xref: /llvm-project/llvm/include/llvm/CodeGen/MachineInstr.h (revision f2942b90778670d9ad974d025c779fc96afa737c)
1 //===- llvm/CodeGen/MachineInstr.h - MachineInstr class ---------*- 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 MachineInstr class, which is the
10 // basic representation for all target dependent machine instructions used by
11 // the back end.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CODEGEN_MACHINEINSTR_H
16 #define LLVM_CODEGEN_MACHINEINSTR_H
17 
18 #include "llvm/ADT/DenseMapInfo.h"
19 #include "llvm/ADT/PointerSumType.h"
20 #include "llvm/ADT/ilist.h"
21 #include "llvm/ADT/ilist_node.h"
22 #include "llvm/ADT/iterator_range.h"
23 #include "llvm/Analysis/MemoryLocation.h"
24 #include "llvm/CodeGen/MachineMemOperand.h"
25 #include "llvm/CodeGen/MachineOperand.h"
26 #include "llvm/CodeGen/TargetOpcodes.h"
27 #include "llvm/IR/DebugLoc.h"
28 #include "llvm/IR/InlineAsm.h"
29 #include "llvm/MC/MCInstrDesc.h"
30 #include "llvm/MC/MCSymbol.h"
31 #include "llvm/Support/ArrayRecycler.h"
32 #include "llvm/Support/MathExtras.h"
33 #include "llvm/Support/TrailingObjects.h"
34 #include <algorithm>
35 #include <cassert>
36 #include <cstdint>
37 #include <utility>
38 
39 namespace llvm {
40 
41 class DILabel;
42 class Instruction;
43 class MDNode;
44 class AAResults;
45 class BatchAAResults;
46 template <typename T> class ArrayRef;
47 class DIExpression;
48 class DILocalVariable;
49 class LiveRegUnits;
50 class MachineBasicBlock;
51 class MachineFunction;
52 class MachineRegisterInfo;
53 class ModuleSlotTracker;
54 class raw_ostream;
55 template <typename T> class SmallVectorImpl;
56 class SmallBitVector;
57 class StringRef;
58 class TargetInstrInfo;
59 class TargetRegisterClass;
60 class TargetRegisterInfo;
61 
62 //===----------------------------------------------------------------------===//
63 /// Representation of each machine instruction.
64 ///
65 /// This class isn't a POD type, but it must have a trivial destructor. When a
66 /// MachineFunction is deleted, all the contained MachineInstrs are deallocated
67 /// without having their destructor called.
68 ///
69 class MachineInstr
70     : public ilist_node_with_parent<MachineInstr, MachineBasicBlock,
71                                     ilist_sentinel_tracking<true>> {
72 public:
73   using mmo_iterator = ArrayRef<MachineMemOperand *>::iterator;
74 
75   /// Flags to specify different kinds of comments to output in
76   /// assembly code.  These flags carry semantic information not
77   /// otherwise easily derivable from the IR text.
78   ///
79   enum CommentFlag {
80     ReloadReuse = 0x1,    // higher bits are reserved for target dep comments.
81     NoSchedComment = 0x2,
82     TAsmComments = 0x4    // Target Asm comments should start from this value.
83   };
84 
85   enum MIFlag {
86     NoFlags = 0,
87     FrameSetup = 1 << 0,     // Instruction is used as a part of
88                              // function frame setup code.
89     FrameDestroy = 1 << 1,   // Instruction is used as a part of
90                              // function frame destruction code.
91     BundledPred = 1 << 2,    // Instruction has bundled predecessors.
92     BundledSucc = 1 << 3,    // Instruction has bundled successors.
93     FmNoNans = 1 << 4,       // Instruction does not support Fast
94                              // math nan values.
95     FmNoInfs = 1 << 5,       // Instruction does not support Fast
96                              // math infinity values.
97     FmNsz = 1 << 6,          // Instruction is not required to retain
98                              // signed zero values.
99     FmArcp = 1 << 7,         // Instruction supports Fast math
100                              // reciprocal approximations.
101     FmContract = 1 << 8,     // Instruction supports Fast math
102                              // contraction operations like fma.
103     FmAfn = 1 << 9,          // Instruction may map to Fast math
104                              // intrinsic approximation.
105     FmReassoc = 1 << 10,     // Instruction supports Fast math
106                              // reassociation of operand order.
107     NoUWrap = 1 << 11,       // Instruction supports binary operator
108                              // no unsigned wrap.
109     NoSWrap = 1 << 12,       // Instruction supports binary operator
110                              // no signed wrap.
111     IsExact = 1 << 13,       // Instruction supports division is
112                              // known to be exact.
113     NoFPExcept = 1 << 14,    // Instruction does not raise
114                              // floatint-point exceptions.
115     NoMerge = 1 << 15,       // Passes that drop source location info
116                              // (e.g. branch folding) should skip
117                              // this instruction.
118     Unpredictable = 1 << 16, // Instruction with unpredictable condition.
119     NoConvergent = 1 << 17,  // Call does not require convergence guarantees.
120     NonNeg = 1 << 18,        // The operand is non-negative.
121     Disjoint = 1 << 19,      // Each bit is zero in at least one of the inputs.
122     NoUSWrap = 1 << 20,      // Instruction supports geps
123                              // no unsigned signed wrap.
124     SameSign = 1 << 21       // Both operands have the same sign.
125   };
126 
127 private:
128   const MCInstrDesc *MCID;              // Instruction descriptor.
129   MachineBasicBlock *Parent = nullptr;  // Pointer to the owning basic block.
130 
131   // Operands are allocated by an ArrayRecycler.
132   MachineOperand *Operands = nullptr;   // Pointer to the first operand.
133 
134 #define LLVM_MI_NUMOPERANDS_BITS 24
135 #define LLVM_MI_FLAGS_BITS 24
136 #define LLVM_MI_ASMPRINTERFLAGS_BITS 8
137 
138   /// Number of operands on instruction.
139   uint32_t NumOperands : LLVM_MI_NUMOPERANDS_BITS;
140 
141   // OperandCapacity has uint8_t size, so it should be next to NumOperands
142   // to properly pack.
143   using OperandCapacity = ArrayRecycler<MachineOperand>::Capacity;
144   OperandCapacity CapOperands;          // Capacity of the Operands array.
145 
146   /// Various bits of additional information about the machine instruction.
147   uint32_t Flags : LLVM_MI_FLAGS_BITS;
148 
149   /// Various bits of information used by the AsmPrinter to emit helpful
150   /// comments.  This is *not* semantic information.  Do not use this for
151   /// anything other than to convey comment information to AsmPrinter.
152   uint8_t AsmPrinterFlags : LLVM_MI_ASMPRINTERFLAGS_BITS;
153 
154   /// Internal implementation detail class that provides out-of-line storage for
155   /// extra info used by the machine instruction when this info cannot be stored
156   /// in-line within the instruction itself.
157   ///
158   /// This has to be defined eagerly due to the implementation constraints of
159   /// `PointerSumType` where it is used.
160   class ExtraInfo final : TrailingObjects<ExtraInfo, MachineMemOperand *,
161                                           MCSymbol *, MDNode *, uint32_t> {
162   public:
163     static ExtraInfo *create(BumpPtrAllocator &Allocator,
164                              ArrayRef<MachineMemOperand *> MMOs,
165                              MCSymbol *PreInstrSymbol = nullptr,
166                              MCSymbol *PostInstrSymbol = nullptr,
167                              MDNode *HeapAllocMarker = nullptr,
168                              MDNode *PCSections = nullptr, uint32_t CFIType = 0,
169                              MDNode *MMRAs = nullptr) {
170       bool HasPreInstrSymbol = PreInstrSymbol != nullptr;
171       bool HasPostInstrSymbol = PostInstrSymbol != nullptr;
172       bool HasHeapAllocMarker = HeapAllocMarker != nullptr;
173       bool HasMMRAs = MMRAs != nullptr;
174       bool HasCFIType = CFIType != 0;
175       bool HasPCSections = PCSections != nullptr;
176       auto *Result = new (Allocator.Allocate(
177           totalSizeToAlloc<MachineMemOperand *, MCSymbol *, MDNode *, uint32_t>(
178               MMOs.size(), HasPreInstrSymbol + HasPostInstrSymbol,
179               HasHeapAllocMarker + HasPCSections + HasMMRAs, HasCFIType),
180           alignof(ExtraInfo)))
181           ExtraInfo(MMOs.size(), HasPreInstrSymbol, HasPostInstrSymbol,
182                     HasHeapAllocMarker, HasPCSections, HasCFIType, HasMMRAs);
183 
184       // Copy the actual data into the trailing objects.
185       std::copy(MMOs.begin(), MMOs.end(),
186                 Result->getTrailingObjects<MachineMemOperand *>());
187 
188       unsigned MDNodeIdx = 0;
189 
190       if (HasPreInstrSymbol)
191         Result->getTrailingObjects<MCSymbol *>()[0] = PreInstrSymbol;
192       if (HasPostInstrSymbol)
193         Result->getTrailingObjects<MCSymbol *>()[HasPreInstrSymbol] =
194             PostInstrSymbol;
195       if (HasHeapAllocMarker)
196         Result->getTrailingObjects<MDNode *>()[MDNodeIdx++] = HeapAllocMarker;
197       if (HasPCSections)
198         Result->getTrailingObjects<MDNode *>()[MDNodeIdx++] = PCSections;
199       if (HasCFIType)
200         Result->getTrailingObjects<uint32_t>()[0] = CFIType;
201       if (HasMMRAs)
202         Result->getTrailingObjects<MDNode *>()[MDNodeIdx++] = MMRAs;
203 
204       return Result;
205     }
206 
207     ArrayRef<MachineMemOperand *> getMMOs() const {
208       return ArrayRef(getTrailingObjects<MachineMemOperand *>(), NumMMOs);
209     }
210 
211     MCSymbol *getPreInstrSymbol() const {
212       return HasPreInstrSymbol ? getTrailingObjects<MCSymbol *>()[0] : nullptr;
213     }
214 
215     MCSymbol *getPostInstrSymbol() const {
216       return HasPostInstrSymbol
217                  ? getTrailingObjects<MCSymbol *>()[HasPreInstrSymbol]
218                  : nullptr;
219     }
220 
221     MDNode *getHeapAllocMarker() const {
222       return HasHeapAllocMarker ? getTrailingObjects<MDNode *>()[0] : nullptr;
223     }
224 
225     MDNode *getPCSections() const {
226       return HasPCSections
227                  ? getTrailingObjects<MDNode *>()[HasHeapAllocMarker]
228                  : nullptr;
229     }
230 
231     uint32_t getCFIType() const {
232       return HasCFIType ? getTrailingObjects<uint32_t>()[0] : 0;
233     }
234 
235     MDNode *getMMRAMetadata() const {
236       return HasMMRAs ? getTrailingObjects<MDNode *>()[HasHeapAllocMarker +
237                                                        HasPCSections]
238                       : nullptr;
239     }
240 
241   private:
242     friend TrailingObjects;
243 
244     // Description of the extra info, used to interpret the actual optional
245     // data appended.
246     //
247     // Note that this is not terribly space optimized. This leaves a great deal
248     // of flexibility to fit more in here later.
249     const int NumMMOs;
250     const bool HasPreInstrSymbol;
251     const bool HasPostInstrSymbol;
252     const bool HasHeapAllocMarker;
253     const bool HasPCSections;
254     const bool HasCFIType;
255     const bool HasMMRAs;
256 
257     // Implement the `TrailingObjects` internal API.
258     size_t numTrailingObjects(OverloadToken<MachineMemOperand *>) const {
259       return NumMMOs;
260     }
261     size_t numTrailingObjects(OverloadToken<MCSymbol *>) const {
262       return HasPreInstrSymbol + HasPostInstrSymbol;
263     }
264     size_t numTrailingObjects(OverloadToken<MDNode *>) const {
265       return HasHeapAllocMarker + HasPCSections;
266     }
267     size_t numTrailingObjects(OverloadToken<uint32_t>) const {
268       return HasCFIType;
269     }
270 
271     // Just a boring constructor to allow us to initialize the sizes. Always use
272     // the `create` routine above.
