SystemZInstrInfo.h revision 327952 
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/ADT/ArrayRef.h"
20#include "llvm/CodeGen/MachineBasicBlock.h"
21#include "llvm/CodeGen/MachineFunction.h"
22#include "llvm/CodeGen/MachineInstrBuilder.h"
23#include "llvm/CodeGen/TargetInstrInfo.h"
24#include <cstdint>
25
26#define GET_INSTRINFO_HEADER
27#include "SystemZGenInstrInfo.inc"
28
29namespace llvm {
30
31class SystemZSubtarget;
32
33namespace SystemZII {
34
35enum {
36  // See comments in SystemZInstrFormats.td.
37  SimpleBDXLoad          = (1 << 0),
38  SimpleBDXStore         = (1 << 1),
39  Has20BitOffset         = (1 << 2),
40  HasIndex               = (1 << 3),
41  Is128Bit               = (1 << 4),
42  AccessSizeMask         = (31 << 5),
43  AccessSizeShift        = 5,
44  CCValuesMask           = (15 << 10),
45  CCValuesShift          = 10,
46  CompareZeroCCMaskMask  = (15 << 14),
47  CompareZeroCCMaskShift = 14,
48  CCMaskFirst            = (1 << 18),
49  CCMaskLast             = (1 << 19),
50  IsLogical              = (1 << 20)
51};
52
53static inline unsigned getAccessSize(unsigned int Flags) {
54  return (Flags & AccessSizeMask) >> AccessSizeShift;
55}
56
57static inline unsigned getCCValues(unsigned int Flags) {
58  return (Flags & CCValuesMask) >> CCValuesShift;
59}
60
61static inline unsigned getCompareZeroCCMask(unsigned int Flags) {
62  return (Flags & CompareZeroCCMaskMask) >> CompareZeroCCMaskShift;
63}
64
65// SystemZ MachineOperand target flags.
66enum {
67  // Masks out the bits for the access model.
68  MO_SYMBOL_MODIFIER = (3 << 0),
69
70  // @GOT (aka @GOTENT)
71  MO_GOT = (1 << 0),
72
73  // @INDNTPOFF
74  MO_INDNTPOFF = (2 << 0)
75};
76
77// Classifies a branch.
78enum BranchType {
79  // An instruction that branches on the current value of CC.
80  BranchNormal,
81
82  // An instruction that peforms a 32-bit signed comparison and branches
83  // on the result.
84  BranchC,
85
86  // An instruction that peforms a 32-bit unsigned comparison and branches
87  // on the result.
88  BranchCL,
89
90  // An instruction that peforms a 64-bit signed comparison and branches
91  // on the result.
92  BranchCG,
93
94  // An instruction that peforms a 64-bit unsigned comparison and branches
95  // on the result.
96  BranchCLG,
97
98  // An instruction that decrements a 32-bit register and branches if
99  // the result is nonzero.
100  BranchCT,
101
102  // An instruction that decrements a 64-bit register and branches if
103  // the result is nonzero.
104  BranchCTG
105};
106
107// Information about a branch instruction.
108struct Branch {
109  // The type of the branch.
110  BranchType Type;
111
112  // CCMASK_<N> is set if CC might be equal to N.
113  unsigned CCValid;
114
115  // CCMASK_<N> is set if the branch should be taken when CC == N.
116  unsigned CCMask;
117
118  // The target of the branch.
119  const MachineOperand *Target;
120
121  Branch(BranchType type, unsigned ccValid, unsigned ccMask,
122         const MachineOperand *target)
123    : Type(type), CCValid(ccValid), CCMask(ccMask), Target(target) {}
124};
125
126// Kinds of fused compares in compare-and-* instructions.  Together with type
127// of the converted compare, this identifies the compare-and-*
128// instruction.
129enum FusedCompareType {
130  // Relative branch - CRJ etc.
131  CompareAndBranch,
132
133  // Indirect branch, used for return - CRBReturn etc.
134  CompareAndReturn,
135
136  // Indirect branch, used for sibcall - CRBCall etc.
