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 /// removeFromParent - This method unlinks 'this' from the containing basic
70 /// block, but does not delete it.
72 void removeFromParent();
74 /// eraseFromParent - This method unlinks 'this' from the containing basic
75 /// block and deletes it.
77 /// \returns an iterator pointing to the element after the erased one
78 SymbolTableList<Instruction>::iterator eraseFromParent();
80 /// Insert an unlinked instruction into a basic block immediately before
81 /// the specified instruction.
82 void insertBefore(Instruction *InsertPos);
84 /// Insert an unlinked instruction into a basic block immediately after the
85 /// specified instruction.
86 void insertAfter(Instruction *InsertPos);
88 /// moveBefore - Unlink this instruction from its current basic block and
89 /// insert it into the basic block that MovePos lives in, right before
91 void moveBefore(Instruction *MovePos);
93 //===--------------------------------------------------------------------===//
94 // Subclass classification.
95 //===--------------------------------------------------------------------===//
97 /// getOpcode() returns a member of one of the enums like Instruction::Add.
98 unsigned getOpcode() const { return getValueID() - InstructionVal; }
100 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
101 bool isTerminator() const { return isTerminator(getOpcode()); }
102 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
103 bool isShift() { return isShift(getOpcode()); }
104 bool isCast() const { return isCast(getOpcode()); }
106 static const char* getOpcodeName(unsigned OpCode);
108 static inline bool isTerminator(unsigned OpCode) {
109 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
112 static inline bool isBinaryOp(unsigned Opcode) {
113 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
116 /// @brief Determine if the Opcode is one of the shift instructions.
117 static inline bool isShift(unsigned Opcode) {
118 return Opcode >= Shl && Opcode <= AShr;
121 /// isLogicalShift - Return true if this is a logical shift left or a logical
123 inline bool isLogicalShift() const {
124 return getOpcode() == Shl || getOpcode() == LShr;
127 /// isArithmeticShift - Return true if this is an arithmetic shift right.
128 inline bool isArithmeticShift() const {
129 return getOpcode() == AShr;
132 /// @brief Determine if the OpCode is one of the CastInst instructions.
133 static inline bool isCast(unsigned OpCode) {
134 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
137 //===--------------------------------------------------------------------===//
138 // Metadata manipulation.
139 //===--------------------------------------------------------------------===//
141 /// hasMetadata() - Return true if this instruction has any metadata attached
143 bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); }
145 /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
146 /// metadata attached to it other than a debug location.
147 bool hasMetadataOtherThanDebugLoc() const {
148 return hasMetadataHashEntry();
151 /// getMetadata - Get the metadata of given kind attached to this Instruction.
152 /// If the metadata is not found then return null.
153 MDNode *getMetadata(unsigned KindID) const {
154 if (!hasMetadata()) return nullptr;
155 return getMetadataImpl(KindID);
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(StringRef Kind) const {
161 if (!hasMetadata()) return nullptr;
162 return getMetadataImpl(Kind);
165 /// getAllMetadata - Get all metadata attached to this Instruction. The first
166 /// element of each pair returned is the KindID, the second element is the
167 /// metadata value. This list is returned sorted by the KindID.
169 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
171 getAllMetadataImpl(MDs);
174 /// getAllMetadataOtherThanDebugLoc - This does the same thing as
175 /// getAllMetadata, except that it filters out the debug location.
176 void getAllMetadataOtherThanDebugLoc(
177 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
178 if (hasMetadataOtherThanDebugLoc())
179 getAllMetadataOtherThanDebugLocImpl(MDs);
182 /// getAAMetadata - Fills the AAMDNodes structure with AA metadata from
183 /// this instruction. When Merge is true, the existing AA metadata is
184 /// merged with that from this instruction providing the most-general result.
185 void getAAMetadata(AAMDNodes &N, bool Merge = false) const;
187 /// setMetadata - Set the metadata of the specified kind to the specified
188 /// node. This updates/replaces metadata if already present, or removes it if
190 void setMetadata(unsigned KindID, MDNode *Node);
191 void setMetadata(StringRef Kind, MDNode *Node);
193 /// Drop all unknown metadata except for debug locations.
195 /// Passes are required to drop metadata they don't understand. This is a
196 /// convenience method for passes to do so.
197 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs);
198 void dropUnknownNonDebugMetadata() {
199 return dropUnknownNonDebugMetadata(None);
201 void dropUnknownNonDebugMetadata(unsigned ID1) {
202 return dropUnknownNonDebugMetadata(makeArrayRef(ID1));
204 void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) {
205 unsigned IDs[] = {ID1, ID2};
206 return dropUnknownNonDebugMetadata(IDs);
210 /// setAAMetadata - Sets the metadata on this instruction from the
211 /// AAMDNodes structure.
212 void setAAMetadata(const AAMDNodes &N);
214 /// setDebugLoc - Set the debug location information for this instruction.
215 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }
217 /// getDebugLoc - Return the debug location for this node as a DebugLoc.
