1 //===-- ARMBaseInstrInfo.h - ARM Base Instruction Information ---*- 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 Base ARM implementation of the TargetInstrInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_ARM_ARMBASEINSTRINFO_H
14 #define LLVM_LIB_TARGET_ARM_ARMBASEINSTRINFO_H
15 
16 #include "MCTargetDesc/ARMBaseInfo.h"
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/SmallSet.h"
19 #include "llvm/CodeGen/MachineBasicBlock.h"
20 #include "llvm/CodeGen/MachineInstr.h"
21 #include "llvm/CodeGen/MachineInstrBuilder.h"
22 #include "llvm/CodeGen/MachineOperand.h"
23 #include "llvm/CodeGen/TargetInstrInfo.h"
24 #include <array>
25 #include <cstdint>
26 
27 #define GET_INSTRINFO_HEADER
28 #include "ARMGenInstrInfo.inc"
29 
30 namespace llvm {
31 
32 class ARMBaseRegisterInfo;
33 class ARMSubtarget;
34 
35 class ARMBaseInstrInfo : public ARMGenInstrInfo {
36   const ARMSubtarget &Subtarget;
37 
38 protected:
39   // Can be only subclassed.
40   explicit ARMBaseInstrInfo(const ARMSubtarget &STI);
41 
42   void expandLoadStackGuardBase(MachineBasicBlock::iterator MI,
43                                 unsigned LoadImmOpc, unsigned LoadOpc) const;
44 
45   /// Build the equivalent inputs of a REG_SEQUENCE for the given \p MI
46   /// and \p DefIdx.
47   /// \p [out] InputRegs of the equivalent REG_SEQUENCE. Each element of
48   /// the list is modeled as <Reg:SubReg, SubIdx>.
49   /// E.g., REG_SEQUENCE %1:sub1, sub0, %2, sub1 would produce
50   /// two elements:
51   /// - %1:sub1, sub0
52   /// - %2<:0>, sub1
53   ///
54   /// \returns true if it is possible to build such an input sequence
55   /// with the pair \p MI, \p DefIdx. False otherwise.
56   ///
57   /// \pre MI.isRegSequenceLike().
58   bool getRegSequenceLikeInputs(
59       const MachineInstr &MI, unsigned DefIdx,
60       SmallVectorImpl<RegSubRegPairAndIdx> &InputRegs) const override;
61 
62   /// Build the equivalent inputs of a EXTRACT_SUBREG for the given \p MI
63   /// and \p DefIdx.
64   /// \p [out] InputReg of the equivalent EXTRACT_SUBREG.
65   /// E.g., EXTRACT_SUBREG %1:sub1, sub0, sub1 would produce:
66   /// - %1:sub1, sub0
67   ///
68   /// \returns true if it is possible to build such an input sequence
69   /// with the pair \p MI, \p DefIdx. False otherwise.
70   ///
71   /// \pre MI.isExtractSubregLike().
72   bool getExtractSubregLikeInputs(const MachineInstr &MI, unsigned DefIdx,
73                                   RegSubRegPairAndIdx &InputReg) const override;
74 
75   /// Build the equivalent inputs of a INSERT_SUBREG for the given \p MI
76   /// and \p DefIdx.
77   /// \p [out] BaseReg and \p [out] InsertedReg contain
78   /// the equivalent inputs of INSERT_SUBREG.
79   /// E.g., INSERT_SUBREG %0:sub0, %1:sub1, sub3 would produce:
80   /// - BaseReg: %0:sub0
81   /// - InsertedReg: %1:sub1, sub3
82   ///
83   /// \returns true if it is possible to build such an input sequence
84   /// with the pair \p MI, \p DefIdx. False otherwise.
85   ///
86   /// \pre MI.isInsertSubregLike().
87   bool
88   getInsertSubregLikeInputs(const MachineInstr &MI, unsigned DefIdx,
89                             RegSubRegPair &BaseReg,
90                             RegSubRegPairAndIdx &InsertedReg) const override;
91 
92   /// Commutes the operands in the given instruction.
93   /// The commutable operands are specified by their indices OpIdx1 and OpIdx2.
94   ///
95   /// Do not call this method for a non-commutable instruction or for
96   /// non-commutable pair of operand indices OpIdx1 and OpIdx2.
97   /// Even though the instruction is commutable, the method may still
98   /// fail to commute the operands, null pointer is returned in such cases.
99   MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
100                                        unsigned OpIdx1,
101                                        unsigned OpIdx2) const override;
102   /// If the specific machine instruction is an instruction that moves/copies
103   /// value from one register to another register return destination and source
104   /// registers as machine operands.
