chromium / native_client / nacl-gcc / f80d6b9ee7f94755c697ffb7194fb01dd0c537dd / . / mpfr-2.4.1 / get_z.c

/* mpfr_get_z_exp -- get a multiple-precision integer from | |

a floating-point number | |

Copyright 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. | |

Contributed by the Arenaire and Cacao projects, INRIA. | |

This file is part of the GNU MPFR Library. | |

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

it under the terms of the GNU Lesser General Public License as published by | |

the Free Software Foundation; either version 2.1 of the License, or (at your | |

option) any later version. | |

The GNU MPFR 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 Lesser General Public | |

License for more details. | |

You should have received a copy of the GNU Lesser General Public License | |

along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to | |

the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, | |

MA 02110-1301, USA. */ | |

#include "mpfr-impl.h" | |

void | |

mpfr_get_z (mpz_ptr z, mpfr_srcptr f, mp_rnd_t rnd) | |

{ | |

mpfr_t r; | |

mp_exp_t exp = MPFR_EXP (f); | |

/* if exp <= 0, then |f|<1, thus |o(f)|<=1 */ | |

MPFR_ASSERTD (MPFR_PREC_MIN == 2); | |

mpfr_init2 (r, (exp <= 0) ? MPFR_PREC_MIN : exp + 1); | |

mpfr_rint (r, f, rnd); | |

MPFR_ASSERTN (MPFR_IS_FP (r) ); | |

exp = mpfr_get_z_exp (z, r); | |

/* FIXME: It seems that exp < 0 is always true */ | |

if (exp >= 0) | |

mpz_mul_2exp (z, z, exp); | |

else | |

mpz_div_2exp (z, z, -exp); | |

mpfr_clear (r); | |

} |