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 DPMarker; 33 class FastMathFlags; 34 class MDNode; 35 class Module; 36 struct AAMDNodes; 37 class DPMarker; 38 39 template <> struct ilist_alloc_traits<Instruction> { 40 static inline void deleteNode(Instruction *V); 41 }; 42 43 class Instruction : public User, 44 public ilist_node_with_parent<Instruction, BasicBlock, 45 ilist_iterator_bits<true>> { 46 public: 47 using InstListType = SymbolTableList<Instruction, ilist_iterator_bits<true>>; 48 private: 49 BasicBlock *Parent; 50 DebugLoc DbgLoc; // 'dbg' Metadata cache. 51 52 /// Relative order of this instruction in its parent basic block. Used for 53 /// O(1) local dominance checks between instructions. 54 mutable unsigned Order = 0; 55 56 public: 57 /// Optional marker recording the position for debugging information that 58 /// takes effect immediately before this instruction. Null unless there is 59 /// debugging information present. 60 DPMarker *DbgMarker = nullptr; 61 62 /// Clone any debug-info attached to \p From onto this instruction. Used to 63 /// copy debugging information from one block to another, when copying entire 64 /// blocks. \see DebugProgramInstruction.h , because the ordering of DPValues 65 /// is still important, fine grain control of which instructions are moved and 66 /// where they go is necessary. 67 /// \p From The instruction to clone debug-info from. 68 /// \p from_here Optional iterator to limit DPValues cloned to be a range from 69 /// from_here to end(). 70 /// \p InsertAtHead Whether the cloned DPValues should be placed at the end 71 /// or the beginning of existing DPValues attached to this. 72 /// \returns A range over the newly cloned DPValues. 73 iterator_range<simple_ilist<DPValue>::iterator> cloneDebugInfoFrom( 74 const Instruction *From, 75 std::optional<simple_ilist<DPValue>::iterator> FromHere = std::nullopt, 76 bool InsertAtHead = false); 77 78 /// Return a range over the DPValues attached to this instruction. 79 iterator_range<simple_ilist<DPValue>::iterator> getDbgValueRange() const; 80 81 /// Return an iterator to the position of the "Next" DPValue after this 82 /// instruction, or std::nullopt. This is the position to pass to 83 /// BasicBlock::reinsertInstInDPValues when re-inserting an instruction. 84 std::optional<simple_ilist<DPValue>::iterator> getDbgReinsertionPosition(); 85 86 /// Returns true if any DPValues are attached to this instruction. 87 bool hasDbgValues() const; 88 89 /// Erase any DPValues attached to this instruction. 90 void dropDbgValues(); 91 92 /// Erase a single DPValue \p I that is attached to this instruction. 93 void dropOneDbgValue(DPValue *I); 94 95 /// Handle the debug-info implications of this instruction being removed. Any 96 /// attached DPValues need to "fall" down onto the next instruction. 97 void handleMarkerRemoval(); 98 99 protected: 100 // The 15 first bits of `Value::SubclassData` are available for subclasses of 101 // `Instruction` to use. 102 using OpaqueField = Bitfield::Element<uint16_t, 0, 15>; 103 104 // Template alias so that all Instruction storing alignment use the same 105 // definiton. 106 // Valid alignments are powers of two from 2^0 to 2^MaxAlignmentExponent = 107 // 2^32. We store them as Log2(Alignment), so we need 6 bits to encode the 33 108 // possible values. 109 template <unsigned Offset> 110 using AlignmentBitfieldElementT = 111 typename Bitfield::Element<unsigned, Offset, 6, 112 Value::MaxAlignmentExponent>; 113 114 template <unsigned Offset> 115 using BoolBitfieldElementT = typename Bitfield::Element<bool, Offset, 1>; 116 117 template <unsigned Offset> 118 using AtomicOrderingBitfieldElementT = 119 typename Bitfield::Element<AtomicOrdering, Offset, 3, 120 AtomicOrdering::LAST>; 121 122 private: 123 // The last bit is used to store whether the instruction has metadata attached 124 // or not. 125 using HasMetadataField = Bitfield::Element<bool, 15, 1>; 126 127 protected: 128 ~Instruction(); // Use deleteValue() to delete a generic Instruction. 129 130 public: 131 Instruction(const Instruction &) = delete; 132 Instruction &operator=(const Instruction &) = delete; 133 134 /// Specialize the methods defined in Value, as we know that an instruction 135 /// can only be used by other instructions. 136 Instruction *user_back() { return cast<Instruction>(*user_begin());} 137 const Instruction *user_back() const { return cast<Instruction>(*user_begin());} 138 139 inline const BasicBlock *getParent() const { return Parent; } 140 inline BasicBlock *getParent() { return Parent; } 141 142 /// Return the module owning the function this instruction belongs to 143 /// or nullptr it the function does not have a module. 144 /// 145 /// Note: this is undefined behavior if the instruction does not have a 146 /// parent, or the parent basic block does not have a parent function. 147 const Module *getModule() const; 148 Module *getModule() { 149 return const_cast<Module *>( 150 static_cast<const Instruction *>(this)->getModule()); 151 } 152 153 /// Return the function this instruction belongs to. 154 /// 155 /// Note: it is undefined behavior to call this on an instruction not 156 /// currently inserted into a function. 