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

1.1     ! maekawa     1: /* mpz_sqrtrem(root,rem,x) -- Set ROOT to floor(sqrt(X)) and REM
        !             2:    to the remainder, i.e. X - ROOT**2.
        !             3:
        !             4: Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.
        !             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
        !             9: it under the terms of the GNU Library General Public License as published by
        !            10: the Free Software Foundation; either version 2 of the License, or (at your
        !            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
        !            15: or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Library General Public
        !            16: License for more details.
        !            17:
        !            18: You should have received a copy of the GNU Library General Public License
        !            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 "gmp.h"
        !            24: #include "gmp-impl.h"
        !            25:
        !            26: #ifndef BERKELEY_MP
        !            27: void
        !            28: #if __STDC__
        !            29: mpz_sqrtrem (mpz_ptr root, mpz_ptr rem, mpz_srcptr op)
        !            30: #else
        !            31: mpz_sqrtrem (root, rem, op)
        !            32:      mpz_ptr root;
        !            33:      mpz_ptr rem;
        !            34:      mpz_srcptr op;
        !            35: #endif
        !            36: #else /* BERKELEY_MP */
        !            37: void
        !            38: #if __STDC__
        !            39: msqrt (mpz_srcptr op, mpz_ptr root, mpz_ptr rem)
        !            40: #else
        !            41: msqrt (op, root, rem)
        !            42:      mpz_srcptr op;
        !            43:      mpz_ptr root;
        !            44:      mpz_ptr rem;
        !            45: #endif
        !            46: #endif /* BERKELEY_MP */
        !            47: {
        !            48:   mp_size_t op_size, root_size, rem_size;
        !            49:   mp_ptr root_ptr, op_ptr;
        !            50:   mp_ptr free_me = NULL;
        !            51:   mp_size_t free_me_size;
        !            52:   TMP_DECL (marker);
        !            53:
        !            54:   TMP_MARK (marker);
        !            55:   op_size = op->_mp_size;
        !            56:   if (op_size < 0)
        !            57:     op_size = 1 / (op_size > 0); /* Divide by zero for negative OP.  */
        !            58:
        !            59:   if (rem->_mp_alloc < op_size)
        !            60:     _mpz_realloc (rem, op_size);
        !            61:
        !            62:   /* The size of the root is accurate after this simple calculation.  */
        !            63:   root_size = (op_size + 1) / 2;
        !            64:
        !            65:   root_ptr = root->_mp_d;
        !            66:   op_ptr = op->_mp_d;
        !            67:
        !            68:   if (root->_mp_alloc < root_size)
        !            69:     {
        !            70:       if (root_ptr == op_ptr)
        !            71:        {
        !            72:          free_me = root_ptr;
        !            73:          free_me_size = root->_mp_alloc;
        !            74:        }
        !            75:       else
        !            76:        (*_mp_free_func) (root_ptr, root->_mp_alloc * BYTES_PER_MP_LIMB);
        !            77:
        !            78:       root->_mp_alloc = root_size;
        !            79:       root_ptr = (mp_ptr) (*_mp_allocate_func) (root_size * BYTES_PER_MP_LIMB);
        !            80:       root->_mp_d = root_ptr;
        !            81:     }
        !            82:   else
        !            83:     {
        !            84:       /* Make OP not overlap with ROOT.  */
        !            85:       if (root_ptr == op_ptr)
        !            86:        {
        !            87:          /* ROOT and OP are identical.  Allocate temporary space for OP.  */
        !            88:          op_ptr = (mp_ptr) TMP_ALLOC (op_size * BYTES_PER_MP_LIMB);
        !            89:          /* Copy to the temporary space.  Hack: Avoid temporary variable
        !            90:             by using ROOT_PTR.  */
        !            91:          MPN_COPY (op_ptr, root_ptr, op_size);
        !            92:        }
        !            93:     }
        !            94:
        !            95:   rem_size = mpn_sqrtrem (root_ptr, rem->_mp_d, op_ptr, op_size);
        !            96:
        !            97:   root->_mp_size = root_size;
        !            98:
        !            99:   /* Write remainder size last, to enable us to define this function to
        !           100:      give only the square root remainder, if the user calls if with
        !           101:      ROOT == REM.  */
        !           102:   rem->_mp_size = rem_size;
        !           103:
        !           104:   if (free_me != NULL)
        !           105:     (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
        !           106:   TMP_FREE (marker);
        !           107: }