LLVM API Documentation

Type.cpp
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00001 //===-- Type.cpp - Implement the Type class -------------------------------===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file is distributed under the University of Illinois Open Source
00006 // License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This file implements the Type class for the IR library.
00011 //
00012 //===----------------------------------------------------------------------===//
00013 
00014 #include "llvm/IR/Type.h"
00015 #include "LLVMContextImpl.h"
00016 #include "llvm/ADT/SmallString.h"
00017 #include "llvm/IR/Module.h"
00018 #include <algorithm>
00019 #include <cstdarg>
00020 using namespace llvm;
00021 
00022 //===----------------------------------------------------------------------===//
00023 //                         Type Class Implementation
00024 //===----------------------------------------------------------------------===//
00025 
00026 Type *Type::getPrimitiveType(LLVMContext &C, TypeID IDNumber) {
00027   switch (IDNumber) {
00028   case VoidTyID      : return getVoidTy(C);
00029   case HalfTyID      : return getHalfTy(C);
00030   case FloatTyID     : return getFloatTy(C);
00031   case DoubleTyID    : return getDoubleTy(C);
00032   case X86_FP80TyID  : return getX86_FP80Ty(C);
00033   case FP128TyID     : return getFP128Ty(C);
00034   case PPC_FP128TyID : return getPPC_FP128Ty(C);
00035   case LabelTyID     : return getLabelTy(C);
00036   case MetadataTyID  : return getMetadataTy(C);
00037   case X86_MMXTyID   : return getX86_MMXTy(C);
00038   default:
00039     return nullptr;
00040   }
00041 }
00042 
00043 /// getScalarType - If this is a vector type, return the element type,
00044 /// otherwise return this.
00045 Type *Type::getScalarType() {
00046   if (VectorType *VTy = dyn_cast<VectorType>(this))
00047     return VTy->getElementType();
00048   return this;
00049 }
00050 
00051 const Type *Type::getScalarType() const {
00052   if (const VectorType *VTy = dyn_cast<VectorType>(this))
00053     return VTy->getElementType();
00054   return this;
00055 }
00056 
00057 /// isIntegerTy - Return true if this is an IntegerType of the specified width.
00058 bool Type::isIntegerTy(unsigned Bitwidth) const {
00059   return isIntegerTy() && cast<IntegerType>(this)->getBitWidth() == Bitwidth;
00060 }
00061 
00062 // canLosslesslyBitCastTo - Return true if this type can be converted to
00063 // 'Ty' without any reinterpretation of bits.  For example, i8* to i32*.
00064 //
00065 bool Type::canLosslesslyBitCastTo(Type *Ty) const {
00066   // Identity cast means no change so return true
00067   if (this == Ty) 
00068     return true;
00069   
00070   // They are not convertible unless they are at least first class types
00071   if (!this->isFirstClassType() || !Ty->isFirstClassType())
00072     return false;
00073 
00074   // Vector -> Vector conversions are always lossless if the two vector types
00075   // have the same size, otherwise not.  Also, 64-bit vector types can be
00076   // converted to x86mmx.
00077   if (const VectorType *thisPTy = dyn_cast<VectorType>(this)) {
00078     if (const VectorType *thatPTy = dyn_cast<VectorType>(Ty))
00079       return thisPTy->getBitWidth() == thatPTy->getBitWidth();
00080     if (Ty->getTypeID() == Type::X86_MMXTyID &&
00081         thisPTy->getBitWidth() == 64)
00082       return true;
00083   }
00084 
00085   if (this->getTypeID() == Type::X86_MMXTyID)
00086     if (const VectorType *thatPTy = dyn_cast<VectorType>(Ty))
00087       if (thatPTy->getBitWidth() == 64)
00088         return true;
00089 
00090   // At this point we have only various mismatches of the first class types
00091   // remaining and ptr->ptr. Just select the lossless conversions. Everything
00092   // else is not lossless. Conservatively assume we can't losslessly convert
00093   // between pointers with different address spaces.
