xref: /freebsd/contrib/llvm-project/llvm/lib/Target/PowerPC/PPCInstrInfo.h (revision e25152834cdf3b353892835a4f3b157e066a8ed4)
1 //===-- PPCInstrInfo.h - PowerPC 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 PowerPC implementation of the TargetInstrInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H
14 #define LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H
15 
16 #include "PPCRegisterInfo.h"
17 #include "llvm/CodeGen/TargetInstrInfo.h"
18 
19 #define GET_INSTRINFO_HEADER
20 #include "PPCGenInstrInfo.inc"
21 
22 namespace llvm {
23 
24 /// PPCII - This namespace holds all of the PowerPC target-specific
25 /// per-instruction flags.  These must match the corresponding definitions in
26 /// PPC.td and PPCInstrFormats.td.
27 namespace PPCII {
28 enum {
29   // PPC970 Instruction Flags.  These flags describe the characteristics of the
30   // PowerPC 970 (aka G5) dispatch groups and how they are formed out of
31   // raw machine instructions.
32 
33   /// PPC970_First - This instruction starts a new dispatch group, so it will
34   /// always be the first one in the group.
35   PPC970_First = 0x1,
36 
37   /// PPC970_Single - This instruction starts a new dispatch group and
38   /// terminates it, so it will be the sole instruction in the group.
39   PPC970_Single = 0x2,
40 
41   /// PPC970_Cracked - This instruction is cracked into two pieces, requiring
42   /// two dispatch pipes to be available to issue.
43   PPC970_Cracked = 0x4,
44 
45   /// PPC970_Mask/Shift - This is a bitmask that selects the pipeline type that
46   /// an instruction is issued to.
47   PPC970_Shift = 3,
48   PPC970_Mask = 0x07 << PPC970_Shift
49 };
50 enum PPC970_Unit {
51   /// These are the various PPC970 execution unit pipelines.  Each instruction
52   /// is one of these.
53   PPC970_Pseudo = 0 << PPC970_Shift,   // Pseudo instruction
54   PPC970_FXU    = 1 << PPC970_Shift,   // Fixed Point (aka Integer/ALU) Unit
55   PPC970_LSU    = 2 << PPC970_Shift,   // Load Store Unit
56   PPC970_FPU    = 3 << PPC970_Shift,   // Floating Point Unit
57   PPC970_CRU    = 4 << PPC970_Shift,   // Control Register Unit
58   PPC970_VALU   = 5 << PPC970_Shift,   // Vector ALU
59   PPC970_VPERM  = 6 << PPC970_Shift,   // Vector Permute Unit
60   PPC970_BRU    = 7 << PPC970_Shift    // Branch Unit
61 };
62 
63 enum {
64   /// Shift count to bypass PPC970 flags
65   NewDef_Shift = 6,
66 
67   /// This instruction is an X-Form memory operation.
68   XFormMemOp = 0x1 << NewDef_Shift,
69   /// This instruction is prefixed.
70   Prefixed = 0x1 << (NewDef_Shift+1)
71 };
72 } // end namespace PPCII
73 
74 // Instructions that have an immediate form might be convertible to that
75 // form if the correct input is a result of a load immediate. In order to
76 // know whether the transformation is special, we might need to know some
77 // of the details of the two forms.
78 struct ImmInstrInfo {
79   // Is the immediate field in the immediate form signed or unsigned?
80   uint64_t SignedImm : 1;
81   // Does the immediate need to be a multiple of some value?
82   uint64_t ImmMustBeMultipleOf : 5;
83   // Is R0/X0 treated specially by the original r+r instruction?
84   // If so, in which operand?
85   uint64_t ZeroIsSpecialOrig : 3;
86   // Is R0/X0 treated specially by the new r+i instruction?
87   // If so, in which operand?
88   uint64_t ZeroIsSpecialNew : 3;
89   // Is the operation commutative?
90   uint64_t IsCommutative : 1;
91   // The operand number to check for add-immediate def.
92   uint64_t OpNoForForwarding : 3;
93   // The operand number for the immediate.
94   uint64_t ImmOpNo : 3;
95   // The opcode of the new instruction.
96   uint64_t ImmOpcode : 16;
97   // The size of the immediate.
98   uint64_t ImmWidth : 5;
99   // The immediate should be truncated to N bits.
