}
};
+//===----------------------------------------------------------------------===//
+// CastInst Class
+//===----------------------------------------------------------------------===//
+
+/// CastInst - This is the base class for all instructions that perform data
+/// casts. It is simply provided so that instruction category testing
+/// can be performed with code like:
+///
+/// if (isa<CastInst>(Instr)) { ... }
+/// @brief Base class of casting instructions.
+class CastInst : public UnaryInstruction {
+ /// @brief Copy constructor
+ CastInst(const CastInst &CI)
+ : UnaryInstruction(CI.getType(), CI.getOpcode(), CI.getOperand(0)) {
+ }
+ /// @brief Do not allow default construction
+ CastInst();
+protected:
+ /// @brief Constructor with insert-before-instruction semantics for subclasses
+ CastInst(const Type *Ty, unsigned iType, Value *S,
+ const std::string &Name = "", Instruction *InsertBefore = 0)
+ : UnaryInstruction(Ty, iType, S, Name, InsertBefore) {
+ }
+ /// @brief Constructor with insert-at-end-of-block semantics for subclasses
+ CastInst(const Type *Ty, unsigned iType, Value *S,
+ const std::string &Name, BasicBlock *InsertAtEnd)
+ : UnaryInstruction(Ty, iType, S, Name, InsertAtEnd) {
+ }
+public:
+ /// Provides a way to construct any of the CastInst subclasses using an
+ /// opcode instead of the subclass's constructor. The opcode must be in the
+ /// CastOps category (Instruction::isCast(opcode) returns true). This
+ /// constructor has insert-before-instruction semantics to automatically
+ /// insert the new CastInst before InsertBefore (if it is non-null).
+ /// @brief Construct any of the CastInst subclasses
+ static CastInst *create(
+ Instruction::CastOps, ///< The opcode of the cast instruction
+ Value *S, ///< The value to be casted (operand 0)
+ const Type *Ty, ///< The type to which cast should be made
+ const std::string &Name = "", ///< Name for the instruction
+ Instruction *InsertBefore = 0 ///< Place to insert the instruction
+ );
+ /// Provides a way to construct any of the CastInst subclasses using an
+ /// opcode instead of the subclass's constructor. The opcode must be in the
+ /// CastOps category. This constructor has insert-at-end-of-block semantics
+ /// to automatically insert the new CastInst at the end of InsertAtEnd (if
+ /// its non-null).
+ /// @brief Construct any of the CastInst subclasses
+ static CastInst *create(
+ Instruction::CastOps, ///< The opcode for the cast instruction
+ Value *S, ///< The value to be casted (operand 0)
+ const Type *Ty, ///< The type to which operand is casted
+ const std::string &Name, ///< The name for the instruction
+ BasicBlock *InsertAtEnd ///< The block to insert the instruction into
+ );
+
+ /// Returns the opcode necessary to cast Val into Ty using usual casting
+ /// rules.
+ static Instruction::CastOps getCastOpcode(
+ const Value *Val, ///< The value to cast
+ const Type *Ty ///< The Type to which the value should be casted
+ );
+
+ /// Joins the create method (with insert-before-instruction semantics) above
+ /// with the getCastOpcode method. getOpcode(S,Ty) is called first to
+ /// obtain the opcode for casting S to type Ty. Then the get(...) method is
+ /// called to create the CastInst and insert it. The instruction is
+ /// inserted before InsertBefore (if it is non-null). The cast created is
+ /// inferred, because only the types involved are used in determining which
+ /// cast opcode to use. For specific casts, use one of the create methods.
+ /// @brief Inline helper method to join create with getCastOpcode.
+ inline static CastInst *createInferredCast(
+ Value *S, ///< The value to be casted (operand 0)
+ const Type *Ty, ///< Type to which operand should be casted
+ const std::string &Name = "", ///< Name for the instruction
+ Instruction *InsertBefore = 0 ///< Place to insert the CastInst
+ ) {
+ return create(getCastOpcode(S, Ty), S, Ty, Name, InsertBefore);
+ }
+
+ /// Joins the get method (with insert-at-end-of-block semantics) method
+ /// above with the getCastOpcode method. getOpcode(S,Ty) is called first to
+ /// obtain the usual casting opcode for casting S to type Ty. Then the
+ /// get(...) method is called to create the CastInst and insert it. The
+ /// instruction is inserted at the end of InsertAtEnd (if it is non-null).
