1 //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file contains the declaration of the Instruction class, which is the 10 // base class for all of the LLVM instructions. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_IR_INSTRUCTION_H 15 #define LLVM_IR_INSTRUCTION_H 16 17 #include "llvm/ADT/ArrayRef.h" 18 #include "llvm/ADT/Bitfields.h" 19 #include "llvm/ADT/StringRef.h" 20 #include "llvm/ADT/ilist_node.h" 21 #include "llvm/IR/DebugLoc.h" 22 #include "llvm/IR/SymbolTableListTraits.h" 23 #include "llvm/IR/User.h" 24 #include "llvm/IR/Value.h" 25 #include "llvm/Support/AtomicOrdering.h" 26 #include <cstdint> 27 #include <utility> 28 29 namespace llvm { 30 31 class BasicBlock; 32 class DataLayout; 33 class DbgMarker; 34 class FastMathFlags; 35 class MDNode; 36 class Module; 37 struct AAMDNodes; 38 class DbgMarker; 39 class DbgRecord; 40 41 template <> struct ilist_alloc_traits<Instruction> { 42 static inline void deleteNode(Instruction *V); 43 }; 44 45 iterator_range<simple_ilist<DbgRecord>::iterator> 46 getDbgRecordRange(DbgMarker *); 47 48 class InsertPosition { 49 using InstListType = SymbolTableList<Instruction, ilist_iterator_bits<true>, 50 ilist_parent<BasicBlock>>; 51 InstListType::iterator InsertAt; 52 53 public: 54 InsertPosition(std::nullptr_t) : InsertAt() {} 55 // LLVM_DEPRECATED("Use BasicBlock::iterators for insertion instead", 56 // "BasicBlock::iterator") 57 InsertPosition(Instruction *InsertBefore); 58 InsertPosition(BasicBlock *InsertAtEnd); 59 InsertPosition(InstListType::iterator InsertAt) : InsertAt(InsertAt) {} 60 operator InstListType::iterator() const { return InsertAt; } 61 bool isValid() const { return InsertAt.isValid(); } 62 BasicBlock *getBasicBlock() { return InsertAt.getNodeParent(); } 63 }; 64 65 class Instruction : public User, 66 public ilist_node_with_parent<Instruction, BasicBlock, 67 ilist_iterator_bits<true>, 68 ilist_parent<BasicBlock>> { 69 public: 70 using InstListType = SymbolTableList<Instruction, ilist_iterator_bits<true>, 71 ilist_parent<BasicBlock>>; 72 73 private: 74 DebugLoc DbgLoc; // 'dbg' Metadata cache. 75 76 /// Relative order of this instruction in its parent basic block. Used for 77 /// O(1) local dominance checks between instructions. 78 mutable unsigned Order = 0; 79 80 public: 81 /// Optional marker recording the position for debugging information that 82 /// takes effect immediately before this instruction. Null unless there is 83 /// debugging information present. 84 DbgMarker *DebugMarker = nullptr; 85 86 /// Clone any debug-info attached to \p From onto this instruction. Used to 87 /// copy debugging information from one block to another, when copying entire 88 /// blocks. \see DebugProgramInstruction.h , because the ordering of 89 /// DbgRecords is still important, fine grain control of which instructions 90 /// are moved and where they go is necessary. 91 /// \p From The instruction to clone debug-info from. 92 /// \p from_here Optional iterator to limit DbgRecords cloned to be a range 93 /// from 94 /// from_here to end(). 95 /// \p InsertAtHead Whether the cloned DbgRecords should be placed at the end 96 /// or the beginning of existing DbgRecords attached to this. 97 /// \returns A range over the newly cloned DbgRecords. 98 iterator_range<simple_ilist<DbgRecord>::iterator> cloneDebugInfoFrom( 99 const Instruction *From, 100 std::optional<simple_ilist<DbgRecord>::iterator> FromHere = std::nullopt, 101 bool InsertAtHead = false); 102 103 /// Return a range over the DbgRecords attached to this instruction. 104 iterator_range<simple_ilist<DbgRecord>::iterator> getDbgRecordRange() const { 105 return llvm::getDbgRecordRange(DebugMarker); 106 } 107 108 /// Return an iterator to the position of the "Next" DbgRecord after this 109 /// instruction, or std::nullopt. This is the position to pass to 110 /// BasicBlock::reinsertInstInDbgRecords when re-inserting an instruction. 111 std::optional<simple_ilist<DbgRecord>::iterator> getDbgReinsertionPosition(); 112 113 /// Returns true if any DbgRecords are attached to this instruction. 114 bool hasDbgRecords() const; 115 116 /// Transfer any DbgRecords on the position \p It onto this instruction, 117 /// by simply adopting the sequence of DbgRecords (which is efficient) if 118 /// possible, by merging two sequences otherwise. 119 void adoptDbgRecords(BasicBlock *BB, InstListType::iterator It, 120 bool InsertAtHead); 121 122 /// Erase any DbgRecords attached to this instruction. 123 void dropDbgRecords(); 124 125 /// Erase a single DbgRecord \p I that is attached to this instruction. 126 void dropOneDbgRecord(DbgRecord *I); 127 128 /// Handle the debug-info implications of this instruction being removed. Any 129 /// attached DbgRecords need to "fall" down onto the next instruction. 130 void handleMarkerRemoval(); 131 132 protected: 133 // The 15 first bits of `Value::SubclassData` are available for subclasses of 134 // `Instruction` to use. 135 using OpaqueField = Bitfield::Element<uint16_t, 0, 15>; 136 137 // Template alias so that all Instruction storing alignment use the same 138 // definiton. 139 // Valid alignments are powers of two from 2^0 to 2^MaxAlignmentExponent = 140 // 2^32. We store them as Log2(Alignment), so we need 6 bits to encode the 33 141 // possible values. 