100   uint64_t TruncateImmTo : 5;
101   // Is the instruction summing the operand
102   uint64_t IsSummingOperands : 1;
103 };
104 
105 // Information required to convert an instruction to just a materialized
106 // immediate.
107 struct LoadImmediateInfo {
108   unsigned Imm : 16;
109   unsigned Is64Bit : 1;
110   unsigned SetCR : 1;
111 };
112 
113 // Index into the OpcodesForSpill array.
114 enum SpillOpcodeKey {
115   SOK_Int4Spill,
116   SOK_Int8Spill,
117   SOK_Float8Spill,
118   SOK_Float4Spill,
119   SOK_CRSpill,
120   SOK_CRBitSpill,
121   SOK_VRVectorSpill,
122   SOK_VSXVectorSpill,
123   SOK_VectorFloat8Spill,
124   SOK_VectorFloat4Spill,
125   SOK_VRSaveSpill,
126   SOK_QuadFloat8Spill,
127   SOK_QuadFloat4Spill,
128   SOK_QuadBitSpill,
129   SOK_SpillToVSR,
130   SOK_SPESpill,
131   SOK_LastOpcodeSpill // This must be last on the enum.
132 };
133 
134 // Define list of load and store spill opcodes.
135 #define Pwr8LoadOpcodes                                                        \
136   {                                                                            \
137     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
138         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXVD2X, PPC::LXSDX, PPC::LXSSPX,    \
139         PPC::RESTORE_VRSAVE, PPC::QVLFDX, PPC::QVLFSXs, PPC::QVLFDXb,          \
140         PPC::SPILLTOVSR_LD, PPC::EVLDD                                         \
141   }
142 
143 #define Pwr9LoadOpcodes                                                        \
144   {                                                                            \
145     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
146         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXV, PPC::DFLOADf64,                \
147         PPC::DFLOADf32, PPC::RESTORE_VRSAVE, PPC::QVLFDX, PPC::QVLFSXs,        \
148         PPC::QVLFDXb, PPC::SPILLTOVSR_LD                                       \
149   }
150 
151 #define Pwr8StoreOpcodes                                                       \
152   {                                                                            \
153     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
154         PPC::STVX, PPC::STXVD2X, PPC::STXSDX, PPC::STXSSPX, PPC::SPILL_VRSAVE, \
155         PPC::QVSTFDX, PPC::QVSTFSXs, PPC::QVSTFDXb, PPC::SPILLTOVSR_ST,        \
156         PPC::EVSTDD                                                            \
157   }
158 
159 #define Pwr9StoreOpcodes                                                       \
160   {                                                                            \
161     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
162         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
163         PPC::SPILL_VRSAVE, PPC::QVSTFDX, PPC::QVSTFSXs, PPC::QVSTFDXb,         \
164         PPC::SPILLTOVSR_ST                                                     \
165   }
166 
167 // Initialize arrays for load and store spill opcodes on supported subtargets.
168 #define StoreOpcodesForSpill                                                   \
169   { Pwr8StoreOpcodes, Pwr9StoreOpcodes }
170 #define LoadOpcodesForSpill                                                    \
171   { Pwr8LoadOpcodes, Pwr9LoadOpcodes }
172 
173 class PPCSubtarget;
174 class PPCInstrInfo : public PPCGenInstrInfo {
175   PPCSubtarget &Subtarget;
176   const PPCRegisterInfo RI;
177   const unsigned StoreSpillOpcodesArray[2][SOK_LastOpcodeSpill] =
178       StoreOpcodesForSpill;
179   const unsigned LoadSpillOpcodesArray[2][SOK_LastOpcodeSpill] =
180       LoadOpcodesForSpill;
181 
182   void StoreRegToStackSlot(MachineFunction &MF, unsigned SrcReg, bool isKill,
183                            int FrameIdx, const TargetRegisterClass *RC,
184                            SmallVectorImpl<MachineInstr *> &NewMIs) const;
185   void LoadRegFromStackSlot(MachineFunction &MF, const DebugLoc &DL,
186                             unsigned DestReg, int FrameIdx,
187                             const TargetRegisterClass *RC,
188                             SmallVectorImpl<MachineInstr *> &NewMIs) const;
189 
190   // Replace the instruction with single LI if possible. \p DefMI must be LI or
191   // LI8.
