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

1.1       maekawa     1: /* mpz_tdiv_r_ui(rem, dividend, divisor_limb)
                      2:    -- Set REM to DIVDEND mod DIVISOR_LIMB.
                      3:
1.1.1.3 ! ohara       4: Copyright 1991, 1993, 1994, 1996, 1998, 2001, 2002 Free Software Foundation,
        !             5: Inc.
1.1       maekawa     6:
                      7: This file is part of the GNU MP Library.
                      8:
                      9: The GNU MP Library is free software; you can redistribute it and/or modify
1.1.1.2   maekawa    10: it under the terms of the GNU Lesser General Public License as published by
                     11: the Free Software Foundation; either version 2.1 of the License, or (at your
1.1       maekawa    12: option) any later version.
                     13:
                     14: The GNU MP Library is distributed in the hope that it will be useful, but
                     15: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1.1.1.2   maekawa    16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    17: License for more details.
                     18:
1.1.1.2   maekawa    19: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    20: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     21: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     22: MA 02111-1307, USA. */
                     23:
                     24: #include "gmp.h"
                     25: #include "gmp-impl.h"
                     26:
1.1.1.2   maekawa    27: unsigned long int
1.1       maekawa    28: mpz_tdiv_r_ui (mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor)
                     29: {
1.1.1.3 ! ohara      30:   mp_size_t ns, nn;
        !            31:   mp_ptr np;
        !            32:   mp_limb_t rl;
1.1       maekawa    33:
1.1.1.2   maekawa    34:   if (divisor == 0)
                     35:     DIVIDE_BY_ZERO;
                     36:
1.1.1.3 ! ohara      37:   ns = SIZ(dividend);
        !            38:   if (ns == 0)
        !            39:     {
        !            40:       SIZ(rem) = 0;
        !            41:       return 0;
        !            42:     }
1.1       maekawa    43:
1.1.1.3 ! ohara      44:   nn = ABS(ns);
        !            45:   np = PTR(dividend);
        !            46: #if GMP_NAIL_BITS != 0
        !            47:   if (divisor > GMP_NUMB_MAX)
        !            48:     {
        !            49:       mp_limb_t dp[2];
        !            50:       mp_ptr rp, qp;
        !            51:       mp_size_t rn;
        !            52:       TMP_DECL (mark);
        !            53:
        !            54:       if (nn == 1)             /* tdiv_qr requirements; tested above for 0 */
        !            55:        {
        !            56:          rl = np[0];
        !            57:          SIZ(rem) = ns >= 0 ? 1 : -1;
        !            58:          PTR(rem)[0] = rl;
        !            59:          return rl;
        !            60:        }
        !            61:
        !            62:       MPZ_REALLOC (rem, 2);
        !            63:       rp = PTR(rem);
        !            64:
        !            65:       TMP_MARK (mark);
        !            66:       dp[0] = divisor & GMP_NUMB_MASK;
        !            67:       dp[1] = divisor >> GMP_NUMB_BITS;
        !            68:       qp = TMP_ALLOC_LIMBS (nn - 2 + 1);
        !            69:       mpn_tdiv_qr (qp, rp, (mp_size_t) 0, np, nn, dp, (mp_size_t) 2);
        !            70:       TMP_FREE (mark);
        !            71:       rl = rp[0] + (rp[1] << GMP_NUMB_BITS);
        !            72:       rn = 2 - (rp[1] == 0);  rn -= (rp[rn - 1] == 0);
        !            73:       SIZ(rem) = ns >= 0 ? rn : -rn;
        !            74:     }
1.1       maekawa    75:   else
1.1.1.3 ! ohara      76: #endif
1.1       maekawa    77:     {
1.1.1.3 ! ohara      78:       rl = mpn_mod_1 (np, nn, (mp_limb_t) divisor);
        !            79:       if (rl == 0)
        !            80:        SIZ(rem) = 0;
        !            81:       else
        !            82:        {
        !            83:          /* Store the single-limb remainder.  We don't check if there's space
        !            84:             for just one limb, since no function ever makes zero space.  */
        !            85:          SIZ(rem) = ns >= 0 ? 1 : -1;
        !            86:          PTR(rem)[0] = rl;
        !            87:        }
1.1       maekawa    88:     }
1.1.1.2   maekawa    89:
1.1.1.3 ! ohara      90:   return rl;
1.1       maekawa    91: }