218 const DebugLoc &getDebugLoc() const { return DbgLoc; }
220 /// Set or clear the unsafe-algebra flag on this instruction, which must be an
221 /// operator which supports this flag. See LangRef.html for the meaning of
223 void setHasUnsafeAlgebra(bool B);
225 /// Set or clear the no-nans flag on this instruction, which must be an
226 /// operator which supports this flag. See LangRef.html for the meaning of
228 void setHasNoNaNs(bool B);
230 /// Set or clear the no-infs flag on this instruction, which must be an
231 /// operator which supports this flag. See LangRef.html for the meaning of
233 void setHasNoInfs(bool B);
235 /// Set or clear the no-signed-zeros flag on this instruction, which must be
236 /// an operator which supports this flag. See LangRef.html for the meaning of
238 void setHasNoSignedZeros(bool B);
240 /// Set or clear the allow-reciprocal flag on this instruction, which must be
241 /// an operator which supports this flag. See LangRef.html for the meaning of
243 void setHasAllowReciprocal(bool B);
245 /// Convenience function for setting multiple fast-math flags on this
246 /// instruction, which must be an operator which supports these flags. See
247 /// LangRef.html for the meaning of these flags.
248 void setFastMathFlags(FastMathFlags FMF);
250 /// Convenience function for transferring all fast-math flag values to this
251 /// instruction, which must be an operator which supports these flags. See
252 /// LangRef.html for the meaning of these flags.
253 void copyFastMathFlags(FastMathFlags FMF);
255 /// Determine whether the unsafe-algebra flag is set.
256 bool hasUnsafeAlgebra() const;
258 /// Determine whether the no-NaNs flag is set.
259 bool hasNoNaNs() const;
261 /// Determine whether the no-infs flag is set.
262 bool hasNoInfs() const;
264 /// Determine whether the no-signed-zeros flag is set.
265 bool hasNoSignedZeros() const;
267 /// Determine whether the allow-reciprocal flag is set.
268 bool hasAllowReciprocal() const;
270 /// Convenience function for getting all the fast-math flags, which must be an
271 /// operator which supports these flags. See LangRef.html for the meaning of
273 FastMathFlags getFastMathFlags() const;
275 /// Copy I's fast-math flags
276 void copyFastMathFlags(const Instruction *I);
279 /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
281 bool hasMetadataHashEntry() const {
282 return (getSubclassDataFromValue() & HasMetadataBit) != 0;
285 // These are all implemented in Metadata.cpp.
286 MDNode *getMetadataImpl(unsigned KindID) const;
287 MDNode *getMetadataImpl(StringRef Kind) const;
289 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
290 void getAllMetadataOtherThanDebugLocImpl(
291 SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
292 void clearMetadataHashEntries();
294 //===--------------------------------------------------------------------===//
295 // Predicates and helper methods.
296 //===--------------------------------------------------------------------===//
299 /// isAssociative - Return true if the instruction is associative:
301 /// Associative operators satisfy: x op (y op z) === (x op y) op z
303 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
305 bool isAssociative() const;
306 static bool isAssociative(unsigned op);
308 /// isCommutative - Return true if the instruction is commutative:
310 /// Commutative operators satisfy: (x op y) === (y op x)
312 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
313 /// applied to any type.
315 bool isCommutative() const { return isCommutative(getOpcode()); }
316 static bool isCommutative(unsigned op);
318 /// isIdempotent - Return true if the instruction is idempotent:
320 /// Idempotent operators satisfy: x op x === x
322 /// In LLVM, the And and Or operators are idempotent.
324 bool isIdempotent() const { return isIdempotent(getOpcode()); }
325 static bool isIdempotent(unsigned op);
327 /// isNilpotent - Return true if the instruction is nilpotent:
329 /// Nilpotent operators satisfy: x op x === Id,
331 /// where Id is the identity for the operator, i.e. a constant such that
332 /// x op Id === x and Id op x === x for all x.
334 /// In LLVM, the Xor operator is nilpotent.
336 bool isNilpotent() const { return isNilpotent(getOpcode()); }
337 static bool isNilpotent(unsigned op);
339 /// mayWriteToMemory - Return true if this instruction may modify memory.
341 bool mayWriteToMemory() const;
343 /// mayReadFromMemory - Return true if this instruction may read memory.
345 bool mayReadFromMemory() const;
347 /// mayReadOrWriteMemory - Return true if this instruction may read or
350 bool mayReadOrWriteMemory() const {
351 return mayReadFromMemory() || mayWriteToMemory();
354 /// isAtomic - Return true if this instruction has an
355 /// AtomicOrdering of unordered or higher.
357 bool isAtomic() const;
359 /// mayThrow - Return true if this instruction may throw an exception.
361 bool mayThrow() const;
363 /// mayReturn - Return true if this is a function that may return.
364 /// this is true for all normal instructions. The only exception
365 /// is functions that are marked with the 'noreturn' attribute.
