lib/Target/ARM/ARMBaseRegisterInfo.h

   1 //===-- ARMBaseRegisterInfo.h - ARM Register Information Impl ---*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains the base ARM implementation of TargetRegisterInfo class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #ifndef LLVM_LIB_TARGET_ARM_ARMBASEREGISTERINFO_H
  14 #define LLVM_LIB_TARGET_ARM_ARMBASEREGISTERINFO_H
  15
  16 #include "MCTargetDesc/ARMBaseInfo.h"
  17 #include "llvm/CodeGen/MachineBasicBlock.h"
  18 #include "llvm/CodeGen/MachineInstr.h"
  19 #include "llvm/CodeGen/TargetRegisterInfo.h"
  20 #include "llvm/IR/CallingConv.h"
  21 #include "llvm/MC/MCRegisterInfo.h"
  22 #include <cstdint>
  23
  24 #define GET_REGINFO_HEADER
  25 #include "ARMGenRegisterInfo.inc"
  26
  27 namespace llvm {
  28
  29 class LiveIntervals;
  30
  31 /// Register allocation hints.
  32 namespace ARMRI {
  33
  34   enum {
  35     RegPairOdd  = 1,
  36     RegPairEven = 2
  37   };
  38
  39 } // end namespace ARMRI
  40
  41 /// isARMArea1Register - Returns true if the register is a low register (r0-r7)
  42 /// or a stack/pc register that we should push/pop.
  43 static inline bool isARMArea1Register(unsigned Reg, bool isIOS) {
  44   using namespace ARM;
  45
  46   switch (Reg) {
  47     case R0:  case R1:  case R2:  case R3:
  48     case R4:  case R5:  case R6:  case R7:
  49     case LR:  case SP:  case PC:
  50       return true;
  51     case R8:  case R9:  case R10: case R11: case R12:
  52       // For iOS we want r7 and lr to be next to each other.
  53       return !isIOS;
  54     default:
  55       return false;
  56   }
  57 }
  58
  59 static inline bool isARMArea2Register(unsigned Reg, bool isIOS) {
  60   using namespace ARM;
  61
  62   switch (Reg) {
  63     case R8: case R9: case R10: case R11: case R12:
  64       // iOS has this second area.
  65       return isIOS;
  66     default:
  67       return false;
  68   }
  69 }
  70
  71 static inline bool isARMArea3Register(unsigned Reg, bool isIOS) {
  72   using namespace ARM;
  73
  74   switch (Reg) {
  75     case D15: case D14: case D13: case D12:
  76     case D11: case D10: case D9:  case D8:
  77     case D7:  case D6:  case D5:  case D4:
  78     case D3:  case D2:  case D1:  case D0:
  79     case D31: case D30: case D29: case D28:
  80     case D27: case D26: case D25: case D24:
  81     case D23: case D22: case D21: case D20:
  82     case D19: case D18: case D17: case D16:
  83       return true;
  84     default:
  85       return false;
  86   }
  87 }
  88
  89 static inline bool isCalleeSavedRegister(unsigned Reg,
  90                                          const MCPhysReg *CSRegs) {
  91   for (unsigned i = 0; CSRegs[i]; ++i)
  92     if (Reg == CSRegs[i])
  93       return true;
  94   return false;
  95 }
  96
  97 class ARMBaseRegisterInfo : public ARMGenRegisterInfo {
  98 protected:
  99   /// BasePtr - ARM physical register used as a base ptr in complex stack
 100   /// frames. I.e., when we need a 3rd base, not just SP and FP, due to
 101   /// variable size stack objects.
 102   unsigned BasePtr = ARM::R6;
 103
 104   // Can be only subclassed.
 105   explicit ARMBaseRegisterInfo();
 106
 107   // Return the opcode that implements 'Op', or 0 if no opcode
 108   unsigned getOpcode(int Op) const;
 109
 110 public:
 111   /// Code Generation virtual methods...