105   Optional<DestSourcePair>
106   isCopyInstrImpl(const MachineInstr &MI) const override;
107 
108 public:
109   // Return whether the target has an explicit NOP encoding.
110   bool hasNOP() const;
111 
112   // Return the non-pre/post incrementing version of 'Opc'. Return 0
113   // if there is not such an opcode.
114   virtual unsigned getUnindexedOpcode(unsigned Opc) const = 0;
115 
116   MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
117                                       MachineInstr &MI,
118                                       LiveVariables *LV) const override;
119 
120   virtual const ARMBaseRegisterInfo &getRegisterInfo() const = 0;
121   const ARMSubtarget &getSubtarget() const { return Subtarget; }
122 
123   ScheduleHazardRecognizer *
124   CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
125                                const ScheduleDAG *DAG) const override;
126 
127   ScheduleHazardRecognizer *
128   CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
129                                      const ScheduleDAG *DAG) const override;
130 
131   // Branch analysis.
132   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
133                      MachineBasicBlock *&FBB,
134                      SmallVectorImpl<MachineOperand> &Cond,
135                      bool AllowModify = false) const override;
136   unsigned removeBranch(MachineBasicBlock &MBB,
137                         int *BytesRemoved = nullptr) const override;
138   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
139                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
140                         const DebugLoc &DL,
141                         int *BytesAdded = nullptr) const override;
142 
143   bool
144   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
145 
146   // Predication support.
147   bool isPredicated(const MachineInstr &MI) const override;
148 
149   ARMCC::CondCodes getPredicate(const MachineInstr &MI) const {
150     int PIdx = MI.findFirstPredOperandIdx();
151     return PIdx != -1 ? (ARMCC::CondCodes)MI.getOperand(PIdx).getImm()
152                       : ARMCC::AL;
153   }
154 
155   bool PredicateInstruction(MachineInstr &MI,
156                             ArrayRef<MachineOperand> Pred) const override;
157 
158   bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
159                          ArrayRef<MachineOperand> Pred2) const override;
160 
161   bool DefinesPredicate(MachineInstr &MI,
162                         std::vector<MachineOperand> &Pred) const override;
163 
164   bool isPredicable(const MachineInstr &MI) const override;
165 
166   // CPSR defined in instruction
167   static bool isCPSRDefined(const MachineInstr &MI);
168   bool isAddrMode3OpImm(const MachineInstr &MI, unsigned Op) const;
169   bool isAddrMode3OpMinusReg(const MachineInstr &MI, unsigned Op) const;
170 
171   // Load, scaled register offset
172   bool isLdstScaledReg(const MachineInstr &MI, unsigned Op) const;
173   // Load, scaled register offset, not plus LSL2
174   bool isLdstScaledRegNotPlusLsl2(const MachineInstr &MI, unsigned Op) const;
175   // Minus reg for ldstso addr mode
176   bool isLdstSoMinusReg(const MachineInstr &MI, unsigned Op) const;
177   // Scaled register offset in address mode 2
178   bool isAm2ScaledReg(const MachineInstr &MI, unsigned Op) const;
179   // Load multiple, base reg in list
180   bool isLDMBaseRegInList(const MachineInstr &MI) const;
181   // get LDM variable defs size
182   unsigned getLDMVariableDefsSize(const MachineInstr &MI) const;
183 
184   /// GetInstSize - Returns the size of the specified MachineInstr.