192   bool simplifyToLI(MachineInstr &MI, MachineInstr &DefMI,
193                     unsigned OpNoForForwarding, MachineInstr **KilledDef) const;
194   // If the inst is imm-form and its register operand is produced by a ADDI, put
195   // the imm into the inst directly and remove the ADDI if possible.
196   bool transformToNewImmFormFedByAdd(MachineInstr &MI, MachineInstr &DefMI,
197                                      unsigned OpNoForForwarding) const;
198   // If the inst is x-form and has imm-form and one of its operand is produced
199   // by a LI, put the imm into the inst directly and remove the LI if possible.
200   bool transformToImmFormFedByLI(MachineInstr &MI, const ImmInstrInfo &III,
201                                  unsigned ConstantOpNo,
202                                  MachineInstr &DefMI) const;
203   // If the inst is x-form and has imm-form and one of its operand is produced
204   // by an add-immediate, try to transform it when possible.
205   bool transformToImmFormFedByAdd(MachineInstr &MI, const ImmInstrInfo &III,
206                                   unsigned ConstantOpNo, MachineInstr &DefMI,
207                                   bool KillDefMI) const;
208   // Try to find that, if the instruction 'MI' contains any operand that
209   // could be forwarded from some inst that feeds it. If yes, return the
210   // Def of that operand. And OpNoForForwarding is the operand index in
211   // the 'MI' for that 'Def'. If we see another use of this Def between
212   // the Def and the MI, SeenIntermediateUse becomes 'true'.
213   MachineInstr *getForwardingDefMI(MachineInstr &MI,
214                                    unsigned &OpNoForForwarding,
215                                    bool &SeenIntermediateUse) const;
216 
217   // Can the user MI have it's source at index \p OpNoForForwarding
218   // forwarded from an add-immediate that feeds it?
219   bool isUseMIElgibleForForwarding(MachineInstr &MI, const ImmInstrInfo &III,
220                                    unsigned OpNoForForwarding) const;
221   bool isDefMIElgibleForForwarding(MachineInstr &DefMI,
222                                    const ImmInstrInfo &III,
223                                    MachineOperand *&ImmMO,
224                                    MachineOperand *&RegMO) const;
225   bool isImmElgibleForForwarding(const MachineOperand &ImmMO,
226                                  const MachineInstr &DefMI,
227                                  const ImmInstrInfo &III,
228                                  int64_t &Imm,
229                                  int64_t BaseImm = 0) const;
230   bool isRegElgibleForForwarding(const MachineOperand &RegMO,
231                                  const MachineInstr &DefMI,
232                                  const MachineInstr &MI, bool KillDefMI,
233                                  bool &IsFwdFeederRegKilled) const;
234   unsigned getSpillTarget() const;
235   const unsigned *getStoreOpcodesForSpillArray() const;
236   const unsigned *getLoadOpcodesForSpillArray() const;
237   int16_t getFMAOpIdxInfo(unsigned Opcode) const;
238   void reassociateFMA(MachineInstr &Root, MachineCombinerPattern Pattern,
239                       SmallVectorImpl<MachineInstr *> &InsInstrs,
240                       SmallVectorImpl<MachineInstr *> &DelInstrs,
241                       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const;
242   virtual void anchor();
243 
244 protected:
245   /// Commutes the operands in the given instruction.
246   /// The commutable operands are specified by their indices OpIdx1 and OpIdx2.
247   ///
248   /// Do not call this method for a non-commutable instruction or for
249   /// non-commutable pair of operand indices OpIdx1 and OpIdx2.
250   /// Even though the instruction is commutable, the method may still
251   /// fail to commute the operands, null pointer is returned in such cases.
252   ///
253   /// For example, we can commute rlwimi instructions, but only if the
254   /// rotate amt is zero.  We also have to munge the immediates a bit.
255   MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
256                                        unsigned OpIdx1,
257                                        unsigned OpIdx2) const override;
258 
259 public:
260   explicit PPCInstrInfo(PPCSubtarget &STI);
261 
262   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
263   /// such, whenever a client has an instance of instruction info, it should
264   /// always be able to get register info as well (through this method).
