X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FTransforms%2FIPO%2FArgumentPromotion.cpp;h=dc26312028f344b491e26e48df7ed73ae1f93632;hb=2f69477cfd7ee5277dbfb4123c3e7ae2b5f64c21;hp=f14c62b136e1517f4653cbc3dad1d6ec5b2b0c11;hpb=ae0a7bc68303ce0c8721f0e981ae602601390e68;p=oota-llvm.git

diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp
index f14c62b136e..dc26312028f 100644
--- a/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -29,27 +29,29 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "argpromotion"
 #include "llvm/Transforms/IPO.h"
-#include "llvm/Constants.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Module.h"
-#include "llvm/CallGraphSCCPass.h"
-#include "llvm/Instructions.h"
-#include "llvm/LLVMContext.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/Analysis/AliasAnalysis.h"
 #include "llvm/Analysis/CallGraph.h"
-#include "llvm/Target/TargetData.h"
-#include "llvm/Support/CallSite.h"
-#include "llvm/Support/CFG.h"
+#include "llvm/Analysis/CallGraphSCCPass.h"
+#include "llvm/IR/CFG.h"
+#include "llvm/IR/CallSite.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DebugInfo.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/StringExtras.h"
 #include <set>
 using namespace llvm;
 
+#define DEBUG_TYPE "argpromotion"
+
 STATISTIC(NumArgumentsPromoted , "Number of pointer arguments promoted");
 STATISTIC(NumAggregatesPromoted, "Number of aggregate arguments promoted");
 STATISTIC(NumByValArgsPromoted , "Number of byval arguments promoted");
@@ -59,27 +61,35 @@ namespace {
   /// ArgPromotion - The 'by reference' to 'by value' argument promotion pass.
   ///
   struct ArgPromotion : public CallGraphSCCPass {
-    virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
       AU.addRequired<AliasAnalysis>();
       CallGraphSCCPass::getAnalysisUsage(AU);
     }
 
-    virtual bool runOnSCC(CallGraphSCC &SCC);
+    bool runOnSCC(CallGraphSCC &SCC) override;
     static char ID; // Pass identification, replacement for typeid
     explicit ArgPromotion(unsigned maxElements = 3)
-      : CallGraphSCCPass(ID), maxElements(maxElements) {}
+        : CallGraphSCCPass(ID), maxElements(maxElements) {
+      initializeArgPromotionPass(*PassRegistry::getPassRegistry());
+    }
 
     /// A vector used to hold the indices of a single GEP instruction
     typedef std::vector<uint64_t> IndicesVector;
 
   private:
+    bool isDenselyPacked(Type *type, const DataLayout &DL);
+    bool canPaddingBeAccessed(Argument *Arg);
     CallGraphNode *PromoteArguments(CallGraphNode *CGN);
     bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const;
     CallGraphNode *DoPromotion(Function *F,
-                               SmallPtrSet<Argument*, 8> &ArgsToPromote,
-                               SmallPtrSet<Argument*, 8> &ByValArgsToTransform);
+                              SmallPtrSetImpl<Argument*> &ArgsToPromote,
+                              SmallPtrSetImpl<Argument*> &ByValArgsToTransform);
+    
+    using llvm::Pass::doInitialization;
+    bool doInitialization(CallGraph &CG) override;
     /// The maximum number of elements to expand, or 0 for unlimited.
     unsigned maxElements;
+    DenseMap<const Function *, DISubprogram> FunctionDIs;
   };
 }
 
@@ -87,7 +97,7 @@ char ArgPromotion::ID = 0;
 INITIALIZE_PASS_BEGIN(ArgPromotion, "argpromotion",
                 "Promote 'by reference' arguments to scalars", false, false)
 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
-INITIALIZE_AG_DEPENDENCY(CallGraph)
+INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
 INITIALIZE_PASS_END(ArgPromotion, "argpromotion",
                 "Promote 'by reference' arguments to scalars", false, false)
 
@@ -113,6 +123,79 @@ bool ArgPromotion::runOnSCC(CallGraphSCC &SCC) {
   return Changed;
 }
 