185   ///
186   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
187 
188   unsigned isLoadFromStackSlot(const MachineInstr &MI,
189                                int &FrameIndex) const override;
190   unsigned isStoreToStackSlot(const MachineInstr &MI,
191                               int &FrameIndex) const override;
192   unsigned isLoadFromStackSlotPostFE(const MachineInstr &MI,
193                                      int &FrameIndex) const override;
194   unsigned isStoreToStackSlotPostFE(const MachineInstr &MI,
195                                     int &FrameIndex) const override;
196 
197   void copyToCPSR(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
198                   unsigned SrcReg, bool KillSrc,
199                   const ARMSubtarget &Subtarget) const;
200   void copyFromCPSR(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
201                     unsigned DestReg, bool KillSrc,
202                     const ARMSubtarget &Subtarget) const;
203 
204   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
205                    const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
206                    bool KillSrc) const override;
207 
208   void storeRegToStackSlot(MachineBasicBlock &MBB,
209                            MachineBasicBlock::iterator MBBI,
210                            unsigned SrcReg, bool isKill, int FrameIndex,
211                            const TargetRegisterClass *RC,
212                            const TargetRegisterInfo *TRI) const override;
213 
214   void loadRegFromStackSlot(MachineBasicBlock &MBB,
215                             MachineBasicBlock::iterator MBBI,
216                             unsigned DestReg, int FrameIndex,
217                             const TargetRegisterClass *RC,
218                             const TargetRegisterInfo *TRI) const override;
219 
220   bool expandPostRAPseudo(MachineInstr &MI) const override;
221 
222   bool shouldSink(const MachineInstr &MI) const override;
223 
224   void reMaterialize(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
225                      unsigned DestReg, unsigned SubIdx,
226                      const MachineInstr &Orig,
227                      const TargetRegisterInfo &TRI) const override;
228 
229   MachineInstr &
230   duplicate(MachineBasicBlock &MBB, MachineBasicBlock::iterator InsertBefore,
231             const MachineInstr &Orig) const override;
232 
233   const MachineInstrBuilder &AddDReg(MachineInstrBuilder &MIB, unsigned Reg,
234                                      unsigned SubIdx, unsigned State,
235                                      const TargetRegisterInfo *TRI) const;
236 
237   bool produceSameValue(const MachineInstr &MI0, const MachineInstr &MI1,
238                         const MachineRegisterInfo *MRI) const override;
239 
240   /// areLoadsFromSameBasePtr - This is used by the pre-regalloc scheduler to
241   /// determine if two loads are loading from the same base address. It should
242   /// only return true if the base pointers are the same and the only
243   /// differences between the two addresses is the offset. It also returns the
244   /// offsets by reference.
245   bool areLoadsFromSameBasePtr(SDNode *Load1, SDNode *Load2, int64_t &Offset1,
246                                int64_t &Offset2) const override;
247 
248   /// shouldScheduleLoadsNear - This is a used by the pre-regalloc scheduler to
249   /// determine (in conjunction with areLoadsFromSameBasePtr) if two loads
250   /// should be scheduled togther. On some targets if two loads are loading from
251   /// addresses in the same cache line, it's better if they are scheduled
252   /// together. This function takes two integers that represent the load offsets
253   /// from the common base address. It returns true if it decides it's desirable
254   /// to schedule the two loads together. "NumLoads" is the number of loads that
255   /// have already been scheduled after Load1.
256   bool shouldScheduleLoadsNear(SDNode *Load1, SDNode *Load2,
257                                int64_t Offset1, int64_t Offset2,
258                                unsigned NumLoads) const override;
259 
260   bool isSchedulingBoundary(const MachineInstr &MI,
261                             const MachineBasicBlock *MBB,
262                             const MachineFunction &MF) const override;
263 
264   bool isProfitableToIfCvt(MachineBasicBlock &MBB,
265                            unsigned NumCycles, unsigned ExtraPredCycles,
266                            BranchProbability Probability) const override;
267 
268   bool isProfitableToIfCvt(MachineBasicBlock &TMBB, unsigned NumT,
269                            unsigned ExtraT, MachineBasicBlock &FMBB,
270                            unsigned NumF, unsigned ExtraF,
271                            BranchProbability Probability) const override;
272 
273   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
274                                  BranchProbability Probability) const override {
275     return NumCycles == 1;
276   }
277 
278   unsigned extraSizeToPredicateInstructions(const MachineFunction &MF,
279                                             unsigned NumInsts) const override;
280   unsigned predictBranchSizeForIfCvt(MachineInstr &MI) const override;
281 
282   bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
283                                  MachineBasicBlock &FMBB) const override;
284 
285   /// analyzeCompare - For a comparison instruction, return the source registers
286   /// in SrcReg and SrcReg2 if having two register operands, and the value it
287   /// compares against in CmpValue. Return true if the comparison instruction
288   /// can be analyzed.
289   bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
290                       unsigned &SrcReg2, int &CmpMask,
291                       int &CmpValue) const override;
292 
293   /// optimizeCompareInstr - Convert the instruction to set the zero flag so
294   /// that we can remove a "comparison with zero"; Remove a redundant CMP
295   /// instruction if the flags can be updated in the same way by an earlier
296   /// instruction such as SUB.
297   bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
298                             unsigned SrcReg2, int CmpMask, int CmpValue,
299                             const MachineRegisterInfo *MRI) const override;
300 
301   bool analyzeSelect(const MachineInstr &MI,
302                      SmallVectorImpl<MachineOperand> &Cond, unsigned &TrueOp,
303                      unsigned &FalseOp, bool &Optimizable) const override;
304 
305   MachineInstr *optimizeSelect(MachineInstr &MI,
306                                SmallPtrSetImpl<MachineInstr *> &SeenMIs,
307                                bool) const override;
308 
309   /// FoldImmediate - 'Reg' is known to be defined by a move immediate
310   /// instruction, try to fold the immediate into the use instruction.
