llvm/lib/Target/PowerPC/PPCInstrInfo.h

//===-- PPCInstrInfo.h - PowerPC Instruction Information --------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains the PowerPC implementation of the TargetInstrInfo class.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H
#define LLVM_LIB_TARGET_POWERPC_PPCINSTRINFO_H

#include "PPC.h"
#include "PPCRegisterInfo.h"
#include "llvm/Target/TargetInstrInfo.h"

#define GET_INSTRINFO_HEADER
#include "PPCGenInstrInfo.inc"

namespace llvm {

/// PPCII - This namespace holds all of the PowerPC target-specific
/// per-instruction flags.  These must match the corresponding definitions in
/// PPC.td and PPCInstrFormats.td.
namespace PPCII {
enum {
  // PPC970 Instruction Flags.  These flags describe the characteristics of the
  // PowerPC 970 (aka G5) dispatch groups and how they are formed out of
  // raw machine instructions.

  /// PPC970_First - This instruction starts a new dispatch group, so it will
  /// always be the first one in the group.
  PPC970_First = 0x1,

  /// PPC970_Single - This instruction starts a new dispatch group and
  /// terminates it, so it will be the sole instruction in the group.
  PPC970_Single = 0x2,

  /// PPC970_Cracked - This instruction is cracked into two pieces, requiring
  /// two dispatch pipes to be available to issue.
  PPC970_Cracked = 0x4,

  /// PPC970_Mask/Shift - This is a bitmask that selects the pipeline type that
  /// an instruction is issued to.
  PPC970_Shift = 3,
  PPC970_Mask = 0x07 << PPC970_Shift
};
enum PPC970_Unit {
  /// These are the various PPC970 execution unit pipelines.  Each instruction
  /// is one of these.
  PPC970_Pseudo = 0 << PPC970_Shift,   // Pseudo instruction
  PPC970_FXU    = 1 << PPC970_Shift,   // Fixed Point (aka Integer/ALU) Unit
  PPC970_LSU    = 2 << PPC970_Shift,   // Load Store Unit
  PPC970_FPU    = 3 << PPC970_Shift,   // Floating Point Unit
  PPC970_CRU    = 4 << PPC970_Shift,   // Control Register Unit
  PPC970_VALU   = 5 << PPC970_Shift,   // Vector ALU
  PPC970_VPERM  = 6 << PPC970_Shift,   // Vector Permute Unit
  PPC970_BRU    = 7 << PPC970_Shift    // Branch Unit
};
} // end namespace PPCII

namespace MachineCombinerPattern {
enum MC_PATTERN : int {
  // These are commutative variants for reassociating a computation chain
  // of the form:
  //   B = A op X (Prev)
  //   C = B op Y (Root)
  MC_REASSOC_AX_BY = 0,
  MC_REASSOC_AX_YB = 1,
  MC_REASSOC_XA_BY = 2,
  MC_REASSOC_XA_YB = 3,
};
} // end namespace MachineCombinerPattern

class PPCSubtarget;
class PPCInstrInfo : public PPCGenInstrInfo {
  PPCSubtarget &Subtarget;
  const PPCRegisterInfo RI;

  bool StoreRegToStackSlot(MachineFunction &MF,
                           unsigned SrcReg, bool isKill, int FrameIdx,
                           const TargetRegisterClass *RC,
                           SmallVectorImpl<MachineInstr*> &NewMIs,
                           bool &NonRI, bool &SpillsVRS) const;
  bool LoadRegFromStackSlot(MachineFunction &MF, DebugLoc DL,
                            unsigned DestReg, int FrameIdx,
                            const TargetRegisterClass *RC,
                            SmallVectorImpl<MachineInstr*> &NewMIs,
                            bool &NonRI, bool &SpillsVRS) const;
  virtual void anchor();
public:
  explicit PPCInstrInfo(PPCSubtarget &STI);

  /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
  /// such, whenever a client has an instance of instruction info, it should
  /// always be able to get register info as well (through this method).
  ///
  const PPCRegisterInfo &getRegisterInfo() const { return RI; }

  ScheduleHazardRecognizer *
  CreateTargetHazardRecognizer(const TargetSubtargetInfo *STI,
                               const ScheduleDAG *DAG) const override;
  ScheduleHazardRecognizer *
  CreateTargetPostRAHazardRecognizer(const InstrItineraryData *II,
                                     const ScheduleDAG *DAG) const override;

  unsigned getInstrLatency(const InstrItineraryData *ItinData,
                           const MachineInstr *MI,
                           unsigned *PredCost = nullptr) const override;

  int getOperandLatency(const InstrItineraryData *ItinData,
                        const MachineInstr *DefMI, unsigned DefIdx,
                        const MachineInstr *UseMI,
                        unsigned UseIdx) const override;
  int getOperandLatency(const InstrItineraryData *ItinData,
                        SDNode *DefNode, unsigned DefIdx,
                        SDNode *UseNode, unsigned UseIdx) const override {
    return PPCGenInstrInfo::getOperandLatency(ItinData, DefNode, DefIdx,
                                              UseNode, UseIdx);
  }

  bool hasLowDefLatency(const TargetSchedModel &SchedModel,
                        const MachineInstr *DefMI,
                        unsigned DefIdx) const override {
    // Machine LICM should hoist all instructions in low-register-pressure
    // situations; none are sufficiently free to justify leaving in a loop
    // body.
    return false;
  }

  bool useMachineCombiner() const override {
    return true;
  }
  
  /// Return true when there is potentially a faster code sequence
  /// for an instruction chain ending in <Root>. All potential patterns are
  /// output in the <Pattern> array.
  bool getMachineCombinerPatterns(
      MachineInstr &Root,
      SmallVectorImpl<MachineCombinerPattern::MC_PATTERN> &P) const override;
  
