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1 //===-- SystemZInstrInfo.h - SystemZ 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 SystemZ implementation of the TargetInstrInfo class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
15 #define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
16 
17 #include "SystemZ.h"
18 #include "SystemZRegisterInfo.h"
19 #include "llvm/Target/TargetInstrInfo.h"
20 
21 #define GET_INSTRINFO_HEADER
22 #include "SystemZGenInstrInfo.inc"
23 
24 namespace llvm {
25 
26 class SystemZTargetMachine;
27 
28 namespace SystemZII {
29 enum {
30   // See comments in SystemZInstrFormats.td.
31   SimpleBDXLoad          = (1 << 0),
32   SimpleBDXStore         = (1 << 1),
33   Has20BitOffset         = (1 << 2),
34   HasIndex               = (1 << 3),
35   Is128Bit               = (1 << 4),
36   AccessSizeMask         = (31 << 5),
37   AccessSizeShift        = 5,
38   CCValuesMask           = (15 << 10),
39   CCValuesShift          = 10,
40   CompareZeroCCMaskMask  = (15 << 14),
41   CompareZeroCCMaskShift = 14,
42   CCMaskFirst            = (1 << 18),
43   CCMaskLast             = (1 << 19),
44   IsLogical              = (1 << 20)
45 };
getAccessSize(unsigned int Flags)46 static inline unsigned getAccessSize(unsigned int Flags) {
47   return (Flags & AccessSizeMask) >> AccessSizeShift;
48 }
getCCValues(unsigned int Flags)49 static inline unsigned getCCValues(unsigned int Flags) {
50   return (Flags & CCValuesMask) >> CCValuesShift;
51 }
getCompareZeroCCMask(unsigned int Flags)52 static inline unsigned getCompareZeroCCMask(unsigned int Flags) {
53   return (Flags & CompareZeroCCMaskMask) >> CompareZeroCCMaskShift;
54 }
55 
56 // SystemZ MachineOperand target flags.
57 enum {
58   // Masks out the bits for the access model.
59   MO_SYMBOL_MODIFIER = (3 << 0),
60 
61   // @GOT (aka @GOTENT)
62   MO_GOT = (1 << 0),
63 
64   // @INDNTPOFF
65   MO_INDNTPOFF = (2 << 0)
66 };
67 // Classifies a branch.
68 enum BranchType {
69   // An instruction that branches on the current value of CC.
70   BranchNormal,
71 
72   // An instruction that peforms a 32-bit signed comparison and branches
73   // on the result.
74   BranchC,
75 
76   // An instruction that peforms a 32-bit unsigned comparison and branches
77   // on the result.
78   BranchCL,
79 
80   // An instruction that peforms a 64-bit signed comparison and branches
81   // on the result.
82   BranchCG,
83 
84   // An instruction that peforms a 64-bit unsigned comparison and branches
85   // on the result.
86   BranchCLG,
87 
88   // An instruction that decrements a 32-bit register and branches if
89   // the result is nonzero.
90   BranchCT,
91 
92   // An instruction that decrements a 64-bit register and branches if
93   // the result is nonzero.
94   BranchCTG
95 };
96 // Information about a branch instruction.
97 struct Branch {
98   // The type of the branch.
99   BranchType Type;
100 
101   // CCMASK_<N> is set if CC might be equal to N.
102   unsigned CCValid;
103 
104   // CCMASK_<N> is set if the branch should be taken when CC == N.
105   unsigned CCMask;
106 
107   // The target of the branch.
108   const MachineOperand *Target;
109 
BranchBranch110   Branch(BranchType type, unsigned ccValid, unsigned ccMask,
111          const MachineOperand *target)
112     : Type(type), CCValid(ccValid), CCMask(ccMask), Target(target) {}
113 };
114 // Kinds of fused compares in compare-and-* instructions.  Together with type
115 // of the converted compare, this identifies the compare-and-*
116 // instruction.
117 enum FusedCompareType {
118   // Relative branch - CRJ etc.
119   CompareAndBranch,
120 
121   // Indirect branch, used for return - CRBReturn etc.
122   CompareAndReturn,
123 
124   // Indirect branch, used for sibcall - CRBCall etc.
125   CompareAndSibcall,
126 
127   // Trap
128   CompareAndTrap
129 };
130 } // end namespace SystemZII
131 
132 class SystemZSubtarget;
133 class SystemZInstrInfo : public SystemZGenInstrInfo {
134   const SystemZRegisterInfo RI;
135   SystemZSubtarget &STI;
136 
137   void splitMove(MachineBasicBlock::iterator MI, unsigned NewOpcode) const;
138   void splitAdjDynAlloc(MachineBasicBlock::iterator MI) const;
139   void expandRIPseudo(MachineInstr &MI, unsigned LowOpcode, unsigned HighOpcode,
140                       bool ConvertHigh) const;
141   void expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
142                        unsigned LowOpcodeK, unsigned HighOpcode) const;
143   void expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
144                        unsigned HighOpcode) const;
145   void expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
146                         unsigned Size) const;
147   void expandLoadStackGuard(MachineInstr *MI) const;
148   void emitGRX32Move(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
149                      const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
150                      unsigned LowLowOpcode, unsigned Size, bool KillSrc) const;
151   virtual void anchor();
152 
153 public:
154   explicit SystemZInstrInfo(SystemZSubtarget &STI);
155 
156   // Override TargetInstrInfo.
