diff --git a/llvm/include/llvm/InitializePasses.h b/llvm/include/llvm/InitializePasses.h
--- a/llvm/include/llvm/InitializePasses.h
+++ b/llvm/include/llvm/InitializePasses.h
@@ -326,6 +326,7 @@
 void initializeModuleMemProfilerLegacyPassPass(PassRegistry &);
 void initializeModuleSummaryIndexWrapperPassPass(PassRegistry&);
 void initializeModuloScheduleTestPass(PassRegistry&);
+void initializeMSSAArgPromotionPass(PassRegistry &);
 void initializeMustExecutePrinterPass(PassRegistry&);
 void initializeMustBeExecutedContextPrinterPass(PassRegistry&);
 void initializeNameAnonGlobalLegacyPassPass(PassRegistry&);
diff --git a/llvm/include/llvm/Transforms/IPO.h b/llvm/include/llvm/Transforms/IPO.h
--- a/llvm/include/llvm/Transforms/IPO.h
+++ b/llvm/include/llvm/Transforms/IPO.h
@@ -158,6 +158,11 @@
 ///
 Pass *createArgumentPromotionPass(unsigned maxElements = 3);
 
+//===----------------------------------------------------------------------===//
+/// createMSSAArgPromotionPass - This pass promotes "by reference" arguments to
+/// be passed by value. Input or/and Output arguments supported.
+Pass *createMSSAArgPromotionPass();
+
 //===----------------------------------------------------------------------===//
 /// createOpenMPOptLegacyPass - OpenMP specific optimizations.
 Pass *createOpenMPOptCGSCCLegacyPass();
diff --git a/llvm/include/llvm/Transforms/IPO/MSSAArgPromotion.h b/llvm/include/llvm/Transforms/IPO/MSSAArgPromotion.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/Transforms/IPO/MSSAArgPromotion.h
@@ -0,0 +1,26 @@
+//===- MSSAArgPromotionPass.cpp - Promote by-reference arguments -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/CGSCCPassManager.h"
+#include "llvm/Analysis/LazyCallGraph.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+class MSSAArgPromotionPass : public PassInfoMixin<MSSAArgPromotionPass> {
+public:
+  MSSAArgPromotionPass() {}
+
+  PreservedAnalyses run(LazyCallGraph::SCC &C, CGSCCAnalysisManager &AM,
+                        LazyCallGraph &CG, CGSCCUpdateResult &UR);
+};
+
+} // end namespace llvm
diff --git a/llvm/lib/Passes/PassBuilder.cpp b/llvm/lib/Passes/PassBuilder.cpp
--- a/llvm/lib/Passes/PassBuilder.cpp
+++ b/llvm/lib/Passes/PassBuilder.cpp
@@ -111,6 +111,7 @@
 #include "llvm/Transforms/IPO/Internalize.h"
 #include "llvm/Transforms/IPO/LoopExtractor.h"
 #include "llvm/Transforms/IPO/LowerTypeTests.h"
+#include "llvm/Transforms/IPO/MSSAArgPromotion.h"
 #include "llvm/Transforms/IPO/MergeFunctions.h"
 #include "llvm/Transforms/IPO/ModuleInliner.h"
 #include "llvm/Transforms/IPO/OpenMPOpt.h"
diff --git a/llvm/lib/Passes/PassRegistry.def b/llvm/lib/Passes/PassRegistry.def
--- a/llvm/lib/Passes/PassRegistry.def
+++ b/llvm/lib/Passes/PassRegistry.def
@@ -161,6 +161,7 @@
 #define CGSCC_PASS(NAME, CREATE_PASS)
 #endif
 CGSCC_PASS("argpromotion", ArgumentPromotionPass())
+CGSCC_PASS("mssaargpromotion", MSSAArgPromotionPass())
 CGSCC_PASS("invalidate<all>", InvalidateAllAnalysesPass())
 CGSCC_PASS("function-attrs", PostOrderFunctionAttrsPass())
 CGSCC_PASS("attributor-cgscc", AttributorCGSCCPass())
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -47,6 +47,7 @@
 #include "llvm/Transforms/IPO/AlwaysInliner.h"
 #include "llvm/Transforms/IPO/GlobalDCE.h"
 #include "llvm/Transforms/IPO/Internalize.h"
+#include "llvm/Transforms/IPO/MSSAArgPromotion.h"
 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Scalar/GVN.h"
@@ -574,10 +575,14 @@
         PM.add(llvm::createAMDGPUSimplifyLibCallsPass(this));
   });
 
+  bool EnableAggressiveOpt = getOptLevel() >= CodeGenOpt::Aggressive;
   Builder.addExtension(
     PassManagerBuilder::EP_CGSCCOptimizerLate,
-    [EnableOpt, PromoteKernelArguments](const PassManagerBuilder &,
-                                        legacy::PassManagerBase &PM) {
+    [=](const PassManagerBuilder &, legacy::PassManagerBase &PM) {
+      // Add pass to promote arguments passed by reference
+      if (EnableAggressiveOpt)
+        PM.add(createMSSAArgPromotionPass());
+
       // Add promote kernel arguments pass to the opt pipeline right before
       // infer address spaces which is needed to do actual address space
       // rewriting.
@@ -737,6 +742,10 @@
           FPM.addPass(AMDGPUPromoteAllocaToVectorPass(*this));
         }
 
+        // Add pass to promote arguments passed by reference
+        if (Level.getSpeedupLevel() >= OptimizationLevel::O3.getSpeedupLevel())
+          PM.addPass(MSSAArgPromotionPass());
+
         PM.addPass(createCGSCCToFunctionPassAdaptor(std::move(FPM)));
       });
 }
diff --git a/llvm/lib/Transforms/IPO/CMakeLists.txt b/llvm/lib/Transforms/IPO/CMakeLists.txt
--- a/llvm/lib/Transforms/IPO/CMakeLists.txt
+++ b/llvm/lib/Transforms/IPO/CMakeLists.txt
@@ -30,6 +30,7 @@
   LowerTypeTests.cpp
   MergeFunctions.cpp
   ModuleInliner.cpp
+  MSSAArgPromotion.cpp
   OpenMPOpt.cpp
   PartialInlining.cpp
   PassManagerBuilder.cpp
diff --git a/llvm/lib/Transforms/IPO/IPO.cpp b/llvm/lib/Transforms/IPO/IPO.cpp
--- a/llvm/lib/Transforms/IPO/IPO.cpp
+++ b/llvm/lib/Transforms/IPO/IPO.cpp
@@ -47,6 +47,7 @@
   initializeSingleLoopExtractorPass(Registry);
   initializeLowerTypeTestsPass(Registry);
   initializeMergeFunctionsLegacyPassPass(Registry);
+  initializeMSSAArgPromotionPass(Registry);
   initializePartialInlinerLegacyPassPass(Registry);
   initializeAttributorLegacyPassPass(Registry);
   initializeAttributorCGSCCLegacyPassPass(Registry);
diff --git a/llvm/lib/Transforms/IPO/MSSAArgPromotion.cpp b/llvm/lib/Transforms/IPO/MSSAArgPromotion.cpp
new file mode 100755
--- /dev/null
+++ b/llvm/lib/Transforms/IPO/MSSAArgPromotion.cpp
@@ -0,0 +1,1413 @@
+//===------ MSSAArgPromotionPass.cpp - Promote by-reference arguments -----===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass promotes function argument passed by reference:
+//  1. Input argument: if the argument is read it is promoted to the argument
+//     passed by value. Callers load the argument's value and pass it to the
+//     function.
+//  2. Output argument: if the argument is modified the function return type is
+//     transformed into an aggregate and the final argument's value is returned
+//     as a component of the return value. Callers store the returned value
+//     using the original argument pointer.
+//  3. Input/Output argument: the combination of the above.
+//
+//  int foo(int a, int *x) {
+//    *x += 2;
+//    return a;
+//  }
+//  int MemVar;
+//  int X = foo(1, &MemVar);
+//
+//  into:
+//
+//  struct { int, int } foo (int a, int x) {
+//    return { a, x + 2 };
+//  }
+//  int MemVar;
+//  struct { int, int } S = foo(1, MemVar);
+//  int X = S.first;
+//  MemVar = S.second;
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Transforms/IPO/MSSAArgPromotion.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/Optional.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/ScopeExit.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/BasicAliasAnalysis.h"
+#include "llvm/Analysis/CGSCCPassManager.h"
+#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/Analysis/CaptureTracking.h"
+#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/IteratedDominanceFrontier.h"
+#include "llvm/Analysis/LazyCallGraph.h"
+#include "llvm/Analysis/Loads.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Analysis/MemoryLocation.h"
+#include "llvm/Analysis/MemorySSA.h"
+#include "llvm/Analysis/MemorySSAUpdater.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/TargetTransformInfo.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/Argument.h"
+#include "llvm/IR/Attributes.h"
+#include "llvm/IR/BasicBlock.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/IRPrintingPasses.h"
+#include "llvm/IR/InstrTypes.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Metadata.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/NoFolder.h"
+#include "llvm/IR/PassManager.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/Use.h"
+#include "llvm/IR/User.h"
+#include "llvm/IR/Value.h"
+#include "llvm/InitializePasses.h"
+#include "llvm/Pass.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Transforms/IPO.h"
+#include "llvm/Transforms/Utils/SSAUpdater.h"
+#include <algorithm>
+#include <cassert>
+#include <cstdint>
+#include <deque>
+#include <functional>
+#include <iterator>
+#include <map>
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+using namespace llvm;
+
+#define DEBUG_TYPE "mssaargpromotion"
+
+STATISTIC(NumInArgCandidates, "Number of input argument candidates found");
+STATISTIC(NumInArgPromoted, "Number of of input argument promoted");
+STATISTIC(NumInOutArgCandidates, "Number of in/out argument candidates found");
+STATISTIC(NumInOutArgPromoted, "Number of of in/out argument promoted");
+
+// When searching for a clobber for an argument we constrain the number of
+// expensive uncached MSSA walks.
+static cl::opt<unsigned> MaxMSSAWalksNum(
+    "argpromo-mssa-walks-limit", cl::Hidden, cl::init(10000),
+    cl::desc(
+        "Function argument promotion pass: the maximum number of MSSA walks"
+        " per argument on a clobber search (default = 1000)"));
+
+// Return dot prefixed string twine if S isn't empty (used for BB's names).
+static inline Twine dot(const StringRef &S) {
+  return !S.empty() ? Twine('.') + S : Twine();
+}
+
+// Structure describing argument for promotion.
+struct ArgPromotionInfo {
+  Argument *Arg;
+  Type *ArgType;
+  Align ArgAlign;
+  uint32_t Preload : 1; // Argument requires initial value to be passed to
+                        // the function.
+  uint32_t Return : 1;  // Argument should be returned by the function.
+
+  // When the argument is promoted we need a new argument for the incoming
+  // preloaded value but the new function signature isn't known yet and
+  // therefore isn't created. We use a dummy argument to start with and
+  // after the new function is created its RAUWed with the function's
+  // argument, see createNewFunction.
+  std::unique_ptr<Argument> PreloadArgDummy;
+
+  // Index of the value in the aggregated return type (insert/extract_value idx)
+  unsigned ReturnValueIndex = (unsigned)-1;
+
+  // If one candidate clobbers another this field denotes the relationship.
+  // Used to find "declobbering" promotion sequence.
+  ArgPromotionInfo *ClobberedBy = nullptr;
+
+  AAMDNodes AAMD; // Merged AA metadata for the load/store.
+
+  ArgPromotionInfo(Argument *Arg_ = nullptr, Type *ArgType_ = nullptr,
+                   Align ArgAlign_ = Align())
+      : Arg(Arg_), ArgType(ArgType_), ArgAlign(ArgAlign_) {
+    Preload = Return = 0;
+  }
+
+  unsigned getArgNo() const { return Arg->getArgNo(); }
+
+  bool isUnusedArg() const { return !Preload && !Return; }
+
+  // Return true if this argument is promoted.
+  bool isPromoted() const {
+    return PreloadArgDummy || ReturnValueIndex != (unsigned)-1;
+  }
+
+  // TODO: this is a placeholder for checking GEP indexes
+  bool isMyPtr(Value *Ptr) const { return Ptr && Ptr == Arg; }
+
+  // Predicates returning true if the value is a load or store by this
+  // argument (TODO: this will check GEPs later).
