package ch.usi.inf.sp.dom;

import ch.usi.inf.sp.cfg.BasicBlock;
import ch.usi.inf.sp.cfg.ControlFlowGraph;
import ch.usi.inf.sp.graph.Traversal;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


public class DominatorAnalyzer {

    /**
     * Cooper et al.'s "Engineered Algorithm".
     * ================================================================
     * for all nodes, b   // initialize the dominators array
     *     doms[b] ← Undefined
     * doms[entryNode] ← entryNode
     * Changed ← true
     * while (Changed)
     *     Changed ← false
     *     for all nodes, b, in reverse postorder (except entryNode)
     *         newidom ← first (processed) predecessor of b    // (pick one)
     *         for all other predecessors, p, of b
     *             if doms[p] != Undefined   // i.e., if doms[p] already calculated
     *                 newidom ← intersect(p, newidom)
     *         if doms[b] != newidom
     *             doms[b] ← newidom
     *             Changed ← true
     *
     * function intersect(b1, b2) returns node
     *     finger1 ← b1
     *     finger2 ← b2
     *     while (finger1 != finger2)
     *         while (finger1 < finger2)
     *             finger1 = doms[finger1]
     *         while (finger2 < finger1)
     *             finger2 = doms[finger2]
     *     return finger1
     * ================================================================
     * Figure 3 of Cooper, Harvey, Kennedy
     */
    public static DominatorTree analyze(final ControlFlowGraph cfg) {
        //TODO
        return null;
    }

    // probably add a method intersect(...)

}