DataLayout is mandatory, update the API to reflect it with references.

Summary:
Now that the DataLayout is a mandatory part of the module, let's start
cleaning the codebase. This patch is a first attempt at doing that.

This patch is not exactly NFC as for instance some places were passing
a nullptr instead of the DataLayout, possibly just because there was a
default value on the DataLayout argument to many functions in the API.
Even though it is not purely NFC, there is no change in the
validation.

I turned as many pointer to DataLayout to references, this helped
figuring out all the places where a nullptr could come up.

I had initially a local version of this patch broken into over 30
independant, commits but some later commit were cleaning the API and
touching part of the code modified in the previous commits, so it
seemed cleaner without the intermediate state.

Test Plan:

Reviewers: echristo

Subscribers: llvm-commits

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 231740

5 files changed, 63 insertions, 85 deletions

diff --git a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
index 52cca0f2a2e..a0687738b16 100644
--- a/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/ArgumentPromotion.cpp
@@ -69,16 +69,15 @@ namespace {
     bool runOnSCC(CallGraphSCC &SCC) override;
     static char ID; // Pass identification, replacement for typeid
     explicit ArgPromotion(unsigned maxElements = 3)
-        : CallGraphSCCPass(ID), DL(nullptr), 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;
 
-    const DataLayout *DL;
   private:
-    bool isDenselyPacked(Type *type);
+    bool isDenselyPacked(Type *type, const DataLayout &DL);
     bool canPaddingBeAccessed(Argument *Arg);
     CallGraphNode *PromoteArguments(CallGraphNode *CGN);
     bool isSafeToPromoteArgument(Argument *Arg, bool isByVal) const;
@@ -125,7 +124,7 @@ bool ArgPromotion::runOnSCC(CallGraphSCC &SCC) {
 }
 
 /// \brief Checks if a type could have padding bytes.
-bool ArgPromotion::isDenselyPacked(Type *type) {
+bool ArgPromotion::isDenselyPacked(Type *type, const DataLayout &DL) {
 
   // There is no size information, so be conservative.
   if (!type->isSized())
@@ -133,7 +132,7 @@ bool ArgPromotion::isDenselyPacked(Type *type) {
 
   // 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 || DL->getTypeSizeInBits(type) != DL->getTypeAllocSizeInBits(type))
+  if (DL.getTypeSizeInBits(type) != DL.getTypeAllocSizeInBits(type))
     return false;
 
   if (!isa<CompositeType>(type))
@@ -141,19 +140,20 @@ bool ArgPromotion::isDenselyPacked(Type *type) {
 
   // For homogenous sequential types, check for padding within members.
   if (SequentialType *seqTy = dyn_cast<SequentialType>(type))
-    return isa<PointerType>(seqTy) || isDenselyPacked(seqTy->getElementType());
+    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);
+  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))
+    if (!isDenselyPacked(ElTy, DL))
       return false;
     if (StartPos != Layout->getElementOffsetInBits(i))
       return false;
-    StartPos += DL->getTypeAllocSizeInBits(ElTy);
+    StartPos += DL.getTypeAllocSizeInBits(ElTy);
   }
 
   return true;
@@ -207,8 +207,6 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
   // Make sure that it is local to this module.
   if (!F || !F->hasLocalLinkage()) return nullptr;
 
-  DL = &F->getParent()->getDataLayout();
-
   // First check: see if there are any pointer arguments!  If not, quick exit.
   SmallVector<Argument*, 16> PointerArgs;
   for (Function::arg_iterator I = F->arg_begin(), E = F->arg_end(); I != E; ++I)
@@ -235,6 +233,7 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
   // 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.
@@ -249,8 +248,8 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
     // packed or if we can prove the padding bytes are never accessed. This does
     // not apply to inalloca.
     bool isSafeToPromote =
-      PtrArg->hasByValAttr() &&
-      (isDenselyPacked(AgTy) || !canPaddingBeAccessed(PtrArg));
+        PtrArg->hasByValAttr() &&
+        (isDenselyPacked(AgTy, DL) || !canPaddingBeAccessed(PtrArg));
     if (isSafeToPromote) {
       if (StructType *STy = dyn_cast<StructType>(AgTy)) {
         if (maxElements > 0 && STy->getNumElements() > maxElements) {
@@ -309,9 +308,9 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) {
 