142 template <unsigned Offset> 143 using AlignmentBitfieldElementT = 144 typename Bitfield::Element<unsigned, Offset, 6, 145 Value::MaxAlignmentExponent>; 146 147 template <unsigned Offset> 148 using BoolBitfieldElementT = typename Bitfield::Element<bool, Offset, 1>; 149 150 template <unsigned Offset> 151 using AtomicOrderingBitfieldElementT = 152 typename Bitfield::Element<AtomicOrdering, Offset, 3, 153 AtomicOrdering::LAST>; 154 155 private: 156 // The last bit is used to store whether the instruction has metadata attached 157 // or not. 158 using HasMetadataField = Bitfield::Element<bool, 15, 1>; 159 160 protected: 161 ~Instruction(); // Use deleteValue() to delete a generic Instruction. 162 163 public: 164 Instruction(const Instruction &) = delete; 165 Instruction &operator=(const Instruction &) = delete; 166 167 /// Specialize the methods defined in Value, as we know that an instruction 168 /// can only be used by other instructions. 169 Instruction *user_back() { return cast<Instruction>(*user_begin());} 170 const Instruction *user_back() const { return cast<Instruction>(*user_begin());} 171 172 /// Return the module owning the function this instruction belongs to 173 /// or nullptr it the function does not have a module. 174 /// 175 /// Note: this is undefined behavior if the instruction does not have a 176 /// parent, or the parent basic block does not have a parent function. 177 const Module *getModule() const; 178 Module *getModule() { 179 return const_cast<Module *>( 180 static_cast<const Instruction *>(this)->getModule()); 181 } 182 183 /// Return the function this instruction belongs to. 184 /// 185 /// Note: it is undefined behavior to call this on an instruction not 186 /// currently inserted into a function. 187 const Function *getFunction() const; 188 Function *getFunction() { 189 return const_cast<Function *>( 190 static_cast<const Instruction *>(this)->getFunction()); 191 } 192 193 /// Get the data layout of the module this instruction belongs to. 194 /// 195 /// Requires the instruction to have a parent module. 196 const DataLayout &getDataLayout() const; 197 198 /// This method unlinks 'this' from the containing basic block, but does not 199 /// delete it. 200 void removeFromParent(); 201 202 /// This method unlinks 'this' from the containing basic block and deletes it. 203 /// 204 /// \returns an iterator pointing to the element after the erased one 205 InstListType::iterator eraseFromParent(); 206 207 /// Insert an unlinked instruction into a basic block immediately before 208 /// the specified instruction. 209 void insertBefore(Instruction *InsertPos); 210 void insertBefore(InstListType::iterator InsertPos); 211 212 /// Insert an unlinked instruction into a basic block immediately after the 213 /// specified instruction. 214 void insertAfter(Instruction *InsertPos); 215 216 /// Inserts an unlinked instruction into \p ParentBB at position \p It and 217 /// returns the iterator of the inserted instruction. 218 InstListType::iterator insertInto(BasicBlock *ParentBB, 219 InstListType::iterator It); 220 221 void insertBefore(BasicBlock &BB, InstListType::iterator InsertPos); 222 223 /// Unlink this instruction from its current basic block and insert it into 224 /// the basic block that MovePos lives in, right before MovePos. 225 void moveBefore(Instruction *MovePos); 226 227 /// Perform a \ref moveBefore operation, while signalling that the caller 228 /// intends to preserve the original ordering of instructions. This implicitly 229 /// means that any adjacent debug-info should move with this instruction. 230 /// This method is currently a no-op placeholder, but it will become meaningful 231 /// when the "RemoveDIs" project is enabled. 232 void moveBeforePreserving(Instruction *MovePos); 233 234 private: 235 /// RemoveDIs project: all other moves implemented with this method, 236 /// centralising debug-info updates into one place. 237 void moveBeforeImpl(BasicBlock &BB, InstListType::iterator I, bool Preserve); 238 239 public: 240 /// Unlink this instruction and insert into BB before I. 241 /// 242 /// \pre I is a valid iterator into BB. 243 void moveBefore(BasicBlock &BB, InstListType::iterator I); 244 245 /// (See other overload for moveBeforePreserving). 246 void moveBeforePreserving(BasicBlock &BB, InstListType::iterator I); 247 248 /// Unlink this instruction from its current basic block and insert it into 249 /// the basic block that MovePos lives in, right after MovePos. 250 void moveAfter(Instruction *MovePos); 251 252 /// See \ref moveBeforePreserving . 253 void moveAfterPreserving(Instruction *MovePos); 254 255 /// Given an instruction Other in the same basic block as this instruction, 256 /// return true if this instruction comes before Other. In this worst case, 257 /// this takes linear time in the number of instructions in the block. The 258 /// results are cached, so in common cases when the block remains unmodified, 259 /// it takes constant time. 260 bool comesBefore(const Instruction *Other) const; 261 262 /// Get the first insertion point at which the result of this instruction 263 /// is defined. This is *not* the directly following instruction in a number 264 /// of cases, e.g. phi nodes or terminators that return values. This function 265 /// may return null if the insertion after the definition is not possible, 266 /// e.g. due to a catchswitch terminator. 