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_SpillToVSR,
126   SOK_PairedVecSpill,
127   SOK_AccumulatorSpill,
128   SOK_UAccumulatorSpill,
129   SOK_SPESpill,
130   SOK_LastOpcodeSpill // This must be last on the enum.
131 };
132 
133 // Define list of load and store spill opcodes.
134 #define NoInstr PPC::INSTRUCTION_LIST_END
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::SPILLTOVSR_LD, NoInstr, NoInstr, NoInstr, PPC::EVLDD              \
140   }
141 
142 #define Pwr9LoadOpcodes                                                        \
143   {                                                                            \
144     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
145         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXV, PPC::DFLOADf64,                \
146         PPC::DFLOADf32, PPC::SPILLTOVSR_LD, NoInstr, NoInstr, NoInstr, NoInstr \
147   }
148 
149 #define Pwr10LoadOpcodes                                                       \
150   {                                                                            \
151     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
152         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXV, PPC::DFLOADf64,                \
153         PPC::DFLOADf32, PPC::SPILLTOVSR_LD, PPC::LXVP, PPC::RESTORE_ACC,       \
154         PPC::RESTORE_UACC, NoInstr                                             \
155   }
156 
157 #define Pwr8StoreOpcodes                                                       \
158   {                                                                            \
159     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
160         PPC::STVX, PPC::STXVD2X, PPC::STXSDX, PPC::STXSSPX,                    \
161         PPC::SPILLTOVSR_ST, NoInstr, NoInstr, NoInstr, PPC::EVSTDD             \
162   }
163 
164 #define Pwr9StoreOpcodes                                                       \
165   {                                                                            \
166     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
167         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
168         PPC::SPILLTOVSR_ST, NoInstr, NoInstr, NoInstr, NoInstr                 \
169   }
170 
171 #define Pwr10StoreOpcodes                                                      \
172   {                                                                            \
173     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
174         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
175         PPC::SPILLTOVSR_ST, PPC::STXVP, PPC::SPILL_ACC, PPC::SPILL_UACC,       \
176         NoInstr                                                                \
177   }
178 
179 // Initialize arrays for load and store spill opcodes on supported subtargets.
180 #define StoreOpcodesForSpill                                                   \
181   { Pwr8StoreOpcodes, Pwr9StoreOpcodes, Pwr10StoreOpcodes }
182 #define LoadOpcodesForSpill                                                    \
183   { Pwr8LoadOpcodes, Pwr9LoadOpcodes, Pwr10LoadOpcodes }
184 
185 class PPCSubtarget;
186 class PPCInstrInfo : public PPCGenInstrInfo {
187   PPCSubtarget &Subtarget;
188   const PPCRegisterInfo RI;
189   const unsigned StoreSpillOpcodesArray[3][SOK_LastOpcodeSpill] =
190       StoreOpcodesForSpill;
191   const unsigned LoadSpillOpcodesArray[3][SOK_LastOpcodeSpill] =
192       LoadOpcodesForSpill;
193 
194   void StoreRegToStackSlot(MachineFunction &MF, unsigned SrcReg, bool isKill,
195                            int FrameIdx, const TargetRegisterClass *RC,
196                            SmallVectorImpl<MachineInstr *> &NewMIs) const;
197   void LoadRegFromStackSlot(MachineFunction &MF, const DebugLoc &DL,
198                             unsigned DestReg, int FrameIdx,
199                             const TargetRegisterClass *RC,
200                             SmallVectorImpl<MachineInstr *> &NewMIs) const;
201 
202   // Replace the instruction with single LI if possible. \p DefMI must be LI or
203   // LI8.
204   bool simplifyToLI(MachineInstr &MI, MachineInstr &DefMI,
205                     unsigned OpNoForForwarding, MachineInstr **KilledDef) const;
206   // If the inst is imm-form and its register operand is produced by a ADDI, put
207   // the imm into the inst directly and remove the ADDI if possible.