265   ///
266   const PPCRegisterInfo &getRegisterInfo() const { return RI; }
267 
268   bool isXFormMemOp(unsigned Opcode) const {
269     return get(Opcode).TSFlags & PPCII::XFormMemOp;
270   }
271   bool isPrefixed(unsigned Opcode) const {
272     return get(Opcode).TSFlags & PPCII::Prefixed;
273   }
274 
275   static bool isSameClassPhysRegCopy(unsigned Opcode) {
276     unsigned CopyOpcodes[] =
277       { PPC::OR, PPC::OR8, PPC::FMR, PPC::VOR, PPC::XXLOR, PPC::XXLORf,
278         PPC::XSCPSGNDP, PPC::MCRF, PPC::QVFMR, PPC::QVFMRs, PPC::QVFMRb,
279         PPC::CROR, PPC::EVOR, -1U };
280     for (int i = 0; CopyOpcodes[i] != -1U; i++)
281       if (Opcode == CopyOpcodes[i])
282         return true;
283     return false;
284   }
285 
286   ScheduleHazardRecognizer *
287   CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
288                                const ScheduleDAG *DAG) const override;
289   ScheduleHazardRecognizer *
290   CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
291                                      const ScheduleDAG *DAG) const override;
292 
293   unsigned getInstrLatency(const InstrItineraryData *ItinData,
294                            const MachineInstr &MI,
295                            unsigned *PredCost = nullptr) const override;
296 
297   int getOperandLatency(const InstrItineraryData *ItinData,
298                         const MachineInstr &DefMI, unsigned DefIdx,
299                         const MachineInstr &UseMI,
300                         unsigned UseIdx) const override;
301   int getOperandLatency(const InstrItineraryData *ItinData,
302                         SDNode *DefNode, unsigned DefIdx,
303                         SDNode *UseNode, unsigned UseIdx) const override {
304     return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
305                                               UseNode, UseIdx);
306   }
307 
308   bool hasLowDefLatency(const TargetSchedModel &SchedModel,
309                         const MachineInstr &DefMI,
310                         unsigned DefIdx) const override {
311     // Machine LICM should hoist all instructions in low-register-pressure
312     // situations; none are sufficiently free to justify leaving in a loop
313     // body.
314     return false;
315   }
316 
317   bool useMachineCombiner() const override {
318     return true;
319   }
320 
321   /// When getMachineCombinerPatterns() finds patterns, this function generates
322   /// the instructions that could replace the original code sequence
323   void genAlternativeCodeSequence(
324       MachineInstr &Root, MachineCombinerPattern Pattern,
325       SmallVectorImpl<MachineInstr *> &InsInstrs,
326       SmallVectorImpl<MachineInstr *> &DelInstrs,
327       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
328 
329   /// Return true when there is potentially a faster code sequence for a fma
330   /// chain ending in \p Root. All potential patterns are output in the \p
331   /// P array.
332   bool getFMAPatterns(MachineInstr &Root,
333                       SmallVectorImpl<MachineCombinerPattern> &P) const;
334 
335   /// Return true when there is potentially a faster code sequence
336   /// for an instruction chain ending in <Root>. All potential patterns are
337   /// output in the <Pattern> array.
338   bool getMachineCombinerPatterns(
339       MachineInstr &Root,
340       SmallVectorImpl<MachineCombinerPattern> &P) const override;
341 
342   bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
343 
344   /// On PowerPC, we try to reassociate FMA chain which will increase
345   /// instruction size. Set extension resource length limit to 1 for edge case.
346   /// Resource Length is calculated by scaled resource usage in getCycles().
347   /// Because of the division in getCycles(), it returns different cycles due to
348   /// legacy scaled resource usage. So new resource length may be same with
349   /// legacy or 1 bigger than legacy.
350   /// We need to execlude the 1 bigger case even the resource length is not
351   /// perserved for more FMA chain reassociations on PowerPC.
352   int getExtendResourceLenLimit() const override { return 1; }
353 
354   void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
355                              MachineInstr &NewMI1,
356                              MachineInstr &NewMI2) const override;
357 
358   void setSpecialOperandAttr(MachineInstr &MI, uint16_t Flags) const override;
359 
360   bool isCoalescableExtInstr(const MachineInstr &MI,
361                              Register &SrcReg, Register &DstReg,
362                              unsigned &SubIdx) const override;
363   unsigned isLoadFromStackSlot(const MachineInstr &MI,
364                                int &FrameIndex) const override;
365   bool isReallyTriviallyReMaterializable(const MachineInstr &MI,
366                                          AAResults *AA) const override;
367   unsigned isStoreToStackSlot(const MachineInstr &MI,
368                               int &FrameIndex) const override;
369 
370   bool findCommutedOpIndices(const MachineInstr &MI, unsigned &SrcOpIdx1,
371                              unsigned &SrcOpIdx2) const override;
372 
373   void insertNoop(MachineBasicBlock &MBB,
374                   MachineBasicBlock::iterator MI) const override;
375 
376 
377   // Branch analysis.