00094   if (const PointerType *PTy = dyn_cast<PointerType>(this)) {
00095     if (const PointerType *OtherPTy = dyn_cast<PointerType>(Ty))
00096       return PTy->getAddressSpace() == OtherPTy->getAddressSpace();
00097     return false;
00098   }
00099   return false;  // Other types have no identity values
00100 }
00101 
00102 bool Type::isEmptyTy() const {
00103   const ArrayType *ATy = dyn_cast<ArrayType>(this);
00104   if (ATy) {
00105     unsigned NumElements = ATy->getNumElements();
00106     return NumElements == 0 || ATy->getElementType()->isEmptyTy();
00107   }
00108 
00109   const StructType *STy = dyn_cast<StructType>(this);
00110   if (STy) {
00111     unsigned NumElements = STy->getNumElements();
00112     for (unsigned i = 0; i < NumElements; ++i)
00113       if (!STy->getElementType(i)->isEmptyTy())
00114         return false;
00115     return true;
00116   }
00117 
00118   return false;
00119 }
00120 
00121 unsigned Type::getPrimitiveSizeInBits() const {
00122   switch (getTypeID()) {
00123   case Type::HalfTyID: return 16;
00124   case Type::FloatTyID: return 32;
00125   case Type::DoubleTyID: return 64;
00126   case Type::X86_FP80TyID: return 80;
00127   case Type::FP128TyID: return 128;
00128   case Type::PPC_FP128TyID: return 128;
00129   case Type::X86_MMXTyID: return 64;
00130   case Type::IntegerTyID: return cast<IntegerType>(this)->getBitWidth();
00131   case Type::VectorTyID:  return cast<VectorType>(this)->getBitWidth();
00132   default: return 0;
00133   }
00134 }
00135 
00136 /// getScalarSizeInBits - If this is a vector type, return the
00137 /// getPrimitiveSizeInBits value for the element type. Otherwise return the
00138 /// getPrimitiveSizeInBits value for this type.
00139 unsigned Type::getScalarSizeInBits() const {
00140   return getScalarType()->getPrimitiveSizeInBits();
00141 }
00142 
00143 /// getFPMantissaWidth - Return the width of the mantissa of this type.  This
00144 /// is only valid on floating point types.  If the FP type does not
00145 /// have a stable mantissa (e.g. ppc long double), this method returns -1.
00146 int Type::getFPMantissaWidth() const {
00147   if (const VectorType *VTy = dyn_cast<VectorType>(this))
00148     return VTy->getElementType()->getFPMantissaWidth();
00149   assert(isFloatingPointTy() && "Not a floating point type!");
00150   if (getTypeID() == HalfTyID) return 11;
00151   if (getTypeID() == FloatTyID) return 24;
00152   if (getTypeID() == DoubleTyID) return 53;
00153   if (getTypeID() == X86_FP80TyID) return 64;
00154   if (getTypeID() == FP128TyID) return 113;
00155   assert(getTypeID() == PPC_FP128TyID && "unknown fp type");
00156   return -1;
00157 }
00158 
00159 /// isSizedDerivedType - Derived types like structures and arrays are sized
00160 /// iff all of the members of the type are sized as well.  Since asking for
00161 /// their size is relatively uncommon, move this operation out of line.
00162 bool Type::isSizedDerivedType(SmallPtrSetImpl<const Type*> *Visited) const {
00163   if (const ArrayType *ATy = dyn_cast<ArrayType>(this))
00164     return ATy->getElementType()->isSized(Visited);
00165 
00166   if (const VectorType *VTy = dyn_cast<VectorType>(this))
00167     return VTy->getElementType()->isSized(Visited);
00168 
00169   return cast<StructType>(this)->isSized(Visited);
00170 }
00171 
00172 //===----------------------------------------------------------------------===//
00173 //                         Subclass Helper Methods
00174 //===----------------------------------------------------------------------===//
00175 
