tdiv_q_2exp.c revision 1.1.1.3
1 1.1 mrg /* mpz_tdiv_q_2exp -- Divide an integer by 2**CNT. Round the quotient 2 1.1 mrg towards -infinity. 3 1.1 mrg 4 1.1.1.2 mrg Copyright 1991, 1993, 1994, 1996, 2001, 2002, 2012 Free Software Foundation, 5 1.1.1.2 mrg Inc. 6 1.1 mrg 7 1.1 mrg This file is part of the GNU MP Library. 8 1.1 mrg 9 1.1 mrg The GNU MP Library is free software; you can redistribute it and/or modify 10 1.1.1.3 mrg it under the terms of either: 11 1.1.1.3 mrg 12 1.1.1.3 mrg * the GNU Lesser General Public License as published by the Free 13 1.1.1.3 mrg Software Foundation; either version 3 of the License, or (at your 14 1.1.1.3 mrg option) any later version. 15 1.1.1.3 mrg 16 1.1.1.3 mrg or 17 1.1.1.3 mrg 18 1.1.1.3 mrg * the GNU General Public License as published by the Free Software 19 1.1.1.3 mrg Foundation; either version 2 of the License, or (at your option) any 20 1.1.1.3 mrg later version. 21 1.1.1.3 mrg 22 1.1.1.3 mrg or both in parallel, as here. 23 1.1 mrg 24 1.1 mrg The GNU MP Library is distributed in the hope that it will be useful, but 25 1.1 mrg WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 26 1.1.1.3 mrg or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 27 1.1.1.3 mrg for more details. 28 1.1 mrg 29 1.1.1.3 mrg You should have received copies of the GNU General Public License and the 30 1.1.1.3 mrg GNU Lesser General Public License along with the GNU MP Library. If not, 31 1.1.1.3 mrg see https://www.gnu.org/licenses/. */ 32 1.1 mrg 33 1.1 mrg #include "gmp.h" 34 1.1 mrg #include "gmp-impl.h" 35 1.1 mrg 36 1.1 mrg void 37 1.1.1.2 mrg mpz_tdiv_q_2exp (mpz_ptr r, mpz_srcptr u, mp_bitcnt_t cnt) 38 1.1 mrg { 39 1.1.1.2 mrg mp_size_t un, rn; 40 1.1 mrg mp_size_t limb_cnt; 41 1.1.1.2 mrg mp_ptr rp; 42 1.1.1.2 mrg mp_srcptr up; 43 1.1 mrg 44 1.1.1.2 mrg un = SIZ(u); 45 1.1 mrg limb_cnt = cnt / GMP_NUMB_BITS; 46 1.1.1.2 mrg rn = ABS (un) - limb_cnt; 47 1.1.1.2 mrg 48 1.1.1.2 mrg if (rn <= 0) 49 1.1.1.2 mrg rn = 0; 50 1.1 mrg else 51 1.1 mrg { 52 1.1.1.2 mrg rp = MPZ_REALLOC (r, rn); 53 1.1.1.2 mrg up = PTR(u) + limb_cnt; 54 1.1 mrg 55 1.1 mrg cnt %= GMP_NUMB_BITS; 56 1.1 mrg if (cnt != 0) 57 1.1 mrg { 58 1.1.1.2 mrg mpn_rshift (rp, up, rn, cnt); 59 1.1.1.2 mrg rn -= rp[rn - 1] == 0; 60 1.1 mrg } 61 1.1 mrg else 62 1.1 mrg { 63 1.1.1.2 mrg MPN_COPY_INCR (rp, up, rn); 64 1.1 mrg } 65 1.1 mrg } 66 1.1.1.2 mrg 67 1.1.1.2 mrg SIZ(r) = un >= 0 ? rn : -rn; 68 1.1 mrg } 69
Indexes created Sun Mar 01 05:31:48 UTC 2026