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   /// This instruction produced a sign extended result.
72   SExt32To64 = 0x1 << (NewDef_Shift + 2),
73   /// This instruction produced a zero extended result.
74   ZExt32To64 = 0x1 << (NewDef_Shift + 3)
75 };
76 } // end namespace PPCII
77 
78 // Instructions that have an immediate form might be convertible to that
79 // form if the correct input is a result of a load immediate. In order to
80 // know whether the transformation is special, we might need to know some
81 // of the details of the two forms.
82 struct ImmInstrInfo {
83   // Is the immediate field in the immediate form signed or unsigned?
84   uint64_t SignedImm : 1;
85   // Does the immediate need to be a multiple of some value?
86   uint64_t ImmMustBeMultipleOf : 5;
87   // Is R0/X0 treated specially by the original r+r instruction?
88   // If so, in which operand?
89   uint64_t ZeroIsSpecialOrig : 3;
90   // Is R0/X0 treated specially by the new r+i instruction?
91   // If so, in which operand?
92   uint64_t ZeroIsSpecialNew : 3;
93   // Is the operation commutative?
94   uint64_t IsCommutative : 1;
95   // The operand number to check for add-immediate def.
96   uint64_t OpNoForForwarding : 3;
97   // The operand number for the immediate.
98   uint64_t ImmOpNo : 3;
99   // The opcode of the new instruction.
100   uint64_t ImmOpcode : 16;
101   // The size of the immediate.
102   uint64_t ImmWidth : 5;
103   // The immediate should be truncated to N bits.
104   uint64_t TruncateImmTo : 5;
105   // Is the instruction summing the operand
106   uint64_t IsSummingOperands : 1;
107 };
108 
109 // Information required to convert an instruction to just a materialized
110 // immediate.
111 struct LoadImmediateInfo {
112   unsigned Imm : 16;
113   unsigned Is64Bit : 1;
114   unsigned SetCR : 1;
115 };
116 
117 // Index into the OpcodesForSpill array.
118 enum SpillOpcodeKey {
119   SOK_Int4Spill,
120   SOK_Int8Spill,
121   SOK_Float8Spill,
122   SOK_Float4Spill,
123   SOK_CRSpill,
124   SOK_CRBitSpill,
125   SOK_VRVectorSpill,
126   SOK_VSXVectorSpill,
127   SOK_VectorFloat8Spill,
128   SOK_VectorFloat4Spill,
129   SOK_SpillToVSR,
130   SOK_PairedVecSpill,
131   SOK_AccumulatorSpill,
132   SOK_UAccumulatorSpill,
133   SOK_WAccumulatorSpill,
134   SOK_SPESpill,
135   SOK_PairedG8Spill,
136   SOK_LastOpcodeSpill // This must be last on the enum.
137 };
138 
139 // Define list of load and store spill opcodes.
140 #define NoInstr PPC::INSTRUCTION_LIST_END
141 #define Pwr8LoadOpcodes                                                        \
142   {                                                                            \
143     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
144         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXVD2X, PPC::LXSDX, PPC::LXSSPX,    \
145         PPC::SPILLTOVSR_LD, NoInstr, NoInstr, NoInstr, NoInstr, PPC::EVLDD,    \
146         PPC::RESTORE_QUADWORD                                                  \
147   }
148 
149 #define Pwr9LoadOpcodes                                                        \
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, NoInstr, NoInstr, NoInstr,         \
154         NoInstr, NoInstr, PPC::RESTORE_QUADWORD                                \
155   }
156 
157 #define Pwr10LoadOpcodes                                                       \
158   {                                                                            \
159     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
160         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXV, PPC::DFLOADf64,                \
161         PPC::DFLOADf32, PPC::SPILLTOVSR_LD, PPC::LXVP, PPC::RESTORE_ACC,       \
162         PPC::RESTORE_UACC, NoInstr, NoInstr, PPC::RESTORE_QUADWORD             \
163   }
164 
165 #define FutureLoadOpcodes                                                      \
166   {                                                                            \
167     PPC::LWZ, PPC::LD, PPC::LFD, PPC::LFS, PPC::RESTORE_CR,                    \
168         PPC::RESTORE_CRBIT, PPC::LVX, PPC::LXV, PPC::DFLOADf64,                \
169         PPC::DFLOADf32, PPC::SPILLTOVSR_LD, PPC::LXVP, PPC::RESTORE_ACC,       \
170         PPC::RESTORE_UACC, PPC::RESTORE_WACC, NoInstr, PPC::RESTORE_QUADWORD   \
171   }
172 
173 #define Pwr8StoreOpcodes                                                       \
174   {                                                                            \
175     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
176         PPC::STVX, PPC::STXVD2X, PPC::STXSDX, PPC::STXSSPX,                    \
