#ifndef LOOPUNROLL_HPP
#define LOOPUNROLL_HPP
#include "BasicBlock.h"
#include "Module.h"
#include "PassManager.hpp"

#include <ostream>
#include <string>
#include <vector>

using std::cout;
using std::endl;
using std::string;
using std::to_string;
using std::vector;

namespace Graph {

using Edge = std::pair<BasicBlock *, BasicBlock *>;
using BackEdgeList = vector<Edge>;
using SimpleLoop = vector<BasicBlock *>;
}


/*  This is a class to unroll simple loops:
 *  - strict structure:
 *     --a->b->c---
 *       ^-----+
 *  - if the loop has constant times, unroll it.
 */
class LoopUnroll : public Pass {
  public:
    LoopUnroll(Module *_m) : Pass(_m) {
        for (auto &f : m_->get_functions())
            if (f.get_name() == "neg_idx_except") {
                neg_func = &f;
                break;
            }
        if (neg_func == nullptr)
            assert(false && "find function neg_idx_except first!");
    }

    LoopUnroll() = delete;

    void run() override;
    static string str(const Graph::Edge &edge) {
        return "(" + edge.first->get_name() + ", " + edge.second->get_name() +
               ")";
    }

  private:
    Function *neg_func;
    Graph::BackEdgeList detect_back(Function *);
    vector<Graph::SimpleLoop> check_sloops(const Graph::BackEdgeList &) const;
};
#endif