1/* mpn_cmp -- Compare two low-level natural-number integers.
2
3Copyright (C) 1991-2020 Free Software Foundation, Inc.
4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 2.1 of the License, or (at your
10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
15License for more details.
16
17You should have received a copy of the GNU Lesser General Public License
18along with the GNU MP Library; see the file COPYING.LIB. If not, see
19<https://www.gnu.org/licenses/>. */
20
21#include <gmp.h>
22#include "gmp-impl.h"
23
24/* Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
25 There are no restrictions on the relative sizes of
26 the two arguments.
27 Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2. */
28
29int
30mpn_cmp (mp_srcptr op1_ptr, mp_srcptr op2_ptr, mp_size_t size)
31{
32 mp_size_t i;
33 mp_limb_t op1_word, op2_word;
34
35 for (i = size - 1; i >= 0; i--)
36 {
37 op1_word = op1_ptr[i];
38 op2_word = op2_ptr[i];
39 if (op1_word != op2_word)
40 goto diff;
41 }
42 return 0;
43 diff:
44 /* This can *not* be simplified to
45 op2_word - op2_word
46 since that expression might give signed overflow. */
47 return (op1_word > op2_word) ? 1 : -1;
48}
49