Return to div_ui.c CVS log

Up to [local] / OpenXM_contrib / gmp / mpf

Annotation of OpenXM_contrib/gmp/mpf/div_ui.c, Revision 1.1.1.1

1.1       maekawa     1: /* mpf_div_ui -- Divide a float with an unsigned integer.
                      2:
                      3: Copyright (C) 1993, 1994, 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: #include "longlong.h"
                     25:
                     26: void
                     27: #if __STDC__
                     28: mpf_div_ui (mpf_ptr r, mpf_srcptr u, unsigned long int v)
                     29: #else
                     30: mpf_div_ui (r, u, v)
                     31:      mpf_ptr r;
                     32:      mpf_srcptr u;
                     33:      unsigned long int v;
                     34: #endif
                     35: {
                     36:   mp_srcptr up;
                     37:   mp_ptr rp, tp, rtp;
                     38:   mp_size_t usize;
                     39:   mp_size_t rsize, tsize;
                     40:   mp_size_t sign_quotient;
                     41:   mp_size_t prec;
                     42:   mp_limb_t q_limb;
                     43:   mp_exp_t rexp;
                     44:   TMP_DECL (marker);
                     45:
                     46:   usize = u->_mp_size;
                     47:   sign_quotient = usize;
                     48:   usize = ABS (usize);
                     49:   prec = r->_mp_prec;
                     50:
                     51:   if (v == 0)
                     52:     v = 1 / v;                 /* divide by zero as directed */
                     53:   if (usize == 0)
                     54:     {
                     55:       r->_mp_size = 0;
                     56:       r->_mp_exp = 0;
                     57:       return;
                     58:     }
                     59:
                     60:   TMP_MARK (marker);
                     61:
                     62:   rp = r->_mp_d;
                     63:   up = u->_mp_d;
                     64:
                     65:   tsize = 1 + prec;
                     66:   tp = (mp_ptr) TMP_ALLOC ((tsize + 1) * BYTES_PER_MP_LIMB);
                     67:
                     68:   if (usize > tsize)
                     69:     {
                     70:       up += usize - tsize;
                     71:       usize = tsize;
                     72:       rtp = tp;
                     73:     }
                     74:   else
                     75:     {
                     76:       MPN_ZERO (tp, tsize - usize);
                     77:       rtp = tp + (tsize - usize);
                     78:     }
                     79:
                     80:   /* Move the dividend to the remainder.  */
                     81:   MPN_COPY (rtp, up, usize);
                     82:
                     83:   mpn_divmod_1 (rp, tp, tsize, (mp_limb_t) v);
                     84:   q_limb = rp[tsize - 1];
                     85:
                     86:   rsize = tsize - (q_limb == 0);
                     87:   rexp = u->_mp_exp - (q_limb == 0);
                     88:   r->_mp_size = sign_quotient >= 0 ? rsize : -rsize;
                     89:   r->_mp_exp = rexp;
                     90:   TMP_FREE (marker);
                     91: }