+  bool isMyLoad(Value *V) const {
+    LoadInst *LI = dyn_cast<LoadInst>(V);
+    return LI ? isMyPtr(LI->getPointerOperand()) : false;
+  }
+  bool isMyStore(Value *V) const {
+    StoreInst *SI = dyn_cast<StoreInst>(V);
+    return SI ? isMyPtr(SI->getPointerOperand()) : false;
+  }
+  bool isMyLoadOrStore(Value *V) const {
+    if (LoadInst *LI = dyn_cast<LoadInst>(V))
+      return isMyPtr(LI->getPointerOperand());
+    if (StoreInst *SI = dyn_cast<StoreInst>(V))
+      return isMyPtr(SI->getPointerOperand());
+    return false;
+  }
+
+  MemoryLocation getMemLoc() const {
+    const auto &DL = Arg->getParent()->getParent()->getDataLayout();
+    return MemoryLocation(Arg,
+                          LocationSize::precise(DL.getTypeStoreSize(ArgType)));
+  }
+
+  bool isClobberedBy(const ArgPromotionInfo &A) const {
+    const ArgPromotionInfo *P = this;
+    while ((P = P->ClobberedBy)) {
+      if (&A == P)
+        return true;
+    }
+    return false;
+  }
+
+  Twine getParamName(StringRef &&LifeTimeOwner = StringRef()) const {
+    // The problem with a twine is that StringRef it references should be alive
+    // when the twine is alive: use LifeTimeOwner to keep the StringRef alive
+    // at least for the lifetime of the full expression.
+    LifeTimeOwner = Arg->getName();
+    return LifeTimeOwner + ".0.val";
+  }
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+  LLVM_DUMP_METHOD StringRef getKindStr() const {
+    if (Preload && Return)
+      return "inout";
+    return Preload ? "in" : "out";
+  }
+#endif
+
+  Argument *getOrCreatePreloadArgDummy() {
+    if (!PreloadArgDummy)
+      PreloadArgDummy = std::make_unique<Argument>(ArgType);
+    return PreloadArgDummy.get();
+  }
+
+  LoadInst *createLoad(IRBuilder<NoFolder> &IRB, Value *Ptr,
+                       const StringRef &Name) const {
+    LoadInst *Load =
+        IRB.CreateAlignedLoad(ArgType, Ptr, ArgAlign, Name + ".val");
+    if (AAMD)
+      Load->setAAMetadata(AAMD);
+    return Load;
+  }
+
+  StoreInst *createStore(IRBuilder<NoFolder> &IRB, Value *V, Value *Ptr) const {
+    StoreInst *Store = IRB.CreateAlignedStore(V, Ptr, ArgAlign);
+    if (AAMD)
+      Store->setAAMetadata(AAMD);
+    return Store;
+  }
+
+  // Iterator to hide impl details on iterating promoted argument's users,
+  // espesially when GEPs added, by now - minimal trivial implementation.
+  class user_iterator
+      : public iterator_facade_base<user_iterator, std::forward_iterator_tag,
+                                    Value *> {
+    Argument::user_iterator ArgUserI;
+    friend struct ArgPromotionInfo;
+    user_iterator(const Argument::user_iterator &I) : ArgUserI(I) {}
+
+  public:
+    value_type operator*() const { return *ArgUserI; }
+    user_iterator &operator++() {
+      ++ArgUserI;
+      return *this;
+    }
+    user_iterator operator++(int) {
+      auto R = *this;
+      ++ArgUserI;
+      return R;
+    }
+    bool operator==(const user_iterator &RHS) const {
+      return ArgUserI == RHS.ArgUserI;
+    }
+  };
+  user_iterator user_begin() const { return user_iterator(Arg->user_begin()); }
+  user_iterator user_end() const { return user_iterator(Arg->user_end()); }
+  iterator_range<user_iterator> users() const {
+    return make_range(user_begin(), user_end());
+  }
+};
+
+// Return true if Pred is true for all callers passing P.Arg.
+static bool allCallersPass(
+    const ArgPromotionInfo &P,
+    function_ref<bool(CallBase *, Value *, const ArgPromotionInfo &)> Pred) {
+  Function *Callee = P.Arg->getParent();
+  for (User *U : Callee->users()) {
+    assert(isa<CallBase>(U));
+    CallBase *CB = cast<CallBase>(U);
+    if (!Pred(CB, CB->getArgOperand(P.getArgNo()), P))
+      return false;
+  }
+  return true;
+}
+
+// Given the function pointer argument that is only used by loads
+// return true if the value pointed by the argument can be loaded before the
+// function call and passed in:
+//   either the value is loaded by the ptr arg on every function path
+//   or the pointer is valid for all callsites in the program.
+static bool isROCandidate(ArgPromotionInfo &Candidate) {
+  SmallPtrSet<BasicBlock *, 16> ReadPerBB;
+  for (Value *U : Candidate.users()) {
+    assert(Candidate.isMyLoad(U));
+    ReadPerBB.insert(cast<Instruction>(U)->getParent());
+  }
+  bool HasLoadOnEveryPath = true;
+  Function *F = Candidate.Arg->getParent();
+  auto *EntryBB = &F->getEntryBlock();
+  for (auto DFI = df_begin(EntryBB), E = df_end(EntryBB); DFI != E;) {
+    BasicBlock *BB = *DFI;
+    if (ReadPerBB.count(BB)) {
+      DFI.skipChildren(); // This path already have load - skipping children.
+      continue;
+    }
+    if (isa<ReturnInst>(BB->getTerminator())) {
+      HasLoadOnEveryPath = false;
+      break;
+    }
+    ++DFI;
+  }
+
+  // Return true if we can prove that caller pass in a valid pointer.
+  const DataLayout &DL = F->getParent()->getDataLayout();
+  auto IsValidPtr = [&DL](Value *A, const ArgPromotionInfo &P) -> bool {
+    return isDereferenceableAndAlignedPointer(A, P.ArgType, P.ArgAlign, DL);
+  };
+
+  Candidate.Preload =
+      HasLoadOnEveryPath ||
+      // Check if the argument itself is marked dereferenceable and aligned,
+      IsValidPtr(Candidate.Arg, Candidate) ||
+      // or this is true for all the callers
+      allCallersPass(Candidate, [&IsValidPtr](CallBase *, Value *A,
+                                              const ArgPromotionInfo &P) {
+        return IsValidPtr(A, P);
+      });
+
+  LLVM_DEBUG(dbgs() << " - ";
+             if (HasLoadOnEveryPath) dbgs() << "has a load on every path,";
+             else dbgs()
+             << (Candidate.Preload ? "" : "not")
+             << " all callers pass a valid and aligned dereferenceable ptr,");
+
+  return Candidate.Preload;
+}
+
+// Given the function pointer argument that is only used by stores and maybe
+// loads return true if the value pointed by the argument can be stored after
+// and loaded before the function call and passed in/returned by the function:
+//   either the value is stored on every function path
+//   or the pointer points to a thread local memory that doesn't escape before
+//   the function call for every callsite in the program.
+// Check is made if a load precedes stores on any path so the initial value
+// should be passed in as a parameter.
+static bool isRWCandidate(FunctionAnalysisManager &FAM,
+                          ArgPromotionInfo &Candidate) {
+  SmallDenseMap<BasicBlock *, unsigned, 16> RWPerBB;
+  enum { HasReads = 1, HasWrites = 2 };
+  for (Value *U : Candidate.users()) {
+    assert(Candidate.isMyLoadOrStore(U));
+    RWPerBB[cast<Instruction>(U)->getParent()] |=
+        isa<LoadInst>(U) ? HasReads : HasWrites;
+  }
+  bool HasLoadBeforeStore = false;
+  bool HasStoreOnEveryPath = true;
+  Function *F = Candidate.Arg->getParent();
+  auto *EntryBB = &F->getEntryBlock();
+  for (auto DFI = df_begin(EntryBB), E = df_end(EntryBB); DFI != E;) {
+    BasicBlock *BB = *DFI;
+    auto RW = RWPerBB.find(BB);
+    if (RW != RWPerBB.end()) { // There is load or store within the BB.
+      if (!HasLoadBeforeStore && (RW->second & HasReads)) {
+        if (RW->second & HasWrites) {
+          // Determine if load locally dominates store.
+          auto LorS = find_if(*BB, [&Candidate](Instruction &I) -> bool {
+            return Candidate.isMyLoadOrStore(&I);
+          });
+          assert(LorS != BB->end());
+          HasLoadBeforeStore = isa<LoadInst>(*LorS);
+        } else
+          HasLoadBeforeStore = true;
+      }
+      if (RW->second & HasWrites) {
+        DFI.skipChildren(); // This path already have store - skipping children.
+        continue;
+      }
+    }
+    if (isa<ReturnInst>(BB->getTerminator()))
+      HasStoreOnEveryPath = false;
+
+    // Short-circuit: all the info is collected - nothing left to do.
+    if (HasLoadBeforeStore && !HasStoreOnEveryPath)
+      break;
+    ++DFI;
+  }
+
+  auto ValidThreadLocalPtr = [&FAM, F](CallBase *CallInst, Value *ActualPtr,
+                                       const ArgPromotionInfo &P) {
+    Value *Object = getUnderlyingObject(ActualPtr);
+    if (!isa<AllocaInst>(Object) &&
+        !isAllocLikeFn(Object, &FAM.getResult<TargetLibraryAnalysis>(*F)))
+      return false;
+
+    return !PointerMayBeCapturedBefore(
+        Object, /* ReturnCaptures */ false,
+        /* StoreCaptures */ true, CallInst,
+        &FAM.getResult<DominatorTreeAnalysis>(*F));
+  };
+
+  if (HasStoreOnEveryPath) {
+    Candidate.Preload = HasLoadBeforeStore;
+    Candidate.Return = true;
+    LLVM_DEBUG(dbgs() << " - has store on every path,");
+  } else {
+    // Preload the value so it can be returned unchanged on some path.
+    Candidate.Preload = Candidate.Return =
+        allCallersPass(Candidate, ValidThreadLocalPtr);
+    LLVM_DEBUG(dbgs() << " - " << (Candidate.Return ? "" : "not")
+                      << " all callers pass a valid thread local ptr,");
+  }
+  return Candidate.Return;
+}
+
+// Fill Candidates with the list of arguments potentially suitable for promotion
+static bool
+getPromotionCandidates(FunctionAnalysisManager &FAM, Argument *PtrArg,
+                       SmallVectorImpl<ArgPromotionInfo> &Candidates,
+                       bool InArgsOnly) {
+  LLVM_DEBUG(dbgs() << "  Trying arg: " << *PtrArg);
+
+  unsigned NumLoads = 0, NumStores = 0;
+  Type *ValueTy = nullptr;
+  Align ArgAlign; // Receives max alignment among the instructions.
+  for (auto *U : PtrArg->users()) {
+    Type *InstType = nullptr;
+    Align InstAlign;
+    if (auto *LI = dyn_cast<LoadInst>(U)) {
+      if (LI->isSimple()) {
+        InstType = LI->getType();
+        InstAlign = LI->getAlign();
+        ++NumLoads;
+      }
+    } else if (auto *SI = dyn_cast<StoreInst>(U)) {
+      if (SI->isSimple() && SI->getValueOperand() != PtrArg && !InArgsOnly) {
+        InstType = SI->getValueOperand()->getType();
+        InstAlign = SI->getAlign();
+        ++NumStores;
+      }
+    }
+    if (!InstType) {
+      LLVM_DEBUG(dbgs() << " - unsupported use " << *U << '\n');
+      return false;
+    }
+    if (!ValueTy) {
+      if (!InstType->isSingleValueType()) {
+        LLVM_DEBUG(dbgs() << " - unsupported type " << *InstType << '\n');
+        return false;
+      }
+      ValueTy = InstType;
+    } else if (ValueTy != InstType) {
+      LLVM_DEBUG(dbgs() << " - loads/stores don't agree on the type " << *U
+                        << '\n');
+      return false;
+    }
+    ArgAlign = std::max(ArgAlign, InstAlign);
+  }
+
+  Candidates.emplace_back(PtrArg, ValueTy, ArgAlign);
+  if (NumLoads + NumStores) {
+    auto &C = Candidates.back();
+    if (!(NumStores ? isRWCandidate(FAM, C) : isROCandidate(C))) {
+      Candidates.pop_back();
+      LLVM_DEBUG(dbgs() << " discard\n");
+      return false;
+    }
+    LLVM_DEBUG(dbgs() << " promote as " << C.getKindStr() << " arg\n");
+  } else {
+    // Otherwise - useless argument - to get rid off later.
