1 //===- X86InstructionSelector.cpp -----------------------------------------===//
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 /// \file
10 /// This file implements the targeting of the InstructionSelector class for
11 /// X86.
12 /// \todo This should be generated by TableGen.
13 //===----------------------------------------------------------------------===//
14 
15 #include "MCTargetDesc/X86BaseInfo.h"
16 #include "X86InstrBuilder.h"
17 #include "X86InstrInfo.h"
18 #include "X86RegisterBankInfo.h"
19 #include "X86RegisterInfo.h"
20 #include "X86Subtarget.h"
21 #include "X86TargetMachine.h"
22 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
23 #include "llvm/CodeGen/GlobalISel/InstructionSelectorImpl.h"
24 #include "llvm/CodeGen/GlobalISel/RegisterBank.h"
25 #include "llvm/CodeGen/GlobalISel/Utils.h"
26 #include "llvm/CodeGen/MachineBasicBlock.h"
27 #include "llvm/CodeGen/MachineConstantPool.h"
28 #include "llvm/CodeGen/MachineFunction.h"
29 #include "llvm/CodeGen/MachineInstr.h"
30 #include "llvm/CodeGen/MachineInstrBuilder.h"
31 #include "llvm/CodeGen/MachineMemOperand.h"
32 #include "llvm/CodeGen/MachineOperand.h"
33 #include "llvm/CodeGen/MachineRegisterInfo.h"
34 #include "llvm/CodeGen/TargetOpcodes.h"
35 #include "llvm/CodeGen/TargetRegisterInfo.h"
36 #include "llvm/IR/DataLayout.h"
37 #include "llvm/IR/InstrTypes.h"
38 #include "llvm/Support/AtomicOrdering.h"
39 #include "llvm/Support/CodeGen.h"
40 #include "llvm/Support/Debug.h"
41 #include "llvm/Support/ErrorHandling.h"
42 #include "llvm/Support/LowLevelTypeImpl.h"
43 #include "llvm/Support/MathExtras.h"
44 #include "llvm/Support/raw_ostream.h"
45 #include <cassert>
46 #include <cstdint>
47 #include <tuple>
48 
49 #define DEBUG_TYPE "X86-isel"
50 
51 using namespace llvm;
52 
53 namespace {
54 
55 #define GET_GLOBALISEL_PREDICATE_BITSET
56 #include "X86GenGlobalISel.inc"
57 #undef GET_GLOBALISEL_PREDICATE_BITSET
58 
59 class X86InstructionSelector : public InstructionSelector {
60 public:
61   X86InstructionSelector(const X86TargetMachine &TM, const X86Subtarget &STI,
62                          const X86RegisterBankInfo &RBI);
63 
64   bool select(MachineInstr &I, CodeGenCoverage &CoverageInfo) const override;
getName()65   static const char *getName() { return DEBUG_TYPE; }
66 
67 private:
68   /// tblgen-erated 'select' implementation, used as the initial selector for
69   /// the patterns that don't require complex C++.
70   bool selectImpl(MachineInstr &I, CodeGenCoverage &CoverageInfo) const;
71 
72   // TODO: remove after supported by Tablegen-erated instruction selection.
