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1 //==- AArch64RegisterInfo.h - AArch64 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 AArch64 implementation of the MRegisterInfo class.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64REGISTERINFO_H
14 #define LLVM_LIB_TARGET_AARCH64_AARCH64REGISTERINFO_H
15 
16 #define GET_REGINFO_HEADER
17 #include "AArch64GenRegisterInfo.inc"
18 
19 namespace llvm {
20 
21 class MachineFunction;
22 class RegScavenger;
23 class TargetRegisterClass;
24 class Triple;
25 
26 class AArch64RegisterInfo final : public AArch64GenRegisterInfo {
27   const Triple &TT;
28 
29 public:
30   AArch64RegisterInfo(const Triple &TT);
31 
32   // FIXME: This should be tablegen'd like getDwarfRegNum is
getSEHRegNum(unsigned i)33   int getSEHRegNum(unsigned i) const {
34     return getEncodingValue(i);
35   }
36 
37   bool isReservedReg(const MachineFunction &MF, MCRegister Reg) const;
38   bool isAnyArgRegReserved(const MachineFunction &MF) const;
39   void emitReservedArgRegCallError(const MachineFunction &MF) const;
40 
41   void UpdateCustomCalleeSavedRegs(MachineFunction &MF) const;
42   void UpdateCustomCallPreservedMask(MachineFunction &MF,
43                                      const uint32_t **Mask) const;
44 
45   static bool hasSVEArgsOrReturn(const MachineFunction *MF);
46 
47   /// Code Generation virtual methods...
48   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
49   const MCPhysReg *getDarwinCalleeSavedRegs(const MachineFunction *MF) const;
50   const MCPhysReg *
51   getCalleeSavedRegsViaCopy(const MachineFunction *MF) const;
52   const uint32_t *getCallPreservedMask(const MachineFunction &MF,
53                                        CallingConv::ID) const override;
54   const uint32_t *getDarwinCallPreservedMask(const MachineFunction &MF,
55                                              CallingConv::ID) const;
56 
getCSRFirstUseCost()57   unsigned getCSRFirstUseCost() const override {
58     // The cost will be compared against BlockFrequency where entry has the
59     // value of 1 << 14. A value of 5 will choose to spill or split really
60     // cold path instead of using a callee-saved register.
61     return 5;
62   }
63 
64   const TargetRegisterClass *
65   getSubClassWithSubReg(const TargetRegisterClass *RC,
66                         unsigned Idx) const override;
67 
68   // Calls involved in thread-local variable lookup save more registers than
69   // normal calls, so they need a different mask to represent this.
70   const uint32_t *getTLSCallPreservedMask() const;
71 
72   // Funclets on ARM64 Windows don't preserve any registers.
73   const uint32_t *getNoPreservedMask() const override;
74 
75   // Unwinders may not preserve all Neon and SVE registers.
76   const uint32_t *
77   getCustomEHPadPreservedMask(const MachineFunction &MF) const override;
78 
79   /// getThisReturnPreservedMask - Returns a call preserved mask specific to the
80   /// case that 'returned' is on an i64 first argument if the calling convention
81   /// is one that can (partially) model this attribute with a preserved mask
82   /// (i.e. it is a calling convention that uses the same register for the first
83   /// i64 argument and an i64 return value)
84   ///
85   /// Should return NULL in the case that the calling convention does not have
86   /// this property
87   const uint32_t *getThisReturnPreservedMask(const MachineFunction &MF,
88                                              CallingConv::ID) const;
89 
90   /// Stack probing calls preserve different CSRs to the normal CC.
91   const uint32_t *getWindowsStackProbePreservedMask() const;
92 
93   BitVector getReservedRegs(const MachineFunction &MF) const override;
94   bool isAsmClobberable(const MachineFunction &MF,
95                        MCRegister PhysReg) const override;
96   bool isConstantPhysReg(MCRegister PhysReg) const override;
97   const TargetRegisterClass *
98   getPointerRegClass(const MachineFunction &MF,
99                      unsigned Kind = 0) const override;
100   const TargetRegisterClass *
101   getCrossCopyRegClass(const TargetRegisterClass *RC) const override;
102 
103   bool requiresRegisterScavenging(const MachineFunction &MF) const override;
104   bool useFPForScavengingIndex(const MachineFunction &MF) const override;
105   bool requiresFrameIndexScavenging(const MachineFunction &MF) const override;
106 
107   bool needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const override;
108   bool isFrameOffsetLegal(const MachineInstr *MI, Register BaseReg,
109                           int64_t Offset) const override;
110   void materializeFrameBaseRegister(MachineBasicBlock *MBB, Register BaseReg,
111                                     int FrameIdx,
112                                     int64_t Offset) const override;
113   void resolveFrameIndex(MachineInstr &MI, Register BaseReg,
114                          int64_t Offset) const override;
115   void eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
116                            unsigned FIOperandNum,
117                            RegScavenger *RS = nullptr) const override;
118   bool cannotEliminateFrame(const MachineFunction &MF) const;
119 
120   bool requiresVirtualBaseRegisters(const MachineFunction &MF) const override;
121   bool hasBasePointer(const MachineFunction &MF) const;
122   unsigned getBaseRegister() const;
123 
124   // Debug information queries.
125   Register getFrameRegister(const MachineFunction &MF) const override;
126 
127   unsigned getRegPressureLimit(const TargetRegisterClass *RC,
128                                MachineFunction &MF) const override;
129 
130   unsigned getLocalAddressRegister(const MachineFunction &MF) const;
131   bool regNeedsCFI(unsigned Reg, unsigned &RegToUseForCFI) const;
132 
133   /// SrcRC and DstRC will be morphed into NewRC if this returns true
134   bool shouldCoalesce(MachineInstr *MI, const TargetRegisterClass *SrcRC,
135                       unsigned SubReg, const TargetRegisterClass *DstRC,
136                       unsigned DstSubReg, const TargetRegisterClass *NewRC,
137                       LiveIntervals &LIS) const override;
138 };
139 
140 } // end namespace llvm
141 
142 #endif
143