mirror of https://github.com/bsnes-emu/bsnes.git
55 lines
2.1 KiB
C++
Executable File
55 lines
2.1 KiB
C++
Executable File
/***************************************************************************
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* Copyright (C) 2008 by Sindre Aamås *
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* aamas@stud.ntnu.no *
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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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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License version 2 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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* version 2 along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
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***************************************************************************/
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#include "u48div.h"
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unsigned long u48div(unsigned long num1, unsigned num2, const unsigned long den) {
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unsigned long res = 0;
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unsigned s = 16;
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do {
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if (num1 < 0x10000) {
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num1 <<= s;
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num1 |= num2 & ((1 << s) - 1);
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s = 0;
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} else {
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if (num1 < 0x1000000) {
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const unsigned maxs = s < 8 ? s : 8;
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num1 <<= maxs;
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num1 |= (num2 >> (s -= maxs)) & ((1 << maxs) - 1);
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}
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if (num1 < 0x10000000) {
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const unsigned maxs = s < 4 ? s : 4;
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num1 <<= maxs;
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num1 |= (num2 >> (s -= maxs)) & ((1 << maxs) - 1);
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}
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while (num1 < den && s) {
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num1 <<= 1; // if this overflows we're screwed
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num1 |= num2 >> --s & 1;
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}
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}
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res += (num1 / den) << s;
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num1 = (num1 % den);
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} while (s);
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return res;
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}
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