73   unsigned getLoadStoreOp(const LLT &Ty, const RegisterBank &RB, unsigned Opc,
74                           uint64_t Alignment) const;
75 
76   bool selectLoadStoreOp(MachineInstr &I, MachineRegisterInfo &MRI,
77                          MachineFunction &MF) const;
78   bool selectFrameIndexOrGep(MachineInstr &I, MachineRegisterInfo &MRI,
79                              MachineFunction &MF) const;
80   bool selectGlobalValue(MachineInstr &I, MachineRegisterInfo &MRI,
81                          MachineFunction &MF) const;
82   bool selectConstant(MachineInstr &I, MachineRegisterInfo &MRI,
83                       MachineFunction &MF) const;
84   bool selectTruncOrPtrToInt(MachineInstr &I, MachineRegisterInfo &MRI,
85                              MachineFunction &MF) const;
86   bool selectZext(MachineInstr &I, MachineRegisterInfo &MRI,
87                   MachineFunction &MF) const;
88   bool selectAnyext(MachineInstr &I, MachineRegisterInfo &MRI,
89                     MachineFunction &MF) const;
90   bool selectCmp(MachineInstr &I, MachineRegisterInfo &MRI,
91                  MachineFunction &MF) const;
92   bool selectUadde(MachineInstr &I, MachineRegisterInfo &MRI,
93                    MachineFunction &MF) const;
94   bool selectCopy(MachineInstr &I, MachineRegisterInfo &MRI) const;
95   bool selectUnmergeValues(MachineInstr &I, MachineRegisterInfo &MRI,
96                            MachineFunction &MF,
97                            CodeGenCoverage &CoverageInfo) const;
98   bool selectMergeValues(MachineInstr &I, MachineRegisterInfo &MRI,
99                          MachineFunction &MF,
100                          CodeGenCoverage &CoverageInfo) const;
101   bool selectInsert(MachineInstr &I, MachineRegisterInfo &MRI,
102                     MachineFunction &MF) const;
103   bool selectExtract(MachineInstr &I, MachineRegisterInfo &MRI,
104                      MachineFunction &MF) const;
105   bool selectCondBranch(MachineInstr &I, MachineRegisterInfo &MRI,
106                         MachineFunction &MF) const;
107   bool selectTurnIntoCOPY(MachineInstr &I, MachineRegisterInfo &MRI,
108                           const unsigned DstReg,
109                           const TargetRegisterClass *DstRC,
110                           const unsigned SrcReg,
111                           const TargetRegisterClass *SrcRC) const;
112   bool materializeFP(MachineInstr &I, MachineRegisterInfo &MRI,
113                      MachineFunction &MF) const;
114   bool selectImplicitDefOrPHI(MachineInstr &I, MachineRegisterInfo &MRI) const;
115   bool selectShift(MachineInstr &I, MachineRegisterInfo &MRI,
116                    MachineFunction &MF) const;
117   bool selectSDiv(MachineInstr &I, MachineRegisterInfo &MRI,
118                    MachineFunction &MF) const;
119 
120   // emit insert subreg instruction and insert it before MachineInstr &I
121   bool emitInsertSubreg(unsigned DstReg, unsigned SrcReg, MachineInstr &I,
122                         MachineRegisterInfo &MRI, MachineFunction &MF) const;
123   // emit extract subreg instruction and insert it before MachineInstr &I
124   bool emitExtractSubreg(unsigned DstReg, unsigned SrcReg, MachineInstr &I,
125                          MachineRegisterInfo &MRI, MachineFunction &MF) const;
126 
127   const TargetRegisterClass *getRegClass(LLT Ty, const RegisterBank &RB) const;
128   const TargetRegisterClass *getRegClass(LLT Ty, unsigned Reg,
129                                          MachineRegisterInfo &MRI) const;
130 
131   const X86TargetMachine &TM;
132   const X86Subtarget &STI;
133   const X86InstrInfo &TII;
134   const X86RegisterInfo &TRI;
135   const X86RegisterBankInfo &RBI;
136 
137 #define GET_GLOBALISEL_PREDICATES_DECL
138 #include "X86GenGlobalISel.inc"
139 #undef GET_GLOBALISEL_PREDICATES_DECL
140 
141 #define GET_GLOBALISEL_TEMPORARIES_DECL
142 #include "X86GenGlobalISel.inc"
143 #undef GET_GLOBALISEL_TEMPORARIES_DECL
144 };
145 
146 } // end anonymous namespace
147 
148 #define GET_GLOBALISEL_IMPL
149 #include "X86GenGlobalISel.inc"
150 #undef GET_GLOBALISEL_IMPL
151 
X86InstructionSelector(const X86TargetMachine & TM,const X86Subtarget & STI,const X86RegisterBankInfo & RBI)152 X86InstructionSelector::X86InstructionSelector(const X86TargetMachine &TM,
153                                                const X86Subtarget &STI,
154                                                const X86RegisterBankInfo &RBI)
155     : InstructionSelector(), TM(TM), STI(STI), TII(*STI.getInstrInfo()),
156       TRI(*STI.getRegisterInfo()), RBI(RBI),
157 #define GET_GLOBALISEL_PREDICATES_INIT
158 #include "X86GenGlobalISel.inc"
159 #undef GET_GLOBALISEL_PREDICATES_INIT
160 #define GET_GLOBALISEL_TEMPORARIES_INIT
161 #include "X86GenGlobalISel.inc"
162 #undef GET_GLOBALISEL_TEMPORARIES_INIT
163 {
164 }
165 
166 // FIXME: This should be target-independent, inferred from the types declared
167 // for each class in the bank.
