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"
20 #include "llvm/Support/DebugLoc.h"
27 template<typename ValueSubClass, typename ItemParentClass>
28 class SymbolTableListTraits;
30 class Instruction : public User, public ilist_node<Instruction> {
31 void operator=(const Instruction &); // Do not implement
32 Instruction(const Instruction &); // Do not implement
35 DebugLoc DbgLoc; // 'dbg' Metadata cache.
38 /// HasMetadataBit - This is a bit stored in the SubClassData field which
39 /// indicates whether this instruction has metadata attached to it or not.
40 HasMetadataBit = 1 << 15
43 // Out of line virtual method, so the vtable, etc has a home.
46 /// use_back - Specialize the methods defined in Value, as we know that an
47 /// instruction can only be used by other instructions.
48 Instruction *use_back() { return cast<Instruction>(*use_begin());}
49 const Instruction *use_back() const { return cast<Instruction>(*use_begin());}
51 inline const BasicBlock *getParent() const { return Parent; }
52 inline BasicBlock *getParent() { return Parent; }
54 /// removeFromParent - This method unlinks 'this' from the containing basic
55 /// block, but does not delete it.
57 void removeFromParent();
59 /// eraseFromParent - This method unlinks 'this' from the containing basic
60 /// block and deletes it.
62 void eraseFromParent();
64 /// insertBefore - Insert an unlinked instructions into a basic block
65 /// immediately before the specified instruction.
66 void insertBefore(Instruction *InsertPos);
68 /// insertAfter - Insert an unlinked instructions into a basic block
69 /// immediately after the specified instruction.
70 void insertAfter(Instruction *InsertPos);
72 /// moveBefore - Unlink this instruction from its current basic block and
73 /// insert it into the basic block that MovePos lives in, right before
75 void moveBefore(Instruction *MovePos);
77 //===--------------------------------------------------------------------===//
78 // Subclass classification.
79 //===--------------------------------------------------------------------===//
81 /// getOpcode() returns a member of one of the enums like Instruction::Add.
82 unsigned getOpcode() const { return getValueID() - InstructionVal; }
84 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
85 bool isTerminator() const { return isTerminator(getOpcode()); }
86 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
87 bool isShift() { return isShift(getOpcode()); }
88 bool isCast() const { return isCast(getOpcode()); }
90 static const char* getOpcodeName(unsigned OpCode);
92 static inline bool isTerminator(unsigned OpCode) {
93 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
96 static inline bool isBinaryOp(unsigned Opcode) {
97 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
100 /// @brief Determine if the Opcode is one of the shift instructions.
101 static inline bool isShift(unsigned Opcode) {
102 return Opcode >= Shl && Opcode <= AShr;
105 /// isLogicalShift - Return true if this is a logical shift left or a logical
107 inline bool isLogicalShift() const {
108 return getOpcode() == Shl || getOpcode() == LShr;
111 /// isArithmeticShift - Return true if this is an arithmetic shift right.
112 inline bool isArithmeticShift() const {
113 return getOpcode() == AShr;
116 /// @brief Determine if the OpCode is one of the CastInst instructions.
117 static inline bool isCast(unsigned OpCode) {
118 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
121 //===--------------------------------------------------------------------===//
122 // Metadata manipulation.
123 //===--------------------------------------------------------------------===//
125 /// hasMetadata() - Return true if this instruction has any metadata attached
127 bool hasMetadata() const {
128 return !DbgLoc.isUnknown() || hasMetadataHashEntry();
131 /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
132 /// metadata attached to it other than a debug location.
133 bool hasMetadataOtherThanDebugLoc() const {
134 return hasMetadataHashEntry();
137 /// getMetadata - Get the metadata of given kind attached to this Instruction.
138 /// If the metadata is not found then return null.
139 MDNode *getMetadata(unsigned KindID) const {
140 if (!hasMetadata()) return 0;
141 return getMetadataImpl(KindID);
144 /// getMetadata - Get the metadata of given kind attached to this Instruction.
145 /// If the metadata is not found then return null.
