PM: Check that loop passes preserve a basic set of analyses

A loop pass that didn't preserve this entire set of passes wouldn't
play well with other loop passes, since these are generally a basic
requirement to do any interesting transformations to a loop.

Adds a helper to get the set of analyses a loop pass should preserve,
and checks that any loop pass we run satisfies the requirement.

llvm-svn: 268444

1 files changed, 1 insertions, 1 deletions

diff --git a/llvm/unittests/Analysis/LoopPassManagerTest.cpp b/llvm/unittests/Analysis/LoopPassManagerTest.cpp
index 3cbe203e14d..5858e174aab 100644
--- a/llvm/unittests/Analysis/LoopPassManagerTest.cpp
+++ b/llvm/unittests/Analysis/LoopPassManagerTest.cpp
@@ -92,7 +92,7 @@ public:
   TestLoopInvalidatingPass(StringRef LoopName) : Name(LoopName) {}
 
   PreservedAnalyses run(Loop &L, AnalysisManager<Loop> &AM) {
-    return L.getName() == Name ? PreservedAnalyses::none()
+    return L.getName() == Name ? getLoopPassPreservedAnalyses()
                                : PreservedAnalyses::all();
   }