question: private void addBlockToWorklist ( SsaBasicBlock ssaBlock ) { if ( ! executableBlocks . get ( ssaBlock . getIndex ( ) ) ) { cfgWorklist . add ( ssaBlock ) ; executableBlocks . set ( ssaBlock . getIndex ( ) ) ; } else { cfgPhiWorklist . add ( ssaBlock ) ; } }
target:  Adds a SSA basic block to the CFG worklist if it's unexecuted, or to the CFG phi worklist if it's already executed.