 /// AllCallersPassInValidPointerForArgument - Return true if we can prove that
 /// all callees pass in a valid pointer for the specified function argument.
-static bool AllCallersPassInValidPointerForArgument(Argument *Arg,
-                                                    const DataLayout *DL) {
+static bool AllCallersPassInValidPointerForArgument(Argument *Arg) {
   Function *Callee = Arg->getParent();
+  const DataLayout &DL = Callee->getParent()->getDataLayout();
 
   unsigned ArgNo = Arg->getArgNo();
 
@@ -429,7 +428,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg,
   GEPIndicesSet ToPromote;
 
   // If the pointer is always valid, any load with first index 0 is valid.
-  if (isByValOrInAlloca || AllCallersPassInValidPointerForArgument(Arg, DL))
+  if (isByValOrInAlloca || AllCallersPassInValidPointerForArgument(Arg))
     SafeToUnconditionallyLoad.insert(IndicesVector(1, 0));
 
   // First, iterate the entry block and mark loads of (geps of) arguments as
diff --git a/llvm/lib/Transforms/IPO/ConstantMerge.cpp b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
index 98077af2f54..8ce7646621f 100644
--- a/llvm/lib/Transforms/IPO/ConstantMerge.cpp
+++ b/llvm/lib/Transforms/IPO/ConstantMerge.cpp
@@ -52,7 +52,6 @@ namespace {
     // alignment to a concrete value.
     unsigned getAlignment(GlobalVariable *GV) const;
 
-    const DataLayout *DL;
   };
 }
 
@@ -89,31 +88,22 @@ static bool IsBetterCanonical(const GlobalVariable &A,
   return A.hasUnnamedAddr();
 }
 
-bool ConstantMerge::hasKnownAlignment(GlobalVariable *GV) const {
-  return DL || GV->getAlignment() != 0;
-}
-
 unsigned ConstantMerge::getAlignment(GlobalVariable *GV) const {
   unsigned Align = GV->getAlignment();
   if (Align)
     return Align;
-  if (DL)
-    return DL->getPreferredAlignment(GV);
-  return 0;
+  return GV->getParent()->getDataLayout().getPreferredAlignment(GV);
 }
 
 bool ConstantMerge::runOnModule(Module &M) {
-  DL = &M.getDataLayout();
 
   // Find all the globals that are marked "used".  These cannot be merged.
   SmallPtrSet<const GlobalValue*, 8> UsedGlobals;
   FindUsedValues(M.getGlobalVariable("llvm.used"), UsedGlobals);
   FindUsedValues(M.getGlobalVariable("llvm.compiler.used"), UsedGlobals);
-  
-  // Map unique <constants, has-unknown-alignment> pairs to globals.  We don't
-  // want to merge globals of unknown alignment with those of explicit
-  // alignment.  If we have DataLayout, we always know the alignment.
-  DenseMap<PointerIntPair<Constant*, 1, bool>, GlobalVariable*> CMap;
+
+  // Map unique constants to globals.
+  DenseMap<Constant *, GlobalVariable *> CMap;
 
   // Replacements - This vector contains a list of replacements to perform.
   SmallVector<std::pair<GlobalVariable*, GlobalVariable*>, 32> Replacements;
@@ -155,8 +145,7 @@ bool ConstantMerge::runOnModule(Module &M) {
       Constant *Init = GV->getInitializer();
 
       // Check to see if the initializer is already known.
-      PointerIntPair<Constant*, 1, bool> Pair(Init, hasKnownAlignment(GV));
-      GlobalVariable *&Slot = CMap[Pair];
+      GlobalVariable *&Slot = CMap[Init];
 
       // If this is the first constant we find or if the old one is local,
       // replace with the current one. If the current is externally visible
@@ -187,8 +176,7 @@ bool ConstantMerge::runOnModule(Module &M) {
       Constant *Init = GV->getInitializer();
 
