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-rw-r--r--lib/IR/Function.cpp665
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diff --git a/lib/IR/Function.cpp b/lib/IR/Function.cpp
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+//===-- Function.cpp - Implement the Global object classes ----------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the Function class for the IR library.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Function.h"
+#include "SymbolTableListTraitsImpl.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringExtras.h"
+#include "llvm/CodeGen/ValueTypes.h"
+#include "llvm/DerivedTypes.h"
+#include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
+#include "llvm/Module.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/Support/InstIterator.h"
+#include "llvm/Support/LeakDetector.h"
+#include "llvm/Support/ManagedStatic.h"
+#include "llvm/Support/RWMutex.h"
+#include "llvm/Support/StringPool.h"
+#include "llvm/Support/Threading.h"
+using namespace llvm;
+
+// Explicit instantiations of SymbolTableListTraits since some of the methods
+// are not in the public header file...
+template class llvm::SymbolTableListTraits<Argument, Function>;
+template class llvm::SymbolTableListTraits<BasicBlock, Function>;
+
+//===----------------------------------------------------------------------===//
+// Argument Implementation
+//===----------------------------------------------------------------------===//
+
+void Argument::anchor() { }
+
+Argument::Argument(Type *Ty, const Twine &Name, Function *Par)
+ : Value(Ty, Value::ArgumentVal) {
+ Parent = 0;
+
+ // Make sure that we get added to a function
+ LeakDetector::addGarbageObject(this);
+
+ if (Par)
+ Par->getArgumentList().push_back(this);
+ setName(Name);
+}
+
+void Argument::setParent(Function *parent) {
+ if (getParent())
+ LeakDetector::addGarbageObject(this);
+ Parent = parent;
+ if (getParent())
+ LeakDetector::removeGarbageObject(this);
+}
+
+/// getArgNo - Return the index of this formal argument in its containing
+/// function. For example in "void foo(int a, float b)" a is 0 and b is 1.
+unsigned Argument::getArgNo() const {
+ const Function *F = getParent();
+ assert(F && "Argument is not in a function");
+
+ Function::const_arg_iterator AI = F->arg_begin();
+ unsigned ArgIdx = 0;
+ for (; &*AI != this; ++AI)
+ ++ArgIdx;
+
+ return ArgIdx;
+}
+
+/// hasByValAttr - Return true if this argument has the byval attribute on it
+/// in its containing function.
+bool Argument::hasByValAttr() const {
+ if (!getType()->isPointerTy()) return false;
+ return getParent()->getAttributes().
+ hasAttribute(getArgNo()+1, Attribute::ByVal);
+}
+
+unsigned Argument::getParamAlignment() const {
+ assert(getType()->isPointerTy() && "Only pointers have alignments");
+ return getParent()->getParamAlignment(getArgNo()+1);
+
+}
+
+/// hasNestAttr - Return true if this argument has the nest attribute on
+/// it in its containing function.
+bool Argument::hasNestAttr() const {
+ if (!getType()->isPointerTy()) return false;
+ return getParent()->getAttributes().
+ hasAttribute(getArgNo()+1, Attribute::Nest);
+}
+
+/// hasNoAliasAttr - Return true if this argument has the noalias attribute on
+/// it in its containing function.
+bool Argument::hasNoAliasAttr() const {
+ if (!getType()->isPointerTy()) return false;
+ return getParent()->getAttributes().
+ hasAttribute(getArgNo()+1, Attribute::NoAlias);
+}
+
+/// hasNoCaptureAttr - Return true if this argument has the nocapture attribute
+/// on it in its containing function.
+bool Argument::hasNoCaptureAttr() const {
+ if (!getType()->isPointerTy()) return false;
+ return getParent()->getAttributes().
+ hasAttribute(getArgNo()+1, Attribute::NoCapture);
+}
+
+/// hasSRetAttr - Return true if this argument has the sret attribute on
+/// it in its containing function.
