[Alignment][NFC] migrate DataLayout::getPreferredAlignment

[gchatelet]

Summary

This patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790

llvm/include/llvm/IR/DataLayout.h

public:
   /// struct, its size, and the offsets of its fields.
   ///
   /// Note that this information is lazily cached.
   const StructLayout *getStructLayout(StructType *Ty) const;
 
   /// Returns the preferred alignment of the specified global.
   ///
   /// This includes an explicitly requested alignment (if the global has one).
-  unsigned getPreferredAlignment(const GlobalVariable *GV) const;
+  Align getPreferredAlign(const GlobalVariable *GV) const;
+
+  /// Returns the preferred alignment of the specified global.
+  ///
+  /// This includes an explicitly requested alignment (if the global has one).
+  LLVM_ATTRIBUTE_DEPRECATED(
+      inline unsigned getPreferredAlignment(const GlobalVariable *GV) const,
+      "Use getPreferredAlign instead") {
+    return getPreferredAlign(GV).value();
+  }
 
   /// Returns the preferred alignment of the specified global, returned
   /// in log form.
   ///
   /// This includes an explicitly requested alignment (if the global has one).
-  unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const;
+  LLVM_ATTRIBUTE_DEPRECATED(
+      inline unsigned getPreferredAlignmentLog(const GlobalVariable *GV) const,
+      "Inline where needed") {
+    return Log2(getPreferredAlign(GV));
+  }
 };
 
 inline DataLayout *unwrap(LLVMTargetDataRef P) {
   return reinterpret_cast<DataLayout *>(P);
 }
 
 inline LLVMTargetDataRef wrap(const DataLayout *P) {
   return reinterpret_cast<LLVMTargetDataRef>(const_cast<DataLayout *>(P));

llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp

 }
 
 /// getGVAlignment - Return the alignment to use for the specified global
 /// value.  This rounds up to the preferred alignment if possible and legal.
 Align AsmPrinter::getGVAlignment(const GlobalObject *GV, const DataLayout &DL,
                                  Align InAlign) {
   Align Alignment;
   if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
-    Alignment = Align(DL.getPreferredAlignment(GVar));
+    Alignment = DL.getPreferredAlign(GVar);
 
   // If InAlign is specified, round it to it.
   if (InAlign > Alignment)
     Alignment = InAlign;
 
   // If the GV has a specified alignment, take it into account.
   const MaybeAlign GVAlign(GV->getAlignment());
   if (!GVAlign)

llvm/lib/CodeGen/GlobalMerge.cpp

while (i != -1) {
     bool HasExternal = false;
     StringRef FirstExternalName;
     Align MaxAlign;
     unsigned CurIdx = 0;
     for (j = i; j != -1; j = GlobalSet.find_next(j)) {
       Type *Ty = Globals[j]->getValueType();
 
       // Make sure we use the same alignment AsmPrinter would use.
-      Align Alignment(DL.getPreferredAlignment(Globals[j]));
+      Align Alignment = DL.getPreferredAlign(Globals[j]);
       unsigned Padding = alignTo(MergedSize, Alignment) - MergedSize;
       MergedSize += Padding;
       MergedSize += DL.getTypeAllocSize(Ty);
       if (MergedSize > MaxOffset) {
         break;
       }
       if (Padding) {
         Tys.push_back(ArrayType::get(Int8Ty, Padding));

llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp

 getELFSectionNameForGlobal(const GlobalObject *GO, SectionKind Kind,
                            Mangler &Mang, const TargetMachine &TM,
                            unsigned EntrySize, bool UniqueSectionName) {
   SmallString<128> Name;
   if (Kind.isMergeableCString()) {
     // We also need alignment here.
     // FIXME: this is getting the alignment of the character, not the
     // alignment of the global!
-    unsigned Align = GO->getParent()->getDataLayout().getPreferredAlignment(
+    Align Alignment = GO->getParent()->getDataLayout().getPreferredAlign(
         cast<GlobalVariable>(GO));
 
     std::string SizeSpec = ".rodata.str" + utostr(EntrySize) + ".";
-    Name = SizeSpec + utostr(Align);
+    Name = SizeSpec + utostr(Alignment.value());
   } else if (Kind.isMergeableConst()) {
     Name = ".rodata.cst";
     Name += utostr(EntrySize);
   } else {
     Name = getSectionPrefixForGlobal(Kind);
   }
 
   bool HasPrefix = false;
if (Kind.isReadOnly())
       return ConstTextCoalSection;
     if (Kind.isReadOnlyWithRel())
       return ConstDataCoalSection;
     return DataCoalSection;
   }
 
