mirror of
https://github.com/vale981/arb
synced 2025-03-06 01:41:39 -05:00
85 lines
2.2 KiB
C
85 lines
2.2 KiB
C
/*=============================================================================
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This file is part of ARB.
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ARB 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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ARB 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 ARB; 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) 2012 Fredrik Johansson
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******************************************************************************/
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#include "fmpr.h"
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static mpfr_rnd_t fmpr_rnd_to_mpfr(fmpr_rnd_t rnd)
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{
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if (rnd == FMPR_RND_NEAR) return MPFR_RNDN;
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if (rnd == FMPR_RND_FLOOR) return MPFR_RNDD;
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if (rnd == FMPR_RND_CEIL) return MPFR_RNDU;
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if (rnd == FMPR_RND_DOWN) return MPFR_RNDZ;
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if (rnd == FMPR_RND_UP) return MPFR_RNDA;
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abort();
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}
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long
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fmpr_log(fmpr_t y, const fmpr_t x, long prec, fmpr_rnd_t rnd)
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{
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if (fmpr_is_special(x))
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{
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if (fmpr_is_zero(x))
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fmpr_neg_inf(y);
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else if (fmpr_is_pos_inf(x))
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fmpr_pos_inf(y);
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else
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fmpr_nan(y);
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return FMPR_RESULT_EXACT;
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}
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if (fmpr_sgn(x) < 0)
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{
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fmpr_nan(y);
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return FMPR_RESULT_EXACT;
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}
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if (fmpr_is_one(x))
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{
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fmpr_zero(y);
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return FMPR_RESULT_EXACT;
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}
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{
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mpfr_t t, u;
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long r;
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mpfr_init2(t, 1 + fmpz_bits(fmpr_manref(x)));
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mpfr_init2(u, FLINT_MAX(2, prec));
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fmpr_get_mpfr(t, x, MPFR_RNDD);
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mpfr_log(u, t, fmpr_rnd_to_mpfr(rnd));
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fmpr_set_mpfr(y, u);
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r = prec - fmpz_bits(fmpr_manref(y));
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mpfr_clear(t);
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mpfr_clear(u);
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return r;
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}
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}
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