177         PPC::SPILLTOVSR_ST, NoInstr, NoInstr, NoInstr, NoInstr, PPC::EVSTDD,   \
178         PPC::SPILL_QUADWORD                                                    \
179   }
180 
181 #define Pwr9StoreOpcodes                                                       \
182   {                                                                            \
183     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
184         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
185         PPC::SPILLTOVSR_ST, NoInstr, NoInstr, NoInstr, NoInstr, NoInstr,       \
186         PPC::SPILL_QUADWORD                                                    \
187   }
188 
189 #define Pwr10StoreOpcodes                                                      \
190   {                                                                            \
191     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
192         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
193         PPC::SPILLTOVSR_ST, PPC::STXVP, PPC::SPILL_ACC, PPC::SPILL_UACC,       \
194         NoInstr, NoInstr, PPC::SPILL_QUADWORD                                  \
195   }
196 
197 #define FutureStoreOpcodes                                                     \
198   {                                                                            \
199     PPC::STW, PPC::STD, PPC::STFD, PPC::STFS, PPC::SPILL_CR, PPC::SPILL_CRBIT, \
200         PPC::STVX, PPC::STXV, PPC::DFSTOREf64, PPC::DFSTOREf32,                \
201         PPC::SPILLTOVSR_ST, PPC::STXVP, PPC::SPILL_ACC, PPC::SPILL_UACC,       \
202         PPC::SPILL_WACC, NoInstr, PPC::SPILL_QUADWORD                          \
203   }
204 
205 // Initialize arrays for load and store spill opcodes on supported subtargets.
206 #define StoreOpcodesForSpill                                                   \
207   { Pwr8StoreOpcodes, Pwr9StoreOpcodes, Pwr10StoreOpcodes, FutureStoreOpcodes }
208 #define LoadOpcodesForSpill                                                    \
209   { Pwr8LoadOpcodes, Pwr9LoadOpcodes, Pwr10LoadOpcodes, FutureLoadOpcodes }
210 
211 class PPCSubtarget;
212 class PPCInstrInfo : public PPCGenInstrInfo {
213   PPCSubtarget &Subtarget;
214   const PPCRegisterInfo RI;
215   const unsigned StoreSpillOpcodesArray[4][SOK_LastOpcodeSpill] =
216       StoreOpcodesForSpill;
217   const unsigned LoadSpillOpcodesArray[4][SOK_LastOpcodeSpill] =
218       LoadOpcodesForSpill;
219 
220   void StoreRegToStackSlot(MachineFunction &MF, unsigned SrcReg, bool isKill,
221                            int FrameIdx, const TargetRegisterClass *RC,
222                            SmallVectorImpl<MachineInstr *> &NewMIs) const;
223   void LoadRegFromStackSlot(MachineFunction &MF, const DebugLoc &DL,
224                             unsigned DestReg, int FrameIdx,
225                             const TargetRegisterClass *RC,
226                             SmallVectorImpl<MachineInstr *> &NewMIs) const;
227 
228   // Replace the instruction with single LI if possible. \p DefMI must be LI or
229   // LI8.
230   bool simplifyToLI(MachineInstr &MI, MachineInstr &DefMI,
231                     unsigned OpNoForForwarding, MachineInstr **KilledDef) const;
232   // If the inst is imm-form and its register operand is produced by a ADDI, put
233   // the imm into the inst directly and remove the ADDI if possible.
234   bool transformToNewImmFormFedByAdd(MachineInstr &MI, MachineInstr &DefMI,
235                                      unsigned OpNoForForwarding) const;
236   // If the inst is x-form and has imm-form and one of its operand is produced
237   // by a LI, put the imm into the inst directly and remove the LI if possible.
238   bool transformToImmFormFedByLI(MachineInstr &MI, const ImmInstrInfo &III,
239                                  unsigned ConstantOpNo,
240                                  MachineInstr &DefMI) const;
241   // If the inst is x-form and has imm-form and one of its operand is produced
242   // by an add-immediate, try to transform it when possible.
243   bool transformToImmFormFedByAdd(MachineInstr &MI, const ImmInstrInfo &III,
244                                   unsigned ConstantOpNo, MachineInstr &DefMI,
245                                   bool KillDefMI) const;
246   // Try to find that, if the instruction 'MI' contains any operand that
247   // could be forwarded from some inst that feeds it. If yes, return the
248   // Def of that operand. And OpNoForForwarding is the operand index in
249   // the 'MI' for that 'Def'. If we see another use of this Def between
250   // the Def and the MI, SeenIntermediateUse becomes 'true'.
