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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 "MCTargetDesc/MipsMCTargetDesc.h"
22 #include "Mips.h"
23 #include "MipsRegisterInfo.h"
24 #include "llvm/ADT/ArrayRef.h"
25 #include "llvm/CodeGen/MachineBasicBlock.h"
26 #include "llvm/CodeGen/MachineInstrBuilder.h"
27 #include "llvm/CodeGen/MachineMemOperand.h"
28 #include "llvm/CodeGen/TargetInstrInfo.h"
29 #include <cstdint>
30 
31 #define GET_INSTRINFO_HEADER
32 #include "MipsGenInstrInfo.inc"
33 
34 namespace llvm {
35 
36 class MachineInstr;
37 class MachineOperand;
38 class MipsSubtarget;
39 class TargetRegisterClass;
40 class TargetRegisterInfo;
41 
42 class MipsInstrInfo : public MipsGenInstrInfo {
43   virtual void anchor();
44 
45 protected:
46   const MipsSubtarget &Subtarget;
47   unsigned UncondBrOpc;
48 
49 public:
50   enum BranchType {
51     BT_None,       // Couldn't analyze branch.
52     BT_NoBranch,   // No branches found.
53     BT_Uncond,     // One unconditional branch.
54     BT_Cond,       // One conditional branch.
55     BT_CondUncond, // A conditional branch followed by an unconditional branch.
56     BT_Indirect    // One indirct branch.
57   };
58 
59   explicit MipsInstrInfo(const MipsSubtarget &STI, unsigned UncondBrOpc);
60 
61   static const MipsInstrInfo *create(MipsSubtarget &STI);
62 
63   /// Branch Analysis
64   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
65                      MachineBasicBlock *&FBB,
66                      SmallVectorImpl<MachineOperand> &Cond,
67                      bool AllowModify) const override;
68 
69   unsigned removeBranch(MachineBasicBlock &MBB,
70                         int *BytesRemoved = nullptr) const override;
71 
72   unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
73                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
74                         const DebugLoc &DL,
75                         int *BytesAdded = nullptr) const override;
76 
77   bool
78   reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const override;
79 
80   BranchType analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
81                            MachineBasicBlock *&FBB,
82                            SmallVectorImpl<MachineOperand> &Cond,
83                            bool AllowModify,
84                            SmallVectorImpl<MachineInstr *> &BranchInstrs) const;
85 
86   /// Determine the opcode of a non-delay slot form for a branch if one exists.
87   unsigned getEquivalentCompactForm(const MachineBasicBlock::iterator I) const;
88 
89   /// Determine if the branch target is in range.
90   bool isBranchOffsetInRange(unsigned BranchOpc,
91                              int64_t BrOffset) const override;
92 
93   /// Predicate to determine if an instruction can go in a forbidden slot.
94   bool SafeInForbiddenSlot(const MachineInstr &MI) const;
95 
96   /// Predicate to determine if an instruction has a forbidden slot.
97   bool HasForbiddenSlot(const MachineInstr &MI) const;
98 
99   /// Insert nop instruction when hazard condition is found
100   void insertNoop(MachineBasicBlock &MBB,
101                   MachineBasicBlock::iterator MI) const override;
102 
103   /// getRegisterInfo - TargetInstrInfo is a superset of MRegister info.  As
104   /// such, whenever a client has an instance of instruction info, it should
105   /// always be able to get register info as well (through this method).
106   virtual const MipsRegisterInfo &getRegisterInfo() const = 0;
107 
108   virtual unsigned getOppositeBranchOpc(unsigned Opc) const = 0;
109 
110   /// Return the number of bytes of code the specified instruction may be.
111   unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
112 
storeRegToStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,unsigned SrcReg,bool isKill,int FrameIndex,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI)113   void storeRegToStackSlot(MachineBasicBlock &MBB,
114                            MachineBasicBlock::iterator MBBI,
115                            unsigned SrcReg, bool isKill, int FrameIndex,
116                            const TargetRegisterClass *RC,
117                            const TargetRegisterInfo *TRI) const override {
118     storeRegToStack(MBB, MBBI, SrcReg, isKill, FrameIndex, RC, TRI, 0);
119   }
120 
loadRegFromStackSlot(MachineBasicBlock & MBB,MachineBasicBlock::iterator MBBI,unsigned DestReg,int FrameIndex,const TargetRegisterClass * RC,const TargetRegisterInfo * TRI)121   void loadRegFromStackSlot(MachineBasicBlock &MBB,
122                             MachineBasicBlock::iterator MBBI,
123                             unsigned DestReg, int FrameIndex,
124                             const TargetRegisterClass *RC,
125                             const TargetRegisterInfo *TRI) const override {
126     loadRegFromStack(MBB, MBBI, DestReg, FrameIndex, RC, TRI, 0);
127   }
128 
129   virtual void storeRegToStack(MachineBasicBlock &MBB,
130                                MachineBasicBlock::iterator MI,
131                                unsigned SrcReg, bool isKill, int FrameIndex,
132                                const TargetRegisterClass *RC,
133                                const TargetRegisterInfo *TRI,
134                                int64_t Offset) const = 0;
135 
136   virtual void loadRegFromStack(MachineBasicBlock &MBB,
137                                 MachineBasicBlock::iterator MI,
138                                 unsigned DestReg, int FrameIndex,
139                                 const TargetRegisterClass *RC,
140                                 const TargetRegisterInfo *TRI,
141                                 int64_t Offset) const = 0;
142 
143   virtual void adjustStackPtr(unsigned SP, int64_t Amount,
144                               MachineBasicBlock &MBB,
145                               MachineBasicBlock::iterator I) const = 0;
146 
147   /// Create an instruction which has the same operands and memory operands
148   /// as MI but has a new opcode.
149   MachineInstrBuilder genInstrWithNewOpc(unsigned NewOpc,
150                                          MachineBasicBlock::iterator I) const;
151 
152   bool findCommutedOpIndices(MachineInstr &MI, unsigned &SrcOpIdx1,
153                              unsigned &SrcOpIdx2) const override;
154 
155   /// Perform target specific instruction verification.
156   bool verifyInstruction(const MachineInstr &MI,
157                          StringRef &ErrInfo) const override;
158 
159   std::pair<unsigned, unsigned>
160   decomposeMachineOperandsTargetFlags(unsigned TF) const override;
161 
162   ArrayRef<std::pair<unsigned, const char *>>
163   getSerializableDirectMachineOperandTargetFlags() const override;
164 
165 protected:
166   bool isZeroImm(const MachineOperand &op) const;
167 
168   MachineMemOperand *GetMemOperand(MachineBasicBlock &MBB, int FI,
169                                    MachineMemOperand::Flags Flags) const;
170 
171 private:
172   virtual unsigned getAnalyzableBrOpc(unsigned Opc) const = 0;
173 
174   void AnalyzeCondBr(const MachineInstr *Inst, unsigned Opc,
175                      MachineBasicBlock *&BB,
176                      SmallVectorImpl<MachineOperand> &Cond) const;
177 
178   void BuildCondBr(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
179                    const DebugLoc &DL, ArrayRef<MachineOperand> Cond) const;
180 };
181 
182 /// Create MipsInstrInfo objects.
183 const MipsInstrInfo *createMips16InstrInfo(const MipsSubtarget &STI);
184 const MipsInstrInfo *createMipsSEInstrInfo(const MipsSubtarget &STI);
185 
186 } // end namespace llvm
187 
188 #endif // LLVM_LIB_TARGET_MIPS_MIPSINSTRINFO_H
189