X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=gmp%2Fmpn%2Fgeneric%2Ftoom3_sqr.c;fp=gmp%2Fmpn%2Fgeneric%2Ftoom3_sqr.c;h=0c8a4ff74db2db12b55b486207f21a31c4fd6c80;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git diff --git a/gmp/mpn/generic/toom3_sqr.c b/gmp/mpn/generic/toom3_sqr.c new file mode 100644 index 00000000..0c8a4ff7 --- /dev/null +++ b/gmp/mpn/generic/toom3_sqr.c @@ -0,0 +1,219 @@ +/* mpn_toom3_sqr -- Square {ap,an}. + + Contributed to the GNU project by Torbjorn Granlund. + + 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/. */ + + +/* + Things to work on: + + 1. Trim allocation. The allocations for as1 and asm1 could be + avoided by instead reusing the pp area and the scratch area. + 2. Use new toom functions for the recursive calls. +*/ + +#include "gmp.h" +#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)*(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_sqr_basecase 1 +#define MAYBE_sqr_toom3 1 +#else +#define MAYBE_sqr_basecase \ + (SQR_TOOM3_THRESHOLD < 3 * SQR_KARATSUBA_THRESHOLD) +#define MAYBE_sqr_toom3 \ + (SQR_TOOM4_THRESHOLD >= 3 * SQR_TOOM3_THRESHOLD) +#endif + +#define TOOM3_SQR_N_REC(p, a, n, ws) \ + do { \ + if (MAYBE_sqr_basecase \ + && BELOW_THRESHOLD (n, SQR_KARATSUBA_THRESHOLD)) \ + mpn_sqr_basecase (p, a, n); \ + else if (! MAYBE_sqr_toom3 \ + || BELOW_THRESHOLD (n, SQR_TOOM3_THRESHOLD)) \ + mpn_kara_sqr_n (p, a, n, ws); \ + else \ + mpn_toom3_sqr_n (p, a, n, ws); \ + } while (0) + +void +mpn_toom3_sqr (mp_ptr pp, + mp_srcptr ap, mp_size_t an, + mp_ptr scratch) +{ + mp_size_t n, s; + mp_limb_t cy, vinf0; + mp_ptr gp; + mp_ptr as1, asm1, as2; + TMP_DECL; + +#define a0 ap +#define a1 (ap + n) +#define a2 (ap + 2*n) + + n = (an + 2) / (size_t) 3; + + s = an - 2 * n; + + ASSERT (0 < s && s <= n); + + TMP_MARK; + + as1 = TMP_SALLOC_LIMBS (n + 1); + asm1 = TMP_SALLOC_LIMBS (n + 1); + as2 = TMP_SALLOC_LIMBS (n + 1); + + gp = pp; + + /* Compute as1 and asm1. */ + cy = mpn_add (gp, a0, n, a2, s); +#if HAVE_NATIVE_mpn_addsub_n + if (cy == 0 && mpn_cmp (gp, a1, n) < 0) + { + cy = mpn_addsub_n (as1, asm1, a1, gp, n); + as1[n] = 0; + asm1[n] = 0; + } + else + { + cy2 = mpn_addsub_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; + } + else + { + cy -= mpn_sub_n (asm1, gp, a1, n); + asm1[n] = cy; + } +#endif + + /* Compute as2. */ +#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_lshift (as2, a2, s, 1); + cy += mpn_add_n (as2, a1, as2, s); + if (s != n) + cy = mpn_add_1 (as2 + s, a1 + s, n - s, cy); + cy = 2 * cy + mpn_lshift (as2, as2, n, 1); + cy += mpn_add_n (as2, a0, as2, n); +#endif + as2[n] = cy; + + ASSERT (as1[n] <= 2); + ASSERT (asm1[n] <= 1); + +#define v0 pp /* 2n */ +#define v1 (pp + 2 * n) /* 2n+1 */ +#define vinf (pp + 4 * n) /* s+s */ +#define vm1 scratch /* 2n+1 */ +#define v2 (scratch + 2 * n + 1) /* 2n+2 */ +#define scratch_out (scratch + 4 * n + 4) + + /* vm1, 2n+1 limbs */ +#ifdef SMALLER_RECURSION + TOOM3_SQR_N_REC (vm1, asm1, n, scratch_out); + cy = 0; + if (asm1[n] != 0) + cy = asm1[n] + mpn_add_n (vm1 + n, vm1 + n, asm1, n); + if (asm1[n] != 0) + cy += mpn_add_n (vm1 + n, vm1 + n, asm1, n); + vm1[2 * n] = cy; +#else + TOOM3_SQR_N_REC (vm1, asm1, n + 1, scratch_out); +#endif + + TOOM3_SQR_N_REC (v2, as2, n + 1, scratch_out); /* v2, 2n+1 limbs */ + + TOOM3_SQR_N_REC (vinf, a2, s, scratch_out); /* vinf, s+s limbs */ + + vinf0 = vinf[0]; /* v1 overlaps with this */ + +#ifdef SMALLER_RECURSION + /* v1, 2n+1 limbs */ + TOOM3_SQR_N_REC (v1, as1, n, scratch_out); + if (as1[n] == 1) + { + cy = as1[n] + mpn_add_n (v1 + n, v1 + n, as1, n); + } + else if (as1[n] != 0) + { +#if HAVE_NATIVE_mpn_addlsh1_n + cy = 2 * as1[n] + mpn_addlsh1_n (v1 + n, v1 + n, as1, n); +#else + cy = 2 * as1[n] + mpn_addmul_1 (v1 + n, as1, n, CNST_LIMB(2)); +#endif + } + else + cy = 0; + if (as1[n] == 1) + { + cy += mpn_add_n (v1 + n, v1 + n, as1, n); + } + else if (as1[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]; + TOOM3_SQR_N_REC (v1, as1, n + 1, scratch_out); + vinf[1] = cy; +#endif + + TOOM3_SQR_N_REC (v0, ap, n, scratch_out); /* v0, 2n limbs */ + + mpn_toom_interpolate_5pts (pp, v2, vm1, n, s + s, 1, vinf0, scratch_out); + + TMP_FREE; +}