1 //===-- X86RegisterInfo.h - X86 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 X86 implementation of the TargetRegisterInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_X86_X86REGISTERINFO_H
15 #define LLVM_LIB_TARGET_X86_X86REGISTERINFO_H
16 
17 #include "llvm/Target/TargetRegisterInfo.h"
18 
19 #define GET_REGINFO_HEADER
20 #include "X86GenRegisterInfo.inc"
21 
22 namespace llvm {
23   class Triple;
24 
25 class X86RegisterInfo final : public X86GenRegisterInfo {
26 private:
27   /// Is64Bit - Is the target 64-bits.
28   ///
29   bool Is64Bit;
30 
31   /// IsWin64 - Is the target on of win64 flavours
32   ///
33   bool IsWin64;
34 
35   /// SlotSize - Stack slot size in bytes.
36   ///
37   unsigned SlotSize;
38 
39   /// StackPtr - X86 physical register used as stack ptr.
40   ///
41   unsigned StackPtr;
42 
43   /// FramePtr - X86 physical register used as frame ptr.
44   ///
45   unsigned FramePtr;
46 
47   /// BasePtr - X86 physical register used as a base ptr in complex stack
48   /// frames. I.e., when we need a 3rd base, not just SP and FP, due to
49   /// variable size stack objects.
50   unsigned BasePtr;
51 
52 public:
53   X86RegisterInfo(const Triple &TT);
54 
55   // FIXME: This should be tablegen'd like getDwarfRegNum is
56   int getSEHRegNum(unsigned i) const;
57 
58   /// Code Generation virtual methods...
59   ///
60   bool trackLivenessAfterRegAlloc(const MachineFunction &MF) const override;
61 
62   /// getMatchingSuperRegClass - Return a subclass of the specified register
63   /// class A so that each register in it has a sub-register of the
64   /// specified sub-register index which is in the specified register class B.
65   const TargetRegisterClass *
66   getMatchingSuperRegClass(const TargetRegisterClass *A,
67                            const TargetRegisterClass *B,
68                            unsigned Idx) const override;
69 
70   const TargetRegisterClass *
71   getSubClassWithSubReg(const TargetRegisterClass *RC,
72                         unsigned Idx) const override;
73 
74   const TargetRegisterClass *
75   getLargestLegalSuperClass(const TargetRegisterClass *RC,
76                             const MachineFunction &MF) const override;
77 
78   /// getPointerRegClass - Returns a TargetRegisterClass used for pointer
79   /// values.
80   const TargetRegisterClass *
81   getPointerRegClass(const MachineFunction &MF,
82                      unsigned Kind = 0) const override;
83 
84   /// getCrossCopyRegClass - Returns a legal register class to copy a register
85   /// in the specified class to or from. Returns NULL if it is possible to copy
86   /// between a two registers of the specified class.
87   const TargetRegisterClass *
88   getCrossCopyRegClass(const TargetRegisterClass *RC) const override;
89 
90   /// getGPRsForTailCall - Returns a register class with registers that can be
91   /// used in forming tail calls.
92   const TargetRegisterClass *
93   getGPRsForTailCall(const MachineFunction &MF) const;
94 
95   unsigned getRegPressureLimit(const TargetRegisterClass *RC,
96                                MachineFunction &MF) const override;
97 
98   /// getCalleeSavedRegs - Return a null-terminated list of all of the
99   /// callee-save registers on this target.
100   const MCPhysReg *
101   getCalleeSavedRegs(const MachineFunction* MF) const override;
102   const uint32_t *getCallPreservedMask(const MachineFunction &MF,
103                                        CallingConv::ID) const override;
104   const uint32_t *getNoPreservedMask() const override;
105 
106   // Calls involved in thread-local variable lookup save more registers than
107   // normal calls, so they need a different mask to represent this.
108   const uint32_t *getDarwinTLSCallPreservedMask() const;
109 
110   /// getReservedRegs - Returns a bitset indexed by physical register number
111   /// indicating if a register is a special register that has particular uses and
112   /// should be considered unavailable at all times, e.g. SP, RA. This is used by
113   /// register scavenger to determine what registers are free.
114   BitVector getReservedRegs(const MachineFunction &MF) const override;
115 
116   void adjustStackMapLiveOutMask(uint32_t *Mask) const override;
117 
118   bool hasBasePointer(const MachineFunction &MF) const;
119 
120   bool canRealignStack(const MachineFunction &MF) const override;
121 
122   bool hasReservedSpillSlot(const MachineFunction &MF, unsigned Reg,
123                             int &FrameIdx) const override;
124 
125   void eliminateFrameIndex(MachineBasicBlock::iterator MI,
126                            int SPAdj, unsigned FIOperandNum,
127                            RegScavenger *RS = nullptr) const override;
128 
129   // Debug information queries.
130   unsigned getFrameRegister(const MachineFunction &MF) const override;
131   unsigned getPtrSizedFrameRegister(const MachineFunction &MF) const;
getStackRegister()132   unsigned getStackRegister() const { return StackPtr; }
getBaseRegister()133   unsigned getBaseRegister() const { return BasePtr; }
134   // FIXME: Move to FrameInfok
getSlotSize()135   unsigned getSlotSize() const { return SlotSize; }
136 };
137 
138 /// Returns the sub or super register of a specific X86 register.
139 /// e.g. getX86SubSuperRegister(X86::EAX, MVT::i16) returns X86::AX.
140 /// Aborts on error.
141 unsigned getX86SubSuperRegister(unsigned, MVT::SimpleValueType, bool High=false);
142 
143 /// Returns the sub or super register of a specific X86 register.
144 /// Like getX86SubSuperRegister() but returns 0 on error.
145 unsigned getX86SubSuperRegisterOrZero(unsigned, MVT::SimpleValueType,
146                                       bool High = false);
147 
148 //get512BitRegister - X86 utility - returns 512-bit super register
149 unsigned get512BitSuperRegister(unsigned Reg);
150 
151 } // End llvm namespace
152 
153 #endif
154