Add some comments noting how IndVarSimplify facilitates

LoopInfo functionality.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72091 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 6 insertions, 0 deletions

diff --git a/include/llvm/Analysis/LoopInfo.h b/include/llvm/Analysis/LoopInfo.h
index 69773a66ec..fb0b584d41 100644
--- a/include/llvm/Analysis/LoopInfo.h
+++ b/include/llvm/Analysis/LoopInfo.h
@@ -351,6 +351,9 @@ public:
   /// by one each time through the loop.  If so, return the phi node that
   /// corresponds to it.
   ///
+  /// The IndVarSimplify pass transforms loops to have a canonical induction
+  /// variable.
+  ///
   inline PHINode *getCanonicalInductionVariable() const {
     BlockT *H = getHeader();
 
@@ -406,6 +409,9 @@ public:
   /// of the loop executes N-1 times.  If the trip-count cannot be determined,
   /// this returns null.
   ///
+  /// The IndVarSimplify pass transforms loops to have a form that this
+  /// function easily understands.
+  ///
   inline Value *getTripCount() const {
     // Canonical loops will end with a 'cmp ne I, V', where I is the incremented
     // canonical induction variable and V is the trip count of the loop.