1*627f7eb2Smrg /* mpn_mul_1 -- Multiply a limb vector with a single limb and
2*627f7eb2Smrg store the product in a second limb vector.
3*627f7eb2Smrg
4*627f7eb2Smrg Copyright (C) 1991, 1992, 1993, 1994, 1996 Free Software Foundation, Inc.
5*627f7eb2Smrg
6*627f7eb2Smrg This file is part of the GNU MP Library.
7*627f7eb2Smrg
8*627f7eb2Smrg The GNU MP Library is free software; you can redistribute it and/or modify
9*627f7eb2Smrg it under the terms of the GNU Lesser General Public License as published by
10*627f7eb2Smrg the Free Software Foundation; either version 2.1 of the License, or (at your
11*627f7eb2Smrg option) any later version.
12*627f7eb2Smrg
13*627f7eb2Smrg The GNU MP Library is distributed in the hope that it will be useful, but
14*627f7eb2Smrg WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15*627f7eb2Smrg or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16*627f7eb2Smrg License for more details.
17*627f7eb2Smrg
18*627f7eb2Smrg You should have received a copy of the GNU Lesser General Public License
19*627f7eb2Smrg along with the GNU MP Library; see the file COPYING.LIB. If not, write to
20*627f7eb2Smrg the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
21*627f7eb2Smrg MA 02111-1307, USA. */
22*627f7eb2Smrg
23*627f7eb2Smrg #include <config.h>
24*627f7eb2Smrg #include "gmp-impl.h"
25*627f7eb2Smrg
26*627f7eb2Smrg mp_limb_t
mpn_mul_1(res_ptr,s1_ptr,s1_size,s2_limb)27*627f7eb2Smrg mpn_mul_1 (res_ptr, s1_ptr, s1_size, s2_limb)
28*627f7eb2Smrg register mp_ptr res_ptr;
29*627f7eb2Smrg register mp_srcptr s1_ptr;
30*627f7eb2Smrg mp_size_t s1_size;
31*627f7eb2Smrg register mp_limb_t s2_limb;
32*627f7eb2Smrg {
33*627f7eb2Smrg register mp_limb_t cy_limb;
34*627f7eb2Smrg register mp_size_t j;
35*627f7eb2Smrg register mp_limb_t prod_high, prod_low;
36*627f7eb2Smrg
37*627f7eb2Smrg /* The loop counter and index J goes from -S1_SIZE to -1. This way
38*627f7eb2Smrg the loop becomes faster. */
39*627f7eb2Smrg j = -s1_size;
40*627f7eb2Smrg
41*627f7eb2Smrg /* Offset the base pointers to compensate for the negative indices. */
42*627f7eb2Smrg s1_ptr -= j;
43*627f7eb2Smrg res_ptr -= j;
44*627f7eb2Smrg
45*627f7eb2Smrg cy_limb = 0;
46*627f7eb2Smrg do
47*627f7eb2Smrg {
48*627f7eb2Smrg umul_ppmm (prod_high, prod_low, s1_ptr[j], s2_limb);
49*627f7eb2Smrg
50*627f7eb2Smrg prod_low += cy_limb;
51*627f7eb2Smrg cy_limb = (prod_low < cy_limb) + prod_high;
52*627f7eb2Smrg
53*627f7eb2Smrg res_ptr[j] = prod_low;
54*627f7eb2Smrg }
55*627f7eb2Smrg while (++j != 0);
56*627f7eb2Smrg
57*627f7eb2Smrg return cy_limb;
58*627f7eb2Smrg }
59