+/// \brief Checks if a type could have padding bytes.
+bool ArgPromotion::isDenselyPacked(Type *type, const DataLayout &DL) {
+
+  // There is no size information, so be conservative.
+  if (!type->isSized())
+    return false;
+
+  // If the alloc size is not equal to the storage size, then there are padding
+  // bytes. For x86_fp80 on x86-64, size: 80 alloc size: 128.
+  if (DL.getTypeSizeInBits(type) != DL.getTypeAllocSizeInBits(type))
+    return false;
+
+  if (!isa<CompositeType>(type))
+    return true;
+
+  // For homogenous sequential types, check for padding within members.
+  if (SequentialType *seqTy = dyn_cast<SequentialType>(type))
+    return isa<PointerType>(seqTy) ||
+           isDenselyPacked(seqTy->getElementType(), DL);
+
+  // Check for padding within and between elements of a struct.
+  StructType *StructTy = cast<StructType>(type);
+  const StructLayout *Layout = DL.getStructLayout(StructTy);
+  uint64_t StartPos = 0;
+  for (unsigned i = 0, E = StructTy->getNumElements(); i < E; ++i) {
+    Type *ElTy = StructTy->getElementType(i);
+    if (!isDenselyPacked(ElTy, DL))
+      return false;
+    if (StartPos != Layout->getElementOffsetInBits(i))
+      return false;
+    StartPos += DL.getTypeAllocSizeInBits(ElTy);
+  }
+
+  return true;
+}
+
+/// \brief Checks if the padding bytes of an argument could be accessed.
+bool ArgPromotion::canPaddingBeAccessed(Argument *arg) {
+
+  assert(arg->hasByValAttr());
+
+  // Track all the pointers to the argument to make sure they are not captured.
+  SmallPtrSet<Value *, 16> PtrValues;
+  PtrValues.insert(arg);
+
+  // Track all of the stores.
+  SmallVector<StoreInst *, 16> Stores;
+
+  // Scan through the uses recursively to make sure the pointer is always used
+  // sanely.
+  SmallVector<Value *, 16> WorkList;
+  WorkList.insert(WorkList.end(), arg->user_begin(), arg->user_end());
+  while (!WorkList.empty()) {
+    Value *V = WorkList.back();
+    WorkList.pop_back();
+    if (isa<GetElementPtrInst>(V) || isa<PHINode>(V)) {
+      if (PtrValues.insert(V).second)
+        WorkList.insert(WorkList.end(), V->user_begin(), V->user_end());
+    } else if (StoreInst *Store = dyn_cast<StoreInst>(V)) {
+      Stores.push_back(Store);
+    } else if (!isa<LoadInst>(V)) {
+      return true;
+    }
+  }
+
+// Check to make sure the pointers aren't captured
+  for (StoreInst *Store : Stores)
+    if (PtrValues.count(Store->getValueOperand()))
+      return true;
+
+  return false;
+}
+
 /// PromoteArguments - This method checks the specified function to see if there
 /// are any promotable arguments and if it is safe to promote the function (for
 /// example, all callers are direct).  If safe to promote some arguments, it
@@ -122,100 +205,122 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
   Function *F = CGN->getFunction();
 
   // Make sure that it is local to this module.
-  if (!F || !F->hasLocalLinkage()) return 0;
+  if (!F || !F->hasLocalLinkage()) return nullptr;
 
   // First check: see if there are any pointer arguments!  If not, quick exit.
-  SmallVector<std::pair<Argument*, unsigned>, 16> PointerArgs;
-  unsigned ArgNo = 0;
-  for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end();
-       I != E; ++I, ++ArgNo)
+  SmallVector<Argument*, 16> PointerArgs;
+  for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
     if (I->getType()->isPointerTy())
-      PointerArgs.push_back(std::pair<Argument*, unsigned>(I, ArgNo));
-  if (PointerArgs.empty()) return 0;
+      PointerArgs.push_back(I);
+  if (PointerArgs.empty()) return nullptr;
 
   // Second check: make sure that all callers are direct callers.  We can't
-  // transform functions that have indirect callers.
-  if (F->hasAddressTaken())
-    return 0;
+  // transform functions that have indirect callers.  Also see if the function
+  // is self-recursive.
+  bool isSelfRecursive = false;
+  for (Use &U : F->uses()) {
+    CallSite CS(U.getUser());
+    // Must be a direct call.
+    if (CS.getInstruction() == nullptr || !CS.isCallee(&U)) return nullptr;
+    
+    if (CS.getInstruction()->getParent()->getParent() == F)
+      isSelfRecursive = true;
+  }
+  
+  // 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;
+  const DataLayout &DL = F->getParent()->getDataLayout();
 
   // Check to see which arguments are promotable.  If an argument is promotable,
   // add it to ArgsToPromote.
   SmallPtrSet<Argument*, 8> ArgsToPromote;
   SmallPtrSet<Argument*, 8> ByValArgsToTransform;
-  for (unsigned i = 0; i != PointerArgs.size(); ++i) {
-    bool isByVal = F->paramHasAttr(PointerArgs[i].second+1, Attribute::ByVal);
+  for (unsigned i = 0, e = PointerArgs.size(); i != e; ++i) {
+    Argument *PtrArg = PointerArgs[i];
+    Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType();
 
     // If this is a byval argument, and if the aggregate type is small, just
-    // pass the elements, which is always safe.
-    Argument *PtrArg = PointerArgs[i].first;
-    if (isByVal) {
-      const Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType();
-      if (const StructType *STy = dyn_cast<StructType>(AgTy)) {
+    // pass the elements, which is always safe, if the passed value is densely
+    // packed or if we can prove the padding bytes are never accessed. This does
+    // not apply to inalloca.
+    bool isSafeToPromote =
+        PtrArg->hasByValAttr() &&
+        (isDenselyPacked(AgTy, DL) || !canPaddingBeAccessed(PtrArg));
+    if (isSafeToPromote) {
+      if (StructType *STy = dyn_cast<StructType>(AgTy)) {
         if (maxElements > 0 && STy->getNumElements() > maxElements) {
           DEBUG(dbgs() << "argpromotion disable promoting argument '"
                 << PtrArg->getName() << "' because it would require adding more"
                 << " than " << maxElements << " arguments to the function.\n");
-        } else {
-          // If all the elements are single-value types, we can promote it.
-          bool AllSimple = true;
-          for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
-            if (!STy->getElementType(i)->isSingleValueType()) {
-              AllSimple = false;
-              break;
-            }
-
-          // Safe to transform, don't even bother trying to "promote" it.
-          // Passing the elements as a scalar will allow scalarrepl to hack on
-          // the new alloca we introduce.
-          if (AllSimple) {
-            ByValArgsToTransform.insert(PtrArg);
-            continue;
+          continue;
+        }
+        
+        // If all the elements are single-value types, we can promote it.
+        bool AllSimple = true;
+        for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+          if (!STy->getElementType(i)->isSingleValueType()) {
+            AllSimple = false;
+            break;
           }
         }
+
+        // Safe to transform, don't even bother trying to "promote" it.
+        // Passing the elements as a scalar will allow scalarrepl to hack on
+        // the new alloca we introduce.
+        if (AllSimple) {
+          ByValArgsToTransform.insert(PtrArg);
+          continue;
+        }
       }
     }
 