168 const TargetRegisterClass *
getRegClass(LLT Ty,const RegisterBank & RB) const169 X86InstructionSelector::getRegClass(LLT Ty, const RegisterBank &RB) const {
170   if (RB.getID() == X86::GPRRegBankID) {
171     if (Ty.getSizeInBits() <= 8)
172       return &X86::GR8RegClass;
173     if (Ty.getSizeInBits() == 16)
174       return &X86::GR16RegClass;
175     if (Ty.getSizeInBits() == 32)
176       return &X86::GR32RegClass;
177     if (Ty.getSizeInBits() == 64)
178       return &X86::GR64RegClass;
179   }
180   if (RB.getID() == X86::VECRRegBankID) {
181     if (Ty.getSizeInBits() == 32)
182       return STI.hasAVX512() ? &X86::FR32XRegClass : &X86::FR32RegClass;
183     if (Ty.getSizeInBits() == 64)
184       return STI.hasAVX512() ? &X86::FR64XRegClass : &X86::FR64RegClass;
185     if (Ty.getSizeInBits() == 128)
186       return STI.hasAVX512() ? &X86::VR128XRegClass : &X86::VR128RegClass;
187     if (Ty.getSizeInBits() == 256)
188       return STI.hasAVX512() ? &X86::VR256XRegClass : &X86::VR256RegClass;
189     if (Ty.getSizeInBits() == 512)
190       return &X86::VR512RegClass;
191   }
192 
193   llvm_unreachable("Unknown RegBank!");
194 }
195 
196 const TargetRegisterClass *
getRegClass(LLT Ty,unsigned Reg,MachineRegisterInfo & MRI) const197 X86InstructionSelector::getRegClass(LLT Ty, unsigned Reg,
198                                     MachineRegisterInfo &MRI) const {
199   const RegisterBank &RegBank = *RBI.getRegBank(Reg, MRI, TRI);
200   return getRegClass(Ty, RegBank);
201 }
202 
getSubRegIndex(const TargetRegisterClass * RC)203 static unsigned getSubRegIndex(const TargetRegisterClass *RC) {
204   unsigned SubIdx = X86::NoSubRegister;
205   if (RC == &X86::GR32RegClass) {
206     SubIdx = X86::sub_32bit;
207   } else if (RC == &X86::GR16RegClass) {
208     SubIdx = X86::sub_16bit;
209   } else if (RC == &X86::GR8RegClass) {
210     SubIdx = X86::sub_8bit;
211   }
212 
213   return SubIdx;
214 }
215 
getRegClassFromGRPhysReg(unsigned Reg)216 static const TargetRegisterClass *getRegClassFromGRPhysReg(unsigned Reg) {
217   assert(TargetRegisterInfo::isPhysicalRegister(Reg));
218   if (X86::GR64RegClass.contains(Reg))
219     return &X86::GR64RegClass;
220   if (X86::GR32RegClass.contains(Reg))
221     return &X86::GR32RegClass;
222   if (X86::GR16RegClass.contains(Reg))
223     return &X86::GR16RegClass;
224   if (X86::GR8RegClass.contains(Reg))
225     return &X86::GR8RegClass;
226 
227   llvm_unreachable("Unknown RegClass for PhysReg!");
228 }
229 
230 // Set X86 Opcode and constrain DestReg.
selectCopy(MachineInstr & I,MachineRegisterInfo & MRI) const231 bool X86InstructionSelector::selectCopy(MachineInstr &I,
232                                         MachineRegisterInfo &MRI) const {
233   unsigned DstReg = I.getOperand(0).getReg();
234   const unsigned DstSize = RBI.getSizeInBits(DstReg, MRI, TRI);
235   const RegisterBank &DstRegBank = *RBI.getRegBank(DstReg, MRI, TRI);
236 
237   unsigned SrcReg = I.getOperand(1).getReg();
238   const unsigned SrcSize = RBI.getSizeInBits(SrcReg, MRI, TRI);
239   const RegisterBank &SrcRegBank = *RBI.getRegBank(SrcReg, MRI, TRI);
240 
241   if (TargetRegisterInfo::isPhysicalRegister(DstReg)) {
242     assert(I.isCopy() && "Generic operators do not allow physical registers");
243 
244     if (DstSize > SrcSize && SrcRegBank.getID() == X86::GPRRegBankID &&
245         DstRegBank.getID() == X86::GPRRegBankID) {
246 
247       const TargetRegisterClass *SrcRC =
248           getRegClass(MRI.getType(SrcReg), SrcRegBank);
249       const TargetRegisterClass *DstRC = getRegClassFromGRPhysReg(DstReg);
250 
251       if (SrcRC != DstRC) {
252         // This case can be generated by ABI lowering, performe anyext
253         unsigned ExtSrc = MRI.createVirtualRegister(DstRC);
254         BuildMI(*I.getParent(), I, I.getDebugLoc(),
255                 TII.get(TargetOpcode::SUBREG_TO_REG))
256             .addDef(ExtSrc)
257             .addImm(0)
258             .addReg(SrcReg)
259             .addImm(getSubRegIndex(SrcRC));
260 
261         I.getOperand(1).setReg(ExtSrc);
262       }
263     }
264 
265     return true;
266   }
267 
268   assert((!TargetRegisterInfo::isPhysicalRegister(SrcReg) || I.isCopy()) &&
269          "No phys reg on generic operators");
270   assert((DstSize == SrcSize ||
271           // Copies are a mean to setup initial types, the number of
272           // bits may not exactly match.