+    LLVM_DEBUG(dbgs() << " - unused arg, remove\n");
+  }
+  return true;
+}
+
+class ArgumentPromoter {
+  Function *F;
+  FunctionAnalysisManager &FAM;
+  MemorySSA &MSSA;
+  unsigned NumMSSAWalksLeft;
+  SmallPtrSet<MemoryAccess *, 16> VisitedMA;
+
+  enum ClobberTestResult {
+    CheckOtherPhiPath,
+    ContinueThisPhiPath,
+    FoundClobber
+  };
+  using ClobberTestFx = enum ClobberTestResult(MemoryAccess *);
+
+  MemoryAccess *getClobber(MemoryAccess *MA, const MemoryLocation &Loc,
+                           function_ref<ClobberTestFx> ClobberTest,
+                           SmallPtrSetImpl<MemoryAccess *> &Visited);
+
+  MemoryAccess *getClobber(Instruction *I,
+                           function_ref<ClobberTestFx> ClobberTest,
+                           SmallPtrSetImpl<MemoryAccess *> &Visited);
+
+  MemoryAccess *getInOutArgClobber(const ArgPromotionInfo &ArgInfo);
+
+  using RetValuesMap =
+      SmallDenseMap<ReturnInst *, SmallVector<TrackingVH<Value>, 4>>;
+  void promoteInOutArg(ArgPromotionInfo &ArgInfo, RetValuesMap &RetValues);
+
+  Type *promoteInOutCandidates(
+      SmallVectorImpl<ArgPromotionInfo> &Candidates,
+      SmallVectorImpl<ArgPromotionInfo *> &RetValuesStoreOrder);
+
+  bool isInArgClobbered(const ArgPromotionInfo &ArgInfo);
+  void promoteInArg(ArgPromotionInfo &ArgInfo);
+
+  static Function *
+  createNewFunction(Function *OldF, Type *RetTy,
+                    const SmallVectorImpl<ArgPromotionInfo *> &PromotedArgs);
+
+  static void promoteCallsite(
+      CallBase &CB, Function *NF,
+      const SmallVectorImpl<ArgPromotionInfo *> &PromotedArgs,
+      const SmallVectorImpl<ArgPromotionInfo *> &RetValuesStoreOrder);
+
+public:
+  ArgumentPromoter(Function *F_, FunctionAnalysisManager &FAM_)
+      : F(F_), FAM(FAM_), MSSA(FAM.getResult<MemorySSAAnalysis>(*F).getMSSA()) {
+  }
+
+  Function *run(SmallVectorImpl<ArgPromotionInfo> &Candidates);
+};
+
+// Search memory access that clobbers Loc starting from MA. Does a BFS search
+// on phi paths. ClobberTest is run over every found clobber to negotiate it
+// further by the ClobberTest's return value:
+//   FoundClobber - stop search and return found clobber;
+//   ContinueThisPhiPath - skip found clobber and continue searching the path;
+//   CheckOtherPhiPath - skip found clobber and try other phi paths if any.
+// Return found clobber, LiveOnEntryDef if no clobber or nullptr if the maximum
+// number of uncached MSSA walks reached.
+MemoryAccess *
+ArgumentPromoter::getClobber(MemoryAccess *MA, const MemoryLocation &Loc,
+                             function_ref<ClobberTestFx> ClobberTest,
+                             SmallPtrSetImpl<MemoryAccess *> &Visited) {
+  std::deque<MemoryAccess *> FIFO;
+  do {
+    while (true) {
+      if (!Visited.insert(MA).second)
+        break;
+      if (MemoryPhi *Phi = dyn_cast<MemoryPhi>(MA)) {
+        for (auto *DefMA : make_range(Phi->defs_begin(), Phi->defs_end()))
+          FIFO.push_back(DefMA);
+        break;
+      }
+      if (--NumMSSAWalksLeft == 0) // Constrain the number of uncached walks.
+        return nullptr;
+      auto *ClobberMA = MSSA.getWalker()->getClobberingMemoryAccess(MA, Loc);
+      if (isa<MemoryPhi>(ClobberMA)) {
+        MA = ClobberMA;
+      } else if (!MSSA.isLiveOnEntryDef(ClobberMA)) {
+        ClobberTestResult R = ClobberTest(ClobberMA);
+        if (R == FoundClobber)
+          return ClobberMA;
+        else if (R == ContinueThisPhiPath)
+          MA = cast<MemoryUseOrDef>(ClobberMA)->getDefiningAccess();
+        else
+          break; // CheckOtherPhiPath
+      }
+    }
+    if (FIFO.empty())
+      break;
+    MA = FIFO.front();
+    FIFO.pop_front();
+  } while (true);
+  return MSSA.getLiveOnEntryDef();
+}
+
+// Similar the previous routine but searches memory access that clobbers
+// memory accessed by the I instruction.
+MemoryAccess *
+ArgumentPromoter::getClobber(Instruction *I,
+                             function_ref<ClobberTestFx> ClobberTest,
+                             SmallPtrSetImpl<MemoryAccess *> &Visited) {
+  assert(MemoryLocation::getOrNone(I).hasValue());
+  auto *ClobberMA = MSSA.getWalker()->getClobberingMemoryAccess(I);
+  if (MSSA.isLiveOnEntryDef(ClobberMA))
+    return ClobberMA;
+  if (isa<MemoryPhi>(ClobberMA))
+    return getClobber(ClobberMA, MemoryLocation::get(I), ClobberTest, Visited);
+
+  switch (ClobberTest(ClobberMA)) {
+  case FoundClobber:
+    return ClobberMA;
+  case CheckOtherPhiPath:
+    break; // No other path to test.
+  case ContinueThisPhiPath:
+    return getClobber(cast<MemoryUseOrDef>(ClobberMA)->getDefiningAccess(),
+                      MemoryLocation::get(I), ClobberTest, Visited);
+  }
+  return MSSA.getLiveOnEntryDef();
+}
+
+// TODO: move this to the MemorySSA class
+// Find last memory def or phi in the BB or in its dominating predecessors.
+// Note that a def in non-dominating predecessor would create phi in the BB.
+static MemoryAccess *getLastDef(BasicBlock *BB, MemorySSA &MSSA) {
+  if (auto *Defs = MSSA.getBlockDefs(BB))
+    return const_cast<MemoryAccess *>(&*Defs->rbegin());
+
+  DomTreeNode *Node = MSSA.getDomTree().getNode(BB);
+  while ((Node = Node->getIDom()))
+    if (auto *Defs = MSSA.getBlockDefs(Node->getBlock()))
+      return const_cast<MemoryAccess *>(&*Defs->rbegin());
+  return MSSA.getLiveOnEntryDef();
+}
+
+#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
+LLVM_DUMP_METHOD
+static void printClobber(raw_ostream &os, MemoryAccess *ClobberMA,
+                         Instruction *I) {
+  if (!ClobberMA) {
+    os << "clobber search reached limit\n";
+    return;
+  }
+  auto *ClobberI = cast<MemoryUseOrDef>(ClobberMA)->getMemoryInst();
+  os << "found clobber:" << *I << '@' << I->getParent()->getName()
+     << " is clobbered by" << *ClobberI << '@'
+     << ClobberI->getParent()->getName() << '\n';
+}
+#endif
+
+// Check if memops by the argument are clobbered by or clobber other memops.
+// Return found clobber, LiveOnEntryDef if no clobber or nullptr if the maximum
+// number of uncached MSSA walks reached.
+MemoryAccess *
+ArgumentPromoter::getInOutArgClobber(const ArgPromotionInfo &ArgInfo) {
+  LLVM_DEBUG(dbgs() << "  Searching for a clobber for " << ArgInfo.getKindStr()
+                    << " arg " << *ArgInfo.Arg << ": ");
+  auto SkipMyStore = [&ArgInfo](MemoryAccess *MA) -> ClobberTestResult {
+    return ArgInfo.isMyStore(cast<MemoryUseOrDef>(MA)->getMemoryInst())
+               ? CheckOtherPhiPath
+               : FoundClobber;
+  };
+  VisitedMA.clear(); // Using VisitedMA to track SkipMyStore condition tests.
+  // Check if a load by the argument is clobbered by something else than
+  // a store by the argument.
+  for (Value *U : ArgInfo.users()) {
+    assert(ArgInfo.isMyLoadOrStore(U));
+    if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
+      auto *Clob = getClobber(LI, SkipMyStore, VisitedMA);
+      if (!MSSA.isLiveOnEntryDef(Clob)) {
+        LLVM_DEBUG(printClobber(dbgs(), Clob, LI));
+        return Clob;
+      }
+    }
+  }
+  // Check if the argument has been clobbered between last store by the arg
+  // and return on any path.
+  MemoryLocation Loc(ArgInfo.getMemLoc());
+  for (auto &BB : *F) {
+    if (!isa<ReturnInst>(BB.getTerminator()))
+      continue;
+    auto *Clob = getClobber(getLastDef(&BB, MSSA), Loc, SkipMyStore, VisitedMA);
+    if (!MSSA.isLiveOnEntryDef(Clob)) {
+      LLVM_DEBUG(printClobber(dbgs(), Clob, BB.getTerminator()));
+      return Clob;
+    }
+  }
+  // Check if any other load is clobbered by a store by the argument.
+  AliasAnalysis &AA = FAM.getResult<AAManager>(*F);
+  for (auto &BB : *F) {
+    if (auto *L = MSSA.getBlockAccesses(&BB)) {
+      for (auto &MA : *L) {
+        if (auto *MU = dyn_cast<MemoryUse>(&MA)) {
+          Instruction *UseI = MU->getMemoryInst();
+          if (ArgInfo.isMyLoad(UseI))
+            continue;
+          auto UseLoc = MemoryLocation::getOrNone(UseI);
+          if (!UseLoc.hasValue()) {
+            LLVM_DEBUG(dbgs() << "cannot get memloc for " << *UseI << '\n');
+            // Conservatively consider this as a clobber.
+            return const_cast<MemoryUse *>(MU);
+          }
+          auto FindMyStore = [&](MemoryAccess *MA) -> ClobberTestResult {
+            Instruction *DefI = cast<MemoryUseOrDef>(MA)->getMemoryInst();
+            if (ArgInfo.isMyStore(DefI))
+              return FoundClobber;
+            // If the UseI's location is definitely overwritten with the clober
+            // we can skip this path, otherwise it can be clobbered earlier.
+            ModRefInfo MRI = AA.getModRefInfo(DefI, UseLoc);
+            return (isMustSet(MRI) && isModSet(MRI)) ? CheckOtherPhiPath
+                                                     : ContinueThisPhiPath;
+          };
+          VisitedMA.clear();
+          auto *Clob = getClobber(UseI, FindMyStore, VisitedMA);
+          if (!MSSA.isLiveOnEntryDef(Clob)) {
+            LLVM_DEBUG(printClobber(dbgs(), Clob, UseI));
+            return Clob;
+          }
+        }
+      }
+    }
+  }
+  LLVM_DEBUG(dbgs() << "no clobber\n");
+  return MSSA.getLiveOnEntryDef();
+}
+
+// Annotate each return with a value for the argument ArgInfo.
+// Create Phis and rewrites code.
+void ArgumentPromoter::promoteInOutArg(ArgPromotionInfo &ArgInfo,
+                                       RetValuesMap &RetValues) {
+  SmallDenseMap<BasicBlock *, SmallVector<Instruction *, 4>, 16> MemInsts;
+  SmallPtrSet<BasicBlock *, 4> DefBB;
+  for (Value *U : ArgInfo.users()) {
+    assert(ArgInfo.isMyLoadOrStore(U));
+
+    Instruction *I = cast<Instruction>(U);
+    if (MemInsts.empty())
+      ArgInfo.AAMD = I->getAAMetadata();
+    else if (ArgInfo.AAMD) // Merging AA metadata BTW.
+      ArgInfo.AAMD.merge(I->getAAMetadata());
+
+    BasicBlock *BB = I->getParent();
+    if (isa<StoreInst>(I))
+      DefBB.insert(BB);
+    MemInsts[BB].push_back(I);
+  }
+
+  SmallDenseMap<BasicBlock *, TrackingVH<Value>, 16> BBExitValue;
+
+  // Processing stores.
+  for (BasicBlock *BB : DefBB) {
+    auto &BBMemInsts = MemInsts[BB];
+    // Sort mem instructions in the program order.
+    sort(BBMemInsts, [this](Instruction *A, Instruction *B) {
+      return MSSA.locallyDominates(MSSA.getMemoryAccess(A),
+                                   MSSA.getMemoryAccess(B));
+    });
+    // Propagate store values down to the end of the basic block,
+    // loads preceding the first store will be processed later.
+    auto FirstStore =
+        find_if(BBMemInsts, [](Instruction *I) { return isa<StoreInst>(I); });
+    assert(FirstStore != BBMemInsts.end());
+    Value *V = nullptr;
+    for (Instruction *I : make_range(FirstStore, BBMemInsts.end())) {
+      if (isa<LoadInst>(I)) {
+        assert(V); // Since we started with a store.
+        I->replaceAllUsesWith(V);
+      } else
+        V = cast<StoreInst>(I)->getValueOperand();
+    }
+    assert(V);
+    BBExitValue[BB] = V;
+  }
+
+  SmallDenseMap<BasicBlock *, TrackingVH<Value>, 16> BBEntryValue;
+  auto setEntryValue = [&](BasicBlock *BB, Value *V) {
+    BBEntryValue[BB] = V;
+    // Keep BBExitValue left from store processing.
+    BBExitValue.try_emplace(BB, V);
+  };
+
+  if (ArgInfo.Preload)
+    setEntryValue(&F->getEntryBlock(), ArgInfo.getOrCreatePreloadArgDummy());
+
+  { // Inserting phis.
+    SmallVector<BasicBlock *, 16> PHIBlocks;
+    ForwardIDFCalculator IDF(MSSA.getDomTree());
+    IDF.setDefiningBlocks(DefBB);
+    IDF.calculate(PHIBlocks);
+
+    for (auto *JoinBB : PHIBlocks) {
+      auto P = MemInsts.find(JoinBB);
+      // If JoinBB starts with a store then phi value isn't used.
