[blocks] Add dominance analysis over CFGs

include/blocks/dominance.h

@@ -0,0 +1,55 @@
+#ifndef DOMINANCE_H
+#define DOMINANCE_H
+#include "blocks/block_visitor.h"
+#include "blocks/basic_blocks.h"
+#include "blocks/stmt.h"
+#include <map>
+#include <vector>
+#include <stack>
+#include <string>
+#include <bitset>
+#include <algorithm>
+
+namespace block {
+class dominator_analysis {
+    public:
+        dominator_analysis(basic_block::cfg_block cfg, bool is_postdom = false);
+        basic_block::cfg_block cfg_;
+        bool is_postdom_;
+        int max_depth;
+        unsigned int max_depth_bb_id;
+        std::vector<int> &get_postorder_bb_map();
+        std::vector<int> &get_postorder();
+        std::vector<int> &get_preorder_bb_map();
+        std::vector<int> &get_preorder();
+        std::vector<int> &get_idom();
+        std::map<int, std::vector<int>> &get_idom_map();
+        std::vector<int> &get_postorder_idom_map();
+        int get_idom(int bb_id);
+        std::vector<int> get_idom_map(int bb_id);
+        int get_postorder_idom_map(int idom_id);
+        bool dominates(int bb1_id, int bb2_id);
+        bool is_reachable_from_entry(int bb_id);
+        void analyze();
+
+    private:
+        std::vector<int> idom;
+        std::map<int, std::vector<int>> idom_map;
+        std::vector<int> postorder_idom;
+        std::vector<int> postorder;
+        std::vector<int> postorder_bb_map;
+        std::vector<int> preorder;
+        std::vector<int> preorder_bb_map;
+        void reverse_cfg();
+        void postorder_idom_helper(std::vector<bool> &visited, int id);
+        void postorder_dfs_helper(std::vector<bool> &visited_bbs, int id, int depth);
+        void postorder_dfs(bool reverse_cfg);
+        void preorder_dfs_helper(std::vector<bool> &visited_bbs, int id);
+        void preorder_dfs(bool reverse_cfg);
+        int intersect(int bb1_id, int bb2_id);
+};
+
+void dump(dominator_analysis &dom);
+} // namespace block
+
+#endif

include/builder/builder_context.h

@@ -1,6 +1,7 @@
 #ifndef BUILDER_CONTEXT
 #define BUILDER_CONTEXT
 #include "blocks/basic_blocks.h"
+#include "blocks/dominance.h"
 #include "blocks/expr.h"
 #include "blocks/stmt.h"
 #include "builder/forward_declarations.h"