00176 unsigned Type::getIntegerBitWidth() const {
00177   return cast<IntegerType>(this)->getBitWidth();
00178 }
00179 
00180 bool Type::isFunctionVarArg() const {
00181   return cast<FunctionType>(this)->isVarArg();
00182 }
00183 
00184 Type *Type::getFunctionParamType(unsigned i) const {
00185   return cast<FunctionType>(this)->getParamType(i);
00186 }
00187 
00188 unsigned Type::getFunctionNumParams() const {
00189   return cast<FunctionType>(this)->getNumParams();
00190 }
00191 
00192 StringRef Type::getStructName() const {
00193   return cast<StructType>(this)->getName();
00194 }
00195 
00196 unsigned Type::getStructNumElements() const {
00197   return cast<StructType>(this)->getNumElements();
00198 }
00199 
00200 Type *Type::getStructElementType(unsigned N) const {
00201   return cast<StructType>(this)->getElementType(N);
00202 }
00203 
00204 Type *Type::getSequentialElementType() const {
00205   return cast<SequentialType>(this)->getElementType();
00206 }
00207 
00208 uint64_t Type::getArrayNumElements() const {
00209   return cast<ArrayType>(this)->getNumElements();
00210 }
00211 
00212 unsigned Type::getVectorNumElements() const {
00213   return cast<VectorType>(this)->getNumElements();
00214 }
00215 
00216 unsigned Type::getPointerAddressSpace() const {
00217   return cast<PointerType>(getScalarType())->getAddressSpace();
00218 }
00219 
00220 
00221 //===----------------------------------------------------------------------===//
00222 //                          Primitive 'Type' data
00223 //===----------------------------------------------------------------------===//
00224 
00225 Type *Type::getVoidTy(LLVMContext &C) { return &C.pImpl->VoidTy; }
00226 Type *Type::getLabelTy(LLVMContext &C) { return &C.pImpl->LabelTy; }
00227 Type *Type::getHalfTy(LLVMContext &C) { return &C.pImpl->HalfTy; }
00228 Type *Type::getFloatTy(LLVMContext &C) { return &C.pImpl->FloatTy; }
00229 Type *Type::getDoubleTy(LLVMContext &C) { return &C.pImpl->DoubleTy; }
00230 Type *Type::getMetadataTy(LLVMContext &C) { return &C.pImpl->MetadataTy; }
00231 Type *Type::getX86_FP80Ty(LLVMContext &C) { return &C.pImpl->X86_FP80Ty; }
00232 Type *Type::getFP128Ty(LLVMContext &C) { return &C.pImpl->FP128Ty; }
00233 Type *Type::getPPC_FP128Ty(LLVMContext &C) { return &C.pImpl->PPC_FP128Ty; }
00234 Type *Type::getX86_MMXTy(LLVMContext &C) { return &C.pImpl->X86_MMXTy; }
00235 
00236 IntegerType *Type::getInt1Ty(LLVMContext &C) { return &C.pImpl->Int1Ty; }
00237 IntegerType *Type::getInt8Ty(LLVMContext &C) { return &C.pImpl->Int8Ty; }
00238 IntegerType *Type::getInt16Ty(LLVMContext &C) { return &C.pImpl->Int16Ty; }
00239 IntegerType *Type::getInt32Ty(LLVMContext &C) { return &C.pImpl->Int32Ty; }
00240 IntegerType *Type::getInt64Ty(LLVMContext &C) { return &C.pImpl->Int64Ty; }
00241 
00242 IntegerType *Type::getIntNTy(LLVMContext &C, unsigned N) {
00243   return IntegerType::get(C, N);
00244 }
00245 
00246 PointerType *Type::getHalfPtrTy(LLVMContext &C, unsigned AS) {
00247   return getHalfTy(C)->getPointerTo(AS);
00248 }
00249 
00250 PointerType *Type::getFloatPtrTy(LLVMContext &C, unsigned AS) {
00251   return getFloatTy(C)->getPointerTo(AS);
00252 }
00253 
00254 PointerType *Type::getDoublePtrTy(LLVMContext &C, unsigned AS) {
00255   return getDoubleTy(C)->getPointerTo(AS);
00256 }
00257 
00258 PointerType *Type::getX86_FP80PtrTy(LLVMContext &C, unsigned AS) {
00259   return getX86_FP80Ty(C)->getPointerTo(AS);
00260 }
00261 
00262 PointerType *Type::getFP128PtrTy(LLVMContext &C, unsigned AS) {
00263   return getFP128Ty(C)->getPointerTo(AS);