137  CompareAndSibcall,
138
139  // Trap
140  CompareAndTrap
141};
142
143} // end namespace SystemZII
144
145class SystemZInstrInfo : public SystemZGenInstrInfo {
146  const SystemZRegisterInfo RI;
147  SystemZSubtarget &STI;
148
149  void splitMove(MachineBasicBlock::iterator MI, unsigned NewOpcode) const;
150  void splitAdjDynAlloc(MachineBasicBlock::iterator MI) const;
151  void expandRIPseudo(MachineInstr &MI, unsigned LowOpcode, unsigned HighOpcode,
152                      bool ConvertHigh) const;
153  void expandRIEPseudo(MachineInstr &MI, unsigned LowOpcode,
154                       unsigned LowOpcodeK, unsigned HighOpcode) const;
155  void expandRXYPseudo(MachineInstr &MI, unsigned LowOpcode,
156                       unsigned HighOpcode) const;
157  void expandLOCPseudo(MachineInstr &MI, unsigned LowOpcode,
158                       unsigned HighOpcode) const;
159  void expandLOCRPseudo(MachineInstr &MI, unsigned LowOpcode,
160                        unsigned HighOpcode) const;
161  void expandZExtPseudo(MachineInstr &MI, unsigned LowOpcode,
162                        unsigned Size) const;
163  void expandLoadStackGuard(MachineInstr *MI) const;
164
165  MachineInstrBuilder
166  emitGRX32Move(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
167                const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
168                unsigned LowLowOpcode, unsigned Size, bool KillSrc,
169                bool UndefSrc) const;
170
171  virtual void anchor();
172
173protected:
174  /// Commutes the operands in the given instruction by changing the operands
175  /// order and/or changing the instruction's opcode and/or the immediate value
176  /// operand.
177  ///
178  /// The arguments 'CommuteOpIdx1' and 'CommuteOpIdx2' specify the operands
179  /// to be commuted.
180  ///
181  /// Do not call this method for a non-commutable instruction or
182  /// non-commutable operands.
183  /// Even though the instruction is commutable, the method may still
184  /// fail to commute the operands, null pointer is returned in such cases.
185  MachineInstr *commuteInstructionImpl(MachineInstr &MI, bool NewMI,
186                                       unsigned CommuteOpIdx1,
187                                       unsigned CommuteOpIdx2) const override;
188
189public:
190  explicit SystemZInstrInfo(SystemZSubtarget &STI);
191
192  // Override TargetInstrInfo.
193  unsigned isLoadFromStackSlot(const MachineInstr &MI,
194                               int &FrameIndex) const override;
195  unsigned isStoreToStackSlot(const MachineInstr &MI,
196                              int &FrameIndex) const override;
197  bool isStackSlotCopy(const MachineInstr &MI, int &DestFrameIndex,
198                       int &SrcFrameIndex) const override;
199  bool analyzeBranch(MachineBasicBlock &MBB, MachineBasicBlock *&TBB,
200                     MachineBasicBlock *&FBB,
201                     SmallVectorImpl<MachineOperand> &Cond,
202                     bool AllowModify) const override;
203  unsigned removeBranch(MachineBasicBlock &MBB,
204                        int *BytesRemoved = nullptr) const override;
205  unsigned insertBranch(MachineBasicBlock &MBB, MachineBasicBlock *TBB,
206                        MachineBasicBlock *FBB, ArrayRef<MachineOperand> Cond,
207                        const DebugLoc &DL,
208                        int *BytesAdded = nullptr) const override;
209  bool analyzeCompare(const MachineInstr &MI, unsigned &SrcReg,
210                      unsigned &SrcReg2, int &Mask, int &Value) const override;
211  bool optimizeCompareInstr(MachineInstr &CmpInstr, unsigned SrcReg,
212                            unsigned SrcReg2, int Mask, int Value,
213                            const MachineRegisterInfo *MRI) const override;
214  bool canInsertSelect(const MachineBasicBlock&, ArrayRef<MachineOperand> Cond,
215                       unsigned, unsigned, int&, int&, int&) const override;
216  void insertSelect(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI,
217                    const DebugLoc &DL, unsigned DstReg,
218                    ArrayRef<MachineOperand> Cond, unsigned TrueReg,
219                    unsigned FalseReg) const override;
220  bool FoldImmediate(MachineInstr &UseMI, MachineInstr &DefMI, unsigned Reg,
221                     MachineRegisterInfo *MRI) const override;
222  bool isPredicable(const MachineInstr &MI) const override;
223  bool isProfitableToIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
224                           unsigned ExtraPredCycles,
225                           BranchProbability Probability) const override;
226  bool isProfitableToIfCvt(MachineBasicBlock &TMBB,
227                           unsigned NumCyclesT, unsigned ExtraPredCyclesT,
228                           MachineBasicBlock &FMBB,
229                           unsigned NumCyclesF, unsigned ExtraPredCyclesF,
230                           BranchProbability Probability) const override;
231  bool isProfitableToDupForIfCvt(MachineBasicBlock &MBB, unsigned NumCycles,
232                            BranchProbability Probability) const override;
