public void attachLivenessInfo(FlowGraph flowGraph, FlowGraphDecorator flowGraphDecorator) {
for (Function function : flowGraph.getFunctions()) {
// Perform liveness analysis
TransferFunction<LiveVariableState> transferFunction = new LiveVariableTransferFunction();
BackwardAnalysis<LiveVariableState> analysis =
new BackwardAnalysis<LiveVariableState>(flowGraphDecorator, function);
Map<Node, LiveVariableState> states = analysis.solve(transferFunction);
// Attach live variables to each basic block
for (BasicBlock basicBlock : function.getBlocks()) {
LiveVariableState state =
transferFunction.join(flowGraphDecorator, states, basicBlock.getLastNode());
Set<Integer> liveVariables = state.getLiveVariables();
// NOTE: The EdgeTransfer function may use the conditional variable contained in an if node.
// We check if the last node of the basic block is an if node, and if it is, we add
// the conditional variable to the set of live variables.
if (basicBlock.getLastNode() instanceof IfNode) {
IfNode ifNode = (IfNode) basicBlock.getLastNode();
liveVariables.add(ifNode.getConditionVar());
}
int[] result = new int[liveVariables.size()];
Iterator<Integer> iterator = liveVariables.iterator();
int i = 0;
while (iterator.hasNext()) {
result[i] = iterator.next();
i++;
}
basicBlock.setLiveVariables(result);
}
}
}
