1 //===-- DataLayout.cpp - Data size & alignment routines --------------------==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines layout properties related to datatype size/offset/alignment
13 // This structure should be created once, filled in if the defaults are not
14 // correct and then passed around by const&. None of the members functions
15 // require modification to the object.
17 //===----------------------------------------------------------------------===//
19 #include "llvm/IR/DataLayout.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/DerivedTypes.h"
25 #include "llvm/IR/GetElementPtrTypeIterator.h"
26 #include "llvm/IR/Module.h"
27 #include "llvm/Support/ErrorHandling.h"
28 #include "llvm/Support/ManagedStatic.h"
29 #include "llvm/Support/MathExtras.h"
30 #include "llvm/Support/Mutex.h"
31 #include "llvm/Support/raw_ostream.h"
36 // Handle the Pass registration stuff necessary to use DataLayout's.
38 INITIALIZE_PASS(DataLayoutPass, "datalayout", "Data Layout", false, true)
39 char DataLayoutPass::ID = 0;
41 //===----------------------------------------------------------------------===//
42 // Support for StructLayout
43 //===----------------------------------------------------------------------===//
45 StructLayout::StructLayout(StructType *ST, const DataLayout &DL) {
46 assert(!ST->isOpaque() && "Cannot get layout of opaque structs");
49 NumElements = ST->getNumElements();
51 // Loop over each of the elements, placing them in memory.
52 for (unsigned i = 0, e = NumElements; i != e; ++i) {
53 Type *Ty = ST->getElementType(i);
54 unsigned TyAlign = ST->isPacked() ? 1 : DL.getABITypeAlignment(Ty);
56 // Add padding if necessary to align the data element properly.
57 if ((StructSize & (TyAlign-1)) != 0)
58 StructSize = RoundUpToAlignment(StructSize, TyAlign);
60 // Keep track of maximum alignment constraint.
61 StructAlignment = std::max(TyAlign, StructAlignment);
63 MemberOffsets[i] = StructSize;
64 StructSize += DL.getTypeAllocSize(Ty); // Consume space for this data item
67 // Empty structures have alignment of 1 byte.
68 if (StructAlignment == 0) StructAlignment = 1;
70 // Add padding to the end of the struct so that it could be put in an array
71 // and all array elements would be aligned correctly.
72 if ((StructSize & (StructAlignment-1)) != 0)
73 StructSize = RoundUpToAlignment(StructSize, StructAlignment);
77 /// getElementContainingOffset - Given a valid offset into the structure,
78 /// return the structure index that contains it.
79 unsigned StructLayout::getElementContainingOffset(uint64_t Offset) const {
81 std::upper_bound(&MemberOffsets[0], &MemberOffsets[NumElements], Offset);
82 assert(SI != &MemberOffsets[0] && "Offset not in structure type!");
84 assert(*SI <= Offset && "upper_bound didn't work");
85 assert((SI == &MemberOffsets[0] || *(SI-1) <= Offset) &&
86 (SI+1 == &MemberOffsets[NumElements] || *(SI+1) > Offset) &&
87 "Upper bound didn't work!");
89 // Multiple fields can have the same offset if any of them are zero sized.
90 // For example, in { i32, [0 x i32], i32 }, searching for offset 4 will stop
91 // at the i32 element, because it is the last element at that offset. This is
92 // the right one to return, because anything after it will have a higher
93 // offset, implying that this element is non-empty.