378   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
379                      MachineBasicBlock *&FBB,
380                      SmallVectorImpl<MachineOperand> &Cond,
381                      bool AllowModify) const override;
382   unsigned removeBranch(MachineBasicBlock &MBB,
383                         int *BytesRemoved = nullptr) const override;
384   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
385                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
386                         const DebugLoc &DL,
387                         int *BytesAdded = nullptr) const override;
388 
389   // Select analysis.
390   bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
391                        Register, Register, Register, int &, int &,
392                        int &) const override;
393   void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
394                     const DebugLoc &DL, Register DstReg,
395                     ArrayRef<MachineOperand> Cond, Register TrueReg,
396                     Register FalseReg) const override;
397 
398   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
399                    const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
400                    bool KillSrc) const override;
401 
402   void storeRegToStackSlot(MachineBasicBlock &MBB,
403                            MachineBasicBlock::iterator MBBI,
404                            Register SrcReg, bool isKill, int FrameIndex,
405                            const TargetRegisterClass *RC,
406                            const TargetRegisterInfo *TRI) const override;
407 
408   // Emits a register spill without updating the register class for vector
409   // registers. This ensures that when we spill a vector register the
410   // element order in the register is the same as it was in memory.
411   void storeRegToStackSlotNoUpd(MachineBasicBlock &MBB,
412                                 MachineBasicBlock::iterator MBBI,
413                                 unsigned SrcReg, bool isKill, int FrameIndex,
414                                 const TargetRegisterClass *RC,
415                                 const TargetRegisterInfo *TRI) const;
416 
417   void loadRegFromStackSlot(MachineBasicBlock &MBB,
418                             MachineBasicBlock::iterator MBBI,
419                             Register DestReg, int FrameIndex,
420                             const TargetRegisterClass *RC,
421                             const TargetRegisterInfo *TRI) const override;
422 
423   // Emits a register reload without updating the register class for vector
424   // registers. This ensures that when we reload a vector register the
425   // element order in the register is the same as it was in memory.
426   void loadRegFromStackSlotNoUpd(MachineBasicBlock &MBB,
427                                  MachineBasicBlock::iterator MBBI,
428                                  unsigned DestReg, int FrameIndex,
429                                  const TargetRegisterClass *RC,
430                                  const TargetRegisterInfo *TRI) const;
431 
432   unsigned getStoreOpcodeForSpill(const TargetRegisterClass *RC) const;
433 
434   unsigned getLoadOpcodeForSpill(const TargetRegisterClass *RC) const;
435 
436   bool
437   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
438 
439   bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, Register Reg,
440                      MachineRegisterInfo *MRI) const override;
441 
442   bool onlyFoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
443                          Register Reg) const;
444 
445   // If conversion by predication (only supported by some branch instructions).
446   // All of the profitability checks always return true; it is always
447   // profitable to use the predicated branches.
448   bool isProfitableToIfCvt(MachineBasicBlock &MBB,
449                           unsigned NumCycles, unsigned ExtraPredCycles,
450                           BranchProbability Probability) const override {
451     return true;
452   }
453 
454   bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
455                            unsigned NumT, unsigned ExtraT,
456                            MachineBasicBlock &FMBB,
457                            unsigned NumF, unsigned ExtraF,
458                            BranchProbability Probability) const override;
459 
460   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
461                                  BranchProbability Probability) const override {
462     return true;
463   }
464 
465   bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
466                                  MachineBasicBlock &FMBB) const override {
467     return false;
468   }
469 
470   // Predication support.