208   bool transformToNewImmFormFedByAdd(MachineInstr &MI, MachineInstr &DefMI,
209                                      unsigned OpNoForForwarding) const;
210   // If the inst is x-form and has imm-form and one of its operand is produced
211   // by a LI, put the imm into the inst directly and remove the LI if possible.
212   bool transformToImmFormFedByLI(MachineInstr &MI, const ImmInstrInfo &III,
213                                  unsigned ConstantOpNo,
214                                  MachineInstr &DefMI) const;
215   // If the inst is x-form and has imm-form and one of its operand is produced
216   // by an add-immediate, try to transform it when possible.
217   bool transformToImmFormFedByAdd(MachineInstr &MI, const ImmInstrInfo &III,
218                                   unsigned ConstantOpNo, MachineInstr &DefMI,
219                                   bool KillDefMI) const;
220   // Try to find that, if the instruction 'MI' contains any operand that
221   // could be forwarded from some inst that feeds it. If yes, return the
222   // Def of that operand. And OpNoForForwarding is the operand index in
223   // the 'MI' for that 'Def'. If we see another use of this Def between
224   // the Def and the MI, SeenIntermediateUse becomes 'true'.
225   MachineInstr *getForwardingDefMI(MachineInstr &MI,
226                                    unsigned &OpNoForForwarding,
227                                    bool &SeenIntermediateUse) const;
228 
229   // Can the user MI have it's source at index \p OpNoForForwarding
230   // forwarded from an add-immediate that feeds it?
231   bool isUseMIElgibleForForwarding(MachineInstr &MI, const ImmInstrInfo &III,
232                                    unsigned OpNoForForwarding) const;
233   bool isDefMIElgibleForForwarding(MachineInstr &DefMI,
234                                    const ImmInstrInfo &III,
235                                    MachineOperand *&ImmMO,
236                                    MachineOperand *&RegMO) const;
237   bool isImmElgibleForForwarding(const MachineOperand &ImmMO,
238                                  const MachineInstr &DefMI,
239                                  const ImmInstrInfo &III,
240                                  int64_t &Imm,
241                                  int64_t BaseImm = 0) const;
242   bool isRegElgibleForForwarding(const MachineOperand &RegMO,
243                                  const MachineInstr &DefMI,
244                                  const MachineInstr &MI, bool KillDefMI,
245                                  bool &IsFwdFeederRegKilled) const;
246   unsigned getSpillTarget() const;
247   const unsigned *getStoreOpcodesForSpillArray() const;
248   const unsigned *getLoadOpcodesForSpillArray() const;
249   unsigned getSpillIndex(const TargetRegisterClass *RC) const;
250   int16_t getFMAOpIdxInfo(unsigned Opcode) const;
251   void reassociateFMA(MachineInstr &Root, MachineCombinerPattern Pattern,
252                       SmallVectorImpl<MachineInstr *> &InsInstrs,
253                       SmallVectorImpl<MachineInstr *> &DelInstrs,
254                       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const;
255   bool isLoadFromConstantPool(MachineInstr *I) const;
256   Register
257   generateLoadForNewConst(unsigned Idx, MachineInstr *MI, Type *Ty,
258                           SmallVectorImpl<MachineInstr *> &InsInstrs) const;
259   const Constant *getConstantFromConstantPool(MachineInstr *I) const;
260   virtual void anchor();
261 
262 protected:
263   /// Commutes the operands in the given instruction.
264   /// The commutable operands are specified by their indices OpIdx1 and OpIdx2.
265   ///
266   /// Do not call this method for a non-commutable instruction or for
267   /// non-commutable pair of operand indices OpIdx1 and OpIdx2.
268   /// Even though the instruction is commutable, the method may still
269   /// fail to commute the operands, null pointer is returned in such cases.
270   ///
271   /// For example, we can commute rlwimi instructions, but only if the
272   /// rotate amt is zero.  We also have to munge the immediates a bit.
273   MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
274                                        unsigned OpIdx1,
275                                        unsigned OpIdx2) const override;
276 
277 public:
278   explicit PPCInstrInfo(PPCSubtarget &STI);
279 
280   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
281   /// such, whenever a client has an instance of instruction info, it should
282   /// always be able to get register info as well (through this method).
