1 //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file contains the declaration of the Instruction class, which is the 11 // base class for all of the LLVM instructions. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_IR_INSTRUCTION_H 16 #define LLVM_IR_INSTRUCTION_H 17 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" 23 24 namespace llvm { 25 26 class FastMathFlags; 27 class LLVMContext; 28 class MDNode; 29 class BasicBlock; 30 struct AAMDNodes; 31 32 template <> 33 struct SymbolTableListSentinelTraits<Instruction> 34 : public ilist_half_embedded_sentinel_traits<Instruction> {}; 35 36 class Instruction : public User, 37 public ilist_node_with_parent<Instruction, BasicBlock> { 38 void operator=(const Instruction &) = delete; 39 Instruction(const Instruction &) = delete; 40 41 BasicBlock *Parent; 42 DebugLoc DbgLoc; // 'dbg' Metadata cache. 43 44 enum { 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 48 }; 49 public: 50 // Out of line virtual method, so the vtable, etc has a home. 51 ~Instruction() override; 52 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());} 57 58 inline const BasicBlock *getParent() const { return Parent; } 59 inline BasicBlock *getParent() { return Parent; } 60 61 /// \brief Return the module owning the function this instruction belongs to 62 /// or nullptr it the function does not have a module. 63 /// 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; 67 Module *getModule(); 68 69 /// \brief Return the function this instruction belongs to. 70 /// 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(); 75 76 /// removeFromParent - This method unlinks 'this' from the containing basic 77 /// block, but does not delete it. 78 /// 79 void removeFromParent(); 80 81 /// eraseFromParent - This method unlinks 'this' from the containing basic 82 /// block and deletes it. 83 /// 84 /// \returns an iterator pointing to the element after the erased one 85 SymbolTableList<Instruction>::iterator eraseFromParent(); 86 87 /// Insert an unlinked instruction into a basic block immediately before 88 /// the specified instruction. 89 void insertBefore(Instruction *InsertPos); 90 91 /// Insert an unlinked instruction into a basic block immediately after the 92 /// specified instruction. 93 void insertAfter(Instruction *InsertPos); 94 95 /// moveBefore - Unlink this instruction from its current basic block and 96 /// insert it into the basic block that MovePos lives in, right before 97 /// MovePos. 98 void moveBefore(Instruction *MovePos); 99 100 //===--------------------------------------------------------------------===// 101 // Subclass classification. 102 //===--------------------------------------------------------------------===// 103 104 /// getOpcode() returns a member of one of the enums like Instruction::Add. 105 unsigned getOpcode() const { return getValueID() - InstructionVal; } 106 107 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()); } 112 bool isFuncletPad() const { return isFuncletPad(getOpcode()); } 113 114 static const char* getOpcodeName(unsigned OpCode); 115 116 static inline bool isTerminator(unsigned OpCode) { 117 return OpCode >= TermOpsBegin && OpCode < TermOpsEnd; 118 } 119 120 static inline bool isBinaryOp(unsigned Opcode) { 121 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd; 122 } 123 124 /// @brief Determine if the Opcode is one of the shift instructions. 125 static inline bool isShift(unsigned Opcode) { 126 return Opcode >= Shl && Opcode <= AShr; 127 } 128 129 /// isLogicalShift - Return true if this is a logical shift left or a logical 130 /// shift right. 131 inline bool isLogicalShift() const { 132 return getOpcode() == Shl || getOpcode() == LShr; 133 } 134 135 /// isArithmeticShift - Return true if this is an arithmetic shift right. 136 inline bool isArithmeticShift() const { 137 return getOpcode() == AShr; 138 } 139 140 /// @brief Determine if the OpCode is one of the CastInst instructions. 