1 /* mpz_sizeinbase(x, base) -- return an approximation to the number of
2 character the integer X would have printed in base BASE. The
3 approximation is never too small.
5 Copyright (C) 1991, 1993, 1994, 1995 Free Software Foundation, Inc.
7 This file is part of the GNU MP Library.
9 The GNU MP Library is free software; you can redistribute it and/or modify
10 it under the terms of the GNU Library General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or (at your
12 option) any later version.
14 The GNU MP Library is distributed in the hope that it will be useful, but
15 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
17 License for more details.
19 You should have received a copy of the GNU Library General Public License
20 along with the GNU MP Library; see the file COPYING.LIB. If not, write to
21 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
22 MA 02111-1307, USA. */
30 mpz_sizeinbase (mpz_srcptr x, int base)
32 mpz_sizeinbase (x, base)
37 mp_size_t size = ABS (x->_mp_size);
41 /* Special case for X == 0. */
45 /* Calculate the total number of significant bits of X. */
46 count_leading_zeros (cnt, x->_mp_d[size - 1]);
47 totbits = size * BITS_PER_MP_LIMB - cnt;
49 if ((base & (base - 1)) == 0)
51 /* Special case for powers of 2, giving exact result. */
53 count_leading_zeros (lb_base, base);
54 lb_base = BITS_PER_MP_LIMB - lb_base - 1;
56 return (totbits + lb_base - 1) / lb_base;
59 return (size_t) (totbits * __mp_bases[base].chars_per_bit_exactly) + 1;