94 return SI-&MemberOffsets[0];
97 //===----------------------------------------------------------------------===//
98 // LayoutAlignElem, LayoutAlign support
99 //===----------------------------------------------------------------------===//
102 LayoutAlignElem::get(AlignTypeEnum align_type, unsigned abi_align,
103 unsigned pref_align, uint32_t bit_width) {
104 assert(abi_align <= pref_align && "Preferred alignment worse than ABI!");
105 LayoutAlignElem retval;
106 retval.AlignType = align_type;
107 retval.ABIAlign = abi_align;
108 retval.PrefAlign = pref_align;
109 retval.TypeBitWidth = bit_width;
114 LayoutAlignElem::operator==(const LayoutAlignElem &rhs) const {
115 return (AlignType == rhs.AlignType
116 && ABIAlign == rhs.ABIAlign
117 && PrefAlign == rhs.PrefAlign
118 && TypeBitWidth == rhs.TypeBitWidth);
121 const LayoutAlignElem
122 DataLayout::InvalidAlignmentElem = { INVALID_ALIGN, 0, 0, 0 };
124 //===----------------------------------------------------------------------===//
125 // PointerAlignElem, PointerAlign support
126 //===----------------------------------------------------------------------===//
129 PointerAlignElem::get(uint32_t AddressSpace, unsigned ABIAlign,
130 unsigned PrefAlign, uint32_t TypeByteWidth) {
131 assert(ABIAlign <= PrefAlign && "Preferred alignment worse than ABI!");
132 PointerAlignElem retval;
133 retval.AddressSpace = AddressSpace;
134 retval.ABIAlign = ABIAlign;
135 retval.PrefAlign = PrefAlign;
136 retval.TypeByteWidth = TypeByteWidth;
141 PointerAlignElem::operator==(const PointerAlignElem &rhs) const {
142 return (ABIAlign == rhs.ABIAlign
143 && AddressSpace == rhs.AddressSpace
144 && PrefAlign == rhs.PrefAlign
145 && TypeByteWidth == rhs.TypeByteWidth);
148 const PointerAlignElem
149 DataLayout::InvalidPointerElem = { 0U, 0U, 0U, ~0U };
151 //===----------------------------------------------------------------------===//
152 // DataLayout Class Implementation
153 //===----------------------------------------------------------------------===//
155 const char *DataLayout::getManglingComponent(const Triple &T) {
156 if (T.isOSBinFormatMachO())
158 if (T.isOSWindows() && T.getArch() == Triple::x86 && T.isOSBinFormatCOFF())
163 static const LayoutAlignElem DefaultAlignments[] = {
164 { INTEGER_ALIGN, 1, 1, 1 }, // i1
165 { INTEGER_ALIGN, 8, 1, 1 }, // i8
166 { INTEGER_ALIGN, 16, 2, 2 }, // i16
167 { INTEGER_ALIGN, 32, 4, 4 }, // i32
168 { INTEGER_ALIGN, 64, 4, 8 }, // i64
169 { FLOAT_ALIGN, 16, 2, 2 }, // half
170 { FLOAT_ALIGN, 32, 4, 4 }, // float
171 { FLOAT_ALIGN, 64, 8, 8 }, // double
172 { FLOAT_ALIGN, 128, 16, 16 }, // ppcf128, quad, ...
173 { VECTOR_ALIGN, 64, 8, 8 }, // v2i32, v1i64, ...
174 { VECTOR_ALIGN, 128, 16, 16 }, // v16i8, v8i16, v4i32, ...
175 { AGGREGATE_ALIGN, 0, 0, 8 } // struct
178 void DataLayout::reset(StringRef Desc) {
183 StackNaturalAlign = 0;
184 ManglingMode = MM_None;
186 // Default alignments
187 for (const LayoutAlignElem &E : DefaultAlignments) {
188 setAlignment((AlignTypeEnum)E.AlignType, E.ABIAlign, E.PrefAlign,
191 setPointerAlignment(0, 8, 8, 8);
193 parseSpecifier(Desc);
196 /// Checked version of split, to ensure mandatory subparts.
197 static std::pair<StringRef, StringRef> split(StringRef Str, char Separator) {
198 assert(!Str.empty() && "parse error, string can't be empty here");
199 std::pair<StringRef, StringRef> Split = Str.split(Separator);
200 if (Split.second.empty() && Split.first != Str)
201 report_fatal_error("Trailing separator in datalayout string");
202 if (!Split.second.empty() && Split.first.empty())
203 report_fatal_error("Expected token before separator in datalayout string");
207 /// Get an unsigned integer, including error checks.
208 static unsigned getInt(StringRef R) {
210 bool error = R.getAsInteger(10, Result); (void)error;
212 report_fatal_error("not a number, or does not fit in an unsigned int");
216 /// Convert bits into bytes. Assert if not a byte width multiple.
