/src/gmp/mpn/bdiv_dbm1c.c
Line | Count | Source |
1 | | /* mpn_bdiv_dbm1c -- divide an mpn number by a divisor of B-1, where B is the |
2 | | limb base. The dbm1c moniker means "Divisor of B Minus 1 with Carry". |
3 | | |
4 | | THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE. IT IS ONLY |
5 | | SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST |
6 | | GUARANTEED THAT IT'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE. |
7 | | |
8 | | Copyright 2008, 2009 Free Software Foundation, Inc. |
9 | | |
10 | | This file is part of the GNU MP Library. |
11 | | |
12 | | The GNU MP Library is free software; you can redistribute it and/or modify |
13 | | it under the terms of either: |
14 | | |
15 | | * the GNU Lesser General Public License as published by the Free |
16 | | Software Foundation; either version 3 of the License, or (at your |
17 | | option) any later version. |
18 | | |
19 | | or |
20 | | |
21 | | * the GNU General Public License as published by the Free Software |
22 | | Foundation; either version 2 of the License, or (at your option) any |
23 | | later version. |
24 | | |
25 | | or both in parallel, as here. |
26 | | |
27 | | The GNU MP Library is distributed in the hope that it will be useful, but |
28 | | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
29 | | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
30 | | for more details. |
31 | | |
32 | | You should have received copies of the GNU General Public License and the |
33 | | GNU Lesser General Public License along with the GNU MP Library. If not, |
34 | | see https://www.gnu.org/licenses/. */ |
35 | | |
36 | | #include "gmp-impl.h" |
37 | | #include "longlong.h" |
38 | | |
39 | | |
40 | | mp_limb_t |
41 | | mpn_bdiv_dbm1c (mp_ptr qp, mp_srcptr ap, mp_size_t n, mp_limb_t bd, mp_limb_t h) |
42 | 7.35M | { |
43 | 7.35M | mp_limb_t a, p0, p1, cy; |
44 | 7.35M | mp_size_t i; |
45 | | |
46 | 550M | for (i = 0; i < n; i++) |
47 | 543M | { |
48 | 543M | a = ap[i]; |
49 | 543M | umul_ppmm (p1, p0, a, bd << GMP_NAIL_BITS); |
50 | 543M | p0 >>= GMP_NAIL_BITS; |
51 | 543M | cy = h < p0; |
52 | 543M | h = (h - p0) & GMP_NUMB_MASK; |
53 | 543M | qp[i] = h; |
54 | 543M | h = h - p1 - cy; |
55 | 543M | } |
56 | | |
57 | 7.35M | return h; |
58 | 7.35M | } |