git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165243 91177308-0d34-0410-b5e6-96231b3b80d8

lib/VMCore/DataLayout.cpp

@@ -0,0 +1,665 @@
+//===-- TargetData.cpp - Data size & alignment routines --------------------==//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines target properties related to datatype size/offset/alignment
+// information.
+//
+// This structure should be created once, filled in if the defaults are not
+// correct and then passed around by const&.  None of the members functions
+// require modification to the object.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Target/TargetData.h"
+#include "llvm/Constants.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/Module.h"
+#include "llvm/Support/GetElementPtrTypeIterator.h"
+#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/Mutex.h"
+#include "llvm/ADT/DenseMap.h"
+#include <algorithm>
+#include <cstdlib>
+using namespace llvm;
+
+// Handle the Pass registration stuff necessary to use TargetData's.
+
+// Register the default SparcV9 implementation...
+INITIALIZE_PASS(TargetData, "targetdata", "Target Data Layout", false, true)
+char TargetData::ID = 0;
+
+//===----------------------------------------------------------------------===//
+// Support for StructLayout
+//===----------------------------------------------------------------------===//
+
+StructLayout::StructLayout(StructType *ST, const TargetData &TD) {
+  assert(!ST->isOpaque() && "Cannot get layout of opaque structs");
+  StructAlignment = 0;
+  StructSize = 0;
+  NumElements = ST->getNumElements();
+
+  // Loop over each of the elements, placing them in memory.
+  for (unsigned i = 0, e = NumElements; i != e; ++i) {
+    Type *Ty = ST->getElementType(i);
+    unsigned TyAlign = ST->isPacked() ? 1 : TD.getABITypeAlignment(Ty);
+
+    // Add padding if necessary to align the data element properly.
+    if ((StructSize & (TyAlign-1)) != 0)
+      StructSize = TargetData::RoundUpAlignment(StructSize, TyAlign);
+
+    // Keep track of maximum alignment constraint.
+    StructAlignment = std::max(TyAlign, StructAlignment);
+
+    MemberOffsets[i] = StructSize;
+    StructSize += TD.getTypeAllocSize(Ty); // Consume space for this data item
+  }
+
+  // Empty structures have alignment of 1 byte.
+  if (StructAlignment == 0) StructAlignment = 1;
+
+  // Add padding to the end of the struct so that it could be put in an array
+  // and all array elements would be aligned correctly.
+  if ((StructSize & (StructAlignment-1)) != 0)
+    StructSize = TargetData::RoundUpAlignment(StructSize, StructAlignment);
+}
+
+
+/// getElementContainingOffset - Given a valid offset into the structure,
+/// return the structure index that contains it.
+unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
+  const uint64_t *SI =
+    std::upper_bound(&MemberOffsets[0], &MemberOffsets[NumElements], Offset);
+  assert(SI != &MemberOffsets[0] && "Offset not in structure type!");
+  --SI;
+  assert(*SI <= Offset && "upper_bound didn't work");
+  assert((SI == &MemberOffsets[0] || *(SI-1) <= Offset) &&
+         (SI+1 == &MemberOffsets[NumElements] || *(SI+1) > Offset) &&
+         "Upper bound didn't work!");
+
+  // Multiple fields can have the same offset if any of them are zero sized.
+  // For example, in { i32, [0 x i32], i32 }, searching for offset 4 will stop
+  // at the i32 element, because it is the last element at that offset.  This is
+  // the right one to return, because anything after it will have a higher
+  // offset, implying that this element is non-empty.
+  return SI-&MemberOffsets[0];
+}
+
+//===----------------------------------------------------------------------===//
+// TargetAlignElem, TargetAlign support
+//===----------------------------------------------------------------------===//
+
+TargetAlignElem
+TargetAlignElem::get(AlignTypeEnum align_type, unsigned abi_align,
+                     unsigned pref_align, uint32_t bit_width) {
+  assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
+  TargetAlignElem retval;
+  retval.AlignType = align_type;
+  retval.ABIAlign = abi_align;
+  retval.PrefAlign = pref_align;
+  retval.TypeBitWidth = bit_width;
+  return retval;
+}
+
+bool
+TargetAlignElem::operator==(const TargetAlignElem &rhs) const {
+  return (AlignType == rhs.AlignType
+          && ABIAlign == rhs.ABIAlign
+          && PrefAlign == rhs.PrefAlign
+          && TypeBitWidth == rhs.TypeBitWidth);
+}
+
+const TargetAlignElem
+TargetData::InvalidAlignmentElem = { (AlignTypeEnum)0xFF, 0, 0, 0 };
+
+//===----------------------------------------------------------------------===//
+//                       TargetData Class Implementation
+//===----------------------------------------------------------------------===//
+
+/// getInt - Get an integer ignoring errors.
