xref: /freebsd/contrib/llvm-project/llvm/lib/Target/AArch64/AArch64RegisterInfo.h (revision 5ffd83dbcc34f10e07f6d3e968ae6365869615f4)
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
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   /// Code Generation virtual methods...
46   const MCPhysReg *getCalleeSavedRegs(const MachineFunction *MF) const override;
47   const MCPhysReg *getDarwinCalleeSavedRegs(const MachineFunction *MF) const;
48   const MCPhysReg *
49   getCalleeSavedRegsViaCopy(const MachineFunction *MF) const;
50   const uint32_t *getCallPreservedMask(const MachineFunction &MF,
51                                        CallingConv::ID) const override;
52   const uint32_t *getDarwinCallPreservedMask(const MachineFunction &MF,
53                                              CallingConv::ID) const;
54 
55   unsigned getCSRFirstUseCost() const override {
56     // The cost will be compared against BlockFrequency where entry has the
57     // value of 1 << 14. A value of 5 will choose to spill or split really
58     // cold path instead of using a callee-saved register.
59     return 5;
60   }
61 
62   const TargetRegisterClass *
63   getSubClassWithSubReg(const TargetRegisterClass *RC,
64                         unsigned Idx) const override;
65 
66   // Calls involved in thread-local variable lookup save more registers than
67   // normal calls, so they need a different mask to represent this.
68   const uint32_t *getTLSCallPreservedMask() const;
69 
70   // Funclets on ARM64 Windows don't preserve any registers.
71   const uint32_t *getNoPreservedMask() const override;
72 
73   /// getThisReturnPreservedMask - Returns a call preserved mask specific to the
74   /// case that 'returned' is on an i64 first argument if the calling convention
75   /// is one that can (partially) model this attribute with a preserved mask
76   /// (i.e. it is a calling convention that uses the same register for the first
77   /// i64 argument and an i64 return value)
78   ///
79   /// Should return NULL in the case that the calling convention does not have
80   /// this property
81   const uint32_t *getThisReturnPreservedMask(const MachineFunction &MF,
82                                              CallingConv::ID) const;
83 
84   /// Stack probing calls preserve different CSRs to the normal CC.
85   const uint32_t *getWindowsStackProbePreservedMask() const;
86 
87   BitVector getReservedRegs(const MachineFunction &MF) const override;
88   bool isAsmClobberable(const MachineFunction &MF,
89                        MCRegister PhysReg) const override;
90   bool isConstantPhysReg(MCRegister PhysReg) const override;
91   const TargetRegisterClass *
92   getPointerRegClass(const MachineFunction &MF,
93                      unsigned Kind = 0) const override;
94   const TargetRegisterClass *
95   getCrossCopyRegClass(const TargetRegisterClass *RC) const override;
96 
97   bool requiresRegisterScavenging(const MachineFunction &MF) const override;
98   bool useFPForScavengingIndex(const MachineFunction &MF) const override;
99   bool requiresFrameIndexScavenging(const MachineFunction &MF) const override;
100 
101   bool needsFrameBaseReg(MachineInstr *MI, int64_t Offset) const override;
102   bool isFrameOffsetLegal(const MachineInstr *MI, Register BaseReg,
103                           int64_t Offset) const override;
104   void materializeFrameBaseRegister(MachineBasicBlock *MBB, Register BaseReg,
105                                     int FrameIdx,
106                                     int64_t Offset) const override;
107   void resolveFrameIndex(MachineInstr &MI, Register BaseReg,
108                          int64_t Offset) const override;
109   void eliminateFrameIndex(MachineBasicBlock::iterator II, int SPAdj,
110                            unsigned FIOperandNum,
111                            RegScavenger *RS = nullptr) const override;
112   bool cannotEliminateFrame(const MachineFunction &MF) const;
113 
114   bool requiresVirtualBaseRegisters(const MachineFunction &MF) const override;
115   bool hasBasePointer(const MachineFunction &MF) const;
116   unsigned getBaseRegister() const;
117 
118   // Debug information queries.
119   Register getFrameRegister(const MachineFunction &MF) const override;
120 
121   unsigned getRegPressureLimit(const TargetRegisterClass *RC,
122                                MachineFunction &MF) const override;
123 
124   unsigned getLocalAddressRegister(const MachineFunction &MF) const;
125 };
126 
127 } // end namespace llvm
128 
129 #endif
130