--- /dev/null
+/* mpfr_swap (U, V) -- Swap U and V.
+
+Copyright 2000, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao projects, INRIA.
+
+This file is part of the GNU MPFR Library.
+
+The GNU MPFR Library is free software; you can redistribute it and/or modify
+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 MPFR 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 Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to
+the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+MA 02110-1301, USA. */
+
+#include <string.h>
+
+#include "mpfr-impl.h"
+
+/* Using memcpy is a few slower than swapping by hand. */
+
+void
+mpfr_swap (mpfr_ptr u, mpfr_ptr v)
+{
+ mpfr_prec_t p1, p2;
+ mpfr_sign_t s1, s2;
+ mp_exp_t e1, e2;
+ mp_limb_t *m1, *m2;
+
+ p1 = MPFR_PREC(u);
+ p2 = MPFR_PREC(v);
+ MPFR_PREC(v) = p1;
+ MPFR_PREC(u) = p2;
+
+ s1 = MPFR_SIGN(u);
+ s2 = MPFR_SIGN(v);
+ MPFR_SIGN(v) = s1;
+ MPFR_SIGN(u) = s2;
+
+ e1 = MPFR_EXP(u);
+ e2 = MPFR_EXP(v);
+ MPFR_EXP(v) = e1;
+ MPFR_EXP(u) = e2;
+
+ m1 = MPFR_MANT(u);
+ m2 = MPFR_MANT(v);
+ MPFR_MANT(v) = m1;
+ MPFR_MANT(u) = m2;
+}