Annotation of OpenXM_contrib/gmp/mpz/sqrt.c, Revision 1.1.1.2
1.1 maekawa 1: /* mpz_sqrt(root, u) -- Set ROOT to floor(sqrt(U)).
2:
1.1.1.2 ! maekawa 3: Copyright (C) 1991, 1993, 1994, 1996, 2000 Free Software Foundation, Inc.
1.1 maekawa 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
1.1.1.2 ! maekawa 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
1.1 maekawa 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
1.1.1.2 ! maekawa 14: or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
1.1 maekawa 15: License for more details.
16:
1.1.1.2 ! maekawa 17: You should have received a copy of the GNU Lesser General Public License
1.1 maekawa 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:
1.1.1.2 ! maekawa 22: #include <stdio.h> /* for NULL */
1.1 maekawa 23: #include "gmp.h"
24: #include "gmp-impl.h"
25:
26: void
27: #if __STDC__
28: mpz_sqrt (mpz_ptr root, mpz_srcptr op)
29: #else
30: mpz_sqrt (root, op)
31: mpz_ptr root;
32: mpz_srcptr op;
33: #endif
34: {
35: mp_size_t op_size, root_size;
36: mp_ptr root_ptr, op_ptr;
37: mp_ptr free_me = NULL;
38: mp_size_t free_me_size;
39: TMP_DECL (marker);
40:
41: TMP_MARK (marker);
42: op_size = op->_mp_size;
43: if (op_size < 0)
1.1.1.2 ! maekawa 44: SQRT_OF_NEGATIVE;
1.1 maekawa 45:
46: /* The size of the root is accurate after this simple calculation. */
47: root_size = (op_size + 1) / 2;
48:
49: root_ptr = root->_mp_d;
50: op_ptr = op->_mp_d;
51:
52: if (root->_mp_alloc < root_size)
53: {
54: if (root_ptr == op_ptr)
55: {
56: free_me = root_ptr;
57: free_me_size = root->_mp_alloc;
58: }
59: else
60: (*_mp_free_func) (root_ptr, root->_mp_alloc * BYTES_PER_MP_LIMB);
61:
62: root->_mp_alloc = root_size;
63: root_ptr = (mp_ptr) (*_mp_allocate_func) (root_size * BYTES_PER_MP_LIMB);
64: root->_mp_d = root_ptr;
65: }
66: else
67: {
68: /* Make OP not overlap with ROOT. */
69: if (root_ptr == op_ptr)
70: {
71: /* ROOT and OP are identical. Allocate temporary space for OP. */
72: op_ptr = (mp_ptr) TMP_ALLOC (op_size * BYTES_PER_MP_LIMB);
73: /* Copy to the temporary space. Hack: Avoid temporary variable
74: by using ROOT_PTR. */
75: MPN_COPY (op_ptr, root_ptr, op_size);
76: }
77: }
78:
79: mpn_sqrtrem (root_ptr, NULL, op_ptr, op_size);
80:
81: root->_mp_size = root_size;
82:
83: if (free_me != NULL)
84: (*_mp_free_func) (free_me, free_me_size * BYTES_PER_MP_LIMB);
85: TMP_FREE (marker);
86: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>