 112   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
 113   const MCPhysReg *
 114   getCalleeSavedRegsViaCopy(const MachineFunction *MF) const;
 115   const uint32_t *getCallPreservedMask(const MachineFunction &MF,
 116                                        CallingConv::ID) const override;
 117   const uint32_t *getNoPreservedMask() const override;
 118   const uint32_t *getTLSCallPreservedMask(const MachineFunction &MF) const;
 119   const uint32_t *getSjLjDispatchPreservedMask(const MachineFunction &MF) const;
 120
 121   /// getThisReturnPreservedMask - Returns a call preserved mask specific to the
 122   /// case that 'returned' is on an i32 first argument if the calling convention
 123   /// is one that can (partially) model this attribute with a preserved mask
 124   /// (i.e. it is a calling convention that uses the same register for the first
 125   /// i32 argument and an i32 return value)
 126   ///
 127   /// Should return NULL in the case that the calling convention does not have
 128   /// this property
 129   const uint32_t *getThisReturnPreservedMask(const MachineFunction &MF,
 130                                              CallingConv::ID) const;
 131
 132   BitVector getReservedRegs(const MachineFunction &MF) const override;
 133   bool isAsmClobberable(const MachineFunction &MF,
 134                        unsigned PhysReg) const override;
 135
 136   const TargetRegisterClass *
 137   getPointerRegClass(const MachineFunction &MF,
 138                      unsigned Kind = 0) const override;
 139   const TargetRegisterClass *
 140   getCrossCopyRegClass(const TargetRegisterClass *RC) const override;
 141
 142   const TargetRegisterClass *
 143   getLargestLegalSuperClass(const TargetRegisterClass *RC,
 144                             const MachineFunction &MF) const override;
 145
 146   unsigned getRegPressureLimit(const TargetRegisterClass *RC,
 147                                MachineFunction &MF) const override;
 148
 149   bool getRegAllocationHints(unsigned VirtReg,
 150                              ArrayRef<MCPhysReg> Order,
 151                              SmallVectorImpl<MCPhysReg> &Hints,
 152                              const MachineFunction &MF,
 153                              const VirtRegMap *VRM,
 154                              const LiveRegMatrix *Matrix) const override;
 155
 156   void updateRegAllocHint(unsigned Reg, unsigned NewReg,
 157                           MachineFunction &MF) const override;
 158
 159   bool hasBasePointer(const MachineFunction &MF) const;
 160
 161   bool canRealignStack(const MachineFunction &MF) const override;
 162   int64_t getFrameIndexInstrOffset(const MachineInstr *MI,
 163                                    int Idx) const override;
 164   bool needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const override;
 165   void materializeFrameBaseRegister(MachineBasicBlock *MBB,
 166                                     unsigned BaseReg, int FrameIdx,
 167                                     int64_t Offset) const override;
 168   void resolveFrameIndex(MachineInstr &MI, unsigned BaseReg,
 169                          int64_t Offset) const override;
 170   bool isFrameOffsetLegal(const MachineInstr *MI, unsigned BaseReg,
 171                           int64_t Offset) const override;
 172
 173   bool cannotEliminateFrame(const MachineFunction &MF) const;
 174
 175   // Debug information queries.
 176   Register getFrameRegister(const MachineFunction &MF) const override;
 177   unsigned getBaseRegister() const { return BasePtr; }
 178
 179   bool isLowRegister(unsigned Reg) const;
 180
 181
 182   /// emitLoadConstPool - Emits a load from constpool to materialize the
 183   /// specified immediate.
 184   virtual void
 185   emitLoadConstPool(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
 186                     const DebugLoc &dl, unsigned DestReg, unsigned SubIdx,
 187                     int Val, ARMCC::CondCodes Pred = ARMCC::AL,
 188                     unsigned PredReg = 0,
 189                     unsigned MIFlags = MachineInstr::NoFlags) const;
 190
 191   /// Code Generation virtual methods...
 192   bool requiresRegisterScavenging(const MachineFunction &MF) const override;
 193
 194   bool trackLivenessAfterRegAlloc(const MachineFunction &MF) const override;
 195
 196   bool requiresFrameIndexScavenging(const MachineFunction &MF) const override;
 197
 198   bool requiresVirtualBaseRegisters(const MachineFunction &MF) const override;
 199
 200   void eliminateFrameIndex(MachineBasicBlock::iterator II,
 201                            int SPAdj, unsigned FIOperandNum,
 202                            RegScavenger *RS = nullptr) const override;
 203
 204   /// SrcRC and DstRC will be morphed into NewRC if this returns true
 205   bool shouldCoalesce(MachineInstr *MI,
 206                       const TargetRegisterClass *SrcRC,
 207                       unsigned SubReg,
 208                       const TargetRegisterClass *DstRC,
 209                       unsigned DstSubReg,
 210                       const TargetRegisterClass *NewRC,
 211                       LiveIntervals &LIS) const override;
 212 };
 213
 214 } // end namespace llvm
 215
 216 #endif // LLVM_LIB_TARGET_ARM_ARMBASEREGISTERINFO_H