/* mpz_set_d(integer, val) -- Assign INTEGER with a double value VAL.

Copyright 1995, 1996, 2000-2003, 2006 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify

it under the terms of either:

  * the GNU Lesser General Public License as published by the Free

    Software Foundation; either version 3 of the License, or (at your

    option) any later version.

or

  * the GNU General Public License as published by the Free Software

    Foundation; either version 2 of the License, or (at your option) any

    later version.

or both in parallel, as here.

The GNU MP Library is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY

or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

You should have received copies of the GNU General Public License and the

GNU Lesser General Public License along with the GNU MP Library.  If not,

see https://www.gnu.org/licenses/.  */

#include "config.h"

#if HAVE_FLOAT_H

#include <float.h>  /* for DBL_MAX */

#endif

#include "gmp.h"

#include "gmp-impl.h"

/* We used to have a special case for d < MP_BASE_AS_DOUBLE, just casting

   double -> limb.  Unfortunately gcc 3.3 on powerpc970-apple-darwin6.8.5

   got this wrong.  (It assumed __fixunsdfdi returned its result in a single

   64-bit register, where instead that function followed the calling

   conventions and gave the result in two parts r3 and r4.)  Hence the use

   of __gmp_extract_double in all cases.  */

void

mpz_set_d (mpz_ptr r, double d)

{

  int negative;

  mp_limb_t tp[LIMBS_PER_DOUBLE];

  mp_ptr rp;

  mp_size_t rn;

  DOUBLE_NAN_INF_ACTION (d,

			 __gmp_invalid_operation (),

			 __gmp_invalid_operation ());

  negative = d < 0;

  d = ABS (d);

  rn = __gmp_extract_double (tp, d);

  if (ALLOC(r) < rn)

    _mpz_realloc (r, rn);

  if (rn <= 0)

    rn = 0;

  rp = PTR (r);

  switch (rn)

    {

    default:

      MPN_ZERO (rp, rn - LIMBS_PER_DOUBLE);

      rp += rn - LIMBS_PER_DOUBLE;

      /* fall through */

#if LIMBS_PER_DOUBLE == 2

    case 2:

      rp[1] = tp[1], rp[0] = tp[0];

      break;

    case 1:

      rp[0] = tp[1];

      break;

#endif

#if LIMBS_PER_DOUBLE == 3

    case 3:

      rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];

      break;

    case 2:

      rp[1] = tp[2], rp[0] = tp[1];

      break;

    case 1:

      rp[0] = tp[2];

      break;

#endif

#if LIMBS_PER_DOUBLE == 4

    case 4:

      rp[3] = tp[3], rp[2] = tp[2], rp[1] = tp[1], rp[0] = tp[0];

      break;

    case 3:

      rp[2] = tp[3], rp[1] = tp[2], rp[0] = tp[1];

      break;

    case 2:

      rp[1] = tp[3], rp[0] = tp[2];

      break;

    case 1:

      rp[0] = tp[3];

      break;

#endif

    case 0:

      break;

    }

  SIZ(r) = negative ? -rn : rn;

}