xref: /netbsd-src/external/lgpl3/gmp/dist/mpn/generic/mulmid_n.c (revision f89f6560d453f5e37386cc7938c072d2f528b9fa)
1 /* mpn_mulmid_n -- balanced middle product
2 
3    Contributed by David Harvey.
4 
5    THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE.  IT IS ONLY
6    SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES.  IN FACT, IT IS ALMOST
7    GUARANTEED THAT IT'LL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
8 
9 Copyright 2011 Free Software Foundation, Inc.
10 
11 This file is part of the GNU MP Library.
12 
13 The GNU MP Library is free software; you can redistribute it and/or modify
14 it under the terms of the GNU Lesser General Public License as published by
15 the Free Software Foundation; either version 3 of the License, or (at your
16 option) any later version.
17 
18 The GNU MP Library is distributed in the hope that it will be useful, but
19 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
20 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
21 License for more details.
22 
23 You should have received a copy of the GNU Lesser General Public License
24 along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
25 
26 
27 #include "gmp.h"
28 #include "gmp-impl.h"
29 
30 
31 void
32 mpn_mulmid_n (mp_ptr rp, mp_srcptr ap, mp_srcptr bp, mp_size_t n)
33 {
34   ASSERT (n >= 1);
35   ASSERT (! MPN_OVERLAP_P (rp, n + 2, ap, 2*n - 1));
36   ASSERT (! MPN_OVERLAP_P (rp, n + 2, bp, n));
37 
38   if (n < MULMID_TOOM42_THRESHOLD)
39     {
40       mpn_mulmid_basecase (rp, ap, 2*n - 1, bp, n);
41     }
42   else
43     {
44       mp_ptr scratch;
45       TMP_DECL;
46       TMP_MARK;
47       scratch = TMP_ALLOC_LIMBS (mpn_toom42_mulmid_itch (n));
48       mpn_toom42_mulmid (rp, ap, bp, n, scratch);
49       TMP_FREE;
50     }
51 }
52