81 lines
3.1 KiB
C
81 lines
3.1 KiB
C
/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2011 Fredrik Johansson
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******************************************************************************/
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#include "arith.h"
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#define BERNOULLI_DENOM_MAX_SMALL 178
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#if FLINT64
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#define __u32 unsigned int
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#else
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#define __u32 mp_limb_t
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#endif
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static const __u32 __bernoulli_denom_small[] =
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{
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UWORD(1), UWORD(6), UWORD(30), UWORD(42), UWORD(30), UWORD(66), UWORD(2730), UWORD(6), UWORD(510), UWORD(798), UWORD(330),
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UWORD(138), UWORD(2730), UWORD(6), UWORD(870), UWORD(14322), UWORD(510), UWORD(6), UWORD(1919190), UWORD(6), UWORD(13530),
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UWORD(1806), UWORD(690), UWORD(282), UWORD(46410), UWORD(66), UWORD(1590), UWORD(798), UWORD(870), UWORD(354),
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UWORD(56786730), UWORD(6), UWORD(510), UWORD(64722), UWORD(30), UWORD(4686), UWORD(140100870), UWORD(6), UWORD(30),
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UWORD(3318), UWORD(230010), UWORD(498), UWORD(3404310), UWORD(6), UWORD(61410), UWORD(272118), UWORD(1410), UWORD(6),
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UWORD(4501770), UWORD(6), UWORD(33330), UWORD(4326), UWORD(1590), UWORD(642), UWORD(209191710), UWORD(1518),
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UWORD(1671270), UWORD(42), UWORD(1770), UWORD(6), UWORD(2328255930), UWORD(6), UWORD(30), UWORD(4357878), UWORD(510),
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UWORD(8646), UWORD(4206930), UWORD(6), UWORD(4110), UWORD(274386), UWORD(679470), UWORD(6), UWORD(2381714790),
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UWORD(6), UWORD(4470), UWORD(2162622), UWORD(30), UWORD(138), UWORD(1794590070), UWORD(6), UWORD(230010),
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UWORD(130074), UWORD(2490), UWORD(1002), UWORD(3404310), UWORD(66), UWORD(5190), UWORD(2478), UWORD(1043970),
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UWORD(1074),
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};
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void arith_bernoulli_number_denom(fmpz_t den, ulong n)
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{
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slong i;
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mp_limb_t p;
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const mp_limb_t * primes;
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if (n % 2 == 1)
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{
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fmpz_set_ui(den, 1 + (n == 1));
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}
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else if (n <= BERNOULLI_DENOM_MAX_SMALL)
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{
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fmpz_set_ui(den, __bernoulli_denom_small[n / 2]);
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}
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else
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{
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n_prime_pi_bounds(&p, &p, n);
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primes = n_primes_arr_readonly(p + 1);
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fmpz_set_ui(den, UWORD(6));
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for (i = 2; i < n; i++)
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{
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p = primes[i];
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if (p - 1 > n)
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break;
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if (n % (p - 1) == 0)
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fmpz_mul_ui(den, den, p);
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}
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}
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}
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