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_IR_INSTRUCTION_H
16 #define LLVM_IR_INSTRUCTION_H
18 #include "llvm/ADT/ArrayRef.h"
19 #include "llvm/ADT/ilist_node.h"
20 #include "llvm/IR/DebugLoc.h"
21 #include "llvm/IR/SymbolTableListTraits.h"
22 #include "llvm/IR/User.h"
33 struct SymbolTableListSentinelTraits<Instruction>
34 : public ilist_half_embedded_sentinel_traits<Instruction> {};
36 class Instruction : public User,
37 public ilist_node_with_parent<Instruction, BasicBlock> {
38 void operator=(const Instruction &) = delete;
39 Instruction(const Instruction &) = delete;
42 DebugLoc DbgLoc; // 'dbg' Metadata cache.
45 /// HasMetadataBit - This is a bit stored in the SubClassData field which
46 /// indicates whether this instruction has metadata attached to it or not.
47 HasMetadataBit = 1 << 15
50 // Out of line virtual method, so the vtable, etc has a home.
51 ~Instruction() override;
53 /// user_back - Specialize the methods defined in Value, as we know that an
54 /// instruction can only be used by other instructions.
55 Instruction *user_back() { return cast<Instruction>(*user_begin());}
56 const Instruction *user_back() const { return cast<Instruction>(*user_begin());}
58 inline const BasicBlock *getParent() const { return Parent; }
59 inline BasicBlock *getParent() { return Parent; }
61 /// \brief Return the module owning the function this instruction belongs to
62 /// or nullptr it the function does not have a module.
64 /// Note: this is undefined behavior if the instruction does not have a
65 /// parent, or the parent basic block does not have a parent function.
66 const Module *getModule() const;
69 /// \brief Return the function this instruction belongs to.
71 /// Note: it is undefined behavior to call this on an instruction not
72 /// currently inserted into a function.
73 const Function *getFunction() const;
74 Function *getFunction();
76 /// removeFromParent - This method unlinks 'this' from the containing basic
77 /// block, but does not delete it.
79 void removeFromParent();
81 /// eraseFromParent - This method unlinks 'this' from the containing basic
82 /// block and deletes it.
84 /// \returns an iterator pointing to the element after the erased one
85 SymbolTableList<Instruction>::iterator eraseFromParent();
87 /// Insert an unlinked instruction into a basic block immediately before
88 /// the specified instruction.
89 void insertBefore(Instruction *InsertPos);
91 /// Insert an unlinked instruction into a basic block immediately after the
92 /// specified instruction.
93 void insertAfter(Instruction *InsertPos);
95 /// moveBefore - Unlink this instruction from its current basic block and
96 /// insert it into the basic block that MovePos lives in, right before
98 void moveBefore(Instruction *MovePos);
100 //===--------------------------------------------------------------------===//
101 // Subclass classification.
102 //===--------------------------------------------------------------------===//
104 /// getOpcode() returns a member of one of the enums like Instruction::Add.
105 unsigned getOpcode() const { return getValueID() - InstructionVal; }
107 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
108 bool isTerminator() const { return isTerminator(getOpcode()); }
109 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
110 bool isShift() { return isShift(getOpcode()); }
111 bool isCast() const { return isCast(getOpcode()); }
113 static const char* getOpcodeName(unsigned OpCode);
115 static inline bool isTerminator(unsigned OpCode) {
116 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
119 static inline bool isBinaryOp(unsigned Opcode) {
120 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
123 /// @brief Determine if the Opcode is one of the shift instructions.
124 static inline bool isShift(unsigned Opcode) {
125 return Opcode >= Shl && Opcode <= AShr;
128 /// isLogicalShift - Return true if this is a logical shift left or a logical
130 inline bool isLogicalShift() const {
131 return getOpcode() == Shl || getOpcode() == LShr;
134 /// isArithmeticShift - Return true if this is an arithmetic shift right.
135 inline bool isArithmeticShift() const {
136 return getOpcode() == AShr;
139 /// @brief Determine if the OpCode is one of the CastInst instructions.
140 static inline bool isCast(unsigned OpCode) {
141 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
144 //===--------------------------------------------------------------------===//
145 // Metadata manipulation.
