mirror of
https://review.haiku-os.org/buildtools
synced 2025-02-15 18:27:49 +01:00
4c74403188
Change-Id: Iae65e95cfa0d92091b8b0a424ae36d88efa76aa9 Reviewed-on: https://review.haiku-os.org/c/buildtools/+/3020 Reviewed-by: Adrien Destugues <pulkomandy@gmail.com>
234 lines
6.2 KiB
C
234 lines
6.2 KiB
C
/* mpn_toom43_mul -- Multiply {ap,an} and {bp,bn} where an is nominally 4/3
|
|
times as large as bn. Or more accurately, bn < an < 2 bn.
|
|
|
|
Contributed to the GNU project by Marco Bodrato.
|
|
|
|
The idea of applying toom to unbalanced multiplication is due to Marco
|
|
Bodrato and Alberto Zanoni.
|
|
|
|
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 either:
|
|
|
|
* 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.
|
|
|
|
or
|
|
|
|
* the GNU General Public License as published by the Free Software
|
|
Foundation; either version 2 of the License, or (at your option) any
|
|
later version.
|
|
|
|
or both in parallel, as here.
|
|
|
|
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 General Public License
|
|
for more details.
|
|
|
|
You should have received copies of the GNU General Public License and the
|
|
GNU Lesser General Public License along with the GNU MP Library. If not,
|
|
see https://www.gnu.org/licenses/. */
|
|
|
|
|
|
#include "gmp-impl.h"
|
|
|
|
/* Evaluate in: -2, -1, 0, +1, +2, +inf
|
|
|
|
<-s-><--n--><--n--><--n-->
|
|
___ ______ ______ ______
|
|
|a3_|___a2_|___a1_|___a0_|
|
|
|_b2_|___b1_|___b0_|
|
|
<-t--><--n--><--n-->
|
|
|
|
v0 = a0 * b0 # A(0)*B(0)
|
|
v1 = (a0+ a1+ a2+ a3)*(b0+ b1+ b2) # A(1)*B(1) ah <= 3 bh <= 2
|
|
vm1 = (a0- a1+ a2- a3)*(b0- b1+ b2) # A(-1)*B(-1) |ah| <= 1 |bh|<= 1
|
|
v2 = (a0+2a1+4a2+8a3)*(b0+2b1+4b2) # A(2)*B(2) ah <= 14 bh <= 6
|
|
vm2 = (a0-2a1+4a2-8a3)*(b0-2b1+4b2) # A(-2)*B(-2) |ah| <= 9 |bh|<= 4
|
|
vinf= a3 * b2 # A(inf)*B(inf)
|
|
*/
|
|
|
|
void
|
|
mpn_toom43_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;
|
|
enum toom6_flags flags;
|
|
mp_limb_t cy;
|
|
|
|
#define a0 ap
|
|
#define a1 (ap + n)
|
|
#define a2 (ap + 2 * n)
|
|
#define a3 (ap + 3 * n)
|
|
#define b0 bp
|
|
#define b1 (bp + n)
|
|
#define b2 (bp + 2 * n)
|
|
|
|
n = 1 + (3 * an >= 4 * bn ? (an - 1) >> 2 : (bn - 1) / (size_t) 3);
|
|
|
|
s = an - 3 * n;
|
|
t = bn - 2 * n;
|
|
|
|
ASSERT (0 < s && s <= n);
|
|
ASSERT (0 < t && t <= n);
|
|
|
|
/* This is true whenever an >= 25 or bn >= 19, I think. It
|
|
guarantees that we can fit 5 values of size n+1 in the product
|
|
area. */
|
|
ASSERT (s+t >= 5);
|
|
|
|
#define v0 pp /* 2n */
|
|
#define vm1 (scratch) /* 2n+1 */
|
|
#define v1 (pp + 2*n) /* 2n+1 */
|
|
#define vm2 (scratch + 2 * n + 1) /* 2n+1 */
|
|
#define v2 (scratch + 4 * n + 2) /* 2n+1 */
|
|
#define vinf (pp + 5 * n) /* s+t */
|
|
#define bs1 pp /* n+1 */
|
|
#define bsm1 (scratch + 2 * n + 2) /* n+1 */
|
|
#define asm1 (scratch + 3 * n + 3) /* n+1 */
|
|
#define asm2 (scratch + 4 * n + 4) /* n+1 */
|
|
#define bsm2 (pp + n + 1) /* n+1 */
|
|
#define bs2 (pp + 2 * n + 2) /* n+1 */
|
|
#define as2 (pp + 3 * n + 3) /* n+1 */
|
|
#define as1 (pp + 4 * n + 4) /* n+1 */
|
|
|
|
/* Total sccratch need is 6 * n + 3 + 1; we allocate one extra
