diff --git a/include/luisa/luisa-compute.h b/include/luisa/luisa-compute.h
index 5454cb365..235b67368 100644
--- a/include/luisa/luisa-compute.h
+++ b/include/luisa/luisa-compute.h
@@ -237,9 +237,11 @@
 #include <luisa/xir/metadata/location.h>
 #include <luisa/xir/metadata/name.h>
 #include <luisa/xir/module.h>
+#include <luisa/xir/passes/aggregate_field_bitmask.h>
 #include <luisa/xir/passes/dce.h>
 #include <luisa/xir/passes/dom_tree.h>
 #include <luisa/xir/passes/outline.h>
+#include <luisa/xir/passes/ref_arg_usage.h>
 #include <luisa/xir/passes/sink_alloca.h>
 #include <luisa/xir/passes/trace_gep.h>
 #include <luisa/xir/pool.h>
diff --git a/src/xir/passes/aggregate_field_bitmask.h b/include/luisa/xir/passes/aggregate_field_bitmask.h
similarity index 69%
rename from src/xir/passes/aggregate_field_bitmask.h
rename to include/luisa/xir/passes/aggregate_field_bitmask.h
index 5a5c2de34..e4a3df166 100644
--- a/src/xir/passes/aggregate_field_bitmask.h
+++ b/include/luisa/xir/passes/aggregate_field_bitmask.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <luisa/core/dll_export.h>
 #include <luisa/core/stl/memory.h>
 
 namespace luisa::compute {
@@ -12,7 +13,7 @@ namespace detail {
 class AggregateFieldTree;
 }// namespace detail
 
-class alignas(16) AggregateFieldBitmask {
+class LC_XIR_API alignas(16) AggregateFieldBitmask {
 
 private:
     const detail::AggregateFieldTree *_field_tree;
@@ -43,7 +44,7 @@ class alignas(16) AggregateFieldBitmask {
     [[nodiscard]] const Type *type() const noexcept;
 
 public:
-    class ConstBitSpan {
+    class LC_XIR_API ConstBitSpan {
     protected:
         uint64_t *_bits;
         uint32_t _offset;
@@ -51,15 +52,32 @@ class alignas(16) AggregateFieldBitmask {
     public:
         ConstBitSpan(uint64_t *bits, uint32_t offset, uint32_t size) noexcept
             : _bits{bits}, _offset{offset}, _size{size} {}
+        [[nodiscard]] const uint64_t *raw_bits() const noexcept { return _bits; }
+        [[nodiscard]] size_t offset() const noexcept { return _offset; }
+        [[nodiscard]] size_t size() const noexcept { return _size; }
         [[nodiscard]] bool all() const noexcept;
         [[nodiscard]] bool any() const noexcept;
         [[nodiscard]] bool none() const noexcept;
     };
-    class BitSpan : public ConstBitSpan {
+    class LC_XIR_API BitSpan : public ConstBitSpan {
     public:
         using ConstBitSpan::ConstBitSpan;
-        void set(bool value = true) && noexcept;
-        void flip() && noexcept;
+        [[nodiscard]] uint64_t *raw_bits() noexcept { return _bits; }
+
+        void set(bool value = true) noexcept;
+        void flip() noexcept;
+
+        BitSpan &operator|=(const ConstBitSpan &rhs) noexcept;
+        BitSpan &operator&=(const ConstBitSpan &rhs) noexcept;
+        BitSpan &operator^=(const ConstBitSpan &rhs) noexcept;
+        [[nodiscard]] bool operator==(const ConstBitSpan &rhs) const noexcept;
+        [[nodiscard]] bool operator!=(const ConstBitSpan &rhs) const noexcept;
+
+        BitSpan &operator|=(const AggregateFieldBitmask &rhs) noexcept { return *this |= rhs.access(); }
+        BitSpan &operator&=(const AggregateFieldBitmask &rhs) noexcept { return *this &= rhs.access(); }
+        BitSpan &operator^=(const AggregateFieldBitmask &rhs) noexcept { return *this ^= rhs.access(); }
+        [[nodiscard]] bool operator==(const AggregateFieldBitmask &rhs) const noexcept { return *this == rhs.access(); }
+        [[nodiscard]] bool operator!=(const AggregateFieldBitmask &rhs) const noexcept { return *this != rhs.access(); }
     };
     [[nodiscard]] BitSpan access(luisa::span<const size_t> access_chain) noexcept;
     [[nodiscard]] ConstBitSpan access(luisa::span<const size_t> access_chain) const noexcept;
diff --git a/include/luisa/xir/passes/ref_arg_usage.h b/include/luisa/xir/passes/ref_arg_usage.h
new file mode 100644
index 000000000..a3b2f78d7
--- /dev/null
+++ b/include/luisa/xir/passes/ref_arg_usage.h
@@ -0,0 +1,7 @@
+#pragma once
+
+namespace luisa::compute::xir {
+
+
+
+}
diff --git a/src/xir/CMakeLists.txt b/src/xir/CMakeLists.txt
index f106dc833..8398bb8ed 100644
--- a/src/xir/CMakeLists.txt
+++ b/src/xir/CMakeLists.txt
@@ -56,6 +56,7 @@ set(LUISA_COMPUTE_XIR_SOURCES
         passes/sink_alloca.cpp
         passes/trace_gep.cpp
         passes/aggregate_field_bitmask.cpp
+        passes/ref_arg_usage.cpp
 )
 