+static int getInt(StringRef R) {
+  int Result = 0;
+  R.getAsInteger(10, Result);
+  return Result;
+}
+
+void TargetData::init() {
+  initializeTargetDataPass(*PassRegistry::getPassRegistry());
+
+  LayoutMap = 0;
+  LittleEndian = false;
+  PointerMemSize = 8;
+  PointerABIAlign = 8;
+  PointerPrefAlign = PointerABIAlign;
+  StackNaturalAlign = 0;
+
+  // Default alignments
+  setAlignment(INTEGER_ALIGN,   1,  1, 1);   // i1
+  setAlignment(INTEGER_ALIGN,   1,  1, 8);   // i8
+  setAlignment(INTEGER_ALIGN,   2,  2, 16);  // i16
+  setAlignment(INTEGER_ALIGN,   4,  4, 32);  // i32
+  setAlignment(INTEGER_ALIGN,   4,  8, 64);  // i64
+  setAlignment(FLOAT_ALIGN,     2,  2, 16);  // half
+  setAlignment(FLOAT_ALIGN,     4,  4, 32);  // float
+  setAlignment(FLOAT_ALIGN,     8,  8, 64);  // double
+  setAlignment(FLOAT_ALIGN,    16, 16, 128); // ppcf128, quad, ...
+  setAlignment(VECTOR_ALIGN,    8,  8, 64);  // v2i32, v1i64, ...
+  setAlignment(VECTOR_ALIGN,   16, 16, 128); // v16i8, v8i16, v4i32, ...
+  setAlignment(AGGREGATE_ALIGN, 0,  8,  0);  // struct
+}
+
+std::string TargetData::parseSpecifier(StringRef Desc, TargetData *td) {
+
+  if (td)
+    td->init();
+
+  while (!Desc.empty()) {
+    std::pair<StringRef, StringRef> Split = Desc.split('-');
+    StringRef Token = Split.first;
+    Desc = Split.second;
+
+    if (Token.empty())
+      continue;
+
+    Split = Token.split(':');
+    StringRef Specifier = Split.first;
+    Token = Split.second;
+
+    assert(!Specifier.empty() && "Can't be empty here");
+
+    switch (Specifier[0]) {
+    case 'E':
+      if (td)
+        td->LittleEndian = false;
+      break;
+    case 'e':
+      if (td)
+        td->LittleEndian = true;
+      break;
+    case 'p': {
+      // Pointer size.
+      Split = Token.split(':');
+      int PointerMemSizeBits = getInt(Split.first);
+      if (PointerMemSizeBits < 0 || PointerMemSizeBits % 8 != 0)
+        return "invalid pointer size, must be a positive 8-bit multiple";
+      if (td)
+        td->PointerMemSize = PointerMemSizeBits / 8;
+
+      // Pointer ABI alignment.
+      Split = Split.second.split(':');
+      int PointerABIAlignBits = getInt(Split.first);
+      if (PointerABIAlignBits < 0 || PointerABIAlignBits % 8 != 0) {
+        return "invalid pointer ABI alignment, "
+               "must be a positive 8-bit multiple";
+      }
+      if (td)
+        td->PointerABIAlign = PointerABIAlignBits / 8;
+
+      // Pointer preferred alignment.