311   bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, unsigned Reg,
312                      MachineRegisterInfo *MRI) const override;
313 
314   unsigned getNumMicroOps(const InstrItineraryData *ItinData,
315                           const MachineInstr &MI) const override;
316 
317   int getOperandLatency(const InstrItineraryData *ItinData,
318                         const MachineInstr &DefMI, unsigned DefIdx,
319                         const MachineInstr &UseMI,
320                         unsigned UseIdx) const override;
321   int getOperandLatency(const InstrItineraryData *ItinData,
322                         SDNode *DefNode, unsigned DefIdx,
323                         SDNode *UseNode, unsigned UseIdx) const override;
324 
325   /// VFP/NEON execution domains.
326   std::pair<uint16_t, uint16_t>
327   getExecutionDomain(const MachineInstr &MI) const override;
328   void setExecutionDomain(MachineInstr &MI, unsigned Domain) const override;
329 
330   unsigned
331   getPartialRegUpdateClearance(const MachineInstr &, unsigned,
332                                const TargetRegisterInfo *) const override;
333   void breakPartialRegDependency(MachineInstr &, unsigned,
334                                  const TargetRegisterInfo *TRI) const override;
335 
336   /// Get the number of addresses by LDM or VLDM or zero for unknown.
337   unsigned getNumLDMAddresses(const MachineInstr &MI) const;
338 
339   std::pair<unsigned, unsigned>
340   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
341   ArrayRef<std::pair<unsigned, const char *>>
342   getSerializableDirectMachineOperandTargetFlags() const override;
343   ArrayRef<std::pair<unsigned, const char *>>
344   getSerializableBitmaskMachineOperandTargetFlags() const override;
345 
346 private:
347   unsigned getInstBundleLength(const MachineInstr &MI) const;
348 
349   int getVLDMDefCycle(const InstrItineraryData *ItinData,
350                       const MCInstrDesc &DefMCID,
351                       unsigned DefClass,
352                       unsigned DefIdx, unsigned DefAlign) const;
353   int getLDMDefCycle(const InstrItineraryData *ItinData,
354                      const MCInstrDesc &DefMCID,
355                      unsigned DefClass,
356                      unsigned DefIdx, unsigned DefAlign) const;
357   int getVSTMUseCycle(const InstrItineraryData *ItinData,
358                       const MCInstrDesc &UseMCID,
359                       unsigned UseClass,
360                       unsigned UseIdx, unsigned UseAlign) const;
361   int getSTMUseCycle(const InstrItineraryData *ItinData,
362                      const MCInstrDesc &UseMCID,
363                      unsigned UseClass,
364                      unsigned UseIdx, unsigned UseAlign) const;
365   int getOperandLatency(const InstrItineraryData *ItinData,
366                         const MCInstrDesc &DefMCID,
367                         unsigned DefIdx, unsigned DefAlign,
368                         const MCInstrDesc &UseMCID,
369                         unsigned UseIdx, unsigned UseAlign) const;
370 
371   int getOperandLatencyImpl(const InstrItineraryData *ItinData,
372                             const MachineInstr &DefMI, unsigned DefIdx,
373                             const MCInstrDesc &DefMCID, unsigned DefAdj,
374                             const MachineOperand &DefMO, unsigned Reg,
375                             const MachineInstr &UseMI, unsigned UseIdx,
376                             const MCInstrDesc &UseMCID, unsigned UseAdj) const;
377 
378   unsigned getPredicationCost(const MachineInstr &MI) const override;
379 
380   unsigned getInstrLatency(const InstrItineraryData *ItinData,
381                            const MachineInstr &MI,
382                            unsigned *PredCost = nullptr) const override;
383 
384   int getInstrLatency(const InstrItineraryData *ItinData,
385                       SDNode *Node) const override;
386 
387   bool hasHighOperandLatency(const TargetSchedModel &SchedModel,
388                              const MachineRegisterInfo *MRI,
389                              const MachineInstr &DefMI, unsigned DefIdx,
390                              const MachineInstr &UseMI,
391                              unsigned UseIdx) const override;
392   bool hasLowDefLatency(const TargetSchedModel &SchedModel,
393                         const MachineInstr &DefMI,
394                         unsigned DefIdx) const override;
395 
396   /// verifyInstruction - Perform target specific instruction verification.
