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

/* mpfr_reldiff -- compute relative difference of two floating-point numbers. | |

Copyright 2000, 2001, 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" | |

/* reldiff(b, c) = abs(b-c)/b */ | |

void | |

mpfr_reldiff (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode) | |

{ | |

mpfr_t b_copy; | |

if (MPFR_ARE_SINGULAR (b, c)) | |

{ | |

if (MPFR_IS_NAN(b) || MPFR_IS_NAN(c)) | |

{ | |

MPFR_SET_NAN(a); | |

return; | |

} | |

else if (MPFR_IS_INF(b)) | |

{ | |

if (MPFR_IS_INF (c) && (MPFR_SIGN (c) == MPFR_SIGN (b))) | |

MPFR_SET_ZERO(a); | |

else | |

MPFR_SET_NAN(a); | |

return; | |

} | |

else if (MPFR_IS_INF(c)) | |

{ | |

MPFR_SET_SAME_SIGN (a, b); | |

MPFR_SET_INF (a); | |

return; | |

} | |

else if (MPFR_IS_ZERO(b)) /* reldiff = abs(c)/c = sign(c) */ | |

{ | |

mpfr_set_si (a, MPFR_INT_SIGN (c), rnd_mode); | |

return; | |

} | |

/* Fall through */ | |

} | |

if (a == b) | |

{ | |

mpfr_init2 (b_copy, MPFR_PREC(b)); | |

mpfr_set (b_copy, b, GMP_RNDN); | |

} | |

mpfr_sub (a, b, c, rnd_mode); | |

mpfr_abs (a, a, rnd_mode); /* for compatibility with MPF */ | |

mpfr_div (a, a, (a == b) ? b_copy : b, rnd_mode); | |

if (a == b) | |

mpfr_clear (b_copy); | |

} |