xref: /dflybsd-src/contrib/gmp/mpf/random2.c (revision 86d7f5d305c6adaa56ff4582ece9859d73106103)
186d7f5d3SJohn Marino /* mpf_random2 -- Generate a positive random mpf_t of specified size, with
286d7f5d3SJohn Marino    long runs of consecutive ones and zeros in the binary representation.
386d7f5d3SJohn Marino    Intended for testing of other MP routines.
486d7f5d3SJohn Marino 
586d7f5d3SJohn Marino Copyright 1995, 1996, 2001, 2002, 2003 Free Software Foundation, Inc.
686d7f5d3SJohn Marino 
786d7f5d3SJohn Marino This file is part of the GNU MP Library.
886d7f5d3SJohn Marino 
986d7f5d3SJohn Marino The GNU MP Library is free software; you can redistribute it and/or modify
1086d7f5d3SJohn Marino it under the terms of the GNU Lesser General Public License as published by
1186d7f5d3SJohn Marino the Free Software Foundation; either version 3 of the License, or (at your
1286d7f5d3SJohn Marino option) any later version.
1386d7f5d3SJohn Marino 
1486d7f5d3SJohn Marino The GNU MP Library is distributed in the hope that it will be useful, but
1586d7f5d3SJohn Marino WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1686d7f5d3SJohn Marino or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1786d7f5d3SJohn Marino License for more details.
1886d7f5d3SJohn Marino 
1986d7f5d3SJohn Marino You should have received a copy of the GNU Lesser General Public License
2086d7f5d3SJohn Marino along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
2186d7f5d3SJohn Marino 
2286d7f5d3SJohn Marino #include "gmp.h"
2386d7f5d3SJohn Marino #include "gmp-impl.h"
2486d7f5d3SJohn Marino 
2586d7f5d3SJohn Marino 
2686d7f5d3SJohn Marino void
mpf_random2(mpf_ptr x,mp_size_t xs,mp_exp_t exp)2786d7f5d3SJohn Marino mpf_random2 (mpf_ptr x, mp_size_t xs, mp_exp_t exp)
2886d7f5d3SJohn Marino {
2986d7f5d3SJohn Marino   mp_size_t xn;
3086d7f5d3SJohn Marino   mp_size_t prec;
3186d7f5d3SJohn Marino   mp_limb_t elimb;
3286d7f5d3SJohn Marino 
3386d7f5d3SJohn Marino   xn = ABS (xs);
3486d7f5d3SJohn Marino   prec = PREC(x);
3586d7f5d3SJohn Marino 
3686d7f5d3SJohn Marino   if (xn == 0)
3786d7f5d3SJohn Marino     {
3886d7f5d3SJohn Marino       EXP(x) = 0;
3986d7f5d3SJohn Marino       SIZ(x) = 0;
4086d7f5d3SJohn Marino       return;
4186d7f5d3SJohn Marino     }
4286d7f5d3SJohn Marino 
4386d7f5d3SJohn Marino   if (xn > prec + 1)
4486d7f5d3SJohn Marino     xn = prec + 1;
4586d7f5d3SJohn Marino 
4686d7f5d3SJohn Marino   /* General random mantissa.  */
4786d7f5d3SJohn Marino   mpn_random2 (PTR(x), xn);
4886d7f5d3SJohn Marino 
4986d7f5d3SJohn Marino   /* Generate random exponent.  */
5086d7f5d3SJohn Marino   _gmp_rand (&elimb, RANDS, GMP_NUMB_BITS);
5186d7f5d3SJohn Marino   exp = ABS (exp);
5286d7f5d3SJohn Marino   exp = elimb % (2 * exp + 1) - exp;
5386d7f5d3SJohn Marino 
5486d7f5d3SJohn Marino   EXP(x) = exp;
5586d7f5d3SJohn Marino   SIZ(x) = xs < 0 ? -xn : xn;
5686d7f5d3SJohn Marino }
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