146 //===--------------------------------------------------------------------===//
148 /// hasMetadata() - Return true if this instruction has any metadata attached
150 bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); }
152 /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
153 /// metadata attached to it other than a debug location.
154 bool hasMetadataOtherThanDebugLoc() const {
155 return hasMetadataHashEntry();
158 /// getMetadata - Get the metadata of given kind attached to this Instruction.
159 /// If the metadata is not found then return null.
160 MDNode *getMetadata(unsigned KindID) const {
161 if (!hasMetadata()) return nullptr;
162 return getMetadataImpl(KindID);
165 /// getMetadata - Get the metadata of given kind attached to this Instruction.
166 /// If the metadata is not found then return null.
167 MDNode *getMetadata(StringRef Kind) const {
168 if (!hasMetadata()) return nullptr;
169 return getMetadataImpl(Kind);
172 /// getAllMetadata - Get all metadata attached to this Instruction. The first
173 /// element of each pair returned is the KindID, the second element is the
174 /// metadata value. This list is returned sorted by the KindID.
176 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
178 getAllMetadataImpl(MDs);
181 /// getAllMetadataOtherThanDebugLoc - This does the same thing as
182 /// getAllMetadata, except that it filters out the debug location.
183 void getAllMetadataOtherThanDebugLoc(
184 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
185 if (hasMetadataOtherThanDebugLoc())
186 getAllMetadataOtherThanDebugLocImpl(MDs);
189 /// getAAMetadata - Fills the AAMDNodes structure with AA metadata from
190 /// this instruction. When Merge is true, the existing AA metadata is
191 /// merged with that from this instruction providing the most-general result.
192 void getAAMetadata(AAMDNodes &N, bool Merge = false) const;
194 /// setMetadata - Set the metadata of the specified kind to the specified
195 /// node. This updates/replaces metadata if already present, or removes it if
197 void setMetadata(unsigned KindID, MDNode *Node);
198 void setMetadata(StringRef Kind, MDNode *Node);
200 /// Drop all unknown metadata except for debug locations.
202 /// Passes are required to drop metadata they don't understand. This is a
203 /// convenience method for passes to do so.
204 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs);
205 void dropUnknownNonDebugMetadata() {
206 return dropUnknownNonDebugMetadata(None);
208 void dropUnknownNonDebugMetadata(unsigned ID1) {
209 return dropUnknownNonDebugMetadata(makeArrayRef(ID1));
211 void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) {
212 unsigned IDs[] = {ID1, ID2};
213 return dropUnknownNonDebugMetadata(IDs);
217 /// setAAMetadata - Sets the metadata on this instruction from the
218 /// AAMDNodes structure.
219 void setAAMetadata(const AAMDNodes &N);
221 /// setDebugLoc - Set the debug location information for this instruction.
222 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }
224 /// getDebugLoc - Return the debug location for this node as a DebugLoc.
225 const DebugLoc &getDebugLoc() const { return DbgLoc; }
227 /// Set or clear the unsafe-algebra flag on this instruction, which must be an
228 /// operator which supports this flag. See LangRef.html for the meaning of
230 void setHasUnsafeAlgebra(bool B);
232 /// Set or clear the no-nans flag on this instruction, which must be an
233 /// operator which supports this flag. See LangRef.html for the meaning of
235 void setHasNoNaNs(bool B);
237 /// Set or clear the no-infs flag on this instruction, which must be an
238 /// operator which supports this flag. See LangRef.html for the meaning of
240 void setHasNoInfs(bool B);
242 /// Set or clear the no-signed-zeros flag on this instruction, which must be
243 /// an operator which supports this flag. See LangRef.html for the meaning of
245 void setHasNoSignedZeros(bool B);
247 /// Set or clear the allow-reciprocal flag on this instruction, which must be
248 /// an operator which supports this flag. See LangRef.html for the meaning of
250 void setHasAllowReciprocal(bool B);
252 /// Convenience function for setting multiple fast-math flags on this
253 /// instruction, which must be an operator which supports these flags. See
254 /// LangRef.html for the meaning of these flags.
255 void setFastMathFlags(FastMathFlags FMF);
257 /// Convenience function for transferring all fast-math flag values to this
258 /// instruction, which must be an operator which supports these flags. See
259 /// LangRef.html for the meaning of these flags.