267 std::optional<InstListType::iterator> getInsertionPointAfterDef(); 268 269 //===--------------------------------------------------------------------===// 270 // Subclass classification. 271 //===--------------------------------------------------------------------===// 272 273 /// Returns a member of one of the enums like Instruction::Add. 274 unsigned getOpcode() const { return getValueID() - InstructionVal; } 275 276 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); } 277 bool isTerminator() const { return isTerminator(getOpcode()); } 278 bool isUnaryOp() const { return isUnaryOp(getOpcode()); } 279 bool isBinaryOp() const { return isBinaryOp(getOpcode()); } 280 bool isIntDivRem() const { return isIntDivRem(getOpcode()); } 281 bool isShift() const { return isShift(getOpcode()); } 282 bool isCast() const { return isCast(getOpcode()); } 283 bool isFuncletPad() const { return isFuncletPad(getOpcode()); } 284 bool isSpecialTerminator() const { return isSpecialTerminator(getOpcode()); } 285 286 /// It checks if this instruction is the only user of at least one of 287 /// its operands. 288 bool isOnlyUserOfAnyOperand(); 289 290 static const char *getOpcodeName(unsigned Opcode); 291 292 static inline bool isTerminator(unsigned Opcode) { 293 return Opcode >= TermOpsBegin && Opcode < TermOpsEnd; 294 } 295 296 static inline bool isUnaryOp(unsigned Opcode) { 297 return Opcode >= UnaryOpsBegin && Opcode < UnaryOpsEnd; 298 } 299 static inline bool isBinaryOp(unsigned Opcode) { 300 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd; 301 } 302 303 static inline bool isIntDivRem(unsigned Opcode) { 304 return Opcode == UDiv || Opcode == SDiv || Opcode == URem || Opcode == SRem; 305 } 306 307 /// Determine if the Opcode is one of the shift instructions. 308 static inline bool isShift(unsigned Opcode) { 309 return Opcode >= Shl && Opcode <= AShr; 310 } 311 312 /// Return true if this is a logical shift left or a logical shift right. 313 inline bool isLogicalShift() const { 314 return getOpcode() == Shl || getOpcode() == LShr; 315 } 316 317 /// Return true if this is an arithmetic shift right. 318 inline bool isArithmeticShift() const { 319 return getOpcode() == AShr; 320 } 321 322 /// Determine if the Opcode is and/or/xor. 323 static inline bool isBitwiseLogicOp(unsigned Opcode) { 324 return Opcode == And || Opcode == Or || Opcode == Xor; 325 } 326 327 /// Return true if this is and/or/xor. 328 inline bool isBitwiseLogicOp() const { 329 return isBitwiseLogicOp(getOpcode()); 330 } 331 332 /// Determine if the Opcode is one of the CastInst instructions. 333 static inline bool isCast(unsigned Opcode) { 334 return Opcode >= CastOpsBegin && Opcode < CastOpsEnd; 335 } 336 337 /// Determine if the Opcode is one of the FuncletPadInst instructions. 338 static inline bool isFuncletPad(unsigned Opcode) { 339 return Opcode >= FuncletPadOpsBegin && Opcode < FuncletPadOpsEnd; 340 } 341 342 /// Returns true if the Opcode is a "special" terminator that does more than 343 /// branch to a successor (e.g. have a side effect or return a value). 344 static inline bool isSpecialTerminator(unsigned Opcode) { 345 switch (Opcode) { 346 case Instruction::CatchSwitch: 347 case Instruction::CatchRet: 348 case Instruction::CleanupRet: 349 case Instruction::Invoke: 350 case Instruction::Resume: 351 case Instruction::CallBr: 352 return true; 353 default: 354 return false; 355 } 356 } 357 358 //===--------------------------------------------------------------------===// 359 // Metadata manipulation. 360 //===--------------------------------------------------------------------===// 361 362 /// Return true if this instruction has any metadata attached to it. 363 bool hasMetadata() const { return DbgLoc || Value::hasMetadata(); } 364 365 /// Return true if this instruction has metadata attached to it other than a 366 /// debug location. 367 bool hasMetadataOtherThanDebugLoc() const { return Value::hasMetadata(); } 368 369 /// Return true if this instruction has the given type of metadata attached. 370 bool hasMetadata(unsigned KindID) const { 371 return getMetadata(KindID) != nullptr; 372 } 373 374 /// Return true if this instruction has the given type of metadata attached. 375 bool hasMetadata(StringRef Kind) const { 376 return getMetadata(Kind) != nullptr; 377 } 378 379 /// Get the metadata of given kind attached to this Instruction. 380 /// If the metadata is not found then return null. 381 MDNode *getMetadata(unsigned KindID) const { 382 // Handle 'dbg' as a special case since it is not stored in the hash table. 383 if (KindID == LLVMContext::MD_dbg) 384 return DbgLoc.getAsMDNode(); 385 return Value::getMetadata(KindID); 386 } 387 388 /// Get the metadata of given kind attached to this Instruction. 389 /// If the metadata is not found then return null. 390 MDNode *getMetadata(StringRef Kind) const { 391 if (!hasMetadata()) return nullptr; 392 return getMetadataImpl(Kind); 393 } 394 395 /// Get all metadata attached to this Instruction. The first element of each 396 /// pair returned is the KindID, the second element is the metadata value. 397 /// This list is returned sorted by the KindID. 398 void 399 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 400 if (hasMetadata()) 401 getAllMetadataImpl(MDs); 402 } 403 404 /// This does the same thing as getAllMetadata, except that it filters out the 405 /// debug location. 