99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/* mpn_redc_2. Set cp[] <- up[]/R^n mod mp[]. Clobber up[].
|
|
mp[] is n limbs; up[] is 2n limbs.
|
|
|
|
THIS IS AN INTERNAL FUNCTION WITH A MUTABLE INTERFACE. IT IS ONLY
|
|
SAFE TO REACH THIS FUNCTION THROUGH DOCUMENTED INTERFACES.
|
|
|
|
Copyright (C) 2000, 2001, 2002, 2004, 2008 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 "mpir.h"
|
|
#include "gmp-impl.h"
|
|
#include "longlong.h"
|
|
|
|
|
|
#if GMP_NAIL_BITS != 0
|
|
you lose
|
|
#endif
|
|
|
|
/* For testing purposes, define our own mpn_addmul_2 if there is none already
|
|
available. */
|
|
#ifndef HAVE_NATIVE_mpn_addmul_2
|
|
mp_limb_t
|
|
mpn_addmul_2 (mp_ptr rp, mp_srcptr up, mp_size_t n, mp_srcptr vp)
|
|
{
|
|
rp[n] = mpn_addmul_1 (rp, up, n, vp[0]);
|
|
return mpn_addmul_1 (rp + 1, up, n, vp[1]);
|
|
}
|
|
#endif
|
|
|
|
#if defined (__GNUC__) && defined (__ia64) && W_TYPE_SIZE == 64
|
|
#define umul2low(ph, pl, uh, ul, vh, vl) \
|
|
do { \
|
|
mp_limb_t _ph, _pl; \
|
|
__asm__ ("xma.hu %0 = %3, %5, f0\n\t" \
|
|
"xma.l %1 = %3, %5, f0\n\t" \
|
|
";;\n\t" \
|
|
"xma.l %0 = %3, %4, %0\n\t" \
|
|
";;\n\t" \
|
|
"xma.l %0 = %2, %5, %0" \
|
|
: "=&f" (ph), "=&f" (pl) \
|
|
: "f" (uh), "f" (ul), "f" (vh), "f" (vl)); \
|
|
} while (0)
|
|
#endif
|
|
|
|
#ifndef umul2low
|
|
#define umul2low(ph, pl, uh, ul, vh, vl) \
|
|
do { \
|
|
mp_limb_t _ph, _pl; \
|
|
umul_ppmm (_ph, _pl, ul, vl); \
|
|
(ph) = _ph + (ul) * (vh) + (uh) * (vl); \
|
|
(pl) = _pl; \
|
|
} while (0)
|
|
#endif
|
|
|
|
void
|
|
mpn_redc_2 (mp_ptr rp, mp_ptr up, mp_srcptr mp, mp_size_t n, mp_srcptr mip)
|
|
{
|
|
mp_limb_t q[2];
|
|
mp_size_t j;
|
|
mp_limb_t upn;
|
|
mp_limb_t cy;
|
|
|
|
ASSERT (n > 0);
|
|
ASSERT_MPN (up, 2*n);
|
|
|
|
if ((n & 1) != 0)
|
|
{
|
|
up[0] = mpn_addmul_1 (up, mp, n, (up[0] * mip[0]) & GMP_NUMB_MASK);
|
|
up++;
|
|
}
|
|
|
|
for (j = n - 2; j >= 0; j -= 2)
|
|
{
|
|
umul2low (q[1], q[0], mip[1], mip[0], up[1], up[0]);
|
|
upn = up[n]; /* mpn_addmul_2 overwrites this */
|
|
up[1] = mpn_addmul_2 (up, mp, n, q);
|
|
up[0] = up[n];
|
|
up[n] = upn;
|
|
up += 2;
|
|
}
|
|
cy = mpn_add_n (rp, up, up - n, n);
|
|
if (cy != 0)
|
|
mpn_sub_n (rp, rp, mp, n);
|
|
}
|