begin to fix stupid Coalesce

src/opt/confgraph.cpp

@@ -286,6 +286,7 @@ void Simplify(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGraph &con
   confgraph.low_degree_and_not_move_related.erase(u);
   DetachNode(u, confgraph);
   confgraph.stack.push_back(u);
+  confgraph.awful_moves.clear();
 }
 
 void Coalesce(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGraph &confgraph) {
@@ -324,8 +325,10 @@ void Coalesce(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGraph &con
     }
     if (condition_satisfied) {
       MergeNodeInto(src_node, dest_node, confgraph);
+      confgraph.awful_moves.clear();
     } else {
       confgraph.potential_moves.insert(move);
+      confgraph.awful_moves.insert(move);
     }
   } else {
     // Briggs condition
@@ -342,8 +345,10 @@ void Coalesce(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGraph &con
     }
     if (dangerous_neighbors.size() < kMaxRegs) {
       MergeNodeInto(src_node, dest_node, confgraph);
+      confgraph.awful_moves.clear();
     } else {
       confgraph.potential_moves.insert(move);
+      confgraph.awful_moves.insert(move);
     }
   }
 }
@@ -362,6 +367,7 @@ void PotentailSpill(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGrap
   confgraph.high_degree_nodes.erase(u);
   DetachNode(u, confgraph);
   confgraph.stack.push_back(u);
+  confgraph.awful_moves.clear();
 }
 
 void GraphCheck(ConfGraph &confgraph) {
@@ -457,6 +463,7 @@ bool ConductColoring(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGra
     // std::cerr << "confgraph.low_degree_and_move_related.size()=" << confgraph.low_degree_and_move_related.size()
     //           << std::endl;
     // std::cerr << "confgraph.high_degree_nodes.size()=" << confgraph.high_degree_nodes.size() << std::endl;
+    // std::cerr << "confgraph.potential_moves.size()=" << confgraph.potential_moves.size() << std::endl;
     // std::cerr << "pending moves" << std::endl;
     // for (auto mode : confgraph.pending_moves) {
     //   std::cerr << '\t';
@@ -469,7 +476,7 @@ bool ConductColoring(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGra
     //   mode->RecursivePrint(std::cerr);
     // }
     // std::cerr << std::endl;
-    GraphCheck(confgraph);
+    // GraphCheck(confgraph);
     for (auto node : confgraph.low_degree_and_not_move_related) {
       if (node->is_binded_with_physical_reg) {
         throw std::runtime_error("something strange happened: node is binded with physical reg");
@@ -494,6 +501,9 @@ bool ConductColoring(std::shared_ptr<FunctionDefItem> src, CFGType &cfg, ConfGra
       if (confgraph.potential_moves.size() > 0) {
         std::vector<opt::MoveInstruct *> removed;
         for (auto move : confgraph.potential_moves) {
+          if (confgraph.awful_moves.find(move) != confgraph.awful_moves.end()) {
+            continue;
+          }
           auto src_node = confgraph.id_to_node[cfg.var_to_id[move->src_full]];
           auto dest_node = confgraph.id_to_node[cfg.var_to_id[move->dest_full]];
           src_node = ConfGraphNode::FindFather(src_node);

src/opt/regalloc.cpp

@@ -299,6 +299,34 @@ void TranslateColorResult(std::shared_ptr<FunctionDefItem> func, CFGType &cfg, C
     }
   }
 }
+
+void PairMoveEliminate(std::shared_ptr<FunctionDefItem> func, CFGType &cfg, ConfGraph &confgraph) {
+  for (auto node : cfg.nodes) {
+    auto block = node->corresponding_block;
+    auto it = block->actions.begin();
+    while (it != block->actions.end()) {
+      while (it != block->actions.end() && !std::dynamic_pointer_cast<opt::MoveInstruct>(*it)) {
+        ++it;
+      }
+      if (it == block->actions.end()) break;
+      std::unordered_map<std::string, std::list<std::shared_ptr<ActionItem>>::iterator> defined_by;
+      do {
+        auto cur_move = std::dynamic_pointer_cast<opt::MoveInstruct>(*it);
+        if (defined_by.find(cur_move->src_full) != defined_by.end() &&
+            std::dynamic_pointer_cast<opt::MoveInstruct>(*defined_by[cur_move->src_full])->src_full ==
+                cur_move->dest_full) {
+          auto it_next = it;
+          ++it_next;
+          block->actions.erase(it);
+          it = it_next;
+        } else {
+          defined_by[cur_move->dest_full] = it;
+          ++it;
+        }
+      } while (it != block->actions.end() && std::dynamic_pointer_cast<opt::MoveInstruct>(*it));
+    }
+  }
+}
 void ConductRegAllocForFunction(std::shared_ptr<FunctionDefItem> func) {
   std::cerr << "processing function " << func->func_name_raw << std::endl;
   CFGType cfg;
@@ -314,6 +342,7 @@ void ConductRegAllocForFunction(std::shared_ptr<FunctionDefItem> func) {
     confgraph = BuildConfGraph(cfg);
   } while (ConductColoring(func, cfg, confgraph));
   TranslateColorResult(func, cfg, confgraph);
+  // PairMoveEliminate(func, cfg, confgraph);
   func->RecursivePrint(std::cerr);
 }