367 bool mayReturn() const;
369 /// mayHaveSideEffects - Return true if the instruction may have side effects.
371 /// Note that this does not consider malloc and alloca to have side
372 /// effects because the newly allocated memory is completely invisible to
373 /// instructions which don't use the returned value. For cases where this
374 /// matters, isSafeToSpeculativelyExecute may be more appropriate.
375 bool mayHaveSideEffects() const {
376 return mayWriteToMemory() || mayThrow() || !mayReturn();
379 /// \brief Return true if the instruction is a variety of EH-block.
380 bool isEHPad() const {
381 switch (getOpcode()) {
382 case Instruction::CatchPad:
383 case Instruction::CatchEndPad:
384 case Instruction::CleanupPad:
385 case Instruction::CleanupEndPad:
386 case Instruction::LandingPad:
387 case Instruction::TerminatePad:
394 /// clone() - Create a copy of 'this' instruction that is identical in all
395 /// ways except the following:
396 /// * The instruction has no parent
397 /// * The instruction has no name
399 Instruction *clone() const;
401 /// isIdenticalTo - Return true if the specified instruction is exactly
402 /// identical to the current one. This means that all operands match and any
403 /// extra information (e.g. load is volatile) agree.
404 bool isIdenticalTo(const Instruction *I) const;
406 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
407 /// ignores the SubclassOptionalData flags, which specify conditions
408 /// under which the instruction's result is undefined.
409 bool isIdenticalToWhenDefined(const Instruction *I) const;
411 /// When checking for operation equivalence (using isSameOperationAs) it is
412 /// sometimes useful to ignore certain attributes.
413 enum OperationEquivalenceFlags {
414 /// Check for equivalence ignoring load/store alignment.
415 CompareIgnoringAlignment = 1<<0,
416 /// Check for equivalence treating a type and a vector of that type
418 CompareUsingScalarTypes = 1<<1
421 /// This function determines if the specified instruction executes the same
422 /// operation as the current one. This means that the opcodes, type, operand
423 /// types and any other factors affecting the operation must be the same. This
424 /// is similar to isIdenticalTo except the operands themselves don't have to
426 /// @returns true if the specified instruction is the same operation as
428 /// @brief Determine if one instruction is the same operation as another.
429 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const;
431 /// isUsedOutsideOfBlock - Return true if there are any uses of this
432 /// instruction in blocks other than the specified block. Note that PHI nodes
433 /// are considered to evaluate their operands in the corresponding predecessor
435 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
438 /// Methods for support type inquiry through isa, cast, and dyn_cast:
439 static inline bool classof(const Value *V) {
440 return V->getValueID() >= Value::InstructionVal;
443 //----------------------------------------------------------------------
444 // Exported enumerations.
446 enum TermOps { // These terminate basic blocks
447 #define FIRST_TERM_INST(N) TermOpsBegin = N,
448 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
449 #define LAST_TERM_INST(N) TermOpsEnd = N+1
450 #include "llvm/IR/Instruction.def"
454 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
455 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
456 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
457 #include "llvm/IR/Instruction.def"
461 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
462 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
463 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
464 #include "llvm/IR/Instruction.def"
468 #define FIRST_CAST_INST(N) CastOpsBegin = N,
469 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
470 #define LAST_CAST_INST(N) CastOpsEnd = N+1
471 #include "llvm/IR/Instruction.def"
475 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
476 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
477 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
478 #include "llvm/IR/Instruction.def"
481 // Shadow Value::setValueSubclassData with a private forwarding method so that
482 // subclasses cannot accidentally use it.
483 void setValueSubclassData(unsigned short D) {
484 Value::setValueSubclassData(D);
486 unsigned short getSubclassDataFromValue() const {
487 return Value::getSubclassDataFromValue();
490 void setHasMetadataHashEntry(bool V) {
491 setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
492 (V ? HasMetadataBit : 0));
495 friend class SymbolTableListTraits<Instruction>;
496 void setParent(BasicBlock *P);
498 // Instruction subclasses can stick up to 15 bits of stuff into the
499 // SubclassData field of instruction with these members.
501 // Verify that only the low 15 bits are used.
502 void setInstructionSubclassData(unsigned short D) {
503 assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
504 setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
507 unsigned getSubclassDataFromInstruction() const {
508 return getSubclassDataFromValue() & ~HasMetadataBit;
511 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
512 Instruction *InsertBefore = nullptr);
513 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
514 BasicBlock *InsertAtEnd);
517 /// Create a copy of this instruction.
518 Instruction *cloneImpl() const;
521 // Instruction* is only 4-byte aligned.
523 class PointerLikeTypeTraits<Instruction*> {
524 typedef Instruction* PT;
526 static inline void *getAsVoidPointer(PT P) { return P; }
527 static inline PT getFromVoidPointer(void *P) {
528 return static_cast<PT>(P);
530 enum { NumLowBitsAvailable = 2 };
533 } // End llvm namespace