mul_n.c
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上传日期:2022-08-06
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- /* mpn_mul_n -- multiply natural numbers.
- Copyright 1991, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
- 2005, 2008, 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 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"
- #include "longlong.h"
- void
- mpn_mul_n (mp_ptr p, mp_srcptr a, mp_srcptr b, mp_size_t n)
- {
- ASSERT (n >= 1);
- ASSERT (! MPN_OVERLAP_P (p, 2 * n, a, n));
- ASSERT (! MPN_OVERLAP_P (p, 2 * n, b, n));
- if (BELOW_THRESHOLD (n, MUL_TOOM22_THRESHOLD))
- {
- mpn_mul_basecase (p, a, n, b, n);
- }
- else if (BELOW_THRESHOLD (n, MUL_TOOM33_THRESHOLD))
- {
- /* Allocate workspace of fixed size on stack: fast! */
- mp_limb_t ws[mpn_toom22_mul_itch (MUL_TOOM33_THRESHOLD_LIMIT-1,
- MUL_TOOM33_THRESHOLD_LIMIT-1)];
- ASSERT (MUL_TOOM33_THRESHOLD <= MUL_TOOM33_THRESHOLD_LIMIT);
- mpn_toom22_mul (p, a, n, b, n, ws);
- }
- else if (BELOW_THRESHOLD (n, MUL_TOOM44_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom33_mul_itch (n, n));
- mpn_toom33_mul (p, a, n, b, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, MUL_TOOM6H_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom44_mul_itch (n, n));
- mpn_toom44_mul (p, a, n, b, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, MUL_TOOM8H_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom6_mul_n_itch (n));
- mpn_toom6h_mul (p, a, n, b, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, MUL_FFT_THRESHOLD))
- {
- mp_ptr ws;
- TMP_DECL;
- TMP_MARK;
- ws = TMP_ALLOC_LIMBS (mpn_toom8_mul_n_itch (n));
- mpn_toom8h_mul (p, a, n, b, n, ws);
- TMP_FREE;
- }
- else
- {
- /* The current FFT code allocates its own space. That should probably
- change. */
- mpn_fft_mul (p, a, n, b, n);
- }
- }