157 const Function *getFunction() const; 158 Function *getFunction() { 159 return const_cast<Function *>( 160 static_cast<const Instruction *>(this)->getFunction()); 161 } 162 163 /// This method unlinks 'this' from the containing basic block, but does not 164 /// delete it. 165 void removeFromParent(); 166 167 /// This method unlinks 'this' from the containing basic block and deletes it. 168 /// 169 /// \returns an iterator pointing to the element after the erased one 170 InstListType::iterator eraseFromParent(); 171 172 /// Insert an unlinked instruction into a basic block immediately before 173 /// the specified instruction. 174 void insertBefore(Instruction *InsertPos); 175 void insertBefore(InstListType::iterator InsertPos); 176 177 /// Insert an unlinked instruction into a basic block immediately after the 178 /// specified instruction. 179 void insertAfter(Instruction *InsertPos); 180 181 /// Inserts an unlinked instruction into \p ParentBB at position \p It and 182 /// returns the iterator of the inserted instruction. 183 InstListType::iterator insertInto(BasicBlock *ParentBB, 184 InstListType::iterator It); 185 186 void insertBefore(BasicBlock &BB, InstListType::iterator InsertPos); 187 188 /// Unlink this instruction from its current basic block and insert it into 189 /// the basic block that MovePos lives in, right before MovePos. 190 void moveBefore(Instruction *MovePos); 191 192 /// Perform a \ref moveBefore operation, while signalling that the caller 193 /// intends to preserve the original ordering of instructions. This implicitly 194 /// means that any adjacent debug-info should move with this instruction. 195 /// This method is currently a no-op placeholder, but it will become meaningful 196 /// when the "RemoveDIs" project is enabled. 197 void moveBeforePreserving(Instruction *MovePos); 198 199 private: 200 /// RemoveDIs project: all other moves implemented with this method, 201 /// centralising debug-info updates into one place. 202 void moveBeforeImpl(BasicBlock &BB, InstListType::iterator I, bool Preserve); 203 204 public: 205 /// Unlink this instruction and insert into BB before I. 206 /// 207 /// \pre I is a valid iterator into BB. 208 void moveBefore(BasicBlock &BB, InstListType::iterator I); 209 210 /// (See other overload for moveBeforePreserving). 211 void moveBeforePreserving(BasicBlock &BB, InstListType::iterator I); 212 213 /// Unlink this instruction from its current basic block and insert it into 214 /// the basic block that MovePos lives in, right after MovePos. 215 void moveAfter(Instruction *MovePos); 216 217 /// See \ref moveBeforePreserving . 218 void moveAfterPreserving(Instruction *MovePos); 219 220 /// Given an instruction Other in the same basic block as this instruction, 221 /// return true if this instruction comes before Other. In this worst case, 222 /// this takes linear time in the number of instructions in the block. The 223 /// results are cached, so in common cases when the block remains unmodified, 224 /// it takes constant time. 225 bool comesBefore(const Instruction *Other) const; 226 227 /// Get the first insertion point at which the result of this instruction 228 /// is defined. This is *not* the directly following instruction in a number 229 /// of cases, e.g. phi nodes or terminators that return values. This function 230 /// may return null if the insertion after the definition is not possible, 231 /// e.g. due to a catchswitch terminator. 232 std::optional<InstListType::iterator> getInsertionPointAfterDef(); 233 234 //===--------------------------------------------------------------------===// 235 // Subclass classification. 236 //===--------------------------------------------------------------------===// 237 238 /// Returns a member of one of the enums like Instruction::Add. 239 unsigned getOpcode() const { return getValueID() - InstructionVal; } 240 241 const char *getOpcodeName() const { return getOpcodeName(getOpcode()); } 242 bool isTerminator() const { return isTerminator(getOpcode()); } 243 bool isUnaryOp() const { return isUnaryOp(getOpcode()); } 244 bool isBinaryOp() const { return isBinaryOp(getOpcode()); } 245 bool isIntDivRem() const { return isIntDivRem(getOpcode()); } 246 bool isShift() const { return isShift(getOpcode()); } 247 bool isCast() const { return isCast(getOpcode()); } 248 bool isFuncletPad() const { return isFuncletPad(getOpcode()); } 249 bool isSpecialTerminator() const { return isSpecialTerminator(getOpcode()); } 250 251 /// It checks if this instruction is the only user of at least one of 252 /// its operands. 253 bool isOnlyUserOfAnyOperand(); 254 255 static const char *getOpcodeName(unsigned Opcode); 256 257 static inline bool isTerminator(unsigned Opcode) { 258 return Opcode >= TermOpsBegin && Opcode < TermOpsEnd; 259 } 260 261 static inline bool isUnaryOp(unsigned Opcode) { 262 return Opcode >= UnaryOpsBegin && Opcode < UnaryOpsEnd; 263 } 264 static inline bool isBinaryOp(unsigned Opcode) { 265 return Opcode >= BinaryOpsBegin && Opcode < BinaryOpsEnd; 266 } 267 268 static inline bool isIntDivRem(unsigned Opcode) { 269 return Opcode == UDiv || Opcode == SDiv || Opcode == URem || Opcode == SRem; 270 } 271 272 /// Determine if the Opcode is one of the shift instructions. 