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Annotation of OpenXM_contrib/gmp/mpz/tdiv_q.c, Revision 1.1.1.3

1.1       maekawa     1: /* mpz_tdiv_q -- divide two integers and produce a quotient.
                      2:
1.1.1.3 ! ohara       3: Copyright 1991, 1993, 1994, 1996, 2000, 2001 Free Software Foundation, Inc.
1.1       maekawa     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
1.1.1.2   maekawa     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 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
1.1.1.2   maekawa    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   maekawa    17: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    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: mpz_tdiv_q (mpz_ptr quot, mpz_srcptr num, mpz_srcptr den)
                     28: {
1.1.1.2   maekawa    29:   mp_size_t ql;
                     30:   mp_size_t ns, ds, nl, dl;
                     31:   mp_ptr np, dp, qp, rp;
1.1       maekawa    32:   TMP_DECL (marker);
                     33:
1.1.1.2   maekawa    34:   ns = SIZ (num);
                     35:   ds = SIZ (den);
                     36:   nl = ABS (ns);
                     37:   dl = ABS (ds);
                     38:   ql = nl - dl + 1;
1.1       maekawa    39:
1.1.1.2   maekawa    40:   if (dl == 0)
                     41:     DIVIDE_BY_ZERO;
1.1       maekawa    42:
1.1.1.2   maekawa    43:   if (ql <= 0)
1.1       maekawa    44:     {
1.1.1.2   maekawa    45:       SIZ (quot) = 0;
1.1       maekawa    46:       return;
                     47:     }
                     48:
1.1.1.2   maekawa    49:   MPZ_REALLOC (quot, ql);
1.1       maekawa    50:
                     51:   TMP_MARK (marker);
1.1.1.2   maekawa    52:   qp = PTR (quot);
                     53:   rp = (mp_ptr) TMP_ALLOC (dl * BYTES_PER_MP_LIMB);
                     54:   np = PTR (num);
                     55:   dp = PTR (den);
                     56:
                     57:   /* FIXME: We should think about how to handle the temporary allocation.
                     58:      Perhaps mpn_tdiv_qr should handle it, since it anyway often needs to
                     59:      allocate temp space.  */
1.1       maekawa    60:
1.1.1.2   maekawa    61:   /* Copy denominator to temporary space if it overlaps with the quotient.  */
                     62:   if (dp == qp)
1.1       maekawa    63:     {
                     64:       mp_ptr tp;
1.1.1.2   maekawa    65:       tp = (mp_ptr) TMP_ALLOC (dl * BYTES_PER_MP_LIMB);
                     66:       MPN_COPY (tp, dp, dl);
1.1       maekawa    67:       dp = tp;
                     68:     }
1.1.1.2   maekawa    69:   /* Copy numerator to temporary space if it overlaps with the quotient.  */
                     70:   if (np == qp)
1.1       maekawa    71:     {
1.1.1.2   maekawa    72:       mp_ptr tp;
                     73:       tp = (mp_ptr) TMP_ALLOC (nl * BYTES_PER_MP_LIMB);
                     74:       MPN_COPY (tp, np, nl);
                     75:       np = tp;
1.1       maekawa    76:     }
                     77:
1.1.1.2   maekawa    78:   mpn_tdiv_qr (qp, rp, 0L, np, nl, dp, dl);
1.1       maekawa    79:
1.1.1.2   maekawa    80:   ql -=  qp[ql - 1] == 0;
1.1       maekawa    81:
1.1.1.2   maekawa    82:   SIZ (quot) = (ns ^ ds) >= 0 ? ql : -ql;
1.1       maekawa    83:   TMP_FREE (marker);
                     84: }