WIP v2: Add infra to construct a while loop using the loop_info analysis (36/43 tests pass)

Author: VedantParanjape

include/blocks/basic_blocks.h

@@ -4,6 +4,7 @@
 #include <vector>
 #include <deque>
 #include <string>
+#include <map>
 
 class basic_block {
     public:
@@ -18,6 +19,7 @@ class basic_block {
         unsigned int ast_depth;
         unsigned int id;
         std::string name;
+        // static std::map<block::stmt::Ptr, std::shared_ptr<basic_block>> ast_to_basic_block_map;
 };
 
 basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast);

include/blocks/loops.h

@@ -40,6 +40,7 @@ class loop_info {
     std::shared_ptr<loop> allocate_loop(std::shared_ptr<basic_block> header);
     block::stmt_block::Ptr convert_to_ast(block::stmt_block::Ptr ast);
     std::map<unsigned int, std::vector<int>> postorder_loops_map;
+    std::map<unsigned int, std::vector<int>> preorder_loops_map;
     std::vector<std::shared_ptr<loop>> loops;
     std::vector<std::shared_ptr<loop>> top_level_loops;
 
@@ -48,6 +49,7 @@ class loop_info {
     dominator_analysis dta;
     std::map<int, std::shared_ptr<loop>> bb_loop_map;
     void postorder_dfs_helper(std::vector<int> &postorder_loops_map, std::vector<bool> &visited_loops, int id);
+    void preorder_dfs_helper(std::vector<int> &preorder_loops_map, std::vector<bool> &visited_loops, int id);
     // discover loops during traversal of the abstract syntax tree
     void analyze();
 };

src/blocks/basic_blocks.cpp

@@ -13,6 +13,7 @@ basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast) {
     for (auto st: ast->stmts) {
         auto bb = std::make_shared<basic_block>(std::to_string(basic_block_count));
         bb->parent = st;
+        // bb->ast_to_basic_block_map[bb->parent] = bb;
         bb->ast_index = ast_index_counter++;
         bb->ast_depth = 0;
         work_list.push_back(bb);
@@ -40,6 +41,7 @@ basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast) {
                 for (auto st: stmt_block_->stmts) {
                     stmt_block_list.push_back(std::make_shared<basic_block>(std::to_string(basic_block_count++)));
                     stmt_block_list.back()->parent = st;
+                    // stmt_block_list.back()->ast_to_basic_block_map[bb->parent] = stmt_block_list.back();
                     stmt_block_list.back()->ast_index = ast_index_counter++;
                     stmt_block_list.back()->ast_depth = bb->ast_depth + 1;
                 }
@@ -79,6 +81,8 @@ basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast) {
             auto exit_bb = std::make_shared<basic_block>("exit" + std::to_string(basic_block_count));
             // assign it a empty stmt_block as parent
             exit_bb->parent = std::make_shared<stmt_block>();
+            // add mapping in ast to bb map
+            // exit_bb->ast_to_basic_block_map[exit_bb->parent] = exit_bb;
             // set the ast depth of the basic block
             exit_bb->ast_depth = bb->ast_depth;
             // check if this is the last block, if yes the successor will be empty
@@ -98,6 +102,8 @@ basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast) {
                 auto then_bb = std::make_shared<basic_block>(std::to_string(++basic_block_count));
                 // set the parent of this block as the then stmts
                 then_bb->parent = if_stmt_->then_stmt;
+                // add mapping in ast to bb map
+                // then_bb->ast_to_basic_block_map[then_bb->parent] = then_bb;
                 // set the ast depth of the basic block
                 then_bb->ast_depth = bb->ast_depth;
                 // set the successor of this block to be the exit block
@@ -112,6 +118,8 @@ basic_block::cfg_block generate_basic_blocks(block::stmt_block::Ptr ast) {
                 auto else_bb = std::make_shared<basic_block>(std::to_string(++basic_block_count));
                 // set the parent of this block as the else stmts
                 else_bb->parent = if_stmt_->else_stmt;
+                // add mapping in ast to bb map
+                // else_bb->ast_to_basic_block_map[else_bb->parent] = else_bb;
                 // set the ast depth of the basic block
                 else_bb->ast_depth = bb->ast_depth;
                 // set the successor of this block to be the exit block