68 lines
1.8 KiB
C
68 lines
1.8 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 <gmp.h>
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#include "flint.h"
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#include "ulong_extras.h"
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#include "fmpz.h"
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#if FLINT64 /* 2^53 */
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#define DOUBLE_MAX WORD(9007199254740992)
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#define DOUBLE_MIN WORD(-9007199254740992)
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#else
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#define DOUBLE_MAX COEFF_MAX
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#define DOUBLE_MIN COEFF_MIN
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#endif
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extern double __gmpn_get_d(mp_limb_t *, size_t, size_t, slong);
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double
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fmpz_get_d(const fmpz_t f)
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{
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fmpz c = *f;
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if (c >= DOUBLE_MIN && c <= DOUBLE_MAX)
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{
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return (double) c;
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}
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else if (!COEFF_IS_MPZ(c))
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{
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mp_limb_t d;
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if (c > 0)
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{
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d = c;
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return __gmpn_get_d(&d, 1, 1, 0);
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}
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else
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{
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d = -c;
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return __gmpn_get_d(&d, 1, -1, 0);
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}
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}
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else
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return mpz_get_d(COEFF_TO_PTR(c));
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}
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