diff --git a/crates/oxide_bytecode/src/opcode.rs b/crates/oxide_bytecode/src/opcode.rs
index f055e754..aae6429c 100644
--- a/crates/oxide_bytecode/src/opcode.rs
+++ b/crates/oxide_bytecode/src/opcode.rs
@@ -159,22 +159,22 @@ define_opcodes! {
     // ── Arithmetic (0x00-0x0F) ──
     ADD = 0x00 => "ADD",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     SUB = 0x01 => "SUB",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     MUL = 0x02 => "MUL",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     DIV = 0x03 => "DIV",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     MOD = 0x04 => "MOD",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     NEG = 0x05 => "NEG",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     COMPOUND_ADD = 0x06 => "COMPOUND_ADD",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::Rd), SlotSpec::Slot(Slot::A)],
         pure = false, jump = false, term = false, ic = false,
@@ -196,7 +196,7 @@ define_opcodes! {
     // 二元幂运算 `a ** b`（三寄存器，与 SUB/MUL 同族；0x00-0x0F 已满，值用空闲槽 0x94）。
     EXP = 0x94 => "EXP",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     MOV = 0x0C => "MOV", // rd=dst, a=src（寄存器复制，区间拆分搬值）
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A)],
         pure = true, jump = false, term = false, ic = false,
@@ -213,22 +213,22 @@ define_opcodes! {
     // ── 比较 (0x10-0x1F) ──
     EQ = 0x10 => "EQ",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     NEQ = 0x11 => "NEQ",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     LT = 0x12 => "LT",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     GT = 0x13 => "GT",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     LTE = 0x14 => "LTE",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     GTE = 0x15 => "GTE",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     IN = 0x16 => "IN",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
         pure = false, jump = false, term = false, ic = false,
@@ -249,7 +249,7 @@ define_opcodes! {
         pure = true, jump = false, term = false, ic = false,
     UNARY_PLUS = 0x1D => "UNARY_PLUS",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
 
     // ── 控制流 (0x1E-0x2F) ──
     BREAK = 0x1E => "BREAK",
@@ -330,7 +330,7 @@ define_opcodes! {
     // ── 模板字符串 (0x38) ──
     TEMPLATE_STR = 0x38 => "TEMPLATE_STR",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::TemplateExprs],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
 
     // ── 标签模板对象 (0x97) ──
     // GetTemplateObject：按 site 缓存模板对象（同一编译树同 site 恒返回同一对象），
@@ -473,10 +473,10 @@ define_opcodes! {
         pure = false, jump = false, term = false, ic = false,
     // 多操作数拼接（连续 `+` 左结合链摊平）：rd=结果，a=首操作数，ext=[n, op2..opn]，
     // n=操作数总数，ext 字数 = 1+(n-1) = n；op 字无高位标记（纯 vreg，≤255），
-    // SpreadArgs 直接解析。与 ADD 同标纯（含 ToPrimitive 副作用仍静态可删，语义同 ADD）。
+    // SpreadArgs 直接解析。含 ToPrimitive 副作用，不可删。
     CONCAT_N = 0x93 => "CONCAT_N",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::SpreadArgs],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
 
     // ── 成员更新 (0x59-0x62) ──
     MEMBER_INC = 0x59 => "MEMBER_INC", // 结果写 a 槽（val 槽原地更新）
@@ -668,25 +668,25 @@ define_opcodes! {
     // ── 位运算 (0x80-0x8F) ──