217 static unsigned inBytes(unsigned Bits) {
219 report_fatal_error("number of bits must be a byte width multiple");
223 void DataLayout::parseSpecifier(StringRef Desc) {
224 while (!Desc.empty()) {
226 std::pair<StringRef, StringRef> Split = split(Desc, '-');
230 Split = split(Split.first, ':');
232 // Aliases used below.
233 StringRef &Tok = Split.first; // Current token.
234 StringRef &Rest = Split.second; // The rest of the string.
236 char Specifier = Tok.front();
241 // Ignored for backward compatibility.
242 // FIXME: remove this on LLVM 4.0.
252 unsigned AddrSpace = Tok.empty() ? 0 : getInt(Tok);
253 if (!isUInt<24>(AddrSpace))
254 report_fatal_error("Invalid address space, must be a 24bit integer");
259 "Missing size specification for pointer in datalayout string");
260 Split = split(Rest, ':');
261 unsigned PointerMemSize = inBytes(getInt(Tok));
263 report_fatal_error("Invalid pointer size of 0 bytes");
268 "Missing alignment specification for pointer in datalayout string");
269 Split = split(Rest, ':');
270 unsigned PointerABIAlign = inBytes(getInt(Tok));
271 if (!isPowerOf2_64(PointerABIAlign))
273 "Pointer ABI alignment must be a power of 2");
275 // Preferred alignment.
276 unsigned PointerPrefAlign = PointerABIAlign;
278 Split = split(Rest, ':');
279 PointerPrefAlign = inBytes(getInt(Tok));
280 if (!isPowerOf2_64(PointerPrefAlign))
282 "Pointer preferred alignment must be a power of 2");
285 setPointerAlignment(AddrSpace, PointerABIAlign, PointerPrefAlign,
293 AlignTypeEnum AlignType;
296 case 'i': AlignType = INTEGER_ALIGN; break;
297 case 'v': AlignType = VECTOR_ALIGN; break;
298 case 'f': AlignType = FLOAT_ALIGN; break;
299 case 'a': AlignType = AGGREGATE_ALIGN; break;
303 unsigned Size = Tok.empty() ? 0 : getInt(Tok);
305 if (AlignType == AGGREGATE_ALIGN && Size != 0)
307 "Sized aggregate specification in datalayout string");
312 "Missing alignment specification in datalayout string");
313 Split = split(Rest, ':');
314 unsigned ABIAlign = inBytes(getInt(Tok));
315 if (AlignType != AGGREGATE_ALIGN && !ABIAlign)
317 "ABI alignment specification must be >0 for non-aggregate types");
319 // Preferred alignment.
320 unsigned PrefAlign = ABIAlign;
322 Split = split(Rest, ':');
323 PrefAlign = inBytes(getInt(Tok));
326 setAlignment(AlignType, ABIAlign, PrefAlign, Size);
330 case 'n': // Native integer types.
332 unsigned Width = getInt(Tok);
335 "Zero width native integer type in datalayout string");
336 LegalIntWidths.push_back(Width);
339 Split = split(Rest, ':');
342 case 'S': { // Stack natural alignment.