273 static inline bool isShift(unsigned Opcode) { 274 return Opcode >= Shl && Opcode <= AShr; 275 } 276 277 /// Return true if this is a logical shift left or a logical shift right. 278 inline bool isLogicalShift() const { 279 return getOpcode() == Shl || getOpcode() == LShr; 280 } 281 282 /// Return true if this is an arithmetic shift right. 283 inline bool isArithmeticShift() const { 284 return getOpcode() == AShr; 285 } 286 287 /// Determine if the Opcode is and/or/xor. 288 static inline bool isBitwiseLogicOp(unsigned Opcode) { 289 return Opcode == And || Opcode == Or || Opcode == Xor; 290 } 291 292 /// Return true if this is and/or/xor. 293 inline bool isBitwiseLogicOp() const { 294 return isBitwiseLogicOp(getOpcode()); 295 } 296 297 /// Determine if the Opcode is one of the CastInst instructions. 298 static inline bool isCast(unsigned Opcode) { 299 return Opcode >= CastOpsBegin && Opcode < CastOpsEnd; 300 } 301 302 /// Determine if the Opcode is one of the FuncletPadInst instructions. 303 static inline bool isFuncletPad(unsigned Opcode) { 304 return Opcode >= FuncletPadOpsBegin && Opcode < FuncletPadOpsEnd; 305 } 306 307 /// Returns true if the Opcode is a "special" terminator that does more than 308 /// branch to a successor (e.g. have a side effect or return a value). 309 static inline bool isSpecialTerminator(unsigned Opcode) { 310 switch (Opcode) { 311 case Instruction::CatchSwitch: 312 case Instruction::CatchRet: 313 case Instruction::CleanupRet: 314 case Instruction::Invoke: 315 case Instruction::Resume: 316 case Instruction::CallBr: 317 return true; 318 default: 319 return false; 320 } 321 } 322 323 //===--------------------------------------------------------------------===// 324 // Metadata manipulation. 325 //===--------------------------------------------------------------------===// 326 327 /// Return true if this instruction has any metadata attached to it. 328 bool hasMetadata() const { return DbgLoc || Value::hasMetadata(); } 329 330 /// Return true if this instruction has metadata attached to it other than a 331 /// debug location. 332 bool hasMetadataOtherThanDebugLoc() const { return Value::hasMetadata(); } 333 334 /// Return true if this instruction has the given type of metadata attached. 335 bool hasMetadata(unsigned KindID) const { 336 return getMetadata(KindID) != nullptr; 337 } 338 339 /// Return true if this instruction has the given type of metadata attached. 340 bool hasMetadata(StringRef Kind) const { 341 return getMetadata(Kind) != nullptr; 342 } 343 344 /// Get the metadata of given kind attached to this Instruction. 345 /// If the metadata is not found then return null. 346 MDNode *getMetadata(unsigned KindID) const { 347 // Handle 'dbg' as a special case since it is not stored in the hash table. 348 if (KindID == LLVMContext::MD_dbg) 349 return DbgLoc.getAsMDNode(); 350 return Value::getMetadata(KindID); 351 } 352 353 /// Get the metadata of given kind attached to this Instruction. 354 /// If the metadata is not found then return null. 355 MDNode *getMetadata(StringRef Kind) const { 356 if (!hasMetadata()) return nullptr; 357 return getMetadataImpl(Kind); 358 } 359 360 /// Get all metadata attached to this Instruction. The first element of each 361 /// pair returned is the KindID, the second element is the metadata value. 362 /// This list is returned sorted by the KindID. 363 void 364 getAllMetadata(SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 365 if (hasMetadata()) 366 getAllMetadataImpl(MDs); 367 } 368 369 /// This does the same thing as getAllMetadata, except that it filters out the 370 /// debug location. 371 void getAllMetadataOtherThanDebugLoc( 372 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const { 373 Value::getAllMetadata(MDs); 374 } 375 376 /// Set the metadata of the specified kind to the specified node. This updates 377 /// or replaces metadata if already present, or removes it if Node is null. 378 void setMetadata(unsigned KindID, MDNode *Node); 379 void setMetadata(StringRef Kind, MDNode *Node); 380 381 /// Copy metadata from \p SrcInst to this instruction. \p WL, if not empty, 382 /// specifies the list of meta data that needs to be copied. If \p WL is 383 /// empty, all meta data will be copied. 384 void copyMetadata(const Instruction &SrcInst, 385 ArrayRef<unsigned> WL = ArrayRef<unsigned>()); 386 387 /// Erase all metadata that matches the predicate. 388 void eraseMetadataIf(function_ref<bool(unsigned, MDNode *)> Pred); 389 390 /// If the instruction has "branch_weights" MD_prof metadata and the MDNode 391 /// has three operands (including name string), swap the order of the 392 /// metadata. 393 void swapProfMetadata(); 394 395 /// Drop all unknown metadata except for debug locations. 