+    // If the argument is a recursive type and we're in a recursive
+    // function, we could end up infinitely peeling the function argument.
+    if (isSelfRecursive) {
+      if (StructType *STy = dyn_cast<StructType>(AgTy)) {
+        bool RecursiveType = false;
+        for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
+          if (STy->getElementType(i) == PtrArg->getType()) {
+            RecursiveType = true;
+            break;
+          }
+        }
+        if (RecursiveType)
+          continue;
+      }
+    }
+    
     // Otherwise, see if we can promote the pointer to its value.
-    if (isSafeToPromoteArgument(PtrArg, isByVal))
+    if (isSafeToPromoteArgument(PtrArg, PtrArg->hasByValOrInAllocaAttr()))
       ArgsToPromote.insert(PtrArg);
   }
 
   // No promotable pointer arguments.
   if (ArgsToPromote.empty() && ByValArgsToTransform.empty()) 
-    return 0;
+    return nullptr;
 
   return DoPromotion(F, ArgsToPromote, ByValArgsToTransform);
 }
 
-/// IsAlwaysValidPointer - Return true if the specified pointer is always legal
-/// to load.
-static bool IsAlwaysValidPointer(Value *V) {
-  if (isa<AllocaInst>(V) || isa<GlobalVariable>(V)) return true;
-  if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V))
-    return IsAlwaysValidPointer(GEP->getOperand(0));
-  if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
-    if (CE->getOpcode() == Instruction::GetElementPtr)
-      return IsAlwaysValidPointer(CE->getOperand(0));
-
-  return false;
-}
-
-/// AllCalleesPassInValidPointerForArgument - Return true if we can prove that
+/// AllCallersPassInValidPointerForArgument - Return true if we can prove that
 /// all callees pass in a valid pointer for the specified function argument.
-static bool AllCalleesPassInValidPointerForArgument(Argument *Arg) {
+static bool AllCallersPassInValidPointerForArgument(Argument *Arg) {
   Function *Callee = Arg->getParent();
+  const DataLayout &DL = Callee->getParent()->getDataLayout();
 
-  unsigned ArgNo = std::distance(Callee->arg_begin(),
-                                 Function::arg_iterator(Arg));
+  unsigned ArgNo = Arg->getArgNo();
 
   // Look at all call sites of the function.  At this pointer we know we only
   // have direct callees.
-  for (Value::use_iterator UI = Callee->use_begin(), E = Callee->use_end();
-       UI != E; ++UI) {
-    CallSite CS(*UI);
+  for (User *U : Callee->users()) {
+    CallSite CS(U);
     assert(CS && "Should only have direct calls!");
 
-    if (!IsAlwaysValidPointer(CS.getArgument(ArgNo)))
+    if (!CS.getArgument(ArgNo)->isDereferenceablePointer(DL))
       return false;
   }
   return true;
@@ -230,10 +335,7 @@ static bool IsPrefix(const ArgPromotion::IndicesVector &Prefix,
                      const ArgPromotion::IndicesVector &Longer) {
   if (Prefix.size() > Longer.size())
     return false;
-  for (unsigned i = 0, e = Prefix.size(); i != e; ++i)
-    if (Prefix[i] != Longer[i])
-      return false;
-  return true;
+  return std::equal(Prefix.begin(), Prefix.end(), Longer.begin());
 }
 
 
@@ -293,7 +395,8 @@ static void MarkIndicesSafe(const ArgPromotion::IndicesVector &ToMark,
 /// This method limits promotion of aggregates to only promote up to three
 /// elements of the aggregate in order to avoid exploding the number of
 /// arguments passed in.
-bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
+bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
+                                           bool isByValOrInAlloca) const {
   typedef std::set<IndicesVector> GEPIndicesSet;
 
   // Quick exit for unused arguments
@@ -315,6 +418,9 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   //
   // This set will contain all sets of indices that are loaded in the entry
   // block, and thus are safe to unconditionally load in the caller.
+  //
+  // This optimization is also safe for InAlloca parameters, because it verifies
+  // that the address isn't captured.
   GEPIndicesSet SafeToUnconditionallyLoad;
 
   // This set contains all the sets of indices that we are planning to promote.
@@ -322,7 +428,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   GEPIndicesSet ToPromote;
 
