1 files changed, 38 insertions, 0 deletions
diff --git a/mpfr/src/copysign.c b/mpfr/src/copysign.c
new file mode 100644
index 0000000000..010675ca4e
--- /dev/null
+++ b/mpfr/src/copysign.c
@@ -0,0 +1,38 @@
+/* mpfr_copysign -- Produce a value with the magnitude of x and sign bit of y
+
+Copyright 2001-2004, 2006-2016 Free Software Foundation, Inc.
+Contributed by the AriC and Caramba 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 3 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.LESSER.  If not, see
+http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
+51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
+
+#include "mpfr-impl.h"
+
+ /*
+   The computation of z with magnitude of x and sign of y:
+   z = (-1)^signbit(y) * abs(x), i.e. with the same sign bit as y,
+   even if z is a NaN.
+   Note: This function implements copysign from the IEEE-754 standard
+   when no rounding occurs (e.g. if PREC(z) >= PREC(x)).
+ */
+
+#undef mpfr_copysign
+int
+mpfr_copysign (mpfr_ptr z, mpfr_srcptr x, mpfr_srcptr y, mpfr_rnd_t rnd_mode)
+{
+  return mpfr_set4 (z, x, rnd_mode, MPFR_SIGN (y));
+}