273     ExtraInfo(int NumMMOs, bool HasPreInstrSymbol, bool HasPostInstrSymbol,
274               bool HasHeapAllocMarker, bool HasPCSections, bool HasCFIType,
275               bool HasMMRAs)
276         : NumMMOs(NumMMOs), HasPreInstrSymbol(HasPreInstrSymbol),
277           HasPostInstrSymbol(HasPostInstrSymbol),
278           HasHeapAllocMarker(HasHeapAllocMarker), HasPCSections(HasPCSections),
279           HasCFIType(HasCFIType), HasMMRAs(HasMMRAs) {}
280   };
281 
282   /// Enumeration of the kinds of inline extra info available. It is important
283   /// that the `MachineMemOperand` inline kind has a tag value of zero to make
284   /// it accessible as an `ArrayRef`.
285   enum ExtraInfoInlineKinds {
286     EIIK_MMO = 0,
287     EIIK_PreInstrSymbol,
288     EIIK_PostInstrSymbol,
289     EIIK_OutOfLine
290   };
291 
292   // We store extra information about the instruction here. The common case is
293   // expected to be nothing or a single pointer (typically a MMO or a symbol).
294   // We work to optimize this common case by storing it inline here rather than
295   // requiring a separate allocation, but we fall back to an allocation when
296   // multiple pointers are needed.
297   PointerSumType<ExtraInfoInlineKinds,
298                  PointerSumTypeMember<EIIK_MMO, MachineMemOperand *>,
299                  PointerSumTypeMember<EIIK_PreInstrSymbol, MCSymbol *>,
300                  PointerSumTypeMember<EIIK_PostInstrSymbol, MCSymbol *>,
301                  PointerSumTypeMember<EIIK_OutOfLine, ExtraInfo *>>
302       Info;
303 
304   DebugLoc DbgLoc; // Source line information.
305 
306   /// Unique instruction number. Used by DBG_INSTR_REFs to refer to the values
307   /// defined by this instruction.
308   unsigned DebugInstrNum;
309 
310   /// Cached opcode from MCID.
311   uint16_t Opcode;
312 
313   // Intrusive list support
314   friend struct ilist_traits<MachineInstr>;
315   friend struct ilist_callback_traits<MachineBasicBlock>;
316   void setParent(MachineBasicBlock *P) { Parent = P; }
317 
318   /// This constructor creates a copy of the given
319   /// MachineInstr in the given MachineFunction.
320   MachineInstr(MachineFunction &, const MachineInstr &);
321 
322   /// This constructor create a MachineInstr and add the implicit operands.
323   /// It reserves space for number of operands specified by
324   /// MCInstrDesc.  An explicit DebugLoc is supplied.
325   MachineInstr(MachineFunction &, const MCInstrDesc &TID, DebugLoc DL,
326                bool NoImp = false);
327 
328   // MachineInstrs are pool-allocated and owned by MachineFunction.
329   friend class MachineFunction;
330 
331   void
332   dumprImpl(const MachineRegisterInfo &MRI, unsigned Depth, unsigned MaxDepth,
333             SmallPtrSetImpl<const MachineInstr *> &AlreadySeenInstrs) const;
334 
335   static bool opIsRegDef(const MachineOperand &Op) {
336     return Op.isReg() && Op.isDef();
337   }
338 
339   static bool opIsRegUse(const MachineOperand &Op) {
340     return Op.isReg() && Op.isUse();
341   }
342 
343 public:
344   MachineInstr(const MachineInstr &) = delete;
345   MachineInstr &operator=(const MachineInstr &) = delete;
346   // Use MachineFunction::DeleteMachineInstr() instead.
347   ~MachineInstr() = delete;
348 
349   const MachineBasicBlock* getParent() const { return Parent; }
350   MachineBasicBlock* getParent() { return Parent; }
351 
352   /// Move the instruction before \p MovePos.
353   void moveBefore(MachineInstr *MovePos);
354 
355   /// Return the function that contains the basic block that this instruction
356   /// belongs to.
357   ///
358   /// Note: this is undefined behaviour if the instruction does not have a
359   /// parent.
360   const MachineFunction *getMF() const;
361   MachineFunction *getMF() {
362     return const_cast<MachineFunction *>(
363         static_cast<const MachineInstr *>(this)->getMF());
364   }
365 
366   /// Return the asm printer flags bitvector.
367   uint8_t getAsmPrinterFlags() const { return AsmPrinterFlags; }
368 
369   /// Clear the AsmPrinter bitvector.
370   void clearAsmPrinterFlags() { AsmPrinterFlags = 0; }
371 
372   /// Return whether an AsmPrinter flag is set.
373   bool getAsmPrinterFlag(CommentFlag Flag) const {
374     assert(isUInt<LLVM_MI_ASMPRINTERFLAGS_BITS>(unsigned(Flag)) &&
375            "Flag is out of range for the AsmPrinterFlags field");
376     return AsmPrinterFlags & Flag;
377   }
378 
379   /// Set a flag for the AsmPrinter.
380   void setAsmPrinterFlag(uint8_t Flag) {
381     assert(isUInt<LLVM_MI_ASMPRINTERFLAGS_BITS>(unsigned(Flag)) &&
382            "Flag is out of range for the AsmPrinterFlags field");
383     AsmPrinterFlags |= Flag;
384   }
385 
386   /// Clear specific AsmPrinter flags.
387   void clearAsmPrinterFlag(CommentFlag Flag) {
388     assert(isUInt<LLVM_MI_ASMPRINTERFLAGS_BITS>(unsigned(Flag)) &&
389            "Flag is out of range for the AsmPrinterFlags field");
390     AsmPrinterFlags &= ~Flag;
391   }
392 
393   /// Return the MI flags bitvector.
394   uint32_t getFlags() const {
395     return Flags;
396   }
397 
398   /// Return whether an MI flag is set.
399   bool getFlag(MIFlag Flag) const {
400     assert(isUInt<LLVM_MI_FLAGS_BITS>(unsigned(Flag)) &&
401            "Flag is out of range for the Flags field");
402     return Flags & Flag;
403   }
404 
405   /// Set a MI flag.
406   void setFlag(MIFlag Flag) {
407     assert(isUInt<LLVM_MI_FLAGS_BITS>(unsigned(Flag)) &&
408            "Flag is out of range for the Flags field");
409     Flags |= (uint32_t)Flag;
410   }
411 
412   void setFlags(unsigned flags) {
413     assert(isUInt<LLVM_MI_FLAGS_BITS>(flags) &&
414            "flags to be set are out of range for the Flags field");
415     // Filter out the automatically maintained flags.
416     unsigned Mask = BundledPred | BundledSucc;
417     Flags = (Flags & Mask) | (flags & ~Mask);
418   }
419 
420   /// clearFlag - Clear a MI flag.
421   void clearFlag(MIFlag Flag) {
422     assert(isUInt<LLVM_MI_FLAGS_BITS>(unsigned(Flag)) &&
423            "Flag to clear is out of range for the Flags field");
424     Flags &= ~((uint32_t)Flag);
425   }
426 
427   void clearFlags(unsigned flags) {
428     assert(isUInt<LLVM_MI_FLAGS_BITS>(flags) &&
429            "flags to be cleared are out of range for the Flags field");
430     Flags &= ~flags;
431   }
432 
433   /// Return true if MI is in a bundle (but not the first MI in a bundle).
434   ///
435   /// A bundle looks like this before it's finalized:
436   ///   ----------------
437   ///   |      MI      |
438   ///   ----------------
439   ///          |
440   ///   ----------------
441   ///   |      MI    * |
442   ///   ----------------
443   ///          |
444   ///   ----------------
445   ///   |      MI    * |
446   ///   ----------------
447   /// In this case, the first MI starts a bundle but is not inside a bundle, the
448   /// next 2 MIs are considered "inside" the bundle.
449   ///
450   /// After a bundle is finalized, it looks like this:
451   ///   ----------------
452   ///   |    Bundle    |
453   ///   ----------------
454   ///          |
455   ///   ----------------
456   ///   |      MI    * |
457   ///   ----------------
458   ///          |
459   ///   ----------------
460   ///   |      MI    * |
461   ///   ----------------
462   ///          |
463   ///   ----------------
464   ///   |      MI    * |
465   ///   ----------------
466   /// The first instruction has the special opcode "BUNDLE". It's not "inside"
467   /// a bundle, but the next three MIs are.
468   bool isInsideBundle() const {
469     return getFlag(BundledPred);
470   }
471 
472   /// Return true if this instruction part of a bundle. This is true
473   /// if either itself or its following instruction is marked "InsideBundle".
474   bool isBundled() const {
475     return isBundledWithPred() || isBundledWithSucc();
476   }
477 
478   /// Return true if this instruction is part of a bundle, and it is not the
479   /// first instruction in the bundle.
480   bool isBundledWithPred() const { return getFlag(BundledPred); }
481 
482   /// Return true if this instruction is part of a bundle, and it is not the
483   /// last instruction in the bundle.
484   bool isBundledWithSucc() const { return getFlag(BundledSucc); }
485 
486   /// Bundle this instruction with its predecessor. This can be an unbundled
487   /// instruction, or it can be the first instruction in a bundle.
488   void bundleWithPred();
489 
490   /// Bundle this instruction with its successor. This can be an unbundled
491   /// instruction, or it can be the last instruction in a bundle.
492   void bundleWithSucc();
493 
494   /// Break bundle above this instruction.
495   void unbundleFromPred();
496 
497   /// Break bundle below this instruction.
498   void unbundleFromSucc();
499 
500   /// Returns the debug location id of this MachineInstr.
501   const DebugLoc &getDebugLoc() const { return DbgLoc; }
502 
503   /// Return the operand containing the offset to be used if this DBG_VALUE
504   /// instruction is indirect; will be an invalid register if this value is
505   /// not indirect, and an immediate with value 0 otherwise.
506   const MachineOperand &getDebugOffset() const {
507     assert(isNonListDebugValue() && "not a DBG_VALUE");
508     return getOperand(1);
509   }
510   MachineOperand &getDebugOffset() {
511     assert(isNonListDebugValue() && "not a DBG_VALUE");
512     return getOperand(1);
513   }
514 
515   /// Return the operand for the debug variable referenced by
516   /// this DBG_VALUE instruction.
517   const MachineOperand &getDebugVariableOp() const;
518   MachineOperand &getDebugVariableOp();
519 
520   /// Return the debug variable referenced by
521   /// this DBG_VALUE instruction.
522   const DILocalVariable *getDebugVariable() const;
523 
524   /// Return the operand for the complex address expression referenced by
525   /// this DBG_VALUE instruction.
526   const MachineOperand &getDebugExpressionOp() const;
527   MachineOperand &getDebugExpressionOp();
528 
529   /// Return the complex address expression referenced by
530   /// this DBG_VALUE instruction.
531   const DIExpression *getDebugExpression() const;
532 
533   /// Return the debug label referenced by
534   /// this DBG_LABEL instruction.
535   const DILabel *getDebugLabel() const;
536 
537   /// Fetch the instruction number of this MachineInstr. If it does not have
538   /// one already, a new and unique number will be assigned.
539   unsigned getDebugInstrNum();
540 
541   /// Fetch instruction number of this MachineInstr -- but before it's inserted
542   /// into \p MF. Needed for transformations that create an instruction but
543   /// don't immediately insert them.
544   unsigned getDebugInstrNum(MachineFunction &MF);
545 
546   /// Examine the instruction number of this MachineInstr. May be zero if
547   /// it hasn't been assigned a number yet.
548   unsigned peekDebugInstrNum() const { return DebugInstrNum; }
549 
550   /// Set instruction number of this MachineInstr. Avoid using unless you're
551   /// deserializing this information.