471   bool isPredicated(const MachineInstr &MI) const override;
472 
473   bool PredicateInstruction(MachineInstr &MI,
474                             ArrayRef<MachineOperand> Pred) const override;
475 
476   bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
477                          ArrayRef<MachineOperand> Pred2) const override;
478 
479   bool DefinesPredicate(MachineInstr &MI,
480                         std::vector<MachineOperand> &Pred) const override;
481 
482   // Comparison optimization.
483 
484   bool analyzeCompare(const MachineInstr &MI, Register &SrcReg,
485                       Register &SrcReg2, int &Mask, int &Value) const override;
486 
487   bool optimizeCompareInstr(MachineInstr &CmpInstr, Register SrcReg,
488                             Register SrcReg2, int Mask, int Value,
489                             const MachineRegisterInfo *MRI) const override;
490 
491 
492   /// Return true if get the base operand, byte offset of an instruction and
493   /// the memory width. Width is the size of memory that is being
494   /// loaded/stored (e.g. 1, 2, 4, 8).
495   bool getMemOperandWithOffsetWidth(const MachineInstr &LdSt,
496                                     const MachineOperand *&BaseOp,
497                                     int64_t &Offset, unsigned &Width,
498                                     const TargetRegisterInfo *TRI) const;
499 
500   /// Return true if two MIs access different memory addresses and false
501   /// otherwise
502   bool
503   areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
504                                   const MachineInstr &MIb) const override;
505 
506   /// GetInstSize - Return the number of bytes of code the specified
507   /// instruction may be.  This returns the maximum number of bytes.
508   ///
509   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
510 
511   void getNoop(MCInst &NopInst) const override;
512 
513   std::pair<unsigned, unsigned>
514   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
515 
516   ArrayRef<std::pair<unsigned, const char *>>
517   getSerializableDirectMachineOperandTargetFlags() const override;
518 
519   ArrayRef<std::pair<unsigned, const char *>>
520   getSerializableBitmaskMachineOperandTargetFlags() const override;
521 
522   // Expand VSX Memory Pseudo instruction to either a VSX or a FP instruction.
523   bool expandVSXMemPseudo(MachineInstr &MI) const;
524 
525   // Lower pseudo instructions after register allocation.
526   bool expandPostRAPseudo(MachineInstr &MI) const override;
527 
528   static bool isVFRegister(unsigned Reg) {
529     return Reg >= PPC::VF0 && Reg <= PPC::VF31;
530   }
531   static bool isVRRegister(unsigned Reg) {
532     return Reg >= PPC::V0 && Reg <= PPC::V31;
533   }
534   const TargetRegisterClass *updatedRC(const TargetRegisterClass *RC) const;
535   static int getRecordFormOpcode(unsigned Opcode);
536 
537   bool isTOCSaveMI(const MachineInstr &MI) const;
538 
539   bool isSignOrZeroExtended(const MachineInstr &MI, bool SignExt,
540                             const unsigned PhiDepth) const;
541 
542   /// Return true if the output of the instruction is always a sign-extended,
543   /// i.e. 0 to 31-th bits are same as 32-th bit.
544   bool isSignExtended(const MachineInstr &MI, const unsigned depth = 0) const {
545     return isSignOrZeroExtended(MI, true, depth);
546   }
547 
548   /// Return true if the output of the instruction is always zero-extended,
549   /// i.e. 0 to 31-th bits are all zeros
550   bool isZeroExtended(const MachineInstr &MI, const unsigned depth = 0) const {
551    return isSignOrZeroExtended(MI, false, depth);
552   }
553 
554   bool convertToImmediateForm(MachineInstr &MI,
555                               MachineInstr **KilledDef = nullptr) const;
556   bool foldFrameOffset(MachineInstr &MI) const;
557   bool isADDIInstrEligibleForFolding(MachineInstr &ADDIMI, int64_t &Imm) const;
558   bool isADDInstrEligibleForFolding(MachineInstr &ADDMI) const;
559   bool isImmInstrEligibleForFolding(MachineInstr &MI, unsigned &BaseReg,
560                                     unsigned &XFormOpcode,
561                                     int64_t &OffsetOfImmInstr,
562                                     ImmInstrInfo &III) const;
563   bool isValidToBeChangedReg(MachineInstr *ADDMI, unsigned Index,
564                              MachineInstr *&ADDIMI, int64_t &OffsetAddi,
565                              int64_t OffsetImm) const;
566 
567   /// Fixup killed/dead flag for register \p RegNo between instructions [\p
568   /// StartMI, \p EndMI]. Some pre-RA or post-RA transformations may violate
569   /// register killed/dead flags semantics, this function can be called to fix
570   /// up. Before calling this function,
571   /// 1. Ensure that \p RegNo liveness is killed after instruction \p EndMI.