  /// When getMachineCombinerPatterns() finds a pattern, this function generates
  /// the instructions that could replace the original code sequence.
  void genAlternativeCodeSequence(
          MachineInstr &Root, MachineCombinerPattern::MC_PATTERN P,
          SmallVectorImpl<MachineInstr *> &InsInstrs,
          SmallVectorImpl<MachineInstr *> &DelInstrs,
          DenseMap<unsigned, unsigned> &InstrIdxForVirtReg) const override;

  bool isCoalescableExtInstr(const MachineInstr &MI,
                             unsigned &SrcReg, unsigned &DstReg,
                             unsigned &SubIdx) const override;
  unsigned isLoadFromStackSlot(const MachineInstr *MI,
                               int &FrameIndex) const override;
  unsigned isStoreToStackSlot(const MachineInstr *MI,
                              int &FrameIndex) const override;

  // commuteInstruction - We can commute rlwimi instructions, but only if the
  // rotate amt is zero.  We also have to munge the immediates a bit.
  MachineInstr *commuteInstruction(MachineInstr *MI, bool NewMI) const override;

  bool findCommutedOpIndices(MachineInstr *MI, unsigned &SrcOpIdx1,
                             unsigned &SrcOpIdx2) const override;

  void insertNoop(MachineBasicBlock &MBB,
                  MachineBasicBlock::iterator MI) const override;


  // Branch analysis.
  bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
                     MachineBasicBlock *&FBB,
                     SmallVectorImpl<MachineOperand> &Cond,
                     bool AllowModify) const override;
  unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
  unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
                        MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
                        DebugLoc DL) const override;

  // Select analysis.
  bool canInsertSelect(const MachineBasicBlock &, ArrayRef<MachineOperand> Cond,
                       unsigned, unsigned, int &, int &, int &) const override;
  void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
                    DebugLoc DL, unsigned DstReg, ArrayRef<MachineOperand> Cond,
                    unsigned TrueReg, unsigned FalseReg) const override;

  void copyPhysReg(MachineBasicBlock &MBB,
                   MachineBasicBlock::iterator I, DebugLoc DL,
                   unsigned DestReg, unsigned SrcReg,
                   bool KillSrc) const override;

  void storeRegToStackSlot(MachineBasicBlock &MBB,
                           MachineBasicBlock::iterator MBBI,
                           unsigned SrcReg, bool isKill, int FrameIndex,
                           const TargetRegisterClass *RC,
                           const TargetRegisterInfo *TRI) const override;

  void loadRegFromStackSlot(MachineBasicBlock &MBB,
                            MachineBasicBlock::iterator MBBI,
                            unsigned DestReg, int FrameIndex,
                            const TargetRegisterClass *RC,
                            const TargetRegisterInfo *TRI) const override;

  bool
  ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;

  bool FoldImmediate(MachineInstr *UseMI, MachineInstr *DefMI,
                     unsigned Reg, MachineRegisterInfo *MRI) const override;

  // If conversion by predication (only supported by some branch instructions).
  // All of the profitability checks always return true; it is always
  // profitable to use the predicated branches.
  bool isProfitableToIfCvt(MachineBasicBlock &MBB,
                          unsigned NumCycles, unsigned ExtraPredCycles,
                          BranchProbability Probability) const override {
    return true;
  }

  bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
                           unsigned NumT, unsigned ExtraT,
                           MachineBasicBlock &FMBB,
                           unsigned NumF, unsigned ExtraF,
                           BranchProbability Probability) const override;

  bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
                                 BranchProbability Probability) const override {
    return true;
  }

  bool isProfitableToUnpredicate(MachineBasicBlock &TMBB,
                                 MachineBasicBlock &FMBB) const override {
    return false;
  }

  // Predication support.
  bool isPredicated(const MachineInstr *MI) const override;

  bool isUnpredicatedTerminator(const MachineInstr *MI) const override;

  bool PredicateInstruction(MachineInstr *MI,
                            ArrayRef<MachineOperand> Pred) const override;

  bool SubsumesPredicate(ArrayRef<MachineOperand> Pred1,
                         ArrayRef<MachineOperand> Pred2) const override;

  bool DefinesPredicate(MachineInstr *MI,
                        std::vector<MachineOperand> &Pred) const override;

  bool isPredicable(MachineInstr *MI) const override;

  // Comparison optimization.


  bool analyzeCompare(const MachineInstr *MI,
                      unsigned &SrcReg, unsigned &SrcReg2,
                      int &Mask, int &Value) const override;

  bool optimizeCompareInstr(MachineInstr *CmpInstr,
                            unsigned SrcReg, unsigned SrcReg2,
                            int Mask, int Value,
                            const MachineRegisterInfo *MRI) const override;

  /// GetInstSize - Return the number of bytes of code the specified
  /// instruction may be.  This returns the maximum number of bytes.
  ///
  unsigned GetInstSizeInBytes(const MachineInstr *MI) const;

  void getNoopForMachoTarget(MCInst &NopInst) const override;

  std::pair<unsigned, unsigned>
  decomposeMachineOperandsTargetFlags(unsigned TF) const override;

  ArrayRef<std::pair<unsigned, const char *>>
  getSerializableDirectMachineOperandTargetFlags() const override;

  ArrayRef<std::pair<unsigned, const char *>>
  getSerializableBitmaskMachineOperandTargetFlags() const override;
};

}

#endif