66 lines
1.3 KiB
C
66 lines
1.3 KiB
C
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/*
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* lib/clz_ctz.c
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*
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* Copyright (C) 2013 Chanho Min <chanho.min@lge.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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* The functions in this file aren't called directly, but are required by
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* GCC builtins such as __builtin_ctz, and therefore they can't be removed
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* despite appearing unreferenced in kernel source.
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*
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* __c[lt]z[sd]i2 can be overridden by linking arch-specific versions.
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*/
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#include <linux/export.h>
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#include <linux/kernel.h>
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int __weak __ctzsi2(int val);
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int __weak __ctzsi2(int val)
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{
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return __ffs(val);
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}
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EXPORT_SYMBOL(__ctzsi2);
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int __weak __clzsi2(int val);
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int __weak __clzsi2(int val)
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{
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return 32 - fls(val);
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}
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EXPORT_SYMBOL(__clzsi2);
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int __weak __clzdi2(long val);
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int __weak __ctzdi2(long val);
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#if BITS_PER_LONG == 32
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int __weak __clzdi2(long val)
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{
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return 32 - fls((int)val);
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}
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EXPORT_SYMBOL(__clzdi2);
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int __weak __ctzdi2(long val)
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{
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return __ffs((u32)val);
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}
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EXPORT_SYMBOL(__ctzdi2);
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#elif BITS_PER_LONG == 64
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int __weak __clzdi2(long val)
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{
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return 64 - fls64((u64)val);
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}
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EXPORT_SYMBOL(__clzdi2);
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int __weak __ctzdi2(long val)
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{
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return __ffs64((u64)val);
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}
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EXPORT_SYMBOL(__ctzdi2);
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#else
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#error BITS_PER_LONG not 32 or 64
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#endif
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