+      if (P == MemInsts.end() || isa<LoadInst>(P->second.front())) {
+        PHINode *Phi = PHINode::Create(ArgInfo.ArgType, 2,
+                                       ArgInfo.getParamName() +
+                                           dot(JoinBB->getName()) + ".phi",
+                                       &JoinBB->front());
+        setEntryValue(JoinBB, Phi);
+      }
+    }
+  }
+
+  auto findIncomingValue = [&](BasicBlock *BB) -> Value * {
+    DomTreeNode *Node = MSSA.getDomTree().getNode(BB);
+    while ((Node = Node->getIDom())) {
+      auto I = BBExitValue.find(Node->getBlock());
+      if (I != BBExitValue.end())
+        return I->second;
+    }
+    return UndefValue::get(ArgInfo.ArgType);
+  };
+
+  auto getBBExitValue = [&](BasicBlock *BB) -> Value * {
+    auto I = BBExitValue.find(BB);
+    if (I != BBExitValue.end())
+      return I->second;
+    return findIncomingValue(BB);
+  };
+
+  auto getBBEntryValue = [&](BasicBlock *BB) -> Value * {
+    auto I = BBEntryValue.find(BB);
+    if (I != BBEntryValue.end())
+      return I->second;
+    return findIncomingValue(BB);
+  };
+
+  // Processing phis.
+  const DataLayout &DL = F->getParent()->getDataLayout();
+  for (auto &P : BBEntryValue)
+    if (PHINode *Phi = dyn_cast<PHINode>(&*P.second)) {
+      for (BasicBlock *PredBB : predecessors(P.first))
+        Phi->addIncoming(getBBExitValue(PredBB), PredBB);
+
+      if (Value *V = SimplifyInstruction(Phi, DL)) {
+        Phi->replaceAllUsesWith(V);
+        Phi->eraseFromParent();
+      }
+    }
+
+  // Processing loads.
+  for (auto &P : MemInsts) {
+    auto &BBMemInsts = P.second;
+    if (!isa<LoadInst>(BBMemInsts.front()))
+      continue;
+    Value *V = getBBEntryValue(P.first);
+    auto I = BBMemInsts.begin(), E = BBMemInsts.end();
+    do {
+      (*I)->replaceAllUsesWith(V);
+    } while (++I != E && isa<LoadInst>(*I));
+  }
+
+  // Annotate returns.
+  for (BasicBlock &BB : *F)
+    if (auto *RetInst = dyn_cast<ReturnInst>(BB.getTerminator()))
+      RetValues[RetInst].push_back(getBBExitValue(&BB));
+
+  // Finally erase load/stores.
+  MemorySSAUpdater UMSSA(&MSSA);
+  for (Value *U : make_early_inc_range(ArgInfo.users())) {
+    assert(ArgInfo.isMyLoadOrStore(U));
+    UMSSA.removeMemoryAccess(cast<Instruction>(U));
+    cast<Instruction>(U)->eraseFromParent();
+  }
+#ifndef NDEBUG
+  MSSA.verifyMemorySSA();
+#endif
+}
+
+// Tries to promote [input/]output ptr arguments. It may happen that store
+// instructions for several arguments clobber one another, to solve this
+// an attempt to find an "unclobbering" promotion sequence is made.
+// For example:
+//     store PtrArgA(may alias), 1;
+//     store PtrArgB(may alias), 0; <- clobbers store PtrArgA
+//
+// First PtrArgB is promoted unclobbering PtrArgA which is promoted second.
+// Notice that it is only possible if such stores obey the same order in every
+// basic block, otherwise we cannot unclobber these at all. Promoted stores are
+// then placed in the caller in the same order making the transformation safe.
+//
+// This could be left for the following passes but it's better to perform such
+// unclobbering all at once not only because of compilation speed but it also
+// allows to simplify the return value of the function: otherwise we would have
+// to deal with an onion-like aggregated return type with a bulky INSERT_VALUE/
+// EXTRACT_VALUE sequence.
+Type *ArgumentPromoter::promoteInOutCandidates(
+    SmallVectorImpl<ArgPromotionInfo> &Candidates,
+    SmallVectorImpl<ArgPromotionInfo *> &RetValuesStoreOrder) {
+
+  // Priority queue is ordered so that clobbered candidates pop last.
+  struct ClobberedPopLast {
+    // Returns true if its first argument comes before its second argument in a
+    // weak ordering. But because the priority queue outputs largest elements
+    // first, the elements that "come before" are actually output last.
+    bool operator()(const ArgPromotionInfo *A1,
+                    const ArgPromotionInfo *A2) const {
+      assert(!A1->isClobberedBy(*A2) || !A2->isClobberedBy(*A1));
+      return A1->isClobberedBy(*A2);
+    }
+  };
+  struct CandidateQueue
+      : std::priority_queue<ArgPromotionInfo *,
+                            SmallVector<ArgPromotionInfo *, 4>,
+                            ClobberedPopLast> {
+    CandidateQueue(SmallVectorImpl<ArgPromotionInfo> &Candidates) {
+      // This might seem as a dirty hack but until ClobberedBy is set no order
+      // on candidates can be established, so just store them as is
+      for (auto &C : Candidates) {
+        if (C.Return) {
+          assert(!C.ClobberedBy); // but let's be carefull.
+          c.push_back(&C);
+        }
+      }
+    }
+    // This is placed here because priority_queue container is protected.
+    ArgPromotionInfo *findClobber(StoreInst *SI) const {
+      auto Clobber =
+          std::find_if(c.begin(), c.end(), [SI](const ArgPromotionInfo *A) {
+            return A->isMyStore(SI);
+          });
+      return Clobber != c.end() ? *Clobber : nullptr;
+    }
+  } Queue(Candidates);
+
+  RetValuesMap RetValues;
+  unsigned NumPromoted = 0;
+  while (!Queue.empty()) {
+    ArgPromotionInfo &C = *Queue.top();
+    Queue.pop();
+    if (C.ClobberedBy && !C.ClobberedBy->isPromoted()) // [1]
+      continue;                                        // the clobber isn't gone
+    MemoryAccess *ClobberMA = getInOutArgClobber(C);
+    if (MSSA.isLiveOnEntryDef(ClobberMA)) {
+      promoteInOutArg(C, RetValues);
+      // ReturnValueIndex is used as the index of the arg's value in the map
+      // up until this function's exit, see below.
+      C.ReturnValueIndex = NumPromoted++;
+      continue;
+    }
+    MemoryDef *MDef = dyn_cast_or_null<MemoryDef>(ClobberMA);
+    if (!MDef)
+      continue;
+    // If the clobbering store belongs to another candidate in the queue
+    // enqueue the current candidate back with the ClobberedBy set so we can
+    // retry it after the clobbering candidate has been promoted.
+    StoreInst *SI = dyn_cast<StoreInst>(MDef->getMemoryInst());
+    if (!SI || !SI->isSimple() || C.isMyStore(SI))
+      continue;
+    if (ArgPromotionInfo *Clobber = Queue.findClobber(SI)) {
+      C.ClobberedBy = Clobber;
+      if (!Clobber->isClobberedBy(C))
+        Queue.push(&C);
+      // Otherwise this is a circular dependency, other candidates will be
+      // removed by the condition [1].
+    }
+  }
+
+  Type *OldRetTy = F->getReturnType();
+  if (!NumPromoted)
+    return OldRetTy;
+
+  SmallVector<Type *, 5> ReturnArgTypes;
+  ReturnArgTypes.reserve(NumPromoted + 1);
+  if (!OldRetTy->isVoidTy())
+    ReturnArgTypes.push_back(OldRetTy);
+
+  SmallVector<ArgPromotionInfo *, 4> ReturnArgs;
+  ReturnArgs.reserve(NumPromoted);
+  for (ArgPromotionInfo &C : Candidates) {
+    if (C.isPromoted()) {
+      assert(C.Return);
+      ReturnArgs.push_back(&C);
+      ReturnArgTypes.push_back(C.ArgType);
+    }
+  }
+
+  Type *RetTy = ReturnArgTypes.size() > 1
+                    ? StructType::get(F->getContext(), ReturnArgTypes)
+                    : ReturnArgTypes.front();
+
+  // Replace old return instructions using annotated return values.
+  for (auto &P : RetValues) {
+    ReturnInst *OldRetInst = P.first;
+    const auto &Values = P.second;
+    assert(Values.size() == NumPromoted);
+    Value *RetValue;
+    if (OldRetTy->isVoidTy() && NumPromoted == 1)
+      RetValue = Values[0];
+    else {
+      SmallString<256> NameData;
+      StringRef Name =
+          (F->getName() + dot(OldRetInst->getParent()->getName()) + ".ret")
+              .toStringRef(NameData);
+      RetValue = UndefValue::get(RetTy);
+      unsigned I = 0;
+      if (!OldRetTy->isVoidTy()) {
+        RetValue = InsertValueInst::Create(
+            RetValue, OldRetInst->getReturnValue(), {I++}, Name, OldRetInst);
+      }
+      for (const ArgPromotionInfo *C : ReturnArgs) {
+        RetValue =
+            InsertValueInst::Create(RetValue, Values[C->ReturnValueIndex], {I},
+                                    Name + Twine(I), OldRetInst);
+        ++I;
+      }
+    }
+    ReturnInst::Create(OldRetInst->getContext(), RetValue, OldRetInst);
+    OldRetInst->eraseFromParent();
+  }
+
+  RetValuesStoreOrder.resize(NumPromoted);
+  for (unsigned I = 0; I < NumPromoted; I++) {
+    ArgPromotionInfo *C = ReturnArgs[I];
+    RetValuesStoreOrder[NumPromoted - 1 - C->ReturnValueIndex] = C;
+    // ReturnValueIndex is now the index in the aggregated return type.
+    C->ReturnValueIndex = I + (OldRetTy->isVoidTy() ? 0 : 1);
+  }
+  return RetTy;
+}
+
+bool ArgumentPromoter::isInArgClobbered(const ArgPromotionInfo &ArgInfo) {
+  LLVM_DEBUG(dbgs() << "  Searching for a clobber for in arg " << *ArgInfo.Arg
+                    << ": ");
+  assert(!ArgInfo.Return && ArgInfo.Preload);
+  auto *Walker = MSSA.getWalker();
+  for (Value *U : ArgInfo.users()) {
+    assert(ArgInfo.isMyLoad(U));
+    LoadInst *LI = cast<LoadInst>(U);
+    auto *ClobberMA = Walker->getClobberingMemoryAccess(LI);
+    if (!MSSA.isLiveOnEntryDef(ClobberMA)) {
+      LLVM_DEBUG(printClobber(dbgs(), ClobberMA, LI));
+      return true;
+    }
+  }
+  LLVM_DEBUG(dbgs() << "no clobber\n");
+  return false;
+}
+
+void ArgumentPromoter::promoteInArg(ArgPromotionInfo &ArgInfo) {
+  assert(!ArgInfo.Return && ArgInfo.Preload);
+  MemorySSAUpdater UMSSA(&MSSA);
+  bool FirstAAMD = true;
+  for (Value *U : make_early_inc_range(ArgInfo.users())) {
+    assert(ArgInfo.isMyLoad(U));
+    LoadInst *LI = cast<LoadInst>(U);
+    if (FirstAAMD) {
+      ArgInfo.AAMD = LI->getAAMetadata();
+      FirstAAMD = false;
+    } else if (ArgInfo.AAMD)
+      ArgInfo.AAMD.merge(LI->getAAMetadata());
+    LI->replaceAllUsesWith(ArgInfo.getOrCreatePreloadArgDummy());
+    UMSSA.removeMemoryAccess(LI);
+    LI->eraseFromParent();
+  }
+#ifndef NDEBUG
+  MSSA.verifyMemorySSA();
+#endif
+}
+
+// Create the function with the new signature.
+Function *ArgumentPromoter::createNewFunction(
+    Function *OldF, Type *RetTy,
+    const SmallVectorImpl<ArgPromotionInfo *> &PromotedArgs) {
+
+  SmallVector<Type *, 8> Params;
+  SmallVector<AttributeSet, 8> ParamAttr;
+  AttributeList PAL = OldF->getAttributes();
+  auto PA = PromotedArgs.begin();
+  for (unsigned ArgNo = 0; ArgNo < OldF->arg_size(); ++ArgNo) {
+    if (PA != PromotedArgs.end() && (*PA)->getArgNo() == ArgNo) {
+      assert((*PA)->isPromoted() || (*PA)->isUnusedArg());
+      if ((*PA)->PreloadArgDummy) {
+        Params.push_back((*PA)->ArgType);
+        ParamAttr.push_back(AttributeSet());
+      }
+      ++PA;
+    } else {
+      Params.push_back(OldF->getArg(ArgNo)->getType());
+      ParamAttr.push_back(PAL.getParamAttrs(ArgNo));
+    }
+  }
+  assert(PA == PromotedArgs.end());
+
+  FunctionType *OldFTy = OldF->getFunctionType();
+  FunctionType *NFTy = FunctionType::get(RetTy, Params, OldFTy->isVarArg());
+  Function *NF = Function::Create(NFTy, OldF->getLinkage(),
+                                  OldF->getAddressSpace(), OldF->getName());
+  NF->copyAttributesFrom(OldF);
+  NF->copyMetadata(OldF, 0);
+  NF->setAttributes(AttributeList::get(OldF->getContext(), PAL.getFnAttrs(),
+                                       PAL.getRetAttrs(), ParamAttr));
+
+  // The new function will have the !dbg metadata copied from the original
+  // function. The original function may not be deleted, and dbg metadata need
+  // to be unique so we need to drop it.