+      Split = Split.second.split(':');
+      int PointerPrefAlignBits = getInt(Split.first);
+      if (PointerPrefAlignBits < 0 || PointerPrefAlignBits % 8 != 0) {
+        return "invalid pointer preferred alignment, "
+               "must be a positive 8-bit multiple";
+      }
+      if (td) {
+        td->PointerPrefAlign = PointerPrefAlignBits / 8;
+        if (td->PointerPrefAlign == 0)
+          td->PointerPrefAlign = td->PointerABIAlign;
+      }
+      break;
+    }
+    case 'i':
+    case 'v':
+    case 'f':
+    case 'a':
+    case 's': {
+      AlignTypeEnum AlignType;
+      char field = Specifier[0];
+      switch (field) {
+      default:
+      case 'i': AlignType = INTEGER_ALIGN; break;
+      case 'v': AlignType = VECTOR_ALIGN; break;
+      case 'f': AlignType = FLOAT_ALIGN; break;
+      case 'a': AlignType = AGGREGATE_ALIGN; break;
+      case 's': AlignType = STACK_ALIGN; break;
+      }
+      int Size = getInt(Specifier.substr(1));
+      if (Size < 0) {
+        return std::string("invalid ") + field + "-size field, "
+               "must be positive";
+      }
+
+      Split = Token.split(':');
+      int ABIAlignBits = getInt(Split.first);
+      if (ABIAlignBits < 0 || ABIAlignBits % 8 != 0) {
+        return std::string("invalid ") + field +"-abi-alignment field, "
+               "must be a positive 8-bit multiple";
+      }
+      unsigned ABIAlign = ABIAlignBits / 8;
+
+      Split = Split.second.split(':');
+
+      int PrefAlignBits = getInt(Split.first);
+      if (PrefAlignBits < 0 || PrefAlignBits % 8 != 0) {
+        return std::string("invalid ") + field +"-preferred-alignment field, "
+               "must be a positive 8-bit multiple";
+      }
+      unsigned PrefAlign = PrefAlignBits / 8;
+      if (PrefAlign == 0)
+        PrefAlign = ABIAlign;
+      
+      if (td)
+        td->setAlignment(AlignType, ABIAlign, PrefAlign, Size);
+      break;
+    }
+    case 'n':  // Native integer types.
+      Specifier = Specifier.substr(1);
+      do {
+        int Width = getInt(Specifier);
+        if (Width <= 0) {
+          return std::string("invalid native integer size \'") + Specifier.str() +
+                 "\', must be a positive integer.";
+        }
+        if (td && Width != 0)
+          td->LegalIntWidths.push_back(Width);
+        Split = Token.split(':');
+        Specifier = Split.first;
+        Token = Split.second;
+      } while (!Specifier.empty() || !Token.empty());
+      break;
+    case 'S': { // Stack natural alignment.
+      int StackNaturalAlignBits = getInt(Specifier.substr(1));
+      if (StackNaturalAlignBits < 0 || StackNaturalAlignBits % 8 != 0) {
+        return "invalid natural stack alignment (S-field), "
+               "must be a positive 8-bit multiple";
+      }
+      if (td)
+        td->StackNaturalAlign = StackNaturalAlignBits / 8;
+      break;
+    }
+    default:
+      break;
+    }
+  }
+
+  return "";
+}
+
+/// Default ctor.
+///
+/// @note This has to exist, because this is a pass, but it should never be
+/// used.
+TargetData::TargetData() : ImmutablePass(ID) {
+  report_fatal_error("Bad TargetData ctor used.  "
+                    "Tool did not specify a TargetData to use?");
+}
+
+TargetData::TargetData(const Module *M)
+  : ImmutablePass(ID) {
+  std::string errMsg = parseSpecifier(M->getDataLayout(), this);
+  assert(errMsg == "" && "Module M has malformed target data layout string.");
+  (void)errMsg;
+}
+
+void
+TargetData::setAlignment(AlignTypeEnum align_type, unsigned abi_align,
+                         unsigned pref_align, uint32_t bit_width) {
+  assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
+  assert(pref_align < (1 << 16) && "Alignment doesn't fit in bitfield");
+  assert(bit_width < (1 << 24) && "Bit width doesn't fit in bitfield");
+  for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
+    if (Alignments[i].AlignType == align_type &&
+        Alignments[i].TypeBitWidth == bit_width) {
+      // Update the abi, preferred alignments.
+      Alignments[i].ABIAlign = abi_align;
+      Alignments[i].PrefAlign = pref_align;
+      return;
+    }
+  }
+
+  Alignments.push_back(TargetAlignElem::get(align_type, abi_align,
+                                            pref_align, bit_width));
+}
+
+/// getAlignmentInfo - Return the alignment (either ABI if ABIInfo = true or
+/// preferred if ABIInfo = false) the target wants for the specified datatype.
