Return to insert-double.c CVS log

Up to [local] / OpenXM_contrib / gmp

Annotation of OpenXM_contrib/gmp/insert-double.c, Revision 1.1

1.1     ! maekawa     1: /* __gmp_insert_double -- convert from array of mp_limb_t to double.
        !             2:
        !             3: Copyright (C) 1996 Free Software Foundation, Inc.
        !             4:
        !             5: This file is part of the GNU MP Library.
        !             6:
        !             7: The GNU MP Library is free software; you can redistribute it and/or modify
        !             8: it under the terms of the GNU Library General Public License as published by
        !             9: the Free Software Foundation; either version 2 of the License, or (at your
        !            10: option) any later version.
        !            11:
        !            12: The GNU MP Library is distributed in the hope that it will be useful, but
        !            13: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
        !            15: License for more details.
        !            16:
        !            17: You should have received a copy of the GNU Library General Public License
        !            18: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
        !            19: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
        !            20: MA 02111-1307, USA. */
        !            21:
        !            22: #include "gmp.h"
        !            23: #include "gmp-impl.h"
        !            24:
        !            25: #ifdef XDEBUG
        !            26: #undef _GMP_IEEE_FLOATS
        !            27: #endif
        !            28:
        !            29: #ifndef _GMP_IEEE_FLOATS
        !            30: #define _GMP_IEEE_FLOATS 0
        !            31: #endif
        !            32:
        !            33: double
        !            34: #if __STDC__
        !            35: __gmp_scale2 (double d, int exp)
        !            36: #else
        !            37: __gmp_scale2 (d, exp)
        !            38:      double d;
        !            39:      int exp;
        !            40: #endif
        !            41: {
        !            42: #if _GMP_IEEE_FLOATS
        !            43:   {
        !            44:     union ieee_double_extract x;
        !            45:     x.d = d;
        !            46:     x.s.exp += exp;
        !            47:     return x.d;
        !            48:   }
        !            49: #else
        !            50:   {
        !            51:     double factor, r;
        !            52:
        !            53:     factor = 2.0;
        !            54:     if (exp < 0)
        !            55:       {
        !            56:        factor = 0.5;
        !            57:        exp = -exp;
        !            58:       }
        !            59:     r = d;
        !            60:     while (exp != 0)
        !            61:       {
        !            62:        if ((exp & 1) != 0)
        !            63:          r *= factor;
        !            64:        factor *= factor;
        !            65:        exp >>= 1;
        !            66:       }
        !            67:     return r;
        !            68:   }
        !            69: #endif
        !            70: }