1 files changed, 61 insertions, 0 deletions
diff --git a/src/get_z.c b/src/get_z.c
new file mode 100644
index 0000000..13a2e99
--- /dev/null
+++ b/src/get_z.c
@@ -0,0 +1,61 @@
+/* mpfr_get_z -- get a multiple-precision integer from
+                 a floating-point number
+
+Copyright 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
+Contributed by the AriC 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"
+
+int
+mpfr_get_z (mpz_ptr z, mpfr_srcptr f, mpfr_rnd_t rnd)
+{
+  int inex;
+  mpfr_t r;
+  mpfr_exp_t exp;
+
+  if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (f)))
+    {
+      if (MPFR_UNLIKELY (MPFR_NOTZERO (f)))
+        MPFR_SET_ERANGE ();
+      mpz_set_ui (z, 0);
+      /* The ternary value is 0 even for infinity. Giving the rounding
+         direction in this case would not make much sense anyway, and
+         the direction would not necessarily match rnd. */
+      return 0;
+    }
+
+  exp = MPFR_GET_EXP (f);
+  /* if exp <= 0, then |f|<1, thus |o(f)|<=1 */
+  MPFR_ASSERTN (exp < 0 || exp <= MPFR_PREC_MAX);
+  mpfr_init2 (r, (exp < (mpfr_exp_t) MPFR_PREC_MIN ?
+                  MPFR_PREC_MIN : (mpfr_prec_t) exp));
+  inex = mpfr_rint (r, f, rnd);
+  MPFR_ASSERTN (inex != 1 && inex != -1); /* integral part of f is
+                                             representable in r */
+  MPFR_ASSERTN (MPFR_IS_FP (r));
+  exp = mpfr_get_z_2exp (z, r);
+  if (exp >= 0)
+    mpz_mul_2exp (z, z, exp);
+  else
+    mpz_fdiv_q_2exp (z, z, -exp);
+  mpfr_clear (r);
+
+  return inex;
+}