ACStone/124.loop.c at master · ArchC/ACStone · GitHub

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/**
 * @file      124.loop.c
 * @author    The ArchC Team
 *            http://www.archc.org/
 *
 *            Computer Systems Laboratory (LSC)
 *            IC-UNICAMP
 *            http://www.lsc.ic.unicamp.br
 *
 * @version   1.0
 * @date      Mon, 19 Jun 2006 15:33:21 -0300
 * @brief     It is a simple main function that uses a implemented signed multiplication (Booth)
 *
 * @attention Copyright (C) 2002-2006 --- The ArchC Team
 *
 * This program 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.
 *
 * This program 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

/* The file begin.h is included if compiler flag -DBEGINCODE is used */
#ifdef BEGINCODE
#include "begin.h"
#endif

int main() {

  unsigned char count;
  unsigned int A,Q,Qmenos,M,mask;
  signed long long int result;

  count=32; /* 32 bits * 32 bits = 64 bits */

  /* Some variable */
  M=0x82348243;
  Q=0x41378972;
  Qmenos=0x00000000;
  A=0x00000000;

  while(count!=0) {

    mask=(((Q<<1) & 0x00000002) | (Qmenos & 0x00000001));

    switch(mask) {

    case 0x0: /* q0=0 and qm=0 */
    case 0x3: /* qo=1 and qm=1 */
      /* Nothing */
      break;

    case 0x2: /* q0=1 and qm=0 */
      A=A-M;
      break;

    case 0x1: /* q0=0 and qm=1 */
      A=A+M;
      break;

    }

    /* Shift */
    if(Q & 0x00000001)
      Qmenos=1;
    else
      Qmenos=0;

    Q=Q>>1;

    if(A & 0x00000001)
      Q=(Q | 0x80000000);
    else
      Q=(Q & 0x7FFFFFFF);

    A=A>>1;
    if(A & 0x40000000)
      A=(A | 0x80000000);

    count--;
  }

  result=0;
  result=((((unsigned long long int)(A)) << 32) |
	  ((unsigned long long int)(Q)));
  /* Before result must be -2309208815826051882 */ result=0;

  return 0;
  /* Return 0 only */
}

/* The file end.h is included if compiler flag -DENDCODE is used */
#ifdef ENDCODE
#include "end.h"
#endif