[backend] fix the logical error of constants in interference graph construction

src/RISCv64Backend.cpp

@@ -1121,6 +1121,35 @@ std::map<std::string, std::set<std::string>> RISCv64CodeGen::build_interference_
                 }
             }
         }
+        // --- 新增修复逻辑：处理指令内部操作数之间的干扰 ---
+        // 对于 store 指令，要存储的值和目标地址指针是同时活跃的，必须互相干扰。
+        if (auto store = dynamic_cast<StoreInst*>(inst)) {
+            Value* val_operand = store->getValue();
+            Value* ptr_operand = store->getPointer();
+
+            if (value_vreg_map.count(val_operand) && value_vreg_map.count(ptr_operand)) {
+                const std::string& val_vreg = value_vreg_map.at(val_operand);
+                const std::string& ptr_vreg = value_vreg_map.at(ptr_operand);
+                if (val_vreg != ptr_vreg) {
+                    graph[val_vreg].insert(ptr_vreg);
+                    graph[ptr_vreg].insert(val_vreg);
+                }
+            }
+        }
+        // 可选：为其他有两个或以上源操作数的指令（如 add）添加类似逻辑，
+        // 确保它们的操作数虚拟寄存器互相干扰。
+        else if (auto bin = dynamic_cast<BinaryInst*>(inst)) {
+             Value* lhs_operand = bin->getLhs();
+             Value* rhs_operand = bin->getRhs();
+             if (value_vreg_map.count(lhs_operand) && value_vreg_map.count(rhs_operand)) {
+                const std::string& lhs_vreg = value_vreg_map.at(lhs_operand);
+                const std::string& rhs_vreg = value_vreg_map.at(rhs_operand);
+                if (lhs_vreg != rhs_vreg) {
+                    graph[lhs_vreg].insert(rhs_vreg);
+                    graph[rhs_vreg].insert(rhs_vreg);
+                }
+             }
+        }
     }
     return graph;
 }