1 /* mpz_tdiv_r_2exp -- Divide a integer by 2**CNT and produce a remainder.
3 Copyright 1991, 1993, 1994, 1995, 2001, 2002 Free Software Foundation, Inc.
5 This file is part of the GNU MP Library.
7 The GNU MP Library is free software; you can redistribute it and/or modify
8 it under the terms of the GNU Lesser General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or (at your
10 option) any later version.
12 The GNU MP Library is distributed in the hope that it will be useful, but
13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15 License for more details.
17 You should have received a copy of the GNU Lesser General Public License
18 along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
24 mpz_tdiv_r_2exp (mpz_ptr res, mpz_srcptr in, unsigned long int cnt)
26 mp_size_t in_size = ABS (in->_mp_size);
28 mp_size_t limb_cnt = cnt / GMP_NUMB_BITS;
29 mp_srcptr in_ptr = in->_mp_d;
31 if (in_size > limb_cnt)
33 /* The input operand is (probably) greater than 2**CNT. */
36 x = in_ptr[limb_cnt] & (((mp_limb_t) 1 << cnt % GMP_NUMB_BITS) - 1);
39 res_size = limb_cnt + 1;
40 if (res->_mp_alloc < res_size)
41 _mpz_realloc (res, res_size);
43 res->_mp_d[limb_cnt] = x;
48 MPN_NORMALIZE (in_ptr, res_size);
50 if (res->_mp_alloc < res_size)
51 _mpz_realloc (res, res_size);
58 /* The input operand is smaller than 2**CNT. We perform a no-op,
59 apart from that we might need to copy IN to RES. */
61 if (res->_mp_alloc < res_size)
62 _mpz_realloc (res, res_size);
68 MPN_COPY (res->_mp_d, in->_mp_d, limb_cnt);
69 res->_mp_size = in->_mp_size >= 0 ? res_size : -res_size;