/*
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* Copyright © 2005 Gilles Chanteperdrix.
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*
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* Xenomai is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* Xenomai is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Xenomai; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
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* 02111-1307, USA.
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*/
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#include <linux/module.h>
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/**
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* @ingroup cobalt_core
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* @defgroup cobalt_core_arith In-kernel arithmetics
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*
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* A collection of helpers performing arithmetics not implicitly
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* available from kernel context via GCC helpers. Many of these
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* routines enable 64bit arithmetics on 32bit systems. Xenomai
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* architecture ports normally implement the performance critical ones
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* in hand-crafted assembly code (see
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* kernel/cobalt/arch/\<arch\>/include/asm/xenomai/uapi/arith.h).
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* @{
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*/
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/**
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* Architecture-independent div64 operation with remainder.
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*
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* @param a dividend
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*
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* @param b divisor
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*
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* @param rem if non-NULL, a pointer to a 64bit variable for
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* collecting the remainder from the division.
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*/
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unsigned long long xnarch_generic_full_divmod64(unsigned long long a,
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unsigned long long b,
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unsigned long long *rem)
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{
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unsigned long long q = 0, r = a;
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int i;
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for (i = fls(a >> 32) - fls(b >> 32), b <<= i; i >= 0; i--, b >>= 1) {
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q <<= 1;
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if (b <= r) {
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r -= b;
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q++;
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}
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}
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if (rem)
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*rem = r;
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return q;
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}
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EXPORT_SYMBOL_GPL(xnarch_generic_full_divmod64);
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/** @} */
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