141 static inline bool isCast(unsigned OpCode) { 142 return OpCode >= CastOpsBegin && OpCode < CastOpsEnd; 143 } 144 145 /// @brief Determine if the OpCode is one of the FuncletPadInst instructions. 146 static inline bool isFuncletPad(unsigned OpCode) { 147 return OpCode >= FuncletPadOpsBegin && OpCode < FuncletPadOpsEnd; 148 } 149 150 //===--------------------------------------------------------------------===// 151 // Metadata manipulation. 152 //===--------------------------------------------------------------------===// 153 154 /// hasMetadata() - Return true if this instruction has any metadata attached 155 /// to it. 156 bool hasMetadata() const { return DbgLoc || hasMetadataHashEntry(); } 157 158 /// hasMetadataOtherThanDebugLoc - Return true if this instruction has 159 /// metadata attached to it other than a debug location. 160 bool hasMetadataOtherThanDebugLoc() const { 161 return hasMetadataHashEntry(); 162 } 163 164 /// getMetadata - Get the metadata of given kind attached to this Instruction. 165 /// If the metadata is not found then return null. 166 MDNode *getMetadata(unsigned KindID) const { 167 if (!hasMetadata()) return nullptr; 168 return getMetadataImpl(KindID); 169 } 170 171 /// getMetadata - Get the metadata of given kind attached to this Instruction. 172 /// If the metadata is not found then return null. 173 MDNode *getMetadata(StringRef Kind) const { 174 if (!hasMetadata()) return nullptr; 175 return getMetadataImpl(Kind); 176 } 177 178 /// getAllMetadata - Get all metadata attached to this Instruction. The first 179 /// element of each pair returned is the KindID, the second element is the 180 /// metadata value. This list is returned sorted by the KindID. 181 void 182 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 183 if (hasMetadata()) 184 getAllMetadataImpl(MDs); 185 } 186 187 /// getAllMetadataOtherThanDebugLoc - This does the same thing as 188 /// getAllMetadata, except that it filters out the debug location. 189 void getAllMetadataOtherThanDebugLoc( 190 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 191 if (hasMetadataOtherThanDebugLoc()) 192 getAllMetadataOtherThanDebugLocImpl(MDs); 193 } 194 195 /// getAAMetadata - Fills the AAMDNodes structure with AA metadata from 196 /// this instruction. When Merge is true, the existing AA metadata is 197 /// merged with that from this instruction providing the most-general result. 198 void getAAMetadata(AAMDNodes &N, bool Merge = false) const; 199 200 /// setMetadata - Set the metadata of the specified kind to the specified 201 /// node. This updates/replaces metadata if already present, or removes it if 202 /// Node is null. 203 void setMetadata(unsigned KindID, MDNode *Node); 204 void setMetadata(StringRef Kind, MDNode *Node); 205 206 /// Drop all unknown metadata except for debug locations. 207 /// @{ 208 /// Passes are required to drop metadata they don't understand. This is a 209 /// convenience method for passes to do so. 210 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs); 211 void dropUnknownNonDebugMetadata() { 212 return dropUnknownNonDebugMetadata(None); 213 } 214 void dropUnknownNonDebugMetadata(unsigned ID1) { 215 return dropUnknownNonDebugMetadata(makeArrayRef(ID1)); 216 } 217 void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) { 218 unsigned IDs[] = {ID1, ID2}; 219 return dropUnknownNonDebugMetadata(IDs); 220 } 221 /// @} 222 223 /// setAAMetadata - Sets the metadata on this instruction from the 224 /// AAMDNodes structure. 225 void setAAMetadata(const AAMDNodes &N); 226 227 /// setDebugLoc - Set the debug location information for this instruction. 228 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); } 229 230 /// getDebugLoc - Return the debug location for this node as a DebugLoc. 