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Diffstat (limited to 'contrib/libgmp/insert-double.c')
-rw-r--r-- | contrib/libgmp/insert-double.c | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/contrib/libgmp/insert-double.c b/contrib/libgmp/insert-double.c new file mode 100644 index 0000000..1ce2571 --- /dev/null +++ b/contrib/libgmp/insert-double.c @@ -0,0 +1,70 @@ +/* __gmp_insert_double -- convert from array of mp_limb_t to double. + +Copyright (C) 1996 Free Software Foundation, Inc. + +This file is part of the GNU MP Library. + +The GNU MP 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 MP 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 MP 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" + +#ifdef XDEBUG +#undef _GMP_IEEE_FLOATS +#endif + +#ifndef _GMP_IEEE_FLOATS +#define _GMP_IEEE_FLOATS 0 +#endif + +double +#if __STDC__ +__gmp_scale2 (double d, int exp) +#else +__gmp_scale2 (d, exp) + double d; + int exp; +#endif +{ +#if _GMP_IEEE_FLOATS + { + union ieee_double_extract x; + x.d = d; + x.s.exp += exp; + return x.d; + } +#else + { + double factor, r; + + factor = 2.0; + if (exp < 0) + { + factor = 0.5; + exp = -exp; + } + r = d; + while (exp != 0) + { + if ((exp & 1) != 0) + r *= factor; + factor *= factor; + exp >>= 1; + } + return r; + } +#endif +} |