diff --git a/App/lib/core/Gen/Call/CallGenCBuiltin.vp b/App/lib/core/Gen/Call/CallGenCBuiltin.vp
index c41c144..04476ad 100644
--- a/App/lib/core/Gen/Call/CallGenCBuiltin.vp
+++ b/App/lib/core/Gen/Call/CallGenCBuiltin.vp
@@ -670,6 +670,16 @@ novirtual class CallGenCBuiltin(CallGenBase.CallGenBase):
                 if mod_nm2.id is not None and string.strcmp(mod_nm2.id, "ASM_DESCR") == 0: return self._resolve_register(at.attr)
             return ""
 
+        # 裸枚举名（不带 ASM_DESCR. / t. 前缀）：`op=[CLOBBER_MEMORY, CLOBBER_RAX]`。
+        # 只有确实解析成 ASM_DESCR 成员时才接受（_resolve_register 对未知名给不出非空串），
+        # 否则返回空串交由调用方按"未知约束"处理，避免把普通变量名误当约束串。
+        if k == ast.ASTKind.Name:
+            nm_b: ast.Name* = ast.Name*(node)
+            if nm_b.id is not None:
+                rs_b: str = self._resolve_register(nm_b.id)
+                if rs_b is not None and rs_b[0] != '\0': return rs_b
+            return ""
+
         # Constant: string constant
         if k == ast.ASTKind.Constant:
             cn: ast.Constant* = ast.Constant*(node)