+unsigned TargetData::getAlignmentInfo(AlignTypeEnum AlignType,
+                                      uint32_t BitWidth, bool ABIInfo,
+                                      Type *Ty) const {
+  // Check to see if we have an exact match and remember the best match we see.
+  int BestMatchIdx = -1;
+  int LargestInt = -1;
+  for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
+    if (Alignments[i].AlignType == AlignType &&
+        Alignments[i].TypeBitWidth == BitWidth)
+      return ABIInfo ? Alignments[i].ABIAlign : Alignments[i].PrefAlign;
+
+    // The best match so far depends on what we're looking for.
+     if (AlignType == INTEGER_ALIGN &&
+         Alignments[i].AlignType == INTEGER_ALIGN) {
+      // The "best match" for integers is the smallest size that is larger than
+      // the BitWidth requested.
+      if (Alignments[i].TypeBitWidth > BitWidth && (BestMatchIdx == -1 ||
+           Alignments[i].TypeBitWidth < Alignments[BestMatchIdx].TypeBitWidth))
+        BestMatchIdx = i;
+      // However, if there isn't one that's larger, then we must use the
+      // largest one we have (see below)
+      if (LargestInt == -1 ||
+          Alignments[i].TypeBitWidth > Alignments[LargestInt].TypeBitWidth)
+        LargestInt = i;
+    }
+  }
+
+  // Okay, we didn't find an exact solution.  Fall back here depending on what
+  // is being looked for.
+  if (BestMatchIdx == -1) {
+    // If we didn't find an integer alignment, fall back on most conservative.
+    if (AlignType == INTEGER_ALIGN) {
+      BestMatchIdx = LargestInt;
+    } else {
+      assert(AlignType == VECTOR_ALIGN && "Unknown alignment type!");
+
+      // By default, use natural alignment for vector types. This is consistent
+      // with what clang and llvm-gcc do.
+      unsigned Align = getTypeAllocSize(cast<VectorType>(Ty)->getElementType());
+      Align *= cast<VectorType>(Ty)->getNumElements();
+      // If the alignment is not a power of 2, round up to the next power of 2.
+      // This happens for non-power-of-2 length vectors.
+      if (Align & (Align-1))
+        Align = NextPowerOf2(Align);
+      return Align;
+    }
+  }
+
+  // Since we got a "best match" index, just return it.
+  return ABIInfo ? Alignments[BestMatchIdx].ABIAlign
+                 : Alignments[BestMatchIdx].PrefAlign;
+}
+
+namespace {
+
+class StructLayoutMap {
+  typedef DenseMap<StructType*, StructLayout*> LayoutInfoTy;
+  LayoutInfoTy LayoutInfo;
+
+public:
+  virtual ~StructLayoutMap() {
+    // Remove any layouts.
+    for (LayoutInfoTy::iterator I = LayoutInfo.begin(), E = LayoutInfo.end();
+         I != E; ++I) {
+      StructLayout *Value = I->second;
+      Value->~StructLayout();
+      free(Value);
+    }
+  }
+
+  StructLayout *&operator[](StructType *STy) {
+    return LayoutInfo[STy];
+  }
+
+  // for debugging...
+  virtual void dump() const {}
+};
+
+} // end anonymous namespace
+
+TargetData::~TargetData() {
+  delete static_cast<StructLayoutMap*>(LayoutMap);
+}
+
+const StructLayout *TargetData::getStructLayout(StructType *Ty) const {
+  if (!LayoutMap)
+    LayoutMap = new StructLayoutMap();
+
+  StructLayoutMap *STM = static_cast<StructLayoutMap*>(LayoutMap);
+  StructLayout *&SL = (*STM)[Ty];
+  if (SL) return SL;
+
+  // Otherwise, create the struct layout.  Because it is variable length, we
+  // malloc it, then use placement new.
+  int NumElts = Ty->getNumElements();
+  StructLayout *L =
+    (StructLayout *)malloc(sizeof(StructLayout)+(NumElts-1) * sizeof(uint64_t));
+
+  // Set SL before calling StructLayout's ctor.  The ctor could cause other
+  // entries to be added to TheMap, invalidating our reference.
