[llvm] r271307 - [PM] BDCE: Fix caching of analyses.

[Davide Italiano via llvm-commits]

Author: davide
Date: Tue May 31 12:53:22 2016
New Revision: 271307

URL: http://llvm.org/viewvc/llvm-project?rev=271307&view=rev
Log:
[PM] BDCE: Fix caching of analyses.

Another chapter in the story. GlobalsAA should be preserved, as
 well as the CFG.

Modified:
    llvm/trunk/lib/Transforms/Scalar/BDCE.cpp

Modified: llvm/trunk/lib/Transforms/Scalar/BDCE.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/BDCE.cpp?rev=271307&r1=271306&r2=271307&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/BDCE.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/BDCE.cpp Tue May 31 12:53:22 2016
@@ -71,9 +71,14 @@ static bool bitTrackingDCE(Function &F,
 
 PreservedAnalyses BDCEPass::run(Function &F, FunctionAnalysisManager &AM) {
   auto &DB = AM.getResult<DemandedBitsAnalysis>(F);
-  if (bitTrackingDCE(F, DB))
-    return PreservedAnalyses::none();
-  return PreservedAnalyses::all();
+  if (!bitTrackingDCE(F, DB))
+    return PreservedAnalyses::all();
+
+  // FIXME: BDCE 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 {