Implemented changes suggested in

<https://sympa.inria.fr/sympa/arc/mpfr/2007-07/msg00123.html>.
* Made mpfr_copysign() like the corresponding function in IEEE 754
  (was an internal function until now).
* Added mpfr_signbit() and mpfr_setsign().
* Documented these three functions.
* Updated TODO.


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@4759 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 30 insertions, 0 deletions

diff --git a/setsign.c b/setsign.c
new file mode 100644
index 000000000..ff099e8f8
--- /dev/null
+++ b/setsign.c
@@ -0,0 +1,30 @@
+/* mpfr_setsign -- Produce a value with the magnitude of x and sign bit s
+
+Copyright 2007 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao projects, INRIA.
+
+This file is part of the MPFR Library.
+
+The 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 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 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 "mpfr-impl.h"
+
+#undef mpfr_setsign
+int
+mpfr_setsign (mpfr_ptr z, mpfr_srcptr x, int s, mp_rnd_t rnd_mode)
+{
+  return mpfr_set4 (z, x, rnd_mode, s ? -1 : 1);
+}