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Diffstat (limited to 'contrib/llvm/include/llvm/IR/Value.h')
| -rw-r--r-- | contrib/llvm/include/llvm/IR/Value.h | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/contrib/llvm/include/llvm/IR/Value.h b/contrib/llvm/include/llvm/IR/Value.h new file mode 100644 index 0000000..a4f7862 --- /dev/null +++ b/contrib/llvm/include/llvm/IR/Value.h @@ -0,0 +1,411 @@ +//===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file declares the Value class. +// +//===----------------------------------------------------------------------===// + +#ifndef LLVM_IR_VALUE_H +#define LLVM_IR_VALUE_H + +#include "llvm/IR/Use.h" +#include "llvm/Support/Casting.h" +#include "llvm/Support/Compiler.h" + +namespace llvm { + +class Constant; +class Argument; +class Instruction; +class BasicBlock; +class GlobalValue; +class Function; +class GlobalVariable; +class GlobalAlias; +class InlineAsm; +class ValueSymbolTable; +template<typename ValueTy> class StringMapEntry; +typedef StringMapEntry<Value*> ValueName; +class raw_ostream; +class AssemblyAnnotationWriter; +class ValueHandleBase; +class LLVMContext; +class Twine; +class MDNode; +class Type; +class StringRef; + +//===----------------------------------------------------------------------===// +// Value Class +//===----------------------------------------------------------------------===// + +/// This is a very important LLVM class. It is the base class of all values +/// computed by a program that may be used as operands to other values. Value is +/// the super class of other important classes such as Instruction and Function. +/// All Values have a Type. Type is not a subclass of Value. Some values can +/// have a name and they belong to some Module. Setting the name on the Value +/// automatically updates the module's symbol table. +/// +/// Every value has a "use list" that keeps track of which other Values are +/// using this Value. A Value can also have an arbitrary number of ValueHandle +/// objects that watch it and listen to RAUW and Destroy events. See +/// llvm/Support/ValueHandle.h for details. +/// +/// @brief LLVM Value Representation +class Value { + const unsigned char SubclassID; // Subclass identifier (for isa/dyn_cast) + unsigned char HasValueHandle : 1; // Has a ValueHandle pointing to this? +protected: + /// SubclassOptionalData - This member is similar to SubclassData, however it + /// is for holding information which may be used to aid optimization, but + /// which may be cleared to zero without affecting conservative + /// interpretation. + unsigned char SubclassOptionalData : 7; + +private: + /// SubclassData - This member is defined by this class, but is not used for + /// anything. Subclasses can use it to hold whatever state they find useful. + /// This field is initialized to zero by the ctor. + unsigned short SubclassData; + + Type *VTy; + Use *UseList; + + friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name. + friend class ValueHandleBase; + ValueName *Name; + + void operator=(const Value &) LLVM_DELETED_FUNCTION; + Value(const Value &) LLVM_DELETED_FUNCTION; + +protected: + /// printCustom - Value subclasses can override this to implement custom + /// printing behavior. + virtual void printCustom(raw_ostream &O) const; + + Value(Type *Ty, unsigned scid); +public: + virtual ~Value(); + + /// dump - Support for debugging, callable in GDB: V->dump() + // + void dump() const; + + /// print - Implement operator<< on Value. + /// + void print(raw_ostream &O, AssemblyAnnotationWriter *AAW = 0) const; + + /// All values are typed, get the type of this value. + /// + Type *getType() const { return VTy; } + + /// All values hold a context through their type. + LLVMContext &getContext() const; + + // All values can potentially be named. + bool hasName() const { return Name != 0 && SubclassID != MDStringVal; } + ValueName *getValueName() const { return Name; } + void setValueName(ValueName *VN) { Name = VN; } + + /// getName() - Return a constant reference to the value's name. This is cheap + /// and guaranteed to return the same reference as long as the value is not + /// modified. + StringRef getName() const; + + /// setName() - Change the name of the value, choosing a new unique name if + /// the provided name is taken. + /// + /// \param Name The new name; or "" if the value's name should be removed. + void setName(const Twine &Name); + + + /// takeName - transfer the name from V to this value, setting V's name to + /// empty. It is an error to call V->takeName(V). + void takeName(Value *V); + + /// replaceAllUsesWith - Go through the uses list for this definition and make + /// each use point to "V" instead of "this". After this completes, 'this's + /// use list is guaranteed to be empty. + /// + void replaceAllUsesWith(Value *V); + + //---------------------------------------------------------------------- + // Methods for