   // FIXME: Alignment check should be handled by section classifier.
   if (Kind.isMergeable1ByteCString() &&
-      GO->getParent()->getDataLayout().getPreferredAlignment(
-          cast<GlobalVariable>(GO)) < 32)
+      GO->getParent()->getDataLayout().getPreferredAlign(
+          cast<GlobalVariable>(GO)) < Align(32))
     return CStringSection;
 
   // Do not put 16-bit arrays in the UString section if they have an
   // externally visible label, this runs into issues with certain linker
   // versions.
   if (Kind.isMergeable2ByteCString() && !GO->hasExternalLinkage() &&
-      GO->getParent()->getDataLayout().getPreferredAlignment(
-          cast<GlobalVariable>(GO)) < 32)
+      GO->getParent()->getDataLayout().getPreferredAlign(
+          cast<GlobalVariable>(GO)) < Align(32))
     return UStringSection;
 
   // With MachO only variables whose corresponding symbol starts with 'l' or
   // 'L' can be merged, so we only try merging GVs with private linkage.
   if (GO->hasPrivateLinkage() && Kind.isMergeableConst()) {
     if (Kind.isMergeableConst4())
       return FourByteConstantSection;
     if (Kind.isMergeableConst8())
if (Kind.isBSSLocal() || Kind.isCommon()) {
     XCOFF::StorageClass SC =
         TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO);
     return getContext().getXCOFFSection(
         Name, Kind.isBSSLocal() ? XCOFF::XMC_BS : XCOFF::XMC_RW, XCOFF::XTY_CM,
         SC, Kind, /* BeginSymbolName */ nullptr);
   }
 
   if (Kind.isMergeableCString()) {
-    unsigned Align = GO->getParent()->getDataLayout().getPreferredAlignment(
+    Align Alignment = GO->getParent()->getDataLayout().getPreferredAlign(
         cast<GlobalVariable>(GO));
 
     unsigned EntrySize = getEntrySizeForKind(Kind);
     std::string SizeSpec = ".rodata.str" + utostr(EntrySize) + ".";
     SmallString<128> Name;
-    Name = SizeSpec + utostr(Align);
+    Name = SizeSpec + utostr(Alignment.value());
 
     return getContext().getXCOFFSection(
         Name, XCOFF::XMC_RO, XCOFF::XTY_SD,
         TargetLoweringObjectFileXCOFF::getStorageClassForGlobal(GO),
         Kind, /* BeginSymbolName */ nullptr);
   }
 
   if (Kind.isText())

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

 
 public:
   /// Returns the address the GlobalVariable should be written into.  The
   /// GVMemoryBlock object prefixes that.
   static char *Create(const GlobalVariable *GV, const DataLayout& TD) {
     Type *ElTy = GV->getValueType();
     size_t GVSize = (size_t)TD.getTypeAllocSize(ElTy);
     void *RawMemory = ::operator new(
-        alignTo(sizeof(GVMemoryBlock), TD.getPreferredAlignment(GV)) + GVSize);
+        alignTo(sizeof(GVMemoryBlock), TD.getPreferredAlign(GV)) + GVSize);
     new(RawMemory) GVMemoryBlock(GV);
     return static_cast<char*>(RawMemory) + sizeof(GVMemoryBlock);
   }
 
   void deleted() override {
     // We allocated with operator new and with some extra memory hanging off the
     // end, so don't just delete this.  I'm not sure if this is actually
     // required.

llvm/lib/IR/DataLayout.cpp

if (StructType *STy = GTI.getStructTypeOrNull()) {
       if (int64_t arrayIdx = cast<ConstantInt>(Idx)->getSExtValue())
         Result += arrayIdx * getTypeAllocSize(GTI.getIndexedType());
     }
   }
 
   return Result;
 }
 
-/// getPreferredAlignment - Return the preferred alignment of the specified
-/// global.  This includes an explicitly requested alignment (if the global
-/// has one).
-unsigned DataLayout::getPreferredAlignment(const GlobalVariable *GV) const {
-  unsigned GVAlignment = GV->getAlignment();
+/// getPreferredAlign - Return the preferred alignment of the specified global.
+/// This includes an explicitly requested alignment (if the global has one).
+Align DataLayout::getPreferredAlign(const GlobalVariable *GV) const {
+  MaybeAlign GVAlignment = GV->getAlign();
   // If a section is specified, always precisely honor explicit alignment,
   // so we don't insert padding into a section we don't control.
   if (GVAlignment && GV->hasSection())
-    return GVAlignment;
+    return *GVAlignment;
 