406 void getAllMetadataOtherThanDebugLoc( 407 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 408 Value::getAllMetadata(MDs); 409 } 410 411 /// Set the metadata of the specified kind to the specified node. This updates 412 /// or replaces metadata if already present, or removes it if Node is null. 413 void setMetadata(unsigned KindID, MDNode *Node); 414 void setMetadata(StringRef Kind, MDNode *Node); 415 416 /// Copy metadata from \p SrcInst to this instruction. \p WL, if not empty, 417 /// specifies the list of meta data that needs to be copied. If \p WL is 418 /// empty, all meta data will be copied. 419 void copyMetadata(const Instruction &SrcInst, 420 ArrayRef<unsigned> WL = ArrayRef<unsigned>()); 421 422 /// Erase all metadata that matches the predicate. 423 void eraseMetadataIf(function_ref<bool(unsigned, MDNode *)> Pred); 424 425 /// If the instruction has "branch_weights" MD_prof metadata and the MDNode 426 /// has three operands (including name string), swap the order of the 427 /// metadata. 428 void swapProfMetadata(); 429 430 /// Drop all unknown metadata except for debug locations. 431 /// @{ 432 /// Passes are required to drop metadata they don't understand. This is a 433 /// convenience method for passes to do so. 434 /// dropUBImplyingAttrsAndUnknownMetadata should be used instead of 435 /// this API if the Instruction being modified is a call. 436 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs = std::nullopt); 437 /// @} 438 439 /// Adds an !annotation metadata node with \p Annotation to this instruction. 440 /// If this instruction already has !annotation metadata, append \p Annotation 441 /// to the existing node. 442 void addAnnotationMetadata(StringRef Annotation); 443 /// Adds an !annotation metadata node with an array of \p Annotations 444 /// as a tuple to this instruction. If this instruction already has 445 /// !annotation metadata, append the tuple to 446 /// the existing node. 447 void addAnnotationMetadata(SmallVector<StringRef> Annotations); 448 /// Returns the AA metadata for this instruction. 449 AAMDNodes getAAMetadata() const; 450 451 /// Sets the AA metadata on this instruction from the AAMDNodes structure. 452 void setAAMetadata(const AAMDNodes &N); 453 454 /// Sets the nosanitize metadata on this instruction. 455 void setNoSanitizeMetadata(); 456 457 /// Retrieve total raw weight values of a branch. 458 /// Returns true on success with profile total weights filled in. 459 /// Returns false if no metadata was found. 460 bool extractProfTotalWeight(uint64_t &TotalVal) const; 461 462 /// Set the debug location information for this instruction. 463 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); } 464 465 /// Return the debug location for this node as a DebugLoc. 466 const DebugLoc &getDebugLoc() const { return DbgLoc; } 467 468 /// Fetch the debug location for this node, unless this is a debug intrinsic, 469 /// in which case fetch the debug location of the next non-debug node. 470 const DebugLoc &getStableDebugLoc() const; 471 472 /// Set or clear the nuw flag on this instruction, which must be an operator 473 /// which supports this flag. See LangRef.html for the meaning of this flag. 474 void setHasNoUnsignedWrap(bool b = true); 475 476 /// Set or clear the nsw flag on this instruction, which must be an operator 477 /// which supports this flag. See LangRef.html for the meaning of this flag. 478 void setHasNoSignedWrap(bool b = true); 479 480 /// Set or clear the exact flag on this instruction, which must be an operator 481 /// which supports this flag. See LangRef.html for the meaning of this flag. 482 void setIsExact(bool b = true); 483 484 /// Set or clear the nneg flag on this instruction, which must be a zext 485 /// instruction. 486 void setNonNeg(bool b = true); 487 488 /// Determine whether the no unsigned wrap flag is set. 489 bool hasNoUnsignedWrap() const LLVM_READONLY; 490 491 /// Determine whether the no signed wrap flag is set. 492 bool hasNoSignedWrap() const LLVM_READONLY; 493 494 /// Determine whether the the nneg flag is set. 495 bool hasNonNeg() const LLVM_READONLY; 496 497 /// Return true if this operator has flags which may cause this instruction 498 /// to evaluate to poison despite having non-poison inputs. 499 bool hasPoisonGeneratingFlags() const LLVM_READONLY; 500 501 /// Drops flags that may cause this instruction to evaluate to poison despite 502 /// having non-poison inputs. 503 void dropPoisonGeneratingFlags(); 504 505 /// Return true if this instruction has poison-generating metadata. 506 bool hasPoisonGeneratingMetadata() const LLVM_READONLY; 507 508 /// Drops metadata that may generate poison. 509 void dropPoisonGeneratingMetadata(); 510 511 /// Return true if this instruction has poison-generating attribute. 512 bool hasPoisonGeneratingReturnAttributes() const LLVM_READONLY; 513 514 /// Drops return attributes that may generate poison. 515 void dropPoisonGeneratingReturnAttributes(); 516 517 /// Return true if this instruction has poison-generating flags, 518 /// return attributes or metadata. 519 bool hasPoisonGeneratingAnnotations() const { 520 return hasPoisonGeneratingFlags() || 521 hasPoisonGeneratingReturnAttributes() || 522 hasPoisonGeneratingMetadata(); 523 } 524 525 /// Drops flags, return attributes and metadata that may generate poison. 