283   ///
getRegisterInfo()284   const PPCRegisterInfo &getRegisterInfo() const { return RI; }
285 
isXFormMemOp(unsigned Opcode)286   bool isXFormMemOp(unsigned Opcode) const {
287     return get(Opcode).TSFlags & PPCII::XFormMemOp;
288   }
isPrefixed(unsigned Opcode)289   bool isPrefixed(unsigned Opcode) const {
290     return get(Opcode).TSFlags & PPCII::Prefixed;
291   }
292 
isSameClassPhysRegCopy(unsigned Opcode)293   static bool isSameClassPhysRegCopy(unsigned Opcode) {
294     unsigned CopyOpcodes[] = {PPC::OR,        PPC::OR8,   PPC::FMR,
295                               PPC::VOR,       PPC::XXLOR, PPC::XXLORf,
296                               PPC::XSCPSGNDP, PPC::MCRF,  PPC::CROR,
297                               PPC::EVOR,      -1U};
298     for (int i = 0; CopyOpcodes[i] != -1U; i++)
299       if (Opcode == CopyOpcodes[i])
300         return true;
301     return false;
302   }
303 
304   ScheduleHazardRecognizer *
305   CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
306                                const ScheduleDAG *DAG) const override;
307   ScheduleHazardRecognizer *
308   CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
309                                      const ScheduleDAG *DAG) const override;
310 
311   unsigned getInstrLatency(const InstrItineraryData *ItinData,
312                            const MachineInstr &MI,
313                            unsigned *PredCost = nullptr) const override;
314 
315   int getOperandLatency(const InstrItineraryData *ItinData,
316                         const MachineInstr &DefMI, unsigned DefIdx,
317                         const MachineInstr &UseMI,
318                         unsigned UseIdx) const override;
getOperandLatency(const InstrItineraryData * ItinData,SDNode * DefNode,unsigned DefIdx,SDNode * UseNode,unsigned UseIdx)319   int getOperandLatency(const InstrItineraryData *ItinData,
320                         SDNode *DefNode, unsigned DefIdx,
321                         SDNode *UseNode, unsigned UseIdx) const override {
322     return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
323                                               UseNode, UseIdx);
324   }
325 
hasLowDefLatency(const TargetSchedModel & SchedModel,const MachineInstr & DefMI,unsigned DefIdx)326   bool hasLowDefLatency(const TargetSchedModel &SchedModel,
327                         const MachineInstr &DefMI,
328                         unsigned DefIdx) const override {
329     // Machine LICM should hoist all instructions in low-register-pressure
330     // situations; none are sufficiently free to justify leaving in a loop
331     // body.
332     return false;
333   }
334 
useMachineCombiner()335   bool useMachineCombiner() const override {
336     return true;
337   }
338 
339   /// When getMachineCombinerPatterns() finds patterns, this function generates
340   /// the instructions that could replace the original code sequence
341   void genAlternativeCodeSequence(
342       MachineInstr &Root, MachineCombinerPattern Pattern,
343       SmallVectorImpl<MachineInstr *> &InsInstrs,
344       SmallVectorImpl<MachineInstr *> &DelInstrs,
345       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
346 
347   /// Return true when there is potentially a faster code sequence for a fma
348   /// chain ending in \p Root. All potential patterns are output in the \p
349   /// P array.
350   bool getFMAPatterns(MachineInstr &Root,
351                       SmallVectorImpl<MachineCombinerPattern> &P,
352                       bool DoRegPressureReduce) const;
353 
354   /// Return true when there is potentially a faster code sequence
355   /// for an instruction chain ending in <Root>. All potential patterns are
356   /// output in the <Pattern> array.
357   bool getMachineCombinerPatterns(MachineInstr &Root,
358                                   SmallVectorImpl<MachineCombinerPattern> &P,
359                                   bool DoRegPressureReduce) const override;
360 
361   /// On PowerPC, we leverage machine combiner pass to reduce register pressure
362   /// when the register pressure is high for one BB.
