1*f357360cSJérôme Duval /* Copyright (C) 1995,1996,1997,1998,2002,2003 Free Software Foundation, Inc.
2*f357360cSJérôme Duval This file is part of the GNU C Library.
3*f357360cSJérôme Duval
4*f357360cSJérôme Duval The GNU C Library is free software; you can redistribute it and/or
5*f357360cSJérôme Duval modify it under the terms of the GNU Lesser General Public
6*f357360cSJérôme Duval License as published by the Free Software Foundation; either
7*f357360cSJérôme Duval version 2.1 of the License, or (at your option) any later version.
8*f357360cSJérôme Duval
9*f357360cSJérôme Duval The GNU C Library is distributed in the hope that it will be useful,
10*f357360cSJérôme Duval but WITHOUT ANY WARRANTY; without even the implied warranty of
11*f357360cSJérôme Duval MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12*f357360cSJérôme Duval Lesser General Public License for more details.
13*f357360cSJérôme Duval
14*f357360cSJérôme Duval You should have received a copy of the GNU Lesser General Public
15*f357360cSJérôme Duval License along with the GNU C Library; if not, write to the Free
16*f357360cSJérôme Duval Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
17*f357360cSJérôme Duval 02111-1307 USA. */
18*f357360cSJérôme Duval
19*f357360cSJérôme Duval #include "gmp.h"
20*f357360cSJérôme Duval #include "gmp-impl.h"
21*f357360cSJérôme Duval #include <ieee754.h>
22*f357360cSJérôme Duval #include <float.h>
23*f357360cSJérôme Duval #include <math.h>
24*f357360cSJérôme Duval
25*f357360cSJérôme Duval /* Convert a multi-precision integer of the needed number of bits (64 for
26*f357360cSJérôme Duval long double) and an integral power of two to a `long double' in IEEE854
27*f357360cSJérôme Duval extended-precision format. */
28*f357360cSJérôme Duval
29*f357360cSJérôme Duval long double
__mpn_construct_long_double(mp_srcptr frac_ptr,int expt,int sign)30*f357360cSJérôme Duval __mpn_construct_long_double (mp_srcptr frac_ptr, int expt, int sign)
31*f357360cSJérôme Duval {
32*f357360cSJérôme Duval union ieee854_long_double u;
33*f357360cSJérôme Duval
34*f357360cSJérôme Duval u.ieee.negative = sign;
35*f357360cSJérôme Duval u.ieee.exponent = expt + IEEE854_LONG_DOUBLE_BIAS;
36*f357360cSJérôme Duval #if BITS_PER_MP_LIMB == 32
37*f357360cSJérôme Duval u.ieee.mantissa1 = frac_ptr[0];
38*f357360cSJérôme Duval u.ieee.mantissa0 = frac_ptr[1];
39*f357360cSJérôme Duval #elif BITS_PER_MP_LIMB == 64
40*f357360cSJérôme Duval u.ieee.mantissa1 = frac_ptr[0] & (((mp_limb_t) 1 << 32) - 1);
41*f357360cSJérôme Duval u.ieee.mantissa0 = frac_ptr[0] >> 32;
42*f357360cSJérôme Duval #else
43*f357360cSJérôme Duval #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
44*f357360cSJérôme Duval #endif
45*f357360cSJérôme Duval
46*f357360cSJérôme Duval return u.d;
47*f357360cSJérôme Duval }
48