diff options
Diffstat (limited to 'sysdeps/ieee754/ldbl-128/mpn2ldbl.c')
-rw-r--r-- | sysdeps/ieee754/ldbl-128/mpn2ldbl.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/sysdeps/ieee754/ldbl-128/mpn2ldbl.c b/sysdeps/ieee754/ldbl-128/mpn2ldbl.c new file mode 100644 index 0000000..d9cc452 --- /dev/null +++ b/sysdeps/ieee754/ldbl-128/mpn2ldbl.c @@ -0,0 +1,51 @@ +/* Copyright (C) 1995, 1996, 1997, 1998, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "gmp.h" +#include "gmp-impl.h" +#include <ieee754.h> +#include <float.h> +#include <math.h> + +/* Convert a multi-precision integer of the needed number of bits (113 for + long double) and an integral power of two to a `long double' in IEEE854 + quad-precision format. */ + +long double +__mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign) +{ + union ieee854_long_double u; + + u.ieee.negative = sign; + u.ieee.exponent = expt + IEEE854_LONG_DOUBLE_BIAS; +#if BITS_PER_MP_LIMB == 32 + u.ieee.mantissa3 = frac_ptr[0]; + u.ieee.mantissa2 = frac_ptr[1]; + u.ieee.mantissa1 = frac_ptr[2]; + u.ieee.mantissa0 = frac_ptr[3] & ((1 << (LDBL_MANT_DIG - 96)) - 1); +#elif BITS_PER_MP_LIMB == 64 + u.ieee.mantissa3 = frac_ptr[0] & ((1L << 32) - 1); + u.ieee.mantissa2 = frac_ptr[0] >> 32; + u.ieee.mantissa1 = frac_ptr[1] & ((1L << 32) - 1); + u.ieee.mantissa0 = (frac_ptr[1] >> 32) & ((1 << (LDBL_MANT_DIG - 96)) - 1); +#else + #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for" +#endif + + return u.d; +} |