363   /// Return true if register pressure for \p MBB is high and ABI is supported
364   /// to reduce register pressure. Otherwise return false.
365   bool
366   shouldReduceRegisterPressure(MachineBasicBlock *MBB,
367                                RegisterClassInfo *RegClassInfo) const override;
368 
369   /// Fixup the placeholders we put in genAlternativeCodeSequence() for
370   /// MachineCombiner.
371   void
372   finalizeInsInstrs(MachineInstr &Root, MachineCombinerPattern &P,
373                     SmallVectorImpl<MachineInstr *> &InsInstrs) const override;
374 
375   bool isAssociativeAndCommutative(const MachineInstr &Inst) const override;
376 
377   /// On PowerPC, we try to reassociate FMA chain which will increase
378   /// instruction size. Set extension resource length limit to 1 for edge case.
379   /// Resource Length is calculated by scaled resource usage in getCycles().
380   /// Because of the division in getCycles(), it returns different cycles due to
381   /// legacy scaled resource usage. So new resource length may be same with
382   /// legacy or 1 bigger than legacy.
383   /// We need to execlude the 1 bigger case even the resource length is not
384   /// perserved for more FMA chain reassociations on PowerPC.
getExtendResourceLenLimit()385   int getExtendResourceLenLimit() const override { return 1; }
386 
387   void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
388                              MachineInstr &NewMI1,
389                              MachineInstr &NewMI2) const override;
390 
391   void setSpecialOperandAttr(MachineInstr &MI, uint16_t Flags) const override;
392 
393   bool isCoalescableExtInstr(const MachineInstr &MI,
394                              Register &SrcReg, Register &DstReg,
395                              unsigned &SubIdx) const override;
396   unsigned isLoadFromStackSlot(const MachineInstr &MI,
397                                int &FrameIndex) const override;
398   bool isReallyTriviallyReMaterializable(const MachineInstr &MI,
399                                          AAResults *AA) const override;
400   unsigned isStoreToStackSlot(const MachineInstr &MI,
401                               int &FrameIndex) const override;
402 
403   bool findCommutedOpIndices(const MachineInstr &MI, unsigned &SrcOpIdx1,
404                              unsigned &SrcOpIdx2) const override;
405 
406   void insertNoop(MachineBasicBlock &MBB,
407                   MachineBasicBlock::iterator MI) const override;
408 
409 
410   // Branch analysis.
411   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
412                      MachineBasicBlock *&FBB,
413                      SmallVectorImpl<MachineOperand> &Cond,
414                      bool AllowModify) const override;
415   unsigned removeBranch(MachineBasicBlock &MBB,
416                         int *BytesRemoved = nullptr) const override;
417   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
418                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
419                         const DebugLoc &DL,
420                         int *BytesAdded = nullptr) const override;
421 
422   // Select analysis.
423   bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
424                        Register, Register, Register, int &, int &,
425                        int &) const override;
426   void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
427                     const DebugLoc &DL, Register DstReg,
428                     ArrayRef<MachineOperand> Cond, Register TrueReg,
429                     Register FalseReg) const override;
430 
431   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
432                    const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
433                    bool KillSrc) const override;
434 
435   void storeRegToStackSlot(MachineBasicBlock &MBB,
436                            MachineBasicBlock::iterator MBBI,
437                            Register SrcReg, bool isKill, int FrameIndex,
438                            const TargetRegisterClass *RC,
439                            const TargetRegisterInfo *TRI) const override;
440 
441   // Emits a register spill without updating the register class for vector
442   // registers. This ensures that when we spill a vector register the
443   // element order in the register is the same as it was in memory.
444   void storeRegToStackSlotNoUpd(MachineBasicBlock &MBB,
445                                 MachineBasicBlock::iterator MBBI,
446                                 unsigned SrcReg, bool isKill, int FrameIndex,
447                                 const TargetRegisterClass *RC,
448                                 const TargetRegisterInfo *TRI) const;
449 
450   void loadRegFromStackSlot(MachineBasicBlock &MBB,
451                             MachineBasicBlock::iterator MBBI,
452                             Register DestReg, int FrameIndex,
453                             const TargetRegisterClass *RC,
454                             const TargetRegisterInfo *TRI) const override;
455 
456   // Emits a register reload without updating the register class for vector
457   // registers. This ensures that when we reload a vector register the
458   // element order in the register is the same as it was in memory.