397   bool verifyInstruction(const MachineInstr &MI,
398                          StringRef &ErrInfo) const override;
399 
400   virtual void expandLoadStackGuard(MachineBasicBlock::iterator MI) const = 0;
401 
402   void expandMEMCPY(MachineBasicBlock::iterator) const;
403 
404   /// Identify instructions that can be folded into a MOVCC instruction, and
405   /// return the defining instruction.
406   MachineInstr *canFoldIntoMOVCC(unsigned Reg, const MachineRegisterInfo &MRI,
407                                  const TargetInstrInfo *TII) const;
408 
409 private:
410   /// Modeling special VFP / NEON fp MLA / MLS hazards.
411 
412   /// MLxEntryMap - Map fp MLA / MLS to the corresponding entry in the internal
413   /// MLx table.
414   DenseMap<unsigned, unsigned> MLxEntryMap;
415 
416   /// MLxHazardOpcodes - Set of add / sub and multiply opcodes that would cause
417   /// stalls when scheduled together with fp MLA / MLS opcodes.
418   SmallSet<unsigned, 16> MLxHazardOpcodes;
419 
420 public:
421   /// isFpMLxInstruction - Return true if the specified opcode is a fp MLA / MLS
422   /// instruction.
423   bool isFpMLxInstruction(unsigned Opcode) const {
424     return MLxEntryMap.count(Opcode);
425   }
426 
427   /// isFpMLxInstruction - This version also returns the multiply opcode and the
428   /// addition / subtraction opcode to expand to. Return true for 'HasLane' for
429   /// the MLX instructions with an extra lane operand.
430   bool isFpMLxInstruction(unsigned Opcode, unsigned &MulOpc,
431                           unsigned &AddSubOpc, bool &NegAcc,
432                           bool &HasLane) const;
433 
434   /// canCauseFpMLxStall - Return true if an instruction of the specified opcode
435   /// will cause stalls when scheduled after (within 4-cycle window) a fp
436   /// MLA / MLS instruction.
437   bool canCauseFpMLxStall(unsigned Opcode) const {
438     return MLxHazardOpcodes.count(Opcode);
439   }
440 
441   /// Returns true if the instruction has a shift by immediate that can be
442   /// executed in one cycle less.
443   bool isSwiftFastImmShift(const MachineInstr *MI) const;
444 
445   /// Returns predicate register associated with the given frame instruction.
446   unsigned getFramePred(const MachineInstr &MI) const {
447     assert(isFrameInstr(MI));
448     // Operands of ADJCALLSTACKDOWN/ADJCALLSTACKUP:
449     // - argument declared in the pattern:
450     // 0 - frame size
451     // 1 - arg of CALLSEQ_START/CALLSEQ_END
452     // 2 - predicate code (like ARMCC::AL)
453     // - added by predOps:
454     // 3 - predicate reg
455     return MI.getOperand(3).getReg();
456   }
457 
458   Optional<RegImmPair> isAddImmediate(const MachineInstr &MI,
459                                       Register Reg) const override;
460 };
461 
462 /// Get the operands corresponding to the given \p Pred value. By default, the
463 /// predicate register is assumed to be 0 (no register), but you can pass in a
464 /// \p PredReg if that is not the case.
465 static inline std::array<MachineOperand, 2> predOps(ARMCC::CondCodes Pred,
466                                                     unsigned PredReg = 0) {
467   return {{MachineOperand::CreateImm(static_cast<int64_t>(Pred)),
468            MachineOperand::CreateReg(PredReg, false)}};
469 }
470 
471 /// Get the operand corresponding to the conditional code result. By default,
472 /// this is 0 (no register).
473 static inline MachineOperand condCodeOp(unsigned CCReg = 0) {
474   return MachineOperand::CreateReg(CCReg, false);
475 }
476 
477 /// Get the operand corresponding to the conditional code result for Thumb1.
478 /// This operand will always refer to CPSR and it will have the Define flag set.
479 /// You can optionally set the Dead flag by means of \p isDead.
480 static inline MachineOperand t1CondCodeOp(bool isDead = false) {
481   return MachineOperand::CreateReg(ARM::CPSR,
482                                    /*Define*/ true, /*Implicit*/ false,
483                                    /*Kill*/ false, isDead);
484 }
485 
486 static inline
487 bool isUncondBranchOpcode(int Opc) {
488   return Opc == ARM::B || Opc == ARM::tB || Opc == ARM::t2B;
489 }
490 
491 // This table shows the VPT instruction variants, i.e. the different
492 // mask field encodings, see also B5.6. Predication/conditional execution in
493 // the ArmARM.
