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Annotation of OpenXM_contrib/gmp/mpz/tdiv_qr_ui.c, Revision 1.1.1.1

1.1       maekawa     1: /* mpz_tdiv_qr_ui(quot,rem,dividend,short_divisor) --
                      2:    Set QUOT to DIVIDEND / SHORT_DIVISOR
                      3:    and REM to DIVIDEND mod SHORT_DIVISOR.
                      4:
                      5: Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.
                      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
                     10: it under the terms of the GNU Library General Public License as published by
                     11: the Free Software Foundation; either version 2 of the License, or (at your
                     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
                     16: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
                     17: License for more details.
                     18:
                     19: You should have received a copy of the GNU Library General Public License
                     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:
                     27: void
                     28: #if __STDC__
                     29: mpz_tdiv_qr_ui (mpz_ptr quot, mpz_ptr rem, mpz_srcptr dividend, unsigned long int divisor)
                     30: #else
                     31: mpz_tdiv_qr_ui (quot, rem, dividend, divisor)
                     32:      mpz_ptr quot;
                     33:      mpz_ptr rem;
                     34:      mpz_srcptr dividend;
                     35:      unsigned long int divisor;
                     36: #endif
                     37: {
                     38:   mp_size_t dividend_size;
                     39:   mp_size_t size;
                     40:   mp_ptr quot_ptr;
                     41:   mp_limb_t remainder_limb;
                     42:
                     43:   dividend_size = dividend->_mp_size;
                     44:   size = ABS (dividend_size);
                     45:
                     46:   if (size == 0)
                     47:     {
                     48:       quot->_mp_size = 0;
                     49:       rem->_mp_size = 0;
                     50:       return;
                     51:     }
                     52:
                     53:   /* No need for temporary allocation and copying if QUOT == DIVIDEND as
                     54:      the divisor is just one limb, and thus no intermediate remainders
                     55:      need to be stored.  */
                     56:
                     57:   if (quot->_mp_alloc < size)
                     58:     _mpz_realloc (quot, size);
                     59:
                     60:   quot_ptr = quot->_mp_d;
                     61:
                     62:   remainder_limb = mpn_divmod_1 (quot_ptr, dividend->_mp_d, size,
                     63:                                   (mp_limb_t) divisor);
                     64:
                     65:   if (remainder_limb == 0)
                     66:     rem->_mp_size = 0;
                     67:   else
                     68:     {
                     69:       /* Store the single-limb remainder.  We don't check if there's space
                     70:         for just one limb, since no function ever makes zero space.  */
                     71:       rem->_mp_size = dividend_size >= 0 ? 1 : -1;
                     72:       rem->_mp_d[0] = remainder_limb;
                     73:     }
                     74:
                     75:   /* The quotient is SIZE limbs, but the most significant might be zero. */
                     76:   size -= quot_ptr[size - 1] == 0;
                     77:   quot->_mp_size = dividend_size >= 0 ? size : -size;
                     78: }