1 //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file contains the declaration of the Instruction class, which is the
11 // base class for all of the LLVM instructions.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_INSTRUCTION_H
16 #define LLVM_INSTRUCTION_H
18 #include "llvm/User.h"
19 #include "llvm/ADT/ilist_node.h"
23 template<typename ValueSubClass, typename ItemParentClass>
24 class SymbolTableListTraits;
26 class Instruction : public User, public ilist_node<Instruction> {
27 void operator=(const Instruction &); // Do not implement
28 Instruction(const Instruction &); // Do not implement
32 friend class SymbolTableListTraits<Instruction, BasicBlock>;
33 void setParent(BasicBlock *P);
35 Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
36 Instruction *InsertBefore = 0);
37 Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
38 BasicBlock *InsertAtEnd);
40 // Out of line virtual method, so the vtable, etc has a home.
43 /// mayWriteToMemory - Return true if this instruction may modify memory.
45 bool mayWriteToMemory() const;
47 /// mayReadFromMemory - Return true if this instruction may read memory.
49 bool mayReadFromMemory() const;
51 /// clone() - Create a copy of 'this' instruction that is identical in all
52 /// ways except the following:
53 /// * The instruction has no parent
54 /// * The instruction has no name
56 virtual Instruction *clone() const = 0;
58 /// isIdenticalTo - Return true if the specified instruction is exactly
59 /// identical to the current one. This means that all operands match and any
60 /// extra information (e.g. load is volatile) agree.
61 bool isIdenticalTo(const Instruction *I) const;
63 /// This function determines if the specified instruction executes the same
64 /// operation as the current one. This means that the opcodes, type, operand
65 /// types and any other factors affecting the operation must be the same. This
66 /// is similar to isIdenticalTo except the operands themselves don't have to
68 /// @returns true if the specified instruction is the same operation as
70 /// @brief Determine if one instruction is the same operation as another.
71 bool isSameOperationAs(const Instruction *I) const;
73 /// isUsedOutsideOfBlock - Return true if there are any uses of this
74 /// instruction in blocks other than the specified block. Note that PHI nodes
75 /// are considered to evaluate their operands in the corresponding predecessor
77 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
80 /// use_back - Specialize the methods defined in Value, as we know that an
81 /// instruction can only be used by other instructions.
82 Instruction *use_back() { return cast<Instruction>(*use_begin());}
83 const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
85 // Accessor methods...
87 inline const BasicBlock *getParent() const { return Parent; }
88 inline BasicBlock *getParent() { return Parent; }
90 /// removeFromParent - This method unlinks 'this' from the containing basic
91 /// block, but does not delete it.
93 void removeFromParent();
95 /// eraseFromParent - This method unlinks 'this' from the containing basic
96 /// block and deletes it.
98 void eraseFromParent();
100 /// insertBefore - Insert an unlinked instructions into a basic block
101 /// immediately before the specified instruction.
102 void insertBefore(Instruction *InsertPos);
104 /// insertAfter - Insert an unlinked instructions into a basic block
105 /// immediately after the specified instruction.
106 void insertAfter(Instruction *InsertPos);
108 /// moveBefore - Unlink this instruction from its current basic block and
109 /// insert it into the basic block that MovePos lives in, right before
111 void moveBefore(Instruction *MovePos);
113 // ---------------------------------------------------------------------------
114 /// Subclass classification... getOpcode() returns a member of
115 /// one of the enums that is coming soon (down below)...
117 unsigned getOpcode() const { return getValueID() - InstructionVal; }
118 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
119 bool isTerminator() const { return isTerminator(getOpcode()); }
120 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
121 bool isShift() { return isShift(getOpcode()); }
122 bool isCast() const { return isCast(getOpcode()); }
126 static const char* getOpcodeName(unsigned OpCode);
128 static inline bool isTerminator(unsigned OpCode) {
129 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
132 static inline bool isBinaryOp(unsigned Opcode) {
133 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
136 /// @brief Determine if the Opcode is one of the shift instructions.
137 static inline bool isShift(unsigned Opcode) {
138 return Opcode >= Shl && Opcode <= AShr;
141 /// isLogicalShift - Return true if this is a logical shift left or a logical
143 inline bool isLogicalShift() const {
144 return getOpcode() == Shl || getOpcode() == LShr;
147 /// isArithmeticShift - Return true if this is an arithmetic shift right.
148 inline bool isArithmeticShift() const {
149 return getOpcode() == AShr;
152 /// @brief Determine if the OpCode is one of the CastInst instructions.
153 static inline bool isCast(unsigned OpCode) {
154 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
157 /// isAssociative - Return true if the instruction is associative:
159 /// Associative operators satisfy: x op (y op z) === (x op y) op z
161 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative, when
162 /// not applied to floating point types.
164 bool isAssociative() const { return isAssociative(getOpcode(), getType()); }
165 static bool isAssociative(unsigned op, const Type *Ty);
167 /// isCommutative - Return true if the instruction is commutative:
169 /// Commutative operators satisfy: (x op y) === (y op x)
171 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
172 /// applied to any type.
174 bool isCommutative() const { return isCommutative(getOpcode()); }
175 static bool isCommutative(unsigned op);
177 /// isTrapping - Return true if the instruction may trap.
179 bool isTrapping() const {
180 return isTrapping(getOpcode());
182 static bool isTrapping(unsigned op);
184 /// Methods for support type inquiry through isa, cast, and dyn_cast:
185 static inline bool classof(const Instruction *) { return true; }
186 static inline bool classof(const Value *V) {
187 return V->getValueID() >= Value::InstructionVal;
190 //----------------------------------------------------------------------
191 // Exported enumerations...
193 enum TermOps { // These terminate basic blocks
194 #define FIRST_TERM_INST(N) TermOpsBegin = N,
195 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
196 #define LAST_TERM_INST(N) TermOpsEnd = N+1
197 #include "llvm/Instruction.def"
201 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
202 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
203 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
204 #include "llvm/Instruction.def"
208 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
209 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
210 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
211 #include "llvm/Instruction.def"
215 #define FIRST_CAST_INST(N) CastOpsBegin = N,
216 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
217 #define LAST_CAST_INST(N) CastOpsEnd = N+1
218 #include "llvm/Instruction.def"
222 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
223 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
224 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
225 #include "llvm/Instruction.def"
229 // Instruction* is only 4-byte aligned.
231 class PointerLikeTypeTraits<Instruction*> {
232 typedef Instruction* PT;
234 static inline void *getAsVoidPointer(PT P) { return P; }
235 static inline PT getFromVoidPointer(void *P) {
236 return static_cast<PT>(P);
238 enum { NumLowBitsAvailable = 2 };
241 } // End llvm namespace