251   MachineInstr *getForwardingDefMI(MachineInstr &MI,
252                                    unsigned &OpNoForForwarding,
253                                    bool &SeenIntermediateUse) const;
254 
255   // Can the user MI have it's source at index \p OpNoForForwarding
256   // forwarded from an add-immediate that feeds it?
257   bool isUseMIElgibleForForwarding(MachineInstr &MI, const ImmInstrInfo &III,
258                                    unsigned OpNoForForwarding) const;
259   bool isDefMIElgibleForForwarding(MachineInstr &DefMI,
260                                    const ImmInstrInfo &III,
261                                    MachineOperand *&ImmMO,
262                                    MachineOperand *&RegMO) const;
263   bool isImmElgibleForForwarding(const MachineOperand &ImmMO,
264                                  const MachineInstr &DefMI,
265                                  const ImmInstrInfo &III,
266                                  int64_t &Imm,
267                                  int64_t BaseImm = 0) const;
268   bool isRegElgibleForForwarding(const MachineOperand &RegMO,
269                                  const MachineInstr &DefMI,
270                                  const MachineInstr &MI, bool KillDefMI,
271                                  bool &IsFwdFeederRegKilled,
272                                  bool &SeenIntermediateUse) const;
273   unsigned getSpillTarget() const;
274   ArrayRef<unsigned> getStoreOpcodesForSpillArray() const;
275   ArrayRef<unsigned> getLoadOpcodesForSpillArray() const;
276   unsigned getSpillIndex(const TargetRegisterClass *RC) const;
277   int16_t getFMAOpIdxInfo(unsigned Opcode) const;
278   void reassociateFMA(MachineInstr &Root, MachineCombinerPattern Pattern,
279                       SmallVectorImpl<MachineInstr *> &InsInstrs,
280                       SmallVectorImpl<MachineInstr *> &DelInstrs,
281                       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const;
282   bool isLoadFromConstantPool(MachineInstr *I) const;
283   Register
284   generateLoadForNewConst(unsigned Idx, MachineInstr *MI, Type *Ty,
285                           SmallVectorImpl<MachineInstr *> &InsInstrs) const;
286   const Constant *getConstantFromConstantPool(MachineInstr *I) const;
287   virtual void anchor();
288 
289 protected:
290   /// Commutes the operands in the given instruction.
291   /// The commutable operands are specified by their indices OpIdx1 and OpIdx2.
292   ///
293   /// Do not call this method for a non-commutable instruction or for
294   /// non-commutable pair of operand indices OpIdx1 and OpIdx2.
295   /// Even though the instruction is commutable, the method may still
296   /// fail to commute the operands, null pointer is returned in such cases.
297   ///
298   /// For example, we can commute rlwimi instructions, but only if the
299   /// rotate amt is zero.  We also have to munge the immediates a bit.
300   MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
301                                        unsigned OpIdx1,
302                                        unsigned OpIdx2) const override;
303 
304 public:
305   explicit PPCInstrInfo(PPCSubtarget &STI);
306 
307   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
308   /// such, whenever a client has an instance of instruction info, it should
309   /// always be able to get register info as well (through this method).
310   ///
getRegisterInfo()311   const PPCRegisterInfo &getRegisterInfo() const { return RI; }
312 
isXFormMemOp(unsigned Opcode)313   bool isXFormMemOp(unsigned Opcode) const {
314     return get(Opcode).TSFlags & PPCII::XFormMemOp;
315   }
isPrefixed(unsigned Opcode)316   bool isPrefixed(unsigned Opcode) const {
317     return get(Opcode).TSFlags & PPCII::Prefixed;
318   }
isSExt32To64(unsigned Opcode)319   bool isSExt32To64(unsigned Opcode) const {
320     return get(Opcode).TSFlags & PPCII::SExt32To64;
321   }
isZExt32To64(unsigned Opcode)322   bool isZExt32To64(unsigned Opcode) const {
323     return get(Opcode).TSFlags & PPCII::ZExt32To64;
324   }
325 
326   /// Check if Opcode corresponds to a call instruction that should be marked
327   /// with the NOTOC relocation.
