1 /* divmod.c: bcmath library file. */
2 /*
3 Copyright (C) 1991, 1992, 1993, 1994, 1997 Free Software Foundation, Inc.
4 Copyright (C) 2000 Philip A. Nelson
5
6 This library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2 of the License, or (at your option) any later version.
10
11 This library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details. (COPYING.LIB)
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with this library; if not, write to:
18
19 The Free Software Foundation, Inc.
20 59 Temple Place, Suite 330
21 Boston, MA 02111-1307 USA.
22
23 You may contact the author by:
24 e-mail: philnelson@acm.org
25 us-mail: Philip A. Nelson
26 Computer Science Department, 9062
27 Western Washington University
28 Bellingham, WA 98226-9062
29
30 *************************************************************************/
31
32 #include <config.h>
33 #include <stdio.h>
34 #include <assert.h>
35 #include <stdlib.h>
36 #include <ctype.h>
37 #include <stdarg.h>
38 #include "bcmath.h"
39 #include "private.h"
40
41
42 /* Division *and* modulo for numbers. This computes both NUM1 / NUM2 and
43 NUM1 % NUM2 and puts the results in QUOT and REM, except that if QUOT
44 is NULL then that store will be omitted.
45 */
46
47 int
48 bc_divmod (bc_num num1, bc_num num2, bc_num *quot, bc_num *rem, int scale)
49 {
50 bc_num quotient = NULL;
51 bc_num temp;
52 int rscale;
53
54 /* Check for correct numbers. */
55 if (bc_is_zero (num2)) return -1;
56
57 /* Calculate final scale. */
58 rscale = MAX (num1->n_scale, num2->n_scale+scale);
59 bc_init_num(&temp);
60
61 /* Calculate it. */
62 bc_divide (num1, num2, &temp, scale);
63 if (quot)
64 quotient = bc_copy_num (temp);
65 bc_multiply (temp, num2, &temp, rscale);
66 bc_sub (num1, temp, rem, rscale);
67 bc_free_num (&temp);
68
69 if (quot)
70 {
71 bc_free_num (quot);
72 *quot = quotient;
73 }
74
75 return 0; /* Everything is OK. */
76 }
77
78
79 /* Modulo for numbers. This computes NUM1 % NUM2 and puts the
80 result in RESULT. */
81
82 int
83 bc_modulo (bc_num num1, bc_num num2, bc_num *result, int scale)
84 {
85 return bc_divmod (num1, num2, NULL, result, scale);
86 }
87