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 /// clone() - Create a copy of 'this' instruction that is identical in all
44 /// ways except the following:
45 /// * The instruction has no parent
46 /// * The instruction has no name
48 virtual Instruction *clone() const = 0;
50 /// isIdenticalTo - Return true if the specified instruction is exactly
51 /// identical to the current one. This means that all operands match and any
52 /// extra information (e.g. load is volatile) agree.
53 bool isIdenticalTo(const Instruction *I) const;
55 /// This function determines if the specified instruction executes the same
56 /// operation as the current one. This means that the opcodes, type, operand
57 /// types and any other factors affecting the operation must be the same. This
58 /// is similar to isIdenticalTo except the operands themselves don't have to
60 /// @returns true if the specified instruction is the same operation as
62 /// @brief Determine if one instruction is the same operation as another.
63 bool isSameOperationAs(const Instruction *I) const;
65 /// isUsedOutsideOfBlock - Return true if there are any uses of this
66 /// instruction in blocks other than the specified block. Note that PHI nodes
67 /// are considered to evaluate their operands in the corresponding predecessor
69 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
72 /// use_back - Specialize the methods defined in Value, as we know that an
73 /// instruction can only be used by other instructions.
74 Instruction *use_back() { return cast<Instruction>(*use_begin());}
75 const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
77 // Accessor methods...
79 inline const BasicBlock *getParent() const { return Parent; }
80 inline BasicBlock *getParent() { return Parent; }
82 /// removeFromParent - This method unlinks 'this' from the containing basic
83 /// block, but does not delete it.
85 void removeFromParent();
87 /// eraseFromParent - This method unlinks 'this' from the containing basic
88 /// block and deletes it.
90 void eraseFromParent();
92 /// insertBefore - Insert an unlinked instructions into a basic block
93 /// immediately before the specified instruction.
94 void insertBefore(Instruction *InsertPos);
96 /// insertAfter - Insert an unlinked instructions into a basic block
97 /// immediately after the specified instruction.
98 void insertAfter(Instruction *InsertPos);
100 /// moveBefore - Unlink this instruction from its current basic block and
101 /// insert it into the basic block that MovePos lives in, right before
103 void moveBefore(Instruction *MovePos);
105 // ---------------------------------------------------------------------------
106 /// Subclass classification... getOpcode() returns a member of
107 /// one of the enums that is coming soon (down below)...
109 unsigned getOpcode() const { return getValueID() - InstructionVal; }
110 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
111 bool isTerminator() const { return isTerminator(getOpcode()); }
112 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
113 bool isShift() { return isShift(getOpcode()); }
114 bool isCast() const { return isCast(getOpcode()); }
118 static const char* getOpcodeName(unsigned OpCode);
120 static inline bool isTerminator(unsigned OpCode) {
121 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
124 static inline bool isBinaryOp(unsigned Opcode) {
125 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
128 /// @brief Determine if the Opcode is one of the shift instructions.
129 static inline bool isShift(unsigned Opcode) {
130 return Opcode >= Shl && Opcode <= AShr;
133 /// isLogicalShift - Return true if this is a logical shift left or a logical
135 inline bool isLogicalShift() const {
136 return getOpcode() == Shl || getOpcode() == LShr;
139 /// isArithmeticShift - Return true if this is an arithmetic shift right.
140 inline bool isArithmeticShift() const {
141 return getOpcode() == AShr;
144 /// @brief Determine if the OpCode is one of the CastInst instructions.
145 static inline bool isCast(unsigned OpCode) {
146 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
149 /// isAssociative - Return true if the instruction is associative:
151 /// Associative operators satisfy: x op (y op z) === (x op y) op z
153 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative, when
154 /// not applied to floating point types.
156 bool isAssociative() const { return isAssociative(getOpcode(), getType()); }
157 static bool isAssociative(unsigned op, const Type *Ty);
159 /// isCommutative - Return true if the instruction is commutative:
161 /// Commutative operators satisfy: (x op y) === (y op x)
163 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
164 /// applied to any type.
166 bool isCommutative() const { return isCommutative(getOpcode()); }
167 static bool isCommutative(unsigned op);
169 /// isTrapping - Return true if the instruction may trap.
171 bool isTrapping() const {
172 return isTrapping(getOpcode());
174 static bool isTrapping(unsigned op);
176 /// mayWriteToMemory - Return true if this instruction may modify memory.
178 bool mayWriteToMemory() const;
180 /// mayReadFromMemory - Return true if this instruction may read memory.
182 bool mayReadFromMemory() const;
184 /// mayThrow - Return true if this instruction may throw an exception.
186 bool mayThrow() const;
188 /// mayHaveSideEffects - Return true if the instruction may have side effects.
190 bool mayHaveSideEffects() const {
191 return mayWriteToMemory() || mayThrow();
194 /// Methods for support type inquiry through isa, cast, and dyn_cast:
195 static inline bool classof(const Instruction *) { return true; }
196 static inline bool classof(const Value *V) {
197 return V->getValueID() >= Value::InstructionVal;
200 //----------------------------------------------------------------------
201 // Exported enumerations...
203 enum TermOps { // These terminate basic blocks
204 #define FIRST_TERM_INST(N) TermOpsBegin = N,
205 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
206 #define LAST_TERM_INST(N) TermOpsEnd = N+1
207 #include "llvm/Instruction.def"
211 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
212 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
213 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
214 #include "llvm/Instruction.def"
218 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
219 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
220 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
221 #include "llvm/Instruction.def"
225 #define FIRST_CAST_INST(N) CastOpsBegin = N,
226 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
227 #define LAST_CAST_INST(N) CastOpsEnd = N+1
228 #include "llvm/Instruction.def"
232 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
233 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
234 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
235 #include "llvm/Instruction.def"
239 // Instruction* is only 4-byte aligned.
241 class PointerLikeTypeTraits<Instruction*> {
242 typedef Instruction* PT;
244 static inline void *getAsVoidPointer(PT P) { return P; }
245 static inline PT getFromVoidPointer(void *P) {
246 return static_cast<PT>(P);
248 enum { NumLowBitsAvailable = 2 };
251 } // End llvm namespace