handling the chain of uses of this Value. + // + typedef value_use_iterator<User> use_iterator; + typedef value_use_iterator<const User> const_use_iterator; + + bool use_empty() const { return UseList == 0; } + use_iterator use_begin() { return use_iterator(UseList); } + const_use_iterator use_begin() const { return const_use_iterator(UseList); } + use_iterator use_end() { return use_iterator(0); } + const_use_iterator use_end() const { return const_use_iterator(0); } + User *use_back() { return *use_begin(); } + const User *use_back() const { return *use_begin(); } + + /// hasOneUse - Return true if there is exactly one user of this value. This + /// is specialized because it is a common request and does not require + /// traversing the whole use list. + /// + bool hasOneUse() const { + const_use_iterator I = use_begin(), E = use_end(); + if (I == E) return false; + return ++I == E; + } + + /// hasNUses - Return true if this Value has exactly N users. + /// + bool hasNUses(unsigned N) const; + + /// hasNUsesOrMore - Return true if this value has N users or more. This is + /// logically equivalent to getNumUses() >= N. + /// + bool hasNUsesOrMore(unsigned N) const; + + bool isUsedInBasicBlock(const BasicBlock *BB) const; + + /// getNumUses - This method computes the number of uses of this Value. This + /// is a linear time operation. Use hasOneUse, hasNUses, or hasNUsesOrMore + /// to check for specific values. + unsigned getNumUses() const; + + /// addUse - This method should only be used by the Use class. + /// + void addUse(Use &U) { U.addToList(&UseList); } + + /// An enumeration for keeping track of the concrete subclass of Value that + /// is actually instantiated. Values of this enumeration are kept in the + /// Value classes SubclassID field. They are used for concrete type + /// identification. + enum ValueTy { + ArgumentVal, // This is an instance of Argument + BasicBlockVal, // This is an instance of BasicBlock + FunctionVal, // This is an instance of Function + GlobalAliasVal, // This is an instance of GlobalAlias + GlobalVariableVal, // This is an instance of GlobalVariable + UndefValueVal, // This is an instance of UndefValue + BlockAddressVal, // This is an instance of BlockAddress + ConstantExprVal, // This is an instance of ConstantExpr + ConstantAggregateZeroVal, // This is an instance of ConstantAggregateZero + ConstantDataArrayVal, // This is an instance of ConstantDataArray + ConstantDataVectorVal, // This is an instance of ConstantDataVector + ConstantIntVal, // This is an instance of ConstantInt + ConstantFPVal, // This is an instance of ConstantFP + ConstantArrayVal, // This is an instance of ConstantArray + ConstantStructVal, // This is an instance of ConstantStruct + ConstantVectorVal, // This is an instance of ConstantVector + ConstantPointerNullVal, // This is an instance of ConstantPointerNull + MDNodeVal, // This is an instance of MDNode + MDStringVal, // This is an instance of MDString + InlineAsmVal, // This is an instance of InlineAsm + PseudoSourceValueVal, // This is an instance of PseudoSourceValue + FixedStackPseudoSourceValueVal, // This is an instance of + // FixedStackPseudoSourceValue + InstructionVal, // This is an instance of Instruction + // Enum values starting at InstructionVal are used for Instructions; + // don't add new values here! + + // Markers: + ConstantFirstVal = FunctionVal, + ConstantLastVal = ConstantPointerNullVal + }; + + /// getValueID - Return an ID for the concrete type of this object. This is + /// used to implement the classof checks. This should not be used for any + /// other purpose, as the values may change as LLVM evolves. Also, note that + /// for instructions, the Instruction's opcode is added to InstructionVal. So + /// this means three things: + /// # there is no value with code InstructionVal (no opcode==0). + /// # there are more possible values for the value type than in ValueTy enum. + /// # the InstructionVal enumerator must be the highest valued enumerator in + /// the ValueTy enum. + unsigned getValueID() const { + return SubclassID; + } + + /// getRawSubclassOptionalData - Return the raw optional flags value + /// contained in this value. This should only be used when testing two + /// Values for equivalence. + unsigned getRawSubclassOptionalData() const { + return SubclassOptionalData; + } + + /// clearSubclassOptionalData - Clear the optional flags contained in + /// this value. + void clearSubclassOptionalData() { + SubclassOptionalData = 0; + } + + /// hasSameSubclassOptionalData - Test whether the optional flags contained + /// in this value are equal to the optional flags in the given value. + bool hasSameSubclassOptionalData(const Value *V) const { + return SubclassOptionalData == V->SubclassOptionalData; + } + + /// intersectOptionalDataWith - Clear any optional flags in this value + /// that are not also set in the given value. + void