       // Check to see if the initializer is already known.
-      PointerIntPair<Constant*, 1, bool> Pair(Init, hasKnownAlignment(GV));
-      GlobalVariable *Slot = CMap[Pair];
+      GlobalVariable *Slot = CMap[Init];
 
       if (!Slot || Slot == GV)
         continue;
diff --git a/llvm/lib/Transforms/IPO/GlobalOpt.cpp b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
index 8f6f999e393..c62eeec41f8 100644
--- a/llvm/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/llvm/lib/Transforms/IPO/GlobalOpt.cpp
@@ -86,7 +86,6 @@ namespace {
                                const GlobalStatus &GS);
     bool OptimizeEmptyGlobalCXXDtors(Function *CXAAtExitFn);
 
-    //    const DataLayout *DL;
     TargetLibraryInfo *TLI;
     SmallSet<const Comdat *, 8> NotDiscardableComdats;
   };
@@ -319,7 +318,7 @@ static bool CleanupConstantGlobalUsers(Value *V, Constant *Init,
       Constant *SubInit = nullptr;
       if (!isa<ConstantExpr>(GEP->getOperand(0))) {
         ConstantExpr *CE = dyn_cast_or_null<ConstantExpr>(
-            ConstantFoldInstruction(GEP, &DL, TLI));
+            ConstantFoldInstruction(GEP, DL, TLI));
         if (Init && CE && CE->getOpcode() == Instruction::GetElementPtr)
           SubInit = ConstantFoldLoadThroughGEPConstantExpr(Init, CE);
 
@@ -806,7 +805,7 @@ static void ConstantPropUsersOf(Value *V, const DataLayout &DL,
                                 TargetLibraryInfo *TLI) {
   for (Value::user_iterator UI = V->user_begin(), E = V->user_end(); UI != E; )
     if (Instruction *I = dyn_cast<Instruction>(*UI++))
-      if (Constant *NewC = ConstantFoldInstruction(I, &DL, TLI)) {
+      if (Constant *NewC = ConstantFoldInstruction(I, DL, TLI)) {
         I->replaceAllUsesWith(NewC);
 
         // Advance UI to the next non-I use to avoid invalidating it!
@@ -1490,7 +1489,7 @@ static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV, CallInst *CI,
   // This eliminates dynamic allocation, avoids an indirection accessing the
   // data, and exposes the resultant global to further GlobalOpt.
   // We cannot optimize the malloc if we cannot determine malloc array size.
-  Value *NElems = getMallocArraySize(CI, &DL, TLI, true);
+  Value *NElems = getMallocArraySize(CI, DL, TLI, true);
   if (!NElems)
     return false;
 
@@ -1544,7 +1543,7 @@ static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV, CallInst *CI,
         CI = cast<CallInst>(Malloc);
     }
 
-    GVI = PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, &DL, TLI, true),
+    GVI = PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, DL, TLI, true),
                                DL, TLI);
     return true;
   }
@@ -1948,7 +1947,7 @@ bool GlobalOpt::OptimizeGlobalVars(Module &M) {
     if (GV->hasInitializer())
       if (ConstantExpr *CE = dyn_cast<ConstantExpr>(GV->getInitializer())) {
         auto &DL = M.getDataLayout();
-        Constant *New = ConstantFoldConstantExpression(CE, &DL, TLI);
+        Constant *New = ConstantFoldConstantExpression(CE, DL, TLI);
         if (New && New != CE)
           GV->setInitializer(New);
       }
@@ -2296,7 +2295,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
       Constant *Ptr = getVal(SI->getOperand(1));
       if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
         DEBUG(dbgs() << "Folding constant ptr expression: " << *Ptr);
-        Ptr = ConstantFoldConstantExpression(CE, &DL, TLI);
+        Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
         DEBUG(dbgs() << "; To: " << *Ptr << "\n");
       }
       if (!isSimpleEnoughPointerToCommit(Ptr)) {
@@ -2341,7 +2340,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
 
               Ptr = ConstantExpr::getGetElementPtr(Ptr, IdxList);
               if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr))
-                Ptr = ConstantFoldConstantExpression(CE, &DL, TLI);
+                Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
 
             // If we can't improve the situation by introspecting NewTy,
             // we have to give up.
@@ -2416,7 +2415,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
 