343 StackNaturalAlign = inBytes(getInt(Tok));
348 report_fatal_error("Unexpected trailing characters after mangling specifier in datalayout string");
350 report_fatal_error("Expected mangling specifier in datalayout string");
352 report_fatal_error("Unknown mangling specifier in datalayout string");
355 report_fatal_error("Unknown mangling in datalayout string");
357 ManglingMode = MM_ELF;
360 ManglingMode = MM_MachO;
363 ManglingMode = MM_Mips;
366 ManglingMode = MM_WINCOFF;
371 report_fatal_error("Unknown specifier in datalayout string");
377 DataLayout::DataLayout(const Module *M) : LayoutMap(nullptr) {
381 void DataLayout::init(const Module *M) {
382 const DataLayout *Other = M->getDataLayout();
389 bool DataLayout::operator==(const DataLayout &Other) const {
390 bool Ret = BigEndian == Other.BigEndian &&
391 StackNaturalAlign == Other.StackNaturalAlign &&
392 ManglingMode == Other.ManglingMode &&
393 LegalIntWidths == Other.LegalIntWidths &&
394 Alignments == Other.Alignments && Pointers == Other.Pointers;
395 assert(Ret == (getStringRepresentation() == Other.getStringRepresentation()));
400 DataLayout::setAlignment(AlignTypeEnum align_type, unsigned abi_align,
401 unsigned pref_align, uint32_t bit_width) {
402 if (!isUInt<24>(bit_width))
403 report_fatal_error("Invalid bit width, must be a 24bit integer");
404 if (!isUInt<16>(abi_align))
405 report_fatal_error("Invalid ABI alignment, must be a 16bit integer");
406 if (!isUInt<16>(pref_align))
407 report_fatal_error("Invalid preferred alignment, must be a 16bit integer");
408 if (abi_align != 0 && !isPowerOf2_64(abi_align))
409 report_fatal_error("Invalid ABI alignment, must be a power of 2");
410 if (pref_align != 0 && !isPowerOf2_64(pref_align))
411 report_fatal_error("Invalid preferred alignment, must be a power of 2");
413 if (pref_align < abi_align)
415 "Preferred alignment cannot be less than the ABI alignment");
417 for (LayoutAlignElem &Elem : Alignments) {
418 if (Elem.AlignType == (unsigned)align_type &&
419 Elem.TypeBitWidth == bit_width) {
420 // Update the abi, preferred alignments.
421 Elem.ABIAlign = abi_align;
422 Elem.PrefAlign = pref_align;
427 Alignments.push_back(LayoutAlignElem::get(align_type, abi_align,
428 pref_align, bit_width));
431 DataLayout::PointersTy::iterator
432 DataLayout::findPointerLowerBound(uint32_t AddressSpace) {
433 return std::lower_bound(Pointers.begin(), Pointers.end(), AddressSpace,
434 [](const PointerAlignElem &A, uint32_t AddressSpace) {
435 return A.AddressSpace < AddressSpace;
439 void DataLayout::setPointerAlignment(uint32_t AddrSpace, unsigned ABIAlign,
441 uint32_t TypeByteWidth) {
442 if (PrefAlign < ABIAlign)
444 "Preferred alignment cannot be less than the ABI alignment");
446 PointersTy::iterator I = findPointerLowerBound(AddrSpace);
447 if (I == Pointers.end() || I->AddressSpace != AddrSpace) {
448 Pointers.insert(I, PointerAlignElem::get(AddrSpace, ABIAlign, PrefAlign,
451 I->ABIAlign = ABIAlign;
452 I->PrefAlign = PrefAlign;
453 I->TypeByteWidth = TypeByteWidth;
457 /// getAlignmentInfo - Return the alignment (either ABI if ABIInfo = true or
458 /// preferred if ABIInfo = false) the layout wants for the specified datatype.
459 unsigned DataLayout::getAlignmentInfo(AlignTypeEnum AlignType,
460 uint32_t BitWidth, bool ABIInfo,
462 // Check to see if we have an exact match and remember the best match we see.
463 int BestMatchIdx = -1;
465 for (unsigned i = 0, e = Alignments.size(); i != e; ++i) {
466 if (Alignments[i].AlignType == (unsigned)AlignType &&
467 Alignments[i].TypeBitWidth == BitWidth)
468 return ABIInfo ? Alignments[i].ABIAlign : Alignments[i].PrefAlign;
470 // The best match so far depends on what we're looking for.
471 if (AlignType == INTEGER_ALIGN &&
472 Alignments[i].AlignType == INTEGER_ALIGN) {
473 // The "best match" for integers is the smallest size that is larger than
474 // the BitWidth requested.
475 if (Alignments[i].TypeBitWidth > BitWidth && (BestMatchIdx == -1 ||
476 Alignments[i].TypeBitWidth < Alignments[BestMatchIdx].TypeBitWidth))
478 // However, if there isn't one that's larger, then we must use the
479 // largest one we have (see below)
480 if (LargestInt == -1 ||
481 Alignments[i].TypeBitWidth > Alignments[LargestInt].TypeBitWidth)
486 // Okay, we didn't find an exact solution. Fall back here depending on what
487 // is being looked for.
488 if (BestMatchIdx == -1) {
489 // If we didn't find an integer alignment, fall back on most conservative.