396 /// @{ 397 /// Passes are required to drop metadata they don't understand. This is a 398 /// convenience method for passes to do so. 399 /// dropUBImplyingAttrsAndUnknownMetadata should be used instead of 400 /// this API if the Instruction being modified is a call. 401 void dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs); 402 void dropUnknownNonDebugMetadata() { 403 return dropUnknownNonDebugMetadata(std::nullopt); 404 } 405 void dropUnknownNonDebugMetadata(unsigned ID1) { 406 return dropUnknownNonDebugMetadata(ArrayRef(ID1)); 407 } 408 void dropUnknownNonDebugMetadata(unsigned ID1, unsigned ID2) { 409 unsigned IDs[] = {ID1, ID2}; 410 return dropUnknownNonDebugMetadata(IDs); 411 } 412 /// @} 413 414 /// Adds an !annotation metadata node with \p Annotation to this instruction. 415 /// If this instruction already has !annotation metadata, append \p Annotation 416 /// to the existing node. 417 void addAnnotationMetadata(StringRef Annotation); 418 /// Adds an !annotation metadata node with an array of \p Annotations 419 /// as a tuple to this instruction. If this instruction already has 420 /// !annotation metadata, append the tuple to 421 /// the existing node. 422 void addAnnotationMetadata(SmallVector<StringRef> Annotations); 423 /// Returns the AA metadata for this instruction. 424 AAMDNodes getAAMetadata() const; 425 426 /// Sets the AA metadata on this instruction from the AAMDNodes structure. 427 void setAAMetadata(const AAMDNodes &N); 428 429 /// Sets the nosanitize metadata on this instruction. 430 void setNoSanitizeMetadata(); 431 432 /// Retrieve total raw weight values of a branch. 433 /// Returns true on success with profile total weights filled in. 434 /// Returns false if no metadata was found. 435 bool extractProfTotalWeight(uint64_t &TotalVal) const; 436 437 /// Set the debug location information for this instruction. 438 void setDebugLoc(DebugLoc Loc) { DbgLoc = std::move(Loc); } 439 440 /// Return the debug location for this node as a DebugLoc. 441 const DebugLoc &getDebugLoc() const { return DbgLoc; } 442 443 /// Fetch the debug location for this node, unless this is a debug intrinsic, 444 /// in which case fetch the debug location of the next non-debug node. 445 const DebugLoc &getStableDebugLoc() const; 446 447 /// Set or clear the nuw flag on this instruction, which must be an operator 448 /// which supports this flag. See LangRef.html for the meaning of this flag. 449 void setHasNoUnsignedWrap(bool b = true); 450 451 /// Set or clear the nsw flag on this instruction, which must be an operator 452 /// which supports this flag. See LangRef.html for the meaning of this flag. 453 void setHasNoSignedWrap(bool b = true); 454 455 /// Set or clear the exact flag on this instruction, which must be an operator 456 /// which supports this flag. See LangRef.html for the meaning of this flag. 457 void setIsExact(bool b = true); 458 459 /// Set or clear the nneg flag on this instruction, which must be a zext 460 /// instruction. 461 void setNonNeg(bool b = true); 462 463 /// Determine whether the no unsigned wrap flag is set. 464 bool hasNoUnsignedWrap() const LLVM_READONLY; 465 466 /// Determine whether the no signed wrap flag is set. 467 bool hasNoSignedWrap() const LLVM_READONLY; 468 469 /// Determine whether the the nneg flag is set. 470 bool hasNonNeg() const LLVM_READONLY; 471 472 /// Return true if this operator has flags which may cause this instruction 473 /// to evaluate to poison despite having non-poison inputs. 474 bool hasPoisonGeneratingFlags() const LLVM_READONLY; 475 476 /// Drops flags that may cause this instruction to evaluate to poison despite 477 /// having non-poison inputs. 478 void dropPoisonGeneratingFlags(); 479 480 /// Return true if this instruction has poison-generating metadata. 481 bool hasPoisonGeneratingMetadata() const LLVM_READONLY; 482 483 /// Drops metadata that may generate poison. 484 void dropPoisonGeneratingMetadata(); 485 486 /// Return true if this instruction has poison-generating flags or metadata. 487 bool hasPoisonGeneratingFlagsOrMetadata() const { 488 return hasPoisonGeneratingFlags() || hasPoisonGeneratingMetadata(); 489 } 490 491 /// Drops flags and metadata that may generate poison. 492 void dropPoisonGeneratingFlagsAndMetadata() { 493 dropPoisonGeneratingFlags(); 494 dropPoisonGeneratingMetadata(); 495 } 496 497 /// This function drops non-debug unknown metadata (through 498 /// dropUnknownNonDebugMetadata). For calls, it also drops parameter and 499 /// return attributes that can cause undefined behaviour. Both of these should 500 /// be done by passes which move instructions in IR. 501 void dropUBImplyingAttrsAndUnknownMetadata(ArrayRef<unsigned> KnownIDs = {}); 502 503 /// Drop any attributes or metadata that can cause immediate undefined 504 /// behavior. Retain other attributes/metadata on a best-effort basis. 505 /// This should be used when speculating instructions. 