       Constant *Ptr = getVal(LI->getOperand(0));
       if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Ptr)) {
-        Ptr = ConstantFoldConstantExpression(CE, &DL, TLI);
+        Ptr = ConstantFoldConstantExpression(CE, DL, TLI);
         DEBUG(dbgs() << "Found a constant pointer expression, constant "
               "folding: " << *Ptr << "\n");
       }
@@ -2600,7 +2599,7 @@ bool Evaluator::EvaluateBlock(BasicBlock::iterator CurInst,
 
     if (!CurInst->use_empty()) {
       if (ConstantExpr *CE = dyn_cast<ConstantExpr>(InstResult))
-        InstResult = ConstantFoldConstantExpression(CE, &DL, TLI);
+        InstResult = ConstantFoldConstantExpression(CE, DL, TLI);
 
       setVal(CurInst, InstResult);
     }
diff --git a/llvm/lib/Transforms/IPO/LowerBitSets.cpp b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
index 85a2ced85c5..9eb5cdba0e5 100644
--- a/llvm/lib/Transforms/IPO/LowerBitSets.cpp
+++ b/llvm/lib/Transforms/IPO/LowerBitSets.cpp
@@ -52,7 +52,7 @@ bool BitSetInfo::containsGlobalOffset(uint64_t Offset) const {
 }
 
 bool BitSetInfo::containsValue(
-    const DataLayout *DL,
+    const DataLayout &DL,
     const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout, Value *V,
     uint64_t COffset) const {
   if (auto GV = dyn_cast<GlobalVariable>(V)) {
@@ -63,8 +63,8 @@ bool BitSetInfo::containsValue(
   }
 
   if (auto GEP = dyn_cast<GEPOperator>(V)) {
-    APInt APOffset(DL->getPointerSizeInBits(0), 0);
-    bool Result = GEP->accumulateConstantOffset(*DL, APOffset);
+    APInt APOffset(DL.getPointerSizeInBits(0), 0);
+    bool Result = GEP->accumulateConstantOffset(DL, APOffset);
     if (!Result)
       return false;
     COffset += APOffset.getZExtValue();
@@ -186,7 +186,6 @@ struct LowerBitSets : public ModulePass {
 
   Module *M;
 
-  const DataLayout *DL;
   IntegerType *Int1Ty;
   IntegerType *Int8Ty;
   IntegerType *Int32Ty;
@@ -234,14 +233,14 @@ ModulePass *llvm::createLowerBitSetsPass() { return new LowerBitSets; }
 
 bool LowerBitSets::doInitialization(Module &Mod) {
   M = &Mod;
-  DL = &Mod.getDataLayout();
+  const DataLayout &DL = Mod.getDataLayout();
 
   Int1Ty = Type::getInt1Ty(M->getContext());
   Int8Ty = Type::getInt8Ty(M->getContext());
   Int32Ty = Type::getInt32Ty(M->getContext());
   Int32PtrTy = PointerType::getUnqual(Int32Ty);
   Int64Ty = Type::getInt64Ty(M->getContext());
-  IntPtrTy = DL->getIntPtrType(M->getContext(), 0);
+  IntPtrTy = DL.getIntPtrType(M->getContext(), 0);
 
   BitSetNM = M->getNamedMetadata("llvm.bitsets");
 
@@ -396,6 +395,7 @@ Value *LowerBitSets::lowerBitSetCall(
     GlobalVariable *CombinedGlobal,
     const DenseMap<GlobalVariable *, uint64_t> &GlobalLayout) {
   Value *Ptr = CI->getArgOperand(0);
+  const DataLayout &DL = M->getDataLayout();
 
   if (BSI.containsValue(DL, GlobalLayout, Ptr))
     return ConstantInt::getTrue(CombinedGlobal->getParent()->getContext());
@@ -430,8 +430,8 @@ Value *LowerBitSets::lowerBitSetCall(
     Value *OffsetSHR =
         B.CreateLShr(PtrOffset, ConstantInt::get(IntPtrTy, BSI.AlignLog2));
     Value *OffsetSHL = B.CreateShl(
-        PtrOffset, ConstantInt::get(IntPtrTy, DL->getPointerSizeInBits(0) -
-                                                  BSI.AlignLog2));
+        PtrOffset,
+        ConstantInt::get(IntPtrTy, DL.getPointerSizeInBits(0) - BSI.AlignLog2));
     BitOffset = B.CreateOr(OffsetSHR, OffsetSHL);
   }
 
