/src/libgmp/mpz/cdiv_ui.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* mpz_cdiv_ui -- Division rounding the quotient towards +infinity. The |
2 | | remainder gets the opposite sign as the denominator. In order to make it |
3 | | always fit into the return type, the negative of the true remainder is |
4 | | returned. |
5 | | |
6 | | Copyright 1994-1996, 2001, 2002, 2004, 2005, 2012 Free Software Foundation, |
7 | | Inc. |
8 | | |
9 | | This file is part of the GNU MP Library. |
10 | | |
11 | | The GNU MP Library is free software; you can redistribute it and/or modify |
12 | | it under the terms of either: |
13 | | |
14 | | * the GNU Lesser General Public License as published by the Free |
15 | | Software Foundation; either version 3 of the License, or (at your |
16 | | option) any later version. |
17 | | |
18 | | or |
19 | | |
20 | | * the GNU General Public License as published by the Free Software |
21 | | Foundation; either version 2 of the License, or (at your option) any |
22 | | later version. |
23 | | |
24 | | or both in parallel, as here. |
25 | | |
26 | | The GNU MP Library is distributed in the hope that it will be useful, but |
27 | | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
28 | | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
29 | | for more details. |
30 | | |
31 | | You should have received copies of the GNU General Public License and the |
32 | | GNU Lesser General Public License along with the GNU MP Library. If not, |
33 | | see https://www.gnu.org/licenses/. */ |
34 | | |
35 | | #include "gmp-impl.h" |
36 | | |
37 | | unsigned long int |
38 | | mpz_cdiv_ui (mpz_srcptr dividend, unsigned long int divisor) |
39 | 3.47M | { |
40 | 3.47M | mp_size_t ns, nn; |
41 | 3.47M | mp_ptr np; |
42 | 3.47M | mp_limb_t rl; |
43 | | |
44 | 3.47M | if (UNLIKELY (divisor == 0)) |
45 | 0 | DIVIDE_BY_ZERO; |
46 | | |
47 | 3.47M | ns = SIZ(dividend); |
48 | 3.47M | if (ns == 0) |
49 | 0 | { |
50 | 0 | return 0; |
51 | 0 | } |
52 | | |
53 | 3.47M | nn = ABS(ns); |
54 | 3.47M | np = PTR(dividend); |
55 | | #if BITS_PER_ULONG > GMP_NUMB_BITS /* avoid warnings about shift amount */ |
56 | | if (divisor > GMP_NUMB_MAX) |
57 | | { |
58 | | mp_limb_t dp[2], rp[2]; |
59 | | mp_ptr qp; |
60 | | mp_size_t rn; |
61 | | TMP_DECL; |
62 | | |
63 | | if (nn == 1) /* tdiv_qr requirements; tested above for 0 */ |
64 | | { |
65 | | rl = np[0]; |
66 | | rp[0] = rl; |
67 | | } |
68 | | else |
69 | | { |
70 | | TMP_MARK; |
71 | | dp[0] = divisor & GMP_NUMB_MASK; |
72 | | dp[1] = divisor >> GMP_NUMB_BITS; |
73 | | qp = TMP_ALLOC_LIMBS (nn - 2 + 1); |
74 | | mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2); |
75 | | TMP_FREE; |
76 | | rl = rp[0] + (rp[1] << GMP_NUMB_BITS); |
77 | | } |
78 | | |
79 | | if (rl != 0 && ns >= 0) |
80 | | { |
81 | | rl = divisor - rl; |
82 | | rp[0] = rl & GMP_NUMB_MASK; |
83 | | rp[1] = rl >> GMP_NUMB_BITS; |
84 | | } |
85 | | |
86 | | rn = 1 + (rl > GMP_NUMB_MAX); rn -= (rp[rn - 1] == 0); |
87 | | } |
88 | | else |
89 | | #endif |
90 | 3.47M | { |
91 | 3.47M | rl = mpn_mod_1 (np, nn, (mp_limb_t) divisor); |
92 | 3.47M | if (rl == 0) |
93 | 3.56k | ; |
94 | 3.47M | else |
95 | 3.47M | { |
96 | 3.47M | if (ns >= 0) |
97 | 3.47M | rl = divisor - rl; |
98 | 3.47M | } |
99 | 3.47M | } |
100 | | |
101 | 3.47M | return rl; |
102 | 3.47M | } |