   // If the pointer is always valid, any load with first index 0 is valid.
-  if (isByVal || AllCalleesPassInValidPointerForArgument(Arg))
+  if (isByValOrInAlloca || AllCallersPassInValidPointerForArgument(Arg))
     SafeToUnconditionallyLoad.insert(IndicesVector(1, 0));
 
   // First, iterate the entry block and mark loads of (geps of) arguments as
@@ -362,16 +468,16 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   // not (GEP+)loads, or any (GEP+)loads that are not safe to promote.
   SmallVector<LoadInst*, 16> Loads;
   IndicesVector Operands;
-  for (Value::use_iterator UI = Arg->use_begin(), E = Arg->use_end();
-       UI != E; ++UI) {
-    User *U = *UI;
+  for (Use &U : Arg->uses()) {
+    User *UR = U.getUser();
     Operands.clear();
-    if (LoadInst *LI = dyn_cast<LoadInst>(U)) {
-      if (LI->isVolatile()) return false;  // Don't hack volatile loads
+    if (LoadInst *LI = dyn_cast<LoadInst>(UR)) {
+      // Don't hack volatile/atomic loads
+      if (!LI->isSimple()) return false;
       Loads.push_back(LI);
       // Direct loads are equivalent to a GEP with a zero index and then a load.
       Operands.push_back(0);
-    } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(U)) {
+    } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(UR)) {
       if (GEP->use_empty()) {
         // Dead GEP's cause trouble later.  Just remove them if we run into
         // them.
@@ -380,7 +486,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
         // TODO: This runs the above loop over and over again for dead GEPs
         // Couldn't we just do increment the UI iterator earlier and erase the
         // use?
-        return isSafeToPromoteArgument(Arg, isByVal);
+        return isSafeToPromoteArgument(Arg, isByValOrInAlloca);
       }
 
       // Ensure that all of the indices are constants.
@@ -392,10 +498,10 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
           return false;  // Not a constant operand GEP!
 
       // Ensure that the only users of the GEP are load instructions.
-      for (Value::use_iterator UI = GEP->use_begin(), E = GEP->use_end();
-           UI != E; ++UI)
-        if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) {
-          if (LI->isVolatile()) return false;  // Don't hack volatile loads
+      for (User *GEPU : GEP->users())
+        if (LoadInst *LI = dyn_cast<LoadInst>(GEPU)) {
+          // Don't hack volatile/atomic loads
+          if (!LI->isSimple()) return false;
           Loads.push_back(LI);
         } else {
           // Other uses than load?
@@ -422,7 +528,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
         // of elements of the aggregate.
         return false;
       }
-      ToPromote.insert(Operands);
+      ToPromote.insert(std::move(Operands));
     }
   }
 
@@ -438,8 +544,6 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
   SmallPtrSet<BasicBlock*, 16> TranspBlocks;
 
   AliasAnalysis &AA = getAnalysis<AliasAnalysis>();
-  TargetData *TD = getAnalysisIfAvailable<TargetData>();
-  if (!TD) return false; // Without TargetData, assume the worst.
 
   for (unsigned i = 0, e = Loads.size(); i != e; ++i) {
     // Check to see if the load is invalidated from the start of the block to
@@ -447,22 +551,17 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
     LoadInst *Load = Loads[i];
     BasicBlock *BB = Load->getParent();
 
-    const PointerType *LoadTy =
-      cast<PointerType>(Load->getPointerOperand()->getType());
-    unsigned LoadSize =(unsigned)TD->getTypeStoreSize(LoadTy->getElementType());
-
-    if (AA.canInstructionRangeModify(BB->front(), *Load, Arg, LoadSize))
+    AliasAnalysis::Location Loc = AA.getLocation(Load);
+    if (AA.canInstructionRangeModRef(BB->front(), *Load, Loc,
+        AliasAnalysis::Mod))
       return false;  // Pointer is invalidated!
 
     // Now check every path from the entry block to the load for transparency.
     // To do this, we perform a depth first search on the inverse CFG from the
     // loading block.
-    for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++PI) {
-      BasicBlock *P = *PI;
-      for (idf_ext_iterator<BasicBlock*, SmallPtrSet<BasicBlock*, 16> >
-             I = idf_ext_begin(P, TranspBlocks),
-             E = idf_ext_end(P, TranspBlocks); I != E; ++I)
-        if (AA.canBasicBlockModify(**I, Arg, LoadSize))
+    for (BasicBlock *P : predecessors(BB)) {
+      for (BasicBlock *TranspBB : inverse_depth_first_ext(P, TranspBlocks))
+        if (AA.canBasicBlockModify(*TranspBB, Loc))
           return false;
     }
   }
@@ -477,15 +576,15 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, bool isByVal) const {
 /// arguments, and returns the new function.  At this point, we know that it's
 /// safe to do so.
 CallGraphNode *ArgPromotion::DoPromotion(Function *F,
-                               SmallPtrSet<Argument*, 8> &ArgsToPromote,
-                              SmallPtrSet<Argument*, 8> &ByValArgsToTransform) {
+                             SmallPtrSetImpl<Argument*> &ArgsToPromote,
+                             SmallPtrSetImpl<Argument*> &ByValArgsToTransform) {
 