@@ -466,9 +466,10 @@ void LowerBitSets::buildBitSetsFromGlobals(
     const std::vector<GlobalVariable *> &Globals) {
   // Build a new global with the combined contents of the referenced globals.
   std::vector<Constant *> GlobalInits;
+  const DataLayout &DL = M->getDataLayout();
   for (GlobalVariable *G : Globals) {
     GlobalInits.push_back(G->getInitializer());
-    uint64_t InitSize = DL->getTypeAllocSize(G->getInitializer()->getType());
+    uint64_t InitSize = DL.getTypeAllocSize(G->getInitializer()->getType());
 
     // Compute the amount of padding required to align the next element to the
     // next power of 2.
@@ -490,7 +491,7 @@ void LowerBitSets::buildBitSetsFromGlobals(
                          GlobalValue::PrivateLinkage, NewInit);
 
   const StructLayout *CombinedGlobalLayout =
-      DL->getStructLayout(cast<StructType>(NewInit->getType()));
+      DL.getStructLayout(cast<StructType>(NewInit->getType()));
 
   // Compute the offsets of the original globals within the new global.
   DenseMap<GlobalVariable *, uint64_t> GlobalLayout;
diff --git a/llvm/lib/Transforms/IPO/MergeFunctions.cpp b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
index 71c53efb584..596674d6816 100644
--- a/llvm/lib/Transforms/IPO/MergeFunctions.cpp
+++ b/llvm/lib/Transforms/IPO/MergeFunctions.cpp
@@ -127,9 +127,8 @@ namespace {
 /// side of claiming that two functions are different).
 class FunctionComparator {
 public:
-  FunctionComparator(const DataLayout *DL, const Function *F1,
-                     const Function *F2)
-      : FnL(F1), FnR(F2), DL(DL) {}
+  FunctionComparator(const Function *F1, const Function *F2)
+      : FnL(F1), FnR(F2) {}
 
   /// Test whether the two functions have equivalent behaviour.
   int compare();
@@ -292,8 +291,7 @@ private:
   /// Parts to be compared for each comparison stage,
   /// most significant stage first:
   /// 1. Address space. As numbers.
-  /// 2. Constant offset, (if "DataLayout *DL" field is not NULL,
-  /// using GEPOperator::accumulateConstantOffset method).
+  /// 2. Constant offset, (using GEPOperator::accumulateConstantOffset method).
   /// 3. Pointer operand type (using cmpType method).
   /// 4. Number of operands.
   /// 5. Compare operands, using cmpValues method.
@@ -354,8 +352,6 @@ private:
   // The two functions undergoing comparison.
   const Function *FnL, *FnR;
 
-  const DataLayout *DL;
-
   /// Assign serial numbers to values from left function, and values from
   /// right function.
   /// Explanation:
@@ -394,14 +390,13 @@ private:
 
 class FunctionNode {
   AssertingVH<Function> F;
-  const DataLayout *DL;
 
 public:
-  FunctionNode(Function *F, const DataLayout *DL) : F(F), DL(DL) {}
+  FunctionNode(Function *F) : F(F) {}
   Function *getFunc() const { return F; }
   void release() { F = 0; }
   bool operator<(const FunctionNode &RHS) const {
-    return (FunctionComparator(DL, F, RHS.getFunc()).compare()) == -1;
+    return (FunctionComparator(F, RHS.getFunc()).compare()) == -1;
   }
 };
 }
@@ -620,10 +615,11 @@ int FunctionComparator::cmpTypes(Type *TyL, Type *TyR) const {
   PointerType *PTyL = dyn_cast<PointerType>(TyL);
   PointerType *PTyR = dyn_cast<PointerType>(TyR);
 
-  if (DL) {
-    if (PTyL && PTyL->getAddressSpace() == 0) TyL = DL->getIntPtrType(TyL);
-    if (PTyR && PTyR->getAddressSpace() == 0) TyR = DL->getIntPtrType(TyR);
-  }
+  const DataLayout &DL = FnL->getParent()->getDataLayout();
+  if (PTyL && PTyL->getAddressSpace() == 0)
+    TyL = DL.getIntPtrType(TyL);
+  if (PTyR && PTyR->getAddressSpace() == 0)
+    TyR = DL.getIntPtrType(TyR);
 
   if (TyL == TyR)
     return 0;
@@ -855,13 +851,12 @@ int FunctionComparator::cmpGEPs(const GEPOperator *GEPL,
 