572   /// 2. Ensure that there is no new definition between (\p StartMI, \p EndMI)
573   ///    and possible definition for \p RegNo is \p StartMI or \p EndMI. For
574   ///    pre-RA cases, definition may be \p StartMI through COPY, \p StartMI
575   ///    will be adjust to true definition.
576   /// 3. We can do accurate fixup for the case when all instructions between
577   ///    [\p StartMI, \p EndMI] are in same basic block.
578   /// 4. For the case when \p StartMI and \p EndMI are not in same basic block,
579   ///    we conservatively clear kill flag for all uses of \p RegNo for pre-RA
580   ///    and for post-RA, we give an assertion as without reaching definition
581   ///    analysis post-RA, \p StartMI and \p EndMI are hard to keep right.
582   void fixupIsDeadOrKill(MachineInstr *StartMI, MachineInstr *EndMI,
583                          unsigned RegNo) const;
584   void replaceInstrWithLI(MachineInstr &MI, const LoadImmediateInfo &LII) const;
585   void replaceInstrOperandWithImm(MachineInstr &MI, unsigned OpNo,
586                                   int64_t Imm) const;
587 
588   bool instrHasImmForm(unsigned Opc, bool IsVFReg, ImmInstrInfo &III,
589                        bool PostRA) const;
590 
591   // In PostRA phase, try to find instruction defines \p Reg before \p MI.
592   // \p SeenIntermediate is set to true if uses between DefMI and \p MI exist.
593   MachineInstr *getDefMIPostRA(unsigned Reg, MachineInstr &MI,
594                                bool &SeenIntermediateUse) const;
595 
596   /// getRegNumForOperand - some operands use different numbering schemes
597   /// for the same registers. For example, a VSX instruction may have any of
598   /// vs0-vs63 allocated whereas an Altivec instruction could only have
599   /// vs32-vs63 allocated (numbered as v0-v31). This function returns the actual
600   /// register number needed for the opcode/operand number combination.
601   /// The operand number argument will be useful when we need to extend this
602   /// to instructions that use both Altivec and VSX numbering (for different
603   /// operands).
604   static unsigned getRegNumForOperand(const MCInstrDesc &Desc, unsigned Reg,
605                                       unsigned OpNo) {
606     int16_t regClass = Desc.OpInfo[OpNo].RegClass;
607     switch (regClass) {
608       // We store F0-F31, VF0-VF31 in MCOperand and it should be F0-F31,
609       // VSX32-VSX63 during encoding/disassembling
610       case PPC::VSSRCRegClassID:
611       case PPC::VSFRCRegClassID:
612         if (isVFRegister(Reg))
613           return PPC::VSX32 + (Reg - PPC::VF0);
614         break;
615       // We store VSL0-VSL31, V0-V31 in MCOperand and it should be VSL0-VSL31,
616       // VSX32-VSX63 during encoding/disassembling
617       case PPC::VSRCRegClassID:
618         if (isVRRegister(Reg))
619           return PPC::VSX32 + (Reg - PPC::V0);
620         break;
621       // Other RegClass doesn't need mapping
622       default:
623         break;
624     }
625     return Reg;
626   }
627 
628   /// Check \p Opcode is BDNZ (Decrement CTR and branch if it is still nonzero).
629   bool isBDNZ(unsigned Opcode) const;
630 
631   /// Find the hardware loop instruction used to set-up the specified loop.
632   /// On PPC, we have two instructions used to set-up the hardware loop
633   /// (MTCTRloop, MTCTR8loop) with corresponding endloop (BDNZ, BDNZ8)
634   /// instructions to indicate the end of a loop.
635   MachineInstr *
636   findLoopInstr(MachineBasicBlock &PreHeader,
637                 SmallPtrSet<MachineBasicBlock *, 8> &Visited) const;
638 
639   /// Analyze loop L, which must be a single-basic-block loop, and if the
640   /// conditions can be understood enough produce a PipelinerLoopInfo object.
641   std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
642   analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const override;
643 };
644 
645 }
646 
647 #endif
648