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Diff for /OpenXM_contrib/gmp/mpz/Attic/invert.c between version 1.1.1.1 and 1.1.1.2

version 1.1.1.1, 2000/01/10 15:35:27 version 1.1.1.2, 2000/09/09 14:12:53
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 /* mpz_invert (inv, x, n).  Find multiplicative inverse of X in Z(N).  /* mpz_invert (inv, x, n).  Find multiplicative inverse of X in Z(N).
    If X has an inverse, return non-zero and store inverse in INVERSE,     If X has an inverse, return non-zero and store inverse in INVERSE,
    otherwise, return 0 and put garbage in X.     otherwise, return 0 and put garbage in INVERSE.
   
 Copyright (C) 1996 Free Software Foundation, Inc.  Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   
 This file is part of the GNU MP Library.  This file is part of the GNU MP Library.
   
 The GNU MP Library is free software; you can redistribute it and/or modify  The GNU MP Library is free software; you can redistribute it and/or modify
 it under the terms of the GNU Library General Public License as published by  it under the terms of the GNU Lesser General Public License as published by
 the Free Software Foundation; either version 2 of the License, or (at your  the Free Software Foundation; either version 2.1 of the License, or (at your
 option) any later version.  option) any later version.
   
 The GNU MP Library is distributed in the hope that it will be useful, but  The GNU MP Library is distributed in the hope that it will be useful, but
 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 License for more details.  License for more details.
   
 You should have received a copy of the GNU Library General Public License  You should have received a copy of the GNU Lesser General Public License
 along with the GNU MP Library; see the file COPYING.LIB.  If not, write to  along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,  the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */  MA 02111-1307, USA. */
   
 #include "gmp.h"  #include "gmp.h"
   #include "gmp-impl.h"
   
 int  int
 #if __STDC__  #if __STDC__
Line 32  mpz_invert (inverse, x, n)
Line 33  mpz_invert (inverse, x, n)
      mpz_srcptr x, n;       mpz_srcptr x, n;
 #endif  #endif
 {  {
   mpz_t gcd;    mpz_t gcd, tmp;
   int rv;    mp_size_t xsize, nsize, size;
     TMP_DECL (marker);
   
   mpz_init (gcd);    xsize = SIZ (x);
   mpz_gcdext (gcd, inverse, (mpz_ptr) 0, x, n);    nsize = SIZ (n);
   rv = gcd->_mp_size == 1 && (gcd->_mp_d)[0] == 1;    xsize = ABS (xsize);
   mpz_clear (gcd);    nsize = ABS (nsize);
   return rv;    size = MAX (xsize, nsize) + 1;
   
     /* No inverse exists if the leftside operand is 0.  Likewise, no
        inverse exists if the mod operand is 1.  */
     if (xsize == 0 || (nsize == 1 && (PTR (n))[0] == 1))
       return 0;
   
     TMP_MARK (marker);
   
     MPZ_TMP_INIT (gcd, size);
     MPZ_TMP_INIT (tmp, size);
     mpz_gcdext (gcd, tmp, (mpz_ptr) 0, x, n);
   
     /* If no inverse existed, return with an indication of that.  */
     if (gcd->_mp_size != 1 || (gcd->_mp_d)[0] != 1)
       {
         TMP_FREE (marker);
         return 0;
       }
   
     /* Make sure we return a positive inverse.  */
     if (SIZ (tmp) < 0)
       {
         if (SIZ (n) < 0)
           mpz_sub (inverse, tmp, n);
         else
           mpz_add (inverse, tmp, n);
       }
     else
       mpz_set (inverse, tmp);
   
     TMP_FREE (marker);
     return 1;
 }  }
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