   // If no explicit alignment is specified, compute the alignment based on
   // the IR type. If an alignment is specified, increase it to match the ABI
   // alignment of the IR type.
   //
   // FIXME: Not sure it makes sense to use the alignment of the type if
   // there's already an explicit alignment specification.
   Type *ElemType = GV->getValueType();
-  unsigned Alignment = getPrefTypeAlignment(ElemType);
-  if (GVAlignment >= Alignment) {
-    Alignment = GVAlignment;
-  } else if (GVAlignment != 0) {
-    Alignment = std::max(GVAlignment, getABITypeAlignment(ElemType));
+  Align Alignment = getPrefTypeAlign(ElemType);
+  if (GVAlignment) {
+    if (*GVAlignment >= Alignment)
+      Alignment = *GVAlignment;
+    else
+      Alignment = std::max(*GVAlignment, getABITypeAlign(ElemType));
   }
 
   // If no explicit alignment is specified, and the global is large, increase
   // the alignment to 16.
   // FIXME: Why 16, specifically?
-  if (GV->hasInitializer() && GVAlignment == 0) {
-    if (Alignment < 16) {
+  if (GV->hasInitializer() && !GVAlignment) {
+    if (Alignment < Align(16)) {
       // If the global is not external, see if it is large.  If so, give it a
       // larger alignment.
       if (getTypeSizeInBits(ElemType) > 128)
-        Alignment = 16;    // 16-byte alignment.
+        Alignment = Align(16); // 16-byte alignment.
     }
   }
   return Alignment;
 }
-
-/// getPreferredAlignmentLog - Return the preferred alignment of the
-/// specified global, returned in log form.  This includes an explicitly
-/// requested alignment (if the global has one).
-unsigned DataLayout::getPreferredAlignmentLog(const GlobalVariable *GV) const {
-  return Log2_32(getPreferredAlignment(GV));
-}

llvm/lib/IR/Value.cpp

if (auto *GO = dyn_cast<GlobalObject>(this)) {
     if (!Alignment) {
       if (auto *GVar = dyn_cast<GlobalVariable>(GO)) {
         Type *ObjectType = GVar->getValueType();
         if (ObjectType->isSized()) {
           // If the object is defined in the current Module, we'll be giving
           // it the preferred alignment. Otherwise, we have to assume that it
           // may only have the minimum ABI alignment.
           if (GVar->isStrongDefinitionForLinker())
-            return Align(DL.getPreferredAlignment(GVar));
+            return DL.getPreferredAlign(GVar);
           else
             return DL.getABITypeAlign(ObjectType);
         }
       }
     }
     return Alignment.valueOrOne();
   } else if (const Argument *A = dyn_cast<Argument>(this)) {
     const MaybeAlign Alignment = A->getParamAlign();

llvm/lib/Target/ARM/ARMISelLowering.cpp

static SDValue promoteToConstantPool(const ARMTargetLowering *TLI,
   // The constant islands pass can only really deal with alignment requests
   // <= 4 bytes and cannot pad constants itself. Therefore we cannot promote
   // any type wanting greater alignment requirements than 4 bytes. We also
   // can only promote constants that are multiples of 4 bytes in size or
   // are paddable to a multiple of 4. Currently we only try and pad constants
   // that are strings for simplicity.
   auto *CDAInit = dyn_cast<ConstantDataArray>(Init);
   unsigned Size = DAG.getDataLayout().getTypeAllocSize(Init->getType());
-  unsigned PrefAlign = DAG.getDataLayout().getPreferredAlignment(GVar);
+  Align PrefAlign = DAG.getDataLayout().getPreferredAlign(GVar);
   unsigned RequiredPadding = 4 - (Size % 4);
   bool PaddingPossible =
     RequiredPadding == 4 || (CDAInit && CDAInit->isString());
   if (!PaddingPossible || PrefAlign > 4 || Size > ConstpoolPromotionMaxSize ||
       Size == 0)
     return SDValue();
 
   unsigned PaddedSize = Size + ((RequiredPadding == 4) ? 0 : RequiredPadding);

llvm/lib/Target/PowerPC/PPCAsmPrinter.cpp

void PPCAIXAsmPrinter::emitGlobalVariable(const GlobalVariable *GV) {
 
   // Switch to the containing csect.
   OutStreamer->SwitchSection(Csect);
 
   const DataLayout &DL = GV->getParent()->getDataLayout();
 
