if (VM.VerifyAssertions) VM.assert(container.getAssignment().isAllocated());
if (VM.VerifyAssertions) VM._assert(container.getAssignment().isAllocated());
    void freeInterval(MappedBasicInterval bi) {      CompoundInterval container = bi.container;      OPT_Register r = container.getRegister();       if (r.isPhysical()) {        r.deallocateRegister();        return;      }      if (container.isSpilled()) {        // free the spill location iff this is the last interval in the        // compound interval.        BasicInterval last = (BasicInterval)container.last();        if (last.sameRange(bi)) {          spillManager.freeInterval(container.getSpillInterval());        }      } else {        // free the assigned register        if (VM.VerifyAssertions) VM.assert(container.getAssignment().isAllocated());        container.getAssignment().deallocateRegister();      }    }