459   void loadRegFromStackSlotNoUpd(MachineBasicBlock &MBB,
460                                  MachineBasicBlock::iterator MBBI,
461                                  unsigned DestReg, int FrameIndex,
462                                  const TargetRegisterClass *RC,
463                                  const TargetRegisterInfo *TRI) const;
464 
465   unsigned getStoreOpcodeForSpill(const TargetRegisterClass *RC) const;
466 
467   unsigned getLoadOpcodeForSpill(const TargetRegisterClass *RC) const;
468 
469   bool
470   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
471 
472   bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, Register Reg,
473                      MachineRegisterInfo *MRI) const override;
474 
475   bool onlyFoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
476                          Register Reg) const;
477 
478   // If conversion by predication (only supported by some branch instructions).
479   // All of the profitability checks always return true; it is always
480   // profitable to use the predicated branches.
isProfitableToIfCvt(MachineBasicBlock & MBB,unsigned NumCycles,unsigned ExtraPredCycles,BranchProbability Probability)481   bool isProfitableToIfCvt(MachineBasicBlock &MBB,
482                           unsigned NumCycles, unsigned ExtraPredCycles,
483                           BranchProbability Probability) const override {
484     return true;
485   }
486 
487   bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
488                            unsigned NumT, unsigned ExtraT,
489                            MachineBasicBlock &FMBB,
490                            unsigned NumF, unsigned ExtraF,
491                            BranchProbability Probability) const override;
492 
isProfitableToDupForIfCvt(MachineBasicBlock & MBB,unsigned NumCycles,BranchProbability Probability)493   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
494                                  BranchProbability Probability) const override {
495     return true;
496   }
497 
isProfitableToUnpredicate(MachineBasicBlock & TMBB,MachineBasicBlock & FMBB)498   bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
499                                  MachineBasicBlock &FMBB) const override {
500     return false;
501   }
502 
503   // Predication support.
504   bool isPredicated(const MachineInstr &MI) const override;
505 
506   bool isSchedulingBoundary(const MachineInstr &MI,
507                             const MachineBasicBlock *MBB,
508                             const MachineFunction &MF) const override;
509 
510   bool PredicateInstruction(MachineInstr &MI,
511                             ArrayRef<MachineOperand> Pred) const override;
512 
513   bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
514                          ArrayRef<MachineOperand> Pred2) const override;
515 
516   bool ClobbersPredicate(MachineInstr &MI, std::vector<MachineOperand> &Pred,
517                          bool SkipDead) const override;
518 
519   // Comparison optimization.
520 
521   bool analyzeCompare(const MachineInstr &MI, Register &SrcReg,
522                       Register &SrcReg2, int &Mask, int &Value) const override;
523 
524   bool optimizeCompareInstr(MachineInstr &CmpInstr, Register SrcReg,
525                             Register SrcReg2, int Mask, int Value,
526                             const MachineRegisterInfo *MRI) const override;
527 
528 
529   /// Return true if get the base operand, byte offset of an instruction and
530   /// the memory width. Width is the size of memory that is being
531   /// loaded/stored (e.g. 1, 2, 4, 8).
532   bool getMemOperandWithOffsetWidth(const MachineInstr &LdSt,
533                                     const MachineOperand *&BaseOp,
534                                     int64_t &Offset, unsigned &Width,
535                                     const TargetRegisterInfo *TRI) const;
536 
537   /// Get the base operand and byte offset of an instruction that reads/writes
538   /// memory.
539   bool getMemOperandsWithOffsetWidth(
540       const MachineInstr &LdSt,
541       SmallVectorImpl<const MachineOperand *> &BaseOps, int64_t &Offset,
542       bool &OffsetIsScalable, unsigned &Width,
543       const TargetRegisterInfo *TRI) const override;
544 
545   /// Returns true if the two given memory operations should be scheduled
546   /// adjacent.