526 void dropPoisonGeneratingAnnotations() { 527 dropPoisonGeneratingFlags(); 528 dropPoisonGeneratingReturnAttributes(); 529 dropPoisonGeneratingMetadata(); 530 } 531 532 /// This function drops non-debug unknown metadata (through 533 /// dropUnknownNonDebugMetadata). For calls, it also drops parameter and 534 /// return attributes that can cause undefined behaviour. Both of these should 535 /// be done by passes which move instructions in IR. 536 void dropUBImplyingAttrsAndUnknownMetadata(ArrayRef<unsigned> KnownIDs = {}); 537 538 /// Drop any attributes or metadata that can cause immediate undefined 539 /// behavior. Retain other attributes/metadata on a best-effort basis. 540 /// This should be used when speculating instructions. 541 void dropUBImplyingAttrsAndMetadata(); 542 543 /// Determine whether the exact flag is set. 544 bool isExact() const LLVM_READONLY; 545 546 /// Set or clear all fast-math-flags on this instruction, which must be an 547 /// operator which supports this flag. See LangRef.html for the meaning of 548 /// this flag. 549 void setFast(bool B); 550 551 /// Set or clear the reassociation flag on this instruction, which must be 552 /// an operator which supports this flag. See LangRef.html for the meaning of 553 /// this flag. 554 void setHasAllowReassoc(bool B); 555 556 /// Set or clear the no-nans flag on this instruction, which must be an 557 /// operator which supports this flag. See LangRef.html for the meaning of 558 /// this flag. 559 void setHasNoNaNs(bool B); 560 561 /// Set or clear the no-infs flag on this instruction, which must be an 562 /// operator which supports this flag. See LangRef.html for the meaning of 563 /// this flag. 564 void setHasNoInfs(bool B); 565 566 /// Set or clear the no-signed-zeros flag on this instruction, which must be 567 /// an operator which supports this flag. See LangRef.html for the meaning of 568 /// this flag. 569 void setHasNoSignedZeros(bool B); 570 571 /// Set or clear the allow-reciprocal flag on this instruction, which must be 572 /// an operator which supports this flag. See LangRef.html for the meaning of 573 /// this flag. 574 void setHasAllowReciprocal(bool B); 575 576 /// Set or clear the allow-contract flag on this instruction, which must be 577 /// an operator which supports this flag. See LangRef.html for the meaning of 578 /// this flag. 579 void setHasAllowContract(bool B); 580 581 /// Set or clear the approximate-math-functions flag on this instruction, 582 /// which must be an operator which supports this flag. See LangRef.html for 583 /// the meaning of this flag. 584 void setHasApproxFunc(bool B); 585 586 /// Convenience function for setting multiple fast-math flags on this 587 /// instruction, which must be an operator which supports these flags. See 588 /// LangRef.html for the meaning of these flags. 589 void setFastMathFlags(FastMathFlags FMF); 590 591 /// Convenience function for transferring all fast-math flag values to this 592 /// instruction, which must be an operator which supports these flags. See 593 /// LangRef.html for the meaning of these flags. 594 void copyFastMathFlags(FastMathFlags FMF); 595 596 /// Determine whether all fast-math-flags are set. 597 bool isFast() const LLVM_READONLY; 598 599 /// Determine whether the allow-reassociation flag is set. 600 bool hasAllowReassoc() const LLVM_READONLY; 601 602 /// Determine whether the no-NaNs flag is set. 603 bool hasNoNaNs() const LLVM_READONLY; 604 605 /// Determine whether the no-infs flag is set. 606 bool hasNoInfs() const LLVM_READONLY; 607 608 /// Determine whether the no-signed-zeros flag is set. 609 bool hasNoSignedZeros() const LLVM_READONLY; 610 611 /// Determine whether the allow-reciprocal flag is set. 612 bool hasAllowReciprocal() const LLVM_READONLY; 613 614 /// Determine whether the allow-contract flag is set. 615 bool hasAllowContract() const LLVM_READONLY; 616 617 /// Determine whether the approximate-math-functions flag is set. 618 bool hasApproxFunc() const LLVM_READONLY; 619 620 /// Convenience function for getting all the fast-math flags, which must be an 621 /// operator which supports these flags. See LangRef.html for the meaning of 622 /// these flags. 623 FastMathFlags getFastMathFlags() const LLVM_READONLY; 624 625 /// Copy I's fast-math flags 626 void copyFastMathFlags(const Instruction *I); 627 628 /// Convenience method to copy supported exact, fast-math, and (optionally) 629 /// wrapping flags from V to this instruction. 630 void copyIRFlags(const Value *V, bool IncludeWrapFlags = true); 631 632 /// Logical 'and' of any supported wrapping, exact, and fast-math flags of 633 /// V and this instruction. 634 void andIRFlags(const Value *V); 635 636 /// Merge 2 debug locations and apply it to the Instruction. If the 637 /// instruction is a CallIns, we need to traverse the inline chain to find 638 /// the common scope. This is not efficient for N-way merging as each time 639 /// you merge 2 iterations, you need to rebuild the hashmap to find the 640 /// common scope. However, we still choose this API because: 641 /// 1) Simplicity: it takes 2 locations instead of a list of locations. 642 /// 2) In worst case, it increases the complexity from O(N*I) to 643 /// O(2*N*I), where N is # of Instructions to merge, and I is the 644 /// maximum level of inline stack. So it is still linear. 