1 files changed, 25 insertions, 5 deletions

diff --git a/include/llvm/Transforms/Scalar/LoopPassManager.h b/include/llvm/Transforms/Scalar/LoopPassManager.h
index 715b11d3d974..473b97dc7e8d 100644
--- a/include/llvm/Transforms/Scalar/LoopPassManager.h
+++ b/include/llvm/Transforms/Scalar/LoopPassManager.h
@@ -164,10 +164,11 @@ public:
   /// If this is called for the current loop, in addition to clearing any
   /// state, this routine will mark that the current loop should be skipped by
   /// the rest of the pass management infrastructure.
-  void markLoopAsDeleted(Loop &L) {
-    LAM.clear(L);
-    assert(CurrentL->contains(&L) && "Cannot delete a loop outside of the "
-                                     "subloop tree currently being processed.");
+  void markLoopAsDeleted(Loop &L, llvm::StringRef Name) {
+    LAM.clear(L, Name);
+    assert((&L == CurrentL || CurrentL->contains(&L)) &&
+           "Cannot delete a loop outside of the "
+           "subloop tree currently being processed.");
     if (&L == CurrentL)
       SkipCurrentLoop = true;
   }
@@ -216,6 +217,19 @@ public:
     // shouldn't impact anything.
   }
 
+  /// Restart the current loop.
+  ///
+  /// Loop passes should call this method to indicate the current loop has been
+  /// sufficiently changed that it should be re-visited from the begining of
+  /// the loop pass pipeline rather than continuing.
+  void revisitCurrentLoop() {
+    // Tell the currently in-flight pipeline to stop running.
+    SkipCurrentLoop = true;
+
+    // And insert ourselves back into the worklist.
+    Worklist.insert(CurrentL);
+  }
+
 private:
   template <typename LoopPassT> friend class llvm::FunctionToLoopPassAdaptor;
 
@@ -271,13 +285,17 @@ public:
       return PA;
 
     // Get the analysis results needed by loop passes.
+    MemorySSA *MSSA = EnableMSSALoopDependency
+                          ? (&AM.getResult<MemorySSAAnalysis>(F).getMSSA())
+                          : nullptr;
     LoopStandardAnalysisResults LAR = {AM.getResult<AAManager>(F),
                                        AM.getResult<AssumptionAnalysis>(F),
                                        AM.getResult<DominatorTreeAnalysis>(F),
                                        AM.getResult<LoopAnalysis>(F),
                                        AM.getResult<ScalarEvolutionAnalysis>(F),
                                        AM.getResult<TargetLibraryAnalysis>(F),
-                                       AM.getResult<TargetIRAnalysis>(F)};
+                                       AM.getResult<TargetIRAnalysis>(F),
+                                       MSSA};
 
     // Setup the loop analysis manager from its proxy. It is important that
     // this is only done when there are loops to process and we have built the
@@ -345,6 +363,8 @@ public:
     PA.preserve<DominatorTreeAnalysis>();
     PA.preserve<LoopAnalysis>();
     PA.preserve<ScalarEvolutionAnalysis>();
+    // FIXME: Uncomment this when all loop passes preserve MemorySSA
+    // PA.preserve<MemorySSAAnalysis>();
     // FIXME: What we really want to do here is preserve an AA category, but
     // that concept doesn't exist yet.
     PA.preserve<AAManager>();