+  SL = L;
+
+  new (L) StructLayout(Ty, *this);
+
+  return L;
+}
+
+std::string TargetData::getStringRepresentation() const {
+  std::string Result;
+  raw_string_ostream OS(Result);
+
+  OS << (LittleEndian ? "e" : "E")
+     << "-p:" << PointerMemSize*8 << ':' << PointerABIAlign*8
+     << ':' << PointerPrefAlign*8
+     << "-S" << StackNaturalAlign*8;
+
+  for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
+    const TargetAlignElem &AI = Alignments[i];
+    OS << '-' << (char)AI.AlignType << AI.TypeBitWidth << ':'
+       << AI.ABIAlign*8 << ':' << AI.PrefAlign*8;
+  }
+
+  if (!LegalIntWidths.empty()) {
+    OS << "-n" << (unsigned)LegalIntWidths[0];
+
+    for (unsigned i = 1, e = LegalIntWidths.size(); i != e; ++i)
+      OS << ':' << (unsigned)LegalIntWidths[i];
+  }
+  return OS.str();
+}
+
+
+uint64_t TargetData::getTypeSizeInBits(Type *Ty) const {
+  assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
+  switch (Ty->getTypeID()) {
+  case Type::LabelTyID:
+  case Type::PointerTyID:
+    return getPointerSizeInBits();
+  case Type::ArrayTyID: {
+    ArrayType *ATy = cast<ArrayType>(Ty);
+    return getTypeAllocSizeInBits(ATy->getElementType())*ATy->getNumElements();
+  }
+  case Type::StructTyID:
+    // Get the layout annotation... which is lazily created on demand.
+    return getStructLayout(cast<StructType>(Ty))->getSizeInBits();
+  case Type::IntegerTyID:
+    return cast<IntegerType>(Ty)->getBitWidth();
+  case Type::VoidTyID:
+    return 8;
+  case Type::HalfTyID:
+    return 16;
+  case Type::FloatTyID:
+    return 32;
+  case Type::DoubleTyID:
+  case Type::X86_MMXTyID:
+    return 64;
+  case Type::PPC_FP128TyID:
+  case Type::FP128TyID:
+    return 128;
+  // In memory objects this is always aligned to a higher boundary, but
+  // only 80 bits contain information.
+  case Type::X86_FP80TyID:
+    return 80;
+  case Type::VectorTyID:
+    return cast<VectorType>(Ty)->getBitWidth();
+  default:
+    llvm_unreachable("TargetData::getTypeSizeInBits(): Unsupported type");
+  }
+}
+
+/*!
+  \param abi_or_pref Flag that determines which alignment is returned. true
+  returns the ABI alignment, false returns the preferred alignment.
+  \param Ty The underlying type for which alignment is determined.
+
+  Get the ABI (\a abi_or_pref == true) or preferred alignment (\a abi_or_pref
+  == false) for the requested type \a Ty.
+ */
+unsigned TargetData::getAlignment(Type *Ty, bool abi_or_pref) const {
+  int AlignType = -1;
+
+  assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
+  switch (Ty->getTypeID()) {
+  // Early escape for the non-numeric types.
+  case Type::LabelTyID:
+  case Type::PointerTyID:
+    return (abi_or_pref
+            ? getPointerABIAlignment()
+            : getPointerPrefAlignment());
+  case Type::ArrayTyID:
+    return getAlignment(cast<ArrayType>(Ty)->getElementType(), abi_or_pref);
+
+  case Type::StructTyID: {
+    // Packed structure types always have an ABI alignment of one.
+    if (cast<StructType>(Ty)->isPacked() && abi_or_pref)
+      return 1;
+
+    // Get the layout annotation... which is lazily created on demand.
+    const StructLayout *Layout = getStructLayout(cast<StructType>(Ty));
+    unsigned Align = getAlignmentInfo(AGGREGATE_ALIGN, 0, abi_or_pref, Ty);
+    return std::max(Align, Layout->getAlignment());
+  }
+  case Type::IntegerTyID:
+  case Type::VoidTyID:
+    AlignType = INTEGER_ALIGN;
+    break;
+  case Type::HalfTyID:
+  case Type::FloatTyID:
+  case Type::DoubleTyID:
+  // PPC_FP128TyID and FP128TyID have different data contents, but the
+  // same size and alignment, so they look the same here.