506 void dropUBImplyingAttrsAndMetadata(); 507 508 /// Determine whether the exact flag is set. 509 bool isExact() const LLVM_READONLY; 510 511 /// Set or clear all fast-math-flags on this instruction, which must be an 512 /// operator which supports this flag. See LangRef.html for the meaning of 513 /// this flag. 514 void setFast(bool B); 515 516 /// Set or clear the reassociation flag on this instruction, which must be 517 /// an operator which supports this flag. See LangRef.html for the meaning of 518 /// this flag. 519 void setHasAllowReassoc(bool B); 520 521 /// Set or clear the no-nans flag on this instruction, which must be an 522 /// operator which supports this flag. See LangRef.html for the meaning of 523 /// this flag. 524 void setHasNoNaNs(bool B); 525 526 /// Set or clear the no-infs flag on this instruction, which must be an 527 /// operator which supports this flag. See LangRef.html for the meaning of 528 /// this flag. 529 void setHasNoInfs(bool B); 530 531 /// Set or clear the no-signed-zeros flag on this instruction, which must be 532 /// an operator which supports this flag. See LangRef.html for the meaning of 533 /// this flag. 534 void setHasNoSignedZeros(bool B); 535 536 /// Set or clear the allow-reciprocal flag on this instruction, which must be 537 /// an operator which supports this flag. See LangRef.html for the meaning of 538 /// this flag. 539 void setHasAllowReciprocal(bool B); 540 541 /// Set or clear the allow-contract flag on this instruction, which must be 542 /// an operator which supports this flag. See LangRef.html for the meaning of 543 /// this flag. 544 void setHasAllowContract(bool B); 545 546 /// Set or clear the approximate-math-functions flag on this instruction, 547 /// which must be an operator which supports this flag. See LangRef.html for 548 /// the meaning of this flag. 549 void setHasApproxFunc(bool B); 550 551 /// Convenience function for setting multiple fast-math flags on this 552 /// instruction, which must be an operator which supports these flags. See 553 /// LangRef.html for the meaning of these flags. 554 void setFastMathFlags(FastMathFlags FMF); 555 556 /// Convenience function for transferring all fast-math flag values to this 557 /// instruction, which must be an operator which supports these flags. See 558 /// LangRef.html for the meaning of these flags. 559 void copyFastMathFlags(FastMathFlags FMF); 560 561 /// Determine whether all fast-math-flags are set. 562 bool isFast() const LLVM_READONLY; 563 564 /// Determine whether the allow-reassociation flag is set. 565 bool hasAllowReassoc() const LLVM_READONLY; 566 567 /// Determine whether the no-NaNs flag is set. 568 bool hasNoNaNs() const LLVM_READONLY; 569 570 /// Determine whether the no-infs flag is set. 571 bool hasNoInfs() const LLVM_READONLY; 572 573 /// Determine whether the no-signed-zeros flag is set. 574 bool hasNoSignedZeros() const LLVM_READONLY; 575 576 /// Determine whether the allow-reciprocal flag is set. 577 bool hasAllowReciprocal() const LLVM_READONLY; 578 579 /// Determine whether the allow-contract flag is set. 580 bool hasAllowContract() const LLVM_READONLY; 581 582 /// Determine whether the approximate-math-functions flag is set. 583 bool hasApproxFunc() const LLVM_READONLY; 584 585 /// Convenience function for getting all the fast-math flags, which must be an 586 /// operator which supports these flags. See LangRef.html for the meaning of 587 /// these flags. 588 FastMathFlags getFastMathFlags() const LLVM_READONLY; 589 590 /// Copy I's fast-math flags 591 void copyFastMathFlags(const Instruction *I); 592 593 /// Convenience method to copy supported exact, fast-math, and (optionally) 594 /// wrapping flags from V to this instruction. 595 void copyIRFlags(const Value *V, bool IncludeWrapFlags = true); 596 597 /// Logical 'and' of any supported wrapping, exact, and fast-math flags of 598 /// V and this instruction. 599 void andIRFlags(const Value *V); 600 601 /// Merge 2 debug locations and apply it to the Instruction. If the 602 /// instruction is a CallIns, we need to traverse the inline chain to find 603 /// the common scope. This is not efficient for N-way merging as each time 604 /// you merge 2 iterations, you need to rebuild the hashmap to find the 605 /// common scope. However, we still choose this API because: 606 /// 1) Simplicity: it takes 2 locations instead of a list of locations. 607 /// 2) In worst case, it increases the complexity from O(N*I) to 608 /// O(2*N*I), where N is # of Instructions to merge, and I is the 609 /// maximum level of inline stack. So it is still linear. 610 /// 3) Merging of call instructions should be extremely rare in real 611 /// applications, thus the N-way merging should be in code path. 612 /// The DebugLoc attached to this instruction will be overwritten by the 613 /// merged DebugLoc. 614 void applyMergedLocation(DILocation *LocA, DILocation *LocB); 615 616 /// Updates the debug location given that the instruction has been hoisted 617 /// from a block to a predecessor of that block. 618 /// Note: it is undefined behavior to call this on an instruction not 619 /// currently inserted into a function. 620 void updateLocationAfterHoist(); 621 622 /// Drop the instruction's debug location. This does not guarantee removal 623 /// of the !dbg source location attachment, as it must set a line 0 location 624 /// with scope information attached on call instructions. To guarantee 625 /// removal of the !dbg attachment, use the \ref setDebugLoc() API. 626 /// Note: it is undefined behavior to call this on an instruction not 627 /// currently inserted into a function. 