Annotation of OpenXM/src/kan96xx/gmp-2.0.2/mpz/sqrtrem.c, Revision 1.1.1.1
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: }
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