-//===-- llvm/Value.h - Definition of the Value class -------------*- C++ -*--=//
+//===-- llvm/Value.h - Definition of the Value class ------------*- C++ -*-===//
//
-// This file defines the very important Value class. This is subclassed by a
-// bunch of other important classes, like Def, Method, Module, Type, etc...
+// 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_VALUE_H
#define LLVM_VALUE_H
+#include "llvm/AbstractTypeUser.h"
+#include "llvm/Use.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/Casting.h"
#include <string>
-#include <list>
-class User;
-class Type;
-template<class ValueSubclass, class ItemParentType> class ValueHolder;
+namespace llvm {
+
+class Constant;
+class Argument;
+class Instruction;
+class BasicBlock;
+class GlobalValue;
+class Function;
+class GlobalVariable;
+class GlobalAlias;
+class InlineAsm;
+class ValueSymbolTable;
+class TypeSymbolTable;
+template<typename ValueTy> class StringMapEntry;
+template <typename ValueTy = Value>
+class AssertingVH;
+typedef StringMapEntry<Value*> ValueName;
+class raw_ostream;
+class AssemblyAnnotationWriter;
+class ValueHandleBase;
+class LLVMContext;
+class Twine;
+class MDNode;
//===----------------------------------------------------------------------===//
// 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. All types can have
+/// a name and they should 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 {
-public:
- enum ValueTy {
- TypeVal, // This is an instance of Type
- ConstantVal, // This is an instance of ConstPoolVal
- MethodArgumentVal, // This is an instance of MethodArgument
- InstructionVal, // This is an instance of Instruction
-
- BasicBlockVal, // This is an instance of BasicBlock
- MethodVal, // This is an instance of Method
- ModuleVal, // This is an instance of Module
- };
+ 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:
- list<User *> Uses;
- string Name;
- const Type *Ty;
- ValueTy VTy;
+ /// 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;
+
+ PATypeHolder VTy;
+ Use *UseList;
+ friend class ValueSymbolTable; // Allow ValueSymbolTable to directly mod Name.
+ friend class ValueHandleBase;
+ friend class AbstractTypeUser;
+ ValueName *Name;
+
+ void operator=(const Value &); // Do not implement
Value(const Value &); // Do not implement
+
protected:
- inline void setType(const Type *ty) { Ty = ty; }
+ /// printCustom - Value subclasses can override this to implement custom
+ /// printing behavior.
+ virtual void printCustom(raw_ostream &O) const;
+
+ Value(const Type *Ty, unsigned scid);
public:
- Value(const Type *Ty, ValueTy vty, const string &name = "");
virtual ~Value();
- inline const Type *getType() const { return Ty; }
- inline ValueTy getValueType() const { return VTy; }
+ /// dump - Support for debugging, callable in GDB: V->dump()
+ //
+ void dump() const;
- inline bool hasName() const { return Name != ""; }
- inline const string &getName() const { return Name; }
- virtual void setName(const string &name) { Name = name; }
+ /// print - Implement operator<< on Value.
+ ///
+ void print(raw_ostream &O, AssemblyAnnotationWriter *AAW = 0) const;
+ /// All values are typed, get the type of this value.
+ ///
+ inline const Type *getType() const { return VTy; }
- // replaceAllUsesWith - Go through the uses list for this definition and make
- // each use point to "D" instead of "this". After this completes, 'this's
- // use list should be empty.
- //
- void replaceAllUsesWith(Value *D);
+ /// All values hold a context through their type.
+ LLVMContext &getContext() const;
+
+ // All values can potentially be named...
+ inline bool hasName() const { return Name != 0; }
+ ValueName *getValueName() const { return Name; }
+
+ /// 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.
+ ///
+ /// This is currently guaranteed to return a StringRef for which data() points
+ /// to a valid null terminated string. The use of StringRef.data() is
+ /// deprecated here, however, and clients should not rely on it. If such
+ /// behavior is needed, clients should use expensive getNameStr(), or switch
+ /// to an interface that does not depend on null termination.
+ StringRef getName() const;
+
+ /// getNameStr() - Return the name of the specified value, *constructing a
+ /// string* to hold it. This is guaranteed to construct a string and is very
+ /// expensive, clients should use getName() unless necessary.
+ std::string getNameStr() const;
+
+ /// setName() - Change the name of the value, choosing a new unique name if
+ /// the provided name is taken.
+ ///
+ /// \arg 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);
+
+ // uncheckedReplaceAllUsesWith - Just like replaceAllUsesWith but dangerous.
+ // Only use when in type resolution situations!
+ void uncheckedReplaceAllUsesWith(Value *V);
//----------------------------------------------------------------------
- // Methods for handling the list of uses of this DEF.
