/* mpihelp-sub.c  -  MPI helper functions
   *	Copyright (C) 1994, 1996 Free Software Foundation, Inc.
   *	Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   *
   * This file is part of GnuPG.
   *
   * GnuPG is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * GnuPG is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
   *
   * Note: This code is heavily based on the GNU MP Library.
   *	 Actually it's the same code with only minor changes in the
   *	 way the data is stored; this is to support the abstraction
   *	 of an optional secure memory allocation which may be used
   *	 to avoid revealing of sensitive data due to paging etc.
   *	 The GNU MP Library itself is published under the LGPL;
   *	 however I decided to publish this code under the plain GPL.
   */
  
  #include "mpi-internal.h"
  
  /****************
   * Compare OP1_PTR/OP1_SIZE with OP2_PTR/OP2_SIZE.
   * There are no restrictions on the relative sizes of
   * the two arguments.
   * Return 1 if OP1 > OP2, 0 if they are equal, and -1 if OP1 < OP2.
   */
  int mpihelp_cmp(mpi_ptr_t op1_ptr, mpi_ptr_t op2_ptr, mpi_size_t size)
  {
  	mpi_size_t i;
  	mpi_limb_t op1_word, op2_word;
  
  	for (i = size - 1; i >= 0; i--) {
  		op1_word = op1_ptr[i];
  		op2_word = op2_ptr[i];
  		if (op1_word != op2_word)
  			goto diff;
  	}
  	return 0;
  
  diff:
  	/* This can *not* be simplified to
  	 *   op2_word - op2_word
  	 * since that expression might give signed overflow.  */
  	return (op1_word > op2_word) ? 1 : -1;
  }