write phi elimination

src/opt/phieliminate.cpp

@@ -0,0 +1,72 @@
+#include "phieliminate.h"
+#include <stdexcept>
+#include "IR/IR_basic.h"
+
+using namespace opt;
+
+void ConductPhiEliminateForFunction([[maybe_unused]] std::shared_ptr<FunctionDefItem> func, CFGType &cfg) {
+  size_t new_block_cnt = 0;
+  for (auto cur_node : cfg.nodes) {
+    auto cur_block = cur_node->corresponding_block;
+    if (cur_block->actions.size() > 0) {
+      if (auto phi_act = std::dynamic_pointer_cast<PhiItem>(cur_block->actions[0])) {
+        // simple phi action caused by and, or and ternary operator, no need to insert extra blocks, just remove it and
+        // add phi values to the corresponding blocks
+        cur_block->actions.erase(cur_block->actions.begin());
+        for (auto [src_val, src_label] : phi_act->values) {
+          auto src_block = cfg.label_to_block[src_label];
+          auto new_move = std::make_shared<MoveInstruct>();
+          new_move->src_full = src_val;
+          new_move->dest_full = phi_act->result_full;
+          src_block->actions.push_back(new_move);
+        }
+      }
+    }
+    for (auto [_, phi_act] : cur_block->phi_map) {
+      for (auto [src_val, src_label] : phi_act->values) {
+        auto src_block = cfg.label_to_block[src_label];
+        auto src_node = cfg.block_to_node[src_block];
+        if (src_node->successors.size() > 1 && cur_node->predecessors.size() > 1) {
+          // it is a critical edge, need to insert a new block
+          auto new_block = std::make_shared<BlockItem>();
+          new_block->label_full = cur_block->label_full + ".phieliminate." + std::to_string(new_block_cnt++);
+          new_block->exit_action = std::make_shared<UNConditionJMPAction>();
+          std::dynamic_pointer_cast<UNConditionJMPAction>(new_block->exit_action)->label_full = cur_block->label_full;
+          auto src_block_exit_action = std::dynamic_pointer_cast<BRAction>(src_block->exit_action);
+          if (!src_block_exit_action) {
+            throw std::runtime_error(
+                "something strange happened: src block of a critical edge does not have a BRAction");
+          }
+          if (src_block_exit_action->true_label_full == cur_block->label_full) {
+            src_block_exit_action->true_label_full = new_block->label_full;
+          } else if (src_block_exit_action->false_label_full == cur_block->label_full) {
+            src_block_exit_action->false_label_full = new_block->label_full;
+          } else {
+            throw std::runtime_error(
+                "something strange happened: src block of a critical edge cannot find the corresponding label");
+          }
+          auto new_move = std::make_shared<MoveInstruct>();
+          new_move->src_full = src_val;
+          new_move->dest_full = phi_act->result_full;
+          new_block->actions.push_back(new_move);
+        } else {
+          auto new_move = std::make_shared<MoveInstruct>();
+          new_move->src_full = src_val;
+          new_move->dest_full = phi_act->result_full;
+          cur_block->actions.push_back(new_move);
+        }
+      }
+    }
+    cur_block->phi_map.clear();
+  }
+}
+
+std::shared_ptr<ModuleItem> PhiEliminate(std::shared_ptr<ModuleItem> src) {
+  auto res = src;
+  for (auto &func : res->function_defs) {
+    // func = std::make_shared<FunctionDefItem>(*func);
+    auto cfg = BuildCFGForFunction(func);
+    ConductPhiEliminateForFunction(func, cfg);
+  }
+  return res;
+}

src/opt/regalloc.cpp

@@ -0,0 +1 @@
+#include "regalloc.h"