private static void placePhi(MethodNode mth, int regNum, LiveVarAnalysis la) {
List<BlockNode> blocks = mth.getBasicBlocks();
int blocksCount = blocks.size();
BitSet hasPhi = new BitSet(blocksCount);
BitSet processed = new BitSet(blocksCount);
Deque<BlockNode> workList = new LinkedList<BlockNode>();
BitSet assignBlocks = la.getAssignBlocks(regNum);
for (int id = assignBlocks.nextSetBit(0); id >= 0; id = assignBlocks.nextSetBit(id + 1)) {
processed.set(id);
workList.add(blocks.get(id));
}
while (!workList.isEmpty()) {
BlockNode block = workList.pop();
BitSet domFrontier = block.getDomFrontier();
for (int id = domFrontier.nextSetBit(0); id >= 0; id = domFrontier.nextSetBit(id + 1)) {
if (!hasPhi.get(id) && la.isLive(id, regNum)) {
BlockNode df = blocks.get(id);
addPhi(df, regNum);
hasPhi.set(id);
if (!processed.get(id)) {
processed.set(id);
workList.add(df);
}
}
}
}
}
private static void process(MethodNode mth) {
LiveVarAnalysis la = new LiveVarAnalysis(mth);
la.runAnalysis();
int regsCount = mth.getRegsCount();
for (int i = 0; i < regsCount; i++) {
placePhi(mth, i, la);
}
renameVariables(mth);
fixLastTryCatchAssign(mth);
if (removeUselessPhi(mth)) {
renameVariables(mth);
}
}