buildtools/gcc/gmp/mpn/generic/toom33_mul.c
Jérôme Duval b58ddff026 * modified gcc Makefile.in to copy gmp-impl.h and longlong.h headers to build gmp directory (see http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44455 ).
* merged mpfr 3.0.0 and gmp 5.0.1 in buildtools trunk


git-svn-id: file:///srv/svn/repos/haiku/buildtools/trunk@37378 a95241bf-73f2-0310-859d-f6bbb57e9c96
2010-07-03 15:21:01 +00:00

303 lines
7.8 KiB
C

/* mpn_toom33_mul -- Multiply {ap,an} and {p,bn} where an and bn are close in
size. Or more accurately, bn <= an < (3/2)bn.
Contributed to the GNU project by Torbjorn Granlund.
Additional improvements 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 2006, 2007, 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 "gmp.h"
#include "gmp-impl.h"
/* Evaluate in: -1, 0, +1, +2, +inf
<-s--><--n--><--n--><--n-->
____ ______ ______ ______
|_a3_|___a2_|___a1_|___a0_|
|b3_|___b2_|___b1_|___b0_|
<-t-><--n--><--n--><--n-->
v0 = a0 * b0 # A(0)*B(0)
v1 = (a0+ a1+ a2)*(b0+ b1+ b2) # A(1)*B(1) ah <= 2 bh <= 2
vm1 = (a0- a1+ a2)*(b0- b1+ b2) # A(-1)*B(-1) |ah| <= 1 bh <= 1
v2 = (a0+2a1+4a2)*(b0+2b1+4b2) # A(2)*B(2) ah <= 6 bh <= 6
vinf= a2 * b2 # A(inf)*B(inf)
*/
#if TUNE_PROGRAM_BUILD
#define MAYBE_mul_basecase 1
#define MAYBE_mul_toom33 1
#else
#define MAYBE_mul_basecase \
(MUL_TOOM33_THRESHOLD < 3 * MUL_TOOM22_THRESHOLD)
#define MAYBE_mul_toom33 \
(MUL_TOOM44_THRESHOLD >= 3 * MUL_TOOM33_THRESHOLD)
#endif
/* FIXME: TOOM33_MUL_N_REC is not quite right for a balanced
multiplication at the infinity point. We may have
MAYBE_mul_basecase == 0, and still get s just below
MUL_TOOM22_THRESHOLD. If MUL_TOOM33_THRESHOLD == 7, we can even get
s == 1 and mpn_toom22_mul will crash.
*/
#define TOOM33_MUL_N_REC(p, a, b, n, ws) \
do { \
if (MAYBE_mul_basecase \
&& BELOW_THRESHOLD (n, MUL_TOOM22_THRESHOLD)) \
mpn_mul_basecase (p, a, n, b, n); \
else if (! MAYBE_mul_toom33 \
|| BELOW_THRESHOLD (n, MUL_TOOM33_THRESHOLD)) \
mpn_toom22_mul (p, a, n, b, n, ws); \
else \
mpn_toom33_mul (p, a, n, b, n, ws); \
} while (0)
void
mpn_toom33_mul (mp_ptr pp,
mp_srcptr ap, mp_size_t an,
mp_srcptr bp, mp_size_t bn,
mp_ptr scratch)
{
mp_size_t n, s, t;
int vm1_neg;
mp_limb_t cy, vinf0;
mp_ptr gp;
mp_ptr as1, asm1, as2;
mp_ptr bs1, bsm1, bs2;
#define a0 ap
#define a1 (ap + n)
#define a2 (ap + 2*n)
#define b0 bp
#define b1 (bp + n)
#define b2 (bp + 2*n)
n = (an + 2) / (size_t) 3;
s = an - 2 * n;
t = bn - 2 * n;
ASSERT (an >= bn);
ASSERT (0 < s && s <= n);
ASSERT (0 < t && t <= n);
as1 = scratch + 4 * n + 4;
asm1 = scratch + 2 * n + 2;
as2 = pp + n + 1;
bs1 = pp;
bsm1 = scratch + 3 * n + 3; /* we need 4n+4 <= 4n+s+t */
bs2 = pp + 2 * n + 2;
gp = scratch;
vm1_neg = 0;
/* Compute as1 and asm1. */
cy = mpn_add (gp, a0, n, a2, s);
#if HAVE_NATIVE_mpn_add_n_sub_n
if (cy == 0 && mpn_cmp (gp, a1, n) < 0)
{
cy = mpn_add_n_sub_n (as1, asm1, a1, gp, n);
as1[n] = 0;
asm1[n] = 0;
vm1_neg = 1;
}
else
{
cy2 = mpn_add_n_sub_n (as1, asm1, gp, a1, n);
as1[n] = cy + (cy2 >> 1);
asm1[n] = cy - (cy & 1);
}
#else
as1[n] = cy + mpn_add_n (as1, gp, a1, n);
if (cy == 0 && mpn_cmp (gp, a1, n) < 0)
{
mpn_sub_n (asm1, a1, gp, n);
asm1[n] = 0;
vm1_neg = 1;
}
else
{
cy -= mpn_sub_n (asm1, gp, a1, n);
asm1[n] = cy;
}
#endif
/* Compute as2. */
#if HAVE_NATIVE_mpn_rsblsh1_n
cy = mpn_add_n (as2, a2, as1, s);
if (s != n)
cy = mpn_add_1 (as2 + s, as1 + s, n - s, cy);