552   void setDebugInstrNum(unsigned Num) { DebugInstrNum = Num; }
553 
554   /// Drop any variable location debugging information associated with this
555   /// instruction. Use when an instruction is modified in such a way that it no
556   /// longer defines the value it used to. Variable locations using that value
557   /// will be dropped.
558   void dropDebugNumber() { DebugInstrNum = 0; }
559 
560   /// For inline asm, get the !srcloc metadata node if we have it, and decode
561   /// the loc cookie from it.
562   const MDNode *getLocCookieMD() const;
563 
564   /// Emit an error referring to the source location of this instruction. This
565   /// should only be used for inline assembly that is somehow impossible to
566   /// compile. Other errors should have been handled much earlier.
567   void emitInlineAsmError(const Twine &ErrMsg) const;
568 
569   // Emit an error in the LLVMContext referring to the source location of this
570   // instruction, if available.
571   void emitGenericError(const Twine &ErrMsg) const;
572 
573   /// Returns the target instruction descriptor of this MachineInstr.
574   const MCInstrDesc &getDesc() const { return *MCID; }
575 
576   /// Returns the opcode of this MachineInstr.
577   unsigned getOpcode() const { return Opcode; }
578 
579   /// Retuns the total number of operands.
580   unsigned getNumOperands() const { return NumOperands; }
581 
582   /// Returns the total number of operands which are debug locations.
583   unsigned getNumDebugOperands() const {
584     return std::distance(debug_operands().begin(), debug_operands().end());
585   }
586 
587   const MachineOperand& getOperand(unsigned i) const {
588     assert(i < getNumOperands() && "getOperand() out of range!");
589     return Operands[i];
590   }
591   MachineOperand& getOperand(unsigned i) {
592     assert(i < getNumOperands() && "getOperand() out of range!");
593     return Operands[i];
594   }
595 
596   MachineOperand &getDebugOperand(unsigned Index) {
597     assert(Index < getNumDebugOperands() && "getDebugOperand() out of range!");
598     return *(debug_operands().begin() + Index);
599   }
600   const MachineOperand &getDebugOperand(unsigned Index) const {
601     assert(Index < getNumDebugOperands() && "getDebugOperand() out of range!");
602     return *(debug_operands().begin() + Index);
603   }
604 
605   /// Returns whether this debug value has at least one debug operand with the
606   /// register \p Reg.
607   bool hasDebugOperandForReg(Register Reg) const {
608     return any_of(debug_operands(), [Reg](const MachineOperand &Op) {
609       return Op.isReg() && Op.getReg() == Reg;
610     });
611   }
612 
613   /// Returns a range of all of the operands that correspond to a debug use of
614   /// \p Reg.
615   template <typename Operand, typename Instruction>
616   static iterator_range<
617       filter_iterator<Operand *, std::function<bool(Operand &Op)>>>
618   getDebugOperandsForReg(Instruction *MI, Register Reg) {
619     std::function<bool(Operand & Op)> OpUsesReg(
620         [Reg](Operand &Op) { return Op.isReg() && Op.getReg() == Reg; });
621     return make_filter_range(MI->debug_operands(), OpUsesReg);
622   }
623   iterator_range<filter_iterator<const MachineOperand *,
624                                  std::function<bool(const MachineOperand &Op)>>>
625   getDebugOperandsForReg(Register Reg) const {
626     return MachineInstr::getDebugOperandsForReg<const MachineOperand,
627                                                 const MachineInstr>(this, Reg);
628   }
629   iterator_range<filter_iterator<MachineOperand *,
630                                  std::function<bool(MachineOperand &Op)>>>
631   getDebugOperandsForReg(Register Reg) {
632     return MachineInstr::getDebugOperandsForReg<MachineOperand, MachineInstr>(
633         this, Reg);
634   }
635 
636   bool isDebugOperand(const MachineOperand *Op) const {
637     return Op >= adl_begin(debug_operands()) && Op <= adl_end(debug_operands());
638   }
639 
640   unsigned getDebugOperandIndex(const MachineOperand *Op) const {
641     assert(isDebugOperand(Op) && "Expected a debug operand.");
642     return std::distance(adl_begin(debug_operands()), Op);
643   }
644 
645   /// Returns the total number of definitions.
646   unsigned getNumDefs() const {
647     return getNumExplicitDefs() + MCID->implicit_defs().size();
648   }
649 
650   /// Returns true if the instruction has implicit definition.
651   bool hasImplicitDef() const {
652     for (const MachineOperand &MO : implicit_operands())
653       if (MO.isDef())
654         return true;
655     return false;
656   }
657 
658   /// Returns the implicit operands number.
659   unsigned getNumImplicitOperands() const {
660     return getNumOperands() - getNumExplicitOperands();
661   }
662 
663   /// Return true if operand \p OpIdx is a subregister index.
664   bool isOperandSubregIdx(unsigned OpIdx) const {
665     assert(getOperand(OpIdx).isImm() && "Expected MO_Immediate operand type.");
666     if (isExtractSubreg() && OpIdx == 2)
667       return true;
668     if (isInsertSubreg() && OpIdx == 3)
669       return true;
670     if (isRegSequence() && OpIdx > 1 && (OpIdx % 2) == 0)
671       return true;
672     if (isSubregToReg() && OpIdx == 3)
673       return true;
674     return false;
675   }
676 
677   /// Returns the number of non-implicit operands.
678   unsigned getNumExplicitOperands() const;
679 
680   /// Returns the number of non-implicit definitions.
681   unsigned getNumExplicitDefs() const;
682 
683   /// iterator/begin/end - Iterate over all operands of a machine instruction.
684   using mop_iterator = MachineOperand *;
685   using const_mop_iterator = const MachineOperand *;
686 
687   mop_iterator operands_begin() { return Operands; }
688   mop_iterator operands_end() { return Operands + NumOperands; }
689 
690   const_mop_iterator operands_begin() const { return Operands; }
691   const_mop_iterator operands_end() const { return Operands + NumOperands; }
692 
693   iterator_range<mop_iterator> operands() {
694     return make_range(operands_begin(), operands_end());
695   }
696   iterator_range<const_mop_iterator> operands() const {
697     return make_range(operands_begin(), operands_end());
698   }
699   iterator_range<mop_iterator> explicit_operands() {
700     return make_range(operands_begin(),
701                       operands_begin() + getNumExplicitOperands());
702   }
703   iterator_range<const_mop_iterator> explicit_operands() const {
704     return make_range(operands_begin(),
705                       operands_begin() + getNumExplicitOperands());
706   }
707   iterator_range<mop_iterator> implicit_operands() {
708     return make_range(explicit_operands().end(), operands_end());
709   }
710   iterator_range<const_mop_iterator> implicit_operands() const {
711     return make_range(explicit_operands().end(), operands_end());
712   }
713   /// Returns a range over all operands that are used to determine the variable
714   /// location for this DBG_VALUE instruction.
715   iterator_range<mop_iterator> debug_operands() {
716     assert((isDebugValueLike()) && "Must be a debug value instruction.");
717     return isNonListDebugValue()
718                ? make_range(operands_begin(), operands_begin() + 1)
719                : make_range(operands_begin() + 2, operands_end());
720   }
721   /// \copydoc debug_operands()
722   iterator_range<const_mop_iterator> debug_operands() const {
723     assert((isDebugValueLike()) && "Must be a debug value instruction.");
724     return isNonListDebugValue()
725                ? make_range(operands_begin(), operands_begin() + 1)
726                : make_range(operands_begin() + 2, operands_end());
727   }
728   /// Returns a range over all explicit operands that are register definitions.
729   /// Implicit definition are not included!
730   iterator_range<mop_iterator> defs() {
731     return make_range(operands_begin(),
732                       operands_begin() + getNumExplicitDefs());
733   }
734   /// \copydoc defs()
735   iterator_range<const_mop_iterator> defs() const {
736     return make_range(operands_begin(),
737                       operands_begin() + getNumExplicitDefs());
738   }
739   /// Returns a range that includes all operands which may be register uses.
740   /// This may include unrelated operands which are not register uses.
741   iterator_range<mop_iterator> uses() {
742     return make_range(operands_begin() + getNumExplicitDefs(), operands_end());
743   }
744   /// \copydoc uses()
745   iterator_range<const_mop_iterator> uses() const {
746     return make_range(operands_begin() + getNumExplicitDefs(), operands_end());
747   }
748   iterator_range<mop_iterator> explicit_uses() {
749     return make_range(operands_begin() + getNumExplicitDefs(),
750                       operands_begin() + getNumExplicitOperands());
751   }
752   iterator_range<const_mop_iterator> explicit_uses() const {
753     return make_range(operands_begin() + getNumExplicitDefs(),
754                       operands_begin() + getNumExplicitOperands());
755   }
756 
757   using filtered_mop_iterator =
758       filter_iterator<mop_iterator, bool (*)(const MachineOperand &)>;
759   using filtered_const_mop_iterator =
760       filter_iterator<const_mop_iterator, bool (*)(const MachineOperand &)>;
761 
762   /// Returns an iterator range over all operands that are (explicit or
763   /// implicit) register defs.
764   iterator_range<filtered_mop_iterator> all_defs() {
765     return make_filter_range(operands(), opIsRegDef);
766   }
767   /// \copydoc all_defs()
768   iterator_range<filtered_const_mop_iterator> all_defs() const {
769     return make_filter_range(operands(), opIsRegDef);
770   }
771 
772   /// Returns an iterator range over all operands that are (explicit or
773   /// implicit) register uses.
774   iterator_range<filtered_mop_iterator> all_uses() {
775     return make_filter_range(uses(), opIsRegUse);
776   }
777   /// \copydoc all_uses()
778   iterator_range<filtered_const_mop_iterator> all_uses() const {
779     return make_filter_range(uses(), opIsRegUse);
780   }
781 
782   /// Returns the number of the operand iterator \p I points to.
783   unsigned getOperandNo(const_mop_iterator I) const {
784     return I - operands_begin();
785   }
786 
787   /// Access to memory operands of the instruction. If there are none, that does
788   /// not imply anything about whether the function accesses memory. Instead,
789   /// the caller must behave conservatively.
790   ArrayRef<MachineMemOperand *> memoperands() const {
791     if (!Info)
792       return {};
793 
794     if (Info.is<EIIK_MMO>())
795       return ArrayRef(Info.getAddrOfZeroTagPointer(), 1);
796 
797     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
798       return EI->getMMOs();
799 
800     return {};
801   }
802 
803   /// Access to memory operands of the instruction.
804   ///
805   /// If `memoperands_begin() == memoperands_end()`, that does not imply
806   /// anything about whether the function accesses memory. Instead, the caller
807   /// must behave conservatively.
808   mmo_iterator memoperands_begin() const { return memoperands().begin(); }
809 
810   /// Access to memory operands of the instruction.
811   ///
812   /// If `memoperands_begin() == memoperands_end()`, that does not imply
813   /// anything about whether the function accesses memory. Instead, the caller
814   /// must behave conservatively.
815   mmo_iterator memoperands_end() const { return memoperands().end(); }
816 
817   /// Return true if we don't have any memory operands which described the
818   /// memory access done by this instruction.  If this is true, calling code
819   /// must be conservative.
820   bool memoperands_empty() const { return memoperands().empty(); }
821 
822   /// Return true if this instruction has exactly one MachineMemOperand.
823   bool hasOneMemOperand() const { return memoperands().size() == 1; }
824 
825   /// Return the number of memory operands.
826   unsigned getNumMemOperands() const { return memoperands().size(); }
827 
828   /// Helper to extract a pre-instruction symbol if one has been added.
829   MCSymbol *getPreInstrSymbol() const {
830     if (!Info)
831       return nullptr;
832     if (MCSymbol *S = Info.get<EIIK_PreInstrSymbol>())
833       return S;
834     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
835       return EI->getPreInstrSymbol();
836 
837     return nullptr;
838   }
839 
840   /// Helper to extract a post-instruction symbol if one has been added.
