chromium / native_client / nacl-gcc / f80d6b9ee7f94755c697ffb7194fb01dd0c537dd / . / mpfr-2.4.1 / init2.c

/* mpfr_init2 -- initialize a floating-point number with given precision | |

Copyright 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" | |

void | |

mpfr_init2 (mpfr_ptr x, mp_prec_t p) | |

{ | |

mp_size_t xsize; | |

mp_ptr tmp; | |

/* Check if we can represent the number of limbs | |

* associated to the maximum of mpfr_prec_t*/ | |

MPFR_ASSERTN( MP_SIZE_T_MAX >= (MPFR_PREC_MAX/BYTES_PER_MP_LIMB) ); | |

/* Check for correct BITS_PER_MP_LIMB and BYTES_PER_MP_LIMB */ | |

MPFR_ASSERTN( BITS_PER_MP_LIMB == BYTES_PER_MP_LIMB * CHAR_BIT | |

&& sizeof(mp_limb_t) == BYTES_PER_MP_LIMB ); | |

/* Check for correct EXP NAN, ZERO & INF in both mpfr.h and in mpfr-impl.h */ | |

MPFR_ASSERTN( __MPFR_EXP_NAN == MPFR_EXP_NAN ); | |

MPFR_ASSERTN( __MPFR_EXP_ZERO == MPFR_EXP_ZERO ); | |

MPFR_ASSERTN( __MPFR_EXP_INF == MPFR_EXP_INF ); | |

MPFR_ASSERTN( MPFR_EMAX_MAX <= (MPFR_EXP_MAX >> 1) ); | |

MPFR_ASSERTN( MPFR_EMIN_MIN >= -(MPFR_EXP_MAX >> 1) ); | |

/* p=1 is not allowed since the rounding to nearest even rule requires at | |

least two bits of mantissa: the neighbours of 3/2 are 1*2^0 and 1*2^1, | |

which both have an odd mantissa */ | |

MPFR_ASSERTN(p >= MPFR_PREC_MIN && p <= MPFR_PREC_MAX); | |

xsize = (mp_size_t) ((p - 1) / BITS_PER_MP_LIMB) + 1; | |

tmp = (mp_ptr) (*__gmp_allocate_func)(MPFR_MALLOC_SIZE(xsize)); | |

MPFR_PREC(x) = p; /* Set prec */ | |

MPFR_EXP (x) = MPFR_EXP_INVALID; /* make sure that the exp field has a | |

valid value in the C point of view */ | |

MPFR_SET_POS(x); /* Set a sign */ | |

MPFR_SET_MANT_PTR(x, tmp); /* Set Mantissa ptr */ | |

MPFR_SET_ALLOC_SIZE(x, xsize); /* Fix alloc size of Mantissa */ | |

MPFR_SET_NAN(x); /* initializes to NaN */ | |

} | |

#ifdef MPFR_USE_OWN_MPFR_TMP_ALLOC | |

static unsigned char mpfr_stack_tab[8000000]; | |

unsigned char *mpfr_stack = mpfr_stack_tab; | |

#endif |