00264 }
00265 
00266 PointerType *Type::getPPC_FP128PtrTy(LLVMContext &C, unsigned AS) {
00267   return getPPC_FP128Ty(C)->getPointerTo(AS);
00268 }
00269 
00270 PointerType *Type::getX86_MMXPtrTy(LLVMContext &C, unsigned AS) {
00271   return getX86_MMXTy(C)->getPointerTo(AS);
00272 }
00273 
00274 PointerType *Type::getIntNPtrTy(LLVMContext &C, unsigned N, unsigned AS) {
00275   return getIntNTy(C, N)->getPointerTo(AS);
00276 }
00277 
00278 PointerType *Type::getInt1PtrTy(LLVMContext &C, unsigned AS) {
00279   return getInt1Ty(C)->getPointerTo(AS);
00280 }
00281 
00282 PointerType *Type::getInt8PtrTy(LLVMContext &C, unsigned AS) {
00283   return getInt8Ty(C)->getPointerTo(AS);
00284 }
00285 
00286 PointerType *Type::getInt16PtrTy(LLVMContext &C, unsigned AS) {
00287   return getInt16Ty(C)->getPointerTo(AS);
00288 }
00289 
00290 PointerType *Type::getInt32PtrTy(LLVMContext &C, unsigned AS) {
00291   return getInt32Ty(C)->getPointerTo(AS);
00292 }
00293 
00294 PointerType *Type::getInt64PtrTy(LLVMContext &C, unsigned AS) {
00295   return getInt64Ty(C)->getPointerTo(AS);
00296 }
00297 
00298 
00299 //===----------------------------------------------------------------------===//
00300 //                       IntegerType Implementation
00301 //===----------------------------------------------------------------------===//
00302 
00303 IntegerType *IntegerType::get(LLVMContext &C, unsigned NumBits) {
00304   assert(NumBits >= MIN_INT_BITS && "bitwidth too small");
00305   assert(NumBits <= MAX_INT_BITS && "bitwidth too large");
00306   
00307   // Check for the built-in integer types
00308   switch (NumBits) {
00309   case  1: return cast<IntegerType>(Type::getInt1Ty(C));
00310   case  8: return cast<IntegerType>(Type::getInt8Ty(C));
00311   case 16: return cast<IntegerType>(Type::getInt16Ty(C));
00312   case 32: return cast<IntegerType>(Type::getInt32Ty(C));
00313   case 64: return cast<IntegerType>(Type::getInt64Ty(C));
00314   default: 
00315     break;
00316   }
00317   
00318   IntegerType *&Entry = C.pImpl->IntegerTypes[NumBits];
00319 
00320   if (!Entry)
00321     Entry = new (C.pImpl->TypeAllocator) IntegerType(C, NumBits);
00322   
00323   return Entry;
00324 }
00325 
00326 bool IntegerType::isPowerOf2ByteWidth() const {
00327   unsigned BitWidth = getBitWidth();
00328   return (BitWidth > 7) && isPowerOf2_32(BitWidth);
00329 }
00330 
00331 APInt IntegerType::getMask() const {
00332   return APInt::getAllOnesValue(getBitWidth());
00333 }
00334 
00335 //===----------------------------------------------------------------------===//
00336 //                       FunctionType Implementation
00337 //===----------------------------------------------------------------------===//
00338 
00339 FunctionType::FunctionType(Type *Result, ArrayRef<Type*> Params,
00340                            bool IsVarArgs)
00341   : Type(Result->getContext(), FunctionTyID) {
00342   Type **SubTys = reinterpret_cast<Type**>(this+1);
00343   assert(isValidReturnType(Result) && "invalid return type for function");
00344   setSubclassData(IsVarArgs);
00345 
00346   SubTys[0] = const_cast<Type*>(Result);
00347 
00348   for (unsigned i = 0, e = Params.size(); i != e; ++i) {
00349     assert(isValidArgumentType(Params[i]) &&
00350            "Not a valid type for function argument!");
00351     SubTys[i+1] = Params[i];
00352   }
00353 
00354   ContainedTys = SubTys;
00355   NumContainedTys = Params.size() + 1; // + 1 for result type
00356 }
00357 
00358 // FunctionType::get - The factory function for the FunctionType class.