233  bool PredicateInstruction(MachineInstr &MI,
234                            ArrayRef<MachineOperand> Pred) const override;
235  void copyPhysReg(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
236                   const DebugLoc &DL, unsigned DestReg, unsigned SrcReg,
237                   bool KillSrc) const override;
238  void storeRegToStackSlot(MachineBasicBlock &MBB,
239                           MachineBasicBlock::iterator MBBI,
240                           unsigned SrcReg, bool isKill, int FrameIndex,
241                           const TargetRegisterClass *RC,
242                           const TargetRegisterInfo *TRI) const override;
243  void loadRegFromStackSlot(MachineBasicBlock &MBB,
244                            MachineBasicBlock::iterator MBBI,
245                            unsigned DestReg, int FrameIdx,
246                            const TargetRegisterClass *RC,
247                            const TargetRegisterInfo *TRI) const override;
248  MachineInstr *convertToThreeAddress(MachineFunction::iterator &MFI,
249                                      MachineInstr &MI,
250                                      LiveVariables *LV) const override;
251  MachineInstr *
252  foldMemoryOperandImpl(MachineFunction &MF, MachineInstr &MI,
253                        ArrayRef<unsigned> Ops,
254                        MachineBasicBlock::iterator InsertPt, int FrameIndex,
255                        LiveIntervals *LIS = nullptr) const override;
256  MachineInstr *foldMemoryOperandImpl(
257      MachineFunction &MF, MachineInstr &MI, ArrayRef<unsigned> Ops,
258      MachineBasicBlock::iterator InsertPt, MachineInstr &LoadMI,
259      LiveIntervals *LIS = nullptr) const override;
260  bool expandPostRAPseudo(MachineInstr &MBBI) const override;
261  bool reverseBranchCondition(SmallVectorImpl<MachineOperand> &Cond) const
262    override;
263
264  // Return the SystemZRegisterInfo, which this class owns.
265  const SystemZRegisterInfo &getRegisterInfo() const { return RI; }
266
267  // Return the size in bytes of MI.
268  unsigned getInstSizeInBytes(const MachineInstr &MI) const override;
269
270  // Return true if MI is a conditional or unconditional branch.
271  // When returning true, set Cond to the mask of condition-code
272  // values on which the instruction will branch, and set Target
273  // to the operand that contains the branch target.  This target
274  // can be a register or a basic block.
275  SystemZII::Branch getBranchInfo(const MachineInstr &MI) const;
276
277  // Get the load and store opcodes for a given register class.
278  void getLoadStoreOpcodes(const TargetRegisterClass *RC,
279                           unsigned &LoadOpcode, unsigned &StoreOpcode) const;
280
281  // Opcode is the opcode of an instruction that has an address operand,
282  // and the caller wants to perform that instruction's operation on an
283  // address that has displacement Offset.  Return the opcode of a suitable
284  // instruction (which might be Opcode itself) or 0 if no such instruction
285  // exists.
286  unsigned getOpcodeForOffset(unsigned Opcode, int64_t Offset) const;
287
288  // If Opcode is a load instruction that has a LOAD AND TEST form,
289  // return the opcode for the testing form, otherwise return 0.
290  unsigned getLoadAndTest(unsigned Opcode) const;
291
292  // Return true if ROTATE AND ... SELECTED BITS can be used to select bits
293  // Mask of the R2 operand, given that only the low BitSize bits of Mask are
294  // significant.  Set Start and End to the I3 and I4 operands if so.
295  bool isRxSBGMask(uint64_t Mask, unsigned BitSize,
296                   unsigned &Start, unsigned &End) const;
297
298  // If Opcode is a COMPARE opcode for which an associated fused COMPARE AND *
299  // operation exists, return the opcode for the latter, otherwise return 0.
300  // MI, if nonnull, is the compare instruction.
301  unsigned getFusedCompare(unsigned Opcode,
302                           SystemZII::FusedCompareType Type,
303                           const MachineInstr *MI = nullptr) const;
304
305  // If Opcode is a LOAD opcode for with an associated LOAD AND TRAP
306  // operation exists, returh the opcode for the latter, otherwise return 0.
307  unsigned getLoadAndTrap(unsigned Opcode) const;
308
309  // Emit code before MBBI in MI to move immediate value Value into
310  // physical register Reg.
311  void loadImmediate(MachineBasicBlock &MBB,
312                     MachineBasicBlock::iterator MBBI,
313                     unsigned Reg, uint64_t Value) const;
314
315  // Sometimes, it is possible for the target to tell, even without
316  // aliasing information, that two MIs access different memory
317  // addresses. This function returns true if two MIs access different
318  // memory addresses and false otherwise.
319  bool
320  areMemAccessesTriviallyDisjoint(MachineInstr &MIa, MachineInstr &MIb,
321                                  AliasAnalysis *AA = nullptr) const override;
322};
323
324} // end namespace llvm
325
326#endif // LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZINSTRINFO_H
327