intersectOptionalDataWith(const Value *V) { + SubclassOptionalData &= V->SubclassOptionalData; + } + + /// hasValueHandle - Return true if there is a value handle associated with + /// this value. + bool hasValueHandle() const { return HasValueHandle; } + + /// stripPointerCasts - This method strips off any unneeded pointer casts and + /// all-zero GEPs from the specified value, returning the original uncasted + /// value. If this is called on a non-pointer value, it returns 'this'. + Value *stripPointerCasts(); + const Value *stripPointerCasts() const { + return const_cast<Value*>(this)->stripPointerCasts(); + } + + /// stripInBoundsConstantOffsets - This method strips off unneeded pointer casts and + /// all-constant GEPs from the specified value, returning the original + /// pointer value. If this is called on a non-pointer value, it returns + /// 'this'. + Value *stripInBoundsConstantOffsets(); + const Value *stripInBoundsConstantOffsets() const { + return const_cast<Value*>(this)->stripInBoundsConstantOffsets(); + } + + /// stripInBoundsOffsets - This method strips off unneeded pointer casts and + /// any in-bounds Offsets from the specified value, returning the original + /// pointer value. If this is called on a non-pointer value, it returns + /// 'this'. + Value *stripInBoundsOffsets(); + const Value *stripInBoundsOffsets() const { + return const_cast<Value*>(this)->stripInBoundsOffsets(); + } + + /// isDereferenceablePointer - Test if this value is always a pointer to + /// allocated and suitably aligned memory for a simple load or store. + bool isDereferenceablePointer() const; + + /// DoPHITranslation - If this value is a PHI node with CurBB as its parent, + /// return the value in the PHI node corresponding to PredBB. If not, return + /// ourself. This is useful if you want to know the value something has in a + /// predecessor block. + Value *DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB); + + const Value *DoPHITranslation(const BasicBlock *CurBB, + const BasicBlock *PredBB) const{ + return const_cast<Value*>(this)->DoPHITranslation(CurBB, PredBB); + } + + /// MaximumAlignment - This is the greatest alignment value supported by + /// load, store, and alloca instructions, and global values. + static const unsigned MaximumAlignment = 1u << 29; + + /// mutateType - Mutate the type of this Value to be of the specified type. + /// Note that this is an extremely dangerous operation which can create + /// completely invalid IR very easily. It is strongly recommended that you + /// recreate IR objects with the right types instead of mutating them in + /// place. + void mutateType(Type *Ty) { + VTy = Ty; + } + +protected: + unsigned short getSubclassDataFromValue() const { return SubclassData; } + void setValueSubclassData(unsigned short D) { SubclassData = D; } +}; + +inline raw_ostream &operator<<(raw_ostream &OS, const Value &V) { + V.print(OS); + return OS; +} + +void Use::set(Value *V) { + if (Val) removeFromList(); + Val = V; + if (V) V->addUse(*this); +} + + +// isa - Provide some specializations of isa so that we don't have to include +// the subtype header files to test to see if the value is a subclass... +// +template <> struct isa_impl<Constant, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() >= Value::ConstantFirstVal && + Val.getValueID() <= Value::ConstantLastVal; + } +}; + +template <> struct isa_impl<Argument, Value> { + static inline bool doit (const Value &Val) { + return Val.getValueID() == Value::ArgumentVal; + } +}; + +template <> struct isa_impl<InlineAsm, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::InlineAsmVal; + } +}; + +template <> struct isa_impl<Instruction, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() >= Value::InstructionVal; + } +}; + +template <> struct isa_impl<BasicBlock, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::BasicBlockVal; + } +}; + +template <> struct isa_impl<Function, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::FunctionVal; + } +}; + +template <> struct isa_impl<GlobalVariable, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::GlobalVariableVal; + } +}; + +template <> struct isa_impl<GlobalAlias, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::GlobalAliasVal; + } +}; + +template <> struct isa_impl<GlobalValue, Value> { + static inline bool doit(const Value &Val) { + return isa<GlobalVariable>(Val) || isa<Function>(Val) || + isa<GlobalAlias>(Val); + } +}; + +template <> struct isa_impl<MDNode, Value> { + static inline bool doit(const Value &Val) { + return Val.getValueID() == Value::MDNodeVal; + } +}; + +// Value* is only 4-byte aligned. +template<> +class PointerLikeTypeTraits<Value*> { + typedef Value* PT; +public: + static inline void *getAsVoidPointer(PT P) { return P; } + static inline PT getFromVoidPointer(void *P) { + return static_cast<PT>(P); + } + enum { NumLowBitsAvailable = 2 }; +}; + +} // End llvm namespace + +#endif |