00359 FunctionType *FunctionType::get(Type *ReturnType,
00360                                 ArrayRef<Type*> Params, bool isVarArg) {
00361   LLVMContextImpl *pImpl = ReturnType->getContext().pImpl;
00362   FunctionTypeKeyInfo::KeyTy Key(ReturnType, Params, isVarArg);
00363   LLVMContextImpl::FunctionTypeMap::iterator I =
00364     pImpl->FunctionTypes.find_as(Key);
00365   FunctionType *FT;
00366 
00367   if (I == pImpl->FunctionTypes.end()) {
00368     FT = (FunctionType*) pImpl->TypeAllocator.
00369       Allocate(sizeof(FunctionType) + sizeof(Type*) * (Params.size() + 1),
00370                AlignOf<FunctionType>::Alignment);
00371     new (FT) FunctionType(ReturnType, Params, isVarArg);
00372     pImpl->FunctionTypes[FT] = true;
00373   } else {
00374     FT = I->first;
00375   }
00376 
00377   return FT;
00378 }
00379 
00380 FunctionType *FunctionType::get(Type *Result, bool isVarArg) {
00381   return get(Result, None, isVarArg);
00382 }
00383 
00384 /// isValidReturnType - Return true if the specified type is valid as a return
00385 /// type.
00386 bool FunctionType::isValidReturnType(Type *RetTy) {
00387   return !RetTy->isFunctionTy() && !RetTy->isLabelTy() &&
00388   !RetTy->isMetadataTy();
00389 }
00390 
00391 /// isValidArgumentType - Return true if the specified type is valid as an
00392 /// argument type.
00393 bool FunctionType::isValidArgumentType(Type *ArgTy) {
00394   return ArgTy->isFirstClassType();
00395 }
00396 
00397 //===----------------------------------------------------------------------===//
00398 //                       StructType Implementation
00399 //===----------------------------------------------------------------------===//
00400 
00401 // Primitive Constructors.
00402 
00403 StructType *StructType::get(LLVMContext &Context, ArrayRef<Type*> ETypes, 
00404                             bool isPacked) {
00405   LLVMContextImpl *pImpl = Context.pImpl;
00406   AnonStructTypeKeyInfo::KeyTy Key(ETypes, isPacked);
00407   LLVMContextImpl::StructTypeMap::iterator I =
00408     pImpl->AnonStructTypes.find_as(Key);
00409   StructType *ST;
00410 
00411   if (I == pImpl->AnonStructTypes.end()) {
00412     // Value not found.  Create a new type!
00413     ST = new (Context.pImpl->TypeAllocator) StructType(Context);
00414     ST->setSubclassData(SCDB_IsLiteral);  // Literal struct.
00415     ST->setBody(ETypes, isPacked);
00416     Context.pImpl->AnonStructTypes[ST] = true;
00417   } else {
00418     ST = I->first;
00419   }
00420 
00421   return ST;
00422 }
00423 
00424 void StructType::setBody(ArrayRef<Type*> Elements, bool isPacked) {
00425   assert(isOpaque() && "Struct body already set!");
00426   
00427   setSubclassData(getSubclassData() | SCDB_HasBody);
00428   if (isPacked)
00429     setSubclassData(getSubclassData() | SCDB_Packed);
00430 
00431   unsigned NumElements = Elements.size();
00432   Type **Elts = getContext().pImpl->TypeAllocator.Allocate<Type*>(NumElements);
00433   memcpy(Elts, Elements.data(), sizeof(Elements[0]) * NumElements);
00434   
00435   ContainedTys = Elts;
00436   NumContainedTys = NumElements;
00437 }
00438 
00439 void StructType::setName(StringRef Name) {
00440   if (Name == getName()) return;
00441 
00442   StringMap<StructType *> &SymbolTable = getContext().pImpl->NamedStructTypes;
00443   typedef StringMap<StructType *>::MapEntryTy EntryTy;
00444 
00445   // If this struct already had a name, remove its symbol table entry. Don't
00446   // delete the data yet because it may be part of the new name.
00447   if (SymbolTableEntry)
00448     SymbolTable.remove((EntryTy *)SymbolTableEntry);
00449 
00450   // If this is just removing the name, we're done.
00451   if (Name.empty()) {
00452     if (SymbolTableEntry) {
00453       // Delete the old string data.
00454       ((EntryTy *)SymbolTableEntry)->Destroy(SymbolTable.getAllocator());
00455       SymbolTableEntry = nullptr;
00456     }
00457     return;
00458   }
00459   
00460   // Look up the entry for the name.
00461   auto IterBool =
00462       getContext().pImpl->NamedStructTypes.insert(std::make_pair(Name, this));
00463 
00464   // While we have a name collision, try a random rename.
