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

/* mpfr_set -- copy of a floating-point number | |

Copyright 1999, 2001, 2002, 2003, 2004, 2005, 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" | |

/* set a to abs(b) * signb: a=b when signb = SIGN(b), a=abs(b) when signb=1 */ | |

int | |

mpfr_set4 (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode, int signb) | |

{ | |

/* Sign is ALWAYS copied */ | |

MPFR_SET_SIGN (a, signb); | |

/* Exponent is also always copied since if the number is singular, | |

the exponent field determined the number. | |

Can't use MPFR_SET_EXP since the exponent may be singular */ | |

MPFR_EXP (a) = MPFR_EXP (b); | |

if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (b))) | |

{ | |

/* MPFR_SET_NAN, MPFR_SET_ZERO and MPFR_SET_INF are useless | |

since MPFR_EXP (a) = MPFR_EXP (b) does the job */ | |

if (MPFR_IS_NAN (b)) | |

MPFR_RET_NAN; | |

else | |

MPFR_RET (0); | |

} | |

else if (MPFR_LIKELY (MPFR_PREC (b) == MPFR_PREC (a))) | |

{ | |

/* Same precision and b is not singular: | |

* just copy the mantissa, and set the exponent and the sign | |

* The result is exact. */ | |

MPN_COPY (MPFR_MANT (a), MPFR_MANT (b), | |

(MPFR_PREC (b) + BITS_PER_MP_LIMB-1)/BITS_PER_MP_LIMB); | |

MPFR_RET (0); | |

} | |

else | |

{ | |

int inex; | |

/* Else Round B inside a */ | |

MPFR_RNDRAW (inex, a, MPFR_MANT (b), MPFR_PREC (b), rnd_mode, signb, | |

if (MPFR_UNLIKELY ( ++MPFR_EXP (a) > __gmpfr_emax)) | |

return mpfr_overflow (a, rnd_mode, signb) ); | |

MPFR_RET (inex); | |

} | |

} | |

/* Set a to b */ | |

#undef mpfr_set | |

int | |

mpfr_set (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode) | |

{ | |

return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN (b)); | |

} | |

/* Set a to |b| */ | |

#undef mpfr_abs | |

int | |

mpfr_abs (mpfr_ptr a, mpfr_srcptr b, mp_rnd_t rnd_mode) | |

{ | |

return mpfr_set4 (a, b, rnd_mode, MPFR_SIGN_POS); | |

} |