xref: /plan9/sys/src/ape/cmd/diff/cmpbuf.c (revision 0b459c2cb92b7c9d88818e9a2f72e678e5bc4553)
1 /* Buffer primitives for comparison operations.
2    Copyright (C) 1993 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 2, or (at your option)
7    any later version.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, write to the Free Software
16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
17 
18 #include "system.h"
19 #include "cmpbuf.h"
20 
21 /* Least common multiple of two buffer sizes A and B.  */
22 
23 size_t
buffer_lcm(a,b)24 buffer_lcm (a, b)
25      size_t a, b;
26 {
27   size_t m, n, r;
28 
29   /* Yield reasonable values if buffer sizes are zero.  */
30   if (!a)
31     return b ? b : 8 * 1024;
32   if (!b)
33     return a;
34 
35   /* n = gcd (a, b) */
36   for (m = a, n = b;  (r = m % n) != 0;  m = n, n = r)
37     continue;
38 
39   return a/n * b;
40 }
41