   // Start by computing a new prototype for the function, which is the same as
   // the old function, but has modified arguments.
-  const FunctionType *FTy = F->getFunctionType();
-  std::vector<const Type*> Params;
+  FunctionType *FTy = F->getFunctionType();
+  std::vector<Type*> Params;
 
-  typedef std::set<IndicesVector> ScalarizeTable;
+  typedef std::set<std::pair<Type*, IndicesVector>> ScalarizeTable;
 
   // ScalarizedElements - If we are promoting a pointer that has elements
   // accessed out of it, keep track of which elements are accessed so that we
@@ -499,17 +598,20 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   // OriginalLoads - Keep track of a representative load instruction from the
   // original function so that we can tell the alias analysis implementation
   // what the new GEP/Load instructions we are inserting look like.
-  std::map<IndicesVector, LoadInst*> OriginalLoads;
+  // We need to keep the original loads for each argument and the elements
+  // of the argument that are accessed.
+  std::map<std::pair<Argument*, IndicesVector>, LoadInst*> OriginalLoads;
 
-  // Attributes - Keep track of the parameter attributes for the arguments
+  // Attribute - Keep track of the parameter attributes for the arguments
   // that we are *not* promoting. For the ones that we do promote, the parameter
   // attributes are lost
-  SmallVector<AttributeWithIndex, 8> AttributesVec;
-  const AttrListPtr &PAL = F->getAttributes();
+  SmallVector<AttributeSet, 8> AttributesVec;
+  const AttributeSet &PAL = F->getAttributes();
 
   // Add any return attributes.
-  if (Attributes attrs = PAL.getRetAttributes())
-    AttributesVec.push_back(AttributeWithIndex::get(0, attrs));
+  if (PAL.hasAttributes(AttributeSet::ReturnIndex))
+    AttributesVec.push_back(AttributeSet::get(F->getContext(),
+                                              PAL.getRetAttributes()));
 
   // First, determine the new argument list
   unsigned ArgIndex = 1;
@@ -517,16 +619,19 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
        ++I, ++ArgIndex) {
     if (ByValArgsToTransform.count(I)) {
       // Simple byval argument? Just add all the struct element types.
-      const Type *AgTy = cast<PointerType>(I->getType())->getElementType();
-      const StructType *STy = cast<StructType>(AgTy);
-      for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
-        Params.push_back(STy->getElementType(i));
+      Type *AgTy = cast<PointerType>(I->getType())->getElementType();
+      StructType *STy = cast<StructType>(AgTy);
+      Params.insert(Params.end(), STy->element_begin(), STy->element_end());
       ++NumByValArgsPromoted;
     } else if (!ArgsToPromote.count(I)) {
       // Unchanged argument
       Params.push_back(I->getType());
-      if (Attributes attrs = PAL.getParamAttributes(ArgIndex))
-        AttributesVec.push_back(AttributeWithIndex::get(Params.size(), attrs));
+      AttributeSet attrs = PAL.getParamAttributes(ArgIndex);
+      if (attrs.hasAttributes(ArgIndex)) {
+        AttrBuilder B(attrs, ArgIndex);
+        AttributesVec.
+          push_back(AttributeSet::get(F->getContext(), Params.size(), B));
+      }
     } else if (I->use_empty()) {
       // Dead argument (which are always marked as promotable)
       ++NumArgumentsDead;
@@ -537,42 +642,43 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
       // In this table, we will track which indices are loaded from the argument
       // (where direct loads are tracked as no indices).
       ScalarizeTable &ArgIndices = ScalarizedElements[I];
-      for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
-           ++UI) {
-        Instruction *User = cast<Instruction>(*UI);
-        assert(isa<LoadInst>(User) || isa<GetElementPtrInst>(User));
+      for (User *U : I->users()) {
+        Instruction *UI = cast<Instruction>(U);
+        Type *SrcTy;
+        if (LoadInst *L = dyn_cast<LoadInst>(UI))
+          SrcTy = L->getType();
+        else
+          SrcTy = cast<GetElementPtrInst>(UI)->getSourceElementType();
         IndicesVector Indices;
-        Indices.reserve(User->getNumOperands() - 1);
+        Indices.reserve(UI->getNumOperands() - 1);
         // Since loads will only have a single operand, and GEPs only a single
         // non-index operand, this will record direct loads without any indices,
         // and gep+loads with the GEP indices.
-        for (User::op_iterator II = User->op_begin() + 1, IE = User->op_end();
+        for (User::op_iterator II = UI->op_begin() + 1, IE = UI->op_end();
              II != IE; ++II)
           Indices.push_back(cast<ConstantInt>(*II)->getSExtValue());
         // GEPs with a single 0 index can be merged with direct loads
         if (Indices.size() == 1 && Indices.front() == 0)
           Indices.clear();
-        ArgIndices.insert(Indices);
+        ArgIndices.insert(std::make_pair(SrcTy, Indices));
         LoadInst *OrigLoad;
-        if (LoadInst *L = dyn_cast<LoadInst>(User))
+        if (LoadInst *L = dyn_cast<LoadInst>(UI))
           OrigLoad = L;
         else
           // Take any load, we will use it only to update Alias Analysis
-          OrigLoad = cast<LoadInst>(User->use_back());
-        OriginalLoads[Indices] = OrigLoad;
+          OrigLoad = cast<LoadInst>(UI->user_back());
+        OriginalLoads[std::make_pair(I, Indices)] = OrigLoad;
       }
 