isNoTOCCallInstr(unsigned Opcode)328   bool isNoTOCCallInstr(unsigned Opcode) const {
329     if (!get(Opcode).isCall())
330       return false;
331 
332     switch (Opcode) {
333     default:
334 #ifndef NDEBUG
335       llvm_unreachable("Unknown call opcode");
336 #endif
337       return false;
338     case PPC::BL8_NOTOC:
339     case PPC::BL8_NOTOC_TLS:
340     case PPC::BL8_NOTOC_RM:
341       return true;
342 #ifndef NDEBUG
343     case PPC::BL8:
344     case PPC::BL:
345     case PPC::BL8_TLS:
346     case PPC::BL_TLS:
347     case PPC::BLA8:
348     case PPC::BLA:
349     case PPC::BCCL:
350     case PPC::BCCLA:
351     case PPC::BCL:
352     case PPC::BCLn:
353     case PPC::BL8_NOP:
354     case PPC::BL_NOP:
355     case PPC::BL8_NOP_TLS:
356     case PPC::BLA8_NOP:
357     case PPC::BCTRL8:
358     case PPC::BCTRL:
359     case PPC::BCCCTRL8:
360     case PPC::BCCCTRL:
361     case PPC::BCCTRL8:
362     case PPC::BCCTRL:
363     case PPC::BCCTRL8n:
364     case PPC::BCCTRLn:
365     case PPC::BL8_RM:
366     case PPC::BLA8_RM:
367     case PPC::BL8_NOP_RM:
368     case PPC::BLA8_NOP_RM:
369     case PPC::BCTRL8_RM:
370     case PPC::BCTRL8_LDinto_toc:
371     case PPC::BCTRL8_LDinto_toc_RM:
372     case PPC::BL8_TLS_:
373     case PPC::TCRETURNdi8:
374     case PPC::TCRETURNai8:
375     case PPC::TCRETURNri8:
376     case PPC::TAILBCTR8:
377     case PPC::TAILB8:
378     case PPC::TAILBA8:
379     case PPC::BCLalways:
380     case PPC::BLRL:
381     case PPC::BCCLRL:
382     case PPC::BCLRL:
383     case PPC::BCLRLn:
384     case PPC::BDZL:
385     case PPC::BDNZL:
386     case PPC::BDZLA:
387     case PPC::BDNZLA:
388     case PPC::BDZLp:
389     case PPC::BDNZLp:
390     case PPC::BDZLAp:
391     case PPC::BDNZLAp:
392     case PPC::BDZLm:
393     case PPC::BDNZLm:
394     case PPC::BDZLAm:
395     case PPC::BDNZLAm:
396     case PPC::BDZLRL:
397     case PPC::BDNZLRL:
398     case PPC::BDZLRLp:
399     case PPC::BDNZLRLp:
400     case PPC::BDZLRLm:
401     case PPC::BDNZLRLm:
402     case PPC::BL_RM:
403     case PPC::BLA_RM:
404     case PPC::BL_NOP_RM:
405     case PPC::BCTRL_RM:
406     case PPC::TCRETURNdi:
407     case PPC::TCRETURNai:
408     case PPC::TCRETURNri:
409     case PPC::BCTRL_LWZinto_toc:
410     case PPC::BCTRL_LWZinto_toc_RM:
411     case PPC::TAILBCTR:
412     case PPC::TAILB:
413     case PPC::TAILBA:
414       return false;
415 #endif
416     }
417   }
418 
isSameClassPhysRegCopy(unsigned Opcode)419   static bool isSameClassPhysRegCopy(unsigned Opcode) {
420     unsigned CopyOpcodes[] = {PPC::OR,        PPC::OR8,   PPC::FMR,
421                               PPC::VOR,       PPC::XXLOR, PPC::XXLORf,
422                               PPC::XSCPSGNDP, PPC::MCRF,  PPC::CROR,
423                               PPC::EVOR,      -1U};
424     for (int i = 0; CopyOpcodes[i] != -1U; i++)
425       if (Opcode == CopyOpcodes[i])
426         return true;
427     return false;
428   }
429 
430   ScheduleHazardRecognizer *
431   CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
432                                const ScheduleDAG *DAG) const override;
433   ScheduleHazardRecognizer *
434   CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
435                                      const ScheduleDAG *DAG) const override;
436 
437   unsigned getInstrLatency(const InstrItineraryData *ItinData,
438                            const MachineInstr &MI,
439                            unsigned *PredCost = nullptr) const override;
440 
441   int getOperandLatency(const InstrItineraryData *ItinData,
442                         const MachineInstr &DefMI, unsigned DefIdx,
443                         const MachineInstr &UseMI,
444                         unsigned UseIdx) const override;
getOperandLatency(const InstrItineraryData * ItinData,SDNode * DefNode,unsigned DefIdx,SDNode * UseNode,unsigned UseIdx)445   int getOperandLatency(const InstrItineraryData *ItinData,
446                         SDNode *DefNode, unsigned DefIdx,
447                         SDNode *UseNode, unsigned UseIdx) const override {
448     return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
449                                               UseNode, UseIdx);
450   }
451 
hasLowDefLatency(const TargetSchedModel & SchedModel,const MachineInstr & DefMI,unsigned DefIdx)452   bool hasLowDefLatency(const TargetSchedModel &SchedModel,
453                         const MachineInstr &DefMI,
454                         unsigned DefIdx) const override {
455     // Machine LICM should hoist all instructions in low-register-pressure
456     // situations; none are sufficiently free to justify leaving in a loop
457     // body.