00465   if (!IterBool.second) {
00466     SmallString<64> TempStr(Name);
00467     TempStr.push_back('.');
00468     raw_svector_ostream TmpStream(TempStr);
00469     unsigned NameSize = Name.size();
00470    
00471     do {
00472       TempStr.resize(NameSize + 1);
00473       TmpStream.resync();
00474       TmpStream << getContext().pImpl->NamedStructTypesUniqueID++;
00475 
00476       IterBool = getContext().pImpl->NamedStructTypes.insert(
00477           std::make_pair(TmpStream.str(), this));
00478     } while (!IterBool.second);
00479   }
00480 
00481   // Delete the old string data.
00482   if (SymbolTableEntry)
00483     ((EntryTy *)SymbolTableEntry)->Destroy(SymbolTable.getAllocator());
00484   SymbolTableEntry = &*IterBool.first;
00485 }
00486 
00487 //===----------------------------------------------------------------------===//
00488 // StructType Helper functions.
00489 
00490 StructType *StructType::create(LLVMContext &Context, StringRef Name) {
00491   StructType *ST = new (Context.pImpl->TypeAllocator) StructType(Context);
00492   if (!Name.empty())
00493     ST->setName(Name);
00494   return ST;
00495 }
00496 
00497 StructType *StructType::get(LLVMContext &Context, bool isPacked) {
00498   return get(Context, None, isPacked);
00499 }
00500 
00501 StructType *StructType::get(Type *type, ...) {
00502   assert(type && "Cannot create a struct type with no elements with this");
00503   LLVMContext &Ctx = type->getContext();
00504   va_list ap;
00505   SmallVector<llvm::Type*, 8> StructFields;
00506   va_start(ap, type);
00507   while (type) {
00508     StructFields.push_back(type);
00509     type = va_arg(ap, llvm::Type*);
00510   }
00511   auto *Ret = llvm::StructType::get(Ctx, StructFields);
00512   va_end(ap);
00513   return Ret;
00514 }
00515 
00516 StructType *StructType::create(LLVMContext &Context, ArrayRef<Type*> Elements,
00517                                StringRef Name, bool isPacked) {
00518   StructType *ST = create(Context, Name);
00519   ST->setBody(Elements, isPacked);
00520   return ST;
00521 }
00522 
00523 StructType *StructType::create(LLVMContext &Context, ArrayRef<Type*> Elements) {
00524   return create(Context, Elements, StringRef());
00525 }
00526 
00527 StructType *StructType::create(LLVMContext &Context) {
00528   return create(Context, StringRef());
00529 }
00530 
00531 StructType *StructType::create(ArrayRef<Type*> Elements, StringRef Name,
00532                                bool isPacked) {
00533   assert(!Elements.empty() &&
00534          "This method may not be invoked with an empty list");
00535   return create(Elements[0]->getContext(), Elements, Name, isPacked);
00536 }
00537 
00538 StructType *StructType::create(ArrayRef<Type*> Elements) {
00539   assert(!Elements.empty() &&
00540          "This method may not be invoked with an empty list");
00541   return create(Elements[0]->getContext(), Elements, StringRef());
00542 }
00543 
00544 StructType *StructType::create(StringRef Name, Type *type, ...) {
00545   assert(type && "Cannot create a struct type with no elements with this");
00546   LLVMContext &Ctx = type->getContext();
00547   va_list ap;
00548   SmallVector<llvm::Type*, 8> StructFields;
00549   va_start(ap, type);
00550   while (type) {
00551     StructFields.push_back(type);
00552     type = va_arg(ap, llvm::Type*);
00553   }
00554   auto *Ret = llvm::StructType::create(Ctx, StructFields, Name);
00555   va_end(ap);
00556   return Ret;
00557 }
00558 
00559 bool StructType::isSized(SmallPtrSetImpl<const Type*> *Visited) const {
00560   if ((getSubclassData() & SCDB_IsSized) != 0)
00561     return true;
00562   if (isOpaque())
00563     return false;
00564 
00565   if (Visited && !Visited->insert(this).second)
00566     return false;
00567 
00568   // Okay, our struct is sized if all of the elements are, but if one of the
00569   // elements is opaque, the struct isn't sized *yet*, but may become sized in
00570   // the future, so just bail out without caching.
