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Annotation of OpenXM_contrib/gmp/mpfr/set_f.c, Revision 1.1

1.1     ! maekawa     1: /* mpfr_set_f -- set a MPFR number from a GNU MPF number
        !             2:
        !             3: Copyright (C) 1999-2000 PolKA project, Inria Lorraine and Loria
        !             4:
        !             5: This file is part of the MPFR Library.
        !             6:
        !             7: The MPFR 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 MPFR 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 MPFR 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 <stdio.h>
        !            23: #include "gmp.h"
        !            24: #include "gmp-impl.h"
        !            25: #include "longlong.h"
        !            26: #include "mpfr.h"
        !            27:
        !            28: void
        !            29: #if __STDC__
        !            30: mpfr_set_f(mpfr_ptr y, mpf_srcptr x, char rnd_mode)
        !            31: #else
        !            32: mpfr_set_f(y, x, rnd_mode)
        !            33:      mpfr_ptr y;
        !            34:      mpf_srcptr x;
        !            35:      char rnd_mode;
        !            36: #endif
        !            37: {
        !            38:   mp_limb_t *my, *mx, *tmp; unsigned long cnt, sx, sy;
        !            39:   TMP_DECL(marker);
        !            40:
        !            41:   sx = ABS(SIZ(x)); sy = ABSSIZE(y);
        !            42:   my = MANT(y); mx = MANT(x);
        !            43:
        !            44:   if (sx==0) { /* x is zero */
        !            45:     SET_ZERO(y); return;
        !            46:   }
        !            47:
        !            48:   count_leading_zeros(cnt, mx[sx - 1]);
        !            49:
        !            50:   if (SIZ(x)*SIGN(y)<0) CHANGE_SIGN(y);
        !            51:
        !            52:   if (sy < sx)
        !            53:     {
        !            54:       unsigned long xprec = sx * BITS_PER_MP_LIMB;
        !            55:
        !            56:       tmp = (mp_limb_t*) TMP_ALLOC(xprec);
        !            57:       if (cnt) mpn_lshift(tmp, mx, sx, cnt);
        !            58:       else MPN_COPY(tmp, mx, sx);
        !            59:       mpfr_round_raw(my, tmp, xprec, (SIZ(x)<0), PREC(y), rnd_mode);
        !            60:     }
        !            61:   else
        !            62:     {
        !            63:       if (cnt) mpn_lshift(my + sy - sx, mx, sx, cnt);
        !            64:       else MPN_COPY(my + sy - sx, mx, sy);
        !            65:       MPN_ZERO(my, sy - sx);
        !            66:       /* no rounding necessary, since y has a larger mantissa */
        !            67:     }
        !            68:
        !            69:   EXP(y) = EXP(x) * BITS_PER_MP_LIMB - cnt;
        !            70:
        !            71:   TMP_FREE(marker);
        !            72: }