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gnucash/lib/libqof/qof/qofmath128.h

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/********************************************************************
* qofmath128.h -- an 128-bit integer library *
* Copyright (C) 2004 Linas Vepstas <linas@linas.org> *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of *
* the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License*
* along with this program; if not, contact: *
* *
* Free Software Foundation Voice: +1-617-542-5942 *
* 59 Temple Place - Suite 330 Fax: +1-617-542-2652 *
* Boston, MA 02111-1307, USA gnu@gnu.org *
* *
*******************************************************************/
#ifndef QOF_MATH_128_H
#define QOF_MATH_128_H
#include <glib.h>
/** @addtogroup Math128
* Quick-n-dirty 128-bit integer math lib. Things seem to mostly
* work, and have been tested, but not comprehensively tested.
* @{
*/
typedef struct {
guint64 hi;
guint64 lo;
short isneg; /**< sign-bit -- T if number is negative */
short isbig; /**< sizeflag -- T if number won't fit in signed 64-bit */
} qofint128;
/** Return true of two numbers are equal */
inline gboolean equal128 (qofint128 a, qofint128 b);
/** Return returns 1 if a>b, -1 if b>a, 0 if a == b */
inline int cmp128 (qofint128 a, qofint128 b);
/** Shift right by one bit (i.e. divide by two) */
inline qofint128 shift128 (qofint128 x);
/** Shift left by one bit (i.e. multiply by two) */
inline qofint128 shiftleft128 (qofint128 x);
/** Increment by one */
inline qofint128 inc128 (qofint128 a);
/** Add a pair of 128-bit numbers, returning a 128-bit number */
inline qofint128 add128 (qofint128 a, qofint128 b);
/** Multiply a pair of signed 64-bit numbers,
* returning a signed 128-bit number.
*/
inline qofint128 mult128 (gint64 a, gint64 b);
/** Divide a signed 128-bit number by a signed 64-bit,
* returning a signed 128-bit number.
*/
inline qofint128 div128 (qofint128 n, gint64 d);
/** Return the remainder of a signed 128-bit number modulo
* a signed 64-bit. That is, return n%d in 128-bit math.
* I beleive that ths algo is overflow-free, but should be
* audited some more ...
*/
inline gint64 rem128 (qofint128 n, gint64 d);
/** Return the greatest common factor of two 64-bit numbers */
inline guint64 gcf64(guint64 num, guint64 denom);
/** Return the least common multiple of two 64-bit numbers. */
inline qofint128 lcm128 (guint64 a, guint64 b);
#endif
/** @} */