux 5.5-rc3
Tip revision: 46cf053
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
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