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Annotation of OpenXM_contrib/gmp/mpbsd/sdiv.c, Revision 1.1.1.3

1.1       maekawa     1: /* sdiv -- Divide a MINT by a short integer.  Produce a MINT quotient
                      2:    and a short remainder.
                      3:
1.1.1.3 ! ohara       4: Copyright 1991, 1994, 1995, 2000, 2001 Free Software Foundation, Inc.
1.1       maekawa     5:
                      6: This file is part of the GNU MP Library.
                      7:
                      8: The GNU MP Library is free software; you can redistribute it and/or modify
1.1.1.2   maekawa     9: it under the terms of the GNU Lesser General Public License as published by
                     10: the Free Software Foundation; either version 2.1 of the License, or (at your
1.1       maekawa    11: option) any later version.
                     12:
                     13: The GNU MP Library is distributed in the hope that it will be useful, but
                     14: WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
1.1.1.2   maekawa    15: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
1.1       maekawa    16: License for more details.
                     17:
1.1.1.2   maekawa    18: You should have received a copy of the GNU Lesser General Public License
1.1       maekawa    19: along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
                     20: the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
                     21: MA 02111-1307, USA. */
                     22:
                     23: #include "mp.h"
                     24: #include "gmp.h"
                     25: #include "gmp-impl.h"
                     26: #include "longlong.h"
                     27:
                     28: void
                     29: sdiv (const MINT *dividend, signed short int divisor_short, MINT *quot, short *rem_ptr)
                     30: {
                     31:   mp_size_t sign_dividend;
                     32:   signed long int sign_divisor;
                     33:   mp_size_t dividend_size, quot_size;
                     34:   mp_ptr dividend_ptr, quot_ptr;
                     35:   mp_limb_t divisor_limb;
                     36:   mp_limb_t remainder_limb;
                     37:
                     38:   sign_dividend = dividend->_mp_size;
                     39:   dividend_size = ABS (dividend->_mp_size);
                     40:
                     41:   if (dividend_size == 0)
                     42:     {
                     43:       quot->_mp_size = 0;
                     44:       *rem_ptr = 0;
                     45:       return;
                     46:     }
                     47:
                     48:   sign_divisor = divisor_short;
1.1.1.2   maekawa    49:   divisor_limb = (unsigned short) ABS (divisor_short);
1.1       maekawa    50:
                     51:   /* No need for temporary allocation and copying even if QUOT == DIVIDEND
                     52:      as the divisor is just one limb, and thus no intermediate remainders
                     53:      need to be stored.  */
                     54:
                     55:   if (quot->_mp_alloc < dividend_size)
                     56:     _mp_realloc (quot, dividend_size);
                     57:
                     58:   quot_ptr = quot->_mp_d;
                     59:   dividend_ptr = dividend->_mp_d;
                     60:
                     61:   remainder_limb = mpn_divmod_1 (quot_ptr,
                     62:                                 dividend_ptr, dividend_size, divisor_limb);
                     63:
                     64:   *rem_ptr = sign_dividend >= 0 ? remainder_limb : -remainder_limb;
                     65:   /* The quotient is DIVIDEND_SIZE limbs, but the most significant
                     66:      might be zero.  Set QUOT_SIZE properly. */
                     67:   quot_size = dividend_size - (quot_ptr[dividend_size - 1] == 0);
                     68:   quot->_mp_size = (sign_divisor ^ sign_dividend) >= 0 ? quot_size : -quot_size;
                     69: }