void restrictTo8Bits(Register r){
  PhysicalRegisterSet phys=(PhysicalRegisterSet)this.phys;
  Register ESP=phys.getESP();
  Register EBP=phys.getEBP();
  Register ESI=phys.getESI();
  Register EDI=phys.getEDI();
  addRestriction(r,ESP);
  addRestriction(r,EBP);
  addRestriction(r,ESI);
  addRestriction(r,EDI);
}

void restrictTo8Bits ( Register r ) { PhysicalRegisterSet phys = ( PhysicalRegisterSet ) this . phys ; Register ESP = phys . getESP ( ) ; Register EBP = phys . getEBP ( ) ; Register ESI = phys . getESI ( ) ; Register EDI = phys . getEDI ( ) ; addRestriction ( r , ESP ) ; addRestriction ( r , EBP ) ; addRestriction ( r , ESI ) ; addRestriction ( r , EDI ) ; }
ensures that a particular register is only assigned to al , bl , cl , or dl , since these are the only 8 - bit registers we normally address .
