private static int doVisitForPostorder(
Instruction curr, int currN, int[] postorder, boolean[] visited) {
visited[curr.num()] = true;
for (Instruction succ : curr.allSuccessors()) {
if (!visited[succ.num()]) {
currN = doVisitForPostorder(succ, currN, postorder, visited);
}
}
postorder[curr.num()] = --currN;
return currN;
}
private static void findReadsBeforeWrites(
Instruction[] flow,
TIntHashSet[] definitelyAssigned,
List<ReadWriteVariableInstruction> result,
TObjectIntHashMap<String> namesIndex,
int[] postorder,
int[] invpostorder,
boolean onlyFirstRead) {
// skip instructions that are not reachable from the start
int start = ArrayUtil.find(invpostorder, 0);
for (int i = start; i < flow.length; i++) {
int j = invpostorder[i];
Instruction curr = flow[j];
if (curr instanceof ReadWriteVariableInstruction) {
ReadWriteVariableInstruction rw = (ReadWriteVariableInstruction) curr;
int name = namesIndex.get(rw.getVariableName());
TIntHashSet vars = definitelyAssigned[j];
if (rw.isWrite()) {
if (vars == null) {
vars = new TIntHashSet();
definitelyAssigned[j] = vars;
}
vars.add(name);
} else {
if (vars == null || !vars.contains(name)) {
result.add(rw);
if (onlyFirstRead) {
if (vars == null) {
vars = new TIntHashSet();
definitelyAssigned[j] = vars;
}
vars.add(name);
}
}
}
}
for (Instruction succ : curr.allSuccessors()) {
if (postorder[succ.num()] > postorder[curr.num()]) {
TIntHashSet currDefinitelyAssigned = definitelyAssigned[curr.num()];
TIntHashSet succDefinitelyAssigned = definitelyAssigned[succ.num()];
if (currDefinitelyAssigned != null) {
int[] currArray = currDefinitelyAssigned.toArray();
if (succDefinitelyAssigned == null) {
succDefinitelyAssigned = new TIntHashSet();
succDefinitelyAssigned.addAll(currArray);
definitelyAssigned[succ.num()] = succDefinitelyAssigned;
} else {
succDefinitelyAssigned.retainAll(currArray);
}
} else {
if (succDefinitelyAssigned != null) {
succDefinitelyAssigned.clear();
} else {
succDefinitelyAssigned = new TIntHashSet();
definitelyAssigned[succ.num()] = succDefinitelyAssigned;
}
}
}
}
}
}