260 void copyFastMathFlags(FastMathFlags FMF);
262 /// Determine whether the unsafe-algebra flag is set.
263 bool hasUnsafeAlgebra() const;
265 /// Determine whether the no-NaNs flag is set.
266 bool hasNoNaNs() const;
268 /// Determine whether the no-infs flag is set.
269 bool hasNoInfs() const;
271 /// Determine whether the no-signed-zeros flag is set.
272 bool hasNoSignedZeros() const;
274 /// Determine whether the allow-reciprocal flag is set.
275 bool hasAllowReciprocal() const;
277 /// Convenience function for getting all the fast-math flags, which must be an
278 /// operator which supports these flags. See LangRef.html for the meaning of
280 FastMathFlags getFastMathFlags() const;
282 /// Copy I's fast-math flags
283 void copyFastMathFlags(const Instruction *I);
286 /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
288 bool hasMetadataHashEntry() const {
289 return (getSubclassDataFromValue() & HasMetadataBit) != 0;
292 // These are all implemented in Metadata.cpp.
293 MDNode *getMetadataImpl(unsigned KindID) const;
294 MDNode *getMetadataImpl(StringRef Kind) const;
296 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
297 void getAllMetadataOtherThanDebugLocImpl(
298 SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
299 void clearMetadataHashEntries();
301 //===--------------------------------------------------------------------===//
302 // Predicates and helper methods.
303 //===--------------------------------------------------------------------===//
306 /// isAssociative - Return true if the instruction is associative:
308 /// Associative operators satisfy: x op (y op z) === (x op y) op z
310 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
312 bool isAssociative() const;
313 static bool isAssociative(unsigned op);
315 /// isCommutative - Return true if the instruction is commutative:
317 /// Commutative operators satisfy: (x op y) === (y op x)
319 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
320 /// applied to any type.
322 bool isCommutative() const { return isCommutative(getOpcode()); }
323 static bool isCommutative(unsigned op);
325 /// isIdempotent - Return true if the instruction is idempotent:
327 /// Idempotent operators satisfy: x op x === x
329 /// In LLVM, the And and Or operators are idempotent.
331 bool isIdempotent() const { return isIdempotent(getOpcode()); }
332 static bool isIdempotent(unsigned op);
334 /// isNilpotent - Return true if the instruction is nilpotent:
336 /// Nilpotent operators satisfy: x op x === Id,
338 /// where Id is the identity for the operator, i.e. a constant such that
339 /// x op Id === x and Id op x === x for all x.
341 /// In LLVM, the Xor operator is nilpotent.
343 bool isNilpotent() const { return isNilpotent(getOpcode()); }
344 static bool isNilpotent(unsigned op);
346 /// mayWriteToMemory - Return true if this instruction may modify memory.
348 bool mayWriteToMemory() const;
350 /// mayReadFromMemory - Return true if this instruction may read memory.
352 bool mayReadFromMemory() const;
354 /// mayReadOrWriteMemory - Return true if this instruction may read or
357 bool mayReadOrWriteMemory() const {
358 return mayReadFromMemory() || mayWriteToMemory();
361 /// isAtomic - Return true if this instruction has an
362 /// AtomicOrdering of unordered or higher.
364 bool isAtomic() const;
366 /// mayThrow - Return true if this instruction may throw an exception.
368 bool mayThrow() const;
370 /// mayReturn - Return true if this is a function that may return.
371 /// this is true for all normal instructions. The only exception
372 /// is functions that are marked with the 'noreturn' attribute.
374 bool mayReturn() const;
376 /// mayHaveSideEffects - Return true if the instruction may have side effects.
378 /// Note that this does not consider malloc and alloca to have side
379 /// effects because the newly allocated memory is completely invisible to
380 /// instructions which don't use the returned value. For cases where this
381 /// matters, isSafeToSpeculativelyExecute may be more appropriate.
382 bool mayHaveSideEffects() const {
383 return mayWriteToMemory() || mayThrow() || !mayReturn();
386 /// \brief Return true if the instruction is a variety of EH-block.
