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1 //===-- ARMBaseRegisterInfo.h - ARM Register Information Impl ---*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file contains the base ARM implementation of TargetRegisterInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_ARM_ARMBASEREGISTERINFO_H
15 #define LLVM_LIB_TARGET_ARM_ARMBASEREGISTERINFO_H
16 
17 #include "MCTargetDesc/ARMBaseInfo.h"
18 #include "llvm/CodeGen/MachineBasicBlock.h"
19 #include "llvm/CodeGen/MachineInstr.h"
20 #include "llvm/CodeGen/TargetRegisterInfo.h"
21 #include "llvm/IR/CallingConv.h"
22 #include "llvm/MC/MCRegisterInfo.h"
23 #include <cstdint>
24 
25 #define GET_REGINFO_HEADER
26 #include "ARMGenRegisterInfo.inc"
27 
28 namespace llvm {
29 
30 class LiveIntervals;
31 
32 /// Register allocation hints.
33 namespace ARMRI {
34 
35   enum {
36     RegPairOdd  = 1,
37     RegPairEven = 2
38   };
39 
40 } // end namespace ARMRI
41 
42 /// isARMArea1Register - Returns true if the register is a low register (r0-r7)
43 /// or a stack/pc register that we should push/pop.
isARMArea1Register(unsigned Reg,bool isIOS)44 static inline bool isARMArea1Register(unsigned Reg, bool isIOS) {
45   using namespace ARM;
46 
47   switch (Reg) {
48     case R0:  case R1:  case R2:  case R3:
49     case R4:  case R5:  case R6:  case R7:
50     case LR:  case SP:  case PC:
51       return true;
52     case R8:  case R9:  case R10: case R11: case R12:
53       // For iOS we want r7 and lr to be next to each other.
54       return !isIOS;
55     default:
56       return false;
57   }
58 }
59 
isARMArea2Register(unsigned Reg,bool isIOS)60 static inline bool isARMArea2Register(unsigned Reg, bool isIOS) {
61   using namespace ARM;
62 
63   switch (Reg) {
64     case R8: case R9: case R10: case R11: case R12:
65       // iOS has this second area.
66       return isIOS;
67     default:
68       return false;
69   }
70 }
71 
isARMArea3Register(unsigned Reg,bool isIOS)72 static inline bool isARMArea3Register(unsigned Reg, bool isIOS) {
73   using namespace ARM;
74 
75   switch (Reg) {
76     case D15: case D14: case D13: case D12:
77     case D11: case D10: case D9:  case D8:
78     case D7:  case D6:  case D5:  case D4:
79     case D3:  case D2:  case D1:  case D0:
80     case D31: case D30: case D29: case D28:
81     case D27: case D26: case D25: case D24:
82     case D23: case D22: case D21: case D20:
83     case D19: case D18: case D17: case D16:
84       return true;
85     default:
86       return false;
87   }
88 }
89 
isCalleeSavedRegister(unsigned Reg,const MCPhysReg * CSRegs)90 static inline bool isCalleeSavedRegister(unsigned Reg,
91                                          const MCPhysReg *CSRegs) {
92   for (unsigned i = 0; CSRegs[i]; ++i)
93     if (Reg == CSRegs[i])
94       return true;
95   return false;
96 }
97 
98 class ARMBaseRegisterInfo : public ARMGenRegisterInfo {
99 protected:
100   /// BasePtr - ARM physical register used as a base ptr in complex stack
101   /// frames. I.e., when we need a 3rd base, not just SP and FP, due to
102   /// variable size stack objects.
103   unsigned BasePtr = ARM::R6;
104 
105   // Can be only subclassed.
106   explicit ARMBaseRegisterInfo();
107 
108   // Return the opcode that implements 'Op', or 0 if no opcode
109   unsigned getOpcode(int Op) const;
110 
111 public:
112   /// Code Generation virtual methods...
113   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
114   const MCPhysReg *
115   getCalleeSavedRegsViaCopy(const MachineFunction *MF) const;
116   const uint32_t *getCallPreservedMask(const MachineFunction &MF,
117                                        CallingConv::ID) const override;
118   const uint32_t *getNoPreservedMask() const override;
119   const uint32_t *getTLSCallPreservedMask(const MachineFunction &MF) const;
120   const uint32_t *getSjLjDispatchPreservedMask(const MachineFunction &MF) const;
121 
122   /// getThisReturnPreservedMask - Returns a call preserved mask specific to the
123   /// case that 'returned' is on an i32 first argument if the calling convention
124   /// is one that can (partially) model this attribute with a preserved mask
125   /// (i.e. it is a calling convention that uses the same register for the first
126   /// i32 argument and an i32 return value)
127   ///
128   /// Should return NULL in the case that the calling convention does not have
129   /// this property
130   const uint32_t *getThisReturnPreservedMask(const MachineFunction &MF,
131                                              CallingConv::ID) const;
132 
133   BitVector getReservedRegs(const MachineFunction &MF) const override;
134 
135   const TargetRegisterClass *
136   getPointerRegClass(const MachineFunction &MF,
137                      unsigned Kind = 0) const override;
138   const TargetRegisterClass *
139   getCrossCopyRegClass(const TargetRegisterClass *RC) const override;
140 
141   const TargetRegisterClass *
142   getLargestLegalSuperClass(const TargetRegisterClass *RC,
143                             const MachineFunction &MF) const override;
144 
145   unsigned getRegPressureLimit(const TargetRegisterClass *RC,
146                                MachineFunction &MF) const override;
147 
148   bool getRegAllocationHints(unsigned VirtReg,
149                              ArrayRef<MCPhysReg> Order,
150                              SmallVectorImpl<MCPhysReg> &Hints,
151                              const MachineFunction &MF,
152                              const VirtRegMap *VRM,
153                              const LiveRegMatrix *Matrix) const override;
154 
155   void updateRegAllocHint(unsigned Reg, unsigned NewReg,
156                           MachineFunction &MF) const override;
enableMultipleCopyHints()157   bool enableMultipleCopyHints() const override { return true; }
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   unsigned getFrameRegister(const MachineFunction &MF) const override;
getBaseRegister()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
217