diff --git a/llvm/lib/Transforms/Scalar/JumpThreading.cpp b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
index 415136b612ac2..602228bcb8289 100644
--- a/llvm/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/llvm/lib/Transforms/Scalar/JumpThreading.cpp
@@ -2789,6 +2789,13 @@ void JumpThreadingPass::unfoldSelectInstr(BasicBlock *Pred, BasicBlock *BB,
   PredTerm->removeFromParent();
   PredTerm->insertInto(NewBB, NewBB->end());
   // Create a conditional branch and update PHI nodes.
+  //
+  // Note: Technically we should `freeze` the condition before using it in a
+  // conditional branch, unless we can prove it's not poison: select-on-on
+  // poison isn't UB, but branch-on-poison is.  But doing this causes
+  // performance regressions, and we haven't been able to find a source-level
+  // correctness issue it fixes.  See
+  // https://github.com/llvm/llvm-project/pull/199408#issuecomment-4545013881.
   auto *BI = CondBrInst::Create(SI->getCondition(), NewBB, BB, Pred);
   BI->applyMergedLocation(PredTerm->getDebugLoc(), SI->getDebugLoc());
   BI->copyMetadata(*SI, {LLVMContext::MD_prof});