diff --git a/llvm/lib/CodeGen/BranchFolding.cpp b/llvm/lib/CodeGen/BranchFolding.cpp
index fbf1504..f2d1bf0 100644
--- a/llvm/lib/CodeGen/BranchFolding.cpp
+++ b/llvm/lib/CodeGen/BranchFolding.cpp
@@ -606,6 +606,7 @@
   // instructions that would be deleted in the merge.
   MachineFunction *MF = MBB1->getParent();
   if (EffectiveTailLen >= 2 &&
+      // FIXME: Use Function::optForSize().
       MF->getFunction()->hasFnAttribute(Attribute::OptimizeForSize) &&
       (I1 == MBB1->begin() || I2 == MBB2->begin()))
     return true;