1 /* mpn_cmp -- Compare two low-level natural-number integers. 2 3 Copyright (C) 1991, 1993, 1994, 1996 Free Software Foundation, Inc. 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 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. 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 14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public 15 License for more details. 16 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. */ 21 22 #include "gmp.h" 23 #include "gmp-impl.h" 24 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. */ 29 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 39 { 40 mp_size_t i; 41 mp_limb_t op1_word, op2_word; 42 43 for (i = size - 1; i >= 0; i--) 44 { 45 op1_word = op1_ptr[i]; 46 op2_word = op2_ptr[i]; 47 if (op1_word != op2_word) 48 goto diff; 49 } 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; 56 } 57