1 /* mpz_hamdist(mpz_ptr op1, mpz_ptr op2) -- Compute the hamming distance
2 between OP1 and OP2. If one of the operands is negative, return ~0. (We
3 could make the function well-defined when both operands are negative, but
4 that would probably not be worth the trouble.
6 Copyright (C) 1994, 1996 Free Software Foundation, Inc.
8 This file is part of the GNU MP Library.
10 The GNU MP Library is free software; you can redistribute it and/or modify
11 it under the terms of the GNU Library General Public License as published by
12 the Free Software Foundation; either version 2 of the License, or (at your
13 option) any later version.
15 The GNU MP Library is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
18 License for more details.
20 You should have received a copy of the GNU Library General Public License
21 along with the GNU MP Library; see the file COPYING.LIB. If not, write to
22 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
23 MA 02111-1307, USA. */
30 mpz_hamdist (mpz_srcptr u, mpz_srcptr v)
38 mp_size_t usize, vsize, size;
39 unsigned long int count;
44 if ((usize | vsize) < 0)
45 return ~ (unsigned long int) 0;
52 count = mpn_popcount (up + vsize, usize - vsize);
57 count = mpn_popcount (vp + usize, vsize - usize);
61 return count + mpn_hamdist (up, vp, size);