     BIT_AND = 0x80 => "BIT_AND",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     BIT_OR = 0x81 => "BIT_OR",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     BIT_XOR = 0x82 => "BIT_XOR",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     SHL = 0x83 => "SHL",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     SHR = 0x84 => "SHR",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     USHR = 0x85 => "USHR",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A), SlotSpec::Slot(Slot::B)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     BIT_NOT = 0x86 => "BIT_NOT",
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::A)],
-        pure = true, jump = false, term = false, ic = false,
+        pure = false, jump = false, term = false, ic = false,
     TO_OBJECT = 0x87 => "TO_OBJECT", // rd 原地转换（读且写）
         def = Some(SlotSpec::Slot(Slot::Rd)), uses = [SlotSpec::Slot(Slot::Rd)],
         pure = false, jump = false, term = false, ic = false,
diff --git a/crates/oxide_compiler/tests/compile_expr_tests.rs b/crates/oxide_compiler/tests/compile_expr_tests.rs
index 7542afd0..e8bbae95 100644
--- a/crates/oxide_compiler/tests/compile_expr_tests.rs
+++ b/crates/oxide_compiler/tests/compile_expr_tests.rs
@@ -792,3 +792,12 @@ fn compile_delete_new_instanceof_in() {
     );
     assert!(module.bytecode.iter().any(|&i| opcode::opcode(i) == OpCode::IN), "in should emit IN");
 }
+
+#[test]
+fn compile_nonfinal_relational_comparison_kept() {
+    let module = compile_source("let s = 1; s <= 1; s + 1;");
+    assert!(
+        module.bytecode.iter().any(|&i| opcode::opcode(i) == OpCode::LTE),
+        "非末语句形 s <= 1 应保留 LTE 指令（结果虽未用，ToPrimitive 副作用不可删）"
+    );
+}
diff --git a/crates/oxide_dce/src/iter_sweep.rs b/crates/oxide_dce/src/iter_sweep.rs
index fef53f25..c52160e8 100644
--- a/crates/oxide_dce/src/iter_sweep.rs
+++ b/crates/oxide_dce/src/iter_sweep.rs
@@ -107,13 +107,12 @@ mod tests {
     use oxide_ir::inst::Inst;
     use oxide_ir::operand::Operand;
 
-    /// 线性死链：LOAD_CONST→ADD→结果丢弃，全删（剩 RETURN）。
+    /// 线性死链：LOAD_CONST→MOV→结果丢弃，全删（剩 RETURN）。
     #[test]
     fn linear_dead_chain_deleted() {
         let mut f = IRFunction::new();
         f.insts.push(Inst::load_const(Operand::Reg(0), 0)); // 0: r0 = const
-        f.insts
-            .push(Inst::new(OpCode::ADD, Operand::Reg(1), Operand::Reg(0), Operand::Reg(0))); // 1: r1 = r0 + r0
+        f.insts.push(Inst::inst_mov(Operand::Reg(1), Operand::Reg(0))); // 1: r1 = r0
         f.insts
             .push(Inst::new(OpCode::RETURN, Operand::Reg(2), Operand::None, Operand::None)); // 2: return r2
         let mut keep = vec![true; f.insts.len()];
@@ -175,13 +174,12 @@ mod tests {
         assert_eq!(keep, vec![false, true], "死 CREATE_CLOSURE 删，RETURN 保留");
     }
 
-    /// 连锁迭代：写链 LOAD_CONST→ADD→LOAD_CONST 全死，逐轮删除至不动点。
+    /// 连锁迭代：写链 LOAD_CONST→MOV→LOAD_CONST 全死，逐轮删除至不动点。
     #[test]
     fn chained_dead_writes_deleted_iteratively() {
         let mut f = IRFunction::new();
-        f.insts.push(Inst::load_const(Operand::Reg(0), 0)); // 0: r0（ADD 读，轮 2 删）
-        f.insts
-            .push(Inst::new(OpCode::ADD, Operand::Reg(1), Operand::Reg(0), Operand::Reg(0))); // 1: r1（轮 1 删）
+        f.insts.push(Inst::load_const(Operand::Reg(0), 0)); // 0: r0（MOV 读，轮 2 删）
+        f.insts.push(Inst::inst_mov(Operand::Reg(1), Operand::Reg(0))); // 1: r1（轮 1 删）
         f.insts.push(Inst::load_const(Operand::Reg(2), 2)); // 2: r2 无人读（轮 1 删）
         f.insts
             .push(Inst::new(OpCode::RETURN, Operand::Reg(5), Operand::None, Operand::None)); // 3
diff --git a/crates/oxide_dce/tests/precise_unit.rs b/crates/oxide_dce/tests/precise_unit.rs
