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

/* mpfr_integer_p -- test if a mpfr variable is integer. | |

Copyright 2001, 2002, 2003, 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" | |

int | |

mpfr_integer_p (mpfr_srcptr x) | |

{ | |

mp_exp_t expo; | |

mp_prec_t prec; | |

mp_size_t xn; | |

mp_limb_t *xp; | |

if (MPFR_UNLIKELY( MPFR_IS_SINGULAR(x))) | |

return (MPFR_IS_ZERO(x)); | |

expo = MPFR_GET_EXP (x); | |

if (expo <= 0) | |

return 0; | |

prec = MPFR_PREC(x); | |

if ((mpfr_uexp_t) expo >= (mpfr_uexp_t) prec) | |

return 1; | |

/* 0 < expo < prec */ | |

xn = (mp_size_t) ((prec - 1) / BITS_PER_MP_LIMB); /* index of last limb */ | |

xn -= (mp_size_t) (expo / BITS_PER_MP_LIMB); | |

/* now the index of the last limb containing bits of the fractional part */ | |

xp = MPFR_MANT(x); | |

MPFR_ASSERTN(xn >= 0); | |

if (xp[xn] << (expo % BITS_PER_MP_LIMB) != 0) | |

return 0; | |

while (--xn >= 0) | |

if (xp[xn] != 0) | |

return 0; | |

return 1; | |

} |