490 if (AlignType == INTEGER_ALIGN) {
491 BestMatchIdx = LargestInt;
493 assert(AlignType == VECTOR_ALIGN && "Unknown alignment type!");
495 // By default, use natural alignment for vector types. This is consistent
496 // with what clang and llvm-gcc do.
497 unsigned Align = getTypeAllocSize(cast<VectorType>(Ty)->getElementType());
498 Align *= cast<VectorType>(Ty)->getNumElements();
499 // If the alignment is not a power of 2, round up to the next power of 2.
500 // This happens for non-power-of-2 length vectors.
501 if (Align & (Align-1))
502 Align = NextPowerOf2(Align);
507 // Since we got a "best match" index, just return it.
508 return ABIInfo ? Alignments[BestMatchIdx].ABIAlign
509 : Alignments[BestMatchIdx].PrefAlign;
514 class StructLayoutMap {
515 typedef DenseMap<StructType*, StructLayout*> LayoutInfoTy;
516 LayoutInfoTy LayoutInfo;
520 // Remove any layouts.
521 for (const auto &I : LayoutInfo) {
522 StructLayout *Value = I.second;
523 Value->~StructLayout();
528 StructLayout *&operator[](StructType *STy) {
529 return LayoutInfo[STy];
533 } // end anonymous namespace
535 void DataLayout::clear() {
536 LegalIntWidths.clear();
539 delete static_cast<StructLayoutMap *>(LayoutMap);
543 DataLayout::~DataLayout() {
547 const StructLayout *DataLayout::getStructLayout(StructType *Ty) const {
549 LayoutMap = new StructLayoutMap();
551 StructLayoutMap *STM = static_cast<StructLayoutMap*>(LayoutMap);
552 StructLayout *&SL = (*STM)[Ty];
555 // Otherwise, create the struct layout. Because it is variable length, we
556 // malloc it, then use placement new.
557 int NumElts = Ty->getNumElements();
559 (StructLayout *)malloc(sizeof(StructLayout)+(NumElts-1) * sizeof(uint64_t));
561 // Set SL before calling StructLayout's ctor. The ctor could cause other
562 // entries to be added to TheMap, invalidating our reference.
565 new (L) StructLayout(Ty, *this);
570 std::string DataLayout::getStringRepresentation() const {
572 raw_string_ostream OS(Result);
574 OS << (BigEndian ? "E" : "e");
576 switch (ManglingMode) {
593 for (const PointerAlignElem &PI : Pointers) {
595 if (PI.AddressSpace == 0 && PI.ABIAlign == 8 && PI.PrefAlign == 8 &&
596 PI.TypeByteWidth == 8)
600 if (PI.AddressSpace) {
601 OS << PI.AddressSpace;
603 OS << ":" << PI.TypeByteWidth*8 << ':' << PI.ABIAlign*8;
604 if (PI.PrefAlign != PI.ABIAlign)
605 OS << ':' << PI.PrefAlign*8;
608 for (const LayoutAlignElem &AI : Alignments) {
609 if (std::find(std::begin(DefaultAlignments), std::end(DefaultAlignments),
610 AI) != std::end(DefaultAlignments))
612 OS << '-' << (char)AI.AlignType;
614 OS << AI.TypeBitWidth;
615 OS << ':' << AI.ABIAlign*8;
616 if (AI.ABIAlign != AI.PrefAlign)
617 OS << ':' << AI.PrefAlign*8;
620 if (!LegalIntWidths.empty()) {
621 OS << "-n" << (unsigned)LegalIntWidths[0];
623 for (unsigned i = 1, e = LegalIntWidths.size(); i != e; ++i)
624 OS << ':' << (unsigned)LegalIntWidths[i];
627 if (StackNaturalAlign)
628 OS << "-S" << StackNaturalAlign*8;
633 unsigned DataLayout::getPointerABIAlignment(unsigned AS) const {
634 PointersTy::const_iterator I = findPointerLowerBound(AS);
635 if (I == Pointers.end() || I->AddressSpace != AS) {
636 I = findPointerLowerBound(0);
637 assert(I->AddressSpace == 0);
642 unsigned DataLayout::getPointerPrefAlignment(unsigned AS) const {
643 PointersTy::const_iterator I = findPointerLowerBound(AS);
644 if (I == Pointers.end() || I->AddressSpace != AS) {
645 I = findPointerLowerBound(0);
646 assert(I->AddressSpace == 0);
651 unsigned DataLayout::getPointerSize(unsigned AS) const {
652 PointersTy::const_iterator I = findPointerLowerBound(AS);
653 if (I == Pointers.end() || I->AddressSpace != AS) {
654 I = findPointerLowerBound(0);
655 assert(I->AddressSpace == 0);
657 return I->TypeByteWidth;
660 unsigned DataLayout::getPointerTypeSizeInBits(Type *Ty) const {
661 assert(Ty->isPtrOrPtrVectorTy() &&
662 "This should only be called with a pointer or pointer vector type");
664 if (Ty->isPointerTy())
665 return getTypeSizeInBits(Ty);
667 return getTypeSizeInBits(Ty->getScalarType());
671 \param abi_or_pref Flag that determines which alignment is returned. true
672 returns the ABI alignment, false returns the preferred alignment.
