diff --git a/Cargo.lock b/Cargo.lock
index 9220d99e..0675f259 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1160,7 +1160,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_builtins"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "chrono",
  "fast-float",
@@ -1185,7 +1185,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_bytecode"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "num-bigint",
  "oxide_log",
@@ -1193,7 +1193,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cfg"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_emit",
@@ -1204,7 +1204,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_cli"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "ansi_term",
  "bumpalo",
@@ -1228,7 +1228,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_code_cache"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "lru",
  "oxide_bytecode",
@@ -1237,7 +1237,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_compiler"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1257,7 +1257,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_dce"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1271,7 +1271,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_emit"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "num-bigint",
  "oxc_allocator",
@@ -1287,7 +1287,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_engine"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1299,7 +1299,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_ir"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_log",
@@ -1308,7 +1308,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_kernel"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1322,7 +1322,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_liveness"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1334,7 +1334,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_log"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "tracing",
  "tracing-appender",
@@ -1343,11 +1343,11 @@ dependencies = [
 
 [[package]]
 name = "oxide_net"
-version = "0.16.19"
+version = "0.16.20"
 
 [[package]]
 name = "oxide_parser"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxc_allocator",
  "oxc_ast",
@@ -1362,7 +1362,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_regalloc"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_cfg",
@@ -1378,7 +1378,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_runtime_api"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "num-bigint",
  "num-traits",
@@ -1391,7 +1391,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_test262"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "oxide_bytecode",
  "oxide_compiler",
@@ -1411,7 +1411,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_types"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "bumpalo",
  "dashmap",
@@ -1424,7 +1424,7 @@ dependencies = [
 
 [[package]]
 name = "oxide_vm"
-version = "0.16.19"
+version = "0.16.20"
 dependencies = [
  "bumpalo",
  "chrono",
diff --git a/Cargo.toml b/Cargo.toml
index 2cf638ce..9783549c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,7 +24,7 @@ members = [
 ]
 
 [workspace.package]
-version = "0.16.19"
+version = "0.16.20"
 edition = "2021"
 license = "MIT"
 rust-version = "1.80"
diff --git a/crates/oxide_compiler/src/compiler.rs b/crates/oxide_compiler/src/compiler.rs
index 86f822ff..93d5a33d 100644
--- a/crates/oxide_compiler/src/compiler.rs
+++ b/crates/oxide_compiler/src/compiler.rs
@@ -2,7 +2,7 @@
 
 use oxide_bytecode::module::CompiledModule;
 use oxide_emit::Emitter;
-use oxide_ir::lower::lower;
+use oxide_ir::lower::lower_owned;
 
 /// 结构哈希 / 编译模块哈希 re-export（供编译缓存作键）。
 pub use crate::hash::{compiled_module_hash, structural_hash};
@@ -134,7 +134,7 @@ impl Compiler {
             crate::compiler_debug!("compile: after regalloc {} insts", ir.insts.len());
         }
         crate::compiler_debug!("compile: done, {} instructions", ir.insts.len());
-        let mut module = lower(&ir)?;
+        let mut module = lower_owned(ir)?;
         crate::flatten::flatten_submodules(&mut module);
         Ok(module)
     }
diff --git a/crates/oxide_ir/src/lower.rs b/crates/oxide_ir/src/lower.rs
index 3d6d5707..dc2c8194 100644
--- a/crates/oxide_ir/src/lower.rs
+++ b/crates/oxide_ir/src/lower.rs
@@ -13,8 +13,10 @@ use crate::inst::Inst;
 use crate::operand::Operand;
 use crate::IRFunction;
 
-/// IRFunction → CompiledModule 等价转换。溢出/标签错误消息串是下游解析的契约键，改动须同步更新下游匹配。
-pub fn lower(f: &IRFunction) -> Result<CompiledModule, String> {
+/// IRFunction → CompiledModule 等价转换（所有权版，编码单源）。
+/// 五个堆字段由克隆改为移动，nested 递归由借用改为移动；
+/// 产物字节码与借用版逐字节完全一致。溢出/标签错误消息串是下游解析的契约键，改动须同步更新下游匹配。
+pub fn lower_owned(f: IRFunction) -> Result<CompiledModule, String> {
     crate::ir_debug!("lower: {} insts", f.insts.len());
     // 常量池检查（先于寄存器——超大常量池伴生的海量 vreg 会使后续检查的
     // 稠密 bitset 表示爆内存；常量池超限是更基础的失效，先报它）
@@ -73,22 +75,22 @@ pub fn lower(f: &IRFunction) -> Result<CompiledModule, String> {
     }
 
     let mut sub_modules = Vec::with_capacity(f.nested.len());
-    for nested in &f.nested {
-        sub_modules.push(Arc::new(lower(nested)?));
+    for nested in f.nested {
+        sub_modules.push(Arc::new(lower_owned(nested)?));
     }
 
     Ok(CompiledModule {
         bytecode: Arc::from(instrs),
-        constants: f.constants.clone(),
+        constants: f.constants,
         n_registers: f.n_registers as u8,
         n_args: f.param_layout.count as u8,
         param_base: f.param_layout.base as u8,
-        builtin_reg_map: f.builtin_reg_map.clone(),
+        builtin_reg_map: f.builtin_reg_map,
         sub_modules,
         is_arrow: f.is_arrow,
         is_strict: f.is_strict,
         captured_this_const_idx: f.captured_this_const_idx,
-        function_name: f.function_name.clone(),
+        function_name: f.function_name,
         function_name_reg: f.function_name_reg,
         function_length: f.function_length,
         has_simple_params: f.has_simple_params,
@@ -97,14 +99,20 @@ pub fn lower(f: &IRFunction) -> Result<CompiledModule, String> {
         needs_home_object: f.needs_home_object,
         is_generator: f.is_generator,
         is_async: f.is_async,
-        upvalue_captures: f.upvalue_captures.clone(),
+        upvalue_captures: f.upvalue_captures,
         cells_needed: f.cells_needed,
-        cell_names: f.cell_names.clone(),
+        cell_names: f.cell_names,
         flat_id: 0,
         is_es_module: false,
     })
 }
 
+/// IRFunction → CompiledModule 等价转换（借用版，向后兼容既有调用点）。
+/// 委托所有权版：整结构克隆后移交，编码逻辑单源。
+pub fn lower(f: &IRFunction) -> Result<CompiledModule, String> {
+    lower_owned(f.clone())
+}
+
 /// Operand → u8 槽位。Const/Imm 在 a 槽走拆字（operand_pair_to_u8）；
 /// 出现在 b/rd 槽时按低字节直写（const_flag、cell_idx、uv_idx 等一字节立即数）。
 fn operand_to_u8(o: &Operand) -> u8 {