458     return false;
459   }
460 
useMachineCombiner()461   bool useMachineCombiner() const override {
462     return true;
463   }
464 
465   /// When getMachineCombinerPatterns() finds patterns, this function generates
466   /// the instructions that could replace the original code sequence
467   void genAlternativeCodeSequence(
468       MachineInstr &Root, MachineCombinerPattern Pattern,
469       SmallVectorImpl<MachineInstr *> &InsInstrs,
470       SmallVectorImpl<MachineInstr *> &DelInstrs,
471       DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;
472 
473   /// Return true when there is potentially a faster code sequence for a fma
474   /// chain ending in \p Root. All potential patterns are output in the \p
475   /// P array.
476   bool getFMAPatterns(MachineInstr &Root,
477                       SmallVectorImpl<MachineCombinerPattern> &P,
478                       bool DoRegPressureReduce) const;
479 
480   /// Return true when there is potentially a faster code sequence
481   /// for an instruction chain ending in <Root>. All potential patterns are
482   /// output in the <Pattern> array.
483   bool getMachineCombinerPatterns(MachineInstr &Root,
484                                   SmallVectorImpl<MachineCombinerPattern> &P,
485                                   bool DoRegPressureReduce) const override;
486 
487   /// On PowerPC, we leverage machine combiner pass to reduce register pressure
488   /// when the register pressure is high for one BB.
489   /// Return true if register pressure for \p MBB is high and ABI is supported
490   /// to reduce register pressure. Otherwise return false.
491   bool shouldReduceRegisterPressure(
492       const MachineBasicBlock *MBB,
493       const RegisterClassInfo *RegClassInfo) const override;
494 
495   /// Fixup the placeholders we put in genAlternativeCodeSequence() for
496   /// MachineCombiner.
497   void
498   finalizeInsInstrs(MachineInstr &Root, MachineCombinerPattern &P,
499                     SmallVectorImpl<MachineInstr *> &InsInstrs) const override;
500 
501   bool isAssociativeAndCommutative(const MachineInstr &Inst,
502                                    bool Invert) const override;
503 
504   /// On PowerPC, we try to reassociate FMA chain which will increase
505   /// instruction size. Set extension resource length limit to 1 for edge case.
506   /// Resource Length is calculated by scaled resource usage in getCycles().
507   /// Because of the division in getCycles(), it returns different cycles due to
508   /// legacy scaled resource usage. So new resource length may be same with
509   /// legacy or 1 bigger than legacy.
510   /// We need to execlude the 1 bigger case even the resource length is not
511   /// perserved for more FMA chain reassociations on PowerPC.
getExtendResourceLenLimit()512   int getExtendResourceLenLimit() const override { return 1; }
513 
514   void setSpecialOperandAttr(MachineInstr &OldMI1, MachineInstr &OldMI2,
515                              MachineInstr &NewMI1,
516                              MachineInstr &NewMI2) const override;
517 
518   // PowerPC specific version of setSpecialOperandAttr that copies Flags to MI
519   // and clears nuw, nsw, and exact flags.
520   void setSpecialOperandAttr(MachineInstr &MI, uint16_t Flags) const;
521 
522   bool isCoalescableExtInstr(const MachineInstr &MI,
523                              Register &SrcReg, Register &DstReg,
524                              unsigned &SubIdx) const override;
525   unsigned isLoadFromStackSlot(const MachineInstr &MI,
526                                int &FrameIndex) const override;
527   bool isReallyTriviallyReMaterializable(const MachineInstr &MI) const override;
528   unsigned isStoreToStackSlot(const MachineInstr &MI,
529                               int &FrameIndex) const override;
530 
531   bool findCommutedOpIndices(const MachineInstr &MI, unsigned &SrcOpIdx1,
532                              unsigned &SrcOpIdx2) const override;
533 
534   void insertNoop(MachineBasicBlock &MBB,
535                   MachineBasicBlock::iterator MI) const override;
536 
537 
538   // Branch analysis.
539   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
540                      MachineBasicBlock *&FBB,
541                      SmallVectorImpl<MachineOperand> &Cond,
542                      bool AllowModify) const override;
543   unsigned removeBranch(MachineBasicBlock &MBB,
544                         int *BytesRemoved = nullptr) const override;
545   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
546                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
547                         const DebugLoc &DL,
548                         int *BytesAdded = nullptr) const override;
549 
550   // Select analysis.