+bool Argument::hasStructRetAttr() const {
+ if (!getType()->isPointerTy()) return false;
+ if (this != getParent()->arg_begin())
+ return false; // StructRet param must be first param
+ return getParent()->getAttributes().
+ hasAttribute(1, Attribute::StructRet);
+}
+
+/// addAttr - Add a Attribute to an argument
+void Argument::addAttr(Attribute attr) {
+ getParent()->addAttribute(getArgNo() + 1, attr);
+}
+
+/// removeAttr - Remove a Attribute from an argument
+void Argument::removeAttr(Attribute attr) {
+ getParent()->removeAttribute(getArgNo() + 1, attr);
+}
+
+
+//===----------------------------------------------------------------------===//
+// Helper Methods in Function
+//===----------------------------------------------------------------------===//
+
+LLVMContext &Function::getContext() const {
+ return getType()->getContext();
+}
+
+FunctionType *Function::getFunctionType() const {
+ return cast<FunctionType>(getType()->getElementType());
+}
+
+bool Function::isVarArg() const {
+ return getFunctionType()->isVarArg();
+}
+
+Type *Function::getReturnType() const {
+ return getFunctionType()->getReturnType();
+}
+
+void Function::removeFromParent() {
+ getParent()->getFunctionList().remove(this);
+}
+
+void Function::eraseFromParent() {
+ getParent()->getFunctionList().erase(this);
+}
+
+//===----------------------------------------------------------------------===//
+// Function Implementation
+//===----------------------------------------------------------------------===//
+
+Function::Function(FunctionType *Ty, LinkageTypes Linkage,
+ const Twine &name, Module *ParentModule)
+ : GlobalValue(PointerType::getUnqual(Ty),
+ Value::FunctionVal, 0, 0, Linkage, name) {
+ assert(FunctionType::isValidReturnType(getReturnType()) &&
+ "invalid return type");
+ SymTab = new ValueSymbolTable();
+
+ // If the function has arguments, mark them as lazily built.
+ if (Ty->getNumParams())
+ setValueSubclassData(1); // Set the "has lazy arguments" bit.
+
+ // Make sure that we get added to a function
+ LeakDetector::addGarbageObject(this);
+
+ if (ParentModule)
+ ParentModule->getFunctionList().push_back(this);
+
+ // Ensure intrinsics have the right parameter attributes.
+ if (unsigned IID = getIntrinsicID())
+ setAttributes(Intrinsic::getAttributes(getContext(), Intrinsic::ID(IID)));
+
+}
+
+Function::~Function() {
+ dropAllReferences(); // After this it is safe to delete instructions.
+
+ // Delete all of the method arguments and unlink from symbol table...
+ ArgumentList.clear();
+ delete SymTab;
+
+ // Remove the function from the on-the-side GC table.
+ clearGC();
+}
+
+void Function::BuildLazyArguments() const {
+ // Create the arguments vector, all arguments start out unnamed.
+ FunctionType *FT = getFunctionType();
+ for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i) {
+ assert(!FT->getParamType(i)->isVoidTy() &&
+ "Cannot have void typed arguments!");
+ ArgumentList.push_back(new Argument(FT->getParamType(i)));
+ }
+
+ // Clear the lazy arguments bit.
+ unsigned SDC = getSubclassDataFromValue();
+ const_cast<Function*>(this)->setValueSubclassData(SDC &= ~1);
+}
+
+size_t Function::arg_size() const {
+ return getFunctionType()->getNumParams();
+}
+bool Function::arg_empty() const {
+ return getFunctionType()->getNumParams() == 0;
+}
+
+void Function::setParent(Module *parent) {
+ if (getParent())
+ LeakDetector::addGarbageObject(this);
+ Parent = parent;
+ if (getParent())
+ LeakDetector::removeGarbageObject(this);
+}
+
+// dropAllReferences() - This function causes all the subinstructions to "let
+// go" of all references that they are maintaining. This allows one to
+// 'delete' a whole class at a time, even though there may be circular
+// references... first all references are dropped, and all use counts go to
+// zero. Then everything is deleted for real. Note that no operations are
+// valid on an object that has "dropped all references", except operator
+// delete.
