[PM] ADCE: Fix caching of analyses.

When this pass was originally ported, AA wasn't available for the
new PM. Now it is, so we can cache properly.

llvm-svn: 271303

1 files changed, 8 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Scalar/ADCE.cpp b/llvm/lib/Transforms/Scalar/ADCE.cpp
index 09cf77a0c08..1c9160e2869 100644
--- a/llvm/lib/Transforms/Scalar/ADCE.cpp
+++ b/llvm/lib/Transforms/Scalar/ADCE.cpp
@@ -146,9 +146,14 @@ static bool aggressiveDCE(Function& F) {
 }
 
 PreservedAnalyses ADCEPass::run(Function &F) {
-  if (aggressiveDCE(F))
-    return PreservedAnalyses::none();
-  return PreservedAnalyses::all();
+  if (!aggressiveDCE(F))
+    return PreservedAnalyses::all();
+
+  // FIXME: ADCE should also 'preserve the CFG'.
+  // The new pass manager has currently no way to do it.
+  auto PA = PreservedAnalyses();
+  PA.preserve<GlobalsAA>();
+  return PA;
 }
 
 namespace {