645 /// 3) Merging of call instructions should be extremely rare in real 646 /// applications, thus the N-way merging should be in code path. 647 /// The DebugLoc attached to this instruction will be overwritten by the 648 /// merged DebugLoc. 649 void applyMergedLocation(DILocation *LocA, DILocation *LocB); 650 651 /// Updates the debug location given that the instruction has been hoisted 652 /// from a block to a predecessor of that block. 653 /// Note: it is undefined behavior to call this on an instruction not 654 /// currently inserted into a function. 655 void updateLocationAfterHoist(); 656 657 /// Drop the instruction's debug location. This does not guarantee removal 658 /// of the !dbg source location attachment, as it must set a line 0 location 659 /// with scope information attached on call instructions. To guarantee 660 /// removal of the !dbg attachment, use the \ref setDebugLoc() API. 661 /// Note: it is undefined behavior to call this on an instruction not 662 /// currently inserted into a function. 663 void dropLocation(); 664 665 /// Merge the DIAssignID metadata from this instruction and those attached to 666 /// instructions in \p SourceInstructions. This process performs a RAUW on 667 /// the MetadataAsValue uses of the merged DIAssignID nodes. Not every 668 /// instruction in \p SourceInstructions needs to have DIAssignID 669 /// metadata. If none of them do then nothing happens. If this instruction 670 /// does not have a DIAssignID attachment but at least one in \p 671 /// SourceInstructions does then the merged one will be attached to 672 /// it. However, instructions without attachments in \p SourceInstructions 673 /// are not modified. 674 void mergeDIAssignID(ArrayRef<const Instruction *> SourceInstructions); 675 676 private: 677 // These are all implemented in Metadata.cpp. 678 MDNode *getMetadataImpl(StringRef Kind) const; 679 void 680 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; 681 682 /// Update the LLVMContext ID-to-Instruction(s) mapping. If \p ID is nullptr 683 /// then clear the mapping for this instruction. 684 void updateDIAssignIDMapping(DIAssignID *ID); 685 686 public: 687 //===--------------------------------------------------------------------===// 688 // Predicates and helper methods. 689 //===--------------------------------------------------------------------===// 690 691 /// Return true if the instruction is associative: 692 /// 693 /// Associative operators satisfy: x op (y op z) === (x op y) op z 694 /// 695 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative. 696 /// 697 bool isAssociative() const LLVM_READONLY; 698 static bool isAssociative(unsigned Opcode) { 699 return Opcode == And || Opcode == Or || Opcode == Xor || 700 Opcode == Add || Opcode == Mul; 701 } 702 703 /// Return true if the instruction is commutative: 704 /// 705 /// Commutative operators satisfy: (x op y) === (y op x) 706 /// 707 /// In LLVM, these are the commutative operators, plus SetEQ and SetNE, when 708 /// applied to any type. 709 /// 710 bool isCommutative() const LLVM_READONLY; 711 static bool isCommutative(unsigned Opcode) { 712 switch (Opcode) { 713 case Add: case FAdd: 714 case Mul: case FMul: 715 case And: case Or: case Xor: 716 return true; 717 default: 718 return false; 719 } 720 } 721 722 /// Return true if the instruction is idempotent: 723 /// 724 /// Idempotent operators satisfy: x op x === x 725 /// 726 /// In LLVM, the And and Or operators are idempotent. 727 /// 728 bool isIdempotent() const { return isIdempotent(getOpcode()); } 729 static bool isIdempotent(unsigned Opcode) { 730 return Opcode == And || Opcode == Or; 731 } 732 733 /// Return true if the instruction is nilpotent: 734 /// 735 /// Nilpotent operators satisfy: x op x === Id, 736 /// 737 /// where Id is the identity for the operator, i.e. a constant such that 738 /// x op Id === x and Id op x === x for all x. 739 /// 740 /// In LLVM, the Xor operator is nilpotent. 741 /// 742 bool isNilpotent() const { return isNilpotent(getOpcode()); } 743 static bool isNilpotent(unsigned Opcode) { 744 return Opcode == Xor; 745 } 746 747 /// Return true if this instruction may modify memory. 748 bool mayWriteToMemory() const LLVM_READONLY; 749 750 /// Return true if this instruction may read memory. 751 bool mayReadFromMemory() const LLVM_READONLY; 752 753 /// Return true if this instruction may read or write memory. 754 bool mayReadOrWriteMemory() const { 755 return mayReadFromMemory() || mayWriteToMemory(); 756 } 757 758 /// Return true if this instruction has an AtomicOrdering of unordered or 759 /// higher. 760 bool isAtomic() const LLVM_READONLY; 761 762 /// Return true if this atomic instruction loads from memory. 763 bool hasAtomicLoad() const LLVM_READONLY; 764 765 /// Return true if this atomic instruction stores to memory. 766 bool hasAtomicStore() const LLVM_READONLY; 767 768 /// Return true if this instruction has a volatile memory access. 769 bool isVolatile() const LLVM_READONLY; 770 771 /// Return the type this instruction accesses in memory, if any. 772 Type *getAccessType() const LLVM_READONLY; 773 774 /// Return true if this instruction may throw an exception. 775 /// 776 /// If IncludePhaseOneUnwind is set, this will also include cases where 777 /// phase one unwinding may unwind past this frame due to skipping of 778 /// cleanup landingpads. 