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, public ilist_node<Instruction> {
37 void operator=(const Instruction &) = delete;
38 Instruction(const Instruction &) = delete;
41 DebugLoc DbgLoc; // 'dbg' Metadata cache.
44 /// HasMetadataBit - This is a bit stored in the SubClassData field which
45 /// indicates whether this instruction has metadata attached to it or not.
46 HasMetadataBit = 1 << 15
49 // Out of line virtual method, so the vtable, etc has a home.
50 ~Instruction() override;
52 /// user_back - Specialize the methods defined in Value, as we know that an
53 /// instruction can only be used by other instructions.
54 Instruction *user_back() { return cast<Instruction>(*user_begin());}
55 const Instruction *user_back() const { return cast<Instruction>(*user_begin());}
57 inline const BasicBlock *getParent() const { return Parent; }
58 inline BasicBlock *getParent() { return Parent; }
60 /// \brief Return the module owning the function this instruction belongs to
61 /// or nullptr it the function does not have a module.
63 /// Note: this is undefined behavior if the instruction does not have a
64 /// parent, or the parent basic block does not have a parent function.
65 const Module *getModule() const;
68 /// removeFromParent - This method unlinks 'this' from the containing basic
69 /// block, but does not delete it.
71 void removeFromParent();
73 /// eraseFromParent - This method unlinks 'this' from the containing basic
74 /// block and deletes it.
76 /// \returns an iterator pointing to the element after the erased one
77 SymbolTableList<Instruction>::iterator eraseFromParent();
79 /// Insert an unlinked instruction into a basic block immediately before
80 /// the specified instruction.
81 void insertBefore(Instruction *InsertPos);
83 /// Insert an unlinked instruction into a basic block immediately after the
84 /// specified instruction.
85 void insertAfter(Instruction *InsertPos);
87 /// moveBefore - Unlink this instruction from its current basic block and
88 /// insert it into the basic block that MovePos lives in, right before
90 void moveBefore(Instruction *MovePos);
92 //===--------------------------------------------------------------------===//
93 // Subclass classification.
94 //===--------------------------------------------------------------------===//
96 /// getOpcode() returns a member of one of the enums like Instruction::Add.
97 unsigned getOpcode() const { return getValueID() - InstructionVal; }
99 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); }
100 bool isTerminator() const { return isTerminator(getOpcode()); }
101 bool isBinaryOp() const { return isBinaryOp(getOpcode()); }
102 bool isShift() { return isShift(getOpcode()); }
103 bool isCast() const { return isCast(getOpcode()); }
105 static const char* getOpcodeName(unsigned OpCode);
107 static inline bool isTerminator(unsigned OpCode) {
108 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd;
111 static inline bool isBinaryOp(unsigned Opcode) {
112 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd;
115 /// @brief Determine if the Opcode is one of the shift instructions.
116 static inline bool isShift(unsigned Opcode) {
117 return Opcode >= Shl && Opcode <= AShr;
120 /// isLogicalShift - Return true if this is a logical shift left or a logical
122 inline bool isLogicalShift() const {
123 return getOpcode() == Shl || getOpcode() == LShr;
126 /// isArithmeticShift - Return true if this is an arithmetic shift right.
127 inline bool isArithmeticShift() const {
128 return getOpcode() == AShr;
131 /// @brief Determine if the OpCode is one of the CastInst instructions.
132 static inline bool isCast(unsigned OpCode) {
133 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd;
136 //===--------------------------------------------------------------------===//
137 // Metadata manipulation.
138 //===--------------------------------------------------------------------===//
140 /// hasMetadata() - Return true if this instruction has any metadata attached
142 bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); }
144 /// hasMetadataOtherThanDebugLoc - Return true if this instruction has
145 /// metadata attached to it other than a debug location.
146 bool hasMetadataOtherThanDebugLoc() const {
147 return hasMetadataHashEntry();
150 /// getMetadata - Get the metadata of given kind attached to this Instruction.
151 /// If the metadata is not found then return null.
152 MDNode *getMetadata(unsigned KindID) const {
153 if (!hasMetadata()) return nullptr;
154 return getMetadataImpl(KindID);
157 /// getMetadata - Get the metadata of given kind attached to this Instruction.