841   MCSymbol *getPostInstrSymbol() const {
842     if (!Info)
843       return nullptr;
844     if (MCSymbol *S = Info.get<EIIK_PostInstrSymbol>())
845       return S;
846     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
847       return EI->getPostInstrSymbol();
848 
849     return nullptr;
850   }
851 
852   /// Helper to extract a heap alloc marker if one has been added.
853   MDNode *getHeapAllocMarker() const {
854     if (!Info)
855       return nullptr;
856     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
857       return EI->getHeapAllocMarker();
858 
859     return nullptr;
860   }
861 
862   /// Helper to extract PCSections metadata target sections.
863   MDNode *getPCSections() const {
864     if (!Info)
865       return nullptr;
866     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
867       return EI->getPCSections();
868 
869     return nullptr;
870   }
871 
872   /// Helper to extract mmra.op metadata.
873   MDNode *getMMRAMetadata() const {
874     if (!Info)
875       return nullptr;
876     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
877       return EI->getMMRAMetadata();
878     return nullptr;
879   }
880 
881   /// Helper to extract a CFI type hash if one has been added.
882   uint32_t getCFIType() const {
883     if (!Info)
884       return 0;
885     if (ExtraInfo *EI = Info.get<EIIK_OutOfLine>())
886       return EI->getCFIType();
887 
888     return 0;
889   }
890 
891   /// API for querying MachineInstr properties. They are the same as MCInstrDesc
892   /// queries but they are bundle aware.
893 
894   enum QueryType {
895     IgnoreBundle,    // Ignore bundles
896     AnyInBundle,     // Return true if any instruction in bundle has property
897     AllInBundle      // Return true if all instructions in bundle have property
898   };
899 
900   /// Return true if the instruction (or in the case of a bundle,
901   /// the instructions inside the bundle) has the specified property.
902   /// The first argument is the property being queried.
903   /// The second argument indicates whether the query should look inside
904   /// instruction bundles.
905   bool hasProperty(unsigned MCFlag, QueryType Type = AnyInBundle) const {
906     assert(MCFlag < 64 &&
907            "MCFlag out of range for bit mask in getFlags/hasPropertyInBundle.");
908     // Inline the fast path for unbundled or bundle-internal instructions.
909     if (Type == IgnoreBundle || !isBundled() || isBundledWithPred())
910       return getDesc().getFlags() & (1ULL << MCFlag);
911 
912     // If this is the first instruction in a bundle, take the slow path.
913     return hasPropertyInBundle(1ULL << MCFlag, Type);
914   }
915 
916   /// Return true if this is an instruction that should go through the usual
917   /// legalization steps.
918   bool isPreISelOpcode(QueryType Type = IgnoreBundle) const {
919     return hasProperty(MCID::PreISelOpcode, Type);
920   }
921 
922   /// Return true if this instruction can have a variable number of operands.
923   /// In this case, the variable operands will be after the normal
924   /// operands but before the implicit definitions and uses (if any are
925   /// present).
926   bool isVariadic(QueryType Type = IgnoreBundle) const {
927     return hasProperty(MCID::Variadic, Type);
928   }
929 
930   /// Set if this instruction has an optional definition, e.g.
931   /// ARM instructions which can set condition code if 's' bit is set.
932   bool hasOptionalDef(QueryType Type = IgnoreBundle) const {
933     return hasProperty(MCID::HasOptionalDef, Type);
934   }
935 
936   /// Return true if this is a pseudo instruction that doesn't
937   /// correspond to a real machine instruction.
938   bool isPseudo(QueryType Type = IgnoreBundle) const {
939     return hasProperty(MCID::Pseudo, Type);
940   }
941 
942   /// Return true if this instruction doesn't produce any output in the form of
943   /// executable instructions.
944   bool isMetaInstruction(QueryType Type = IgnoreBundle) const {
945     return hasProperty(MCID::Meta, Type);
946   }
947 
948   bool isReturn(QueryType Type = AnyInBundle) const {
949     return hasProperty(MCID::Return, Type);
950   }
951 
952   /// Return true if this is an instruction that marks the end of an EH scope,
953   /// i.e., a catchpad or a cleanuppad instruction.
954   bool isEHScopeReturn(QueryType Type = AnyInBundle) const {
955     return hasProperty(MCID::EHScopeReturn, Type);
956   }
957 
958   bool isCall(QueryType Type = AnyInBundle) const {
959     return hasProperty(MCID::Call, Type);
960   }
961 
962   /// Return true if this is a call instruction that may have an additional
963   /// information associated with it.
964   bool isCandidateForAdditionalCallInfo(QueryType Type = IgnoreBundle) const;
965 
966   /// Return true if copying, moving, or erasing this instruction requires
967   /// updating additional call info (see \ref copyCallInfo, \ref moveCallInfo,
968   /// \ref eraseCallInfo).
969   bool shouldUpdateAdditionalCallInfo() const;
970 
971   /// Returns true if the specified instruction stops control flow
972   /// from executing the instruction immediately following it.  Examples include
973   /// unconditional branches and return instructions.
974   bool isBarrier(QueryType Type = AnyInBundle) const {
975     return hasProperty(MCID::Barrier, Type);
976   }
977 
978   /// Returns true if this instruction part of the terminator for a basic block.
979   /// Typically this is things like return and branch instructions.
980   ///
981   /// Various passes use this to insert code into the bottom of a basic block,
982   /// but before control flow occurs.
983   bool isTerminator(QueryType Type = AnyInBundle) const {
984     return hasProperty(MCID::Terminator, Type);
985   }
986 
987   /// Returns true if this is a conditional, unconditional, or indirect branch.
988   /// Predicates below can be used to discriminate between
989   /// these cases, and the TargetInstrInfo::analyzeBranch method can be used to
990   /// get more information.
991   bool isBranch(QueryType Type = AnyInBundle) const {
992     return hasProperty(MCID::Branch, Type);
993   }
994 
995   /// Return true if this is an indirect branch, such as a
996   /// branch through a register.
997   bool isIndirectBranch(QueryType Type = AnyInBundle) const {
998     return hasProperty(MCID::IndirectBranch, Type);
999   }
1000 
1001   /// Return true if this is a branch which may fall
1002   /// through to the next instruction or may transfer control flow to some other
1003   /// block.  The TargetInstrInfo::analyzeBranch method can be used to get more
1004   /// information about this branch.
1005   bool isConditionalBranch(QueryType Type = AnyInBundle) const {
1006     return isBranch(Type) && !isBarrier(Type) && !isIndirectBranch(Type);
1007   }
1008 
1009   /// Return true if this is a branch which always
1010   /// transfers control flow to some other block.  The
1011   /// TargetInstrInfo::analyzeBranch method can be used to get more information
1012   /// about this branch.
1013   bool isUnconditionalBranch(QueryType Type = AnyInBundle) const {
1014     return isBranch(Type) && isBarrier(Type) && !isIndirectBranch(Type);
1015   }
1016 
1017   /// Return true if this instruction has a predicate operand that
1018   /// controls execution.  It may be set to 'always', or may be set to other
1019   /// values.   There are various methods in TargetInstrInfo that can be used to
1020   /// control and modify the predicate in this instruction.
1021   bool isPredicable(QueryType Type = AllInBundle) const {
1022     // If it's a bundle than all bundled instructions must be predicable for this
1023     // to return true.
1024     return hasProperty(MCID::Predicable, Type);
1025   }
1026 
1027   /// Return true if this instruction is a comparison.
1028   bool isCompare(QueryType Type = IgnoreBundle) const {
1029     return hasProperty(MCID::Compare, Type);
1030   }
1031 
1032   /// Return true if this instruction is a move immediate
1033   /// (including conditional moves) instruction.
1034   bool isMoveImmediate(QueryType Type = IgnoreBundle) const {
1035     return hasProperty(MCID::MoveImm, Type);
1036   }
1037 
1038   /// Return true if this instruction is a register move.
1039   /// (including moving values from subreg to reg)
1040   bool isMoveReg(QueryType Type = IgnoreBundle) const {
1041     return hasProperty(MCID::MoveReg, Type);
1042   }
1043 
1044   /// Return true if this instruction is a bitcast instruction.
1045   bool isBitcast(QueryType Type = IgnoreBundle) const {
1046     return hasProperty(MCID::Bitcast, Type);
1047   }
1048 
1049   /// Return true if this instruction is a select instruction.
1050   bool isSelect(QueryType Type = IgnoreBundle) const {
1051     return hasProperty(MCID::Select, Type);
1052   }
1053 
1054   /// Return true if this instruction cannot be safely duplicated.
1055   /// For example, if the instruction has a unique labels attached
1056   /// to it, duplicating it would cause multiple definition errors.
1057   bool isNotDuplicable(QueryType Type = AnyInBundle) const {
1058     if (getPreInstrSymbol() || getPostInstrSymbol())
1059       return true;
1060     return hasProperty(MCID::NotDuplicable, Type);
1061   }
1062 
1063   /// Return true if this instruction is convergent.
1064   /// Convergent instructions can not be made control-dependent on any
1065   /// additional values.
1066   bool isConvergent(QueryType Type = AnyInBundle) const {
1067     if (isInlineAsm()) {
1068       unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1069       if (ExtraInfo & InlineAsm::Extra_IsConvergent)
1070         return true;
1071     }
1072     if (getFlag(NoConvergent))
1073       return false;
1074     return hasProperty(MCID::Convergent, Type);
1075   }
1076 
1077   /// Returns true if the specified instruction has a delay slot
1078   /// which must be filled by the code generator.
1079   bool hasDelaySlot(QueryType Type = AnyInBundle) const {
1080     return hasProperty(MCID::DelaySlot, Type);
1081   }
1082 
1083   /// Return true for instructions that can be folded as
1084   /// memory operands in other instructions. The most common use for this
1085   /// is instructions that are simple loads from memory that don't modify
1086   /// the loaded value in any way, but it can also be used for instructions
1087   /// that can be expressed as constant-pool loads, such as V_SETALLONES
1088   /// on x86, to allow them to be folded when it is beneficial.
1089   /// This should only be set on instructions that return a value in their
1090   /// only virtual register definition.
1091   bool canFoldAsLoad(QueryType Type = IgnoreBundle) const {
1092     return hasProperty(MCID::FoldableAsLoad, Type);
1093   }
1094 
1095   /// Return true if this instruction behaves
1096   /// the same way as the generic REG_SEQUENCE instructions.
1097   /// E.g., on ARM,
1098   /// dX VMOVDRR rY, rZ
1099   /// is equivalent to
1100   /// dX = REG_SEQUENCE rY, ssub_0, rZ, ssub_1.
1101   ///
1102   /// Note that for the optimizers to be able to take advantage of
1103   /// this property, TargetInstrInfo::getRegSequenceLikeInputs has to be
1104   /// override accordingly.
1105   bool isRegSequenceLike(QueryType Type = IgnoreBundle) const {
1106     return hasProperty(MCID::RegSequence, Type);
1107   }
1108 
1109   /// Return true if this instruction behaves
1110   /// the same way as the generic EXTRACT_SUBREG instructions.
1111   /// E.g., on ARM,
1112   /// rX, rY VMOVRRD dZ
1113   /// is equivalent to two EXTRACT_SUBREG:
1114   /// rX = EXTRACT_SUBREG dZ, ssub_0
1115   /// rY = EXTRACT_SUBREG dZ, ssub_1
1116   ///
1117   /// Note that for the optimizers to be able to take advantage of
1118   /// this property, TargetInstrInfo::getExtractSubregLikeInputs has to be
1119   /// override accordingly.
1120   bool isExtractSubregLike(QueryType Type = IgnoreBundle) const {
1121     return hasProperty(MCID::ExtractSubreg, Type);
1122   }
1123 
1124   /// Return true if this instruction behaves
1125   /// the same way as the generic INSERT_SUBREG instructions.
