Imported gcc-4.4.3

[msp430-gcc.git] / mpfr / uceil_exp2.c

diff --git a/mpfr/uceil_exp2.c b/mpfr/uceil_exp2.c
new file mode 100644 (file)
index 0000000..42a6c01
--- /dev/null
+++ b/mpfr/uceil_exp2.c
@@ -0,0 +1,65 @@
+/* __gmpfr_ceil_exp2 - returns y >= 2^d
+
+Copyright 1999, 2000, 2001, 2002, 2003, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao 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 2.1 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.LIB.  If not, write to
+the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+MA 02110-1301, USA. */
+
+#include "mpfr-impl.h"
+
+/* returns y >= 2^d, assuming that d <= 1024
+   for d integer, returns exactly 2^d
+*/
+double
+__gmpfr_ceil_exp2 (double d)
+{
+  long exp;
+#if _GMP_IEEE_FLOATS
+  union ieee_double_extract x;
+#else
+  struct {double d;} x;
+#endif
+
+  MPFR_ASSERTN(d <= 1024.0);
+  exp = (long) d;
+  if (d != (double) exp)
+    exp++;
+  /* now exp = ceil(d) */
+  x.d = 1.0;
+#if _GMP_IEEE_FLOATS
+  x.s.exp = exp <= -1022 ? 1 : 1023 + exp;
+#else
+  if (exp >= 0)
+    {
+      while (exp != 0)
+        {
+          x.d *= 2.0;
+          exp--;
+        }
+    }
+  else
+    {
+      while (exp != 0)
+        {
+        x.d *= (1.0 / 2.0);
+        exp++;
+        }
+    }
+#endif
+  return x.d;
+}