158 /// If the metadata is not found then return null.
159 MDNode *getMetadata(StringRef Kind) const {
160 if (!hasMetadata()) return nullptr;
161 return getMetadataImpl(Kind);
164 /// getAllMetadata - Get all metadata attached to this Instruction. The first
165 /// element of each pair returned is the KindID, the second element is the
166 /// metadata value. This list is returned sorted by the KindID.
168 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
170 getAllMetadataImpl(MDs);
173 /// getAllMetadataOtherThanDebugLoc - This does the same thing as
174 /// getAllMetadata, except that it filters out the debug location.
175 void getAllMetadataOtherThanDebugLoc(
176 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
177 if (hasMetadataOtherThanDebugLoc())
178 getAllMetadataOtherThanDebugLocImpl(MDs);
181 /// getAAMetadata - Fills the AAMDNodes structure with AA metadata from
182 /// this instruction. When Merge is true, the existing AA metadata is
183 /// merged with that from this instruction providing the most-general result.
184 void getAAMetadata(AAMDNodes &N, bool Merge = false) const;
186 /// setMetadata - Set the metadata of the specified kind to the specified
187 /// node. This updates/replaces metadata if already present, or removes it if
189 void setMetadata(unsigned KindID, MDNode *Node);
190 void setMetadata(StringRef Kind, MDNode *Node);
192 /// Drop all unknown metadata except for debug locations.
194 /// Passes are required to drop metadata they don't understand. This is a
195 /// convenience method for passes to do so.
196 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs);
197 void dropUnknownNonDebugMetadata() {
198 return dropUnknownNonDebugMetadata(None);
200 void dropUnknownNonDebugMetadata(unsigned ID1) {
201 return dropUnknownNonDebugMetadata(makeArrayRef(ID1));
203 void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) {
204 unsigned IDs[] = {ID1, ID2};
205 return dropUnknownNonDebugMetadata(IDs);
209 /// setAAMetadata - Sets the metadata on this instruction from the
210 /// AAMDNodes structure.
211 void setAAMetadata(const AAMDNodes &N);
213 /// setDebugLoc - Set the debug location information for this instruction.
214 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); }
216 /// getDebugLoc - Return the debug location for this node as a DebugLoc.
217 const DebugLoc &getDebugLoc() const { return DbgLoc; }
219 /// Set or clear the unsafe-algebra flag on this instruction, which must be an
220 /// operator which supports this flag. See LangRef.html for the meaning of
222 void setHasUnsafeAlgebra(bool B);
224 /// Set or clear the no-nans flag on this instruction, which must be an
225 /// operator which supports this flag. See LangRef.html for the meaning of
227 void setHasNoNaNs(bool B);
229 /// Set or clear the no-infs flag on this instruction, which must be an
230 /// operator which supports this flag. See LangRef.html for the meaning of
232 void setHasNoInfs(bool B);
234 /// Set or clear the no-signed-zeros flag on this instruction, which must be
235 /// an operator which supports this flag. See LangRef.html for the meaning of
237 void setHasNoSignedZeros(bool B);
239 /// Set or clear the allow-reciprocal flag on this instruction, which must be
240 /// an operator which supports this flag. See LangRef.html for the meaning of
242 void setHasAllowReciprocal(bool B);
244 /// Convenience function for setting multiple fast-math flags on this
245 /// instruction, which must be an operator which supports these flags. See
246 /// LangRef.html for the meaning of these flags.
247 void setFastMathFlags(FastMathFlags FMF);
249 /// Convenience function for transferring all fast-math flag values to this
250 /// instruction, which must be an operator which supports these flags. See
251 /// LangRef.html for the meaning of these flags.
252 void copyFastMathFlags(FastMathFlags FMF);
254 /// Determine whether the unsafe-algebra flag is set.
255 bool hasUnsafeAlgebra() const;
257 /// Determine whether the no-NaNs flag is set.
258 bool hasNoNaNs() const;
260 /// Determine whether the no-infs flag is set.
261 bool hasNoInfs() const;
263 /// Determine whether the no-signed-zeros flag is set.