551   bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
552                        Register, Register, Register, int &, int &,
553                        int &) const override;
554   void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
555                     const DebugLoc &DL, Register DstReg,
556                     ArrayRef<MachineOperand> Cond, Register TrueReg,
557                     Register FalseReg) const override;
558 
559   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator I,
560                    const DebugLoc &DL, MCRegister DestReg, MCRegister SrcReg,
561                    bool KillSrc) const override;
562 
563   void storeRegToStackSlot(MachineBasicBlock &MBB,
564                            MachineBasicBlock::iterator MBBI, Register SrcReg,
565                            bool isKill, int FrameIndex,
566                            const TargetRegisterClass *RC,
567                            const TargetRegisterInfo *TRI,
568                            Register VReg) const override;
569 
570   // Emits a register spill without updating the register class for vector
571   // registers. This ensures that when we spill a vector register the
572   // element order in the register is the same as it was in memory.
573   void storeRegToStackSlotNoUpd(MachineBasicBlock &MBB,
574                                 MachineBasicBlock::iterator MBBI,
575                                 unsigned SrcReg, bool isKill, int FrameIndex,
576                                 const TargetRegisterClass *RC,
577                                 const TargetRegisterInfo *TRI) const;
578 
579   void loadRegFromStackSlot(MachineBasicBlock &MBB,
580                             MachineBasicBlock::iterator MBBI, Register DestReg,
581                             int FrameIndex, const TargetRegisterClass *RC,
582                             const TargetRegisterInfo *TRI,
583                             Register VReg) const override;
584 
585   // Emits a register reload without updating the register class for vector
586   // registers. This ensures that when we reload a vector register the
587   // element order in the register is the same as it was in memory.
588   void loadRegFromStackSlotNoUpd(MachineBasicBlock &MBB,
589                                  MachineBasicBlock::iterator MBBI,
590                                  unsigned DestReg, int FrameIndex,
591                                  const TargetRegisterClass *RC,
592                                  const TargetRegisterInfo *TRI) const;
593 
594   unsigned getStoreOpcodeForSpill(const TargetRegisterClass *RC) const;
595 
596   unsigned getLoadOpcodeForSpill(const TargetRegisterClass *RC) const;
597 
598   bool
599   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
600 
601   bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, Register Reg,
602                      MachineRegisterInfo *MRI) const override;
603 
604   bool onlyFoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI,
605                          Register Reg) const;
606 
607   // If conversion by predication (only supported by some branch instructions).
608   // All of the profitability checks always return true; it is always
609   // profitable to use the predicated branches.
isProfitableToIfCvt(MachineBasicBlock & MBB,unsigned NumCycles,unsigned ExtraPredCycles,BranchProbability Probability)610   bool isProfitableToIfCvt(MachineBasicBlock &MBB,
611                           unsigned NumCycles, unsigned ExtraPredCycles,
612                           BranchProbability Probability) const override {
613     return true;
614   }
615 
616   bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
617                            unsigned NumT, unsigned ExtraT,
618                            MachineBasicBlock &FMBB,
619                            unsigned NumF, unsigned ExtraF,
620                            BranchProbability Probability) const override;
621 
isProfitableToDupForIfCvt(MachineBasicBlock & MBB,unsigned NumCycles,BranchProbability Probability)622   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
623                                  BranchProbability Probability) const override {
624     return true;
625   }
626 
isProfitableToUnpredicate(MachineBasicBlock & TMBB,MachineBasicBlock & FMBB)627   bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
628                                  MachineBasicBlock &FMBB) const override {
629     return false;
630   }
631 
632   // Predication support.
633   bool isPredicated(const MachineInstr &MI) const override;
634 
635   bool isSchedulingBoundary(const MachineInstr &MI,
636                             const MachineBasicBlock *MBB,
637                             const MachineFunction &MF) const override;
638 
639   bool PredicateInstruction(MachineInstr &MI,
640                             ArrayRef<MachineOperand> Pred) const override;
641 
642   bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
643                          ArrayRef<MachineOperand> Pred2) const override;
644 
645   bool ClobbersPredicate(MachineInstr &MI, std::vector<MachineOperand> &Pred,
646                          bool SkipDead) const override;
647 
648   // Comparison optimization.
649 
650   bool analyzeCompare(const MachineInstr &MI, Register &SrcReg,
651                       Register &SrcReg2, int64_t &Mask,
652                       int64_t &Value) const override;
653 
654   bool optimizeCompareInstr(MachineInstr &CmpInstr, Register SrcReg,
655                             Register SrcReg2, int64_t Mask, int64_t Value,
656                             const MachineRegisterInfo *MRI) const override;
657 
658 
659   /// Return true if get the base operand, byte offset of an instruction and
660   /// the memory width. Width is the size of memory that is being
661   /// loaded/stored (e.g. 1, 2, 4, 8).
