===================================================================
RCS file: /home/cvs/OpenXM_contrib/gmp/mpz/Attic/invert.c,v
retrieving revision 1.1.1.1
retrieving revision 1.1.1.2
diff -u -p -r1.1.1.1 -r1.1.1.2
--- OpenXM_contrib/gmp/mpz/Attic/invert.c	2000/01/10 15:35:27	1.1.1.1
+++ OpenXM_contrib/gmp/mpz/Attic/invert.c	2000/09/09 14:12:53	1.1.1.2
@@ -1,27 +1,28 @@
 /* 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,
-   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.
 
 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
-the Free Software Foundation; either version 2 of the License, or (at your
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
 option) any later version.
 
 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
-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.
 
-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
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */
 
 #include "gmp.h"
+#include "gmp-impl.h"
 
 int
 #if __STDC__
@@ -32,12 +33,45 @@ mpz_invert (inverse, x, n)
      mpz_srcptr x, n;
 #endif
 {
-  mpz_t gcd;
-  int rv;
+  mpz_t gcd, tmp;
+  mp_size_t xsize, nsize, size;
+  TMP_DECL (marker);
 
-  mpz_init (gcd);
-  mpz_gcdext (gcd, inverse, (mpz_ptr) 0, x, n);
-  rv = gcd->_mp_size == 1 && (gcd->_mp_d)[0] == 1;
-  mpz_clear (gcd);
-  return rv;
+  xsize = SIZ (x);
+  nsize = SIZ (n);
+  xsize = ABS (xsize);
+  nsize = ABS (nsize);
+  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;
 }