628 void dropLocation(); 629 630 /// Merge the DIAssignID metadata from this instruction and those attached to 631 /// instructions in \p SourceInstructions. This process performs a RAUW on 632 /// the MetadataAsValue uses of the merged DIAssignID nodes. Not every 633 /// instruction in \p SourceInstructions needs to have DIAssignID 634 /// metadata. If none of them do then nothing happens. If this instruction 635 /// does not have a DIAssignID attachment but at least one in \p 636 /// SourceInstructions does then the merged one will be attached to 637 /// it. However, instructions without attachments in \p SourceInstructions 638 /// are not modified. 639 void mergeDIAssignID(ArrayRef<const Instruction *> SourceInstructions); 640 641 private: 642 // These are all implemented in Metadata.cpp. 643 MDNode *getMetadataImpl(StringRef Kind) const; 644 void 645 getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned, MDNode *>> &) const; 646 647 /// Update the LLVMContext ID-to-Instruction(s) mapping. If \p ID is nullptr 648 /// then clear the mapping for this instruction. 649 void updateDIAssignIDMapping(DIAssignID *ID); 650 651 public: 652 //===--------------------------------------------------------------------===// 653 // Predicates and helper methods. 654 //===--------------------------------------------------------------------===// 655 656 /// Return true if the instruction is associative: 657 /// 658 /// Associative operators satisfy: x op (y op z) === (x op y) op z 659 /// 660 /// In LLVM, the Add, Mul, And, Or, and Xor operators are associative. 661 /// 662 bool isAssociative() const LLVM_READONLY; 663 static bool isAssociative(unsigned Opcode) { 664 return Opcode == And || Opcode == Or || Opcode == Xor || 665 Opcode == Add || Opcode == Mul; 666 } 667 668 /// Return true if the instruction is commutative: 669 /// 670 /// Commutative operators satisfy: (x op y) === (y op x) 671 /// 672 /// In LLVM, these are the commutative operators, plus SetEQ and SetNE, when 673 /// applied to any type. 674 /// 675 bool isCommutative() const LLVM_READONLY; 676 static bool isCommutative(unsigned Opcode) { 677 switch (Opcode) { 678 case Add: case FAdd: 679 case Mul: case FMul: 680 case And: case Or: case Xor: 681 return true; 682 default: 683 return false; 684 } 685 } 686 687 /// Return true if the instruction is idempotent: 688 /// 689 /// Idempotent operators satisfy: x op x === x 690 /// 691 /// In LLVM, the And and Or operators are idempotent. 692 /// 693 bool isIdempotent() const { return isIdempotent(getOpcode()); } 694 static bool isIdempotent(unsigned Opcode) { 695 return Opcode == And || Opcode == Or; 696 } 697 698 /// Return true if the instruction is nilpotent: 699 /// 700 /// Nilpotent operators satisfy: x op x === Id, 701 /// 702 /// where Id is the identity for the operator, i.e. a constant such that 703 /// x op Id === x and Id op x === x for all x. 704 /// 705 /// In LLVM, the Xor operator is nilpotent. 706 /// 707 bool isNilpotent() const { return isNilpotent(getOpcode()); } 708 static bool isNilpotent(unsigned Opcode) { 709 return Opcode == Xor; 710 } 711 712 /// Return true if this instruction may modify memory. 713 bool mayWriteToMemory() const LLVM_READONLY; 714 715 /// Return true if this instruction may read memory. 716 bool mayReadFromMemory() const LLVM_READONLY; 717 718 /// Return true if this instruction may read or write memory. 719 bool mayReadOrWriteMemory() const { 720 return mayReadFromMemory() || mayWriteToMemory(); 721 } 722 723 /// Return true if this instruction has an AtomicOrdering of unordered or 724 /// higher. 725 bool isAtomic() const LLVM_READONLY; 726 727 /// Return true if this atomic instruction loads from memory. 728 bool hasAtomicLoad() const LLVM_READONLY; 729 730 /// Return true if this atomic instruction stores to memory. 731 bool hasAtomicStore() const LLVM_READONLY; 732 733 /// Return true if this instruction has a volatile memory access. 734 bool isVolatile() const LLVM_READONLY; 735 736 /// Return the type this instruction accesses in memory, if any. 737 Type *getAccessType() const LLVM_READONLY; 738 739 /// Return true if this instruction may throw an exception. 740 /// 741 /// If IncludePhaseOneUnwind is set, this will also include cases where 742 /// phase one unwinding may unwind past this frame due to skipping of 743 /// cleanup landingpads. 744 bool mayThrow(bool IncludePhaseOneUnwind = false) const LLVM_READONLY; 745 746 /// Return true if this instruction behaves like a memory fence: it can load 747 /// or store to memory location without being given a memory location. 748 bool isFenceLike() const { 749 switch (getOpcode()) { 750 default: 751 return false; 752 // This list should be kept in sync with the list in mayWriteToMemory for 753 // all opcodes which don't have a memory location. 754 case Instruction::Fence: 755 case Instruction::CatchPad: 756 case Instruction::CatchRet: 757 case Instruction::Call: 758 case Instruction::Invoke: 759 return true; 760 } 761 } 762 763 /// Return true if the instruction may have side effects. 