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Annotation of OpenXM_contrib/gmp/mpz/dive_ui.c, Revision 1.1

1.1     ! ohara       1: /* mpz_divexact_ui -- exact division mpz by ulong.
        !             2:
        !             3: Copyright 2001, 2002 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 Lesser General Public License as published by
        !             9: the Free Software Foundation; either version 2.1 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 Lesser General Public
        !            15: License for more details.
        !            16:
        !            17: You should have received a copy of the GNU Lesser 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:
        !            23: #include "gmp.h"
        !            24: #include "gmp-impl.h"
        !            25:
        !            26: void
        !            27: mpz_divexact_ui (mpz_ptr dst, mpz_srcptr src, unsigned long divisor)
        !            28: {
        !            29:   mp_size_t  size, abs_size;
        !            30:   mp_ptr     dst_ptr;
        !            31:
        !            32:   if (divisor == 0)
        !            33:     DIVIDE_BY_ZERO;
        !            34:
        !            35:   /* For nails don't try to be clever if d is bigger than a limb, just fake
        !            36:      up an mpz_t and go to the main mpz_divexact.  */
        !            37:   if (divisor > GMP_NUMB_MAX)
        !            38:     {
        !            39:       mp_limb_t  dlimbs[2];
        !            40:       mpz_t      dz;
        !            41:       ALLOC(dz) = 2;
        !            42:       PTR(dz) = dlimbs;
        !            43:       mpz_set_ui (dz, divisor);
        !            44:       mpz_divexact (dst, src, dz);
        !            45:       return;
        !            46:     }
        !            47:
        !            48:   size = SIZ(src);
        !            49:   if (size == 0)
        !            50:     {
        !            51:       SIZ(dst) = 0;
        !            52:       return;
        !            53:     }
        !            54:   abs_size = ABS (size);
        !            55:
        !            56:   MPZ_REALLOC (dst, abs_size);
        !            57:   dst_ptr = PTR(dst);
        !            58:
        !            59:   MPN_DIVREM_OR_DIVEXACT_1 (dst_ptr, PTR(src), abs_size, (mp_limb_t) divisor);
        !            60:   abs_size -= (dst_ptr[abs_size-1] == 0);
        !            61:   SIZ(dst) = (size >= 0 ? abs_size : -abs_size);
        !            62: }