00571   for (element_iterator I = element_begin(), E = element_end(); I != E; ++I)
00572     if (!(*I)->isSized(Visited))
00573       return false;
00574 
00575   // Here we cheat a bit and cast away const-ness. The goal is to memoize when
00576   // we find a sized type, as types can only move from opaque to sized, not the
00577   // other way.
00578   const_cast<StructType*>(this)->setSubclassData(
00579     getSubclassData() | SCDB_IsSized);
00580   return true;
00581 }
00582 
00583 StringRef StructType::getName() const {
00584   assert(!isLiteral() && "Literal structs never have names");
00585   if (!SymbolTableEntry) return StringRef();
00586 
00587   return ((StringMapEntry<StructType*> *)SymbolTableEntry)->getKey();
00588 }
00589 
00590 void StructType::setBody(Type *type, ...) {
00591   assert(type && "Cannot create a struct type with no elements with this");
00592   va_list ap;
00593   SmallVector<llvm::Type*, 8> StructFields;
00594   va_start(ap, type);
00595   while (type) {
00596     StructFields.push_back(type);
00597     type = va_arg(ap, llvm::Type*);
00598   }
00599   setBody(StructFields);
00600   va_end(ap);
00601 }
00602 
00603 bool StructType::isValidElementType(Type *ElemTy) {
00604   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
00605          !ElemTy->isMetadataTy() && !ElemTy->isFunctionTy();
00606 }
00607 
00608 /// isLayoutIdentical - Return true if this is layout identical to the
00609 /// specified struct.
00610 bool StructType::isLayoutIdentical(StructType *Other) const {
00611   if (this == Other) return true;
00612   
00613   if (isPacked() != Other->isPacked() ||
00614       getNumElements() != Other->getNumElements())
00615     return false;
00616   
00617   return std::equal(element_begin(), element_end(), Other->element_begin());
00618 }
00619 
00620 /// getTypeByName - Return the type with the specified name, or null if there
00621 /// is none by that name.
00622 StructType *Module::getTypeByName(StringRef Name) const {
00623   return getContext().pImpl->NamedStructTypes.lookup(Name);
00624 }
00625 
00626 
00627 //===----------------------------------------------------------------------===//
00628 //                       CompositeType Implementation
00629 //===----------------------------------------------------------------------===//
00630 
00631 Type *CompositeType::getTypeAtIndex(const Value *V) {
00632   if (StructType *STy = dyn_cast<StructType>(this)) {
00633     unsigned Idx =
00634       (unsigned)cast<Constant>(V)->getUniqueInteger().getZExtValue();
00635     assert(indexValid(Idx) && "Invalid structure index!");
00636     return STy->getElementType(Idx);
00637   }
00638 
00639   return cast<SequentialType>(this)->getElementType();
00640 }
00641 Type *CompositeType::getTypeAtIndex(unsigned Idx) {
00642   if (StructType *STy = dyn_cast<StructType>(this)) {
00643     assert(indexValid(Idx) && "Invalid structure index!");
00644     return STy->getElementType(Idx);
00645   }
00646   
00647   return cast<SequentialType>(this)->getElementType();
00648 }
00649 bool CompositeType::indexValid(const Value *V) const {
00650   if (const StructType *STy = dyn_cast<StructType>(this)) {
00651     // Structure indexes require (vectors of) 32-bit integer constants.  In the
00652     // vector case all of the indices must be equal.
00653     if (!V->getType()->getScalarType()->isIntegerTy(32))
00654       return false;
00655     const Constant *C = dyn_cast<Constant>(V);
00656     if (C && V->getType()->isVectorTy())
00657       C = C->getSplatValue();
00658     const ConstantInt *CU = dyn_cast_or_null<ConstantInt>(C);
00659     return CU && CU->getZExtValue() < STy->getNumElements();
00660   }
00661 
00662   // Sequential types can be indexed by any integer.
00663   return V->getType()->isIntOrIntVectorTy();
00664 }
00665 
00666 bool CompositeType::indexValid(unsigned Idx) const {
00667   if (const StructType *STy = dyn_cast<StructType>(this))
00668     return Idx < STy->getNumElements();
00669   // Sequential types can be indexed by any integer.