764 /// 765 /// Side effects are: 766 /// * Writing to memory. 767 /// * Unwinding. 768 /// * Not returning (e.g. an infinite loop). 769 /// 770 /// Note that this does not consider malloc and alloca to have side 771 /// effects because the newly allocated memory is completely invisible to 772 /// instructions which don't use the returned value. For cases where this 773 /// matters, isSafeToSpeculativelyExecute may be more appropriate. 774 bool mayHaveSideEffects() const LLVM_READONLY; 775 776 /// Return true if the instruction can be removed if the result is unused. 777 /// 778 /// When constant folding some instructions cannot be removed even if their 779 /// results are unused. Specifically terminator instructions and calls that 780 /// may have side effects cannot be removed without semantically changing the 781 /// generated program. 782 bool isSafeToRemove() const LLVM_READONLY; 783 784 /// Return true if the instruction will return (unwinding is considered as 785 /// a form of returning control flow here). 786 bool willReturn() const LLVM_READONLY; 787 788 /// Return true if the instruction is a variety of EH-block. 789 bool isEHPad() const { 790 switch (getOpcode()) { 791 case Instruction::CatchSwitch: 792 case Instruction::CatchPad: 793 case Instruction::CleanupPad: 794 case Instruction::LandingPad: 795 return true; 796 default: 797 return false; 798 } 799 } 800 801 /// Return true if the instruction is a llvm.lifetime.start or 802 /// llvm.lifetime.end marker. 803 bool isLifetimeStartOrEnd() const LLVM_READONLY; 804 805 /// Return true if the instruction is a llvm.launder.invariant.group or 806 /// llvm.strip.invariant.group. 807 bool isLaunderOrStripInvariantGroup() const LLVM_READONLY; 808 809 /// Return true if the instruction is a DbgInfoIntrinsic or PseudoProbeInst. 810 bool isDebugOrPseudoInst() const LLVM_READONLY; 811 812 /// Return a pointer to the next non-debug instruction in the same basic 813 /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 814 /// operations if \c SkipPseudoOp is true. 815 const Instruction * 816 getNextNonDebugInstruction(bool SkipPseudoOp = false) const; 817 Instruction *getNextNonDebugInstruction(bool SkipPseudoOp = false) { 818 return const_cast<Instruction *>( 819 static_cast<const Instruction *>(this)->getNextNonDebugInstruction( 820 SkipPseudoOp)); 821 } 822 823 /// Return a pointer to the previous non-debug instruction in the same basic 824 /// block as 'this', or nullptr if no such instruction exists. Skip any pseudo 825 /// operations if \c SkipPseudoOp is true. 826 const Instruction * 827 getPrevNonDebugInstruction(bool SkipPseudoOp = false) const; 828 Instruction *getPrevNonDebugInstruction(bool SkipPseudoOp = false) { 829 return const_cast<Instruction *>( 830 static_cast<const Instruction *>(this)->getPrevNonDebugInstruction( 831 SkipPseudoOp)); 832 } 833 834 /// Create a copy of 'this' instruction that is identical in all ways except 835 /// the following: 836 /// * The instruction has no parent 837 /// * The instruction has no name 838 /// 839 Instruction *clone() const; 840 841 /// Return true if the specified instruction is exactly identical to the 842 /// current one. This means that all operands match and any extra information 843 /// (e.g. load is volatile) agree. 844 bool isIdenticalTo(const Instruction *I) const LLVM_READONLY; 845 846 /// This is like isIdenticalTo, except that it ignores the 847 /// SubclassOptionalData flags, which may specify conditions under which the 848 /// instruction's result is undefined. 849 bool isIdenticalToWhenDefined(const Instruction *I) const LLVM_READONLY; 850 851 /// When checking for operation equivalence (using isSameOperationAs) it is 852 /// sometimes useful to ignore certain attributes. 853 enum OperationEquivalenceFlags { 854 /// Check for equivalence ignoring load/store alignment. 855 CompareIgnoringAlignment = 1<<0, 856 /// Check for equivalence treating a type and a vector of that type 857 /// as equivalent. 858 CompareUsingScalarTypes = 1<<1 859 }; 860 861 /// This function determines if the specified instruction executes the same 862 /// operation as the current one. This means that the opcodes, type, operand 863 /// types and any other factors affecting the operation must be the same. This 864 /// is similar to isIdenticalTo except the operands themselves don't have to 865 /// be identical. 866 /// @returns true if the specified instruction is the same operation as 867 /// the current one. 868 /// Determine if one instruction is the same operation as another. 869 bool isSameOperationAs(const Instruction *I, unsigned flags = 0) const LLVM_READONLY; 870 871 /// This function determines if the speficied instruction has the same 872 /// "special" characteristics as the current one. This means that opcode 873 /// specific details are the same. As a common example, if we are comparing 874 /// loads, then hasSameSpecialState would compare the alignments (among 875 /// other things). 