       // Add a parameter to the function for each element passed in.
       for (ScalarizeTable::iterator SI = ArgIndices.begin(),
              E = ArgIndices.end(); SI != E; ++SI) {
         // not allowed to dereference ->begin() if size() is 0
-        Params.push_back(GetElementPtrInst::getIndexedType(I->getType(),
-                                                           SI->begin(),
-                                                           SI->end()));
+        Params.push_back(GetElementPtrInst::getIndexedType(I->getType(), SI->second));
         assert(Params.back());
       }
 
-      if (ArgIndices.size() == 1 && ArgIndices.begin()->empty())
+      if (ArgIndices.size() == 1 && ArgIndices.begin()->second.empty())
         ++NumArgumentsPromoted;
       else
         ++NumAggregatesPromoted;
@@ -580,18 +686,11 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   }
 
   // Add any function attributes.
-  if (Attributes attrs = PAL.getFnAttributes())
-    AttributesVec.push_back(AttributeWithIndex::get(~0, attrs));
+  if (PAL.hasAttributes(AttributeSet::FunctionIndex))
+    AttributesVec.push_back(AttributeSet::get(FTy->getContext(),
+                                              PAL.getFnAttributes()));
 
-  const Type *RetTy = FTy->getReturnType();
-
-  // Work around LLVM bug PR56: the CWriter cannot emit varargs functions which
-  // have zero fixed arguments.
-  bool ExtraArgHack = false;
-  if (Params.empty() && FTy->isVarArg()) {
-    ExtraArgHack = true;
-    Params.push_back(Type::getInt32Ty(F->getContext()));
-  }
+  Type *RetTy = FTy->getReturnType();
 
   // Construct the new function type using the new arguments.
   FunctionType *NFTy = FunctionType::get(RetTy, Params, FTy->isVarArg());
@@ -600,14 +699,23 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   Function *NF = Function::Create(NFTy, F->getLinkage(), F->getName());
   NF->copyAttributesFrom(F);
 
-  
+  // Patch the pointer to LLVM function in debug info descriptor.
+  auto DI = FunctionDIs.find(F);
+  if (DI != FunctionDIs.end()) {
+    DISubprogram SP = DI->second;
+    SP.replaceFunction(NF);
+    // Ensure the map is updated so it can be reused on subsequent argument
+    // promotions of the same function.
+    FunctionDIs.erase(DI);
+    FunctionDIs[NF] = SP;
+  }
+
   DEBUG(dbgs() << "ARG PROMOTION:  Promoting to:" << *NF << "\n"
         << "From: " << *F);
   
   // Recompute the parameter attributes list based on the new arguments for
   // the function.
-  NF->setAttributes(AttrListPtr::get(AttributesVec.begin(),
-                                     AttributesVec.end()));
+  NF->setAttributes(AttributeSet::get(F->getContext(), AttributesVec));
   AttributesVec.clear();
 
   F->getParent()->getFunctionList().insert(F, NF);
@@ -619,8 +727,8 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
 
   // Get the callgraph information that we need to update to reflect our
   // changes.
-  CallGraph &CG = getAnalysis<CallGraph>();
-  
+  CallGraph &CG = getAnalysis<CallGraphWrapperPass>().getCallGraph();
+
   // Get a new callgraph node for NF.
   CallGraphNode *NF_CGN = CG.getOrInsertFunction(NF);
 
@@ -629,14 +737,15 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   //
   SmallVector<Value*, 16> Args;
   while (!F->use_empty()) {
-    CallSite CS(F->use_back());
+    CallSite CS(F->user_back());
     assert(CS.getCalledFunction() == F);
     Instruction *Call = CS.getInstruction();
-    const AttrListPtr &CallPAL = CS.getAttributes();
+    const AttributeSet &CallPAL = CS.getAttributes();
 
     // Add any return attributes.
-    if (Attributes attrs = CallPAL.getRetAttributes())
-      AttributesVec.push_back(AttributeWithIndex::get(0, attrs));
+    if (CallPAL.hasAttributes(AttributeSet::ReturnIndex))
+      AttributesVec.push_back(AttributeSet::get(F->getContext(),
+                                                CallPAL.getRetAttributes()));
 
     // Loop over the operands, inserting GEP and loads in the caller as
     // appropriate.
@@ -647,20 +756,21 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
       if (!ArgsToPromote.count(I) && !ByValArgsToTransform.count(I)) {
         Args.push_back(*AI);          // Unmodified argument
 