|
|
limb, because products will overwrite 2n+2 limbs. */
|
|
|
|
#define a0a2 scratch
|
|
#define b0b2 scratch
|
|
#define a1a3 asm1
|
|
#define b1d bsm1
|
|
|
|
/* Compute as2 and asm2. */
|
|
flags = (enum toom6_flags) (toom6_vm2_neg & mpn_toom_eval_dgr3_pm2 (as2, asm2, ap, n, s, a1a3));
|
|
|
|
/* Compute bs2 and bsm2. */
|
|
b1d[n] = mpn_lshift (b1d, b1, n, 1); /* 2b1 */
|
|
cy = mpn_lshift (b0b2, b2, t, 2); /* 4b2 */
|
|
cy += mpn_add_n (b0b2, b0b2, b0, t); /* 4b2 + b0 */
|
|
if (t != n)
|
|
cy = mpn_add_1 (b0b2 + t, b0 + t, n - t, cy);
|
|
b0b2[n] = cy;
|
|
|
|
#if HAVE_NATIVE_mpn_add_n_sub_n
|
|
if (mpn_cmp (b0b2, b1d, n+1) < 0)
|
|
{
|
|
mpn_add_n_sub_n (bs2, bsm2, b1d, b0b2, n+1);
|
|
flags = (enum toom6_flags) (flags ^ toom6_vm2_neg);
|
|
}
|
|
else
|
|
{
|
|
mpn_add_n_sub_n (bs2, bsm2, b0b2, b1d, n+1);
|
|
}
|
|
#else
|
|
mpn_add_n (bs2, b0b2, b1d, n+1);
|
|
if (mpn_cmp (b0b2, b1d, n+1) < 0)
|
|
{
|
|
mpn_sub_n (bsm2, b1d, b0b2, n+1);
|
|
flags = (enum toom6_flags) (flags ^ toom6_vm2_neg);
|
|
}
|
|
else
|
|
{
|
|
mpn_sub_n (bsm2, b0b2, b1d, n+1);
|
|
}
|
|
#endif
|
|
|
|
/* Compute as1 and asm1. */
|
|
flags = (enum toom6_flags) (flags ^ (toom6_vm1_neg & mpn_toom_eval_dgr3_pm1 (as1, asm1, ap, n, s, a0a2)));
|
|
|
|
/* Compute bs1 and bsm1. */
|
|
bsm1[n] = mpn_add (bsm1, b0, n, b2, t);
|
|
#if HAVE_NATIVE_mpn_add_n_sub_n
|
|
if (bsm1[n] == 0 && mpn_cmp (bsm1, b1, n) < 0)
|
|
{
|
|
cy = mpn_add_n_sub_n (bs1, bsm1, b1, bsm1, n);
|
|
bs1[n] = cy >> 1;
|
|
flags = (enum toom6_flags) (flags ^ toom6_vm1_neg);
|
|
}
|
|
else
|
|
{
|
|
cy = mpn_add_n_sub_n (bs1, bsm1, bsm1, b1, n);
|
|
bs1[n] = bsm1[n] + (cy >> 1);
|
|
bsm1[n]-= cy & 1;
|
|
}
|
|
#else
|
|
bs1[n] = bsm1[n] + mpn_add_n (bs1, bsm1, b1, n);
|
|
if (bsm1[n] == 0 && mpn_cmp (bsm1, b1, n) < 0)
|
|
{
|
|
mpn_sub_n (bsm1, b1, bsm1, n);
|
|
flags = (enum toom6_flags) (flags ^ toom6_vm1_neg);
|
|
}
|
|
else
|
|
{
|
|
bsm1[n] -= mpn_sub_n (bsm1, bsm1, b1, n);
|
|
}
|
|
#endif
|
|
|
|
ASSERT (as1[n] <= 3);
|
|
ASSERT (bs1[n] <= 2);
|
|
ASSERT (asm1[n] <= 1);
|
|
ASSERT (bsm1[n] <= 1);
|
|
ASSERT (as2[n] <=14);
|
|
ASSERT (bs2[n] <= 6);
|
|
ASSERT (asm2[n] <= 9);
|
|
ASSERT (bsm2[n] <= 4);
|
|
|
|
/* vm1, 2n+1 limbs */
|
|
mpn_mul_n (vm1, asm1, bsm1, n+1); /* W4 */
|
|
|
|
/* vm2, 2n+1 limbs */
|
|
mpn_mul_n (vm2, asm2, bsm2, n+1); /* W2 */
|
|
|
|
/* v2, 2n+1 limbs */
|
|
mpn_mul_n (v2, as2, bs2, n+1); /* W1 */
|
|
|
|
/* v1, 2n+1 limbs */
|
|
mpn_mul_n (v1, as1, bs1, n+1); /* W3 */
|
|
|
|
/* vinf, s+t limbs */ /* W0 */
|
|
if (s > t) mpn_mul (vinf, a3, s, b2, t);
|
|
else mpn_mul (vinf, b2, t, a3, s);
|
|
|
|
/* v0, 2n limbs */
|
|
mpn_mul_n (v0, ap, bp, n); /* W5 */
|
|
|
|
mpn_toom_interpolate_6pts (pp, n, flags, vm1, vm2, v2, t + s);
|
|
|
|
#undef v0
|
|
#undef vm1
|
|
#undef v1
|
|
#undef vm2
|
|
#undef v2
|
|
#undef vinf
|
|
#undef bs1
|
|
#undef bs2
|
|
#undef bsm1
|
|
#undef bsm2
|
|
#undef asm1
|
|
#undef asm2
|
|
/* #undef as1 */
|
|
/* #undef as2 */
|
|
#undef a0a2
|
|
#undef b0b2
|
|
#undef a1a3
|
|
#undef b1d
|
|
#undef a0
|
|
#undef a1
|
|
#undef a2
|
|
#undef a3
|
|
#undef b0
|
|
#undef b1
|
|
#undef b2
|
|
}
|