264 bool hasNoSignedZeros() const;
266 /// Determine whether the allow-reciprocal flag is set.
267 bool hasAllowReciprocal() const;
269 /// Convenience function for getting all the fast-math flags, which must be an
270 /// operator which supports these flags. See LangRef.html for the meaning of
272 FastMathFlags getFastMathFlags() const;
274 /// Copy I's fast-math flags
275 void copyFastMathFlags(const Instruction *I);
278 /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side
280 bool hasMetadataHashEntry() const {
281 return (getSubclassDataFromValue() & HasMetadataBit) != 0;
284 // These are all implemented in Metadata.cpp.
285 MDNode *getMetadataImpl(unsigned KindID) const;
286 MDNode *getMetadataImpl(StringRef Kind) const;
288 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
289 void getAllMetadataOtherThanDebugLocImpl(
290 SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const;
291 void clearMetadataHashEntries();
293 //===--------------------------------------------------------------------===//
294 // Predicates and helper methods.
295 //===--------------------------------------------------------------------===//
298 /// isAssociative - Return true if the instruction is associative:
300 /// Associative operators satisfy: x op (y op z) === (x op y) op z
302 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative.
304 bool isAssociative() const;
305 static bool isAssociative(unsigned op);
307 /// isCommutative - Return true if the instruction is commutative:
309 /// Commutative operators satisfy: (x op y) === (y op x)
311 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when
312 /// applied to any type.
314 bool isCommutative() const { return isCommutative(getOpcode()); }
315 static bool isCommutative(unsigned op);
317 /// isIdempotent - Return true if the instruction is idempotent:
319 /// Idempotent operators satisfy: x op x === x
321 /// In LLVM, the And and Or operators are idempotent.
323 bool isIdempotent() const { return isIdempotent(getOpcode()); }
324 static bool isIdempotent(unsigned op);
326 /// isNilpotent - Return true if the instruction is nilpotent:
328 /// Nilpotent operators satisfy: x op x === Id,
330 /// where Id is the identity for the operator, i.e. a constant such that
331 /// x op Id === x and Id op x === x for all x.
333 /// In LLVM, the Xor operator is nilpotent.
335 bool isNilpotent() const { return isNilpotent(getOpcode()); }
336 static bool isNilpotent(unsigned op);
338 /// mayWriteToMemory - Return true if this instruction may modify memory.
340 bool mayWriteToMemory() const;
342 /// mayReadFromMemory - Return true if this instruction may read memory.
344 bool mayReadFromMemory() const;
346 /// mayReadOrWriteMemory - Return true if this instruction may read or
349 bool mayReadOrWriteMemory() const {
350 return mayReadFromMemory() || mayWriteToMemory();
353 /// isAtomic - Return true if this instruction has an
354 /// AtomicOrdering of unordered or higher.
356 bool isAtomic() const;
358 /// mayThrow - Return true if this instruction may throw an exception.
360 bool mayThrow() const;
362 /// mayReturn - Return true if this is a function that may return.
363 /// this is true for all normal instructions. The only exception
364 /// is functions that are marked with the 'noreturn' attribute.
366 bool mayReturn() const;
368 /// mayHaveSideEffects - Return true if the instruction may have side effects.
370 /// Note that this does not consider malloc and alloca to have side
371 /// effects because the newly allocated memory is completely invisible to
372 /// instructions which don't use the returned value. For cases where this
373 /// matters, isSafeToSpeculativelyExecute may be more appropriate.
374 bool mayHaveSideEffects() const {
375 return mayWriteToMemory() || mayThrow() || !mayReturn();
378 /// \brief Return true if the instruction is a variety of EH-block.
379 bool isEHPad() const {
380 switch (getOpcode()) {
381 case Instruction::CatchPad:
382 case Instruction::CatchEndPad:
383 case Instruction::CleanupPad:
384 case Instruction::CleanupEndPad:
385 case Instruction::LandingPad:
386 case Instruction::TerminatePad:
393 /// clone() - Create a copy of 'this' instruction that is identical in all
394 /// ways except the following:
395 /// * The instruction has no parent
396 /// * The instruction has no name
398 Instruction *clone() const;
400 /// isIdenticalTo - Return true if the specified instruction is exactly
401 /// identical to the current one. This means that all operands match and any
402 /// extra information (e.g. load is volatile) agree.