index 3d9971f7..b43d8fac 100644
--- a/crates/oxide_dce/tests/precise_unit.rs
+++ b/crates/oxide_dce/tests/precise_unit.rs
@@ -31,18 +31,8 @@ fn run_precise(f: &mut IRFunction, after: &[&[u32]], reg_count: usize) {
 #[test]
 fn reuse_killed_dead_write_deleted() {
     let mut f = IRFunction::new();
-    f.insts.push(Inst::new(
-        oxide_bytecode::opcode::OpCode::ADD,
-        Operand::Reg(5),
-        Operand::Reg(1),
-        Operand::Reg(2),
-    ));
-    f.insts.push(Inst::new(
-        oxide_bytecode::opcode::OpCode::ADD,
-        Operand::Reg(5),
-        Operand::Reg(3),
-        Operand::Reg(4),
-    ));
+    f.insts.push(Inst::inst_mov(Operand::Reg(5), Operand::Reg(1)));
+    f.insts.push(Inst::inst_mov(Operand::Reg(5), Operand::Reg(3)));
     f.insts.push(Inst::new(
         oxide_bytecode::opcode::OpCode::RETURN,
         Operand::Reg(5),
@@ -51,7 +41,7 @@ fn reuse_killed_dead_write_deleted() {
     ));
     // inst_live_after = [{3,4}, {5}, {}]：inst0 def 5 在 live_after[0] 无 5（后写杀死）
     run_precise(&mut f, &[&[3, 4], &[5], &[]], 5);
-    assert_eq!(f.insts.len(), 2, "死写（前一个 ADD）应被删");
+    assert_eq!(f.insts.len(), 2, "死写（前一个 MOV）应被删");
 }
 
 /// 局部死 STORE_VAR 删除（四条件全满足）。
diff --git a/crates/oxide_ir/tests/contract_tests.rs b/crates/oxide_ir/tests/contract_tests.rs
index 9d268e78..2c484bac 100644
--- a/crates/oxide_ir/tests/contract_tests.rs
+++ b/crates/oxide_ir/tests/contract_tests.rs
@@ -252,16 +252,8 @@ fn regalloc_opcodes_def_use_contract() {
 #[test]
 fn pure_ops_are_deletable() {
     let f = IRFunction::new();
-    // 算术 / 比较 / 位 / 逻辑
-    assert!(Inst::new(OpCode::ADD, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::SUB, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::MUL, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::NEG, Operand::Reg(0), Operand::Reg(1), Operand::None).is_pure(&f));
-    assert!(Inst::new(OpCode::EQ, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    // 逻辑 / 严格相等（不抛，纯）
     assert!(Inst::new(OpCode::STRICT_EQ, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::LT, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::BIT_AND, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
-    assert!(Inst::new(OpCode::BIT_NOT, Operand::Reg(0), Operand::Reg(1), Operand::None).is_pure(&f));
     assert!(Inst::new(OpCode::AND, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
     assert!(Inst::new(OpCode::OR, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
     assert!(Inst::new(OpCode::NOT, Operand::Reg(0), Operand::Reg(1), Operand::None).is_pure(&f));
@@ -277,8 +269,6 @@ fn pure_ops_are_deletable() {
     assert!(Inst::create_closure(Operand::Reg(1), 0).is_pure(&f));
     assert!(Inst::new(OpCode::LOAD_UPVALUE, Operand::Reg(1), Operand::Imm(0), Operand::None).is_pure(&f));
     assert!(Inst::new(OpCode::CELL_GET, Operand::Reg(0), Operand::Reg(1), Operand::Imm(0)).is_pure(&f));
-    // 模板字符串
-    assert!(Inst::template_str(Operand::Reg(1), 1, 10, &[0x1234]).is_pure(&f));
     // RegAlloc 辅助：MOV 纯
     assert!(Inst::inst_mov(Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
     // LOAD_VAR 普通（a=Reg）纯
@@ -292,6 +282,16 @@ fn pure_ops_are_deletable() {
 #[test]
 fn impure_ops_are_not_deletable() {
     let f = IRFunction::new();
+    // 算术 / 比较 / 位 / 模板字符串（ToNumber/ToPrimitive 可抛，不可删）