1126   /// E.g., on ARM,
1127   /// dX = VSETLNi32 dY, rZ, Imm
1128   /// is equivalent to a INSERT_SUBREG:
1129   /// dX = INSERT_SUBREG dY, rZ, translateImmToSubIdx(Imm)
1130   ///
1131   /// Note that for the optimizers to be able to take advantage of
1132   /// this property, TargetInstrInfo::getInsertSubregLikeInputs has to be
1133   /// override accordingly.
1134   bool isInsertSubregLike(QueryType Type = IgnoreBundle) const {
1135     return hasProperty(MCID::InsertSubreg, Type);
1136   }
1137 
1138   //===--------------------------------------------------------------------===//
1139   // Side Effect Analysis
1140   //===--------------------------------------------------------------------===//
1141 
1142   /// Return true if this instruction could possibly read memory.
1143   /// Instructions with this flag set are not necessarily simple load
1144   /// instructions, they may load a value and modify it, for example.
1145   bool mayLoad(QueryType Type = AnyInBundle) const {
1146     if (isInlineAsm()) {
1147       unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1148       if (ExtraInfo & InlineAsm::Extra_MayLoad)
1149         return true;
1150     }
1151     return hasProperty(MCID::MayLoad, Type);
1152   }
1153 
1154   /// Return true if this instruction could possibly modify memory.
1155   /// Instructions with this flag set are not necessarily simple store
1156   /// instructions, they may store a modified value based on their operands, or
1157   /// may not actually modify anything, for example.
1158   bool mayStore(QueryType Type = AnyInBundle) const {
1159     if (isInlineAsm()) {
1160       unsigned ExtraInfo = getOperand(InlineAsm::MIOp_ExtraInfo).getImm();
1161       if (ExtraInfo & InlineAsm::Extra_MayStore)
1162         return true;
1163     }
1164     return hasProperty(MCID::MayStore, Type);
1165   }
1166 
1167   /// Return true if this instruction could possibly read or modify memory.
1168   bool mayLoadOrStore(QueryType Type = AnyInBundle) const {
1169     return mayLoad(Type) || mayStore(Type);
1170   }
1171 
1172   /// Return true if this instruction could possibly raise a floating-point
1173   /// exception.  This is the case if the instruction is a floating-point
1174   /// instruction that can in principle raise an exception, as indicated
1175   /// by the MCID::MayRaiseFPException property, *and* at the same time,
1176   /// the instruction is used in a context where we expect floating-point
1177   /// exceptions are not disabled, as indicated by the NoFPExcept MI flag.
1178   bool mayRaiseFPException() const {
1179     return hasProperty(MCID::MayRaiseFPException) &&
1180            !getFlag(MachineInstr::MIFlag::NoFPExcept);
1181   }
1182 
1183   //===--------------------------------------------------------------------===//
1184   // Flags that indicate whether an instruction can be modified by a method.
1185   //===--------------------------------------------------------------------===//
1186 
1187   /// Return true if this may be a 2- or 3-address
1188   /// instruction (of the form "X = op Y, Z, ..."), which produces the same
1189   /// result if Y and Z are exchanged.  If this flag is set, then the
1190   /// TargetInstrInfo::commuteInstruction method may be used to hack on the
1191   /// instruction.
1192   ///
1193   /// Note that this flag may be set on instructions that are only commutable
1194   /// sometimes.  In these cases, the call to commuteInstruction will fail.
1195   /// Also note that some instructions require non-trivial modification to
1196   /// commute them.
1197   bool isCommutable(QueryType Type = IgnoreBundle) const {
1198     return hasProperty(MCID::Commutable, Type);
1199   }
1200 
1201   /// Return true if this is a 2-address instruction
1202   /// which can be changed into a 3-address instruction if needed.  Doing this
1203   /// transformation can be profitable in the register allocator, because it
1204   /// means that the instruction can use a 2-address form if possible, but
1205   /// degrade into a less efficient form if the source and dest register cannot
1206   /// be assigned to the same register.  For example, this allows the x86
1207   /// backend to turn a "shl reg, 3" instruction into an LEA instruction, which
1208   /// is the same speed as the shift but has bigger code size.
1209   ///
1210   /// If this returns true, then the target must implement the
1211   /// TargetInstrInfo::convertToThreeAddress method for this instruction, which
1212   /// is allowed to fail if the transformation isn't valid for this specific
1213   /// instruction (e.g. shl reg, 4 on x86).
1214   ///
1215   bool isConvertibleTo3Addr(QueryType Type = IgnoreBundle) const {
1216     return hasProperty(MCID::ConvertibleTo3Addr, Type);
1217   }
1218 
1219   /// Return true if this instruction requires
1220   /// custom insertion support when the DAG scheduler is inserting it into a
1221   /// machine basic block.  If this is true for the instruction, it basically
1222   /// means that it is a pseudo instruction used at SelectionDAG time that is
1223   /// expanded out into magic code by the target when MachineInstrs are formed.
1224   ///
1225   /// If this is true, the TargetLoweringInfo::InsertAtEndOfBasicBlock method
1226   /// is used to insert this into the MachineBasicBlock.
1227   bool usesCustomInsertionHook(QueryType Type = IgnoreBundle) const {
1228     return hasProperty(MCID::UsesCustomInserter, Type);
1229   }
1230 
1231   /// Return true if this instruction requires *adjustment*
1232   /// after instruction selection by calling a target hook. For example, this
1233   /// can be used to fill in ARM 's' optional operand depending on whether
1234   /// the conditional flag register is used.
1235   bool hasPostISelHook(QueryType Type = IgnoreBundle) const {
1236     return hasProperty(MCID::HasPostISelHook, Type);
1237   }
1238 
1239   /// Returns true if this instruction is a candidate for remat.
1240   /// This flag is deprecated, please don't use it anymore.  If this
1241   /// flag is set, the isReallyTriviallyReMaterializable() method is called to
1242   /// verify the instruction is really rematerializable.
1243   bool isRematerializable(QueryType Type = AllInBundle) const {
1244     // It's only possible to re-mat a bundle if all bundled instructions are
1245     // re-materializable.
1246     return hasProperty(MCID::Rematerializable, Type);
1247   }
1248 
1249   /// Returns true if this instruction has the same cost (or less) than a move
1250   /// instruction. This is useful during certain types of optimizations
1251   /// (e.g., remat during two-address conversion or machine licm)
1252   /// where we would like to remat or hoist the instruction, but not if it costs
1253   /// more than moving the instruction into the appropriate register. Note, we
1254   /// are not marking copies from and to the same register class with this flag.
1255   bool isAsCheapAsAMove(QueryType Type = AllInBundle) const {
1256     // Only returns true for a bundle if all bundled instructions are cheap.
1257     return hasProperty(MCID::CheapAsAMove, Type);
1258   }
1259 
1260   /// Returns true if this instruction source operands
1261   /// have special register allocation requirements that are not captured by the
1262   /// operand register classes. e.g. ARM::STRD's two source registers must be an
1263   /// even / odd pair, ARM::STM registers have to be in ascending order.
1264   /// Post-register allocation passes should not attempt to change allocations
1265   /// for sources of instructions with this flag.
1266   bool hasExtraSrcRegAllocReq(QueryType Type = AnyInBundle) const {
1267     return hasProperty(MCID::ExtraSrcRegAllocReq, Type);
1268   }
1269 
1270   /// Returns true if this instruction def operands
1271   /// have special register allocation requirements that are not captured by the
1272   /// operand register classes. e.g. ARM::LDRD's two def registers must be an
1273   /// even / odd pair, ARM::LDM registers have to be in ascending order.
1274   /// Post-register allocation passes should not attempt to change allocations
1275   /// for definitions of instructions with this flag.
1276   bool hasExtraDefRegAllocReq(QueryType Type = AnyInBundle) const {
1277     return hasProperty(MCID::ExtraDefRegAllocReq, Type);
1278   }
1279 
1280   enum MICheckType {
1281     CheckDefs,      // Check all operands for equality
1282     CheckKillDead,  // Check all operands including kill / dead markers
1283     IgnoreDefs,     // Ignore all definitions
1284     IgnoreVRegDefs  // Ignore virtual register definitions
1285   };
1286 
1287   /// Return true if this instruction is identical to \p Other.
1288   /// Two instructions are identical if they have the same opcode and all their
1289   /// operands are identical (with respect to MachineOperand::isIdenticalTo()).
1290   /// Note that this means liveness related flags (dead, undef, kill) do not
1291   /// affect the notion of identical.
1292   bool isIdenticalTo(const MachineInstr &Other,
1293                      MICheckType Check = CheckDefs) const;
1294 
1295   /// Returns true if this instruction is a debug instruction that represents an
1296   /// identical debug value to \p Other.
1297   /// This function considers these debug instructions equivalent if they have
1298   /// identical variables, debug locations, and debug operands, and if the
1299   /// DIExpressions combined with the directness flags are equivalent.
1300   bool isEquivalentDbgInstr(const MachineInstr &Other) const;
1301 
1302   /// Unlink 'this' from the containing basic block, and return it without
1303   /// deleting it.
1304   ///
1305   /// This function can not be used on bundled instructions, use
1306   /// removeFromBundle() to remove individual instructions from a bundle.
1307   MachineInstr *removeFromParent();
1308 
1309   /// Unlink this instruction from its basic block and return it without
1310   /// deleting it.
1311   ///
1312   /// If the instruction is part of a bundle, the other instructions in the
1313   /// bundle remain bundled.
1314   MachineInstr *removeFromBundle();
1315 
1316   /// Unlink 'this' from the containing basic block and delete it.
1317   ///
1318   /// If this instruction is the header of a bundle, the whole bundle is erased.
1319   /// This function can not be used for instructions inside a bundle, use
1320   /// eraseFromBundle() to erase individual bundled instructions.
1321   void eraseFromParent();
1322 
1323   /// Unlink 'this' from its basic block and delete it.
1324   ///
1325   /// If the instruction is part of a bundle, the other instructions in the
1326   /// bundle remain bundled.
1327   void eraseFromBundle();
1328 
1329   bool isEHLabel() const { return getOpcode() == TargetOpcode::EH_LABEL; }
1330   bool isGCLabel() const { return getOpcode() == TargetOpcode::GC_LABEL; }
1331   bool isAnnotationLabel() const {
1332     return getOpcode() == TargetOpcode::ANNOTATION_LABEL;
1333   }
1334 
1335   bool isLifetimeMarker() const {
1336     return getOpcode() == TargetOpcode::LIFETIME_START ||
1337            getOpcode() == TargetOpcode::LIFETIME_END;
1338   }
1339 
1340   /// Returns true if the MachineInstr represents a label.
1341   bool isLabel() const {
1342     return isEHLabel() || isGCLabel() || isAnnotationLabel();
1343   }
1344 
1345   bool isCFIInstruction() const {
1346     return getOpcode() == TargetOpcode::CFI_INSTRUCTION;
1347   }
1348 
1349   bool isPseudoProbe() const {
1350     return getOpcode() == TargetOpcode::PSEUDO_PROBE;
1351   }
1352 
1353   // True if the instruction represents a position in the function.
1354   bool isPosition() const { return isLabel() || isCFIInstruction(); }
1355 
1356   bool isNonListDebugValue() const {
1357     return getOpcode() == TargetOpcode::DBG_VALUE;
1358   }
1359   bool isDebugValueList() const {
1360     return getOpcode() == TargetOpcode::DBG_VALUE_LIST;
1361   }
1362   bool isDebugValue() const {
1363     return isNonListDebugValue() || isDebugValueList();
1364   }
1365   bool isDebugLabel() const { return getOpcode() == TargetOpcode::DBG_LABEL; }
1366   bool isDebugRef() const { return getOpcode() == TargetOpcode::DBG_INSTR_REF; }
1367   bool isDebugValueLike() const { return isDebugValue() || isDebugRef(); }
1368   bool isDebugPHI() const { return getOpcode() == TargetOpcode::DBG_PHI; }
1369   bool isDebugInstr() const {
1370     return isDebugValue() || isDebugLabel() || isDebugRef() || isDebugPHI();
1371   }
1372   bool isDebugOrPseudoInstr() const {
1373     return isDebugInstr() || isPseudoProbe();
1374   }
1375 
1376   bool isDebugOffsetImm() const {
1377     return isNonListDebugValue() && getDebugOffset().isImm();
1378   }
1379 
1380   /// A DBG_VALUE is indirect iff the location operand is a register and
1381   /// the offset operand is an immediate.