547   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
548                            ArrayRef<const MachineOperand *> BaseOps2,
549                            unsigned NumLoads, unsigned NumBytes) const override;
550 
551   /// Return true if two MIs access different memory addresses and false
552   /// otherwise
553   bool
554   areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
555                                   const MachineInstr &MIb) const override;
556 
557   /// GetInstSize - Return the number of bytes of code the specified
558   /// instruction may be.  This returns the maximum number of bytes.
559   ///
560   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
561 
562   void getNoop(MCInst &NopInst) const override;
563 
564   std::pair<unsigned, unsigned>
565   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
566 
567   ArrayRef<std::pair<unsigned, const char *>>
568   getSerializableDirectMachineOperandTargetFlags() const override;
569 
570   ArrayRef<std::pair<unsigned, const char *>>
571   getSerializableBitmaskMachineOperandTargetFlags() const override;
572 
573   // Expand VSX Memory Pseudo instruction to either a VSX or a FP instruction.
574   bool expandVSXMemPseudo(MachineInstr &MI) const;
575 
576   // Lower pseudo instructions after register allocation.
577   bool expandPostRAPseudo(MachineInstr &MI) const override;
578 
isVFRegister(unsigned Reg)579   static bool isVFRegister(unsigned Reg) {
580     return Reg >= PPC::VF0 && Reg <= PPC::VF31;
581   }
isVRRegister(unsigned Reg)582   static bool isVRRegister(unsigned Reg) {
583     return Reg >= PPC::V0 && Reg <= PPC::V31;
584   }
585   const TargetRegisterClass *updatedRC(const TargetRegisterClass *RC) const;
586   static int getRecordFormOpcode(unsigned Opcode);
587 
588   bool isTOCSaveMI(const MachineInstr &MI) const;
589 
590   bool isSignOrZeroExtended(const MachineInstr &MI, bool SignExt,
591                             const unsigned PhiDepth) const;
592 
593   /// Return true if the output of the instruction is always a sign-extended,
594   /// i.e. 0 to 31-th bits are same as 32-th bit.
595   bool isSignExtended(const MachineInstr &MI, const unsigned depth = 0) const {
596     return isSignOrZeroExtended(MI, true, depth);
597   }
598 
599   /// Return true if the output of the instruction is always zero-extended,
600   /// i.e. 0 to 31-th bits are all zeros
601   bool isZeroExtended(const MachineInstr &MI, const unsigned depth = 0) const {
602    return isSignOrZeroExtended(MI, false, depth);
603   }
604 
605   bool convertToImmediateForm(MachineInstr &MI,
606                               MachineInstr **KilledDef = nullptr) const;
607   bool foldFrameOffset(MachineInstr &MI) const;
608   bool combineRLWINM(MachineInstr &MI, MachineInstr **ToErase = nullptr) const;
609   bool isADDIInstrEligibleForFolding(MachineInstr &ADDIMI, int64_t &Imm) const;
610   bool isADDInstrEligibleForFolding(MachineInstr &ADDMI) const;
611   bool isImmInstrEligibleForFolding(MachineInstr &MI, unsigned &BaseReg,
612                                     unsigned &XFormOpcode,
613                                     int64_t &OffsetOfImmInstr,
614                                     ImmInstrInfo &III) const;
615   bool isValidToBeChangedReg(MachineInstr *ADDMI, unsigned Index,
616                              MachineInstr *&ADDIMI, int64_t &OffsetAddi,
617                              int64_t OffsetImm) const;
618 
619   /// Fixup killed/dead flag for register \p RegNo between instructions [\p
620   /// StartMI, \p EndMI]. Some pre-RA or post-RA transformations may violate
621   /// register killed/dead flags semantics, this function can be called to fix
622   /// up. Before calling this function,
623   /// 1. Ensure that \p RegNo liveness is killed after instruction \p EndMI.
