Lab4: Implement basic scalar optimizations and lower Phi nodes to assembly

src/ir/BasicBlock.cpp

@@ -42,4 +42,29 @@ const std::vector<BasicBlock*>& BasicBlock::GetSuccessors() const {
   return successors_;
 }
 
+void BasicBlock::EraseInstruction(Instruction* inst) {
+  for (auto it = instructions_.begin(); it != instructions_.end(); ++it) {
+    if (it->get() == inst) {
+      inst->ClearOperands();
+      instructions_.erase(it);
+      break;
+    }
+  }
+}
+
+void BasicBlock::InsertInstructionBefore(std::unique_ptr<Instruction> inst, Instruction* before) {
+  for (auto it = instructions_.begin(); it != instructions_.end(); ++it) {
+    if (it->get() == before) {
+      inst->SetParent(this);
+      instructions_.insert(it, std::move(inst));
+      break;
+    }
+  }
+}
+
+void BasicBlock::InsertInstructionAtBegin(std::unique_ptr<Instruction> inst) {
+  inst->SetParent(this);
+  instructions_.insert(instructions_.begin(), std::move(inst));
+}
+
 }  // namespace ir