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Annotation of OpenXM_contrib/gmp/mpz/hamdist.c, Revision 1.1

1.1     ! maekawa     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.
        !             5:
        !             6: Copyright (C) 1994, 1996 Free Software Foundation, Inc.
        !             7:
        !             8: This file is part of the GNU MP Library.
        !             9:
        !            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.
        !            14:
        !            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.
        !            19:
        !            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. */
        !            24:
        !            25: #include "gmp.h"
        !            26: #include "gmp-impl.h"
        !            27:
        !            28: unsigned long int
        !            29: #if __STDC__
        !            30: mpz_hamdist (mpz_srcptr u, mpz_srcptr v)
        !            31: #else
        !            32: mpz_hamdist (u, v)
        !            33:      mpz_srcptr u;
        !            34:      mpz_srcptr v;
        !            35: #endif
        !            36: {
        !            37:   mp_srcptr up, vp;
        !            38:   mp_size_t usize, vsize, size;
        !            39:   unsigned long int count;
        !            40:
        !            41:   usize = u->_mp_size;
        !            42:   vsize = v->_mp_size;
        !            43:
        !            44:   if ((usize | vsize) < 0)
        !            45:     return ~ (unsigned long int) 0;
        !            46:
        !            47:   up = u->_mp_d;
        !            48:   vp = v->_mp_d;
        !            49:
        !            50:   if (usize > vsize)
        !            51:     {
        !            52:       count = mpn_popcount (up + vsize, usize - vsize);
        !            53:       size = vsize;
        !            54:     }
        !            55:   else
        !            56:     {
        !            57:       count = mpn_popcount (vp + usize, vsize - usize);
        !            58:       size = usize;
        !            59:     }
        !            60:
        !            61:   return count + mpn_hamdist (up, vp, size);
        !            62: }