624   /// 2. Ensure that there is no new definition between (\p StartMI, \p EndMI)
625   ///    and possible definition for \p RegNo is \p StartMI or \p EndMI. For
626   ///    pre-RA cases, definition may be \p StartMI through COPY, \p StartMI
627   ///    will be adjust to true definition.
628   /// 3. We can do accurate fixup for the case when all instructions between
629   ///    [\p StartMI, \p EndMI] are in same basic block.
630   /// 4. For the case when \p StartMI and \p EndMI are not in same basic block,
631   ///    we conservatively clear kill flag for all uses of \p RegNo for pre-RA
632   ///    and for post-RA, we give an assertion as without reaching definition
633   ///    analysis post-RA, \p StartMI and \p EndMI are hard to keep right.
634   void fixupIsDeadOrKill(MachineInstr *StartMI, MachineInstr *EndMI,
635                          unsigned RegNo) const;
636   void replaceInstrWithLI(MachineInstr &MI, const LoadImmediateInfo &LII) const;
637   void replaceInstrOperandWithImm(MachineInstr &MI, unsigned OpNo,
638                                   int64_t Imm) const;
639 
640   bool instrHasImmForm(unsigned Opc, bool IsVFReg, ImmInstrInfo &III,
641                        bool PostRA) const;
642 
643   // In PostRA phase, try to find instruction defines \p Reg before \p MI.
644   // \p SeenIntermediate is set to true if uses between DefMI and \p MI exist.
645   MachineInstr *getDefMIPostRA(unsigned Reg, MachineInstr &MI,
646                                bool &SeenIntermediateUse) const;
647 
648   /// getRegNumForOperand - some operands use different numbering schemes
649   /// for the same registers. For example, a VSX instruction may have any of
650   /// vs0-vs63 allocated whereas an Altivec instruction could only have
651   /// vs32-vs63 allocated (numbered as v0-v31). This function returns the actual
652   /// register number needed for the opcode/operand number combination.
653   /// The operand number argument will be useful when we need to extend this
654   /// to instructions that use both Altivec and VSX numbering (for different
655   /// operands).
getRegNumForOperand(const MCInstrDesc & Desc,unsigned Reg,unsigned OpNo)656   static unsigned getRegNumForOperand(const MCInstrDesc &Desc, unsigned Reg,
657                                       unsigned OpNo) {
658     int16_t regClass = Desc.OpInfo[OpNo].RegClass;
659     switch (regClass) {
660       // We store F0-F31, VF0-VF31 in MCOperand and it should be F0-F31,
661       // VSX32-VSX63 during encoding/disassembling
662       case PPC::VSSRCRegClassID:
663       case PPC::VSFRCRegClassID:
664         if (isVFRegister(Reg))
665           return PPC::VSX32 + (Reg - PPC::VF0);
666         break;
667       // We store VSL0-VSL31, V0-V31 in MCOperand and it should be VSL0-VSL31,
668       // VSX32-VSX63 during encoding/disassembling
669       case PPC::VSRCRegClassID:
670         if (isVRRegister(Reg))
671           return PPC::VSX32 + (Reg - PPC::V0);
672         break;
673       // Other RegClass doesn't need mapping
674       default:
675         break;
676     }
677     return Reg;
678   }
679 
680   /// Check \p Opcode is BDNZ (Decrement CTR and branch if it is still nonzero).
681   bool isBDNZ(unsigned Opcode) const;
682 
683   /// Find the hardware loop instruction used to set-up the specified loop.
684   /// On PPC, we have two instructions used to set-up the hardware loop
685   /// (MTCTRloop, MTCTR8loop) with corresponding endloop (BDNZ, BDNZ8)
686   /// instructions to indicate the end of a loop.
687   MachineInstr *
688   findLoopInstr(MachineBasicBlock &PreHeader,
689                 SmallPtrSet<MachineBasicBlock *, 8> &Visited) const;
690 
691   /// Analyze loop L, which must be a single-basic-block loop, and if the
692   /// conditions can be understood enough produce a PipelinerLoopInfo object.
693   std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
694   analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const override;
695 };
696 
697 }
698 
699 #endif
700