   // When we have target data, we can reduce the GEP down to the value in bytes
   // added to the address.
-  if (DL) {
-    unsigned BitWidth = DL->getPointerSizeInBits(ASL);
-    APInt OffsetL(BitWidth, 0), OffsetR(BitWidth, 0);
-    if (GEPL->accumulateConstantOffset(*DL, OffsetL) &&
-        GEPR->accumulateConstantOffset(*DL, OffsetR))
-      return cmpAPInts(OffsetL, OffsetR);
-  }
+  const DataLayout &DL = FnL->getParent()->getDataLayout();
+  unsigned BitWidth = DL.getPointerSizeInBits(ASL);
+  APInt OffsetL(BitWidth, 0), OffsetR(BitWidth, 0);
+  if (GEPL->accumulateConstantOffset(DL, OffsetL) &&
+      GEPR->accumulateConstantOffset(DL, OffsetR))
+    return cmpAPInts(OffsetL, OffsetR);
 
   if (int Res = cmpNumbers((uint64_t)GEPL->getPointerOperand()->getType(),
                            (uint64_t)GEPR->getPointerOperand()->getType()))
@@ -1122,9 +1117,6 @@ private:
   /// to modify it.
   FnTreeType FnTree;
 
-  /// DataLayout for more accurate GEP comparisons. May be NULL.
-  const DataLayout *DL;
-
   /// Whether or not the target supports global aliases.
   bool HasGlobalAliases;
 };
@@ -1152,8 +1144,8 @@ bool MergeFunctions::doSanityCheck(std::vector<WeakVH> &Worklist) {
       for (std::vector<WeakVH>::iterator J = I; J != E && j < Max; ++J, ++j) {
         Function *F1 = cast<Function>(*I);
         Function *F2 = cast<Function>(*J);
-        int Res1 = FunctionComparator(DL, F1, F2).compare();
-        int Res2 = FunctionComparator(DL, F2, F1).compare();
+        int Res1 = FunctionComparator(F1, F2).compare();
+        int Res2 = FunctionComparator(F2, F1).compare();
 
         // If F1 <= F2, then F2 >= F1, otherwise report failure.
         if (Res1 != -Res2) {
@@ -1174,8 +1166,8 @@ bool MergeFunctions::doSanityCheck(std::vector<WeakVH> &Worklist) {
             continue;
 
           Function *F3 = cast<Function>(*K);
-          int Res3 = FunctionComparator(DL, F1, F3).compare();
-          int Res4 = FunctionComparator(DL, F2, F3).compare();
+          int Res3 = FunctionComparator(F1, F3).compare();
+          int Res4 = FunctionComparator(F2, F3).compare();
 
           bool Transitive = true;
 
@@ -1212,7 +1204,6 @@ bool MergeFunctions::doSanityCheck(std::vector<WeakVH> &Worklist) {
 
 bool MergeFunctions::runOnModule(Module &M) {
   bool Changed = false;
-  DL = &M.getDataLayout();
 
   for (Module::iterator I = M.begin(), E = M.end(); I != E; ++I) {
     if (!I->isDeclaration() && !I->hasAvailableExternallyLinkage())
@@ -1419,7 +1410,7 @@ void MergeFunctions::mergeTwoFunctions(Function *F, Function *G) {
 // that was already inserted.
 bool MergeFunctions::insert(Function *NewFunction) {
   std::pair<FnTreeType::iterator, bool> Result =
-      FnTree.insert(FunctionNode(NewFunction, DL));
+      FnTree.insert(FunctionNode(NewFunction));
 
   if (Result.second) {
     DEBUG(dbgs() << "Inserting as unique: " << NewFunction->getName() << '\n');
@@ -1456,7 +1447,7 @@ bool MergeFunctions::insert(Function *NewFunction) {
 void MergeFunctions::remove(Function *F) {
   // We need to make sure we remove F, not a function "equal" to F per the
   // function equality comparator.
-  FnTreeType::iterator found = FnTree.find(FunctionNode(F, DL));
+  FnTreeType::iterator found = FnTree.find(FunctionNode(F));
   size_t Erased = 0;
   if (found != FnTree.end() && found->getFunc() == F) {
     Erased = 1;