1 files changed, 3 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/MIRParser/MILexer.cpp b/llvm/lib/CodeGen/MIRParser/MILexer.cpp
index d23df9c137b..ac696923794 100644
--- a/llvm/lib/CodeGen/MIRParser/MILexer.cpp
+++ b/llvm/lib/CodeGen/MIRParser/MILexer.cpp
@@ -277,6 +277,9 @@ static Cursor maybeLexMachineBasicBlock(Cursor C, MIToken &Token,
     C.advance();
   StringRef Number = NumberRange.upto(C);
   unsigned StringOffset = PrefixLength + Number.size(); // Drop '%bb.<id>'
+  // TODO: The format bb.<id>.<irname> is supported only when it's not a
+  // reference. Once we deprecate the format where the irname shows up, we
+  // should only lex forward if it is a reference.
   if (C.peek() == '.') {
     C.advance(); // Skip '.'
     ++StringOffset;