Reorganisation of the source tree

[ghc-hetmet.git] / rts / gmp / insert-dbl.c

diff --git a/rts/gmp/insert-dbl.c b/rts/gmp/insert-dbl.c
new file mode 100644 (file)
index 0000000..dc88a56
--- /dev/null
+++ b/rts/gmp/insert-dbl.c
@@ -0,0 +1,98 @@
+/* __gmp_insert_double -- convert from array of mp_limb_t to double.
+
+Copyright (C) 1996, 1997, 1999, 2000 Free Software Foundation, Inc.
+
+This file is part of the GNU MP Library.
+
+The GNU MP 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 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MP 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 MP Library; see the file COPYING.LIB.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+MA 02111-1307, USA. */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+
+#ifdef XDEBUG
+#undef _GMP_IEEE_FLOATS
+#endif
+
+#ifndef _GMP_IEEE_FLOATS
+#define _GMP_IEEE_FLOATS 0
+#endif
+
+double
+#if __STDC__
+__gmp_scale2 (double d, int exp)
+#else
+__gmp_scale2 (d, exp)
+     double d;
+     int exp;
+#endif
+{
+#if _GMP_IEEE_FLOATS
+  {
+#if defined (__alpha) && __GNUC__ == 2 && __GNUC_MINOR__ == 8
+    /* Work around alpha-specific bug in GCC 2.8.x.  */
+    volatile
+#endif
+    union ieee_double_extract x;
+    x.d = d;
+    exp += x.s.exp;
+    x.s.exp = exp;
+    if (exp >= 2047)
+      {
+       /* Return +-infinity */
+       x.s.exp = 2047;
+       x.s.manl = x.s.manh = 0;
+      }
+    else if (exp < 1)
+      {
+       x.s.exp = 1;            /* smallest exponent (biased) */
+       /* Divide result by 2 until we have scaled it to the right IEEE
+          denormalized number, but stop if it becomes zero.  */
+       while (exp < 1 && x.d != 0)
+         {
+           x.d *= 0.5;
+           exp++;
+         }
+      }
+    return x.d;
+  }
+#else
+  {
+    double factor, r;
+
+    factor = 2.0;
+    if (exp < 0)
+      {
+       factor = 0.5;
+       exp = -exp;
+      }
+    r = d;
+    if (exp != 0)
+      {
+       if ((exp & 1) != 0)
+         r *= factor;
+       exp >>= 1;
+       while (exp != 0)
+         {
+           factor *= factor;
+           if ((exp & 1) != 0)
+             r *= factor;
+           exp >>= 1;
+         }
+      }
+    return r;
+  }
+#endif
+}