157   unsigned isLoadFromStackSlot(const MachineInstr &MI,
158                                int &FrameIndex) const override;
159   unsigned isStoreToStackSlot(const MachineInstr &MI,
160                               int &FrameIndex) const override;
161   bool isStackSlotCopy(const MachineInstr &MI, int &DestFrameIndex,
162                        int &SrcFrameIndex) const override;
163   bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
164                      MachineBasicBlock *&FBB,
165                      SmallVectorImpl<MachineOperand> &Cond,
166                      bool AllowModify) const override;
167   unsigned RemoveBranch(MachineBasicBlock &MBB) const override;
168   unsigned InsertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
169                         MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
170                         const DebugLoc &DL) const override;
171   bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
172                       unsigned &SrcReg2, int &Mask, int &Value) const override;
173   bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
174                             unsigned SrcReg2, int Mask, int Value,
175                             const MachineRegisterInfo *MRI) const override;
176   bool isPredicable(MachineInstr &MI) const override;
177   bool isProfitableToIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
178                            unsigned ExtraPredCycles,
179                            BranchProbability Probability) const override;
180   bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
181                            unsigned NumCyclesT, unsigned ExtraPredCyclesT,
182                            MachineBasicBlock &FMBB,
183                            unsigned NumCyclesF, unsigned ExtraPredCyclesF,
184                            BranchProbability Probability) const override;
185   bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
186                             BranchProbability Probability) const override;
187   bool PredicateInstruction(MachineInstr &MI,
188                             ArrayRef<MachineOperand> Pred) const override;
189   void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
190                    const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
191                    bool KillSrc) const override;
192   void storeRegToStackSlot(MachineBasicBlock &MBB,
193                            MachineBasicBlock::iterator MBBI,
194                            unsigned SrcReg, bool isKill, int FrameIndex,
195                            const TargetRegisterClass *RC,
196                            const TargetRegisterInfo *TRI) const override;
197   void loadRegFromStackSlot(MachineBasicBlock &MBB,
198                             MachineBasicBlock::iterator MBBI,
199                             unsigned DestReg, int FrameIdx,
200                             const TargetRegisterClass *RC,
201                             const TargetRegisterInfo *TRI) const override;
202   MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
203                                       MachineInstr &MI,
204                                       LiveVariables *LV) const override;
205   MachineInstr *
206   foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
207                         ArrayRef<unsigned> Ops,
208                         MachineBasicBlock::iterator InsertPt, int FrameIndex,
209                         LiveIntervals *LIS = nullptr) const override;
210   MachineInstr *foldMemoryOperandImpl(
211       MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
212       MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
213       LiveIntervals *LIS = nullptr) const override;
214   bool expandPostRAPseudo(MachineInstr &MBBI) const override;
215   bool ReverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
216     override;
217 
218   // Return the SystemZRegisterInfo, which this class owns.
getRegisterInfo()219   const SystemZRegisterInfo &getRegisterInfo() const { return RI; }
220 
221   // Return the size in bytes of MI.
222   uint64_t getInstSizeInBytes(const MachineInstr &MI) const;
223 
224   // Return true if MI is a conditional or unconditional branch.
225   // When returning true, set Cond to the mask of condition-code
226   // values on which the instruction will branch, and set Target
227   // to the operand that contains the branch target.  This target
228   // can be a register or a basic block.
229   SystemZII::Branch getBranchInfo(const MachineInstr &MI) const;
230 
231   // Get the load and store opcodes for a given register class.
232   void getLoadStoreOpcodes(const TargetRegisterClass *RC,
233                            unsigned &LoadOpcode, unsigned &StoreOpcode) const;
234 
235   // Opcode is the opcode of an instruction that has an address operand,
236   // and the caller wants to perform that instruction's operation on an
237   // address that has displacement Offset.  Return the opcode of a suitable
238   // instruction (which might be Opcode itself) or 0 if no such instruction
239   // exists.
240   unsigned getOpcodeForOffset(unsigned Opcode, int64_t Offset) const;
241 
242   // If Opcode is a load instruction that has a LOAD AND TEST form,
243   // return the opcode for the testing form, otherwise return 0.
244   unsigned getLoadAndTest(unsigned Opcode) const;
245 
246   // Return true if ROTATE AND ... SELECTED BITS can be used to select bits
247   // Mask of the R2 operand, given that only the low BitSize bits of Mask are
248   // significant.  Set Start and End to the I3 and I4 operands if so.
249   bool isRxSBGMask(uint64_t Mask, unsigned BitSize,
250                    unsigned &Start, unsigned &End) const;
251 
252   // If Opcode is a COMPARE opcode for which an associated fused COMPARE AND *
253   // operation exists, return the opcode for the latter, otherwise return 0.
254   // MI, if nonnull, is the compare instruction.
255   unsigned getFusedCompare(unsigned Opcode,
256                            SystemZII::FusedCompareType Type,
257                            const MachineInstr *MI = nullptr) const;
258 
259   // Emit code before MBBI in MI to move immediate value Value into
260   // physical register Reg.
261   void loadImmediate(MachineBasicBlock &MBB,
262                      MachineBasicBlock::iterator MBBI,
263                      unsigned Reg, uint64_t Value) const;
264 };
265 } // end namespace llvm
266 
267 #endif
268