New and improved comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155229 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp
index 20f8b787597dc547dd92c562f1b211a1a88d92a4..1b306d6990ab98702d6915226fc7c77e6649df47 100644 (file)
--- a/lib/CodeGen/ScheduleDAGInstrs.cpp
+++ b/lib/CodeGen/ScheduleDAGInstrs.cpp
@@ -135,8 +135,8 @@ void ScheduleDAGInstrs::startBlock(MachineBasicBlock *bb) {
 }
 
 void ScheduleDAGInstrs::finishBlock() {
+  // Subclasses should no longer refer to the old block.
   BB = 0;
-  // Nothing to do.
 }
 
 /// Initialize the map with the number of registers.