779 bool mayThrow(bool IncludePhaseOneUnwind = false) const LLVM_READONLY; 780 781 /// Return true if this instruction behaves like a memory fence: it can load 782 /// or store to memory location without being given a memory location. 783 bool isFenceLike() const { 784 switch (getOpcode()) { 785 default: 786 return false; 787 // This list should be kept in sync with the list in mayWriteToMemory for 788 // all opcodes which don't have a memory location. 789 case Instruction::Fence: 790 case Instruction::CatchPad: 791 case Instruction::CatchRet: 792 case Instruction::Call: 793 case Instruction::Invoke: 794 return true; 795 } 796 } 797 798 /// Return true if the instruction may have side effects. 799 /// 800 /// Side effects are: 801 /// * Writing to memory. 802 /// * Unwinding. 803 /// * Not returning (e.g. an infinite loop). 804 /// 805 /// Note that this does not consider malloc and alloca to have side 806 /// effects because the newly allocated memory is completely invisible to 807 /// instructions which don't use the returned value. For cases where this 808 /// matters, isSafeToSpeculativelyExecute may be more appropriate. 809 bool mayHaveSideEffects() const LLVM_READONLY; 810 811 /// Return true if the instruction can be removed if the result is unused. 812 /// 813 /// When constant folding some instructions cannot be removed even if their 814 /// results are unused. Specifically terminator instructions and calls that 815 /// may have side effects cannot be removed without semantically changing the 816 /// generated program. 817 bool isSafeToRemove() const LLVM_READONLY; 818 819 /// Return true if the instruction will return (unwinding is considered as 820 /// a form of returning control flow here). 821 bool willReturn() const LLVM_READONLY; 822 823 /// Return true if the instruction is a variety of EH-block. 824 bool isEHPad() const { 825 switch (getOpcode()) { 826 case Instruction::CatchSwitch: 827 case Instruction::CatchPad: 828 case Instruction::CleanupPad: 829 case Instruction::LandingPad: 830 return true; 831 default: 832 return false; 833 } 834 } 835 836 /// Return true if the instruction is a llvm.lifetime.start or 837 /// llvm.lifetime.end marker. 838 bool isLifetimeStartOrEnd() const LLVM_READONLY; 839 840 /// Return true if the instruction is a llvm.launder.invariant.group or 841 /// llvm.strip.invariant.group. 842 bool isLaunderOrStripInvariantGroup() const LLVM_READONLY; 843 844 /// Return true if the instruction is a DbgInfoIntrinsic or PseudoProbeInst. 845 bool isDebugOrPseudoInst() const LLVM_READONLY; 846 847 /// Return a pointer to the next non-debug instruction in the same basic 848 /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 849 /// operations if \c SkipPseudoOp is true. 850 const Instruction * 851 getNextNonDebugInstruction(bool SkipPseudoOp = false) const; 852 Instruction *getNextNonDebugInstruction(bool SkipPseudoOp = false) { 853 return const_cast<Instruction *>( 854 static_cast<const Instruction *>(this)->getNextNonDebugInstruction( 855 SkipPseudoOp)); 856 } 857 858 /// Return a pointer to the previous non-debug instruction in the same basic 859 /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 860 /// operations if \c SkipPseudoOp is true. 861 const Instruction * 862 getPrevNonDebugInstruction(bool SkipPseudoOp = false) const; 863 Instruction *getPrevNonDebugInstruction(bool SkipPseudoOp = false) { 864 return const_cast<Instruction *>( 865 static_cast<const Instruction *>(this)->getPrevNonDebugInstruction( 866 SkipPseudoOp)); 867 } 868 869 /// Create a copy of 'this' instruction that is identical in all ways except 870 /// the following: 871 /// * The instruction has no parent 872 /// * The instruction has no name 873 /// 874 Instruction *clone() const; 875 876 /// Return true if the specified instruction is exactly identical to the 877 /// current one. This means that all operands match and any extra information 878 /// (e.g. load is volatile) agree. 879 bool isIdenticalTo(const Instruction *I) const LLVM_READONLY; 880 881 /// This is like isIdenticalTo, except that it ignores the 882 /// SubclassOptionalData flags, which may specify conditions under which the 883 /// instruction's result is undefined. 884 bool isIdenticalToWhenDefined(const Instruction *I) const LLVM_READONLY; 885 886 /// When checking for operation equivalence (using isSameOperationAs) it is 887 /// sometimes useful to ignore certain attributes. 888 enum OperationEquivalenceFlags { 889 /// Check for equivalence ignoring load/store alignment. 890 CompareIgnoringAlignment = 1<<0, 891 /// Check for equivalence treating a type and a vector of that type 892 /// as equivalent. 893 CompareUsingScalarTypes = 1<<1 894 }; 895 896 /// This function determines if the specified instruction executes the same 897 /// operation as the current one. This means that the opcodes, type, operand 898 /// types and any other factors affecting the operation must be the same. This 899 /// is similar to isIdenticalTo except the operands themselves don't have to 900 /// be identical. 901 /// @returns true if the specified instruction is the same operation as 902 /// the current one. 903 /// Determine if one instruction is the same operation as another. 904 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const LLVM_READONLY; 905 906 /// This function determines if the speficied instruction has the same 907 /// "special" characteristics as the current one. This means that opcode 908 /// specific details are the same. As a common example, if we are comparing 909 /// loads, then hasSameSpecialState would compare the alignments (among 910 /// other things). 