-        if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex))
-          AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
-
+        if (CallPAL.hasAttributes(ArgIndex)) {
+          AttrBuilder B(CallPAL, ArgIndex);
+          AttributesVec.
+            push_back(AttributeSet::get(F->getContext(), Args.size(), B));
+        }
       } else if (ByValArgsToTransform.count(I)) {
         // Emit a GEP and load for each element of the struct.
-        const Type *AgTy = cast<PointerType>(I->getType())->getElementType();
-        const StructType *STy = cast<StructType>(AgTy);
+        Type *AgTy = cast<PointerType>(I->getType())->getElementType();
+        StructType *STy = cast<StructType>(AgTy);
         Value *Idxs[2] = {
-              ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 };
+              ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), nullptr };
         for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
           Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i);
-          Value *Idx = GetElementPtrInst::Create(*AI, Idxs, Idxs+2,
-                                                 (*AI)->getName()+"."+utostr(i),
-                                                 Call);
+          Value *Idx = GetElementPtrInst::Create(
+              STy, *AI, Idxs, (*AI)->getName() + "." + utostr(i), Call);
           // TODO: Tell AA about the new values?
           Args.push_back(new LoadInst(Idx, Idx->getName()+".val", Call));
         }
@@ -673,15 +783,15 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         for (ScalarizeTable::iterator SI = ArgIndices.begin(),
                E = ArgIndices.end(); SI != E; ++SI) {
           Value *V = *AI;
-          LoadInst *OrigLoad = OriginalLoads[*SI];
-          if (!SI->empty()) {
-            Ops.reserve(SI->size());
-            const Type *ElTy = V->getType();
-            for (IndicesVector::const_iterator II = SI->begin(),
-                 IE = SI->end(); II != IE; ++II) {
+          LoadInst *OrigLoad = OriginalLoads[std::make_pair(I, SI->second)];
+          if (!SI->second.empty()) {
+            Ops.reserve(SI->second.size());
+            Type *ElTy = V->getType();
+            for (IndicesVector::const_iterator II = SI->second.begin(),
+                 IE = SI->second.end(); II != IE; ++II) {
               // Use i32 to index structs, and i64 for others (pointers/arrays).
               // This satisfies GEP constraints.
-              const Type *IdxTy = (ElTy->isStructTy() ?
+              Type *IdxTy = (ElTy->isStructTy() ?
                     Type::getInt32Ty(F->getContext()) : 
                     Type::getInt64Ty(F->getContext()));
               Ops.push_back(ConstantInt::get(IdxTy, *II));
@@ -689,8 +799,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
               ElTy = cast<CompositeType>(ElTy)->getTypeAtIndex(*II);
             }
             // And create a GEP to extract those indices.
-            V = GetElementPtrInst::Create(V, Ops.begin(), Ops.end(),
-                                          V->getName()+".idx", Call);
+            V = GetElementPtrInst::Create(SI->first, V, Ops, V->getName()+".idx", Call);
             Ops.clear();
             AA.copyValue(OrigLoad->getOperand(0), V);
           }
@@ -698,40 +807,47 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
           // of the previous load.
           LoadInst *newLoad = new LoadInst(V, V->getName()+".val", Call);
           newLoad->setAlignment(OrigLoad->getAlignment());
+          // Transfer the AA info too.
+          AAMDNodes AAInfo;
+          OrigLoad->getAAMetadata(AAInfo);
+          newLoad->setAAMetadata(AAInfo);
+
           Args.push_back(newLoad);
           AA.copyValue(OrigLoad, Args.back());
         }
       }
 
-    if (ExtraArgHack)
-      Args.push_back(Constant::getNullValue(Type::getInt32Ty(F->getContext())));
-
     // Push any varargs arguments on the list.
     for (; AI != CS.arg_end(); ++AI, ++ArgIndex) {
       Args.push_back(*AI);
-      if (Attributes Attrs = CallPAL.getParamAttributes(ArgIndex))
-        AttributesVec.push_back(AttributeWithIndex::get(Args.size(), Attrs));
+      if (CallPAL.hasAttributes(ArgIndex)) {
+        AttrBuilder B(CallPAL, ArgIndex);
+        AttributesVec.
+          push_back(AttributeSet::get(F->getContext(), Args.size(), B));
+      }
     }
 
     // Add any function attributes.
-    if (Attributes attrs = CallPAL.getFnAttributes())
-      AttributesVec.push_back(AttributeWithIndex::get(~0, attrs));
+    if (CallPAL.hasAttributes(AttributeSet::FunctionIndex))
+      AttributesVec.push_back(AttributeSet::get(Call->getContext(),
+                                                CallPAL.getFnAttributes()));
 
     Instruction *New;
     if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
       New = InvokeInst::Create(NF, II->getNormalDest(), II->getUnwindDest(),
-                               Args.begin(), Args.end(), "", Call);
+                               Args, "", Call);
       cast<InvokeInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<InvokeInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
-                                                          AttributesVec.end()));
+      cast<InvokeInst>(New)->setAttributes(AttributeSet::get(II->getContext(),
+                                                            AttributesVec));
     } else {
-      New = CallInst::Create(NF, Args.begin(), Args.end(), "", Call);
+      New = CallInst::Create(NF, Args, "", Call);
       cast<CallInst>(New)->setCallingConv(CS.getCallingConv());
-      cast<CallInst>(New)->setAttributes(AttrListPtr::get(AttributesVec.begin(),
-                                                        AttributesVec.end()));
+      cast<CallInst>(New)->setAttributes(AttributeSet::get(New->getContext(),
+                                                          AttributesVec));
       if (cast<CallInst>(Call)->isTailCall())
         cast<CallInst>(New)->setTailCall();
     }
+    New->setDebugLoc(Call->getDebugLoc());
     Args.clear();
     AttributesVec.clear();
 
