buildtools/gcc/gmp/mpn/generic/nussbaumer_mul.c
2018-03-19 15:46:45 -05:00

61 lines
1.8 KiB
C

/* mpn_nussbaumer_mul -- Multiply {ap,an} and {bp,bn} using
Nussbaumer's negacyclic convolution.
Contributed to the GNU project by Marco Bodrato.
THE FUNCTION IN THIS FILE IS INTERNAL WITH A MUTABLE INTERFACE. IT IS ONLY
SAFE TO REACH IT THROUGH DOCUMENTED INTERFACES. IN FACT, IT IS ALMOST
GUARANTEED THAT IT WILL CHANGE OR DISAPPEAR IN A FUTURE GNU MP RELEASE.
Copyright 2009 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.
The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library. If not, see http://www.gnu.org/licenses/. */
#include "gmp.h"
#include "gmp-impl.h"
/* Multiply {ap,an} by {bp,bn}, and put the result in {pp, an+bn} */
void
mpn_nussbaumer_mul (mp_ptr pp,
mp_srcptr ap, mp_size_t an,
mp_srcptr bp, mp_size_t bn)
{
mp_size_t rn;
mp_ptr tp;
TMP_DECL;
ASSERT (an >= bn);
ASSERT (bn > 0);
TMP_MARK;
if ((ap == bp) && (an == bn))
{
rn = mpn_sqrmod_bnm1_next_size (2*an);
tp = TMP_ALLOC_LIMBS (mpn_sqrmod_bnm1_itch (rn, an));
mpn_sqrmod_bnm1 (pp, rn, ap, an, tp);
}
else
{
rn = mpn_mulmod_bnm1_next_size (an + bn);
tp = TMP_ALLOC_LIMBS (mpn_mulmod_bnm1_itch (rn, an, bn));
mpn_mulmod_bnm1 (pp, rn, ap, an, bp, bn, tp);
}
TMP_FREE;
}