+    assert!(!Inst::new(OpCode::ADD, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::SUB, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::MUL, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::NEG, Operand::Reg(0), Operand::Reg(1), Operand::None).is_pure(&f));
+    assert!(!Inst::new(OpCode::EQ, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::LT, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::BIT_AND, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
+    assert!(!Inst::new(OpCode::BIT_NOT, Operand::Reg(0), Operand::Reg(1), Operand::None).is_pure(&f));
+    assert!(!Inst::template_str(Operand::Reg(1), 1, 10, &[0x1234]).is_pure(&f));
     // getter / 写对象属性
     assert!(!Inst::ic_get(Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
     assert!(!Inst::new(OpCode::GET_PROP, Operand::Reg(0), Operand::Reg(1), Operand::Reg(2)).is_pure(&f));
@@ -440,7 +440,14 @@ fn assert_group(ops: &[OpCode], def: Option<u32>, uses: &[u32], pure: bool) {
 /// 每个 opcode 的 def/use/pure 与现有语义表一致（canonical rd=1, a=2, b=3）。
 #[test]
 fn opcode_semantics_golden_table() {
-    // 二元运算：def=rd, uses=[a,b]，纯
+    // 二元运算：def=rd, uses=[a,b]，纯（逻辑/严格相等不抛）
+    assert_group(
+        &[OpCode::AND, OpCode::OR, OpCode::STRICT_EQ, OpCode::STRICT_NEQ, OpCode::NULLISH],
+        Some(1),
+        &[2, 3],
+        true,
+    );
+    // 二元但不可删：ToNumber/ToPrimitive 可抛，或 coerce 有观察路径
     assert_group(
         &[
             OpCode::ADD,
@@ -454,31 +461,24 @@ fn opcode_semantics_golden_table() {
             OpCode::GT,
             OpCode::LTE,
             OpCode::GTE,
-            OpCode::AND,
-            OpCode::OR,
-            OpCode::STRICT_EQ,
-            OpCode::STRICT_NEQ,
             OpCode::BIT_AND,
             OpCode::BIT_OR,
             OpCode::BIT_XOR,
             OpCode::SHL,
             OpCode::SHR,
             OpCode::USHR,
-            OpCode::NULLISH,
+            OpCode::IN,
+            OpCode::INSTANCEOF,
+            OpCode::CREATE_REGEXP,
         ],
         Some(1),
         &[2, 3],
-        true,
-    );
-    // 二元但不可删：coerce 有观察路径
-    assert_group(&[OpCode::IN, OpCode::INSTANCEOF, OpCode::CREATE_REGEXP], Some(1), &[2, 3], false);
-    // 一元：def=rd, uses=[a]
-    assert_group(
-        &[OpCode::NEG, OpCode::NOT, OpCode::UNARY_PLUS, OpCode::BIT_NOT, OpCode::TYPEOF],
-        Some(1),
-        &[2],
-        true,
+        false,
     );
+    // 一元：def=rd, uses=[a]，纯（NOT/TYPEOF 不抛）
+    assert_group(&[OpCode::NOT, OpCode::TYPEOF], Some(1), &[2], true);
+    // 一元但不可删：ToNumber/ToPrimitive 可抛
+    assert_group(&[OpCode::NEG, OpCode::UNARY_PLUS, OpCode::BIT_NOT], Some(1), &[2], false);
     // 复合赋值：def=rd, uses=[rd,a]，不可删
     assert_group(
         &[
@@ -551,10 +551,10 @@ fn opcode_semantics_golden_table() {
     assert_contract(OpCode::THROW, None, &[1], false);
     assert_contract(OpCode::RETURN, None, &[1], false);
     assert_contract(OpCode::HALT, None, &[0], false);
-    // 模板字符串：表达式寄存器来自 ext
-    assert_contract(OpCode::TEMPLATE_STR, Some(1), &[5], true);
-    // 多操作数拼接：a 槽首操作数 + ext[1..] 后续操作数（SpreadArgs 解析）
-    assert_contract(OpCode::CONCAT_N, Some(1), &[2, 5, 9], true);
+    // 模板字符串：表达式寄存器来自 ext；ToPrimitive 可抛，不可删
+    assert_contract(OpCode::TEMPLATE_STR, Some(1), &[5], false);
+    // 多操作数拼接：a 槽首操作数 + ext[1..] 后续操作数（SpreadArgs 解析）；ToPrimitive 可抛，不可删
+    assert_contract(OpCode::CONCAT_N, Some(1), &[2, 5, 9], false);
     // 小语言特性
     assert_contract(OpCode::DELETE_PROP_STATIC, None, &[1], false);
     assert_contract(OpCode::DELETE_PROP_DYNAMIC, None, &[1, 3], false);