1382   bool isIndirectDebugValue() const {
1383     return isDebugOffsetImm() && getDebugOperand(0).isReg();
1384   }
1385 
1386   /// A DBG_VALUE is an entry value iff its debug expression contains the
1387   /// DW_OP_LLVM_entry_value operation.
1388   bool isDebugEntryValue() const;
1389 
1390   /// Return true if the instruction is a debug value which describes a part of
1391   /// a variable as unavailable.
1392   bool isUndefDebugValue() const {
1393     if (!isDebugValue())
1394       return false;
1395     // If any $noreg locations are given, this DV is undef.
1396     for (const MachineOperand &Op : debug_operands())
1397       if (Op.isReg() && !Op.getReg().isValid())
1398         return true;
1399     return false;
1400   }
1401 
1402   bool isJumpTableDebugInfo() const {
1403     return getOpcode() == TargetOpcode::JUMP_TABLE_DEBUG_INFO;
1404   }
1405 
1406   bool isPHI() const {
1407     return getOpcode() == TargetOpcode::PHI ||
1408            getOpcode() == TargetOpcode::G_PHI;
1409   }
1410   bool isKill() const { return getOpcode() == TargetOpcode::KILL; }
1411   bool isImplicitDef() const { return getOpcode()==TargetOpcode::IMPLICIT_DEF; }
1412   bool isInlineAsm() const {
1413     return getOpcode() == TargetOpcode::INLINEASM ||
1414            getOpcode() == TargetOpcode::INLINEASM_BR;
1415   }
1416   /// Returns true if the register operand can be folded with a load or store
1417   /// into a frame index. Does so by checking the InlineAsm::Flag immediate
1418   /// operand at OpId - 1.
1419   bool mayFoldInlineAsmRegOp(unsigned OpId) const;
1420 
1421   bool isStackAligningInlineAsm() const;
1422   InlineAsm::AsmDialect getInlineAsmDialect() const;
1423 
1424   bool isInsertSubreg() const {
1425     return getOpcode() == TargetOpcode::INSERT_SUBREG;
1426   }
1427 
1428   bool isSubregToReg() const {
1429     return getOpcode() == TargetOpcode::SUBREG_TO_REG;
1430   }
1431 
1432   bool isRegSequence() const {
1433     return getOpcode() == TargetOpcode::REG_SEQUENCE;
1434   }
1435 
1436   bool isBundle() const {
1437     return getOpcode() == TargetOpcode::BUNDLE;
1438   }
1439 
1440   bool isCopy() const {
1441     return getOpcode() == TargetOpcode::COPY;
1442   }
1443 
1444   bool isFullCopy() const {
1445     return isCopy() && !getOperand(0).getSubReg() && !getOperand(1).getSubReg();
1446   }
1447 
1448   bool isExtractSubreg() const {
1449     return getOpcode() == TargetOpcode::EXTRACT_SUBREG;
1450   }
1451 
1452   bool isFakeUse() const { return getOpcode() == TargetOpcode::FAKE_USE; }
1453 
1454   /// Return true if the instruction behaves like a copy.
1455   /// This does not include native copy instructions.
1456   bool isCopyLike() const {
1457     return isCopy() || isSubregToReg();
1458   }
1459 
1460   /// Return true is the instruction is an identity copy.
1461   bool isIdentityCopy() const {
1462     return isCopy() && getOperand(0).getReg() == getOperand(1).getReg() &&
1463       getOperand(0).getSubReg() == getOperand(1).getSubReg();
1464   }
1465 
1466   /// Return true if this is a transient instruction that is either very likely
1467   /// to be eliminated during register allocation (such as copy-like
1468   /// instructions), or if this instruction doesn't have an execution-time cost.
1469   bool isTransient() const {
1470     switch (getOpcode()) {
1471     default:
1472       return isMetaInstruction();
1473     // Copy-like instructions are usually eliminated during register allocation.
1474     case TargetOpcode::PHI:
1475     case TargetOpcode::G_PHI:
1476     case TargetOpcode::COPY:
1477     case TargetOpcode::INSERT_SUBREG:
1478     case TargetOpcode::SUBREG_TO_REG:
1479     case TargetOpcode::REG_SEQUENCE:
1480       return true;
1481     }
1482   }
1483 
1484   /// Return the number of instructions inside the MI bundle, excluding the
1485   /// bundle header.
1486   ///
1487   /// This is the number of instructions that MachineBasicBlock::iterator
1488   /// skips, 0 for unbundled instructions.
1489   unsigned getBundleSize() const;
1490 
1491   /// Return true if the MachineInstr reads the specified register.
1492   /// If TargetRegisterInfo is non-null, then it also checks if there
1493   /// is a read of a super-register.
1494   /// This does not count partial redefines of virtual registers as reads:
1495   ///   %reg1024:6 = OP.
1496   bool readsRegister(Register Reg, const TargetRegisterInfo *TRI) const {
1497     return findRegisterUseOperandIdx(Reg, TRI, false) != -1;
1498   }
1499 
1500   /// Return true if the MachineInstr reads the specified virtual register.
1501   /// Take into account that a partial define is a
1502   /// read-modify-write operation.
1503   bool readsVirtualRegister(Register Reg) const {
1504     return readsWritesVirtualRegister(Reg).first;
1505   }
1506 
1507   /// Return a pair of bools (reads, writes) indicating if this instruction
1508   /// reads or writes Reg. This also considers partial defines.
1509   /// If Ops is not null, all operand indices for Reg are added.
1510   std::pair<bool,bool> readsWritesVirtualRegister(Register Reg,
1511                                 SmallVectorImpl<unsigned> *Ops = nullptr) const;
1512 
1513   /// Return true if the MachineInstr kills the specified register.
1514   /// If TargetRegisterInfo is non-null, then it also checks if there is
1515   /// a kill of a super-register.
1516   bool killsRegister(Register Reg, const TargetRegisterInfo *TRI) const {
1517     return findRegisterUseOperandIdx(Reg, TRI, true) != -1;
1518   }
1519 
1520   /// Return true if the MachineInstr fully defines the specified register.
1521   /// If TargetRegisterInfo is non-null, then it also checks
1522   /// if there is a def of a super-register.
1523   /// NOTE: It's ignoring subreg indices on virtual registers.
1524   bool definesRegister(Register Reg, const TargetRegisterInfo *TRI) const {
1525     return findRegisterDefOperandIdx(Reg, TRI, false, false) != -1;
1526   }
1527 
1528   /// Return true if the MachineInstr modifies (fully define or partially
1529   /// define) the specified register.
1530   /// NOTE: It's ignoring subreg indices on virtual registers.
1531   bool modifiesRegister(Register Reg, const TargetRegisterInfo *TRI) const {
1532     return findRegisterDefOperandIdx(Reg, TRI, false, true) != -1;
1533   }
1534 
1535   /// Returns true if the register is dead in this machine instruction.
1536   /// If TargetRegisterInfo is non-null, then it also checks
1537   /// if there is a dead def of a super-register.
1538   bool registerDefIsDead(Register Reg, const TargetRegisterInfo *TRI) const {
1539     return findRegisterDefOperandIdx(Reg, TRI, true, false) != -1;
1540   }
1541 
1542   /// Returns true if the MachineInstr has an implicit-use operand of exactly
1543   /// the given register (not considering sub/super-registers).
1544   bool hasRegisterImplicitUseOperand(Register Reg) const;
1545 
1546   /// Returns the operand index that is a use of the specific register or -1
1547   /// if it is not found. It further tightens the search criteria to a use
1548   /// that kills the register if isKill is true.
1549   int findRegisterUseOperandIdx(Register Reg, const TargetRegisterInfo *TRI,
1550                                 bool isKill = false) const;
1551 
1552   /// Wrapper for findRegisterUseOperandIdx, it returns
1553   /// a pointer to the MachineOperand rather than an index.
1554   MachineOperand *findRegisterUseOperand(Register Reg,
1555                                          const TargetRegisterInfo *TRI,
1556                                          bool isKill = false) {
1557     int Idx = findRegisterUseOperandIdx(Reg, TRI, isKill);
1558     return (Idx == -1) ? nullptr : &getOperand(Idx);
1559   }
1560 
1561   const MachineOperand *findRegisterUseOperand(Register Reg,
1562                                                const TargetRegisterInfo *TRI,
1563                                                bool isKill = false) const {
1564     return const_cast<MachineInstr *>(this)->findRegisterUseOperand(Reg, TRI,
1565                                                                     isKill);
1566   }
1567 
1568   /// Returns the operand index that is a def of the specified register or
1569   /// -1 if it is not found. If isDead is true, defs that are not dead are
1570   /// skipped. If Overlap is true, then it also looks for defs that merely
1571   /// overlap the specified register. If TargetRegisterInfo is non-null,
1572   /// then it also checks if there is a def of a super-register.
1573   /// This may also return a register mask operand when Overlap is true.
1574   int findRegisterDefOperandIdx(Register Reg, const TargetRegisterInfo *TRI,
1575                                 bool isDead = false,
1576                                 bool Overlap = false) const;
1577 
1578   /// Wrapper for findRegisterDefOperandIdx, it returns
1579   /// a pointer to the MachineOperand rather than an index.
1580   MachineOperand *findRegisterDefOperand(Register Reg,
1581                                          const TargetRegisterInfo *TRI,
1582                                          bool isDead = false,
1583                                          bool Overlap = false) {
1584     int Idx = findRegisterDefOperandIdx(Reg, TRI, isDead, Overlap);
1585     return (Idx == -1) ? nullptr : &getOperand(Idx);
1586   }
1587 
1588   const MachineOperand *findRegisterDefOperand(Register Reg,
1589                                                const TargetRegisterInfo *TRI,
1590                                                bool isDead = false,
1591                                                bool Overlap = false) const {
1592     return const_cast<MachineInstr *>(this)->findRegisterDefOperand(
1593         Reg, TRI, isDead, Overlap);
1594   }
1595 
1596   /// Find the index of the first operand in the
1597   /// operand list that is used to represent the predicate. It returns -1 if
1598   /// none is found.
1599   int findFirstPredOperandIdx() const;
1600 
1601   /// Find the index of the flag word operand that
1602   /// corresponds to operand OpIdx on an inline asm instruction.  Returns -1 if
1603   /// getOperand(OpIdx) does not belong to an inline asm operand group.
1604   ///
1605   /// If GroupNo is not NULL, it will receive the number of the operand group
1606   /// containing OpIdx.
1607   int findInlineAsmFlagIdx(unsigned OpIdx, unsigned *GroupNo = nullptr) const;
1608 
1609   /// Compute the static register class constraint for operand OpIdx.
1610   /// For normal instructions, this is derived from the MCInstrDesc.
1611   /// For inline assembly it is derived from the flag words.
1612   ///
1613   /// Returns NULL if the static register class constraint cannot be
1614   /// determined.
1615   const TargetRegisterClass*
1616   getRegClassConstraint(unsigned OpIdx,
1617                         const TargetInstrInfo *TII,
1618                         const TargetRegisterInfo *TRI) const;
1619 
1620   /// Applies the constraints (def/use) implied by this MI on \p Reg to
1621   /// the given \p CurRC.
1622   /// If \p ExploreBundle is set and MI is part of a bundle, all the
1623   /// instructions inside the bundle will be taken into account. In other words,
1624   /// this method accumulates all the constraints of the operand of this MI and
1625   /// the related bundle if MI is a bundle or inside a bundle.