231 const DebugLoc &getDebugLoc() const { return DbgLoc; } 232 233 /// Set or clear the unsafe-algebra flag on this instruction, which must be an 234 /// operator which supports this flag. See LangRef.html for the meaning of 235 /// this flag. 236 void setHasUnsafeAlgebra(bool B); 237 238 /// Set or clear the no-nans flag on this instruction, which must be an 239 /// operator which supports this flag. See LangRef.html for the meaning of 240 /// this flag. 241 void setHasNoNaNs(bool B); 242 243 /// Set or clear the no-infs flag on this instruction, which must be an 244 /// operator which supports this flag. See LangRef.html for the meaning of 245 /// this flag. 246 void setHasNoInfs(bool B); 247 248 /// Set or clear the no-signed-zeros flag on this instruction, which must be 249 /// an operator which supports this flag. See LangRef.html for the meaning of 250 /// this flag. 251 void setHasNoSignedZeros(bool B); 252 253 /// Set or clear the allow-reciprocal flag on this instruction, which must be 254 /// an operator which supports this flag. See LangRef.html for the meaning of 255 /// this flag. 256 void setHasAllowReciprocal(bool B); 257 258 /// Convenience function for setting multiple fast-math flags on this 259 /// instruction, which must be an operator which supports these flags. See 260 /// LangRef.html for the meaning of these flags. 261 void setFastMathFlags(FastMathFlags FMF); 262 263 /// Convenience function for transferring all fast-math flag values to this 264 /// instruction, which must be an operator which supports these flags. See 265 /// LangRef.html for the meaning of these flags. 266 void copyFastMathFlags(FastMathFlags FMF); 267 268 /// Determine whether the unsafe-algebra flag is set. 269 bool hasUnsafeAlgebra() const; 270 271 /// Determine whether the no-NaNs flag is set. 272 bool hasNoNaNs() const; 273 274 /// Determine whether the no-infs flag is set. 275 bool hasNoInfs() const; 276 277 /// Determine whether the no-signed-zeros flag is set. 278 bool hasNoSignedZeros() const; 279 280 /// Determine whether the allow-reciprocal flag is set. 281 bool hasAllowReciprocal() const; 282 283 /// Convenience function for getting all the fast-math flags, which must be an 284 /// operator which supports these flags. See LangRef.html for the meaning of 285 /// these flags. 286 FastMathFlags getFastMathFlags() const; 287 288 /// Copy I's fast-math flags 289 void copyFastMathFlags(const Instruction *I); 290 291 private: 292 /// hasMetadataHashEntry - Return true if we have an entry in the on-the-side 293 /// metadata hash. 294 bool hasMetadataHashEntry() const { 295 return (getSubclassDataFromValue() & HasMetadataBit) != 0; 296 } 297 298 // These are all implemented in Metadata.cpp. 299 MDNode *getMetadataImpl(unsigned KindID) const; 300 MDNode *getMetadataImpl(StringRef Kind) const; 301 void 302 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; 303 void getAllMetadataOtherThanDebugLocImpl( 304 SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; 305 void clearMetadataHashEntries(); 306 public: 307 //===--------------------------------------------------------------------===// 308 // Predicates and helper methods. 309 //===--------------------------------------------------------------------===// 310 311 312 /// isAssociative - Return true if the instruction is associative: 313 /// 314 /// Associative operators satisfy: x op (y op z) === (x op y) op z 315 /// 316 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative. 317 /// 318 bool isAssociative() const; 319 static bool isAssociative(unsigned op); 320 321 /// isCommutative - Return true if the instruction is commutative: 322 /// 323 /// Commutative operators satisfy: (x op y) === (y op x) 324 /// 325 /// In LLVM, these are the associative operators, plus SetEQ and SetNE, when 326 /// applied to any type. 327 /// 328 bool isCommutative() const { return isCommutative(getOpcode()); } 329 static bool isCommutative(unsigned op); 330 331 /// isIdempotent - Return true if the instruction is idempotent: 332 /// 333 /// Idempotent operators satisfy: x op x === x 334 /// 335 /// In LLVM, the And and Or operators are idempotent. 