494 enum VPTMaskValue {
495   T     =  8, // 0b1000
496   TT    =  4, // 0b0100
497   TE    = 12, // 0b1100
498   TTT   =  2, // 0b0010
499   TTE   =  6, // 0b0110
500   TEE   = 10, // 0b1010
501   TET   = 14, // 0b1110
502   TTTT  =  1, // 0b0001
503   TTTE  =  3, // 0b0011
504   TTEE  =  5, // 0b0101
505   TTET  =  7, // 0b0111
506   TEEE  =  9, // 0b1001
507   TEET  = 11, // 0b1011
508   TETT  = 13, // 0b1101
509   TETE  = 15  // 0b1111
510 };
511 
512 static inline bool isVPTOpcode(int Opc) {
513   return Opc == ARM::MVE_VPTv16i8 || Opc == ARM::MVE_VPTv16u8 ||
514          Opc == ARM::MVE_VPTv16s8 || Opc == ARM::MVE_VPTv8i16 ||
515          Opc == ARM::MVE_VPTv8u16 || Opc == ARM::MVE_VPTv8s16 ||
516          Opc == ARM::MVE_VPTv4i32 || Opc == ARM::MVE_VPTv4u32 ||
517          Opc == ARM::MVE_VPTv4s32 || Opc == ARM::MVE_VPTv4f32 ||
518          Opc == ARM::MVE_VPTv8f16 || Opc == ARM::MVE_VPTv16i8r ||
519          Opc == ARM::MVE_VPTv16u8r || Opc == ARM::MVE_VPTv16s8r ||
520          Opc == ARM::MVE_VPTv8i16r || Opc == ARM::MVE_VPTv8u16r ||
521          Opc == ARM::MVE_VPTv8s16r || Opc == ARM::MVE_VPTv4i32r ||
522          Opc == ARM::MVE_VPTv4u32r || Opc == ARM::MVE_VPTv4s32r ||
523          Opc == ARM::MVE_VPTv4f32r || Opc == ARM::MVE_VPTv8f16r ||
524          Opc == ARM::MVE_VPST;
525 }
526 
527 static inline
528 unsigned VCMPOpcodeToVPT(unsigned Opcode) {
529   switch (Opcode) {
530   default:
531     return 0;
532   case ARM::MVE_VCMPf32:
533     return ARM::MVE_VPTv4f32;
534   case ARM::MVE_VCMPf16:
535     return ARM::MVE_VPTv8f16;
536   case ARM::MVE_VCMPi8:
537     return ARM::MVE_VPTv16i8;
538   case ARM::MVE_VCMPi16:
539     return ARM::MVE_VPTv8i16;
540   case ARM::MVE_VCMPi32:
541     return ARM::MVE_VPTv4i32;
542   case ARM::MVE_VCMPu8:
543     return ARM::MVE_VPTv16u8;
544   case ARM::MVE_VCMPu16:
545     return ARM::MVE_VPTv8u16;
546   case ARM::MVE_VCMPu32:
547     return ARM::MVE_VPTv4u32;
548   case ARM::MVE_VCMPs8:
549     return ARM::MVE_VPTv16s8;
550   case ARM::MVE_VCMPs16:
551     return ARM::MVE_VPTv8s16;
552   case ARM::MVE_VCMPs32:
553     return ARM::MVE_VPTv4s32;
554 
555   case ARM::MVE_VCMPf32r:
556     return ARM::MVE_VPTv4f32r;
557   case ARM::MVE_VCMPf16r:
558     return ARM::MVE_VPTv8f16r;
559   case ARM::MVE_VCMPi8r:
560     return ARM::MVE_VPTv16i8r;
561   case ARM::MVE_VCMPi16r:
562     return ARM::MVE_VPTv8i16r;
563   case ARM::MVE_VCMPi32r:
564     return ARM::MVE_VPTv4i32r;
565   case ARM::MVE_VCMPu8r:
566     return ARM::MVE_VPTv16u8r;
567   case ARM::MVE_VCMPu16r:
568     return ARM::MVE_VPTv8u16r;
569   case ARM::MVE_VCMPu32r:
570     return ARM::MVE_VPTv4u32r;
571   case ARM::MVE_VCMPs8r:
572     return ARM::MVE_VPTv16s8r;
573   case ARM::MVE_VCMPs16r:
574     return ARM::MVE_VPTv8s16r;
575   case ARM::MVE_VCMPs32r:
576     return ARM::MVE_VPTv4s32r;
577   }
578 }
579 
580 static inline
581 unsigned VCTPOpcodeToLSTP(unsigned Opcode, bool IsDoLoop) {
582   switch (Opcode) {
583   default:
584     llvm_unreachable("unhandled vctp opcode");
585     break;
586   case ARM::MVE_VCTP8:
587     return IsDoLoop ? ARM::MVE_DLSTP_8 : ARM::MVE_WLSTP_8;
588   case ARM::MVE_VCTP16:
