[midend-IVE]参考libdivide库，实现了魔数的正确求解，如果后续出错直接用API或者不要除法强度削弱了

src/include/midend/IR.h

@@ -864,6 +864,8 @@ public:
         return "shl";
       case kSra:
         return "ashr";
+      case kMulh:
+        return "mulh";
       default:
         return "Unknown";
     }