{GVNHoist] Mark GlobalsAA as preserved by GVNHoist.

[a.elovikov]

I don't add a test here because it'll be added as part of https://reviews.llvm.org/D32015.

[sebpop]

LGTM. Thanks!

llvm/trunk/lib/Transforms/Scalar/GVNHoist.cpp

 // exit:
 //   ret void
 //===----------------------------------------------------------------------===//
 
 #include "llvm/Transforms/Scalar/GVN.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/GlobalsModRef.h"
 #include "llvm/Analysis/MemorySSA.h"
 #include "llvm/Analysis/MemorySSAUpdater.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils/Local.h"
 
 using namespace llvm;
 
public:
 
   void getAnalysisUsage(AnalysisUsage &AU) const override {
     AU.addRequired<DominatorTreeWrapperPass>();
     AU.addRequired<AAResultsWrapperPass>();
     AU.addRequired<MemoryDependenceWrapperPass>();
     AU.addRequired<MemorySSAWrapperPass>();
     AU.addPreserved<DominatorTreeWrapperPass>();
     AU.addPreserved<MemorySSAWrapperPass>();
+    AU.addPreserved<GlobalsAAWrapperPass>();
   }
 };
 } // namespace
 
 PreservedAnalyses GVNHoistPass::run(Function &F, FunctionAnalysisManager &AM) {
   DominatorTree &DT = AM.getResult<DominatorTreeAnalysis>(F);
   AliasAnalysis &AA = AM.getResult<AAManager>(F);
   MemoryDependenceResults &MD = AM.getResult<MemoryDependenceAnalysis>(F);
   MemorySSA &MSSA = AM.getResult<MemorySSAAnalysis>(F).getMSSA();
   GVNHoist G(&DT, &AA, &MD, &MSSA);
   if (!G.run(F))
     return PreservedAnalyses::all();
 
   PreservedAnalyses PA;
   PA.preserve<DominatorTreeAnalysis>();
   PA.preserve<MemorySSAAnalysis>();
+  PA.preserve<GlobalsAA>();
   return PA;
 }
 
 char GVNHoistLegacyPass::ID = 0;
 INITIALIZE_PASS_BEGIN(GVNHoistLegacyPass, "gvn-hoist",
                       "Early GVN Hoisting of Expressions", false, false)
 INITIALIZE_PASS_DEPENDENCY(MemoryDependenceWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(MemorySSAWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)
 INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
 INITIALIZE_PASS_END(GVNHoistLegacyPass, "gvn-hoist",
                     "Early GVN Hoisting of Expressions", false, false)
 
 FunctionPass *llvm::createGVNHoistPass() { return new GVNHoistLegacyPass(); }