146 MDNode *getMetadata(const char *Kind) const {
147 if (!hasMetadata()) return 0;
148 return getMetadataImpl(Kind);
151 /// getAllMetadata - Get all metadata attached to this Instruction. The first
152 /// element of each pair returned is the KindID, the second element is the
153 /// metadata value. This list is returned sorted by the KindID.
154 void getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode*> > &MDs)const{
156 getAllMetadataImpl(MDs);
159 /// getAllMetadataOtherThanDebugLoc - This does the same thing as
160 /// getAllMetadata, except that it filters out the debug location.
161 void getAllMetadataOtherThanDebugLoc(SmallVectorImpl<std::pair<unsigned,
162 MDNode*> > &MDs) const {
163 if (hasMetadataOtherThanDebugLoc())
164 getAllMetadataOtherThanDebugLocImpl(MDs);
167 /// setMetadata - Set the metadata of the specified kind to the specified
168 /// node. This updates/replaces metadata if already present, or removes it if
170 void setMetadata(unsigned KindID, MDNode *Node);
171 void setMetadata(const char *Kind, MDNode *Node);
173 /// setDebugLoc - Set the debug location information for this instruction.
174 void setDebugLoc(const DebugLoc &Loc) { DbgLoc = Loc; }
176 /// getDebugLoc - Return the debug location for this node as a DebugLoc.
177 const DebugLoc &getDebugLoc() const { return DbgLoc; }
180 /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
182 bool hasMetadataHashEntry() const {
183 return (getSubclassDataFromValue() & HasMetadataBit) != 0;
186 // These are all implemented in Metadata.cpp.
187 MDNode *getMetadataImpl(unsigned KindID) const;
188 MDNode *getMetadataImpl(const char *Kind) const;
189 void getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode*> > &)const;
190 void getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,
192 void clearMetadataHashEntries();
194 //===--------------------------------------------------------------------===//
195 // Predicates and helper methods.
196 //===--------------------------------------------------------------------===//
199 /// isAssociative - Return true if the instruction is associative:
201 /// Associative operators satisfy: x op (y op z) === (x op y) op z
203 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
205 bool isAssociative() const { return isAssociative(getOpcode()); }
206 static bool isAssociative(unsigned op);
208 /// isCommutative - Return true if the instruction is commutative:
210 /// Commutative operators satisfy: (x op y) === (y op x)
212 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
213 /// applied to any type.
215 bool isCommutative() const { return isCommutative(getOpcode()); }
216 static bool isCommutative(unsigned op);
218 /// mayWriteToMemory - Return true if this instruction may modify memory.
220 bool mayWriteToMemory() const;
222 /// mayReadFromMemory - Return true if this instruction may read memory.
224 bool mayReadFromMemory() const;
226 /// mayThrow - Return true if this instruction may throw an exception.
228 bool mayThrow() const;
230 /// mayHaveSideEffects - Return true if the instruction may have side effects.
232 /// Note that this does not consider malloc and alloca to have side
233 /// effects because the newly allocated memory is completely invisible to
234 /// instructions which don't used the returned value. For cases where this
235 /// matters, isSafeToSpeculativelyExecute may be more appropriate.
236 bool mayHaveSideEffects() const {
237 return mayWriteToMemory() || mayThrow();
240 /// isSafeToSpeculativelyExecute - Return true if the instruction does not
241 /// have any effects besides calculating the result and does not have
242 /// undefined behavior.
244 /// This method never returns true for an instruction that returns true for
245 /// mayHaveSideEffects; however, this method also does some other checks in
246 /// addition. It checks for undefined behavior, like dividing by zero or
247 /// loading from an invalid pointer (but not for undefined results, like a
248 /// shift with a shift amount larger than the width of the result). It checks
249 /// for malloc and alloca because speculatively executing them might cause a
250 /// memory leak. It also returns false for instructions related to control
251 /// flow, specifically terminators and PHI nodes.
253 /// This method only looks at the instruction itself and its operands, so if
254 /// this method returns true, it is safe to move the instruction as long as
255 /// the correct dominance relationships for the operands and users hold.