+//
+void Function::dropAllReferences() {
+ for (iterator I = begin(), E = end(); I != E; ++I)
+ I->dropAllReferences();
+
+ // Delete all basic blocks. They are now unused, except possibly by
+ // blockaddresses, but BasicBlock's destructor takes care of those.
+ while (!BasicBlocks.empty())
+ BasicBlocks.begin()->eraseFromParent();
+}
+
+void Function::addAttribute(unsigned i, Attribute attr) {
+ AttributeSet PAL = getAttributes();
+ PAL = PAL.addAttr(getContext(), i, attr);
+ setAttributes(PAL);
+}
+
+void Function::removeAttribute(unsigned i, Attribute attr) {
+ AttributeSet PAL = getAttributes();
+ PAL = PAL.removeAttr(getContext(), i, attr);
+ setAttributes(PAL);
+}
+
+// Maintain the GC name for each function in an on-the-side table. This saves
+// allocating an additional word in Function for programs which do not use GC
+// (i.e., most programs) at the cost of increased overhead for clients which do
+// use GC.
+static DenseMap<const Function*,PooledStringPtr> *GCNames;
+static StringPool *GCNamePool;
+static ManagedStatic<sys::SmartRWMutex<true> > GCLock;
+
+bool Function::hasGC() const {
+ sys::SmartScopedReader<true> Reader(*GCLock);
+ return GCNames && GCNames->count(this);
+}
+
+const char *Function::getGC() const {
+ assert(hasGC() && "Function has no collector");
+ sys::SmartScopedReader<true> Reader(*GCLock);
+ return *(*GCNames)[this];
+}
+
+void Function::setGC(const char *Str) {
+ sys::SmartScopedWriter<true> Writer(*GCLock);
+ if (!GCNamePool)
+ GCNamePool = new StringPool();
+ if (!GCNames)
+ GCNames = new DenseMap<const Function*,PooledStringPtr>();
+ (*GCNames)[this] = GCNamePool->intern(Str);
+}
+
+void Function::clearGC() {
+ sys::SmartScopedWriter<true> Writer(*GCLock);
+ if (GCNames) {
+ GCNames->erase(this);
+ if (GCNames->empty()) {
+ delete GCNames;
+ GCNames = 0;
+ if (GCNamePool->empty()) {
+ delete GCNamePool;
+ GCNamePool = 0;
+ }
+ }
+ }
+}
+
+/// copyAttributesFrom - copy all additional attributes (those not needed to
+/// create a Function) from the Function Src to this one.
+void Function::copyAttributesFrom(const GlobalValue *Src) {
+ assert(isa<Function>(Src) && "Expected a Function!");
+ GlobalValue::copyAttributesFrom(Src);
+ const Function *SrcF = cast<Function>(Src);
+ setCallingConv(SrcF->getCallingConv());
+ setAttributes(SrcF->getAttributes());
+ if (SrcF->hasGC())
+ setGC(SrcF->getGC());
+ else
+ clearGC();
+}
+
+/// getIntrinsicID - This method returns the ID number of the specified
+/// function, or Intrinsic::not_intrinsic if the function is not an
+/// intrinsic, or if the pointer is null. This value is always defined to be
+/// zero to allow easy checking for whether a function is intrinsic or not. The
+/// particular intrinsic functions which correspond to this value are defined in
+/// llvm/Intrinsics.h.
