1*86d7f5d3SJohn Marino /* mpn_redc_2. Set cp[] <- up[]/R^n mod mp[]. Clobber up[].
2*86d7f5d3SJohn Marino mp[] is n limbs; up[] is 2n limbs.
3*86d7f5d3SJohn Marino
4*86d7f5d3SJohn Marino THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE. IT IS ONLY
5*86d7f5d3SJohn Marino SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
6*86d7f5d3SJohn Marino
7*86d7f5d3SJohn Marino Copyright (C) 2000, 2001, 2002, 2004, 2008 Free Software Foundation, Inc.
8*86d7f5d3SJohn Marino
9*86d7f5d3SJohn Marino This file is part of the GNU MP Library.
10*86d7f5d3SJohn Marino
11*86d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
12*86d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
13*86d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
14*86d7f5d3SJohn Marino option) any later version.
15*86d7f5d3SJohn Marino
16*86d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
17*86d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
18*86d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
19*86d7f5d3SJohn Marino License for more details.
20*86d7f5d3SJohn Marino
21*86d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
22*86d7f5d3SJohn Marino along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
23*86d7f5d3SJohn Marino
24*86d7f5d3SJohn Marino #include "gmp.h"
25*86d7f5d3SJohn Marino #include "gmp-impl.h"
26*86d7f5d3SJohn Marino #include "longlong.h"
27*86d7f5d3SJohn Marino
28*86d7f5d3SJohn Marino
29*86d7f5d3SJohn Marino #if GMP_NAIL_BITS != 0
30*86d7f5d3SJohn Marino you lose
31*86d7f5d3SJohn Marino #endif
32*86d7f5d3SJohn Marino
33*86d7f5d3SJohn Marino /* For testing purposes, define our own mpn_addmul_2 if there is none already
34*86d7f5d3SJohn Marino available. */
35*86d7f5d3SJohn Marino #ifndef HAVE_NATIVE_mpn_addmul_2
36*86d7f5d3SJohn Marino mp_limb_t
mpn_addmul_2(mp_ptr rp,mp_srcptr up,mp_size_t n,mp_srcptr vp)37*86d7f5d3SJohn Marino mpn_addmul_2 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_srcptr vp)
38*86d7f5d3SJohn Marino {
39*86d7f5d3SJohn Marino rp[n] = mpn_addmul_1 (rp, up, n, vp[0]);
40*86d7f5d3SJohn Marino return mpn_addmul_1 (rp + 1, up, n, vp[1]);
41*86d7f5d3SJohn Marino }
42*86d7f5d3SJohn Marino #endif
43*86d7f5d3SJohn Marino
44*86d7f5d3SJohn Marino #if defined (__GNUC__) && defined (__ia64) && W_TYPE_SIZE == 64
45*86d7f5d3SJohn Marino #define umul2low(ph, pl, uh, ul, vh, vl) \
46*86d7f5d3SJohn Marino do { \
47*86d7f5d3SJohn Marino mp_limb_t _ph, _pl; \
48*86d7f5d3SJohn Marino __asm__ ("xma.hu %0 = %3, %5, f0\n\t" \
49*86d7f5d3SJohn Marino "xma.l %1 = %3, %5, f0\n\t" \
50*86d7f5d3SJohn Marino ";;\n\t" \
51*86d7f5d3SJohn Marino "xma.l %0 = %3, %4, %0\n\t" \
52*86d7f5d3SJohn Marino ";;\n\t" \
53*86d7f5d3SJohn Marino "xma.l %0 = %2, %5, %0" \
54*86d7f5d3SJohn Marino : "=&f" (ph), "=&f" (pl) \
55*86d7f5d3SJohn Marino : "f" (uh), "f" (ul), "f" (vh), "f" (vl)); \
56*86d7f5d3SJohn Marino } while (0)
57*86d7f5d3SJohn Marino #endif
58*86d7f5d3SJohn Marino
59*86d7f5d3SJohn Marino #ifndef umul2low
60*86d7f5d3SJohn Marino #define umul2low(ph, pl, uh, ul, vh, vl) \
61*86d7f5d3SJohn Marino do { \
62*86d7f5d3SJohn Marino mp_limb_t _ph, _pl; \
63*86d7f5d3SJohn Marino umul_ppmm (_ph, _pl, ul, vl); \
64*86d7f5d3SJohn Marino (ph) = _ph + (ul) * (vh) + (uh) * (vl); \
65*86d7f5d3SJohn Marino (pl) = _pl; \
66*86d7f5d3SJohn Marino } while (0)
67*86d7f5d3SJohn Marino #endif
68*86d7f5d3SJohn Marino
69*86d7f5d3SJohn Marino void
mpn_redc_2(mp_ptr rp,mp_ptr up,mp_srcptr mp,mp_size_t n,mp_srcptr mip)70*86d7f5d3SJohn Marino mpn_redc_2 (mp_ptr rp, mp_ptr up, mp_srcptr mp, mp_size_t n, mp_srcptr mip)
71*86d7f5d3SJohn Marino {
72*86d7f5d3SJohn Marino mp_limb_t q[2];
73*86d7f5d3SJohn Marino mp_size_t j;
74*86d7f5d3SJohn Marino mp_limb_t upn;
75*86d7f5d3SJohn Marino mp_limb_t cy;
76*86d7f5d3SJohn Marino
77*86d7f5d3SJohn Marino ASSERT (n > 0);
78*86d7f5d3SJohn Marino ASSERT_MPN (up, 2*n);
79*86d7f5d3SJohn Marino
80*86d7f5d3SJohn Marino if ((n & 1) != 0)
81*86d7f5d3SJohn Marino {
82*86d7f5d3SJohn Marino up[0] = mpn_addmul_1 (up, mp, n, (up[0] * mip[0]) & GMP_NUMB_MASK);
83*86d7f5d3SJohn Marino up++;
84*86d7f5d3SJohn Marino }
85*86d7f5d3SJohn Marino
86*86d7f5d3SJohn Marino for (j = n - 2; j >= 0; j -= 2)
87*86d7f5d3SJohn Marino {
88*86d7f5d3SJohn Marino umul2low (q[1], q[0], mip[1], mip[0], up[1], up[0]);
89*86d7f5d3SJohn Marino upn = up[n]; /* mpn_addmul_2 overwrites this */
90*86d7f5d3SJohn Marino up[1] = mpn_addmul_2 (up, mp, n, q);
91*86d7f5d3SJohn Marino up[0] = up[n];
92*86d7f5d3SJohn Marino up[n] = upn;
93*86d7f5d3SJohn Marino up += 2;
94*86d7f5d3SJohn Marino }
95*86d7f5d3SJohn Marino cy = mpn_add_n (rp, up, up - n, n);
96*86d7f5d3SJohn Marino if (cy != 0)
97*86d7f5d3SJohn Marino mpn_sub_n (rp, rp, mp, n);
98*86d7f5d3SJohn Marino }
99