diff --git a/lib/CodeGen/MachineBlockFrequency.cpp b/lib/CodeGen/MachineBlockFrequency.cpp
index 0a77bdd..f3ee538 100644
--- a/lib/CodeGen/MachineBlockFrequency.cpp
+++ b/lib/CodeGen/MachineBlockFrequency.cpp
@@ -50,10 +50,10 @@
   return false;
 }
 
-/// getblockFreq - Return block frequency. Never return 0, value must be
-/// positive. Please note that initial frequency is equal to 1024. It means that
-/// we should not rely on the value itself, but only on the comparison to the
-/// other block frequencies. We do this to avoid using of floating points.
+/// getblockFreq - Return block frequency. Return 0 if we don't have the
+/// information. Please note that initial frequency is equal to 1024. It means
+/// that we should not rely on the value itself, but only on the comparison to
+/// the other block frequencies. We do this to avoid using of floating points.
 ///
 uint32_t MachineBlockFrequency::getBlockFreq(MachineBasicBlock *MBB) {
   return MBFI->getBlockFreq(MBB);