662   bool getMemOperandWithOffsetWidth(const MachineInstr &LdSt,
663                                     const MachineOperand *&BaseOp,
664                                     int64_t &Offset, unsigned &Width,
665                                     const TargetRegisterInfo *TRI) const;
666 
667   bool optimizeCmpPostRA(MachineInstr &MI) const;
668 
669   /// Get the base operand and byte offset of an instruction that reads/writes
670   /// memory.
671   bool getMemOperandsWithOffsetWidth(
672       const MachineInstr &LdSt,
673       SmallVectorImpl<const MachineOperand *> &BaseOps, int64_t &Offset,
674       bool &OffsetIsScalable, unsigned &Width,
675       const TargetRegisterInfo *TRI) const override;
676 
677   /// Returns true if the two given memory operations should be scheduled
678   /// adjacent.
679   bool shouldClusterMemOps(ArrayRef<const MachineOperand *> BaseOps1,
680                            ArrayRef<const MachineOperand *> BaseOps2,
681                            unsigned NumLoads, unsigned NumBytes) const override;
682 
683   /// Return true if two MIs access different memory addresses and false
684   /// otherwise
685   bool
686   areMemAccessesTriviallyDisjoint(const MachineInstr &MIa,
687                                   const MachineInstr &MIb) const override;
688 
689   /// GetInstSize - Return the number of bytes of code the specified
690   /// instruction may be.  This returns the maximum number of bytes.
691   ///
692   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
693 
694   MCInst getNop() const override;
695 
696   std::pair<unsigned, unsigned>
697   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
698 
699   ArrayRef<std::pair<unsigned, const char *>>
700   getSerializableDirectMachineOperandTargetFlags() const override;
701 
702   ArrayRef<std::pair<unsigned, const char *>>
703   getSerializableBitmaskMachineOperandTargetFlags() const override;
704 
705   // Expand VSX Memory Pseudo instruction to either a VSX or a FP instruction.
706   bool expandVSXMemPseudo(MachineInstr &MI) const;
707 
708   // Lower pseudo instructions after register allocation.
709   bool expandPostRAPseudo(MachineInstr &MI) const override;
710 
isVFRegister(unsigned Reg)711   static bool isVFRegister(unsigned Reg) {
712     return Reg >= PPC::VF0 && Reg <= PPC::VF31;
713   }
isVRRegister(unsigned Reg)714   static bool isVRRegister(unsigned Reg) {
715     return Reg >= PPC::V0 && Reg <= PPC::V31;
716   }
717   const TargetRegisterClass *updatedRC(const TargetRegisterClass *RC) const;
718   static int getRecordFormOpcode(unsigned Opcode);
719 
720   bool isTOCSaveMI(const MachineInstr &MI) const;
721 
722   std::pair<bool, bool>
723   isSignOrZeroExtended(const unsigned Reg, const unsigned BinOpDepth,
724                        const MachineRegisterInfo *MRI) const;
725 
726   // Return true if the register is sign-extended from 32 to 64 bits.
isSignExtended(const unsigned Reg,const MachineRegisterInfo * MRI)727   bool isSignExtended(const unsigned Reg,
728                       const MachineRegisterInfo *MRI) const {
729     return isSignOrZeroExtended(Reg, 0, MRI).first;
730   }
731 
732   // Return true if the register is zero-extended from 32 to 64 bits.
isZeroExtended(const unsigned Reg,const MachineRegisterInfo * MRI)733   bool isZeroExtended(const unsigned Reg,
734                       const MachineRegisterInfo *MRI) const {
735     return isSignOrZeroExtended(Reg, 0, MRI).second;
736   }
737 
738   bool convertToImmediateForm(MachineInstr &MI,
739                               MachineInstr **KilledDef = nullptr) const;
740   bool foldFrameOffset(MachineInstr &MI) const;
741   bool combineRLWINM(MachineInstr &MI, MachineInstr **ToErase = nullptr) const;
742   bool isADDIInstrEligibleForFolding(MachineInstr &ADDIMI, int64_t &Imm) const;
743   bool isADDInstrEligibleForFolding(MachineInstr &ADDMI) const;
744   bool isImmInstrEligibleForFolding(MachineInstr &MI, unsigned &BaseReg,
745                                     unsigned &XFormOpcode,
746                                     int64_t &OffsetOfImmInstr,
747                                     ImmInstrInfo &III) const;
748   bool isValidToBeChangedReg(MachineInstr *ADDMI, unsigned Index,
749                              MachineInstr *&ADDIMI, int64_t &OffsetAddi,
750                              int64_t OffsetImm) const;
751 
752   /// Fixup killed/dead flag for register \p RegNo between instructions [\p
753   /// StartMI, \p EndMI]. Some pre-RA or post-RA transformations may violate
754   /// register killed/dead flags semantics, this function can be called to fix
755   /// up. Before calling this function,
756   /// 1. Ensure that \p RegNo liveness is killed after instruction \p EndMI.