673 \param Ty The underlying type for which alignment is determined.
675 Get the ABI (\a abi_or_pref == true) or preferred alignment (\a abi_or_pref
676 == false) for the requested type \a Ty.
678 unsigned DataLayout::getAlignment(Type *Ty, bool abi_or_pref) const {
681 assert(Ty->isSized() && "Cannot getTypeInfo() on a type that is unsized!");
682 switch (Ty->getTypeID()) {
683 // Early escape for the non-numeric types.
684 case Type::LabelTyID:
686 ? getPointerABIAlignment(0)
687 : getPointerPrefAlignment(0));
688 case Type::PointerTyID: {
689 unsigned AS = cast<PointerType>(Ty)->getAddressSpace();
691 ? getPointerABIAlignment(AS)
692 : getPointerPrefAlignment(AS));
694 case Type::ArrayTyID:
695 return getAlignment(cast<ArrayType>(Ty)->getElementType(), abi_or_pref);
697 case Type::StructTyID: {
698 // Packed structure types always have an ABI alignment of one.
699 if (cast<StructType>(Ty)->isPacked() && abi_or_pref)
702 // Get the layout annotation... which is lazily created on demand.
703 const StructLayout *Layout = getStructLayout(cast<StructType>(Ty));
704 unsigned Align = getAlignmentInfo(AGGREGATE_ALIGN, 0, abi_or_pref, Ty);
705 return std::max(Align, Layout->getAlignment());
707 case Type::IntegerTyID:
708 AlignType = INTEGER_ALIGN;
711 case Type::FloatTyID:
712 case Type::DoubleTyID:
713 // PPC_FP128TyID and FP128TyID have different data contents, but the
714 // same size and alignment, so they look the same here.
715 case Type::PPC_FP128TyID:
716 case Type::FP128TyID:
717 case Type::X86_FP80TyID:
718 AlignType = FLOAT_ALIGN;
720 case Type::X86_MMXTyID:
721 case Type::VectorTyID:
722 AlignType = VECTOR_ALIGN;
725 llvm_unreachable("Bad type for getAlignment!!!");
728 return getAlignmentInfo((AlignTypeEnum)AlignType, getTypeSizeInBits(Ty),
732 unsigned DataLayout::getABITypeAlignment(Type *Ty) const {
733 return getAlignment(Ty, true);
736 /// getABIIntegerTypeAlignment - Return the minimum ABI-required alignment for
737 /// an integer type of the specified bitwidth.
