private void search(BasicBlock X) {
for(Statement stmt : X.getStatements()) {
Expression rhs = stmt.getRHS();
if(!(rhs instanceof PhiFunction)) {
for(Variable V : rhs.variables()) {
int i = Top(V);
rhs = rhs.replaceVariable(V, new SsaVariable(V, i));
}
stmt = X.replaceStatement(stmt, stmt.withRHS(rhs));
}