+///
+unsigned Function::getIntrinsicID() const {
+ const ValueName *ValName = this->getValueName();
+ if (!ValName || !isIntrinsic())
+ return 0;
+ unsigned Len = ValName->getKeyLength();
+ const char *Name = ValName->getKeyData();
+
+#define GET_FUNCTION_RECOGNIZER
+#include "llvm/Intrinsics.gen"
+#undef GET_FUNCTION_RECOGNIZER
+ return 0;
+}
+
+std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
+ assert(id < num_intrinsics && "Invalid intrinsic ID!");
+ static const char * const Table[] = {
+ "not_intrinsic",
+#define GET_INTRINSIC_NAME_TABLE
+#include "llvm/Intrinsics.gen"
+#undef GET_INTRINSIC_NAME_TABLE
+ };
+ if (Tys.empty())
+ return Table[id];
+ std::string Result(Table[id]);
+ for (unsigned i = 0; i < Tys.size(); ++i) {
+ if (PointerType* PTyp = dyn_cast<PointerType>(Tys[i])) {
+ Result += ".p" + llvm::utostr(PTyp->getAddressSpace()) +
+ EVT::getEVT(PTyp->getElementType()).getEVTString();
+ }
+ else if (Tys[i])
+ Result += "." + EVT::getEVT(Tys[i]).getEVTString();
+ }
+ return Result;
+}
+
+
+/// IIT_Info - These are enumerators that describe the entries returned by the
+/// getIntrinsicInfoTableEntries function.
+///
+/// NOTE: This must be kept in synch with the copy in TblGen/IntrinsicEmitter!
+enum IIT_Info {
+ // Common values should be encoded with 0-15.
+ IIT_Done = 0,
+ IIT_I1 = 1,
+ IIT_I8 = 2,
+ IIT_I16 = 3,
+ IIT_I32 = 4,
+ IIT_I64 = 5,
+ IIT_F32 = 6,
+ IIT_F64 = 7,
+ IIT_V2 = 8,
+ IIT_V4 = 9,
+ IIT_V8 = 10,
+ IIT_V16 = 11,
+ IIT_V32 = 12,
+ IIT_MMX = 13,
+ IIT_PTR = 14,
+ IIT_ARG = 15,
+
+ // Values from 16+ are only encodable with the inefficient encoding.
+ IIT_METADATA = 16,
+ IIT_EMPTYSTRUCT = 17,
+ IIT_STRUCT2 = 18,
+ IIT_STRUCT3 = 19,
+ IIT_STRUCT4 = 20,
+ IIT_STRUCT5 = 21,
+ IIT_EXTEND_VEC_ARG = 22,
+ IIT_TRUNC_VEC_ARG = 23,
+ IIT_ANYPTR = 24
+};
+
+
+static void DecodeIITType(unsigned &NextElt, ArrayRef<unsigned char> Infos,
+ SmallVectorImpl<Intrinsic::IITDescriptor> &OutputTable) {
+ IIT_Info Info = IIT_Info(Infos[NextElt++]);
+ unsigned StructElts = 2;
+ using namespace Intrinsic;
+
+ switch (Info) {
+ case IIT_Done:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Void, 0));
+ return;
+ case IIT_MMX:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::MMX, 0));
+ return;
+ case IIT_METADATA:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Metadata, 0));
+ return;
+ case IIT_F32:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Float, 0));
+ return;
+ case IIT_F64:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Double, 0));
+ return;
+ case IIT_I1:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 1));
+ return;
+ case IIT_I8:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 8));
+ return;
+ case IIT_I16:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer,16));
+ return;
+ case IIT_I32:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 32));
+ return;
+ case IIT_I64:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Integer, 64));
+ return;
+ case IIT_V2:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 2));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_V4:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 4));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_V8:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 8));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_V16:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 16));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_V32:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Vector, 32));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_PTR:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer, 0));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ case IIT_ANYPTR: { // [ANYPTR addrspace, subtype]
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Pointer,
+ Infos[NextElt++]));
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ }
+ case IIT_ARG: {
+ unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Argument, ArgInfo));
+ return;
+ }
+ case IIT_EXTEND_VEC_ARG: {
+ unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::ExtendVecArgument,
+ ArgInfo));
+ return;
+ }
+ case IIT_TRUNC_VEC_ARG: {
+ unsigned ArgInfo = (NextElt == Infos.size() ? 0 : Infos[NextElt++]);
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::TruncVecArgument,
+ ArgInfo));
+ return;
+ }
+ case IIT_EMPTYSTRUCT:
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct, 0));
+ return;
+ case IIT_STRUCT5: ++StructElts; // FALL THROUGH.