 add_library(luisa-compute-xir SHARED ${LUISA_COMPUTE_XIR_SOURCES})
diff --git a/src/xir/passes/aggregate_field_bitmask.cpp b/src/xir/passes/aggregate_field_bitmask.cpp
index 046f1b1be..d61e9163d 100644
--- a/src/xir/passes/aggregate_field_bitmask.cpp
+++ b/src/xir/passes/aggregate_field_bitmask.cpp
@@ -3,8 +3,7 @@
 #include <luisa/core/stl/vector.h>
 #include <luisa/core/stl/unordered_map.h>
 #include <luisa/ast/type.h>
-
-#include "aggregate_field_bitmask.h"
+#include <luisa/xir/passes/aggregate_field_bitmask.h>
 
 namespace luisa::compute::xir {
 
@@ -211,7 +210,7 @@ void AggregateFieldBitmask::flip() noexcept {
     }
 }
 
-void AggregateFieldBitmask::BitSpan::set(bool value) && noexcept {
+void AggregateFieldBitmask::BitSpan::set(bool value) noexcept {
     auto lower = _offset / 64u;
     auto upper = (_offset + _size - 1u) / 64u;
     if (lower == upper) {// all selected bits are in the same bucket
@@ -252,7 +251,7 @@ void AggregateFieldBitmask::BitSpan::set(bool value) && noexcept {
     }
 }
 
-void AggregateFieldBitmask::BitSpan::flip() && noexcept {
+void AggregateFieldBitmask::BitSpan::flip() noexcept {
     auto lower = _offset / 64u;
     auto upper = (_offset + _size - 1u) / 64u;
     if (lower == upper) {// all selected bits are in the same bucket
@@ -277,6 +276,56 @@ void AggregateFieldBitmask::BitSpan::flip() && noexcept {
     }
 }
 
+// TODO: Implement the following methods in a SIMD-friendly way
+AggregateFieldBitmask::BitSpan &AggregateFieldBitmask::BitSpan::operator|=(const ConstBitSpan &rhs) noexcept {
+    LUISA_DEBUG_ASSERT(_size == rhs.size(), "Size mismatch.");
+    for (auto i = 0u; i < _size; i++) {
+        if (auto rhs_bucket = rhs.raw_bits()[(i + rhs.offset()) / 64u];
+            (rhs_bucket >> ((i + rhs.offset()) % 64u)) & 1ull) {
+            _bits[(_offset + i) / 64u] |= 1ull << ((_offset + i) % 64u);
+        }
+    }
+    return *this;
+}
+
+AggregateFieldBitmask::BitSpan &AggregateFieldBitmask::BitSpan::operator&=(const ConstBitSpan &rhs) noexcept {
+    LUISA_DEBUG_ASSERT(_size == rhs.size(), "Size mismatch.");
+    for (auto i = 0u; i < _size; i++) {
+        if (auto rhs_bucket = rhs.raw_bits()[(i + rhs.offset()) / 64u];
+            (rhs_bucket >> ((i + rhs.offset()) % 64u)) & 1ull) {
+            _bits[(_offset + i) / 64u] &= 1ull << ((_offset + i) % 64u);
+        }
+    }
+    return *this;
+}
+
+AggregateFieldBitmask::BitSpan &AggregateFieldBitmask::BitSpan::operator^=(const ConstBitSpan &rhs) noexcept {
+    LUISA_DEBUG_ASSERT(_size == rhs.size(), "Size mismatch.");
+    for (auto i = 0u; i < _size; i++) {
+        if (auto rhs_bucket = rhs.raw_bits()[(i + rhs.offset()) / 64u];
+            (rhs_bucket >> ((i + rhs.offset()) % 64u)) & 1ull) {
+            _bits[(_offset + i) / 64u] ^= 1ull << ((_offset + i) % 64u);
+        }
+    }
+    return *this;
+}
+
+bool AggregateFieldBitmask::BitSpan::operator==(const ConstBitSpan &rhs) const noexcept {
+    if (_size != rhs.size()) { return false; }
+    if (this != &rhs) {
+        for (auto i = 0u; i < _size; i++) {
+            auto lhs_bit = (_bits[(_offset + i) / 64u] >> ((_offset + i) % 64u)) & 1ull;
+            auto rhs_bit = (rhs.raw_bits()[i / 64u] >> (i % 64u)) & 1ull;
+            if (lhs_bit != rhs_bit) { return false; }
+        }
+    }
+    return true;
+}
+
+bool AggregateFieldBitmask::BitSpan::operator!=(const ConstBitSpan &rhs) const noexcept {
+    return !(*this == rhs);
+}
+
 bool AggregateFieldBitmask::ConstBitSpan::all() const noexcept {
     auto lower = _offset / 64u;
     auto upper = (_offset + _size - 1u) / 64u;
diff --git a/src/xir/passes/ref_arg_usage.cpp b/src/xir/passes/ref_arg_usage.cpp
new file mode 100644
index 000000000..92ef23689
--- /dev/null
+++ b/src/xir/passes/ref_arg_usage.cpp
@@ -0,0 +1,5 @@
+#include <luisa/xir/passes/ref_arg_usage.h>
+
+namespace luisa::compute::xir {
+
+}// namespace luisa::compute::xir
diff --git a/src/xir/tests/test_aggregate_field_bitmasks.cpp b/src/xir/tests/test_aggregate_field_bitmasks.cpp
index 39bf83881..23614f4ae 100644
--- a/src/xir/tests/test_aggregate_field_bitmasks.cpp
+++ b/src/xir/tests/test_aggregate_field_bitmasks.cpp
@@ -1,6 +1,4 @@
 #include <luisa/luisa-compute.h>
-#include "../passes/aggregate_field_bitmask.h"
-#include "luisa/dsl/struct.h"
 
 using namespace luisa;
 using namespace luisa::compute;