diff --git a/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp b/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
index db1af57d9b5..6e6a776ea7e 100644
--- a/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
+++ b/lib/Transforms/Scalar/RewriteStatepointsForGC.cpp
@@ -1366,6 +1366,10 @@ makeStatepointExplicitImpl(const CallSite CS, /* to replace */
     Flags |= uint32_t(StatepointFlags::GCTransition);
     TransitionArgs = TransitionBundle->Inputs;
   }
+
+  // Instead of lowering calls to @llvm.experimental.deoptimize as normal calls
+  // with a return value, we lower then as never returning calls to
+  // __llvm_deoptimize that are followed by unreachable to get better codegen.
   bool IsDeoptimize = false;
 
   StatepointDirectives SD =