336 /// 337 bool isIdempotent() const { return isIdempotent(getOpcode()); } 338 static bool isIdempotent(unsigned op); 339 340 /// isNilpotent - Return true if the instruction is nilpotent: 341 /// 342 /// Nilpotent operators satisfy: x op x === Id, 343 /// 344 /// where Id is the identity for the operator, i.e. a constant such that 345 /// x op Id === x and Id op x === x for all x. 346 /// 347 /// In LLVM, the Xor operator is nilpotent. 348 /// 349 bool isNilpotent() const { return isNilpotent(getOpcode()); } 350 static bool isNilpotent(unsigned op); 351 352 /// mayWriteToMemory - Return true if this instruction may modify memory. 353 /// 354 bool mayWriteToMemory() const; 355 356 /// mayReadFromMemory - Return true if this instruction may read memory. 357 /// 358 bool mayReadFromMemory() const; 359 360 /// mayReadOrWriteMemory - Return true if this instruction may read or 361 /// write memory. 362 /// 363 bool mayReadOrWriteMemory() const { 364 return mayReadFromMemory() || mayWriteToMemory(); 365 } 366 367 /// isAtomic - Return true if this instruction has an 368 /// AtomicOrdering of unordered or higher. 369 /// 370 bool isAtomic() const; 371 372 /// mayThrow - Return true if this instruction may throw an exception. 373 /// 374 bool mayThrow() const; 375 376 /// mayReturn - Return true if this is a function that may return. 377 /// this is true for all normal instructions. The only exception 378 /// is functions that are marked with the 'noreturn' attribute. 379 /// 380 bool mayReturn() const; 381 382 /// mayHaveSideEffects - Return true if the instruction may have side effects. 383 /// 384 /// Note that this does not consider malloc and alloca to have side 385 /// effects because the newly allocated memory is completely invisible to 386 /// instructions which don't use the returned value. For cases where this 387 /// matters, isSafeToSpeculativelyExecute may be more appropriate. 388 bool mayHaveSideEffects() const { 389 return mayWriteToMemory() || mayThrow() || !mayReturn(); 390 } 391 392 /// \brief Return true if the instruction is a variety of EH-block. 393 bool isEHPad() const { 394 switch (getOpcode()) { 395 case Instruction::CatchSwitch: 396 case Instruction::CatchPad: 397 case Instruction::CleanupPad: 398 case Instruction::LandingPad: 399 return true; 400 default: 401 return false; 402 } 403 } 404 405 /// clone() - Create a copy of 'this' instruction that is identical in all 406 /// ways except the following: 407 /// * The instruction has no parent 408 /// * The instruction has no name 409 /// 410 Instruction *clone() const; 411 412 /// isIdenticalTo - Return true if the specified instruction is exactly 413 /// identical to the current one. This means that all operands match and any 414 /// extra information (e.g. load is volatile) agree. 415 bool isIdenticalTo(const Instruction *I) const; 416 417 /// isIdenticalToWhenDefined - This is like isIdenticalTo, except that it 418 /// ignores the SubclassOptionalData flags, which specify conditions 419 /// under which the instruction's result is undefined. 420 bool isIdenticalToWhenDefined(const Instruction *I) const; 421 422 /// When checking for operation equivalence (using isSameOperationAs) it is 423 /// sometimes useful to ignore certain attributes. 424 enum OperationEquivalenceFlags { 425 /// Check for equivalence ignoring load/store alignment. 426 CompareIgnoringAlignment = 1<<0, 427 /// Check for equivalence treating a type and a vector of that type 428 /// as equivalent. 429 CompareUsingScalarTypes = 1<<1 430 }; 431 432 /// This function determines if the specified instruction executes the same 433 /// operation as the current one. This means that the opcodes, type, operand 434 /// types and any other factors affecting the operation must be the same. This 435 /// is similar to isIdenticalTo except the operands themselves don't have to 436 /// be identical. 437 /// @returns true if the specified instruction is the same operation as 438 /// the current one. 439 /// @brief Determine if one instruction is the same operation as another. 