00670   return true;
00671 }
00672 
00673 
00674 //===----------------------------------------------------------------------===//
00675 //                           ArrayType Implementation
00676 //===----------------------------------------------------------------------===//
00677 
00678 ArrayType::ArrayType(Type *ElType, uint64_t NumEl)
00679   : SequentialType(ArrayTyID, ElType) {
00680   NumElements = NumEl;
00681 }
00682 
00683 ArrayType *ArrayType::get(Type *elementType, uint64_t NumElements) {
00684   Type *ElementType = const_cast<Type*>(elementType);
00685   assert(isValidElementType(ElementType) && "Invalid type for array element!");
00686     
00687   LLVMContextImpl *pImpl = ElementType->getContext().pImpl;
00688   ArrayType *&Entry = 
00689     pImpl->ArrayTypes[std::make_pair(ElementType, NumElements)];
00690 
00691   if (!Entry)
00692     Entry = new (pImpl->TypeAllocator) ArrayType(ElementType, NumElements);
00693   return Entry;
00694 }
00695 
00696 bool ArrayType::isValidElementType(Type *ElemTy) {
00697   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
00698          !ElemTy->isMetadataTy() && !ElemTy->isFunctionTy();
00699 }
00700 
00701 //===----------------------------------------------------------------------===//
00702 //                          VectorType Implementation
00703 //===----------------------------------------------------------------------===//
00704 
00705 VectorType::VectorType(Type *ElType, unsigned NumEl)
00706   : SequentialType(VectorTyID, ElType) {
00707   NumElements = NumEl;
00708 }
00709 
00710 VectorType *VectorType::get(Type *elementType, unsigned NumElements) {
00711   Type *ElementType = const_cast<Type*>(elementType);
00712   assert(NumElements > 0 && "#Elements of a VectorType must be greater than 0");
00713   assert(isValidElementType(ElementType) &&
00714          "Elements of a VectorType must be a primitive type");
00715   
00716   LLVMContextImpl *pImpl = ElementType->getContext().pImpl;
00717   VectorType *&Entry = ElementType->getContext().pImpl
00718     ->VectorTypes[std::make_pair(ElementType, NumElements)];
00719 
00720   if (!Entry)
00721     Entry = new (pImpl->TypeAllocator) VectorType(ElementType, NumElements);
00722   return Entry;
00723 }
00724 
00725 bool VectorType::isValidElementType(Type *ElemTy) {
00726   return ElemTy->isIntegerTy() || ElemTy->isFloatingPointTy() ||
00727     ElemTy->isPointerTy();
00728 }
00729 
00730 //===----------------------------------------------------------------------===//
00731 //                         PointerType Implementation
00732 //===----------------------------------------------------------------------===//
00733 
00734 PointerType *PointerType::get(Type *EltTy, unsigned AddressSpace) {
00735   assert(EltTy && "Can't get a pointer to <null> type!");
00736   assert(isValidElementType(EltTy) && "Invalid type for pointer element!");
00737   
00738   LLVMContextImpl *CImpl = EltTy->getContext().pImpl;
00739   
00740   // Since AddressSpace #0 is the common case, we special case it.
00741   PointerType *&Entry = AddressSpace == 0 ? CImpl->PointerTypes[EltTy]
00742      : CImpl->ASPointerTypes[std::make_pair(EltTy, AddressSpace)];
00743 
00744   if (!Entry)
00745     Entry = new (CImpl->TypeAllocator) PointerType(EltTy, AddressSpace);
00746   return Entry;
00747 }
00748 
00749 
00750 PointerType::PointerType(Type *E, unsigned AddrSpace)
00751   : SequentialType(PointerTyID, E) {
00752 #ifndef NDEBUG
00753   const unsigned oldNCT = NumContainedTys;
00754 #endif
00755   setSubclassData(AddrSpace);
00756   // Check for miscompile. PR11652.
00757   assert(oldNCT == NumContainedTys && "bitfield written out of bounds?");
00758 }
00759 
00760 PointerType *Type::getPointerTo(unsigned addrs) {
00761   return PointerType::get(this, addrs);
00762 }
00763 
00764 bool PointerType::isValidElementType(Type *ElemTy) {
00765   return !ElemTy->isVoidTy() && !ElemTy->isLabelTy() &&
00766          !ElemTy->isMetadataTy();
00767 }