+  OldF->setSubprogram(nullptr);
+  OldF->getParent()->getFunctionList().insert(OldF->getIterator(), NF);
+  NF->takeName(OldF);
+  NF->getBasicBlockList().splice(NF->begin(), OldF->getBasicBlockList());
+
+  auto NewArgI = NF->arg_begin();
+  PA = PromotedArgs.begin();
+  for (unsigned ArgNo = 0; ArgNo < OldF->arg_size(); ++ArgNo) {
+    Argument &OldArg = *OldF->getArg(ArgNo);
+    if (PA != PromotedArgs.end() && (*PA)->getArgNo() == ArgNo) {
+      assert((*PA)->isPromoted() || (*PA)->isUnusedArg());
+      if ((*PA)->PreloadArgDummy) {
+        (*PA)->PreloadArgDummy->replaceAllUsesWith(NewArgI);
+        NewArgI->setName((*PA)->getParamName());
+        // Replace potential metadata uses (like llvm.dbg.value) with undef.
+        OldArg.replaceAllUsesWith(UndefValue::get(OldArg.getType()));
+        ++NewArgI;
+      }
+      ++PA;
+    } else {
+      OldArg.replaceAllUsesWith(&*NewArgI);
+      NewArgI->takeName(&OldArg);
+      ++NewArgI;
+    }
+  }
+  assert(PA == PromotedArgs.end());
+  return NF;
+}
+
+// Promote callsite to call the new function signature inserting loads and
+// stores before and after the callsite.
+void ArgumentPromoter::promoteCallsite(
+    CallBase &CB, Function *NF,
+    const SmallVectorImpl<ArgPromotionInfo *> &PromotedArgs,
+    const SmallVectorImpl<ArgPromotionInfo *> &RetValuesStoreOrder) {
+
+  SmallVector<Value *, 16> Args;
+  SmallVector<AttributeSet, 8> ArgsAttr;
+  const AttributeList &CallPAL = CB.getAttributes();
+  IRBuilder<NoFolder> IRB(&CB);
+  auto PA = PromotedArgs.begin();
+  for (unsigned ArgNo = 0; ArgNo < CB.arg_size(); ++ArgNo) {
+    Value *CallOp = CB.getArgOperand(ArgNo);
+    if (PA != PromotedArgs.end() && (*PA)->getArgNo() == ArgNo) {
+      assert((*PA)->isPromoted() || (*PA)->isUnusedArg());
+      if ((*PA)->PreloadArgDummy) {
+        Args.push_back((*PA)->createLoad(IRB, CallOp, CallOp->getName()));
+        ArgsAttr.push_back(AttributeSet());
+      }
+      ++PA;
+    } else {
+      Args.push_back(CallOp);
+      ArgsAttr.push_back(CallPAL.getParamAttrs(ArgNo));
+    }
+  }
+  assert(PA == PromotedArgs.end());
+
+  SmallVector<OperandBundleDef, 1> OpBundles;
+  CB.getOperandBundlesAsDefs(OpBundles);
+  CallBase *NewCS = nullptr;
+  if (InvokeInst *II = dyn_cast<InvokeInst>(&CB)) {
+    NewCS = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
+                               Args, OpBundles, "", &CB);
+  } else {
+    auto *NewCall = CallInst::Create(NF, Args, OpBundles, "", &CB);
+    NewCall->setTailCallKind(cast<CallInst>(&CB)->getTailCallKind());
+    NewCS = NewCall;
+  }
+  NewCS->setCallingConv(CB.getCallingConv());
+  NewCS->copyMetadata(CB, {LLVMContext::MD_prof, LLVMContext::MD_dbg});
+  NewCS->takeName(&CB);
+  NewCS->setAttributes(AttributeList::get(
+      NF->getContext(), CallPAL.getFnAttrs(), CallPAL.getRetAttrs(), ArgsAttr));
+
+  if (RetValuesStoreOrder.empty()) {
+    CB.replaceAllUsesWith(NewCS);
+    return;
+  }
+
+  // Processing return values.
+  bool OldRetTyIsVoid = CB.getCalledFunction()->getReturnType()->isVoidTy();
+  if (OldRetTyIsVoid && RetValuesStoreOrder.size() == 1) {
+    const ArgPromotionInfo *A = RetValuesStoreOrder.front();
+    A->createStore(IRB, NewCS, CB.getArgOperand(A->getArgNo()));
+  } else {
+    if (!OldRetTyIsVoid && !CB.user_empty())
+      CB.replaceAllUsesWith(
+          IRB.CreateExtractValue(NewCS, {0}, NewCS->getName() + ".ret"));
+    for (const ArgPromotionInfo *A : RetValuesStoreOrder) {
+      Value *CallOp = CB.getArgOperand(A->getArgNo());
+      Value *RetVal = IRB.CreateExtractValue(NewCS, {A->ReturnValueIndex},
+                                             CallOp->getName() + ".val.ret");
+      A->createStore(IRB, RetVal, CallOp);
+    }
+  }
+}
+
+// Try to promote function argument candidates and update callsites.
+Function *ArgumentPromoter::run(SmallVectorImpl<ArgPromotionInfo> &Candidates) {
+  // Reload MSSA uncached walks constraint.
+  NumMSSAWalksLeft = MaxMSSAWalksNum * Candidates.size();
+
+  SmallVector<ArgPromotionInfo *, 4> RetValuesStoreOrder;
+  Type *RetType = promoteInOutCandidates(Candidates, RetValuesStoreOrder);
+
+  SmallVector<ArgPromotionInfo *, 4> PromotedArgs;
+  for (ArgPromotionInfo &C : Candidates) {
+    if (C.Return) {
+      ++NumInOutArgCandidates;
+      if (C.isPromoted()) {
+        PromotedArgs.push_back(&C);
+        ++NumInOutArgPromoted;
+      }
+    } else if (C.Preload) {
+      ++NumInArgCandidates;
+      if (!isInArgClobbered(C)) {
+        promoteInArg(C);
+        PromotedArgs.push_back(&C);
+        ++NumInArgPromoted;
+      }
+    } else {
+      assert(C.isUnusedArg());
+      PromotedArgs.push_back(&C); // Will be removed from the func signature.
+    }
+  }
+
+  if (PromotedArgs.empty())
+    return nullptr;
+
+  Function *NF = createNewFunction(F, RetType, PromotedArgs);
+
+  // Update callsites.
+  for (auto *U : make_early_inc_range(F->users())) {
+    assert(isa<CallBase>(U));
+    CallBase &CB = *cast<CallBase>(U);
+    assert(CB.getCalledFunction() == F && CB.getParent()->getParent() != F);
+    promoteCallsite(CB, NF, PromotedArgs, RetValuesStoreOrder);
+    CB.eraseFromParent();
+  }
+  return NF;
+}
+
+// This method checks the specified function to see if there're any
+// promotable arguments and if it is safe to promote the function (for
+// example, all callers are direct) and performs the promotion.
+static Function *promoteArguments(Function *F, FunctionAnalysisManager &FAM) {
+  // Don't perform argument promotion for naked functions; otherwise we can end
+  // up removing parameters that are seemingly 'not used' as they are referred
+  // to in the assembly.
+  if (F->hasFnAttribute(Attribute::Naked))
+    return nullptr;
+
+  // Make sure that it is local to this module.
+  if (!F->hasLocalLinkage())
+    return nullptr;
+
+  // Don't promote arguments for variadic functions. Adding, removing, or
+  // changing non-pack parameters can change the classification of pack
+  // parameters. Frontends encode that classification at the call site in the
+  // IR, while in the callee the classification is determined dynamically based
+  // on the number of registers consumed so far.
+  if (F->isVarArg())
+    return nullptr;
+
+  // Don't transform functions that receive inallocas, as the transformation may
+  // not be safe depending on calling convention.
+  if (F->getAttributes().hasAttrSomewhere(Attribute::InAlloca))
+    return nullptr;
+
+  // See if there are any pointer arguments.
+  if (F->args().end() == find_if(F->args(), [](Argument &A) {
+        return A.getType()->isPointerTy();
+      }))
+    return nullptr;
+
+  LLVM_DEBUG(dbgs() << "Trying to promote arguments for " << F->getName()
+                    << '\n');
+
+  // If the function has attributes for the return value they most likely
+  // would not make sense for the aggregated return value, so we discard any
+  // in/out arguments. The same applies to the return attributes at callsites.
+  bool InArgsOnly = F->getAttributes().getRetAttrs().hasAttributes();
+
+  for (Use &U : F->uses()) {
+    CallBase *CB = dyn_cast<CallBase>(U.getUser());
+    // Must be a direct call.
+    if (CB == nullptr || !CB->isCallee(&U)) // [1]
+      return nullptr;
+
+    // Can't change signature of musttail callee
+    if (CB->isMustTailCall())
+      return nullptr;
+
+    if (!InArgsOnly && CB->getAttributes().getRetAttrs().hasAttributes())
+      InArgsOnly = true;
+  }
+
+  // Can't change signature of musttail caller
+  for (BasicBlock &BB : *F)
+    if (BB.getTerminatingMustTailCall())
+      return nullptr;
+
+  SmallVector<ArgPromotionInfo, 4> Candidates;
+  for (Argument &A : F->args())
+    if (A.getType()->isPointerTy())
+      getPromotionCandidates(FAM, &A, Candidates, InArgsOnly);
+
+  if (Candidates.empty())
+    return nullptr;
+
+  { // Make sure preloaded arguments are ABI compatible.
+    // TODO: Check individual arguments so we can promote a subset?
+    SmallVector<Type *, 32> Types;
+    for (auto &C : Candidates) {
+      if (C.Preload)
+        Types.push_back(C.ArgType);
+    }
+    if (!Types.empty()) {
+      const TargetTransformInfo &TTI = FAM.getResult<TargetIRAnalysis>(*F);
+      for (const Use &U : F->uses()) {
+        CallBase *CB = cast<CallBase>(U.getUser()); // due to check [1]
+        if (!TTI.areTypesABICompatible(CB->getCaller(), F, Types))
+          return nullptr;
+      }
+    }
+  }
+
+  return ArgumentPromoter(F, FAM).run(Candidates);
+}
+
+PreservedAnalyses MSSAArgPromotionPass::run(LazyCallGraph::SCC &C,
+                                            CGSCCAnalysisManager &AM,
+                                            LazyCallGraph &CG,
+                                            CGSCCUpdateResult &UR) {
+  bool Changed = false, LocalChange;
+  do { // Iterate until we stop promoting from this SCC.
+    LocalChange = false;
+    for (LazyCallGraph::Node &N : C) {
+      Function &OldF = N.getFunction();
+      FunctionAnalysisManager &FAM =
+          AM.getResult<FunctionAnalysisManagerCGSCCProxy>(C, CG).getManager();
+      if (Function *NewF = promoteArguments(&OldF, FAM)) {
+        // Directly substitute the functions in the call graph. Note that this
+        // requires the old function to be completely dead and completely
+        // replaced by the new function. It does no call graph updates, it
+        // merely swaps out the particular function mapped to a particular node
+        // in the graph.
+        C.getOuterRefSCC().replaceNodeFunction(N, *NewF);
+        FAM.clear(OldF, OldF.getName());
+        OldF.eraseFromParent();
+        LocalChange = true;
+      }
+    }
+    Changed |= LocalChange;
+  } while (LocalChange);
+
+  if (!Changed)
+    return PreservedAnalyses::all();
+
+  return PreservedAnalyses::none(); // Since the function signature is changed.