911 /// @returns true if the specific instruction has the same opcde specific 912 /// characteristics as the current one. Determine if one instruction has the 913 /// same state as another. 914 bool hasSameSpecialState(const Instruction *I2, 915 bool IgnoreAlignment = false) const LLVM_READONLY; 916 917 /// Return true if there are any uses of this instruction in blocks other than 918 /// the specified block. Note that PHI nodes are considered to evaluate their 919 /// operands in the corresponding predecessor block. 920 bool isUsedOutsideOfBlock(const BasicBlock *BB) const LLVM_READONLY; 921 922 /// Return the number of successors that this instruction has. The instruction 923 /// must be a terminator. 924 unsigned getNumSuccessors() const LLVM_READONLY; 925 926 /// Return the specified successor. This instruction must be a terminator. 927 BasicBlock *getSuccessor(unsigned Idx) const LLVM_READONLY; 928 929 /// Update the specified successor to point at the provided block. This 930 /// instruction must be a terminator. 931 void setSuccessor(unsigned Idx, BasicBlock *BB); 932 933 /// Replace specified successor OldBB to point at the provided block. 934 /// This instruction must be a terminator. 935 void replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB); 936 937 /// Methods for support type inquiry through isa, cast, and dyn_cast: 938 static bool classof(const Value *V) { 939 return V->getValueID() >= Value::InstructionVal; 940 } 941 942 //---------------------------------------------------------------------- 943 // Exported enumerations. 944 // 945 enum TermOps { // These terminate basic blocks 946 #define FIRST_TERM_INST(N) TermOpsBegin = N, 947 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N, 948 #define LAST_TERM_INST(N) TermOpsEnd = N+1 949 #include "llvm/IR/Instruction.def" 950 }; 951 952 enum UnaryOps { 953 #define FIRST_UNARY_INST(N) UnaryOpsBegin = N, 954 #define HANDLE_UNARY_INST(N, OPC, CLASS) OPC = N, 955 #define LAST_UNARY_INST(N) UnaryOpsEnd = N+1 956 #include "llvm/IR/Instruction.def" 957 }; 958 959 enum BinaryOps { 960 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N, 961 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N, 962 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1 963 #include "llvm/IR/Instruction.def" 964 }; 965 966 enum MemoryOps { 967 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N, 968 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N, 969 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1 970 #include "llvm/IR/Instruction.def" 971 }; 972 973 enum CastOps { 974 #define FIRST_CAST_INST(N) CastOpsBegin = N, 975 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N, 976 #define LAST_CAST_INST(N) CastOpsEnd = N+1 977 #include "llvm/IR/Instruction.def" 978 }; 979 980 enum FuncletPadOps { 981 #define FIRST_FUNCLETPAD_INST(N) FuncletPadOpsBegin = N, 982 #define HANDLE_FUNCLETPAD_INST(N, OPC, CLASS) OPC = N, 983 #define LAST_FUNCLETPAD_INST(N) FuncletPadOpsEnd = N+1 984 #include "llvm/IR/Instruction.def" 985 }; 986 987 enum OtherOps { 988 #define FIRST_OTHER_INST(N) OtherOpsBegin = N, 989 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N, 990 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1 991 #include "llvm/IR/Instruction.def" 992 }; 993 994 private: 995 friend class SymbolTableListTraits<Instruction, ilist_iterator_bits<true>, 996 ilist_parent<BasicBlock>>; 997 friend class BasicBlock; // For renumbering. 998 999 // Shadow Value::setValueSubclassData with a private forwarding method so that 1000 // subclasses cannot accidentally use it. 1001 void setValueSubclassData(unsigned short D) { 1002 Value::setValueSubclassData(D); 1003 } 1004 1005 unsigned short getSubclassDataFromValue() const { 1006 return Value::getSubclassDataFromValue(); 1007 } 1008 1009 protected: 1010 // Instruction subclasses can stick up to 15 bits of stuff into the 1011 // SubclassData field of instruction with these members. 1012 1013 template <typename BitfieldElement> 1014 typename BitfieldElement::Type getSubclassData() const { 1015 static_assert( 1016 std::is_same<BitfieldElement, HasMetadataField>::value || 1017 !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 1018 "Must not overlap with the metadata bit"); 1019 return Bitfield::get<BitfieldElement>(getSubclassDataFromValue()); 1020 } 1021 1022 template <typename BitfieldElement> 1023 void setSubclassData(typename BitfieldElement::Type Value) { 1024 static_assert( 1025 std::is_same<BitfieldElement, HasMetadataField>::value || 1026 !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 1027 "Must not overlap with the metadata bit"); 1028 auto Storage = getSubclassDataFromValue(); 1029 Bitfield::set<BitfieldElement>(Storage, Value); 1030 setValueSubclassData(Storage); 1031 } 1032 1033 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 1034 InsertPosition InsertBefore = nullptr); 1035 1036 private: 1037 /// Create a copy of this instruction. 1038 Instruction *cloneImpl() const; 1039 }; 1040 1041 inline void ilist_alloc_traits<Instruction>::deleteNode(Instruction *V) { 1042 V->deleteValue(); 1043 } 1044 1045 } // end namespace llvm 1046 1047 #endif // LLVM_IR_INSTRUCTION_H 1048