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author | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
commit | abfbdde177c3a7155070dda1b2cdc8292054cc26 (patch) | |
tree | e021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/ieee754/dbl-64/mpn2dbl.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.bz2 |
Update.
Diffstat (limited to 'sysdeps/ieee754/dbl-64/mpn2dbl.c')
-rw-r--r-- | sysdeps/ieee754/dbl-64/mpn2dbl.c | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/mpn2dbl.c b/sysdeps/ieee754/dbl-64/mpn2dbl.c new file mode 100644 index 0000000..8145eb9 --- /dev/null +++ b/sysdeps/ieee754/dbl-64/mpn2dbl.c @@ -0,0 +1,46 @@ +/* Copyright (C) 1995, 1996, 1997 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> + +/* Convert a multi-precision integer of the needed number of bits (53 for + double) and an integral power of two to a `double' in IEEE754 double- + precision format. */ + +double +__mpn_construct_double (mp_srcptr frac_ptr, int expt, int negative) +{ + union ieee754_double u; + + u.ieee.negative = negative; + u.ieee.exponent = expt + IEEE754_DOUBLE_BIAS; +#if BITS_PER_MP_LIMB == 32 + u.ieee.mantissa1 = frac_ptr[0]; + u.ieee.mantissa0 = frac_ptr[1] & ((1 << (DBL_MANT_DIG - 32)) - 1); +#elif BITS_PER_MP_LIMB == 64 + u.ieee.mantissa1 = frac_ptr[0] & ((1L << 32) - 1); + u.ieee.mantissa0 = (frac_ptr[0] >> 32) & ((1 << (DBL_MANT_DIG - 32)) - 1); +#else + #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for" +#endif + + return u.d; +} |