+}
+
+namespace {
+struct MSSAArgPromotion : public CallGraphSCCPass {
+  static char ID;
+
+  FunctionAnalysisManager FAM;
+
+  explicit MSSAArgPromotion() : CallGraphSCCPass(ID) {
+    initializeMSSAArgPromotionPass(*PassRegistry::getPassRegistry());
+    FAM.registerPass([&] { return PassInstrumentationAnalysis(); });
+    FAM.registerPass([&] { return TargetIRAnalysis(); });
+    FAM.registerPass([&] { return TargetLibraryAnalysis(); });
+    FAM.registerPass([&] { return AAManager(); });
+    FAM.registerPass([&] { return DominatorTreeAnalysis(); });
+    FAM.registerPass([&] { return MemorySSAAnalysis(); });
+  }
+
+  void getAnalysisUsage(AnalysisUsage &AU) const override {
+    CallGraphSCCPass::getAnalysisUsage(AU);
+  }
+
+  bool runOnSCC(CallGraphSCC &SCC) override;
+};
+} // end anonymous namespace
+
+char MSSAArgPromotion::ID = 0;
+
+INITIALIZE_PASS_BEGIN(MSSAArgPromotion, "mssaargpromotion",
+                      "MSSA Promote 'by reference' arguments to scalars", false,
+                      false)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
+INITIALIZE_PASS_END(MSSAArgPromotion, "mssaargpromotion",
+                    "MSSA Promote 'by reference' arguments to scalars", false,
+                    false)
+
+Pass *llvm::createMSSAArgPromotionPass() { return new MSSAArgPromotion(); }
+
+bool MSSAArgPromotion::runOnSCC(CallGraphSCC &SCC) {
+  if (skipSCC(SCC))
+    return false;
+
+  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+  bool Changed = false, LocalChange;
+  do {
+    LocalChange = false;
+    for (CallGraphNode *OldNode : SCC) {
+      Function *OldF = OldNode->getFunction();
+      if (!OldF)
+        continue;
+
+      // Clear FAM but preserve immutable results.
+      FAM.invalidate(*OldF, PreservedAnalyses::none());
+
+      if (Function *NewF = promoteArguments(OldF, FAM)) {
+        LocalChange = true;
+
+        // Update the call graph for the newly promoted function.
+        CallGraphNode *NewNode = CG.getOrInsertFunction(NewF);
+        NewNode->stealCalledFunctionsFrom(OldNode);
+
+        // Update call edges
+        SmallDenseSet<CallGraphNode *> ClearedNodes;
+        for (auto *U : make_early_inc_range(NewF->users())) {
+          assert(isa<CallBase>(U));
+          CallBase &CB = *cast<CallBase>(U);
+          CallGraphNode *CallerNode = CG[CB.getParent()->getParent()];
+          if (ClearedNodes.insert(CallerNode).second)
+            CallerNode->removeAnyCallEdgeTo(OldNode);
+          CallerNode->addCalledFunction(&CB, NewNode);
+        }
+        assert(OldNode->getNumReferences() == 0);
+        delete CG.removeFunctionFromModule(OldNode);
+        SCC.ReplaceNode(OldNode, NewNode);
+      }
+    }
+    Changed |= LocalChange;
+  } while (LocalChange);
+  return Changed;
+}
diff --git a/llvm/test/CodeGen/AMDGPU/opt-pipeline.ll b/llvm/test/CodeGen/AMDGPU/opt-pipeline.ll
--- a/llvm/test/CodeGen/AMDGPU/opt-pipeline.ll
+++ b/llvm/test/CodeGen/AMDGPU/opt-pipeline.ll
@@ -770,6 +770,7 @@
 ; GCN-O3-NEXT:       OpenMP specific optimizations
 ; GCN-O3-NEXT:       Deduce function attributes
 ; GCN-O3-NEXT:       Promote 'by reference' arguments to scalars
+; GCN-O3-NEXT:       MSSA Promote 'by reference' arguments to scalars
 ; GCN-O3-NEXT:       FunctionPass Manager
 ; GCN-O3-NEXT:         Dominator Tree Construction
 ; GCN-O3-NEXT:         Basic Alias Analysis (stateless AA impl)
diff --git a/llvm/test/Transforms/ArgumentPromotion/align.ll b/llvm/test/Transforms/ArgumentPromotion/align.ll
--- a/llvm/test/Transforms/ArgumentPromotion/align.ll
+++ b/llvm/test/Transforms/ArgumentPromotion/align.ll
@@ -1,5 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt -S -argpromotion < %s | FileCheck %s
+; RUN: opt -S -mssaargpromotion < %s | FileCheck %s
 
 define internal i32 @callee_must_exec(i32* %p) {
 ; CHECK-LABEL: define {{[^@]+}}@callee_must_exec
diff --git a/llvm/test/Transforms/ArgumentPromotion/inoutargs.ll b/llvm/test/Transforms/ArgumentPromotion/inoutargs.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Transforms/ArgumentPromotion/inoutargs.ll
@@ -0,0 +1,1103 @@
+; RUN: opt < %s -passes=mssaargpromotion -S | FileCheck %s
+
+;------- chain of calls
+; CHECK-LABEL: define internal i32 @inner_fx(i32 %P.0.val) {
+; CHECK-NEXT:   %V = add i32 %P.0.val, 1
+; CHECK-NEXT:   ret i32 %V
+define internal void @inner_fx(i32* %P) {
+  %L = load i32, i32* %P;
+  %V = add i32 %L, 1;
+  store i32 %V, i32* %P
+  ret void
+}
+
+; CHECK-LABEL: define internal i32 @outer_fx(i32 %P.0.val) {
+; CHECK-NEXT:   %V1 = add i32 %P.0.val, 2
+; CHECK-NEXT:   %1 = call i32 @inner_fx(i32 %V1)
+; CHECK-NEXT:   %V2 = add i32 %1, 3
+; CHECK-NEXT:   ret i32 %V2
+define internal void @outer_fx(i32* %P) {
+  %L1 = load i32, i32* %P;
+  %V1 = add i32 %L1, 2;
+  store i32 %V1, i32* %P
+  call void @inner_fx(i32* %P)
+  %L2 = load i32, i32* %P;
+  %V2 = add i32 %L2, 3;
+  store i32 %V2, i32* %P
+  ret void
+}
+
+; CHECK-LABEL: define void @test_chain_of_calls(i32* %P) {
+; CHECK-NEXT:   %P.val = load i32, i32* %P, align 4
+; CHECK-NEXT:   %1 = call i32 @outer_fx(i32 %P.val)
+; CHECK-NEXT:   store i32 %1, i32* %P, align 4
+define void @test_chain_of_calls(i32* %P) {
+  call void @outer_fx(i32* %P)
+  ret void
+}
+
+
+;-------
+;CHECK-LABEL: define internal { i32, i32 } @test_not_all_path_store(i1 %c, i32 %P.0.val) {
+;CHECK-NEXT:  br i1 %c, label %exit1, label %exit2
+;CHECK-LABEL: exit1:
+;CHECK-NEXT:   %test_not_all_path_store.exit1.ret = insertvalue { i32, i32 } undef, i32 1, 0
+;CHECK-NEXT:   %test_not_all_path_store.exit1.ret1 = insertvalue { i32, i32 } %test_not_all_path_store.exit1.ret, i32 42, 1
+;CHECK-NEXT:   ret { i32, i32 } %test_not_all_path_store.exit1.ret1
+;CHECK-LABEL: exit2:
+;CHECK-NEXT:   %test_not_all_path_store.exit2.ret = insertvalue { i32, i32 } undef, i32 2, 0
+;CHECK-NEXT:   %test_not_all_path_store.exit2.ret1 = insertvalue { i32, i32 } %test_not_all_path_store.exit2.ret, i32 %P.0.val, 1
+;CHECK-NEXT:   ret { i32, i32 } %test_not_all_path_store.exit2.ret1
+define internal i32 @test_not_all_path_store(i1 %c, i32* %P) {
+  br i1 %c, label %exit1, label %exit2
+
+exit1:
+  store i32 42, i32* %P
+  ret i32 1
+
+exit2:
+  ret i32 2
+}
+
+;CHECK-LABEL: define i32 @test_not_all_path_store_caller(i1 %c) {
+;CHECK-NEXT:  %M = alloca i32, align 4
+;CHECK-NEXT:  %M.val = load i32, i32* %M, align 4
+;CHECK-NEXT:  %R = call { i32, i32 } @test_not_all_path_store(i1 %c, i32 %M.val)
+;CHECK-NEXT:  %R.ret = extractvalue { i32, i32 } %R, 0
+;CHECK-NEXT:  %M.val.ret = extractvalue { i32, i32 } %R, 1
+;CHECK-NEXT:  store i32 %M.val.ret, i32* %M, align 4
+;CHECK-NEXT:  %V = load i32, i32* %M, align 4
+;CHECK-NEXT:  %Sum = add i32 %R.ret, %V
+;CHECK-NEXT:  ret i32 %Sum
+define i32 @test_not_all_path_store_caller(i1 %c) {
+  %M = alloca i32;
+  %R = call i32 @test_not_all_path_store(i1 %c, i32* %M)
+  %V = load i32, i32* %M
+  %Sum = add i32 %R, %V
+  ret i32 %Sum
+}
+
+;-------  test that clobber of L2 load by P1 store is detected
+;CHECK-LABEL: define internal void @test_getInOutArgClobber_visited
+define internal void @test_getInOutArgClobber_visited(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  br i1 %c, label %left, label %right
+
+;CHECK-LABEL: left:
+;CHECK-NEXT: store
+left:
+  store i32 1, i32* %P1 ; clobbers L2 load
+  br i1 %c, label %exit1, label %exit2
+
+right:
+  br i1 %c, label %exit1, label %exit2
+
+exit1:
+  %L1 = load i32, i32* %P1
+  ret void
+
+exit2:
+  %L2 = load i32, i32* %P2
+  ret void
+}
+
+define void @test_getInOutArgClobber_visited_caller(i1 %c, i32* %P2) {
+  %M = alloca i32
+  call void @test_getInOutArgClobber_visited(i1 %c, i32* %M, i32* %P2);
+  ret void
+}
+
+;------- check store clobbering other loads
+
+;CHECK-LABEL: define internal void @test_store_clobber1
+define internal void @test_store_clobber1(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+;CHECK: store i32 42, i32* %P1
+;CHECK: store i32 1, i32* %P3
+;CHECK: %V2 = load i32, i32* %P2
+  store i32 42, i32* %P1 ; this store clobbers V2 load (e.g. P1 == P2 != P3)
+  store i32 1, i32* %P3
+  %V2 = load i32, i32* %P2
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P3 store
+  ret void
+}
+
+define void @test_store_clobber1_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_clobber1(i32* %P1, i32* %P2, i32* %P3)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_store_no_clobber1
+define internal void @test_store_no_clobber1(i32* %P1, i32* %P2) { ; P1 may alias P2
+  store i32 42, i32* %P1
+  store i32 1, i32* %P2
+  %V2 = load i32, i32* %P2
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_no_clobber1_caller
+define void @test_store_no_clobber1_caller(i32* %P1, i32* %P2) {
+  call void @test_store_no_clobber1(i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_store_no_clobber1
+; store P2 and then P1 to preserve order in @test_store_no_clobber1
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_store_diamond_clobber1
+define internal void @test_store_diamond_clobber1(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  br i1 %c, label %st1, label %st2
+;CHECK-LABEL: st1:
+;CHECK-NEXT: br
+st1:
+  store i32 42, i32* %P1
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  store i32 1, i32* %P2
+  %V2 = load i32, i32* %P2
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_diamond_clobber1_caller
+define void @test_store_diamond_clobber1_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber1(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_store_diamond_clobber1
+; store P2 and then P1 to preserve order in @test_store_diamond_clobber1
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_store_diamond_clobber2
+define internal void @test_store_diamond_clobber2(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: br
+  store i32 42, i32* %P1
+  store i32 1, i32* %P2
+  %V2 = load i32, i32* %P2
+  br i1 %c, label %st1, label %st2
+
+st1:
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_diamond_clobber2_caller
+define void @test_store_diamond_clobber2_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber2(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_store_diamond_clobber2
+; store P2 and then P1 to preserve order in @test_store_diamond_clobber2
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_store_diamond_clobber3
+define internal void @test_store_diamond_clobber3(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: br
+  store i32 42, i32* %P1
+  store i32 1, i32* %P2
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: br
+st1:
+  %V2 = load i32, i32* %P2
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_diamond_clobber3_caller
+define void @test_store_diamond_clobber3_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber3(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_store_diamond_clobber3
+; store P2 and then P1 to preserve order in @test_store_diamond_clobber3
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal i32 @test_store_diamond_clobber4
+define internal void @test_store_diamond_clobber4(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: br
+  store i32 42, i32* %P1
+  br i1 %c, label %st1, label %st2
+
+st1:
+  store i32 1, i32* %P2
+  %V2 = load i32, i32* %P2
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+define void @test_store_diamond_clobber4_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber4(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_store_diamond_clobber5
+define internal void @test_store_diamond_clobber5(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: store
+  store i32 42, i32* %P1 ; clobbers V2 load on st2 path
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store
+st1:
+  store i32 1, i32* %P2
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  %V2 = load i32, i32* %P2
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+define void @test_store_diamond_clobber5_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber5(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal i32 @test_store_diamond_clobber6
+define internal void @test_store_diamond_clobber6(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: br