256 /// However, this method can return true for instructions that read memory;
257 /// for such instructions, moving them may change the resulting value.
258 bool isSafeToSpeculativelyExecute() const;
260 /// clone() - Create a copy of 'this' instruction that is identical in all
261 /// ways except the following:
262 /// * The instruction has no parent
263 /// * The instruction has no name
265 Instruction *clone() const;
267 /// isIdenticalTo - Return true if the specified instruction is exactly
268 /// identical to the current one. This means that all operands match and any
269 /// extra information (e.g. load is volatile) agree.
270 bool isIdenticalTo(const Instruction *I) const;
272 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
273 /// ignores the SubclassOptionalData flags, which specify conditions
274 /// under which the instruction's result is undefined.
275 bool isIdenticalToWhenDefined(const Instruction *I) const;
277 /// This function determines if the specified instruction executes the same
278 /// operation as the current one. This means that the opcodes, type, operand
279 /// types and any other factors affecting the operation must be the same. This
280 /// is similar to isIdenticalTo except the operands themselves don't have to
282 /// @returns true if the specified instruction is the same operation as
284 /// @brief Determine if one instruction is the same operation as another.
285 bool isSameOperationAs(const Instruction *I) const;
287 /// isUsedOutsideOfBlock - Return true if there are any uses of this
288 /// instruction in blocks other than the specified block. Note that PHI nodes
289 /// are considered to evaluate their operands in the corresponding predecessor
291 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
294 /// Methods for support type inquiry through isa, cast, and dyn_cast:
295 static inline bool classof(const Instruction *) { return true; }
296 static inline bool classof(const Value *V) {
297 return V->getValueID() >= Value::InstructionVal;
300 //----------------------------------------------------------------------
301 // Exported enumerations.
303 enum TermOps { // These terminate basic blocks
304 #define FIRST_TERM_INST(N) TermOpsBegin = N,
305 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
306 #define LAST_TERM_INST(N) TermOpsEnd = N+1
307 #include "llvm/Instruction.def"
311 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
312 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
313 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
314 #include "llvm/Instruction.def"
318 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
319 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
320 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
321 #include "llvm/Instruction.def"
325 #define FIRST_CAST_INST(N) CastOpsBegin = N,
326 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
327 #define LAST_CAST_INST(N) CastOpsEnd = N+1
328 #include "llvm/Instruction.def"
332 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
333 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
334 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
335 #include "llvm/Instruction.def"
338 // Shadow Value::setValueSubclassData with a private forwarding method so that
339 // subclasses cannot accidentally use it.
340 void setValueSubclassData(unsigned short D) {
341 Value::setValueSubclassData(D);
343 unsigned short getSubclassDataFromValue() const {
344 return Value::getSubclassDataFromValue();
347 void setHasMetadataHashEntry(bool V) {
348 setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
349 (V ? HasMetadataBit : 0));
352 friend class SymbolTableListTraits<Instruction, BasicBlock>;
353 void setParent(BasicBlock *P);
355 // Instruction subclasses can stick up to 15 bits of stuff into the
356 // SubclassData field of instruction with these members.
358 // Verify that only the low 15 bits are used.
359 void setInstructionSubclassData(unsigned short D) {
360 assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
361 setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
364 unsigned getSubclassDataFromInstruction() const {
365 return getSubclassDataFromValue() & ~HasMetadataBit;
368 Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
369 Instruction *InsertBefore = 0);
370 Instruction(const Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
371 BasicBlock *InsertAtEnd);
372 virtual Instruction *clone_impl() const = 0;
376 // Instruction* is only 4-byte aligned.
378 class PointerLikeTypeTraits<Instruction*> {
379 typedef Instruction* PT;
381 static inline void *getAsVoidPointer(PT P) { return P; }
382 static inline PT getFromVoidPointer(void *P) {
383 return static_cast<PT>(P);
385 enum { NumLowBitsAvailable = 2 };
388 } // End llvm namespace