273           (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
274            DstSize <= RBI.getSizeInBits(SrcReg, MRI, TRI))) &&
275          "Copy with different width?!");
276 
277   const TargetRegisterClass *DstRC =
278       getRegClass(MRI.getType(DstReg), DstRegBank);
279 
280   if (SrcRegBank.getID() == X86::GPRRegBankID &&
281       DstRegBank.getID() == X86::GPRRegBankID && SrcSize > DstSize &&
282       TargetRegisterInfo::isPhysicalRegister(SrcReg)) {
283     // Change the physical register to performe truncate.
284 
285     const TargetRegisterClass *SrcRC = getRegClassFromGRPhysReg(SrcReg);
286 
287     if (DstRC != SrcRC) {
288       I.getOperand(1).setSubReg(getSubRegIndex(DstRC));
289       I.getOperand(1).substPhysReg(SrcReg, TRI);
290     }
291   }
292 
293   // No need to constrain SrcReg. It will get constrained when
294   // we hit another of its use or its defs.
295   // Copies do not have constraints.
296   const TargetRegisterClass *OldRC = MRI.getRegClassOrNull(DstReg);
297   if (!OldRC || !DstRC->hasSubClassEq(OldRC)) {
298     if (!RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
299       LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
300                         << " operand\n");
301       return false;
302     }
303   }
304   I.setDesc(TII.get(X86::COPY));
305   return true;
306 }
307 
select(MachineInstr & I,CodeGenCoverage & CoverageInfo) const308 bool X86InstructionSelector::select(MachineInstr &I,
309                                     CodeGenCoverage &CoverageInfo) const {
310   assert(I.getParent() && "Instruction should be in a basic block!");
311   assert(I.getParent()->getParent() && "Instruction should be in a function!");
312 
313   MachineBasicBlock &MBB = *I.getParent();
314   MachineFunction &MF = *MBB.getParent();
315   MachineRegisterInfo &MRI = MF.getRegInfo();
316 
317   unsigned Opcode = I.getOpcode();
318   if (!isPreISelGenericOpcode(Opcode)) {
319     // Certain non-generic instructions also need some special handling.
320 
321     if (Opcode == TargetOpcode::LOAD_STACK_GUARD)
322       return false;
323 
324     if (I.isCopy())
325       return selectCopy(I, MRI);
326 
327     return true;
328   }
329 
330   assert(I.getNumOperands() == I.getNumExplicitOperands() &&
331          "Generic instruction has unexpected implicit operands\n");
332 
333   if (selectImpl(I, CoverageInfo))
334     return true;
335 
336   LLVM_DEBUG(dbgs() << " C++ instruction selection: "; I.print(dbgs()));
337 
338   // TODO: This should be implemented by tblgen.
