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Annotation of OpenXM_contrib/gmp/mpfr/set_si.c, Revision 1.1.1.2

1.1.1.2 ! ohara       1: /* mpfr_set_si -- set a MPFR number from a machine signed integer
1.1       maekawa     2:
1.1.1.2 ! ohara       3: Copyright 1999, 2000, 2001 Free Software Foundation.
1.1       maekawa     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
1.1.1.2 ! ohara       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
1.1       maekawa    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
1.1.1.2 ! ohara      14: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    15: License for more details.
                     16:
1.1.1.2 ! ohara      17: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    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"
1.1.1.2 ! ohara      26: #include "mpfr-impl.h"
1.1       maekawa    27:
1.1.1.2 ! ohara      28: int
        !            29: mpfr_set_si (mpfr_ptr x, long i, mp_rnd_t rnd_mode)
1.1       maekawa    30: {
1.1.1.2 ! ohara      31:   int inex;
        !            32:   mp_size_t xn;
        !            33:   unsigned int cnt, nbits;
        !            34:   mp_limb_t ai, *xp;
        !            35:
        !            36:   MPFR_CLEAR_FLAGS(x);
        !            37:   if (i == 0)
        !            38:     {
        !            39:       MPFR_SET_ZERO(x);
        !            40:       MPFR_SET_POS(x);
        !            41:       MPFR_RET(0);
        !            42:     }
        !            43:
        !            44:   xn = (MPFR_PREC(x)-1)/BITS_PER_MP_LIMB;
        !            45:   ai = SAFE_ABS(long, i);
        !            46:   count_leading_zeros(cnt, ai);
1.1       maekawa    47:
1.1.1.2 ! ohara      48:   xp = MPFR_MANT(x);
        !            49:   xp[xn] = ai << cnt;
1.1       maekawa    50:   /* don't forget to put zero in lower limbs */
1.1.1.2 ! ohara      51:   MPN_ZERO(xp, xn);
        !            52:   /* set sign */
        !            53:   if ((i < 0) ^ (MPFR_SIGN(x) < 0))
        !            54:     MPFR_CHANGE_SIGN(x);
        !            55:
        !            56:   MPFR_EXP(x) = nbits = BITS_PER_MP_LIMB - cnt;
        !            57:   inex = mpfr_check_range(x, rnd_mode);
        !            58:   if (inex)
        !            59:     return inex; /* underflow or overflow */
        !            60:
        !            61:   /* round if MPFR_PREC(x) smaller than length of i */
        !            62:   if (MPFR_PREC(x) < nbits)
        !            63:     {
        !            64:       int carry;
        !            65:
        !            66:       carry = mpfr_round_raw(xp+xn, xp+xn, nbits, (i < 0), MPFR_PREC(x),
        !            67:                              rnd_mode, &inex);
        !            68:       if (carry)
        !            69:         {
        !            70:           mp_exp_t exp = MPFR_EXP(x);
        !            71:
        !            72:           if (exp == __mpfr_emax)
        !            73:             return mpfr_set_overflow(x, rnd_mode, (i < 0 ? -1 : 1));
        !            74:
        !            75:           MPFR_EXP(x)++;
        !            76:           xp[xn] = GMP_LIMB_HIGHBIT;
        !            77:         }
        !            78:     }
1.1       maekawa    79:
1.1.1.2 ! ohara      80:   MPFR_RET(inex);
1.1       maekawa    81: }