+  case Type::PPC_FP128TyID:
+  case Type::FP128TyID:
+  case Type::X86_FP80TyID:
+    AlignType = FLOAT_ALIGN;
+    break;
+  case Type::X86_MMXTyID:
+  case Type::VectorTyID:
+    AlignType = VECTOR_ALIGN;
+    break;
+  default:
+    llvm_unreachable("Bad type for getAlignment!!!");
+  }
+
+  return getAlignmentInfo((AlignTypeEnum)AlignType, getTypeSizeInBits(Ty),
+                          abi_or_pref, Ty);
+}
+
+unsigned TargetData::getABITypeAlignment(Type *Ty) const {
+  return getAlignment(Ty, true);
+}
+
+/// getABIIntegerTypeAlignment - Return the minimum ABI-required alignment for
+/// an integer type of the specified bitwidth.
+unsigned TargetData::getABIIntegerTypeAlignment(unsigned BitWidth) const {
+  return getAlignmentInfo(INTEGER_ALIGN, BitWidth, true, 0);
+}
+
+
+unsigned TargetData::getCallFrameTypeAlignment(Type *Ty) const {
+  for (unsigned i = 0, e = Alignments.size(); i != e; ++i)
+    if (Alignments[i].AlignType == STACK_ALIGN)
+      return Alignments[i].ABIAlign;
+
+  return getABITypeAlignment(Ty);
+}
+
+unsigned TargetData::getPrefTypeAlignment(Type *Ty) const {
+  return getAlignment(Ty, false);
+}
+
+unsigned TargetData::getPreferredTypeAlignmentShift(Type *Ty) const {
+  unsigned Align = getPrefTypeAlignment(Ty);
+  assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
+  return Log2_32(Align);
+}
+
+/// getIntPtrType - Return an unsigned integer type that is the same size or
+/// greater to the host pointer size.
+IntegerType *TargetData::getIntPtrType(LLVMContext &C) const {
+  return IntegerType::get(C, getPointerSizeInBits());
+}
+
+
+uint64_t TargetData::getIndexedOffset(Type *ptrTy,
+                                      ArrayRef<Value *> Indices) const {
+  Type *Ty = ptrTy;
+  assert(Ty->isPointerTy() && "Illegal argument for getIndexedOffset()");
+  uint64_t Result = 0;
+
+  generic_gep_type_iterator<Value* const*>
+    TI = gep_type_begin(ptrTy, Indices);
+  for (unsigned CurIDX = 0, EndIDX = Indices.size(); CurIDX != EndIDX;
+       ++CurIDX, ++TI) {
+    if (StructType *STy = dyn_cast<StructType>(*TI)) {
+      assert(Indices[CurIDX]->getType() ==
+             Type::getInt32Ty(ptrTy->getContext()) &&
+             "Illegal struct idx");
+      unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue();
+
+      // Get structure layout information...
+      const StructLayout *Layout = getStructLayout(STy);
+
+      // Add in the offset, as calculated by the structure layout info...
+      Result += Layout->getElementOffset(FieldNo);
+
+      // Update Ty to refer to current element
+      Ty = STy->getElementType(FieldNo);
+    } else {
+      // Update Ty to refer to current element
+      Ty = cast<SequentialType>(Ty)->getElementType();
+
+      // Get the array index and the size of each array element.
+      if (int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue())
+        Result += (uint64_t)arrayIdx * getTypeAllocSize(Ty);
+    }
+  }
+
+  return Result;
+}
+
+/// getPreferredAlignment - Return the preferred alignment of the specified
+/// global.  This includes an explicitly requested alignment (if the global
+/// has one).
+unsigned TargetData::getPreferredAlignment(const GlobalVariable *GV) const {
+  Type *ElemType = GV->getType()->getElementType();
+  unsigned Alignment = getPrefTypeAlignment(ElemType);
+  unsigned GVAlignment = GV->getAlignment();
+  if (GVAlignment >= Alignment) {
+    Alignment = GVAlignment;
+  } else if (GVAlignment != 0) {
+    Alignment = std::max(GVAlignment, getABITypeAlignment(ElemType));
+  }
+
+  if (GV->hasInitializer() && GVAlignment == 0) {
+    if (Alignment < 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.
+    }
+  }
+  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 TargetData::getPreferredAlignmentLog(const GlobalVariable *GV) const {
+  return Log2_32(getPreferredAlignment(GV));
+}