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store i32 1, i32* %P2
+st1:
+  store i32 42, i32* %P1
+  store i32 1, i32* %P2
+  br label %exit
+
+st2:
+  br label %exit
+
+exit:
+  %V2 = load i32, i32* %P2
+  store i32 43, i32* %P1 ; this store makes sure that P1 pointee isn't clobbered by P2 store
+  ret void
+}
+
+define void @test_store_diamond_clobber6_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_store_diamond_clobber6(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;------- check clobbering in diamond
+
+;CHECK-LABEL: define internal void @test_clobber1
+define internal void @test_clobber1(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-NEXT: store
+  store i32 42, i32* %P2 ; clobbered by P1 stores, cannot promote
+  %V1 = load i32, i32* %P1 ; clobbered by P2 store above, cannot promote
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store
+st1:
+  store i32 1, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: store
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: exit:
+;CHECK-NEXT: load
+exit:
+  %V2 = load i32, i32* %P1
+  ret void
+}
+
+define void @test_clobber1_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber1(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_clobber2
+define internal void @test_clobber2(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  %V1 = load i32, i32* %P1 ; no clobber
+  store i32 42, i32* %P2 ; clobbered by P1 stores, but unclobbered by P1 promotion
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: br
+st1:
+  store i32 1, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: br
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+exit:
+  %V2 = load i32, i32* %P1 ; no clobber as every path writes by P1
+  ret void
+}
+
+;CHECK-LABEL: define void @test_clobber2_caller
+define void @test_clobber2_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber2(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_clobber2
+; store P2 and then P1 to preserve order in @test_clobber2
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal i32 @test_clobber3
+define internal void @test_clobber3(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  %V1 = load i32, i32* %P1 ; no clobber
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store i32 42, i32* %P2
+;CHECK-NEXT: br
+st1:
+  ; P2 isn't selected for promotion: not all paths have stores and
+  ; not a valid threal-local ptr
+  store i32 42, i32* %P2
+  store i32 1, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: br
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+exit:
+  %V2 = load i32, i32* %P1 ; no clobber as every path writes by P1
+  ret void
+}
+
+;CHECK-LABEL: define void @test_clobber3_caller
+define void @test_clobber3_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber3(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call i32 @test_clobber3
+;CHECK: store i32 %1, i32* %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_clobber4
+define internal void @test_clobber4(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  %V1 = load i32, i32* %P1 ; no clobber
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store i32 1, i32* %P1
+;CHECK-NEXT: store i32 42, i32* %P2
+;CHECK-NEXT: br
+st1:
+  store i32 1, i32* %P1
+  ; P2 isn't selected for promotion: not all paths have stores and
+  ; not a valid threal-local ptr
+  store i32 42, i32* %P2
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: store i32 2, i32* %P1
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+exit:
+  %V2 = load i32, i32* %P1 ; clobbered by P2 write
+  ret void
+}
+
+define void @test_clobber4_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber4(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_clobber5
+define internal void @test_clobber5(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  %V1 = load i32, i32* %P1 ; no clobber
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: store
+st1:
+  store i32 1, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: store
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+exit:
+  store i32 42, i32* %P2 ; clobbers V2 load
+  %V2 = load i32, i32* %P1 ; clobbered by P2 write
+  ret void
+}
+
+define void @test_clobber5_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber5(i1 %c, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_clobber6
+define internal void @test_clobber6(i1 %c, i32* %P1, i32* %P2) { ; P1 may alias P2
+  %V1 = load i32, i32* %P1 ; no clobber
+  br i1 %c, label %st1, label %st2
+
+;CHECK-LABEL: st1:
+;CHECK-NEXT: br
+st1:
+  store i32 1, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: st2:
+;CHECK-NEXT: br
+st2:
+  store i32 2, i32* %P1
+  br label %exit
+
+;CHECK-LABEL: exit:
+;CHECK-NOT: load
+exit:
+  %V2 = load i32, i32* %P1
+  ; P1 pointee is clobbered by P2 write, but unclobbered after P2 promotion
+  store i32 42, i32* %P2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_clobber6_caller
+define void @test_clobber6_caller(i1 %c, i32* %P1, i32* %P2) {
+  call void @test_clobber6(i1 %c, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_clobber6
+;CHECK: store i32 %P1
+;CHECK: store i32 %P2
+  ret void
+}
+
+;------- check clobbering in loops
+
+;CHECK-LABEL: define internal void @test_loop_clobber1
+define internal void @test_loop_clobber1(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: store i32 42, i32* %P2
+;CHECK-NEXT: %V1 = load i32, i32* %P1
+entry:
+  store i32 42, i32* %P2 ; clobbers V1 load
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1 ; clobbers P2 store
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1
+  ret void
+}
+
+define void @test_loop_clobber1_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber1(i32 %n, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_loop_clobber2
+define internal void @test_loop_clobber2(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: br
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 42, i32* %P2 ; clobbered by P1 store, but then unclobbered
+  store i32 1, i32* %P1
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+;CHECK-LABEL: loop:
+;CHECK-NEXT: %i.next = sub i32 %i, 1
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1
+  ret void
+}
+
+;CHECK-LABEL: define void @test_loop_clobber2_caller
+define void @test_loop_clobber2_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber2(i32 %n, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_loop_clobber2
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_loop_clobber3
+define internal void @test_loop_clobber3(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: %V1 = load i32, i32* %P1
+;CHECK-NEXT: store i32 1, i32* %P1
+;CHECK-NEXT: store i32 42, i32* %P2
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  store i32 42, i32* %P2 ; clobbered by P1 store in loop BB
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1 ; clobbered by P2 store
+  ret void
+}
+
+define void @test_loop_clobber3_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber3(i32 %n, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_loop_clobber4
+define internal void @test_loop_clobber4(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: %V1 = load i32, i32* %P1
+;CHECK-NEXT: store i32 1, i32* %P1
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  br label %loop_header
+
+;CHECK-LABEL: loop_header:
+;CHECK: store i32 42, i32* %P2
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  store i32 42, i32* %P2 ; clobbered by P1 store in loop BB
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1 ; clobbered by P2 store
+  ret void
+}
+
+define void @test_loop_clobber4_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber4(i32 %n, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal i32 @test_loop_clobber5
+define internal void @test_loop_clobber5(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: br
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  br label %loop_header
+
+;CHECK-LABEL: loop_header:
+;CHECK-NEXT: %P1.0.val.loop_header.phi = phi i32 [ 2, %loop ], [ 1, %entry ]
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+;CHECK-LABEL: loop:
+;CHECK-NEXT: store i32 42, i32* %P2
+;CHECK-NEXT: %i.next = sub i32 %i, 1
+loop:
+  store i32 42, i32* %P2 ; not selected for promotion (no stores at every path)
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1
+  ret void
+}
+
+;CHECK-LABEL: define void @test_loop_clobber5_caller
+define void @test_loop_clobber5_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber5(i32 %n, i32* %P1, i32* %P2)
+;CHECK: %1 = call i32 @test_loop_clobber5
+;CHECK: store i32 %1, i32* %P1
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_loop_clobber6
+define internal void @test_loop_clobber6(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: %V1 = load i32, i32* %P1
+;CHECK-NEXT: store i32 1, i32* %P1
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+;CHECK-LABEL: loop:
+;CHECK-NEXT: store i32 2, i32* %P1
+;CHECK-NEXT: store i32 42, i32* %P2
+loop:
+  store i32 2, i32* %P1
+  store i32 42, i32* %P2 ; not selected for promotion (no stores at every path)
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1 ; clobbered by P2 store
+  ret void
+}
+
+define void @test_loop_clobber6_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber6(i32 %n, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_loop_clobber7
+define internal void @test_loop_clobber7(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: %V1 = load i32, i32* %P1
+;CHECK-NEXT: store i32 1, i32* %P1
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+;CHECK-LABEL: exit:
+;CHECK-NEXT: store i32 42, i32* %P2
+exit:
+  store i32 42, i32* %P2 ; clobbers V2 load
+  %V2 = load i32, i32* %P1 ; clobbered by P2 store
+  ret void
+}
+
+define void @test_loop_clobber7_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber7(i32 %n, i32* %P1, i32* %P2)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal { i32, i32 } @test_loop_clobber8
+define internal void @test_loop_clobber8(i32 %n, i32* %P1, i32* %P2) { ; P1 may alias P2
+;CHECK-LABEL: entry:
+;CHECK-NEXT: br
+entry:
+  %V1 = load i32, i32* %P1
+  store i32 1, i32* %P1
+  br label %loop_header
+
+loop_header:
+  %i = phi i32 [%i.next, %loop], [%n, %entry]
+  %c = icmp eq i32 %i, 0
+  br i1 %c, label %exit, label %loop
+
+;CHECK-LABEL: loop:
+;CHECK-NEXT: %i.next = sub i32 %i, 1
+loop:
+  store i32 2, i32* %P1
+  %i.next = sub i32 %i, 1
+  br label %loop_header
+
+exit:
+  %V2 = load i32, i32* %P1
+  store i32 42, i32* %P2 ; clobbers P1 pointee but it is unclobbered after P2 promotion
+  ret void
+}
+
+;CHECK-LABEL: define void @test_loop_clobber8_caller
+define void @test_loop_clobber8_caller(i32 %n, i32* %P1, i32* %P2) {
+  call void @test_loop_clobber8(i32 %n, i32* %P1, i32* %P2)
+;CHECK: %1 = call { i32, i32 } @test_loop_clobber8
+;CHECK: store i32 %P1
+;CHECK: store i32 %P2
+  ret void
+}
+
+; -----------------------------------------------------------------------------
+; Test declobbering sequences
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber1
+define internal void @test_store_unclobber1(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 1, i32* %P1
+  store i32 2, i32* %P2
+  store i32 3, i32* %P3
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber1_caller
+define void @test_store_unclobber1_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber1(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber1
+;CHECK: store i32 %P1
+;CHECK: store i32 %P2
+;CHECK: store i32 %P3
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber2
+define internal void @test_store_unclobber2(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 1, i32* %P1
+  store i32 3, i32* %P3
+  store i32 2, i32* %P2
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber2_caller
+define void @test_store_unclobber2_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber2(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber2
+;CHECK: store i32 %P1
+;CHECK: store i32 %P3
+;CHECK: store i32 %P2
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber3
+define internal void @test_store_unclobber3(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 2, i32* %P2