+ case IIT_STRUCT4: ++StructElts; // FALL THROUGH.
+ case IIT_STRUCT3: ++StructElts; // FALL THROUGH.
+ case IIT_STRUCT2: {
+ OutputTable.push_back(IITDescriptor::get(IITDescriptor::Struct,StructElts));
+
+ for (unsigned i = 0; i != StructElts; ++i)
+ DecodeIITType(NextElt, Infos, OutputTable);
+ return;
+ }
+ }
+ llvm_unreachable("unhandled");
+}
+
+
+#define GET_INTRINSIC_GENERATOR_GLOBAL
+#include "llvm/Intrinsics.gen"
+#undef GET_INTRINSIC_GENERATOR_GLOBAL
+
+void Intrinsic::getIntrinsicInfoTableEntries(ID id,
+ SmallVectorImpl<IITDescriptor> &T){
+ // Check to see if the intrinsic's type was expressible by the table.
+ unsigned TableVal = IIT_Table[id-1];
+
+ // Decode the TableVal into an array of IITValues.
+ SmallVector<unsigned char, 8> IITValues;
+ ArrayRef<unsigned char> IITEntries;
+ unsigned NextElt = 0;
+ if ((TableVal >> 31) != 0) {
+ // This is an offset into the IIT_LongEncodingTable.
+ IITEntries = IIT_LongEncodingTable;
+
+ // Strip sentinel bit.
+ NextElt = (TableVal << 1) >> 1;
+ } else {
+ // Decode the TableVal into an array of IITValues. If the entry was encoded
+ // into a single word in the table itself, decode it now.
+ do {
+ IITValues.push_back(TableVal & 0xF);
+ TableVal >>= 4;
+ } while (TableVal);
+
+ IITEntries = IITValues;
+ NextElt = 0;
+ }
+
+ // Okay, decode the table into the output vector of IITDescriptors.
+ DecodeIITType(NextElt, IITEntries, T);
+ while (NextElt != IITEntries.size() && IITEntries[NextElt] != 0)
+ DecodeIITType(NextElt, IITEntries, T);
+}
+
+
+static Type *DecodeFixedType(ArrayRef<Intrinsic::IITDescriptor> &Infos,
+ ArrayRef<Type*> Tys, LLVMContext &Context) {
+ using namespace Intrinsic;
+ IITDescriptor D = Infos.front();
+ Infos = Infos.slice(1);
+
+ switch (D.Kind) {
+ case IITDescriptor::Void: return Type::getVoidTy(Context);
+ case IITDescriptor::MMX: return Type::getX86_MMXTy(Context);
+ case IITDescriptor::Metadata: return Type::getMetadataTy(Context);
+ case IITDescriptor::Float: return Type::getFloatTy(Context);
+ case IITDescriptor::Double: return Type::getDoubleTy(Context);
+
+ case IITDescriptor::Integer:
+ return IntegerType::get(Context, D.Integer_Width);
+ case IITDescriptor::Vector:
+ return VectorType::get(DecodeFixedType(Infos, Tys, Context),D.Vector_Width);
+ case IITDescriptor::Pointer:
+ return PointerType::get(DecodeFixedType(Infos, Tys, Context),
+ D.Pointer_AddressSpace);
+ case IITDescriptor::Struct: {
+ Type *Elts[5];
+ assert(D.Struct_NumElements <= 5 && "Can't handle this yet");
+ for (unsigned i = 0, e = D.Struct_NumElements; i != e; ++i)
+ Elts[i] = DecodeFixedType(Infos, Tys, Context);
+ return StructType::get(Context, ArrayRef<Type*>(Elts,D.Struct_NumElements));
+ }
+
+ case IITDescriptor::Argument:
+ return Tys[D.getArgumentNumber()];
+ case IITDescriptor::ExtendVecArgument:
+ return VectorType::getExtendedElementVectorType(cast<VectorType>(
+ Tys[D.getArgumentNumber()]));