757   /// 2. Ensure that there is no new definition between (\p StartMI, \p EndMI)
758   ///    and possible definition for \p RegNo is \p StartMI or \p EndMI. For
759   ///    pre-RA cases, definition may be \p StartMI through COPY, \p StartMI
760   ///    will be adjust to true definition.
761   /// 3. We can do accurate fixup for the case when all instructions between
762   ///    [\p StartMI, \p EndMI] are in same basic block.
763   /// 4. For the case when \p StartMI and \p EndMI are not in same basic block,
764   ///    we conservatively clear kill flag for all uses of \p RegNo for pre-RA
765   ///    and for post-RA, we give an assertion as without reaching definition
766   ///    analysis post-RA, \p StartMI and \p EndMI are hard to keep right.
767   void fixupIsDeadOrKill(MachineInstr *StartMI, MachineInstr *EndMI,
768                          unsigned RegNo) const;
769   void replaceInstrWithLI(MachineInstr &MI, const LoadImmediateInfo &LII) const;
770   void replaceInstrOperandWithImm(MachineInstr &MI, unsigned OpNo,
771                                   int64_t Imm) const;
772 
773   bool instrHasImmForm(unsigned Opc, bool IsVFReg, ImmInstrInfo &III,
774                        bool PostRA) const;
775 
776   // In PostRA phase, try to find instruction defines \p Reg before \p MI.
777   // \p SeenIntermediate is set to true if uses between DefMI and \p MI exist.
778   MachineInstr *getDefMIPostRA(unsigned Reg, MachineInstr &MI,
779                                bool &SeenIntermediateUse) const;
780 
781   // Materialize immediate after RA.
782   void materializeImmPostRA(MachineBasicBlock &MBB,
783                             MachineBasicBlock::iterator MBBI,
784                             const DebugLoc &DL, Register Reg,
785                             int64_t Imm) const;
786 
787   /// getRegNumForOperand - some operands use different numbering schemes
788   /// for the same registers. For example, a VSX instruction may have any of
789   /// vs0-vs63 allocated whereas an Altivec instruction could only have
790   /// vs32-vs63 allocated (numbered as v0-v31). This function returns the actual
791   /// register number needed for the opcode/operand number combination.
792   /// The operand number argument will be useful when we need to extend this
793   /// to instructions that use both Altivec and VSX numbering (for different
794   /// operands).
getRegNumForOperand(const MCInstrDesc & Desc,unsigned Reg,unsigned OpNo)795   static unsigned getRegNumForOperand(const MCInstrDesc &Desc, unsigned Reg,
796                                       unsigned OpNo) {
797     int16_t regClass = Desc.operands()[OpNo].RegClass;
798     switch (regClass) {
799       // We store F0-F31, VF0-VF31 in MCOperand and it should be F0-F31,
800       // VSX32-VSX63 during encoding/disassembling
801       case PPC::VSSRCRegClassID:
802       case PPC::VSFRCRegClassID:
803         if (isVFRegister(Reg))
804           return PPC::VSX32 + (Reg - PPC::VF0);
805         break;
806       // We store VSL0-VSL31, V0-V31 in MCOperand and it should be VSL0-VSL31,
807       // VSX32-VSX63 during encoding/disassembling
808       case PPC::VSRCRegClassID:
809         if (isVRRegister(Reg))
810           return PPC::VSX32 + (Reg - PPC::V0);
811         break;
812       // Other RegClass doesn't need mapping
813       default:
814         break;
815     }
816     return Reg;
817   }
818 
819   /// Check \p Opcode is BDNZ (Decrement CTR and branch if it is still nonzero).
820   bool isBDNZ(unsigned Opcode) const;
821 
822   /// Find the hardware loop instruction used to set-up the specified loop.
823   /// On PPC, we have two instructions used to set-up the hardware loop
824   /// (MTCTRloop, MTCTR8loop) with corresponding endloop (BDNZ, BDNZ8)
825   /// instructions to indicate the end of a loop.
826   MachineInstr *
827   findLoopInstr(MachineBasicBlock &PreHeader,
828                 SmallPtrSet<MachineBasicBlock *, 8> &Visited) const;
829 
830   /// Analyze loop L, which must be a single-basic-block loop, and if the
831   /// conditions can be understood enough produce a PipelinerLoopInfo object.
832   std::unique_ptr<TargetInstrInfo::PipelinerLoopInfo>
833   analyzeLoopForPipelining(MachineBasicBlock *LoopBB) const override;
834 };
835 
836 }
837 
838 #endif
839