+  store i32 1, i32* %P1
+  store i32 3, i32* %P3
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber3_caller
+define void @test_store_unclobber3_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber3(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber3
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+;CHECK: store i32 %P3
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber4
+define internal void @test_store_unclobber4(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 2, i32* %P2
+  store i32 3, i32* %P3
+  store i32 1, i32* %P1
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber4_caller
+define void @test_store_unclobber4_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber4(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber4
+;CHECK: store i32 %P2
+;CHECK: store i32 %P3
+;CHECK: store i32 %P1
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber5
+define internal void @test_store_unclobber5(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 3, i32* %P3
+  store i32 1, i32* %P1
+  store i32 2, i32* %P2
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber5_caller
+define void @test_store_unclobber5_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber5(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber5
+;CHECK: store i32 %P3
+;CHECK: store i32 %P1
+;CHECK: store i32 %P2
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber6
+define internal void @test_store_unclobber6(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 3, i32* %P3
+  store i32 2, i32* %P2
+  store i32 1, i32* %P1
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 1, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 2, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 3, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber6_caller
+define void @test_store_unclobber6_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber6(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 } @test_store_unclobber6
+;CHECK: store i32 %P3
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+;CHECK-LABEL: define internal { i32, i32, i32 } @test_store_unclobber6_2x
+define internal void @test_store_unclobber6_2x(i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 3, i32* %P3
+  store i32 2, i32* %P2
+  store i32 1, i32* %P1
+
+  store i32 5, i32* %P3
+  store i32 6, i32* %P2
+  store i32 4, i32* %P1
+; note that values are inserted in the order of arguments of the function
+;CHECK: [[R:%[a-zA-Z0-9_]+]].ret0 = insertvalue { i32, i32, i32 } undef, i32 4, 0
+;CHECK-DAG: [[R]].ret1 = insertvalue { i32, i32, i32 } [[R]].ret0, i32 6, 1
+;CHECK-DAG: [[R]].ret2 = insertvalue { i32, i32, i32 } [[R]].ret1, i32 5, 2
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber6_2x_caller
+define void @test_store_unclobber6_2x_caller(i32* %P1, i32* %P2, i32* %P3) {
+  call void @test_store_unclobber6_2x(i32* %P1, i32* %P2, i32* %P3)
+;CHECK: %1 = call { i32, i32, i32 }
+;CHECK: store i32 %P3
+;CHECK: store i32 %P2
+;CHECK: store i32 %P1
+  ret void
+}
+
+;CHECK-LABEL: define internal void @test_store_unclobber_fail1
+define internal void @test_store_unclobber_fail1(i1 %c, i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 3, i32* %P1
+  br i1 %c, label %st1, label %st2
+st1:
+  store i32 1, i32* %P2
+  store i32 2, i32* %P3
+  br label %exit
+st2:
+  store i32 1, i32* %P3
+  store i32 2, i32* %P2
+  br label %exit
+exit:
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber_fail1_caller
+define void @test_store_unclobber_fail1_caller(i1 %c, i32* %P1, i32* %P2, i32* %P3) {
+; CHECK: call void
+  call void @test_store_unclobber_fail1(i1 %c, i32* %P1, i32* %P2, i32* %P3)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_store_unclobber_fail2
+define internal void @test_store_unclobber_fail2(i1 %c, i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 1, i32* %P2
+  br i1 %c, label %st1, label %st2
+st1:
+  store i32 3, i32* %P1
+  store i32 2, i32* %P3
+  br label %exit
+st2:
+  store i32 1, i32* %P3
+  store i32 3, i32* %P1
+  br label %exit
+exit:
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber_fail2_caller
+define void @test_store_unclobber_fail2_caller(i1 %c, i32* %P1, i32* %P2, i32* %P3) {
+; CHECK: call void
+  call void @test_store_unclobber_fail2(i1 %c, i32* %P1, i32* %P2, i32* %P3)
+  ret void
+}
+
+
+;CHECK-LABEL: define internal void @test_store_unclobber_fail3
+define internal void @test_store_unclobber_fail3(i1 %c, i32* %P1, i32* %P2, i32* %P3) { ; P1, P2, P3 may alias
+  store i32 2, i32* %P3
+  br i1 %c, label %st1, label %st2
+st1:
+  store i32 3, i32* %P1
+  store i32 1, i32* %P2
+  br label %exit
+st2:
+  store i32 1, i32* %P2
+  store i32 3, i32* %P1
+  br label %exit
+exit:
+  ret void
+}
+
+;CHECK-LABEL: define void @test_store_unclobber_fail3_caller
+define void @test_store_unclobber_fail3_caller(i1 %c, i32* %P1, i32* %P2, i32* %P3) {
+; CHECK: call void
+  call void @test_store_unclobber_fail3(i1 %c, i32* %P1, i32* %P2, i32* %P3)
+  ret void
+}
+
+; -----------------------------------------------------------------------------
+; Test declobbering in a more complicated CFG
+;CHECK-LABEL: define internal { i32, i32, i32 } @nested_diamond
+define internal i32 @nested_diamond(i1 %D1C, i1 %D2C, i32 %X, i32 %Y, i32 *%P1, i32* %P2) {
+;        D1
+;      /   \
+;    D2     \
+; D2L  D2R   D1R
+;    D2E    /
+;      \   /
+;       D1E
+D1:
+  br i1 %D1C, label %D2, label %D1R
+
+D2:
+  br i1 %D2C, label %D2L, label %D2R
+
+D2L:
+;CHECK-LABEL: D2L:
+;CHECK-NEXT: br
+  store i32 %Y, i32* %P1
+  store i32 %X, i32* %P1
+  store i32 %X, i32* %P2
+  store i32 %Y, i32* %P2
+  br label %D2E
+
+D2R:
+;CHECK-LABEL: D2R:
+;CHECK-NEXT: br
+  store i32 %Y, i32* %P1
+  store i32 %X, i32* %P2
+  br label %D2E
+
+D2E:
+;CHECK-LABEL: D2E:
+;CHECK-NEXT: %P1.0.val.D2E.phi = phi i32 [ %Y, %D2R ], [ %X, %D2L ]
+;CHECK-NEXT: %P2.0.val.D2E.phi = phi i32 [ %X, %D2R ], [ %Y, %D2L ]
+  br label %D1E
+
+D1R:
+;CHECK-LABEL: D1R:
+;CHECK-NEXT: br
+  store i32 %X, i32* %P1
+  store i32 %Y, i32* %P2
+  br label %D1E
+
+D1E:
+;CHECK-LABEL: D1E:
+;CHECK-NEXT: %P1.0.val.D1E.phi = phi i32 [ %X, %D1R ], [ %P1.0.val.D2E.phi, %D2E ]
+;CHECK-NEXT: %P2.0.val.D1E.phi = phi i32 [ %Y, %D1R ], [ %P2.0.val.D2E.phi, %D2E ]
+;CHECK-NEXT: [[R1:%.*]] = insertvalue { i32, i32, i32 } undef, i32 42, 0
+;CHECK-NEXT: [[R2:%.*]] = insertvalue { i32, i32, i32 } [[R1]], i32 %P1.0.val.D1E.phi, 1
+;CHECK-NEXT: [[R3:%.*]] = insertvalue { i32, i32, i32 } [[R2]], i32 %P2.0.val.D1E.phi, 2
+;CHECK-NEXT: ret { i32, i32, i32 } [[R3]]
+  ret i32 42
+}
+
+;CHECK-LABEL: define i32 @nested_diamond_caller
+define i32 @nested_diamond_caller(i1 %D1C, i1 %D2C, i32 %X, i32 %Y, i32* %P1, i32* %P2) {
+  %C = call i32 @nested_diamond(i1 %D1C, i1 %D2C, i32 %X, i32 %Y, i32* %P1, i32* %P2)
+; CHECK: %C = call { i32, i32, i32 } @nested_diamond(i1 %D1C, i1 %D2C, i32 %X, i32 %Y)
+; CHECK-NEXT: %P1.val.ret = extractvalue { i32, i32, i32 } %C, 1
+; CHECK-NEXT: store i32 %P1.val.ret, i32* %P1, align 4
+; CHECK-NEXT: %P2.val.ret = extractvalue { i32, i32, i32 } %C, 2
+; CHECK-NEXT: store i32 %P2.val.ret, i32* %P2, align 4
+  %V1 = load i32, i32* %P1
+  %V2 = load i32, i32* %P2
+  %Sum = add i32 %V1, %V2
+  ret i32 %Sum
+}
diff --git a/llvm/test/Transforms/ArgumentPromotion/opaque-ptr.ll b/llvm/test/Transforms/ArgumentPromotion/opaque-ptr.ll
--- a/llvm/test/Transforms/ArgumentPromotion/opaque-ptr.ll
+++ b/llvm/test/Transforms/ArgumentPromotion/opaque-ptr.ll
@@ -1,11 +1,20 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --function-signature --scrub-attributes
 ; RUN: opt -S -argpromotion -opaque-pointers < %s | FileCheck %s
+; RUN: opt -S -mssaargpromotion -opaque-pointers < %s | FileCheck -check-prefix=MSSA %s
 
 define internal i32 @callee_basic(ptr %p) {
 ; CHECK-LABEL: define {{[^@]+}}@callee_basic
 ; CHECK-SAME: (i32 [[P_0_VAL:%.*]], i32 [[P_4_VAL:%.*]]) {
 ; CHECK-NEXT:    [[Z:%.*]] = add i32 [[P_0_VAL]], [[P_4_VAL]]
 ; CHECK-NEXT:    ret i32 [[Z]]
+;
+; MSSA-LABEL: define {{[^@]+}}@callee_basic
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[X:%.*]] = load i32, ptr [[P]], align 4
+; MSSA-NEXT:    [[P1:%.*]] = getelementptr i8, ptr [[P]], i64 4
+; MSSA-NEXT:    [[Y:%.*]] = load i32, ptr [[P1]], align 4
+; MSSA-NEXT:    [[Z:%.*]] = add i32 [[X]], [[Y]]
+; MSSA-NEXT:    ret i32 [[Z]]
 ;
   %x = load i32, ptr %p
   %p1 = getelementptr i8, ptr %p, i64 4
@@ -22,11 +31,50 @@
 ; CHECK-NEXT:    [[P_VAL1:%.*]] = load i32, ptr [[TMP1]], align 4
 ; CHECK-NEXT:    [[TMP2:%.*]] = call i32 @callee_basic(i32 [[P_VAL]], i32 [[P_VAL1]])
 ; CHECK-NEXT:    ret void
+;
+; MSSA-LABEL: define {{[^@]+}}@caller_basic
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[TMP1:%.*]] = call i32 @callee_basic(ptr [[P]])
+; MSSA-NEXT:    ret void
 ;
   call i32 @callee_basic(ptr %p)
   ret void
 }
 
+define internal i32 @callee_basic_nogeps(ptr %p) {
+; CHECK-LABEL: define {{[^@]+}}@callee_basic_nogeps
+; CHECK-SAME: (i32 [[P_0_VAL:%.*]]) {
+; CHECK-NEXT:    [[Z:%.*]] = add i32 [[P_0_VAL]], [[P_0_VAL]]
+; CHECK-NEXT:    ret i32 [[Z]]
+;
+; MSSA-LABEL: define {{[^@]+}}@callee_basic_nogeps
+; MSSA-SAME: (i32 [[P_0_VAL:%.*]]) {
+; MSSA-NEXT:    [[Z:%.*]] = add i32 [[P_0_VAL]], [[P_0_VAL]]
+; MSSA-NEXT:    ret i32 [[Z]]
+;
+  %x = load i32, ptr %p
+  %y = load i32, ptr %p
+  %z = add i32 %x, %y
+  ret i32 %z
+}
+
+define void @caller_basic_nogeps(ptr %p) {
+; CHECK-LABEL: define {{[^@]+}}@caller_basic_nogeps
+; CHECK-SAME: (ptr [[P:%.*]]) {
+; CHECK-NEXT:    [[P_VAL:%.*]] = load i32, ptr [[P]], align 4
+; CHECK-NEXT:    [[TMP1:%.*]] = call i32 @callee_basic_nogeps(i32 [[P_VAL]])
+; CHECK-NEXT:    ret void
+;
+; MSSA-LABEL: define {{[^@]+}}@caller_basic_nogeps
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[P_VAL:%.*]] = load i32, ptr [[P]], align 4
+; MSSA-NEXT:    [[TMP1:%.*]] = call i32 @callee_basic_nogeps(i32 [[P_VAL]])
+; MSSA-NEXT:    ret void
+;
+  call i32 @callee_basic_nogeps(ptr %p)
+  ret void
+}
+
 ; Same offset is loaded with two differen types: Don't promote.
 define internal i32 @callee_different_types(ptr %p) {
 ; CHECK-LABEL: define {{[^@]+}}@callee_different_types
@@ -36,6 +84,14 @@
 ; CHECK-NEXT:    [[Y:%.*]] = fptoui float [[Y_F]] to i32
 ; CHECK-NEXT:    [[Z:%.*]] = add i32 [[X]], [[Y]]
 ; CHECK-NEXT:    ret i32 [[Z]]
+;
+; MSSA-LABEL: define {{[^@]+}}@callee_different_types
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[X:%.*]] = load i32, ptr [[P]], align 4
+; MSSA-NEXT:    [[Y_F:%.*]] = load float, ptr [[P]], align 4
+; MSSA-NEXT:    [[Y:%.*]] = fptoui float [[Y_F]] to i32
+; MSSA-NEXT:    [[Z:%.*]] = add i32 [[X]], [[Y]]
+; MSSA-NEXT:    ret i32 [[Z]]
 ;
   %x = load i32, ptr %p
   %y.f = load float, ptr %p
@@ -49,6 +105,11 @@
 ; CHECK-SAME: (ptr [[P:%.*]]) {
 ; CHECK-NEXT:    [[TMP1:%.*]] = call i32 @callee_different_types(ptr [[P]])
 ; CHECK-NEXT:    ret void
+;
+; MSSA-LABEL: define {{[^@]+}}@caller_different_types
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[TMP1:%.*]] = call i32 @callee_different_types(ptr [[P]])
+; MSSA-NEXT:    ret void
 ;
   call i32 @callee_different_types(ptr %p)
   ret void
@@ -63,6 +124,14 @@
 ; CHECK-NEXT:    [[Y:%.*]] = load i32, ptr [[P1]], align 4
 ; CHECK-NEXT:    [[Z:%.*]] = add i32 [[X]], [[Y]]
 ; CHECK-NEXT:    ret i32 [[Z]]
+;
+; MSSA-LABEL: define {{[^@]+}}@callee_overlap
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[X:%.*]] = load i32, ptr [[P]], align 4
+; MSSA-NEXT:    [[P1:%.*]] = getelementptr i8, ptr [[P]], i64 2
+; MSSA-NEXT:    [[Y:%.*]] = load i32, ptr [[P1]], align 4
+; MSSA-NEXT:    [[Z:%.*]] = add i32 [[X]], [[Y]]
+; MSSA-NEXT:    ret i32 [[Z]]
 ;
   %x = load i32, ptr %p
   %p1 = getelementptr i8, ptr %p, i64 2
@@ -76,6 +145,11 @@
 ; CHECK-SAME: (ptr [[P:%.*]]) {
 ; CHECK-NEXT:    [[TMP1:%.*]] = call i32 @callee_overlap(ptr [[P]])
 ; CHECK-NEXT:    ret void
+;
+; MSSA-LABEL: define {{[^@]+}}@caller_overlap
+; MSSA-SAME: (ptr [[P:%.*]]) {
+; MSSA-NEXT:    [[TMP1:%.*]] = call i32 @callee_overlap(ptr [[P]])
+; MSSA-NEXT:    ret void
 ;
   call i32 @callee_overlap(ptr %p)
   ret void