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[glibc/history.git] / stdlib / cmp.c
blobe7661702b60cb559474f8e46c7a7329a53e20e50
1 /* mpn_cmp -- Compare two low-level natural-number integers.
3 Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc.
5 This file is part of the GNU MP Library.
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.
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.
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. */
22 #include <gmp.h>
23 #include "gmp-impl.h"
25 /* Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
26 There are no restrictions on the relative sizes of
27 the two arguments.
28 Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2. */
30 int
31 #if __STDC__
32 mpn_cmp (mp_srcptr op1_ptr, mp_srcptr op2_ptr, mp_size_t size)
33 #else
34 mpn_cmp (op1_ptr, op2_ptr, size)
35 mp_srcptr op1_ptr;
36 mp_srcptr op2_ptr;
37 mp_size_t size;
38 #endif
40 mp_size_t i;
41 mp_limb_t op1_word, op2_word;
43 for (i = size - 1; i >= 0; i--)
45 op1_word = op1_ptr[i];
46 op2_word = op2_ptr[i];
47 if (op1_word != op2_word)
48 goto diff;
50 return 0;
51 diff:
52 /* This can *not* be simplified to
53 op2_word - op2_word
54 since that expression might give signed overflow. */
55 return (op1_word > op2_word) ? 1 : -1;