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Annotation of OpenXM_contrib/gmp/mpfr/ui_div.c, Revision 1.1.1.1

1.1       ohara       1: /* mpfr_ui_div -- divide a machine integer by a floating-point number
                      2:
                      3: Copyright 2000, 2001 Free Software Foundation, Inc.
                      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 <stdio.h>
                     23: #include "gmp.h"
                     24: #include "gmp-impl.h"
                     25: #include "longlong.h"
                     26: #include "mpfr.h"
                     27: #include "mpfr-impl.h"
                     28:
                     29: int
                     30: mpfr_ui_div (mpfr_ptr y, unsigned long int u, mpfr_srcptr x, mp_rnd_t rnd_mode)
                     31: {
                     32:   mpfr_t uu;
                     33:   mp_limb_t up[1];
                     34:   unsigned long cnt;
                     35:
                     36:   if (MPFR_IS_NAN(x))
                     37:     {
                     38:       MPFR_SET_NAN(y);
                     39:       MPFR_RET_NAN;
                     40:     }
                     41:
                     42:   MPFR_CLEAR_NAN(y);
                     43:
                     44:   if (MPFR_IS_INF(x)) /* u/Inf = 0 */
                     45:     {
                     46:       MPFR_CLEAR_INF(y);
                     47:       MPFR_SET_ZERO(y);
                     48:       if (MPFR_SIGN(x) != MPFR_SIGN(y))
                     49:        MPFR_CHANGE_SIGN(y);
                     50:       MPFR_RET(0);
                     51:     }
                     52:
                     53:   MPFR_CLEAR_INF(y);
                     54:
                     55:   if (u)
                     56:     {
                     57:       MPFR_INIT1(up, uu, BITS_PER_MP_LIMB, 1);
                     58:       count_leading_zeros(cnt, (mp_limb_t) u);
                     59:       *up = (mp_limb_t) u << cnt;
                     60:       MPFR_EXP(uu) = BITS_PER_MP_LIMB-cnt;
                     61:
                     62:       return mpfr_div (y, uu, x, rnd_mode);
                     63:     }
                     64:   else /* u = 0 */
                     65:     {
                     66:       if (MPFR_IS_ZERO(x)) /* 0/0 */
                     67:        {
                     68:          MPFR_SET_NAN(y);
                     69:          MPFR_RET_NAN;
                     70:        }
                     71:       else
                     72:        {
                     73:          MPFR_SET_ZERO(y); /* if u=0, then set y to 0 */
                     74:          MPFR_RET(0);
                     75:        }
                     76:     }
                     77: }