Add some more doxygen comments to SCEVAddRec.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70354 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/include/llvm/Analysis/ScalarEvolutionExpressions.h b/include/llvm/Analysis/ScalarEvolutionExpressions.h
index d94a9ebcb572c15c8299801f74cd8cda7eb07b4c..00cc40eb3173af4029841698b3ee494a02f99684 100644 (file)
--- a/include/llvm/Analysis/ScalarEvolutionExpressions.h
+++ b/include/llvm/Analysis/ScalarEvolutionExpressions.h
@@ -357,7 +357,10 @@ namespace llvm {
 
   //===--------------------------------------------------------------------===//
   /// SCEVAddRecExpr - This node represents a polynomial recurrence on the trip
-  /// count of the specified loop.
+  /// count of the specified loop.  This is the primary focus of the
+  /// ScalarEvolution framework; all the other SCEV subclasses are mostly just
+  /// supporting infrastructure to allow SCEVAddRecExpr expressions to be
+  /// created and analyzed.
   ///
   /// All operands of an AddRec are required to be loop invariant.
   ///