--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/realmpfr.c	Mon May 24 12:47:05 2010 +0900
@@ -0,0 +1,101 @@
+/* Conversion routines from GCC internal float representation to MPFR.
+   Copyright (C) 2010
+
+   This file is part of GCC.
+
+   GCC is free software; you can redistribute it and/or modify it under
+   the terms of the GNU General Public License as published by the Free
+   Software Foundation; either version 3, or (at your option) any later
+   version.
+
+   GCC 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 General Public License
+   for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with GCC; see the file COPYING3.  If not see
+   <http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "realmpfr.h"
+#include "tree.h"	/* For TYPE_MODE in real_from_mpfr.  */
+
+/* Convert from REAL_VALUE_TYPE to MPFR.  The caller is responsible
+   for initializing and clearing the MPFR parameter.  */
+
+void
+mpfr_from_real (mpfr_ptr m, const REAL_VALUE_TYPE *r, mp_rnd_t rndmode)
+{
+  /* We use a string as an intermediate type.  */
+  char buf[128];
+  int ret;
+
+  /* Take care of Infinity and NaN.  */
+  if (r->cl == rvc_inf)
+    {
+      mpfr_set_inf (m, r->sign == 1 ? -1 : 1);
+      return;
+    }
+
+  if (r->cl == rvc_nan)
+    {
+      mpfr_set_nan (m);
+      return;
+    }
+
+  real_to_hexadecimal (buf, r, sizeof (buf), 0, 1);
+  /* mpfr_set_str() parses hexadecimal floats from strings in the same
+     format that GCC will output them.  Nothing extra is needed.  */
+  ret = mpfr_set_str (m, buf, 16, rndmode);
+  gcc_assert (ret == 0);
+}
+
+/* Convert from MPFR to REAL_VALUE_TYPE, for a given type TYPE and rounding
+   mode RNDMODE.  TYPE is only relevant if M is a NaN.  */
+
+void
+real_from_mpfr (REAL_VALUE_TYPE *r, mpfr_srcptr m, tree type, mp_rnd_t rndmode)
+{
+  /* We use a string as an intermediate type.  */
+  char buf[128], *rstr;
+  mp_exp_t exp;
+
+  /* Take care of Infinity and NaN.  */
+  if (mpfr_inf_p (m))
+    {
+      real_inf (r);
+      if (mpfr_sgn (m) < 0)
+	*r = real_value_negate (r);
+      return;
+    }
+
+  if (mpfr_nan_p (m))
+    {
+      real_nan (r, "", 1, TYPE_MODE (type));
+      return;
+    }
+
+  rstr = mpfr_get_str (NULL, &exp, 16, 0, m, rndmode);
+
+  /* The additional 12 chars add space for the sprintf below.  This
+     leaves 6 digits for the exponent which is supposedly enough.  */
+  gcc_assert (rstr != NULL && strlen (rstr) < sizeof (buf) - 12);
+
+  /* REAL_VALUE_ATOF expects the exponent for mantissa * 2**exp,
+     mpfr_get_str returns the exponent for mantissa * 16**exp, adjust
+     for that.  */
+  exp *= 4;
+
+  if (rstr[0] == '-')
+    sprintf (buf, "-0x.%sp%d", &rstr[1], (int) exp);
+  else
+    sprintf (buf, "0x.%sp%d", rstr, (int) exp);
+
+  mpfr_free_str (rstr);
+
+  real_from_string (r, buf);
+}
+