[AA] Preserve the AA results wrapper pass as well as BasicAA in a few

more places to prevent gratuitous re-"runs" of these passes.

The passes themselves don't do any work when run, but we keep spending
time scheduling and running these needlessly when we really don't need
to do so.

This is the first patch towards fixing the really horrible loop pass
pipeline fragmentation pointed out by Sanjoy in PR24804.

llvm-svn: 261302

1 files changed, 2 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/Utils/LCSSA.cpp b/llvm/lib/Transforms/Utils/LCSSA.cpp
index b4b2e14..0abb1f4 100644
--- a/llvm/lib/Transforms/Utils/LCSSA.cpp
+++ b/llvm/lib/Transforms/Utils/LCSSA.cpp
@@ -31,6 +31,7 @@
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
 #include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/LoopPass.h"
 #include "llvm/Analysis/ScalarEvolution.h"
@@ -298,6 +299,7 @@ struct LCSSA : public FunctionPass {
     AU.addRequired<LoopInfoWrapperPass>();
     AU.addPreservedID(LoopSimplifyID);
     AU.addPreserved<AAResultsWrapperPass>();
+    AU.addPreserved<BasicAAWrapperPass>();
     AU.addPreserved<GlobalsAAWrapperPass>();
     AU.addPreserved<ScalarEvolutionWrapperPass>();
     AU.addPreserved<SCEVAAWrapperPass>();