   // Handle common symbols.
   if (GVKind.isCommon() || GVKind.isBSSLocal()) {
-    unsigned Align =
-      GV->getAlignment() ? GV->getAlignment() : DL.getPreferredAlignment(GV);
+    Align Alignment = GV->getAlign().getValueOr(DL.getPreferredAlign(GV));
     uint64_t Size = DL.getTypeAllocSize(GV->getType()->getElementType());
 
     if (GVKind.isBSSLocal())
       OutStreamer->emitXCOFFLocalCommonSymbol(
           OutContext.getOrCreateSymbol(GVSym->getUnqualifiedName()), Size,
-          GVSym, Align);
+          GVSym, Alignment.value());
     else
-      OutStreamer->emitCommonSymbol(GVSym, Size, Align);
+      OutStreamer->emitCommonSymbol(GVSym, Size, Alignment.value());
     return;
   }
 
   MCSymbol *EmittedInitSym = GVSym;
   emitLinkage(GV, EmittedInitSym);
   emitAlignment(getGVAlignment(GV, DL), GV);
   OutStreamer->emitLabel(EmittedInitSym);
   emitGlobalConstant(GV->getParent()->getDataLayout(), GV->getInitializer());

llvm/lib/Target/Target.cpp

 }
 
 unsigned LLVMPreferredAlignmentOfType(LLVMTargetDataRef TD, LLVMTypeRef Ty) {
   return unwrap(TD)->getPrefTypeAlignment(unwrap(Ty));
 }
 
 unsigned LLVMPreferredAlignmentOfGlobal(LLVMTargetDataRef TD,
                                         LLVMValueRef GlobalVar) {
-  return unwrap(TD)->getPreferredAlignment(unwrap<GlobalVariable>(GlobalVar));
+  return unwrap(TD)
+      ->getPreferredAlign(unwrap<GlobalVariable>(GlobalVar))
+      .value();
 }
 
 unsigned LLVMElementAtOffset(LLVMTargetDataRef TD, LLVMTypeRef StructTy,
                              unsigned long long Offset) {
   StructType *STy = unwrap<StructType>(StructTy);
   return unwrap(TD)->getStructLayout(STy)->getElementContainingOffset(Offset);
 }
 
 unsigned long long LLVMOffsetOfElement(LLVMTargetDataRef TD, LLVMTypeRef StructTy,
                                        unsigned Element) {
   StructType *STy = unwrap<StructType>(StructTy);
   return unwrap(TD)->getStructLayout(STy)->getElementOffset(Element);
 }

llvm/lib/Transforms/IPO/ConstantMerge.cpp

 static void copyDebugLocMetadata(const GlobalVariable *From,
                                  GlobalVariable *To) {
   SmallVector<DIGlobalVariableExpression *, 1> MDs;
   From->getDebugInfo(MDs);
   for (auto MD : MDs)
     To->addDebugInfo(MD);
 }
 
-static unsigned getAlignment(GlobalVariable *GV) {
-  unsigned Align = GV->getAlignment();
-  if (Align)
-    return Align;
-  return GV->getParent()->getDataLayout().getPreferredAlignment(GV);
+static Align getAlign(GlobalVariable *GV) {
+  return GV->getAlign().getValueOr(
+      GV->getParent()->getDataLayout().getPreferredAlign(GV));
 }
 
 static bool
 isUnmergeableGlobal(GlobalVariable *GV,
                     const SmallPtrSetImpl<const GlobalValue *> &UsedGlobals) {
   // Only process constants with initializers in the default address space.
   return !GV->isConstant() || !GV->hasDefinitiveInitializer() ||
          GV->getType()->getAddressSpace() != 0 || GV->hasSection() ||

 
 static void replace(Module &M, GlobalVariable *Old, GlobalVariable *New) {
   Constant *NewConstant = New;
 
   LLVM_DEBUG(dbgs() << "Replacing global: @" << Old->getName() << " -> @"
                     << New->getName() << "\n");
 
   // Bump the alignment if necessary.
-  if (Old->getAlignment() || New->getAlignment())
-    New->setAlignment(Align(std::max(getAlignment(Old), getAlignment(New))));
+  if (Old->getAlign() || New->getAlign())
+    New->setAlignment(std::max(getAlign(Old), getAlign(New)));
 
   copyDebugLocMetadata(Old, New);
   Old->replaceAllUsesWith(NewConstant);
 
   // Delete the global value from the module.
   assert(Old->hasLocalLinkage() &&
          "Refusing to delete an externally visible global variable.");
   Old->eraseFromParent();