Imported gcc-4.4.3

[msp430-gcc.git] / gmp / mpn / generic / sizeinbase.c

diff --git a/gmp/mpn/generic/sizeinbase.c b/gmp/mpn/generic/sizeinbase.c
new file mode 100644 (file)
index 0000000..edd10b5
--- /dev/null
+++ b/gmp/mpn/generic/sizeinbase.c
@@ -0,0 +1,58 @@
+/* mpn_sizeinbase -- approximation to chars required for an mpn.
+
+   THE FUNCTIONS IN THIS FILE ARE FOR INTERNAL USE ONLY.  THEY'RE ALMOST
+   CERTAIN TO BE SUBJECT TO INCOMPATIBLE CHANGES OR DISAPPEAR COMPLETELY IN
+   FUTURE GNU MP RELEASES.
+
+Copyright 1991, 1993, 1994, 1995, 2001, 2002 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 3 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.  If not, see http://www.gnu.org/licenses/.  */
+
+#include "gmp.h"
+#include "gmp-impl.h"
+#include "longlong.h"
+
+
+/* Same as mpz_sizeinbase, meaning exact for power-of-2 bases, and either
+   exact or 1 too big for other bases.  */
+
+size_t
+mpn_sizeinbase (mp_srcptr xp, mp_size_t xsize, int base)
+{
+  int lb_base, cnt;
+  mp_size_t totbits;
+
+  ASSERT (xsize >= 0);
+  ASSERT (base >= 2);
+  ASSERT (base < numberof (__mp_bases));
+
+  /* Special case for X == 0.  */
+  if (xsize == 0)
+    return 1;
+
+  /* Calculate the total number of significant bits of X.  */
+  count_leading_zeros (cnt, xp[xsize-1]);
+  totbits = xsize * BITS_PER_MP_LIMB - cnt;
+
+  if (POW2_P (base))
+    {
+      /* Special case for powers of 2, giving exact result.  */
+      lb_base = __mp_bases[base].big_base;
+      return (totbits + lb_base - 1) / lb_base;
+    }
+  else
+    return (size_t) (totbits * __mp_bases[base].chars_per_bit_exactly) + 1;
+}