+ /// The created cast is inferred, because only the types involved are used
+ /// in determining which cast opcode to use. For specific casts, use one of
+ /// the create methods.
+ /// @brief Inline helper method to join create with getCastOpcode.
+ inline static CastInst *createInferredCast(
+ Value *S, ///< The value to be casted (operand 0)
+ const Type *Ty, ///< Type to which operand should be casted
+ const std::string &Name, ///< Name for the instruction
+ BasicBlock *InsertAtEnd ///< The block to insert the instruction into
+ ) {
+ return create(getCastOpcode(S, Ty), S, Ty, Name, InsertAtEnd);
+ }
+
+ /// There are several places where we need to know if a cast instruction
+ /// only deals with integer source and destination types. To simplify that
+ /// logic, this method is provided.
+ /// @returns true iff the cast has only integral typed operand and dest type.
+ /// @brief Determine if this is an integer-only cast.
+ bool isIntegerCast() const;
+
+ /// A lossless cast is one that does not alter the basic value. It implies
+ /// a no-op cast but is more stringent, preventing things like int->float,
+ /// long->double, int->ptr, or packed->anything.
+ /// @returns true iff the cast is lossless.
+ /// @brief Determine if this is a lossless cast.
+ bool isLosslessCast() const;
+
+ /// A no-op cast is one that can be effected without changing any bits.
+ /// It implies that the source and destination types are the same size. The
+ /// IntPtrTy argument is used to make accurate determinations for casts
+ /// involving Integer and Pointer types. They are no-op casts if the integer
+ /// is the same size as the pointer. However, pointer size varies with
+ /// platform. Generally, the result of TargetData::getIntPtrType() should be
+ /// passed in. If that's not available, use Type::ULongTy, which will make
+ /// the isNoopCast call conservative.
+ /// @brief Determine if this cast is a no-op cast.
+ bool isNoopCast(
+ const Type *IntPtrTy ///< Integer type corresponding to pointer
+ ) const;
+
+ /// Determine how a pair of casts can be eliminated, if they can be at all.
+ /// This is a helper function for both CastInst and ConstantExpr.
+ /// @returns 0 if the CastInst pair can't be eliminated
+ /// @returns Instruction::CastOps value for a cast that can replace
+ /// the pair, casting SrcTy to DstTy.
+ /// @brief Determine if a cast pair is eliminable
+ static unsigned isEliminableCastPair(
+ Instruction::CastOps firstOpcode, ///< Opcode of first cast
+ Instruction::CastOps secondOpcode, ///< Opcode of second cast
+ const Type *SrcTy, ///< SrcTy of 1st cast
+ const Type *MidTy, ///< DstTy of 1st cast & SrcTy of 2nd cast
+ const Type *DstTy, ///< DstTy of 2nd cast
+ const Type *IntPtrTy ///< Integer type corresponding to Ptr types
+ );
+
+ /// @brief Return the opcode of this CastInst
+ Instruction::CastOps getOpcode() const {
+ return Instruction::CastOps(Instruction::getOpcode());
+ }
+
+ /// @brief Methods for support type inquiry through isa, cast, and dyn_cast:
+ static inline bool classof(const CastInst *) { return true; }
+ static inline bool classof(const Instruction *I) {
+ return I->getOpcode() >= CastOpsBegin && I->getOpcode() < CastOpsEnd;
+ }
+ static inline bool classof(const Value *V) {
+ return isa<Instruction>(V) && classof(cast<Instruction>(V));
+ }
+};
+
//===----------------------------------------------------------------------===//
// CmpInst Class
//===----------------------------------------------------------------------===//
projects / oota-llvm.git / blobdiff