1626   ///
1627   /// Returns the register class that satisfies both \p CurRC and the
1628   /// constraints set by MI. Returns NULL if such a register class does not
1629   /// exist.
1630   ///
1631   /// \pre CurRC must not be NULL.
1632   const TargetRegisterClass *getRegClassConstraintEffectForVReg(
1633       Register Reg, const TargetRegisterClass *CurRC,
1634       const TargetInstrInfo *TII, const TargetRegisterInfo *TRI,
1635       bool ExploreBundle = false) const;
1636 
1637   /// Applies the constraints (def/use) implied by the \p OpIdx operand
1638   /// to the given \p CurRC.
1639   ///
1640   /// Returns the register class that satisfies both \p CurRC and the
1641   /// constraints set by \p OpIdx MI. Returns NULL if such a register class
1642   /// does not exist.
1643   ///
1644   /// \pre CurRC must not be NULL.
1645   /// \pre The operand at \p OpIdx must be a register.
1646   const TargetRegisterClass *
1647   getRegClassConstraintEffect(unsigned OpIdx, const TargetRegisterClass *CurRC,
1648                               const TargetInstrInfo *TII,
1649                               const TargetRegisterInfo *TRI) const;
1650 
1651   /// Add a tie between the register operands at DefIdx and UseIdx.
1652   /// The tie will cause the register allocator to ensure that the two
1653   /// operands are assigned the same physical register.
1654   ///
1655   /// Tied operands are managed automatically for explicit operands in the
1656   /// MCInstrDesc. This method is for exceptional cases like inline asm.
1657   void tieOperands(unsigned DefIdx, unsigned UseIdx);
1658 
1659   /// Given the index of a tied register operand, find the
1660   /// operand it is tied to. Defs are tied to uses and vice versa. Returns the
1661   /// index of the tied operand which must exist.
1662   unsigned findTiedOperandIdx(unsigned OpIdx) const;
1663 
1664   /// Given the index of a register def operand,
1665   /// check if the register def is tied to a source operand, due to either
1666   /// two-address elimination or inline assembly constraints. Returns the
1667   /// first tied use operand index by reference if UseOpIdx is not null.
1668   bool isRegTiedToUseOperand(unsigned DefOpIdx,
1669                              unsigned *UseOpIdx = nullptr) const {
1670     const MachineOperand &MO = getOperand(DefOpIdx);
1671     if (!MO.isReg() || !MO.isDef() || !MO.isTied())
1672       return false;
1673     if (UseOpIdx)
1674       *UseOpIdx = findTiedOperandIdx(DefOpIdx);
1675     return true;
1676   }
1677 
1678   /// Return true if the use operand of the specified index is tied to a def
1679   /// operand. It also returns the def operand index by reference if DefOpIdx
1680   /// is not null.
1681   bool isRegTiedToDefOperand(unsigned UseOpIdx,
1682                              unsigned *DefOpIdx = nullptr) const {
1683     const MachineOperand &MO = getOperand(UseOpIdx);
1684     if (!MO.isReg() || !MO.isUse() || !MO.isTied())
1685       return false;
1686     if (DefOpIdx)
1687       *DefOpIdx = findTiedOperandIdx(UseOpIdx);
1688     return true;
1689   }
1690 
1691   /// Clears kill flags on all operands.
1692   void clearKillInfo();
1693 
1694   /// Replace all occurrences of FromReg with ToReg:SubIdx,
1695   /// properly composing subreg indices where necessary.
1696   void substituteRegister(Register FromReg, Register ToReg, unsigned SubIdx,
1697                           const TargetRegisterInfo &RegInfo);
1698 
1699   /// We have determined MI kills a register. Look for the
1700   /// operand that uses it and mark it as IsKill. If AddIfNotFound is true,
1701   /// add a implicit operand if it's not found. Returns true if the operand
1702   /// exists / is added.
1703   bool addRegisterKilled(Register IncomingReg,
1704                          const TargetRegisterInfo *RegInfo,
1705                          bool AddIfNotFound = false);
1706 
1707   /// Clear all kill flags affecting Reg.  If RegInfo is provided, this includes
1708   /// all aliasing registers.
1709   void clearRegisterKills(Register Reg, const TargetRegisterInfo *RegInfo);
1710 
1711   /// We have determined MI defined a register without a use.
1712   /// Look for the operand that defines it and mark it as IsDead. If
1713   /// AddIfNotFound is true, add a implicit operand if it's not found. Returns
1714   /// true if the operand exists / is added.
1715   bool addRegisterDead(Register Reg, const TargetRegisterInfo *RegInfo,
1716                        bool AddIfNotFound = false);
1717 
1718   /// Clear all dead flags on operands defining register @p Reg.
1719   void clearRegisterDeads(Register Reg);
1720 
1721   /// Mark all subregister defs of register @p Reg with the undef flag.
1722   /// This function is used when we determined to have a subregister def in an
1723   /// otherwise undefined super register.
1724   void setRegisterDefReadUndef(Register Reg, bool IsUndef = true);
1725 
1726   /// We have determined MI defines a register. Make sure there is an operand
1727   /// defining Reg.
1728   void addRegisterDefined(Register Reg,
1729                           const TargetRegisterInfo *RegInfo = nullptr);
1730 
1731   /// Mark every physreg used by this instruction as
1732   /// dead except those in the UsedRegs list.
1733   ///
1734   /// On instructions with register mask operands, also add implicit-def
1735   /// operands for all registers in UsedRegs.
1736   void setPhysRegsDeadExcept(ArrayRef<Register> UsedRegs,
1737                              const TargetRegisterInfo &TRI);
1738 
1739   /// Return true if it is safe to move this instruction. If
1740   /// SawStore is set to true, it means that there is a store (or call) between
1741   /// the instruction's location and its intended destination.
1742   bool isSafeToMove(bool &SawStore) const;
1743 
1744   /// Return true if this instruction would be trivially dead if all of its
1745   /// defined registers were dead.
1746   bool wouldBeTriviallyDead() const;
1747 
1748   /// Check whether an MI is dead. If \p LivePhysRegs is provided, it is assumed
1749   /// to be at the position of MI and will be used to check the Liveness of
1750   /// physical register defs. If \p LivePhysRegs is not provided, this will
1751   /// pessimistically assume any PhysReg def is live.
1752   /// For trivially dead instructions (i.e. those without hard to model effects
1753   /// / wouldBeTriviallyDead), this checks deadness by analyzing defs of the
1754   /// MachineInstr. If the instruction wouldBeTriviallyDead, and  all the defs
1755   /// either have dead flags or have no uses, then the instruction is said to be
1756   /// dead.
1757   bool isDead(const MachineRegisterInfo &MRI,
1758               LiveRegUnits *LivePhysRegs = nullptr) const;
1759 
1760   /// Returns true if this instruction's memory access aliases the memory
1761   /// access of Other.
1762   //
1763   /// Assumes any physical registers used to compute addresses
1764   /// have the same value for both instructions.  Returns false if neither
1765   /// instruction writes to memory.
1766   ///
1767   /// @param AA Optional alias analysis, used to compare memory operands.
1768   /// @param Other MachineInstr to check aliasing against.
1769   /// @param UseTBAA Whether to pass TBAA information to alias analysis.
1770   bool mayAlias(BatchAAResults *AA, const MachineInstr &Other,
1771                 bool UseTBAA) const;
1772   bool mayAlias(AAResults *AA, const MachineInstr &Other, bool UseTBAA) const;
1773 
1774   /// Return true if this instruction may have an ordered
1775   /// or volatile memory reference, or if the information describing the memory
1776   /// reference is not available. Return false if it is known to have no
1777   /// ordered or volatile memory references.
1778   bool hasOrderedMemoryRef() const;
1779 
1780   /// Return true if this load instruction never traps and points to a memory
1781   /// location whose value doesn't change during the execution of this function.
1782   ///
1783   /// Examples include loading a value from the constant pool or from the
1784   /// argument area of a function (if it does not change).  If the instruction
1785   /// does multiple loads, this returns true only if all of the loads are
1786   /// dereferenceable and invariant.
1787   bool isDereferenceableInvariantLoad() const;
1788 
1789   /// If the specified instruction is a PHI that always merges together the
1790   /// same virtual register, return the register, otherwise return Register().
1791   Register isConstantValuePHI() const;
1792 
1793   /// Return true if this instruction has side effects that are not modeled
1794   /// by mayLoad / mayStore, etc.
1795   /// For all instructions, the property is encoded in MCInstrDesc::Flags
1796   /// (see MCInstrDesc::hasUnmodeledSideEffects(). The only exception is
1797   /// INLINEASM instruction, in which case the side effect property is encoded
1798   /// in one of its operands (see InlineAsm::Extra_HasSideEffect).
1799   ///
1800   bool hasUnmodeledSideEffects() const;
1801 
1802   /// Returns true if it is illegal to fold a load across this instruction.
1803   bool isLoadFoldBarrier() const;
1804 
1805   /// Return true if all the defs of this instruction are dead.
1806   bool allDefsAreDead() const;
1807 
1808   /// Return true if all the implicit defs of this instruction are dead.
1809   bool allImplicitDefsAreDead() const;
1810 
1811   /// Return a valid size if the instruction is a spill instruction.
1812   std::optional<LocationSize> getSpillSize(const TargetInstrInfo *TII) const;
1813 
1814   /// Return a valid size if the instruction is a folded spill instruction.
1815   std::optional<LocationSize>
1816   getFoldedSpillSize(const TargetInstrInfo *TII) const;
1817 
1818   /// Return a valid size if the instruction is a restore instruction.
1819   std::optional<LocationSize> getRestoreSize(const TargetInstrInfo *TII) const;
1820 
1821   /// Return a valid size if the instruction is a folded restore instruction.
1822   std::optional<LocationSize>
1823   getFoldedRestoreSize(const TargetInstrInfo *TII) const;
1824 
1825   /// Copy implicit register operands from specified
1826   /// instruction to this instruction.
1827   void copyImplicitOps(MachineFunction &MF, const MachineInstr &MI);
1828 
1829   /// Debugging support
1830   /// @{
1831   /// Determine the generic type to be printed (if needed) on uses and defs.
1832   LLT getTypeToPrint(unsigned OpIdx, SmallBitVector &PrintedTypes,
1833                      const MachineRegisterInfo &MRI) const;
1834 
1835   /// Return true when an instruction has tied register that can't be determined
1836   /// by the instruction's descriptor. This is useful for MIR printing, to
1837   /// determine whether we need to print the ties or not.
1838   bool hasComplexRegisterTies() const;
1839 
1840   /// Print this MI to \p OS.
1841   /// Don't print information that can be inferred from other instructions if
1842   /// \p IsStandalone is false. It is usually true when only a fragment of the
1843   /// function is printed.
1844   /// Only print the defs and the opcode if \p SkipOpers is true.
1845   /// Otherwise, also print operands if \p SkipDebugLoc is true.
1846   /// Otherwise, also print the debug loc, with a terminating newline.
1847   /// \p TII is used to print the opcode name.  If it's not present, but the
1848   /// MI is in a function, the opcode will be printed using the function's TII.
1849   void print(raw_ostream &OS, bool IsStandalone = true, bool SkipOpers = false,
1850              bool SkipDebugLoc = false, bool AddNewLine = true,
1851              const TargetInstrInfo *TII = nullptr) const;
1852   void print(raw_ostream &OS, ModuleSlotTracker &MST, bool IsStandalone = true,
1853              bool SkipOpers = false, bool SkipDebugLoc = false,
1854              bool AddNewLine = true,
1855              const TargetInstrInfo *TII = nullptr) const;
1856   void dump() const;
1857   /// Print on dbgs() the current instruction and the instructions defining its
1858   /// operands and so on until we reach \p MaxDepth.
1859   void dumpr(const MachineRegisterInfo &MRI,
1860              unsigned MaxDepth = UINT_MAX) const;
1861   /// @}
1862 
1863   //===--------------------------------------------------------------------===//
1864   // Accessors used to build up machine instructions.