339   switch (I.getOpcode()) {
340   default:
341     return false;
342   case TargetOpcode::G_STORE:
343   case TargetOpcode::G_LOAD:
344     return selectLoadStoreOp(I, MRI, MF);
345   case TargetOpcode::G_GEP:
346   case TargetOpcode::G_FRAME_INDEX:
347     return selectFrameIndexOrGep(I, MRI, MF);
348   case TargetOpcode::G_GLOBAL_VALUE:
349     return selectGlobalValue(I, MRI, MF);
350   case TargetOpcode::G_CONSTANT:
351     return selectConstant(I, MRI, MF);
352   case TargetOpcode::G_FCONSTANT:
353     return materializeFP(I, MRI, MF);
354   case TargetOpcode::G_PTRTOINT:
355   case TargetOpcode::G_TRUNC:
356     return selectTruncOrPtrToInt(I, MRI, MF);
357   case TargetOpcode::G_INTTOPTR:
358     return selectCopy(I, MRI);
359   case TargetOpcode::G_ZEXT:
360     return selectZext(I, MRI, MF);
361   case TargetOpcode::G_ANYEXT:
362     return selectAnyext(I, MRI, MF);
363   case TargetOpcode::G_ICMP:
364     return selectCmp(I, MRI, MF);
365   case TargetOpcode::G_UADDE:
366     return selectUadde(I, MRI, MF);
367   case TargetOpcode::G_UNMERGE_VALUES:
368     return selectUnmergeValues(I, MRI, MF, CoverageInfo);
369   case TargetOpcode::G_MERGE_VALUES:
370     return selectMergeValues(I, MRI, MF, CoverageInfo);
371   case TargetOpcode::G_EXTRACT:
372     return selectExtract(I, MRI, MF);
373   case TargetOpcode::G_INSERT:
374     return selectInsert(I, MRI, MF);
375   case TargetOpcode::G_BRCOND:
376     return selectCondBranch(I, MRI, MF);
377   case TargetOpcode::G_IMPLICIT_DEF:
378   case TargetOpcode::G_PHI:
379     return selectImplicitDefOrPHI(I, MRI);
380   case TargetOpcode::G_SHL:
381   case TargetOpcode::G_ASHR:
382   case TargetOpcode::G_LSHR:
383     return selectShift(I, MRI, MF);
384   case TargetOpcode::G_SDIV:
385     return selectSDiv(I, MRI, MF);
386   }
387 
388   return false;
389 }
390 
getLoadStoreOp(const LLT & Ty,const RegisterBank & RB,unsigned Opc,uint64_t Alignment) const391 unsigned X86InstructionSelector::getLoadStoreOp(const LLT &Ty,
392                                                 const RegisterBank &RB,
393                                                 unsigned Opc,
394                                                 uint64_t Alignment) const {
395   bool Isload = (Opc == TargetOpcode::G_LOAD);
396   bool HasAVX = STI.hasAVX();
397   bool HasAVX512 = STI.hasAVX512();
398   bool HasVLX = STI.hasVLX();
399 
400   if (Ty == LLT::scalar(8)) {
401     if (X86::GPRRegBankID == RB.getID())
402       return Isload ? X86::MOV8rm : X86::MOV8mr;
403   } else if (Ty == LLT::scalar(16)) {
404     if (X86::GPRRegBankID == RB.getID())
405       return Isload ? X86::MOV16rm : X86::MOV16mr;
406   } else if (Ty == LLT::scalar(32) || Ty == LLT::pointer(0, 32)) {
407     if (X86::GPRRegBankID == RB.getID())
408       return Isload ? X86::MOV32rm : X86::MOV32mr;
409     if (X86::VECRRegBankID == RB.getID())
410       return Isload ? (HasAVX512 ? X86::VMOVSSZrm
411                                  : HasAVX ? X86::VMOVSSrm : X86::MOVSSrm)
412                     : (HasAVX512 ? X86::VMOVSSZmr
413                                  : HasAVX ? X86::VMOVSSmr : X86::MOVSSmr);
414   } else if (Ty == LLT::scalar(64) || Ty == LLT::pointer(0, 64)) {
415     if (X86::GPRRegBankID == RB.getID())
416       return Isload ? X86::MOV64rm : X86::MOV64mr;
417     if (X86::VECRRegBankID == RB.getID())
418       return Isload ? (HasAVX512 ? X86::VMOVSDZrm
419                                  : HasAVX ? X86::VMOVSDrm : X86::MOVSDrm)
420                     : (HasAVX512 ? X86::VMOVSDZmr
421                                  : HasAVX ? X86::VMOVSDmr : X86::MOVSDmr);
422   } else if (Ty.isVector() && Ty.getSizeInBits() == 128) {
423     if (Alignment >= 16)
424       return Isload ? (HasVLX ? X86::VMOVAPSZ128rm
425                               : HasAVX512
426                                     ? X86::VMOVAPSZ128rm_NOVLX
427                                     : HasAVX ? X86::VMOVAPSrm : X86::MOVAPSrm)
428                     : (HasVLX ? X86::VMOVAPSZ128mr
429                               : HasAVX512
