Blame mpf/random2.c

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/* mpf_random2 -- Generate a positive random mpf_t of specified size, with
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   long runs of consecutive ones and zeros in the binary representation.
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   Intended for testing of other MP routines.
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Copyright 1995, 1996, 2001-2003 Free Software Foundation, Inc.
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This file is part of the GNU MP Library.
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The GNU MP Library is free software; you can redistribute it and/or modify
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it under the terms of either:
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  * the GNU Lesser General Public License as published by the Free
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    Software Foundation; either version 3 of the License, or (at your
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    option) any later version.
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or
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  * the GNU General Public License as published by the Free Software
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    Foundation; either version 2 of the License, or (at your option) any
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    later version.
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or both in parallel, as here.
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The GNU MP Library is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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for more details.
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You should have received copies of the GNU General Public License and the
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GNU Lesser General Public License along with the GNU MP Library.  If not,
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see https://www.gnu.org/licenses/.  */
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#include "gmp.h"
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#include "gmp-impl.h"
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void
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mpf_random2 (mpf_ptr x, mp_size_t xs, mp_exp_t exp)
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{
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  mp_size_t xn;
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  mp_size_t prec;
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  mp_limb_t elimb;
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  xn = ABS (xs);
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  prec = PREC(x);
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  if (xn == 0)
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    {
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      EXP(x) = 0;
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      SIZ(x) = 0;
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      return;
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    }
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  if (xn > prec + 1)
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    xn = prec + 1;
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  /* General random mantissa.  */
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  mpn_random2 (PTR(x), xn);
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  /* Generate random exponent.  */
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  _gmp_rand (&elimb, RANDS, GMP_NUMB_BITS);
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  exp = ABS (exp);
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  exp = elimb % (2 * exp + 1) - exp;
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  EXP(x) = exp;
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  SIZ(x) = xs < 0 ? -xn : xn;
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}