403 bool isIdenticalTo(const Instruction *I) const;
405 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it
406 /// ignores the SubclassOptionalData flags, which specify conditions
407 /// under which the instruction's result is undefined.
408 bool isIdenticalToWhenDefined(const Instruction *I) const;
410 /// When checking for operation equivalence (using isSameOperationAs) it is
411 /// sometimes useful to ignore certain attributes.
412 enum OperationEquivalenceFlags {
413 /// Check for equivalence ignoring load/store alignment.
414 CompareIgnoringAlignment = 1<<0,
415 /// Check for equivalence treating a type and a vector of that type
417 CompareUsingScalarTypes = 1<<1
420 /// This function determines if the specified instruction executes the same
421 /// operation as the current one. This means that the opcodes, type, operand
422 /// types and any other factors affecting the operation must be the same. This
423 /// is similar to isIdenticalTo except the operands themselves don't have to
425 /// @returns true if the specified instruction is the same operation as
427 /// @brief Determine if one instruction is the same operation as another.
428 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const;
430 /// isUsedOutsideOfBlock - Return true if there are any uses of this
431 /// instruction in blocks other than the specified block. Note that PHI nodes
432 /// are considered to evaluate their operands in the corresponding predecessor
434 bool isUsedOutsideOfBlock(const BasicBlock *BB) const;
437 /// Methods for support type inquiry through isa, cast, and dyn_cast:
438 static inline bool classof(const Value *V) {
439 return V->getValueID() >= Value::InstructionVal;
442 //----------------------------------------------------------------------
443 // Exported enumerations.
445 enum TermOps { // These terminate basic blocks
446 #define FIRST_TERM_INST(N) TermOpsBegin = N,
447 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N,
448 #define LAST_TERM_INST(N) TermOpsEnd = N+1
449 #include "llvm/IR/Instruction.def"
453 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N,
454 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N,
455 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1
456 #include "llvm/IR/Instruction.def"
460 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N,
461 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N,
462 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1
463 #include "llvm/IR/Instruction.def"
467 #define FIRST_CAST_INST(N) CastOpsBegin = N,
468 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N,
469 #define LAST_CAST_INST(N) CastOpsEnd = N+1
470 #include "llvm/IR/Instruction.def"
474 #define FIRST_OTHER_INST(N) OtherOpsBegin = N,
475 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N,
476 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1
477 #include "llvm/IR/Instruction.def"
480 // Shadow Value::setValueSubclassData with a private forwarding method so that
481 // subclasses cannot accidentally use it.
482 void setValueSubclassData(unsigned short D) {
483 Value::setValueSubclassData(D);
485 unsigned short getSubclassDataFromValue() const {
486 return Value::getSubclassDataFromValue();
489 void setHasMetadataHashEntry(bool V) {
490 setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) |
491 (V ? HasMetadataBit : 0));
494 friend class SymbolTableListTraits<Instruction>;
495 void setParent(BasicBlock *P);
497 // Instruction subclasses can stick up to 15 bits of stuff into the
498 // SubclassData field of instruction with these members.
500 // Verify that only the low 15 bits are used.
501 void setInstructionSubclassData(unsigned short D) {
502 assert((D & HasMetadataBit) == 0 && "Out of range value put into field");
503 setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D);
506 unsigned getSubclassDataFromInstruction() const {
507 return getSubclassDataFromValue() & ~HasMetadataBit;
510 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
511 Instruction *InsertBefore = nullptr);
512 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps,
513 BasicBlock *InsertAtEnd);
516 /// Create a copy of this instruction.
517 Instruction *cloneImpl() const;
520 // Instruction* is only 4-byte aligned.
522 class PointerLikeTypeTraits<Instruction*> {
523 typedef Instruction* PT;
525 static inline void *getAsVoidPointer(PT P) { return P; }
526 static inline PT getFromVoidPointer(void *P) {
527 return static_cast<PT>(P);
529 enum { NumLowBitsAvailable = 2 };
532 } // End llvm namespace