1 files changed, 55 insertions, 0 deletions
diff --git a/src/set_prec.c b/src/set_prec.c
new file mode 100644
index 000000000..8dde77d94
--- /dev/null
+++ b/src/set_prec.c
@@ -0,0 +1,55 @@
+/* mpfr_set_prec -- reset the precision of a floating-point number
+
+Copyright 1999, 2001, 2002, 2004, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+Contributed by the Arenaire and Caramel 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"
+
+void
+mpfr_set_prec (mpfr_ptr x, mpfr_prec_t p)
+{
+  mp_size_t xsize, xoldsize;
+  mp_ptr tmp;
+
+  /* first, check if p is correct */
+  MPFR_ASSERTN (p >= MPFR_PREC_MIN && p <= MPFR_PREC_MAX);
+
+  /* Calculate the new number of limbs */
+  xsize = (p - 1) / GMP_NUMB_BITS + 1;
+
+  /* Realloc only if the new size is greater than the old */
+  xoldsize = MPFR_GET_ALLOC_SIZE (x);
+  if (xsize > xoldsize)
+    {
+      tmp = (mp_ptr) (*__gmp_reallocate_func)
+        (MPFR_GET_REAL_PTR(x), MPFR_MALLOC_SIZE(xoldsize), MPFR_MALLOC_SIZE(xsize));
+      MPFR_SET_MANT_PTR(x, tmp);
+      MPFR_SET_ALLOC_SIZE(x, xsize);
+    }
+  MPFR_PREC (x) = p;
+  MPFR_SET_NAN (x); /* initializes to NaN */
+}
+
+#undef mpfr_get_prec
+mpfr_prec_t
+mpfr_get_prec (mpfr_srcptr x)
+{
+  return MPFR_PREC(x);
+}