876 /// @returns true if the specific instruction has the same opcde specific 877 /// characteristics as the current one. Determine if one instruction has the 878 /// same state as another. 879 bool hasSameSpecialState(const Instruction *I2, 880 bool IgnoreAlignment = false) const LLVM_READONLY; 881 882 /// Return true if there are any uses of this instruction in blocks other than 883 /// the specified block. Note that PHI nodes are considered to evaluate their 884 /// operands in the corresponding predecessor block. 885 bool isUsedOutsideOfBlock(const BasicBlock *BB) const LLVM_READONLY; 886 887 /// Return the number of successors that this instruction has. The instruction 888 /// must be a terminator. 889 unsigned getNumSuccessors() const LLVM_READONLY; 890 891 /// Return the specified successor. This instruction must be a terminator. 892 BasicBlock *getSuccessor(unsigned Idx) const LLVM_READONLY; 893 894 /// Update the specified successor to point at the provided block. This 895 /// instruction must be a terminator. 896 void setSuccessor(unsigned Idx, BasicBlock *BB); 897 898 /// Replace specified successor OldBB to point at the provided block. 899 /// This instruction must be a terminator. 900 void replaceSuccessorWith(BasicBlock *OldBB, BasicBlock *NewBB); 901 902 /// Methods for support type inquiry through isa, cast, and dyn_cast: 903 static bool classof(const Value *V) { 904 return V->getValueID() >= Value::InstructionVal; 905 } 906 907 //---------------------------------------------------------------------- 908 // Exported enumerations. 909 // 910 enum TermOps { // These terminate basic blocks 911 #define FIRST_TERM_INST(N) TermOpsBegin = N, 912 #define HANDLE_TERM_INST(N, OPC, CLASS) OPC = N, 913 #define LAST_TERM_INST(N) TermOpsEnd = N+1 914 #include "llvm/IR/Instruction.def" 915 }; 916 917 enum UnaryOps { 918 #define FIRST_UNARY_INST(N) UnaryOpsBegin = N, 919 #define HANDLE_UNARY_INST(N, OPC, CLASS) OPC = N, 920 #define LAST_UNARY_INST(N) UnaryOpsEnd = N+1 921 #include "llvm/IR/Instruction.def" 922 }; 923 924 enum BinaryOps { 925 #define FIRST_BINARY_INST(N) BinaryOpsBegin = N, 926 #define HANDLE_BINARY_INST(N, OPC, CLASS) OPC = N, 927 #define LAST_BINARY_INST(N) BinaryOpsEnd = N+1 928 #include "llvm/IR/Instruction.def" 929 }; 930 931 enum MemoryOps { 932 #define FIRST_MEMORY_INST(N) MemoryOpsBegin = N, 933 #define HANDLE_MEMORY_INST(N, OPC, CLASS) OPC = N, 934 #define LAST_MEMORY_INST(N) MemoryOpsEnd = N+1 935 #include "llvm/IR/Instruction.def" 936 }; 937 938 enum CastOps { 939 #define FIRST_CAST_INST(N) CastOpsBegin = N, 940 #define HANDLE_CAST_INST(N, OPC, CLASS) OPC = N, 941 #define LAST_CAST_INST(N) CastOpsEnd = N+1 942 #include "llvm/IR/Instruction.def" 943 }; 944 945 enum FuncletPadOps { 946 #define FIRST_FUNCLETPAD_INST(N) FuncletPadOpsBegin = N, 947 #define HANDLE_FUNCLETPAD_INST(N, OPC, CLASS) OPC = N, 948 #define LAST_FUNCLETPAD_INST(N) FuncletPadOpsEnd = N+1 949 #include "llvm/IR/Instruction.def" 950 }; 951 952 enum OtherOps { 953 #define FIRST_OTHER_INST(N) OtherOpsBegin = N, 954 #define HANDLE_OTHER_INST(N, OPC, CLASS) OPC = N, 955 #define LAST_OTHER_INST(N) OtherOpsEnd = N+1 956 #include "llvm/IR/Instruction.def" 957 }; 958 959 private: 960 friend class SymbolTableListTraits<Instruction, ilist_iterator_bits<true>>; 961 friend class BasicBlock; // For renumbering. 962 963 // Shadow Value::setValueSubclassData with a private forwarding method so that 964 // subclasses cannot accidentally use it. 965 void setValueSubclassData(unsigned short D) { 966 Value::setValueSubclassData(D); 967 } 968 969 unsigned short getSubclassDataFromValue() const { 970 return Value::getSubclassDataFromValue(); 971 } 972 973 void setParent(BasicBlock *P); 974 975 protected: 976 // Instruction subclasses can stick up to 15 bits of stuff into the 977 // SubclassData field of instruction with these members. 978 979 template <typename BitfieldElement> 980 typename BitfieldElement::Type getSubclassData() const { 981 static_assert( 982 std::is_same<BitfieldElement, HasMetadataField>::value || 983 !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 984 "Must not overlap with the metadata bit"); 985 return Bitfield::get<BitfieldElement>(getSubclassDataFromValue()); 986 } 987 988 template <typename BitfieldElement> 989 void setSubclassData(typename BitfieldElement::Type Value) { 990 static_assert( 991 std::is_same<BitfieldElement, HasMetadataField>::value || 992 !Bitfield::isOverlapping<BitfieldElement, HasMetadataField>(), 993 "Must not overlap with the metadata bit"); 994 auto Storage = getSubclassDataFromValue(); 995 Bitfield::set<BitfieldElement>(Storage, Value); 996 setValueSubclassData(Storage); 997 } 998 999 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 1000 Instruction *InsertBefore = nullptr); 1001 Instruction(Type *Ty, unsigned iType, Use *Ops, unsigned NumOps, 1002 BasicBlock *InsertAtEnd); 1003 1004 private: 1005 /// Create a copy of this instruction. 1006 Instruction *cloneImpl() const; 1007 }; 1008 1009 inline void ilist_alloc_traits<Instruction>::deleteNode(Instruction *V) { 1010 V->deleteValue(); 1011 } 1012 1013 } // end namespace llvm 1014 1015 #endif // LLVM_IR_INSTRUCTION_H 1016