sqr.c
上传用户:qaz666999
上传日期:2022-08-06
资源大小:2570k
文件大小:3k
- /* mpn_sqr -- square 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_sqr (mp_ptr p, mp_srcptr a, mp_size_t n)
- {
- ASSERT (n >= 1);
- ASSERT (! MPN_OVERLAP_P (p, 2 * n, a, n));
- if (BELOW_THRESHOLD (n, SQR_BASECASE_THRESHOLD))
- { /* mul_basecase is faster than sqr_basecase on small sizes sometimes */
- mpn_mul_basecase (p, a, n, a, n);
- }
- else if (BELOW_THRESHOLD (n, SQR_TOOM2_THRESHOLD))
- {
- mpn_sqr_basecase (p, a, n);
- }
- else if (BELOW_THRESHOLD (n, SQR_TOOM3_THRESHOLD))
- {
- /* Allocate workspace of fixed size on stack: fast! */
- mp_limb_t ws[mpn_toom2_sqr_itch (SQR_TOOM3_THRESHOLD_LIMIT-1)];
- ASSERT (SQR_TOOM3_THRESHOLD <= SQR_TOOM3_THRESHOLD_LIMIT);
- mpn_toom2_sqr (p, a, n, ws);
- }
- else if (BELOW_THRESHOLD (n, SQR_TOOM4_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom3_sqr_itch (n));
- mpn_toom3_sqr (p, a, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, SQR_TOOM6_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom4_sqr_itch (n));
- mpn_toom4_sqr (p, a, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, SQR_TOOM8_THRESHOLD))
- {
- mp_ptr ws;
- TMP_SDECL;
- TMP_SMARK;
- ws = TMP_SALLOC_LIMBS (mpn_toom6_sqr_itch (n));
- mpn_toom6_sqr (p, a, n, ws);
- TMP_SFREE;
- }
- else if (BELOW_THRESHOLD (n, SQR_FFT_THRESHOLD))
- {
- mp_ptr ws;
- TMP_DECL;
- TMP_MARK;
- ws = TMP_ALLOC_LIMBS (mpn_toom8_sqr_itch (n));
- mpn_toom8_sqr (p, a, n, ws);
- TMP_FREE;
- }
- else
- {
- /* The current FFT code allocates its own space. That should probably
- change. */
- mpn_fft_mul (p, a, n, a, n);
- }
- }