@@ -758,8 +874,8 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   // function empty.
   NF->getBasicBlockList().splice(NF->begin(), F->getBasicBlockList());
 
-  // Loop over the argument list, transfering uses of the old arguments over to
-  // the new arguments, also transfering over the names as well.
+  // Loop over the argument list, transferring uses of the old arguments over to
+  // the new arguments, also transferring over the names as well.
   //
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(),
        I2 = NF->arg_begin(); I != E; ++I) {
@@ -779,18 +895,17 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
       Instruction *InsertPt = NF->begin()->begin();
 
       // Just add all the struct element types.
-      const Type *AgTy = cast<PointerType>(I->getType())->getElementType();
-      Value *TheAlloca = new AllocaInst(AgTy, 0, "", InsertPt);
-      const StructType *STy = cast<StructType>(AgTy);
+      Type *AgTy = cast<PointerType>(I->getType())->getElementType();
+      Value *TheAlloca = new AllocaInst(AgTy, nullptr, "", InsertPt);
+      StructType *STy = cast<StructType>(AgTy);
       Value *Idxs[2] = {
-            ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), 0 };
+            ConstantInt::get(Type::getInt32Ty(F->getContext()), 0), nullptr };
 
       for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
         Idxs[1] = ConstantInt::get(Type::getInt32Ty(F->getContext()), i);
-        Value *Idx = 
-          GetElementPtrInst::Create(TheAlloca, Idxs, Idxs+2,
-                                    TheAlloca->getName()+"."+Twine(i), 
-                                    InsertPt);
+        Value *Idx = GetElementPtrInst::Create(
+            AgTy, TheAlloca, Idxs, TheAlloca->getName() + "." + Twine(i),
+            InsertPt);
         I2->setName(I->getName()+"."+Twine(i));
         new StoreInst(I2++, Idx, InsertPt);
       }
@@ -799,6 +914,15 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
       I->replaceAllUsesWith(TheAlloca);
       TheAlloca->takeName(I);
       AA.replaceWithNewValue(I, TheAlloca);
+
+      // If the alloca is used in a call, we must clear the tail flag since
+      // the callee now uses an alloca from the caller.
+      for (User *U : TheAlloca->users()) {
+        CallInst *Call = dyn_cast<CallInst>(U);
+        if (!Call)
+          continue;
+        Call->setTailCall(false);
+      }
       continue;
     }
 
@@ -813,8 +937,8 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
     ScalarizeTable &ArgIndices = ScalarizedElements[I];
 
     while (!I->use_empty()) {
-      if (LoadInst *LI = dyn_cast<LoadInst>(I->use_back())) {
-        assert(ArgIndices.begin()->empty() &&
+      if (LoadInst *LI = dyn_cast<LoadInst>(I->user_back())) {
+        assert(ArgIndices.begin()->second.empty() &&
                "Load element should sort to front!");
         I2->setName(I->getName()+".val");
         LI->replaceAllUsesWith(I2);
@@ -823,7 +947,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         DEBUG(dbgs() << "*** Promoted load of argument '" << I->getName()
               << "' in function '" << F->getName() << "'\n");
       } else {
-        GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->use_back());
+        GetElementPtrInst *GEP = cast<GetElementPtrInst>(I->user_back());
         IndicesVector Operands;
         Operands.reserve(GEP->getNumIndices());
         for (User::op_iterator II = GEP->idx_begin(), IE = GEP->idx_end();
@@ -836,7 +960,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
 
         Function::arg_iterator TheArg = I2;
         for (ScalarizeTable::iterator It = ArgIndices.begin();
-             *It != Operands; ++It, ++TheArg) {
+             It->second != Operands; ++It, ++TheArg) {
           assert(It != ArgIndices.end() && "GEP not handled??");
         }
 
@@ -853,7 +977,7 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
         // All of the uses must be load instructions.  Replace them all with
         // the argument specified by ArgNo.
         while (!GEP->use_empty()) {
-          LoadInst *L = cast<LoadInst>(GEP->use_back());
+          LoadInst *L = cast<LoadInst>(GEP->user_back());
           L->replaceAllUsesWith(TheArg);
           AA.replaceWithNewValue(L, TheArg);
           L->eraseFromParent();
@@ -864,16 +988,9 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
     }
 
     // Increment I2 past all of the arguments added for this promoted pointer.
-    for (unsigned i = 0, e = ArgIndices.size(); i != e; ++i)
-      ++I2;
+    std::advance(I2, ArgIndices.size());
   }
 
-  // Notify the alias analysis implementation that we inserted a new argument.
-  if (ExtraArgHack)
-    AA.copyValue(Constant::getNullValue(Type::getInt32Ty(F->getContext())), 
-                 NF->arg_begin());
-
-
   // Tell the alias analysis that the old function is about to disappear.
   AA.replaceWithNewValue(F, NF);
 
@@ -891,3 +1008,8 @@ CallGraphNode *ArgPromotion::DoPromotion(Function *F,
   
   return NF_CGN;
 }
+
+bool ArgPromotion::doInitialization(CallGraph &CG) {
+  FunctionDIs = makeSubprogramMap(CG.getModule());
+  return CallGraphSCCPass::doInitialization(CG);
+}