Line | Count | Source (jump to first uncovered line) |
1 | | /* mpz_mul_2exp -- Multiply a bignum by 2**CNT |
2 | | |
3 | | Copyright 1991, 1993, 1994, 1996, 2001, 2002, 2012 Free Software Foundation, |
4 | | Inc. |
5 | | |
6 | | This file is part of the GNU MP Library. |
7 | | |
8 | | The GNU MP Library is free software; you can redistribute it and/or modify |
9 | | it under the terms of either: |
10 | | |
11 | | * the GNU Lesser General Public License as published by the Free |
12 | | Software Foundation; either version 3 of the License, or (at your |
13 | | option) any later version. |
14 | | |
15 | | or |
16 | | |
17 | | * the GNU General Public License as published by the Free Software |
18 | | Foundation; either version 2 of the License, or (at your option) any |
19 | | later version. |
20 | | |
21 | | or both in parallel, as here. |
22 | | |
23 | | The GNU MP Library is distributed in the hope that it will be useful, but |
24 | | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
25 | | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
26 | | for more details. |
27 | | |
28 | | You should have received copies of the GNU General Public License and the |
29 | | GNU Lesser General Public License along with the GNU MP Library. If not, |
30 | | see https://www.gnu.org/licenses/. */ |
31 | | |
32 | | #include "gmp-impl.h" |
33 | | |
34 | | void |
35 | | mpz_mul_2exp (mpz_ptr r, mpz_srcptr u, mp_bitcnt_t cnt) |
36 | 0 | { |
37 | 0 | mp_size_t un, rn; |
38 | 0 | mp_size_t limb_cnt; |
39 | 0 | mp_ptr rp; |
40 | 0 | mp_srcptr up; |
41 | 0 | mp_limb_t rlimb; |
42 | |
|
43 | 0 | un = ABSIZ (u); |
44 | 0 | limb_cnt = cnt / GMP_NUMB_BITS; |
45 | 0 | rn = un + limb_cnt; |
46 | |
|
47 | 0 | if (un == 0) |
48 | 0 | rn = 0; |
49 | 0 | else |
50 | 0 | { |
51 | 0 | rp = MPZ_REALLOC (r, rn + 1); |
52 | 0 | up = PTR(u); |
53 | |
|
54 | 0 | cnt %= GMP_NUMB_BITS; |
55 | 0 | if (cnt != 0) |
56 | 0 | { |
57 | 0 | rlimb = mpn_lshift (rp + limb_cnt, up, un, cnt); |
58 | 0 | rp[rn] = rlimb; |
59 | 0 | rn += (rlimb != 0); |
60 | 0 | } |
61 | 0 | else |
62 | 0 | { |
63 | 0 | MPN_COPY_DECR (rp + limb_cnt, up, un); |
64 | 0 | } |
65 | | |
66 | | /* Zero all whole limbs at low end. Do it here and not before calling |
67 | | mpn_lshift, not to lose for U == R. */ |
68 | 0 | MPN_ZERO (rp, limb_cnt); |
69 | 0 | } |
70 | |
|
71 | 0 | SIZ(r) = SIZ(u) >= 0 ? rn : -rn; |
72 | 0 | } |