+ // Methods for handling the chain of uses of this Value.
//
- typedef list<User*>::iterator use_iterator;
- typedef list<User*>::const_iterator use_const_iterator;
+ 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 hasMoreThanNUses
+ /// to check for specific values.
+ unsigned getNumUses() const;
- inline unsigned use_size() const { return Uses.size(); }
- inline bool use_empty() const { return Uses.empty(); }
- inline use_iterator use_begin() { return Uses.begin(); }
- inline use_const_iterator use_begin() const { return Uses.begin(); }
- inline use_iterator use_end() { return Uses.end(); }
- inline use_const_iterator use_end() const { return Uses.end(); }
+ /// addUse - This method should only be used by the Use class.
+ ///
+ void addUse(Use &U) { U.addToList(&UseList); }
- inline void use_push_back(User *I) { Uses.push_back(I); }
- User *use_remove(use_iterator &I);
+ /// 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
+ 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;
+ }
+
+ /// 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;
+ }
- inline void addUse(User *I) { Uses.push_back(I); }
- void killUse(User *I);
+ /// 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; }
+
+ // Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const Value *) {
+ return true; // Values are always values.
+ }
+
+ /// getRawType - This should only be used to implement the vmcore library.
+ ///
+ const Type *getRawType() const { return VTy.getRawType(); }
+
+ /// stripPointerCasts - This method strips off any unneeded pointer
+ /// casts from the specified value, returning the original uncasted value.
+ /// Note that the returned value has pointer type if the specified value does.
+ Value *stripPointerCasts();
+ const Value *stripPointerCasts() const {
+ return const_cast<Value*>(this)->stripPointerCasts();
+ }
+
+ /// getUnderlyingObject - This method strips off any GEP address adjustments
+ /// and pointer casts from the specified value, returning the original object
+ /// being addressed. Note that the returned value has pointer type if the
+ /// specified value does. If the MaxLookup value is non-zero, it limits the
+ /// number of instructions to be stripped off.
+ Value *getUnderlyingObject(unsigned MaxLookup = 6);
+ const Value *getUnderlyingObject(unsigned MaxLookup = 6) const {
+ return const_cast<Value*>(this)->getUnderlyingObject(MaxLookup);
+ }
+
+ /// 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;
+
+protected:
+ unsigned short getSubclassDataFromValue() const { return SubclassData; }
+ void setValueSubclassData(unsigned short D) { SubclassData = D; }
};
-// UseTy and it's friendly typedefs (Use) are here to make keeping the "use"
-// list of a definition node up-to-date really easy.
+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<class ValueSubclass>
-class UseTy {
- ValueSubclass *Val;
- User *U;
-public:
- inline UseTy<ValueSubclass>(ValueSubclass *v, User *user) {
- Val = v; U = user;
- if (Val) Val->addUse(U);
+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;
}
+};
- inline ~UseTy<ValueSubclass>() { if (Val) Val->killUse(U); }
+template <> struct isa_impl<Instruction, Value> {
+ static inline bool doit(const Value &Val) {
+ return Val.getValueID() >= Value::InstructionVal;
+ }
+};
- inline operator ValueSubclass *() const { return Val; }
+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;
+ }
+};
- inline UseTy<ValueSubclass>(const UseTy<ValueSubclass> &user) {
- Val = 0;
- U = user.U;
- operator=(user.Val);
+template <> struct isa_impl<GlobalVariable, Value> {
+ static inline bool doit(const Value &Val) {
+ return Val.getValueID() == Value::GlobalVariableVal;
}
- inline ValueSubclass *operator=(ValueSubclass *V) {
- if (Val) Val->killUse(U);
- Val = V;
- if (V) V->addUse(U);
- return V;
+};
+
+template <> struct isa_impl<GlobalAlias, Value> {
+ static inline bool doit(const Value &Val) {
+ return Val.getValueID() == Value::GlobalAliasVal;
}
+};
- inline ValueSubclass *operator->() { return Val; }
- inline const ValueSubclass *operator->() const { return Val; }
+template <> struct isa_impl<GlobalValue, Value> {
+ static inline bool doit(const Value &Val) {
+ return isa<GlobalVariable>(Val) || isa<Function>(Val) ||
+ isa<GlobalAlias>(Val);
+ }
+};
- inline UseTy<ValueSubclass> &operator=(const UseTy<ValueSubclass> &user) {
- if (Val) Val->killUse(U);
- Val = user.Val;
- Val->addUse(U);
- return *this;
+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 };
};
-typedef UseTy<Value> Use;
+} // End llvm namespace
#endif
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