+
+ case IITDescriptor::TruncVecArgument:
+ return VectorType::getTruncatedElementVectorType(cast<VectorType>(
+ Tys[D.getArgumentNumber()]));
+ }
+ llvm_unreachable("unhandled");
+}
+
+
+
+FunctionType *Intrinsic::getType(LLVMContext &Context,
+ ID id, ArrayRef<Type*> Tys) {
+ SmallVector<IITDescriptor, 8> Table;
+ getIntrinsicInfoTableEntries(id, Table);
+
+ ArrayRef<IITDescriptor> TableRef = Table;
+ Type *ResultTy = DecodeFixedType(TableRef, Tys, Context);
+
+ SmallVector<Type*, 8> ArgTys;
+ while (!TableRef.empty())
+ ArgTys.push_back(DecodeFixedType(TableRef, Tys, Context));
+
+ return FunctionType::get(ResultTy, ArgTys, false);
+}
+
+bool Intrinsic::isOverloaded(ID id) {
+#define GET_INTRINSIC_OVERLOAD_TABLE
+#include "llvm/Intrinsics.gen"
+#undef GET_INTRINSIC_OVERLOAD_TABLE
+}
+
+/// This defines the "Intrinsic::getAttributes(ID id)" method.
+#define GET_INTRINSIC_ATTRIBUTES
+#include "llvm/Intrinsics.gen"
+#undef GET_INTRINSIC_ATTRIBUTES
+
+Function *Intrinsic::getDeclaration(Module *M, ID id, ArrayRef<Type*> Tys) {
+ // There can never be multiple globals with the same name of different types,
+ // because intrinsics must be a specific type.
+ return
+ cast<Function>(M->getOrInsertFunction(getName(id, Tys),
+ getType(M->getContext(), id, Tys)));
+}
+
+// This defines the "Intrinsic::getIntrinsicForGCCBuiltin()" method.
+#define GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
+#include "llvm/Intrinsics.gen"
+#undef GET_LLVM_INTRINSIC_FOR_GCC_BUILTIN
+
+/// hasAddressTaken - returns true if there are any uses of this function
+/// other than direct calls or invokes to it.
+bool Function::hasAddressTaken(const User* *PutOffender) const {
+ for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
+ const User *U = *I;
+ if (isa<BlockAddress>(U))
+ continue;
+ if (!isa<CallInst>(U) && !isa<InvokeInst>(U))
+ return PutOffender ? (*PutOffender = U, true) : true;
+ ImmutableCallSite CS(cast<Instruction>(U));
+ if (!CS.isCallee(I))
+ return PutOffender ? (*PutOffender = U, true) : true;
+ }
+ return false;
+}
+
+bool Function::isDefTriviallyDead() const {
+ // Check the linkage
+ if (!hasLinkOnceLinkage() && !hasLocalLinkage() &&
+ !hasAvailableExternallyLinkage())
+ return false;
+
+ // Check if the function is used by anything other than a blockaddress.
+ for (Value::const_use_iterator I = use_begin(), E = use_end(); I != E; ++I)
+ if (!isa<BlockAddress>(*I))
+ return false;
+
+ return true;
+}
+
+/// callsFunctionThatReturnsTwice - Return true if the function has a call to
+/// setjmp or other function that gcc recognizes as "returning twice".
+bool Function::callsFunctionThatReturnsTwice() const {
+ for (const_inst_iterator
+ I = inst_begin(this), E = inst_end(this); I != E; ++I) {
+ const CallInst* callInst = dyn_cast<CallInst>(&*I);
+ if (!callInst)
+ continue;
+ if (callInst->canReturnTwice())
+ return true;
+ }
+
+ return false;
+}
+