X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2Fgmp%2Finsert-dbl.c;fp=rts%2Fgmp%2Finsert-dbl.c;h=dc88a56f6294d588c847b3d4ef485036d8f88775;hb=0065d5ab628975892cea1ec7303f968c3338cbe1;hp=0000000000000000000000000000000000000000;hpb=28a464a75e14cece5db40f2765a29348273ff2d2;p=ghc-hetmet.git diff --git a/rts/gmp/insert-dbl.c b/rts/gmp/insert-dbl.c new file mode 100644 index 0000000..dc88a56 --- /dev/null +++ b/rts/gmp/insert-dbl.c @@ -0,0 +1,98 @@ +/* __gmp_insert_double -- convert from array of mp_limb_t to double. + +Copyright (C) 1996, 1997, 1999, 2000 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 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 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 Lesser General Public +License for more details. + +You should have received a copy of the GNU Lesser 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 + { +#if defined (__alpha) && __GNUC__ == 2 && __GNUC_MINOR__ == 8 + /* Work around alpha-specific bug in GCC 2.8.x. */ + volatile +#endif + union ieee_double_extract x; + x.d = d; + exp += x.s.exp; + x.s.exp = exp; + if (exp >= 2047) + { + /* Return +-infinity */ + x.s.exp = 2047; + x.s.manl = x.s.manh = 0; + } + else if (exp < 1) + { + x.s.exp = 1; /* smallest exponent (biased) */ + /* Divide result by 2 until we have scaled it to the right IEEE + denormalized number, but stop if it becomes zero. */ + while (exp < 1 && x.d != 0) + { + x.d *= 0.5; + exp++; + } + } + return x.d; + } +#else + { + double factor, r; + + factor = 2.0; + if (exp < 0) + { + factor = 0.5; + exp = -exp; + } + r = d; + if (exp != 0) + { + if ((exp & 1) != 0) + r *= factor; + exp >>= 1; + while (exp != 0) + { + factor *= factor; + if ((exp & 1) != 0) + r *= factor; + exp >>= 1; + } + } + return r; + } +#endif +}