# include "y3.h" 

void precftn( r, t, s )
{
  /* decide a shift/reduce conflict by precedence.*/
  /* r is a rule number, t a token number */
  /* the conflict is in state s */
  /* temp1[t] is changed to reflect the action */

  int lp,
      lt,
      action;

  lp = levprd[ r ];
  lt = toklev[ t ];
  if ( PLEVEL( lt ) == 0 || PLEVEL( lp ) == 0 )
    {
      /* conflict */
      if ( foutput != NULL )
        fprintf( foutput,
                 "\n%d: shift/reduce conflict (shift %d, red'n %d) on %s",
                 s,
                 temp1[ t ],
                 r,
                 symnam( t ) );
      ++zzsrconf;
      return;
    }
  if ( PLEVEL( lt ) == PLEVEL( lp ) )
    action = ASSOC( lt );
  else
    if ( PLEVEL( lt ) > PLEVEL( lp ) )
      action = RASC; /* shift */
    else
      action = LASC; /* reduce */

  switch ( action )
    {

      case BASC : /* error action */
        temp1[ t ] = ERRCODE;
        return;

      case LASC : /* reduce */
        temp1[ t ] = -r;
        return;

    }
}