1 files changed, 87 insertions, 0 deletions
diff --git a/mpfr/src/frexp.c b/mpfr/src/frexp.c
new file mode 100644
index 0000000000..c5bcf0f442
--- /dev/null
+++ b/mpfr/src/frexp.c
@@ -0,0 +1,87 @@
+/* mpfr_frexp -- convert to integral and fractional parts
+
+Copyright 2011-2016 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"
+
+int
+mpfr_frexp (mpfr_exp_t *exp, mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t rnd)
+{
+  int inex;
+  unsigned int saved_flags = __gmpfr_flags;
+  MPFR_BLOCK_DECL (flags);
+
+  MPFR_LOG_FUNC
+    (("x[%Pu]=%.*Rg rnd=%d", mpfr_get_prec (x), mpfr_log_prec, x, rnd),
+     ("y[%Pu]=%.*Rg exp=%" MPFR_EXP_FSPEC "d inex=%d", mpfr_get_prec (y),
+      mpfr_log_prec, y, (mpfr_eexp_t) *exp, inex));
+
+  if (MPFR_UNLIKELY(MPFR_IS_SINGULAR(x)))
+    {
+      if (MPFR_IS_NAN(x))
+        {
+          MPFR_SET_NAN(y);
+          MPFR_RET_NAN; /* exp is unspecified */
+        }
+      else if (MPFR_IS_INF(x))
+        {
+          MPFR_SET_INF(y);
+          MPFR_SET_SAME_SIGN(y,x);
+          MPFR_RET(0); /* exp is unspecified */
+        }
+      else
+        {
+          MPFR_SET_ZERO(y);
+          MPFR_SET_SAME_SIGN(y,x);
+          *exp = 0;
+          MPFR_RET(0);
+        }
+    }
+
+  MPFR_BLOCK (flags, inex = mpfr_set (y, x, rnd));
+  __gmpfr_flags = saved_flags;
+
+  /* Possible overflow due to the rounding, no possible underflow. */
+
+  if (MPFR_UNLIKELY (MPFR_OVERFLOW (flags)))
+    {
+      int inex2;
+
+      /* An overflow here means that the exponent of y would be larger than
+         the one of x, thus x would be rounded to the next power of 2, and
+         the returned y should be 1/2 in absolute value, rounded (i.e. with
+         possible underflow or overflow). This also implies that x and y are
+         different objects, so that the exponent of x has not been lost. */
+      MPFR_LOG_MSG (("Internal overflow\n", 0));
+      MPFR_ASSERTD (x != y);
+      *exp = MPFR_GET_EXP (x) + 1;
+      inex2 = mpfr_set_si_2exp (y, MPFR_INT_SIGN (x), -1, rnd);
+      MPFR_LOG_MSG (("inex=%d inex2=%d\n", inex, inex2));
+      if (inex2 != 0)
+        inex = inex2;
+      MPFR_RET (inex);
+    }
+
+  *exp = MPFR_GET_EXP (y);
+  /* Do not use MPFR_SET_EXP because the range has not been checked yet. */
+  MPFR_EXP (y) = 0;
+  return mpfr_check_range (y, inex, rnd);
+}