589     return IsDoLoop ? ARM::MVE_DLSTP_16 : ARM::MVE_WLSTP_16;
590   case ARM::MVE_VCTP32:
591     return IsDoLoop ? ARM::MVE_DLSTP_32 : ARM::MVE_WLSTP_32;
592   case ARM::MVE_VCTP64:
593     return IsDoLoop ? ARM::MVE_DLSTP_64 : ARM::MVE_WLSTP_64;
594   }
595   return 0;
596 }
597 
598 static inline
599 bool isVCTP(MachineInstr *MI) {
600   switch (MI->getOpcode()) {
601   default:
602     break;
603   case ARM::MVE_VCTP8:
604   case ARM::MVE_VCTP16:
605   case ARM::MVE_VCTP32:
606   case ARM::MVE_VCTP64:
607     return true;
608   }
609   return false;
610 }
611 
612 static inline
613 bool isLoopStart(MachineInstr &MI) {
614   return MI.getOpcode() == ARM::t2DoLoopStart ||
615          MI.getOpcode() == ARM::t2WhileLoopStart;
616 }
617 
618 static inline
619 bool isCondBranchOpcode(int Opc) {
620   return Opc == ARM::Bcc || Opc == ARM::tBcc || Opc == ARM::t2Bcc;
621 }
622 
623 static inline bool isJumpTableBranchOpcode(int Opc) {
624   return Opc == ARM::BR_JTr || Opc == ARM::BR_JTm_i12 ||
625          Opc == ARM::BR_JTm_rs || Opc == ARM::BR_JTadd || Opc == ARM::tBR_JTr ||
626          Opc == ARM::t2BR_JT;
627 }
628 
629 static inline
630 bool isIndirectBranchOpcode(int Opc) {
631   return Opc == ARM::BX || Opc == ARM::MOVPCRX || Opc == ARM::tBRIND;
632 }
633 
634 static inline bool isPopOpcode(int Opc) {
635   return Opc == ARM::tPOP_RET || Opc == ARM::LDMIA_RET ||
636          Opc == ARM::t2LDMIA_RET || Opc == ARM::tPOP || Opc == ARM::LDMIA_UPD ||
637          Opc == ARM::t2LDMIA_UPD || Opc == ARM::VLDMDIA_UPD;
638 }
639 
640 static inline bool isPushOpcode(int Opc) {
641   return Opc == ARM::tPUSH || Opc == ARM::t2STMDB_UPD ||
642          Opc == ARM::STMDB_UPD || Opc == ARM::VSTMDDB_UPD;
643 }
644 
645 /// isValidCoprocessorNumber - decide whether an explicit coprocessor
646 /// number is legal in generic instructions like CDP. The answer can
647 /// vary with the subtarget.
648 static inline bool isValidCoprocessorNumber(unsigned Num,
649                                             const FeatureBitset& featureBits) {
650   // Armv8-A disallows everything *other* than 111x (CP14 and CP15).
651   if (featureBits[ARM::HasV8Ops] && (Num & 0xE) != 0xE)
652     return false;
653 
654   // Armv7 disallows 101x (CP10 and CP11), which clash with VFP/NEON.
655   if (featureBits[ARM::HasV7Ops] && (Num & 0xE) == 0xA)
656     return false;
657 
658   // Armv8.1-M also disallows 100x (CP8,CP9) and 111x (CP14,CP15)
659   // which clash with MVE.
660   if (featureBits[ARM::HasV8_1MMainlineOps] &&
661       ((Num & 0xE) == 0x8 || (Num & 0xE) == 0xE))
662     return false;
663 
664   return true;
665 }
666 
667 /// getInstrPredicate - If instruction is predicated, returns its predicate
668 /// condition, otherwise returns AL. It also returns the condition code
669 /// register by reference.
670 ARMCC::CondCodes getInstrPredicate(const MachineInstr &MI, unsigned &PredReg);
671 
672 unsigned getMatchingCondBranchOpcode(unsigned Opc);
673 
674 /// Map pseudo instructions that imply an 'S' bit onto real opcodes. Whether
675 /// the instruction is encoded with an 'S' bit is determined by the optional
676 /// CPSR def operand.