738 unsigned DataLayout::getABIIntegerTypeAlignment(unsigned BitWidth) const {
739 return getAlignmentInfo(INTEGER_ALIGN, BitWidth, true, nullptr);
742 unsigned DataLayout::getPrefTypeAlignment(Type *Ty) const {
743 return getAlignment(Ty, false);
746 unsigned DataLayout::getPreferredTypeAlignmentShift(Type *Ty) const {
747 unsigned Align = getPrefTypeAlignment(Ty);
748 assert(!(Align & (Align-1)) && "Alignment is not a power of two!");
749 return Log2_32(Align);
752 IntegerType *DataLayout::getIntPtrType(LLVMContext &C,
753 unsigned AddressSpace) const {
754 return IntegerType::get(C, getPointerSizeInBits(AddressSpace));
757 Type *DataLayout::getIntPtrType(Type *Ty) const {
758 assert(Ty->isPtrOrPtrVectorTy() &&
759 "Expected a pointer or pointer vector type.");
760 unsigned NumBits = getPointerTypeSizeInBits(Ty);
761 IntegerType *IntTy = IntegerType::get(Ty->getContext(), NumBits);
762 if (VectorType *VecTy = dyn_cast<VectorType>(Ty))
763 return VectorType::get(IntTy, VecTy->getNumElements());
767 Type *DataLayout::getSmallestLegalIntType(LLVMContext &C, unsigned Width) const {
768 for (unsigned LegalIntWidth : LegalIntWidths)
769 if (Width <= LegalIntWidth)
770 return Type::getIntNTy(C, LegalIntWidth);
774 unsigned DataLayout::getLargestLegalIntTypeSize() const {
775 auto Max = std::max_element(LegalIntWidths.begin(), LegalIntWidths.end());
776 return Max != LegalIntWidths.end() ? *Max : 0;
779 uint64_t DataLayout::getIndexedOffset(Type *ptrTy,
780 ArrayRef<Value *> Indices) const {
782 assert(Ty->isPointerTy() && "Illegal argument for getIndexedOffset()");
785 generic_gep_type_iterator<Value* const*>
786 TI = gep_type_begin(ptrTy, Indices);
787 for (unsigned CurIDX = 0, EndIDX = Indices.size(); CurIDX != EndIDX;
789 if (StructType *STy = dyn_cast<StructType>(*TI)) {
790 assert(Indices[CurIDX]->getType() ==
791 Type::getInt32Ty(ptrTy->getContext()) &&
792 "Illegal struct idx");
793 unsigned FieldNo = cast<ConstantInt>(Indices[CurIDX])->getZExtValue();
795 // Get structure layout information...
796 const StructLayout *Layout = getStructLayout(STy);
798 // Add in the offset, as calculated by the structure layout info...
799 Result += Layout->getElementOffset(FieldNo);
801 // Update Ty to refer to current element
802 Ty = STy->getElementType(FieldNo);
804 // Update Ty to refer to current element
805 Ty = cast<SequentialType>(Ty)->getElementType();
807 // Get the array index and the size of each array element.
808 if (int64_t arrayIdx = cast<ConstantInt>(Indices[CurIDX])->getSExtValue())
809 Result += (uint64_t)arrayIdx * getTypeAllocSize(Ty);
816 /// getPreferredAlignment - Return the preferred alignment of the specified
817 /// global. This includes an explicitly requested alignment (if the global
819 unsigned DataLayout::getPreferredAlignment(const GlobalVariable *GV) const {
820 Type *ElemType = GV->getType()->getElementType();
821 unsigned Alignment = getPrefTypeAlignment(ElemType);
822 unsigned GVAlignment = GV->getAlignment();
823 if (GVAlignment >= Alignment) {
824 Alignment = GVAlignment;
825 } else if (GVAlignment != 0) {
826 Alignment = std::max(GVAlignment, getABITypeAlignment(ElemType));
829 if (GV->hasInitializer() && GVAlignment == 0) {
830 if (Alignment < 16) {
831 // If the global is not external, see if it is large. If so, give it a
833 if (getTypeSizeInBits(ElemType) > 128)
834 Alignment = 16; // 16-byte alignment.
840 /// getPreferredAlignmentLog - Return the preferred alignment of the
841 /// specified global, returned in log form. This includes an explicitly
842 /// requested alignment (if the global has one).
843 unsigned DataLayout::getPreferredAlignmentLog(const GlobalVariable *GV) const {
844 return Log2_32(getPreferredAlignment(GV));
847 DataLayoutPass::DataLayoutPass() : ImmutablePass(ID), DL("") {
848 initializeDataLayoutPassPass(*PassRegistry::getPassRegistry());
851 DataLayoutPass::~DataLayoutPass() {}
853 bool DataLayoutPass::doInitialization(Module &M) {
858 bool DataLayoutPass::doFinalization(Module &M) {