From 11da511c784eca003deb90c23570f0873954e0de Mon Sep 17 00:00:00 2001 From: Duncan Wilkie Date: Sat, 18 Nov 2023 06:11:09 -0600 Subject: Initial commit. --- gmp-6.3.0/mpn/generic/toom42_mul.c | 234 +++++++++++++++++++++++++++++++++++++ 1 file changed, 234 insertions(+) create mode 100644 gmp-6.3.0/mpn/generic/toom42_mul.c (limited to 'gmp-6.3.0/mpn/generic/toom42_mul.c') diff --git a/gmp-6.3.0/mpn/generic/toom42_mul.c b/gmp-6.3.0/mpn/generic/toom42_mul.c new file mode 100644 index 0000000..e84ce65 --- /dev/null +++ b/gmp-6.3.0/mpn/generic/toom42_mul.c @@ -0,0 +1,234 @@ +/* mpn_toom42_mul -- Multiply {ap,an} and {bp,bn} where an is nominally twice + as large as bn. Or more accurately, (3/2)bn < an < 4bn. + + Contributed to the GNU project by Torbjorn Granlund. + Additional improvements 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 2006-2008, 2012, 2014 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: -1, 0, +1, +2, +inf + + <-s-><--n--><--n--><--n--> + ___ ______ ______ ______ + |a3_|___a2_|___a1_|___a0_| + |_b1_|___b0_| + <-t--><--n--> + + v0 = a0 * b0 # A(0)*B(0) + v1 = (a0+ a1+ a2+ a3)*(b0+ b1) # A(1)*B(1) ah <= 3 bh <= 1 + vm1 = (a0- a1+ a2- a3)*(b0- b1) # A(-1)*B(-1) |ah| <= 1 bh = 0 + v2 = (a0+2a1+4a2+8a3)*(b0+2b1) # A(2)*B(2) ah <= 14 bh <= 2 + vinf= a3 * b1 # A(inf)*B(inf) +*/ + +#define TOOM42_MUL_N_REC(p, a, b, n, ws) \ + do { \ + mpn_mul_n (p, a, b, n); \ + } while (0) + +void +mpn_toom42_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 a0_a2; + mp_ptr as1, asm1, as2; + mp_ptr bs1, bsm1, bs2; + mp_ptr tmp; + TMP_DECL; + +#define a0 ap +#define a1 (ap + n) +#define a2 (ap + 2*n) +#define a3 (ap + 3*n) +#define b0 bp +#define b1 (bp + n) + + n = an >= 2 * bn ? (an + 3) >> 2 : (bn + 1) >> 1; + + s = an - 3 * n; + t = bn - n; + + ASSERT (0 < s && s <= n); + ASSERT (0 < t && t <= n); + + TMP_MARK; + + tmp = TMP_ALLOC_LIMBS (6 * n + 5); + as1 = tmp; tmp += n + 1; + asm1 = tmp; tmp += n + 1; + as2 = tmp; tmp += n + 1; + bs1 = tmp; tmp += n + 1; + bsm1 = tmp; tmp += n; + bs2 = tmp; tmp += n + 1; + + a0_a2 = pp; + + /* Compute as1 and asm1. */ + vm1_neg = mpn_toom_eval_dgr3_pm1 (as1, asm1, ap, n, s, a0_a2) & 1; + + /* Compute as2. */ +#if HAVE_NATIVE_mpn_addlsh1_n + cy = mpn_addlsh1_n (as2, a2, a3, s); + if (s != n) + cy = mpn_add_1 (as2 + s, a2 + s, n - s, cy); + cy = 2 * cy + mpn_addlsh1_n (as2, a1, as2, n); + cy = 2 * cy + mpn_addlsh1_n (as2, a0, as2, n); +#else + cy = mpn_lshift (as2, a3, s, 1); + cy += mpn_add_n (as2, a2, as2, s); + if (s != n) + cy = mpn_add_1 (as2 + s, a2 + s, n - s, cy); + cy = 2 * cy + mpn_lshift (as2, as2, n, 1); + cy += mpn_add_n (as2, a1, as2, n); + cy = 2 * cy + mpn_lshift (as2, as2, n, 1); + cy += mpn_add_n (as2, a0, as2, n); +#endif + as2[n] = cy; + + /* Compute bs1 and bsm1. */ + if (t == n) + { +#if HAVE_NATIVE_mpn_add_n_sub_n + if (mpn_cmp (b0, b1, n) < 0) + { + cy = mpn_add_n_sub_n (bs1, bsm1, b1, b0, n); + vm1_neg ^= 1; + } + else + { + cy = mpn_add_n_sub_n (bs1, bsm1, b0, b1, n); + } + bs1[n] = cy >> 1; +#else + bs1[n] = mpn_add_n (bs1, b0, b1, n); + + if (mpn_cmp (b0, b1, n) < 0) + { + mpn_sub_n (bsm1, b1, b0, n); + vm1_neg ^= 1; + } + else + { + mpn_sub_n (bsm1, b0, b1, n); + } +#endif + } + else + { + bs1[n] = mpn_add (bs1, b0, n, b1, t); + + if (mpn_zero_p (b0 + t, n - t) && mpn_cmp (b0, b1, t) < 0) + { + mpn_sub_n (bsm1, b1, b0, t); + MPN_ZERO (bsm1 + t, n - t); + vm1_neg ^= 1; + } + else + { + mpn_sub (bsm1, b0, n, b1, t); + } + } + + /* Compute bs2, recycling bs1. bs2=bs1+b1 */ + mpn_add (bs2, bs1, n + 1, b1, t); + + ASSERT (as1[n] <= 3); + ASSERT (bs1[n] <= 1); + ASSERT (asm1[n] <= 1); +/*ASSERT (bsm1[n] == 0);*/ + ASSERT (as2[n] <= 14); + ASSERT (bs2[n] <= 2); + +#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 + 4 * n + 4 /* Currently unused. */ + + /* vm1, 2n+1 limbs */ + TOOM42_MUL_N_REC (vm1, asm1, bsm1, n, scratch_out); + cy = 0; + if (asm1[n] != 0) + cy = mpn_add_n (vm1 + n, vm1 + n, bsm1, n); + vm1[2 * n] = cy; + + TOOM42_MUL_N_REC (v2, as2, bs2, n + 1, scratch_out); /* v2, 2n+1 limbs */ + + /* vinf, s+t limbs */ + if (s > t) mpn_mul (vinf, a3, s, b1, t); + else mpn_mul (vinf, b1, t, a3, s); + + vinf0 = vinf[0]; /* v1 overlaps with this */ + + /* v1, 2n+1 limbs */ + TOOM42_MUL_N_REC (v1, as1, bs1, n, scratch_out); + if (as1[n] == 1) + { + cy = mpn_add_n (v1 + n, v1 + n, bs1, n); + } + else if (as1[n] == 2) + { +#if HAVE_NATIVE_mpn_addlsh1_n_ip1 + cy = mpn_addlsh1_n_ip1 (v1 + n, bs1, n); +#else + cy = mpn_addmul_1 (v1 + n, bs1, n, CNST_LIMB(2)); +#endif + } + else if (as1[n] == 3) + { + cy = mpn_addmul_1 (v1 + n, bs1, n, CNST_LIMB(3)); + } + else + cy = 0; + if (bs1[n] != 0) + cy += as1[n] + mpn_add_n (v1 + n, v1 + n, as1, n); + v1[2 * n] = cy; + + TOOM42_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); + + TMP_FREE; +} -- cgit v1.2.3