677 unsigned convertAddSubFlagsOpcode(unsigned OldOpc);
678 
679 /// emitARMRegPlusImmediate / emitT2RegPlusImmediate - Emits a series of
680 /// instructions to materializea destreg = basereg + immediate in ARM / Thumb2
681 /// code.
682 void emitARMRegPlusImmediate(MachineBasicBlock &MBB,
683                              MachineBasicBlock::iterator &MBBI,
684                              const DebugLoc &dl, unsigned DestReg,
685                              unsigned BaseReg, int NumBytes,
686                              ARMCC::CondCodes Pred, unsigned PredReg,
687                              const ARMBaseInstrInfo &TII, unsigned MIFlags = 0);
688 
689 void emitT2RegPlusImmediate(MachineBasicBlock &MBB,
690                             MachineBasicBlock::iterator &MBBI,
691                             const DebugLoc &dl, unsigned DestReg,
692                             unsigned BaseReg, int NumBytes,
693                             ARMCC::CondCodes Pred, unsigned PredReg,
694                             const ARMBaseInstrInfo &TII, unsigned MIFlags = 0);
695 void emitThumbRegPlusImmediate(MachineBasicBlock &MBB,
696                                MachineBasicBlock::iterator &MBBI,
697                                const DebugLoc &dl, unsigned DestReg,
698                                unsigned BaseReg, int NumBytes,
699                                const TargetInstrInfo &TII,
700                                const ARMBaseRegisterInfo &MRI,
701                                unsigned MIFlags = 0);
702 
703 /// Tries to add registers to the reglist of a given base-updating
704 /// push/pop instruction to adjust the stack by an additional
705 /// NumBytes. This can save a few bytes per function in code-size, but
706 /// obviously generates more memory traffic. As such, it only takes
707 /// effect in functions being optimised for size.
708 bool tryFoldSPUpdateIntoPushPop(const ARMSubtarget &Subtarget,
709                                 MachineFunction &MF, MachineInstr *MI,
710                                 unsigned NumBytes);
711 
712 /// rewriteARMFrameIndex / rewriteT2FrameIndex -
713 /// Rewrite MI to access 'Offset' bytes from the FP. Return false if the
714 /// offset could not be handled directly in MI, and return the left-over
715 /// portion by reference.
716 bool rewriteARMFrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
717                           unsigned FrameReg, int &Offset,
718                           const ARMBaseInstrInfo &TII);
719 
720 bool rewriteT2FrameIndex(MachineInstr &MI, unsigned FrameRegIdx,
721                          unsigned FrameReg, int &Offset,
722                          const ARMBaseInstrInfo &TII,
723                          const TargetRegisterInfo *TRI);
724 
725 /// Return true if Reg is defd between From and To
726 bool registerDefinedBetween(unsigned Reg, MachineBasicBlock::iterator From,
727                             MachineBasicBlock::iterator To,
728                             const TargetRegisterInfo *TRI);
729 
730 /// Search backwards from a tBcc to find a tCMPi8 against 0, meaning
731 /// we can convert them to a tCBZ or tCBNZ. Return nullptr if not found.
732 MachineInstr *findCMPToFoldIntoCBZ(MachineInstr *Br,
733                                    const TargetRegisterInfo *TRI);
734 
735 void addUnpredicatedMveVpredNOp(MachineInstrBuilder &MIB);
736 void addUnpredicatedMveVpredROp(MachineInstrBuilder &MIB, unsigned DestReg);
737 
738 void addPredicatedMveVpredNOp(MachineInstrBuilder &MIB, unsigned Cond);
739 void addPredicatedMveVpredROp(MachineInstrBuilder &MIB, unsigned Cond,
740                               unsigned Inactive);
741 
742 /// Returns the number of instructions required to materialize the given
743 /// constant in a register, or 3 if a literal pool load is needed.
744 /// If ForCodesize is specified, an approximate cost in bytes is returned.
745 unsigned ConstantMaterializationCost(unsigned Val,
746                                      const ARMSubtarget *Subtarget,
747                                      bool ForCodesize = false);
748 
749 /// Returns true if Val1 has a lower Constant Materialization Cost than Val2.
750 /// Uses the cost from ConstantMaterializationCost, first with ForCodesize as
751 /// specified. If the scores are equal, return the comparison for !ForCodesize.
752 bool HasLowerConstantMaterializationCost(unsigned Val1, unsigned Val2,
753                                          const ARMSubtarget *Subtarget,
754                                          bool ForCodesize = false);
755 
756 } // end namespace llvm
757 
758 #endif // LLVM_LIB_TARGET_ARM_ARMBASEINSTRINFO_H
759