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authorMicah Villmow <villmow@gmail.com>2012-10-04 20:44:22 +0000
committerMicah Villmow <villmow@gmail.com>2012-10-04 20:44:22 +0000
commit726b88fb6a3242bbbe6c6c486a18dfa6f6ed11a6 (patch)
tree32970badd59ebd2b23e3ba2a437f205eaee32a09 /lib/VMCore/DataLayout.cpp
parent2d6d585c85ce8c56461f17b7b49fff24eed7b8fb (diff)
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Create the DataLayout class, as a direct copy of TargetData.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165249 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/VMCore/DataLayout.cpp')
-rw-r--r--lib/VMCore/DataLayout.cpp665
1 files changed, 665 insertions, 0 deletions
diff --git a/lib/VMCore/DataLayout.cpp b/lib/VMCore/DataLayout.cpp
new file mode 100644
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--- /dev/null
+++ b/lib/VMCore/DataLayout.cpp
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+//===-- 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));
+}