1 //===-- MipsInstrInfo.h - Mips Instruction Information ----------*- 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 Mips implementation of the TargetInstrInfo class.
11 //
12 // FIXME: We need to override TargetInstrInfo::getInlineAsmLength method in
13 // order for MipsLongBranch pass to work correctly when the code has inline
14 // assembly.  The returned value doesn't have to be the asm instruction's exact
15 // size in bytes; MipsLongBranch only expects it to be the correct upper bound.
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_LIB_TARGET_MIPS_MIPSINSTRINFO_H
19 #define LLVM_LIB_TARGET_MIPS_MIPSINSTRINFO_H
20 
21 #include "Mips.h"
22 #include "MipsAnalyzeImmediate.h"
23 #include "MipsRegisterInfo.h"
24 #include "llvm/CodeGen/MachineInstrBuilder.h"
25 #include "llvm/Support/ErrorHandling.h"
26 #include "llvm/Target/TargetInstrInfo.h"
27 
28 #define GET_INSTRINFO_HEADER
29 #include "MipsGenInstrInfo.inc"
30 
31 namespace llvm {
32 class MipsSubtarget;
33 class MipsInstrInfo : public MipsGenInstrInfo {
34   virtual void anchor();
35 protected:
36   const MipsSubtarget &Subtarget;
37   unsigned UncondBrOpc;
38 
39 public:
40   enum BranchType {
41     BT_None,       // Couldn't analyze branch.
42     BT_NoBranch,   // No branches found.
43     BT_Uncond,     // One unconditional branch.
44     BT_Cond,       // One conditional branch.
45     BT_CondUncond, // A conditional branch followed by an unconditional branch.
46     BT_Indirect    // One indirct branch.
47   };
48 
49   explicit MipsInstrInfo(const MipsSubtarget &STI, unsigned UncondBrOpc);
50 
51   static const MipsInstrInfo *create(MipsSubtarget &STI);
52 
53   /// Branch Analysis
54   bool AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
55                      MachineBasicBlock *&FBB,
56                      SmallVectorImpl<MachineOperand> &Cond,
57                      bool AllowModify) const override;
58 
59   unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
60 
61   unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
62                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
63                         DebugLoc DL) const override;
64 
65   bool
66   ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
67 
68   BranchType AnalyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
69                            MachineBasicBlock *&FBB,
70                            SmallVectorImpl<MachineOperand> &Cond,
71                            bool AllowModify,
72                            SmallVectorImpl<MachineInstr*> &BranchInstrs) const;
73 
74   /// Insert nop instruction when hazard condition is found
75   void insertNoop(MachineBasicBlock &MBB,
76                   MachineBasicBlock::iterator MI) const override;
77 
78   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
79   /// such, whenever a client has an instance of instruction info, it should
80   /// always be able to get register info as well (through this method).
81   ///
82   virtual const MipsRegisterInfo &getRegisterInfo() const = 0;
83 
84   virtual unsigned getOppositeBranchOpc(unsigned Opc) const = 0;
85 
86   /// Return the number of bytes of code the specified instruction may be.
87   unsigned GetInstSizeInBytes(const MachineInstr *MI) const;
88 
storeRegToStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,unsigned SrcReg,bool isKill,int FrameIndex,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI)89   void storeRegToStackSlot(MachineBasicBlock &MBB,
90                            MachineBasicBlock::iterator MBBI,
91                            unsigned SrcReg, bool isKill, int FrameIndex,
92                            const TargetRegisterClass *RC,
93                            const TargetRegisterInfo *TRI) const override {
94     storeRegToStack(MBB, MBBI, SrcReg, isKill, FrameIndex, RC, TRI, 0);
95   }
96 
loadRegFromStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,unsigned DestReg,int FrameIndex,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI)97   void loadRegFromStackSlot(MachineBasicBlock &MBB,
98                             MachineBasicBlock::iterator MBBI,
99                             unsigned DestReg, int FrameIndex,
100                             const TargetRegisterClass *RC,
101                             const TargetRegisterInfo *TRI) const override {
102     loadRegFromStack(MBB, MBBI, DestReg, FrameIndex, RC, TRI, 0);
103   }
104 
105   virtual void storeRegToStack(MachineBasicBlock &MBB,
106                                MachineBasicBlock::iterator MI,
107                                unsigned SrcReg, bool isKill, int FrameIndex,
108                                const TargetRegisterClass *RC,
109                                const TargetRegisterInfo *TRI,
110                                int64_t Offset) const = 0;
111 
112   virtual void loadRegFromStack(MachineBasicBlock &MBB,
113                                 MachineBasicBlock::iterator MI,
114                                 unsigned DestReg, int FrameIndex,
115                                 const TargetRegisterClass *RC,
116                                 const TargetRegisterInfo *TRI,
117                                 int64_t Offset) const = 0;
118 
119   virtual void adjustStackPtr(unsigned SP, int64_t Amount,
120                               MachineBasicBlock &MBB,
121                               MachineBasicBlock::iterator I) const = 0;
122 
123   /// Create an instruction which has the same operands and memory operands
124   /// as MI but has a new opcode.
125   MachineInstrBuilder genInstrWithNewOpc(unsigned NewOpc,
126                                          MachineBasicBlock::iterator I) const;
127 
128 protected:
129   bool isZeroImm(const MachineOperand &op) const;
130 
131   MachineMemOperand *GetMemOperand(MachineBasicBlock &MBB, int FI,
132                                    unsigned Flag) const;
133 
134 private:
135   virtual unsigned getAnalyzableBrOpc(unsigned Opc) const = 0;
136 
137   void AnalyzeCondBr(const MachineInstr *Inst, unsigned Opc,
138                      MachineBasicBlock *&BB,
139                      SmallVectorImpl<MachineOperand> &Cond) const;
140 
141   void BuildCondBr(MachineBasicBlock &MBB, MachineBasicBlock *TBB, DebugLoc DL,
142                    ArrayRef<MachineOperand> Cond) const;
143 };
144 
145 /// Create MipsInstrInfo objects.
146 const MipsInstrInfo *createMips16InstrInfo(const MipsSubtarget &STI);
147 const MipsInstrInfo *createMipsSEInstrInfo(const MipsSubtarget &STI);
148 
149 }
150 
151 #endif
152