xref: /PHP-5.6/ext/bcmath/libbcmath/src/zero.c (revision f200f739)
1 /* zero.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 /* In some places we need to check if the number NUM is zero. */
42 
43 char
bc_is_zero(bc_num num TSRMLS_DC)44 bc_is_zero (bc_num num TSRMLS_DC)
45 {
46   int  count;
47   char *nptr;
48 
49   /* Quick check. */
50   if (num == BCG(_zero_)) return TRUE;
51 
52   /* Initialize */
53   count = num->n_len + num->n_scale;
54   nptr = num->n_value;
55 
56   /* The check */
57   while ((count > 0) && (*nptr++ == 0)) count--;
58 
59   if (count != 0)
60     return FALSE;
61   else
62     return TRUE;
63 }
64 
65