xref: /dragonfly/contrib/gmp/mpn/generic/bdiv_q.c (revision 86d7f5d3)
1*86d7f5d3SJohn Marino /* mpn_bdiv_q -- Hensel division with precomputed inverse, returning quotient.
2*86d7f5d3SJohn Marino 
3*86d7f5d3SJohn Marino    Contributed to the GNU project by Torbjorn Granlund.
4*86d7f5d3SJohn Marino 
5*86d7f5d3SJohn Marino    THE FUNCTIONS IN THIS FILE ARE INTERNAL WITH MUTABLE INTERFACES.  IT IS ONLY
6*86d7f5d3SJohn Marino    SAFE TO REACH THEM THROUGH DOCUMENTED INTERFACES.  IN FACT, IT IS ALMOST
7*86d7f5d3SJohn Marino    GUARANTEED THAT THEY WILL CHANGE OR DISAPPEAR IN A FUTURE GMP RELEASE.
8*86d7f5d3SJohn Marino 
9*86d7f5d3SJohn Marino Copyright 2006, 2007, 2009 Free Software Foundation, Inc.
10*86d7f5d3SJohn Marino 
11*86d7f5d3SJohn Marino This file is part of the GNU MP Library.
12*86d7f5d3SJohn Marino 
13*86d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
14*86d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
15*86d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
16*86d7f5d3SJohn Marino option) any later version.
17*86d7f5d3SJohn Marino 
18*86d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
19*86d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
20*86d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
21*86d7f5d3SJohn Marino License for more details.
22*86d7f5d3SJohn Marino 
23*86d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
24*86d7f5d3SJohn Marino along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
25*86d7f5d3SJohn Marino 
26*86d7f5d3SJohn Marino #include "gmp.h"
27*86d7f5d3SJohn Marino #include "gmp-impl.h"
28*86d7f5d3SJohn Marino 
29*86d7f5d3SJohn Marino 
30*86d7f5d3SJohn Marino /* Computes Q = N / D mod B^n. */
31*86d7f5d3SJohn Marino 
32*86d7f5d3SJohn Marino void
mpn_bdiv_q(mp_ptr qp,mp_srcptr np,mp_size_t nn,mp_srcptr dp,mp_size_t dn,mp_ptr tp)33*86d7f5d3SJohn Marino mpn_bdiv_q (mp_ptr qp,
34*86d7f5d3SJohn Marino 	    mp_srcptr np, mp_size_t nn,
35*86d7f5d3SJohn Marino 	    mp_srcptr dp, mp_size_t dn,
36*86d7f5d3SJohn Marino 	    mp_ptr tp)
37*86d7f5d3SJohn Marino {
38*86d7f5d3SJohn Marino   mp_limb_t di;
39*86d7f5d3SJohn Marino 
40*86d7f5d3SJohn Marino   if (BELOW_THRESHOLD (dn, DC_BDIV_Q_THRESHOLD))
41*86d7f5d3SJohn Marino     {
42*86d7f5d3SJohn Marino       MPN_COPY (tp, np, nn);
43*86d7f5d3SJohn Marino       binvert_limb (di, dp[0]);  di = -di;
44*86d7f5d3SJohn Marino       mpn_sbpi1_bdiv_q (qp, tp, nn, dp, dn, di);
45*86d7f5d3SJohn Marino     }
46*86d7f5d3SJohn Marino   else if (BELOW_THRESHOLD (dn, MU_BDIV_Q_THRESHOLD))
47*86d7f5d3SJohn Marino     {
48*86d7f5d3SJohn Marino       MPN_COPY (tp, np, nn);
49*86d7f5d3SJohn Marino       binvert_limb (di, dp[0]);  di = -di;
50*86d7f5d3SJohn Marino       mpn_dcpi1_bdiv_q (qp, tp, nn, dp, dn, di);
51*86d7f5d3SJohn Marino     }
52*86d7f5d3SJohn Marino   else
53*86d7f5d3SJohn Marino     {
54*86d7f5d3SJohn Marino       mpn_mu_bdiv_q (qp, np, nn, dp, dn, tp);
55*86d7f5d3SJohn Marino     }
56*86d7f5d3SJohn Marino   return;
57*86d7f5d3SJohn Marino }
58*86d7f5d3SJohn Marino 
59*86d7f5d3SJohn Marino mp_size_t
mpn_bdiv_q_itch(mp_size_t nn,mp_size_t dn)60*86d7f5d3SJohn Marino mpn_bdiv_q_itch (mp_size_t nn, mp_size_t dn)
61*86d7f5d3SJohn Marino {
62*86d7f5d3SJohn Marino   if (BELOW_THRESHOLD (dn, MU_BDIV_Q_THRESHOLD))
63*86d7f5d3SJohn Marino     return nn;
64*86d7f5d3SJohn Marino   else
65*86d7f5d3SJohn Marino     return mpn_mu_bdiv_q_itch (nn, dn);
66*86d7f5d3SJohn Marino }
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