diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 7ef6955..9443653 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -335,6 +335,7 @@
     }
 
     // If not found or previously deleted, create and cache a new instruction.
+    // Don't bother reviving a previously deleted instruction, for simplicity.
     if (constant == nullptr || constant->GetBlock() == nullptr) {
       constant = new (arena_) InstructionType(value);
       cache->Overwrite(value, constant);