1865 
1866   /// Add the specified operand to the instruction.  If it is an implicit
1867   /// operand, it is added to the end of the operand list.  If it is an
1868   /// explicit operand it is added at the end of the explicit operand list
1869   /// (before the first implicit operand).
1870   ///
1871   /// MF must be the machine function that was used to allocate this
1872   /// instruction.
1873   ///
1874   /// MachineInstrBuilder provides a more convenient interface for creating
1875   /// instructions and adding operands.
1876   void addOperand(MachineFunction &MF, const MachineOperand &Op);
1877 
1878   /// Add an operand without providing an MF reference. This only works for
1879   /// instructions that are inserted in a basic block.
1880   ///
1881   /// MachineInstrBuilder and the two-argument addOperand(MF, MO) should be
1882   /// preferred.
1883   void addOperand(const MachineOperand &Op);
1884 
1885   /// Inserts Ops BEFORE It. Can untie/retie tied operands.
1886   void insert(mop_iterator InsertBefore, ArrayRef<MachineOperand> Ops);
1887 
1888   /// Replace the instruction descriptor (thus opcode) of
1889   /// the current instruction with a new one.
1890   void setDesc(const MCInstrDesc &TID);
1891 
1892   /// Replace current source information with new such.
1893   /// Avoid using this, the constructor argument is preferable.
1894   void setDebugLoc(DebugLoc DL) {
1895     DbgLoc = std::move(DL);
1896     assert(DbgLoc.hasTrivialDestructor() && "Expected trivial destructor");
1897   }
1898 
1899   /// Erase an operand from an instruction, leaving it with one
1900   /// fewer operand than it started with.
1901   void removeOperand(unsigned OpNo);
1902 
1903   /// Clear this MachineInstr's memory reference descriptor list.  This resets
1904   /// the memrefs to their most conservative state.  This should be used only
1905   /// as a last resort since it greatly pessimizes our knowledge of the memory
1906   /// access performed by the instruction.
1907   void dropMemRefs(MachineFunction &MF);
1908 
1909   /// Assign this MachineInstr's memory reference descriptor list.
1910   ///
1911   /// Unlike other methods, this *will* allocate them into a new array
1912   /// associated with the provided `MachineFunction`.
1913   void setMemRefs(MachineFunction &MF, ArrayRef<MachineMemOperand *> MemRefs);
1914 
1915   /// Add a MachineMemOperand to the machine instruction.
1916   /// This function should be used only occasionally. The setMemRefs function
1917   /// is the primary method for setting up a MachineInstr's MemRefs list.
1918   void addMemOperand(MachineFunction &MF, MachineMemOperand *MO);
1919 
1920   /// Clone another MachineInstr's memory reference descriptor list and replace
1921   /// ours with it.
1922   ///
1923   /// Note that `*this` may be the incoming MI!
1924   ///
1925   /// Prefer this API whenever possible as it can avoid allocations in common
1926   /// cases.
1927   void cloneMemRefs(MachineFunction &MF, const MachineInstr &MI);
1928 
1929   /// Clone the merge of multiple MachineInstrs' memory reference descriptors
1930   /// list and replace ours with it.
1931   ///
1932   /// Note that `*this` may be one of the incoming MIs!
1933   ///
1934   /// Prefer this API whenever possible as it can avoid allocations in common
1935   /// cases.
1936   void cloneMergedMemRefs(MachineFunction &MF,
1937                           ArrayRef<const MachineInstr *> MIs);
1938 
1939   /// Set a symbol that will be emitted just prior to the instruction itself.
1940   ///
1941   /// Setting this to a null pointer will remove any such symbol.
1942   ///
1943   /// FIXME: This is not fully implemented yet.
1944   void setPreInstrSymbol(MachineFunction &MF, MCSymbol *Symbol);
1945 
1946   /// Set a symbol that will be emitted just after the instruction itself.
1947   ///
1948   /// Setting this to a null pointer will remove any such symbol.
1949   ///
1950   /// FIXME: This is not fully implemented yet.
1951   void setPostInstrSymbol(MachineFunction &MF, MCSymbol *Symbol);
1952 
1953   /// Clone another MachineInstr's pre- and post- instruction symbols and
1954   /// replace ours with it.
1955   void cloneInstrSymbols(MachineFunction &MF, const MachineInstr &MI);
1956 
1957   /// Set a marker on instructions that denotes where we should create and emit
1958   /// heap alloc site labels. This waits until after instruction selection and
1959   /// optimizations to create the label, so it should still work if the
1960   /// instruction is removed or duplicated.
1961   void setHeapAllocMarker(MachineFunction &MF, MDNode *MD);
1962 
1963   // Set metadata on instructions that say which sections to emit instruction
1964   // addresses into.
1965   void setPCSections(MachineFunction &MF, MDNode *MD);
1966 
1967   void setMMRAMetadata(MachineFunction &MF, MDNode *MMRAs);
1968 
1969   /// Set the CFI type for the instruction.
1970   void setCFIType(MachineFunction &MF, uint32_t Type);
1971 
1972   /// Return the MIFlags which represent both MachineInstrs. This
1973   /// should be used when merging two MachineInstrs into one. This routine does
1974   /// not modify the MIFlags of this MachineInstr.
1975   uint32_t mergeFlagsWith(const MachineInstr& Other) const;
1976 
1977   static uint32_t copyFlagsFromInstruction(const Instruction &I);
1978 
1979   /// Copy all flags to MachineInst MIFlags
1980   void copyIRFlags(const Instruction &I);
1981 
1982   /// Break any tie involving OpIdx.
1983   void untieRegOperand(unsigned OpIdx) {
1984     MachineOperand &MO = getOperand(OpIdx);
1985     if (MO.isReg() && MO.isTied()) {
1986       getOperand(findTiedOperandIdx(OpIdx)).TiedTo = 0;
1987       MO.TiedTo = 0;
1988     }
1989   }
1990 
1991   /// Add all implicit def and use operands to this instruction.
1992   void addImplicitDefUseOperands(MachineFunction &MF);
1993 
1994   /// Scan instructions immediately following MI and collect any matching
1995   /// DBG_VALUEs.
1996   void collectDebugValues(SmallVectorImpl<MachineInstr *> &DbgValues);
1997 
1998   /// Find all DBG_VALUEs that point to the register def in this instruction
1999   /// and point them to \p Reg instead.
2000   void changeDebugValuesDefReg(Register Reg);
2001 
2002   /// Sets all register debug operands in this debug value instruction to be
2003   /// undef.
2004   void setDebugValueUndef() {
2005     assert(isDebugValue() && "Must be a debug value instruction.");
2006     for (MachineOperand &MO : debug_operands()) {
2007       if (MO.isReg()) {
2008         MO.setReg(0);
2009         MO.setSubReg(0);
2010       }
2011     }
2012   }
2013 
2014   std::tuple<Register, Register> getFirst2Regs() const {
2015     return std::tuple(getOperand(0).getReg(), getOperand(1).getReg());
2016   }
2017 
2018   std::tuple<Register, Register, Register> getFirst3Regs() const {
2019     return std::tuple(getOperand(0).getReg(), getOperand(1).getReg(),
2020                       getOperand(2).getReg());
2021   }
2022 
2023   std::tuple<Register, Register, Register, Register> getFirst4Regs() const {
2024     return std::tuple(getOperand(0).getReg(), getOperand(1).getReg(),
2025                       getOperand(2).getReg(), getOperand(3).getReg());
2026   }
2027 
2028   std::tuple<Register, Register, Register, Register, Register>
2029   getFirst5Regs() const {
2030     return std::tuple(getOperand(0).getReg(), getOperand(1).getReg(),
2031                       getOperand(2).getReg(), getOperand(3).getReg(),
2032                       getOperand(4).getReg());
2033   }
2034 
2035   std::tuple<LLT, LLT> getFirst2LLTs() const;
2036   std::tuple<LLT, LLT, LLT> getFirst3LLTs() const;
2037   std::tuple<LLT, LLT, LLT, LLT> getFirst4LLTs() const;
2038   std::tuple<LLT, LLT, LLT, LLT, LLT> getFirst5LLTs() const;
2039 
2040   std::tuple<Register, LLT, Register, LLT> getFirst2RegLLTs() const;
2041   std::tuple<Register, LLT, Register, LLT, Register, LLT>
2042   getFirst3RegLLTs() const;
2043   std::tuple<Register, LLT, Register, LLT, Register, LLT, Register, LLT>
2044   getFirst4RegLLTs() const;
2045   std::tuple<Register, LLT, Register, LLT, Register, LLT, Register, LLT,
2046              Register, LLT>
2047   getFirst5RegLLTs() const;
2048 
2049 private:
2050   /// If this instruction is embedded into a MachineFunction, return the
2051   /// MachineRegisterInfo object for the current function, otherwise
2052   /// return null.
2053   MachineRegisterInfo *getRegInfo();
2054   const MachineRegisterInfo *getRegInfo() const;
2055 
2056   /// Unlink all of the register operands in this instruction from their
2057   /// respective use lists.  This requires that the operands already be on their
2058   /// use lists.
2059   void removeRegOperandsFromUseLists(MachineRegisterInfo&);
2060 
2061   /// Add all of the register operands in this instruction from their
2062   /// respective use lists.  This requires that the operands not be on their
2063   /// use lists yet.
2064   void addRegOperandsToUseLists(MachineRegisterInfo&);
2065 
2066   /// Slow path for hasProperty when we're dealing with a bundle.
2067   bool hasPropertyInBundle(uint64_t Mask, QueryType Type) const;
2068 
2069   /// Implements the logic of getRegClassConstraintEffectForVReg for the
2070   /// this MI and the given operand index \p OpIdx.
2071   /// If the related operand does not constrained Reg, this returns CurRC.
2072   const TargetRegisterClass *getRegClassConstraintEffectForVRegImpl(
2073       unsigned OpIdx, Register Reg, const TargetRegisterClass *CurRC,
2074       const TargetInstrInfo *TII, const TargetRegisterInfo *TRI) const;
2075 
2076   /// Stores extra instruction information inline or allocates as ExtraInfo
2077   /// based on the number of pointers.
2078   void setExtraInfo(MachineFunction &MF, ArrayRef<MachineMemOperand *> MMOs,
2079                     MCSymbol *PreInstrSymbol, MCSymbol *PostInstrSymbol,
2080                     MDNode *HeapAllocMarker, MDNode *PCSections,
2081                     uint32_t CFIType, MDNode *MMRAs);
2082 };
2083 
2084 /// Special DenseMapInfo traits to compare MachineInstr* by *value* of the
2085 /// instruction rather than by pointer value.
2086 /// The hashing and equality testing functions ignore definitions so this is
2087 /// useful for CSE, etc.
2088 struct MachineInstrExpressionTrait : DenseMapInfo<MachineInstr*> {
2089   static inline MachineInstr *getEmptyKey() {
2090     return nullptr;
2091   }
2092 
2093   static inline MachineInstr *getTombstoneKey() {
2094     return reinterpret_cast<MachineInstr*>(-1);
2095   }
2096 
2097   static unsigned getHashValue(const MachineInstr* const &MI);
2098 
2099   static bool isEqual(const MachineInstr* const &LHS,
2100                       const MachineInstr* const &RHS) {
2101     if (RHS == getEmptyKey() || RHS == getTombstoneKey() ||
2102         LHS == getEmptyKey() || LHS == getTombstoneKey())
2103       return LHS == RHS;
2104     return LHS->isIdenticalTo(*RHS, MachineInstr::IgnoreVRegDefs);
2105   }
2106 };
2107 
2108 //===----------------------------------------------------------------------===//
2109 // Debugging Support
2110 
2111 inline raw_ostream& operator<<(raw_ostream &OS, const MachineInstr &MI) {
2112   MI.print(OS);
2113   return OS;
2114 }
2115 
2116 } // end namespace llvm
2117 
2118 #endif // LLVM_CODEGEN_MACHINEINSTR_H
2119