Return to set_ui.c CVS log

Up to [local] / OpenXM_contrib / gmp / mpfr

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

1.1     ! ohara       1: /* mpfr_set_ui -- set a MPFR number from a machine unsigned integer
        !             2:
        !             3: Copyright 1999, 2000, 2001 Free Software Foundation.
        !             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 Lesser General Public License as published by
        !             9: the Free Software Foundation; either version 2.1 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 Lesser General Public
        !            15: License for more details.
        !            16:
        !            17: You should have received a copy of the GNU Lesser 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 "gmp.h"
        !            23: #include "gmp-impl.h"
        !            24: #include "longlong.h"
        !            25: #include "mpfr.h"
        !            26: #include "mpfr-impl.h"
        !            27:
        !            28: int
        !            29: mpfr_set_ui (mpfr_ptr x, unsigned long i, mp_rnd_t rnd_mode)
        !            30: {
        !            31:   int inex = 0;
        !            32:
        !            33:   MPFR_CLEAR_FLAGS(x);
        !            34:   if (i == 0)
        !            35:     MPFR_SET_ZERO(x);  /* the sign will be set later */
        !            36:   else
        !            37:     {
        !            38:       mp_size_t xn;
        !            39:       unsigned int cnt, nbits;
        !            40:       mp_limb_t *xp;
        !            41:
        !            42:       xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
        !            43:       count_leading_zeros(cnt, (mp_limb_t) i);
        !            44:
        !            45:       xp = MPFR_MANT(x);
        !            46:       xp[xn] = ((mp_limb_t) i) << cnt;
        !            47:       /* don't forget to put zero in lower limbs */
        !            48:       MPN_ZERO(xp, xn);
        !            49:
        !            50:       MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt;
        !            51:       inex = mpfr_check_range(x, rnd_mode);
        !            52:       if (inex)
        !            53:         return inex; /* underflow or overflow */
        !            54:
        !            55:       /* round if MPFR_PREC(x) smaller than length of i */
        !            56:       if (MPFR_PREC(x) < nbits)
        !            57:         {
        !            58:           int carry;
        !            59:           carry = mpfr_round_raw(xp+xn, xp+xn, nbits, 0, MPFR_PREC(x),
        !            60:                                  rnd_mode, &inex);
        !            61:           if (carry)
        !            62:             {
        !            63:               mp_exp_t exp = MPFR_EXP(x);
        !            64:
        !            65:               if (exp == __mpfr_emax)
        !            66:                 return mpfr_set_overflow(x, rnd_mode, 1);
        !            67:
        !            68:               MPFR_EXP(x)++;
        !            69:               xp[xn] = GMP_LIMB_HIGHBIT;
        !            70:             }
        !            71:         }
        !            72:     }
        !            73:
        !            74:   MPFR_SET_POS(x);
        !            75:
        !            76:   MPFR_RET(inex);
        !            77: }