xref: /PHP-5.4/ext/bcmath/libbcmath/src/divmod.c (revision f200f739)
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
bc_divmod(bc_num num1,bc_num num2,bc_num * quot,bc_num * rem,int scale TSRMLS_DC)48 bc_divmod (bc_num num1, bc_num num2, bc_num *quot, bc_num *rem, int scale TSRMLS_DC)
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 TSRMLS_CC)) return -1;
56 
57   /* Calculate final scale. */
58   rscale = MAX (num1->n_scale, num2->n_scale+scale);
59   bc_init_num(&temp TSRMLS_CC);
60 
61   /* Calculate it. */
62   bc_divide (num1, num2, &temp, scale TSRMLS_CC);
63   if (quot)
64     quotient = bc_copy_num (temp);
65   bc_multiply (temp, num2, &temp, rscale TSRMLS_CC);
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
bc_modulo(bc_num num1,bc_num num2,bc_num * result,int scale TSRMLS_DC)83 bc_modulo (bc_num num1, bc_num num2, bc_num *result, int scale TSRMLS_DC)
84 {
85   return bc_divmod (num1, num2, NULL, result, scale TSRMLS_CC);
86 }
87 
88