cy += as1[n];
cy = 2 * cy + mpn_rsblsh1_n (as2, a0, as2, n);
#else
#if HAVE_NATIVE_mpn_addlsh1_n
cy = mpn_addlsh1_n (as2, a1, a2, s);
if (s != n)
cy = mpn_add_1 (as2 + s, a1 + s, n - s, cy);
cy = 2 * cy + mpn_addlsh1_n (as2, a0, as2, n);
#else
cy = mpn_add_n (as2, a2, as1, s);
if (s != n)
cy = mpn_add_1 (as2 + s, as1 + s, n - s, cy);
cy += as1[n];
cy = 2 * cy + mpn_lshift (as2, as2, n, 1);
cy -= mpn_sub_n (as2, as2, a0, n);
#endif
#endif
as2[n] = cy;
/* Compute bs1 and bsm1. */
cy = mpn_add (gp, b0, n, b2, t);
#if HAVE_NATIVE_mpn_add_n_sub_n
if (cy == 0 && mpn_cmp (gp, b1, n) < 0)
{
cy = mpn_add_n_sub_n (bs1, bsm1, b1, gp, n);
bs1[n] = 0;
bsm1[n] = 0;
vm1_neg ^= 1;
}
else
{
cy2 = mpn_add_n_sub_n (bs1, bsm1, gp, b1, n);
bs1[n] = cy + (cy2 >> 1);
bsm1[n] = cy - (cy & 1);
}
#else
bs1[n] = cy + mpn_add_n (bs1, gp, b1, n);
if (cy == 0 && mpn_cmp (gp, b1, n) < 0)
{
mpn_sub_n (bsm1, b1, gp, n);
bsm1[n] = 0;
vm1_neg ^= 1;
}
else
{
cy -= mpn_sub_n (bsm1, gp, b1, n);
bsm1[n] = cy;
}
#endif
/* Compute bs2. */
#if HAVE_NATIVE_mpn_rsblsh1_n
cy = mpn_add_n (bs2, b2, bs1, t);
if (t != n)
cy = mpn_add_1 (bs2 + t, bs1 + t, n - t, cy);
cy += bs1[n];
cy = 2 * cy + mpn_rsblsh1_n (bs2, b0, bs2, n);
#else
#if HAVE_NATIVE_mpn_addlsh1_n
cy = mpn_addlsh1_n (bs2, b1, b2, t);
if (t != n)
cy = mpn_add_1 (bs2 + t, b1 + t, n - t, cy);
cy = 2 * cy + mpn_addlsh1_n (bs2, b0, bs2, n);
#else
cy = mpn_add_n (bs2, bs1, b2, t);
if (t != n)
cy = mpn_add_1 (bs2 + t, bs1 + t, n - t, cy);
cy += bs1[n];
cy = 2 * cy + mpn_lshift (bs2, bs2, n, 1);
cy -= mpn_sub_n (bs2, bs2, b0, n);
#endif
#endif
bs2[n] = cy;
ASSERT (as1[n] <= 2);
ASSERT (bs1[n] <= 2);
ASSERT (asm1[n] <= 1);
ASSERT (bsm1[n] <= 1);
ASSERT (as2[n] <= 6);
ASSERT (bs2[n] <= 6);
#define v0 pp /* 2n */
#define v1 (pp + 2 * n) /* 2n+1 */
#define vinf (pp + 4 * n) /* s+t */
#define vm1 scratch /* 2n+1 */
#define v2 (scratch + 2 * n + 1) /* 2n+2 */
#define scratch_out (scratch + 5 * n + 5)
/* vm1, 2n+1 limbs */
#ifdef SMALLER_RECURSION
TOOM33_MUL_N_REC (vm1, asm1, bsm1, n, scratch_out);
cy = 0;
if (asm1[n] != 0)
cy = bsm1[n] + mpn_add_n (vm1 + n, vm1 + n, bsm1, n);
if (bsm1[n] != 0)
cy += mpn_add_n (vm1 + n, vm1 + n, asm1, n);
vm1[2 * n] = cy;
#else
TOOM33_MUL_N_REC (vm1, asm1, bsm1, n + 1, scratch_out);
#endif
TOOM33_MUL_N_REC (v2, as2, bs2, n + 1, scratch_out); /* v2, 2n+1 limbs */
/* vinf, s+t limbs */
if (s > t) mpn_mul (vinf, a2, s, b2, t);
else TOOM33_MUL_N_REC (vinf, a2, b2, s, scratch_out);
vinf0 = vinf[0]; /* v1 overlaps with this */
#ifdef SMALLER_RECURSION
/* v1, 2n+1 limbs */
TOOM33_MUL_N_REC (v1, as1, bs1, n, scratch_out);
if (as1[n] == 1)
{
cy = bs1[n] + mpn_add_n (v1 + n, v1 + n, bs1, n);
}
else if (as1[n] != 0)
{
#if HAVE_NATIVE_mpn_addlsh1_n
cy = 2 * bs1[n] + mpn_addlsh1_n (v1 + n, v1 + n, bs1, n);
#else
cy = 2 * bs1[n] + mpn_addmul_1 (v1 + n, bs1, n, CNST_LIMB(2));
#endif
}
else
cy = 0;
if (bs1[n] == 1)
{
cy += mpn_add_n (v1 + n, v1 + n, as1, n);
}
else if (bs1[n] != 0)
{
#if HAVE_NATIVE_mpn_addlsh1_n
cy += mpn_addlsh1_n (v1 + n, v1 + n, as1, n);
#else
cy += mpn_addmul_1 (v1 + n, as1, n, CNST_LIMB(2));
#endif
}
v1[2 * n] = cy;
#else
cy = vinf[1];
TOOM33_MUL_N_REC (v1, as1, bs1, n + 1, scratch_out);
vinf[1] = cy;
#endif
TOOM33_MUL_N_REC (v0, ap, bp, n, scratch_out); /* v0, 2n limbs */
mpn_toom_interpolate_5pts (pp, v2, vm1, n, s + t, vm1_neg, vinf0);
}