440 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const; 441 442 /// isUsedOutsideOfBlock - Return true if there are any uses of this 443 /// instruction in blocks other than the specified block. Note that PHI nodes 444 /// are considered to evaluate their operands in the corresponding predecessor 445 /// block. 446 bool isUsedOutsideOfBlock(const BasicBlock *BB) const; 447 448 449 /// Methods for support type inquiry through isa, cast, and dyn_cast: 450 static inline bool classof(const Value *V) { 451 return V->getValueID() >= Value::InstructionVal; 452 } 453 454 //---------------------------------------------------------------------- 455 // Exported enumerations. 456 // 457 enum TermOps { // These terminate basic blocks 458 #define FIRST_TERM_INST(N) TermOpsBegin = N, 459 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N, 460 #define LAST_TERM_INST(N) TermOpsEnd = N+1 461 #include "llvm/IR/Instruction.def" 462 }; 463 464 enum BinaryOps { 465 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N, 466 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N, 467 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1 468 #include "llvm/IR/Instruction.def" 469 }; 470 471 enum MemoryOps { 472 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N, 473 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N, 474 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1 475 #include "llvm/IR/Instruction.def" 476 }; 477 478 enum CastOps { 479 #define FIRST_CAST_INST(N) CastOpsBegin = N, 480 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N, 481 #define LAST_CAST_INST(N) CastOpsEnd = N+1 482 #include "llvm/IR/Instruction.def" 483 }; 484 485 enum FuncletPadOps { 486 #define FIRST_FUNCLETPAD_INST(N) FuncletPadOpsBegin = N, 487 #define HANDLE_FUNCLETPAD_INST(N, OPC, CLASS) OPC = N, 488 #define LAST_FUNCLETPAD_INST(N) FuncletPadOpsEnd = N+1 489 #include "llvm/IR/Instruction.def" 490 }; 491 492 enum OtherOps { 493 #define FIRST_OTHER_INST(N) OtherOpsBegin = N, 494 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N, 495 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1 496 #include "llvm/IR/Instruction.def" 497 }; 498 private: 499 // Shadow Value::setValueSubclassData with a private forwarding method so that 500 // subclasses cannot accidentally use it. 501 void setValueSubclassData(unsigned short D) { 502 Value::setValueSubclassData(D); 503 } 504 unsigned short getSubclassDataFromValue() const { 505 return Value::getSubclassDataFromValue(); 506 } 507 508 void setHasMetadataHashEntry(bool V) { 509 setValueSubclassData((getSubclassDataFromValue() & ~HasMetadataBit) | 510 (V ? HasMetadataBit : 0)); 511 } 512 513 friend class SymbolTableListTraits<Instruction>; 514 void setParent(BasicBlock *P); 515 protected: 516 // Instruction subclasses can stick up to 15 bits of stuff into the 517 // SubclassData field of instruction with these members. 518 519 // Verify that only the low 15 bits are used. 520 void setInstructionSubclassData(unsigned short D) { 521 assert((D & HasMetadataBit) == 0 && "Out of range value put into field"); 522 setValueSubclassData((getSubclassDataFromValue() & HasMetadataBit) | D); 523 } 524 525 unsigned getSubclassDataFromInstruction() const { 526 return getSubclassDataFromValue() & ~HasMetadataBit; 527 } 528 529 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 530 Instruction *InsertBefore = nullptr); 531 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 532 BasicBlock *InsertAtEnd); 533 534 private: 535 /// Create a copy of this instruction. 536 Instruction *cloneImpl() const; 537 }; 538 539 // Instruction* is only 4-byte aligned. 540 template<> 541 class PointerLikeTypeTraits<Instruction*> { 542 typedef Instruction* PT; 543 public: 544 static inline void *getAsVoidPointer(PT P) { return P; } 545 static inline PT getFromVoidPointer(void *P) { 546 return static_cast<PT>(P); 547 } 548 enum { NumLowBitsAvailable = 2 }; 549 }; 550 551 } // End llvm namespace 552 553 #endif 554