When ScalarEvolution is told to forget the trip count for a loop, have

it also forget any SCEVs associated with loop-header PHIs in the loop,
as they may be dependent on trip count information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70633 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/Analysis/ScalarEvolution.h

@@ -333,6 +333,11 @@ namespace llvm {
     /// expression cannot be evaluated, return UnknownValue itself.
     SCEVHandle getSCEVAtScope(SCEV *S, const Loop *L);
 
+    /// forgetLoopPHIs - Delete the memoized SCEVs associated with the
+    /// PHI nodes in the given loop. This is used when the trip count of
+    /// the loop may have changed.
+    void forgetLoopPHIs(const Loop *L);
+
   public:
     static char ID; // Pass identification, replacement for typeid
     ScalarEvolution();