]>
Commit | Line | Data |
---|---|---|
28f540f4 RM |
1 | /* __mpn_mul_1 -- Multiply a limb vector with a single limb and |
2 | store the product in a second limb vector. | |
3 | ||
4 | Copyright (C) 1991, 1992, 1993, 1994 Free Software Foundation, 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 the GNU Library General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or (at your | |
11 | option) any later version. | |
12 | ||
13 | The GNU MP Library is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY | |
15 | or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public | |
16 | License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Library General Public License | |
19 | along with the GNU MP Library; see the file COPYING.LIB. If not, write to | |
20 | the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
21 | ||
22 | #include "gmp.h" | |
23 | #include "gmp-impl.h" | |
24 | #include "longlong.h" | |
25 | ||
26 | mp_limb | |
27 | __mpn_mul_1 (res_ptr, s1_ptr, s1_size, s2_limb) | |
28 | register mp_ptr res_ptr; | |
29 | register mp_srcptr s1_ptr; | |
30 | mp_size_t s1_size; | |
31 | register mp_limb s2_limb; | |
32 | { | |
33 | register mp_limb cy_limb; | |
34 | register mp_size_t j; | |
35 | register mp_limb prod_high, prod_low; | |
36 | ||
37 | /* The loop counter and index J goes from -S1_SIZE to -1. This way | |
38 | the loop becomes faster. */ | |
39 | j = -s1_size; | |
40 | ||
41 | /* Offset the base pointers to compensate for the negative indices. */ | |
42 | s1_ptr -= j; | |
43 | res_ptr -= j; | |
44 | ||
45 | cy_limb = 0; | |
46 | do | |
47 | { | |
48 | umul_ppmm (prod_high, prod_low, s1_ptr[j], s2_limb); | |
49 | ||
50 | prod_low += cy_limb; | |
51 | cy_limb = (prod_low < cy_limb) + prod_high; | |
52 | ||
53 | res_ptr[j] = prod_low; | |
54 | } | |
55 | while (++j != 0); | |
56 | ||
57 | return cy_limb; | |
58 | } |