diff --git a/include/luisa/xir/instructions/break.h b/include/luisa/xir/instructions/break.h
index 16a86ecde..c629d8043 100644
--- a/include/luisa/xir/instructions/break.h
+++ b/include/luisa/xir/instructions/break.h
@@ -14,4 +14,4 @@ class LC_XIR_API BreakInst : public Instruction {
     }
 };
 
-}
+}// namespace luisa::compute::xir
diff --git a/include/luisa/xir/instructions/continue.h b/include/luisa/xir/instructions/continue.h
index cb4c7603e..452b643bd 100644
--- a/include/luisa/xir/instructions/continue.h
+++ b/include/luisa/xir/instructions/continue.h
@@ -13,4 +13,4 @@ class LC_XIR_API ContinueInst : public Instruction {
     }
 };
 
-}
\ No newline at end of file
+}// namespace luisa::compute::xir
\ No newline at end of file
diff --git a/include/luisa/xir/instructions/switch.h b/include/luisa/xir/instructions/switch.h
index 8426610c8..d224f3ed0 100644
--- a/include/luisa/xir/instructions/switch.h
+++ b/include/luisa/xir/instructions/switch.h
@@ -4,6 +4,17 @@
 
 namespace luisa::compute::xir {
 
+// Switch instruction:
+//
+// switch (value) {
+//   case case_values[0]: { case_blocks[0] }
+//   case case_values[1]: { case_blocks[1] }
+//   ...
+//   default: { default_block }
+// }
+// { merge_block }
+//
+// Note: this instruction must be the terminator of a basic block.
 class LC_XIR_API SwitchInst : public Instruction {
 
 public:
diff --git a/src/xir/instructions/loop.cpp b/src/xir/instructions/loop.cpp
index cbdbb89bd..046f4dcf0 100644
--- a/src/xir/instructions/loop.cpp
+++ b/src/xir/instructions/loop.cpp
@@ -66,4 +66,4 @@ const BasicBlock *LoopInst::merge_block() const noexcept {
     return const_cast<LoopInst *>(this)->merge_block();
 }
 
-}// namespace luisa::compute::xir
\ No newline at end of file
+}// namespace luisa::compute::xir