387 bool isEHPad() const {
388 switch (getOpcode()) {
389 case Instruction::CatchPad:
390 case Instruction::CatchEndPad:
391 case Instruction::CleanupPad:
392 case Instruction::CleanupEndPad:
393 case Instruction::LandingPad:
394 case Instruction::TerminatePad:
401 /// clone() - Create a copy of 'this' instruction that is identical in all
402 /// ways except the following:
403 /// * The instruction has no parent
404 /// * The instruction has no name
406 Instruction *clone() const;
408 /// isIdenticalTo - Return true if the specified instruction is exactly
409 /// identical to the current one. This means that all operands match and any
410 /// extra information (e.g. load is volatile) agree.
411 bool isIdenticalTo(const Instruction *I) const;
413 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
414 /// ignores the SubclassOptionalData flags, which specify conditions
415 /// under which the instruction's result is undefined.
416 bool isIdenticalToWhenDefined(const Instruction *I) const;
418 /// When checking for operation equivalence (using isSameOperationAs) it is
419 /// sometimes useful to ignore certain attributes.
420 enum OperationEquivalenceFlags {
421 /// Check for equivalence ignoring load/store alignment.
422 CompareIgnoringAlignment = 1<<0,
423 /// Check for equivalence treating a type and a vector of that type
425 CompareUsingScalarTypes = 1<<1
428 /// This function determines if the specified instruction executes the same
429 /// operation as the current one. This means that the opcodes, type, operand
430 /// types and any other factors affecting the operation must be the same. This
431 /// is similar to isIdenticalTo except the operands themselves don't have to
433 /// @returns true if the specified instruction is the same operation as
435 /// @brief Determine if one instruction is the same operation as another.
436 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const;
438 /// isUsedOutsideOfBlock - Return true if there are any uses of this
439 /// instruction in blocks other than the specified block. Note that PHI nodes
440 /// are considered to evaluate their operands in the corresponding predecessor
442 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
445 /// Methods for support type inquiry through isa, cast, and dyn_cast:
446 static inline bool classof(const Value *V) {
447 return V->getValueID() >= Value::InstructionVal;
450 //----------------------------------------------------------------------
451 // Exported enumerations.
453 enum TermOps { // These terminate basic blocks
454 #define FIRST_TERM_INST(N) TermOpsBegin = N,
455 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
456 #define LAST_TERM_INST(N) TermOpsEnd = N+1
457 #include "llvm/IR/Instruction.def"
461 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
462 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
463 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
464 #include "llvm/IR/Instruction.def"
468 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
469 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
470 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
471 #include "llvm/IR/Instruction.def"
475 #define FIRST_CAST_INST(N) CastOpsBegin = N,
476 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
477 #define LAST_CAST_INST(N) CastOpsEnd = N+1
478 #include "llvm/IR/Instruction.def"
482 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
483 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
484 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
485 #include "llvm/IR/Instruction.def"
488 // Shadow Value::setValueSubclassData with a private forwarding method so that
489 // subclasses cannot accidentally use it.
490 void setValueSubclassData(unsigned short D) {
491 Value::setValueSubclassData(D);
493 unsigned short getSubclassDataFromValue() const {
494 return Value::getSubclassDataFromValue();
497 void setHasMetadataHashEntry(bool V) {
498 setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
499 (V ? HasMetadataBit : 0));
502 friend class SymbolTableListTraits<Instruction>;
503 void setParent(BasicBlock *P);
505 // Instruction subclasses can stick up to 15 bits of stuff into the
506 // SubclassData field of instruction with these members.
508 // Verify that only the low 15 bits are used.
509 void setInstructionSubclassData(unsigned short D) {
510 assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
511 setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
514 unsigned getSubclassDataFromInstruction() const {
515 return getSubclassDataFromValue() & ~HasMetadataBit;
518 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
519 Instruction *InsertBefore = nullptr);
520 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
521 BasicBlock *InsertAtEnd);
524 /// Create a copy of this instruction.
525 Instruction *cloneImpl() const;
528 // Instruction* is only 4-byte aligned.
530 class PointerLikeTypeTraits<Instruction*> {
531 typedef Instruction* PT;
533 static inline void *getAsVoidPointer(PT P) { return P; }
534 static inline PT getFromVoidPointer(void *P) {
535 return static_cast<PT>(P);
537 enum { NumLowBitsAvailable = 2 };
540 } // End llvm namespace