430                                     ? X86::VMOVAPSZ128mr_NOVLX
431                                     : HasAVX ? X86::VMOVAPSmr : X86::MOVAPSmr);
432     else
433       return Isload ? (HasVLX ? X86::VMOVUPSZ128rm
434                               : HasAVX512
435                                     ? X86::VMOVUPSZ128rm_NOVLX
436                                     : HasAVX ? X86::VMOVUPSrm : X86::MOVUPSrm)
437                     : (HasVLX ? X86::VMOVUPSZ128mr
438                               : HasAVX512
439                                     ? X86::VMOVUPSZ128mr_NOVLX
440                                     : HasAVX ? X86::VMOVUPSmr : X86::MOVUPSmr);
441   } else if (Ty.isVector() && Ty.getSizeInBits() == 256) {
442     if (Alignment >= 32)
443       return Isload ? (HasVLX ? X86::VMOVAPSZ256rm
444                               : HasAVX512 ? X86::VMOVAPSZ256rm_NOVLX
445                                           : X86::VMOVAPSYrm)
446                     : (HasVLX ? X86::VMOVAPSZ256mr
447                               : HasAVX512 ? X86::VMOVAPSZ256mr_NOVLX
448                                           : X86::VMOVAPSYmr);
449     else
450       return Isload ? (HasVLX ? X86::VMOVUPSZ256rm
451                               : HasAVX512 ? X86::VMOVUPSZ256rm_NOVLX
452                                           : X86::VMOVUPSYrm)
453                     : (HasVLX ? X86::VMOVUPSZ256mr
454                               : HasAVX512 ? X86::VMOVUPSZ256mr_NOVLX
455                                           : X86::VMOVUPSYmr);
456   } else if (Ty.isVector() && Ty.getSizeInBits() == 512) {
457     if (Alignment >= 64)
458       return Isload ? X86::VMOVAPSZrm : X86::VMOVAPSZmr;
459     else
460       return Isload ? X86::VMOVUPSZrm : X86::VMOVUPSZmr;
461   }
462   return Opc;
463 }
464 
465 // Fill in an address from the given instruction.
X86SelectAddress(const MachineInstr & I,const MachineRegisterInfo & MRI,X86AddressMode & AM)466 static void X86SelectAddress(const MachineInstr &I,
467                              const MachineRegisterInfo &MRI,
468                              X86AddressMode &AM) {
469   assert(I.getOperand(0).isReg() && "unsupported opperand.");
470   assert(MRI.getType(I.getOperand(0).getReg()).isPointer() &&
471          "unsupported type.");
472 
473   if (I.getOpcode() == TargetOpcode::G_GEP) {
474     if (auto COff = getConstantVRegVal(I.getOperand(2).getReg(), MRI)) {
475       int64_t Imm = *COff;
476       if (isInt<32>(Imm)) { // Check for displacement overflow.
477         AM.Disp = static_cast<int32_t>(Imm);
478         AM.Base.Reg = I.getOperand(1).getReg();
479         return;
480       }
481     }
482   } else if (I.getOpcode() == TargetOpcode::G_FRAME_INDEX) {
483     AM.Base.FrameIndex = I.getOperand(1).getIndex();
484     AM.BaseType = X86AddressMode::FrameIndexBase;
485     return;
486   }
487 
488   // Default behavior.
489   AM.Base.Reg = I.getOperand(0).getReg();
490 }
491 
selectLoadStoreOp(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const492 bool X86InstructionSelector::selectLoadStoreOp(MachineInstr &I,
493                                                MachineRegisterInfo &MRI,
494                                                MachineFunction &MF) const {
495   unsigned Opc = I.getOpcode();
496 
497   assert((Opc == TargetOpcode::G_STORE || Opc == TargetOpcode::G_LOAD) &&
498          "unexpected instruction");
499 
500   const unsigned DefReg = I.getOperand(0).getReg();
501   LLT Ty = MRI.getType(DefReg);
502   const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
503 
504   auto &MemOp = **I.memoperands_begin();
505   if (MemOp.getOrdering() != AtomicOrdering::NotAtomic) {
506     LLVM_DEBUG(dbgs() << "Atomic load/store not supported yet\n");
507     return false;
508   }
509 
510   unsigned NewOpc = getLoadStoreOp(Ty, RB, Opc, MemOp.getAlignment());
511   if (NewOpc == Opc)
512     return false;
513 
514   X86AddressMode AM;
515   X86SelectAddress(*MRI.getVRegDef(I.getOperand(1).getReg()), MRI, AM);
516 
517   I.setDesc(TII.get(NewOpc));
518   MachineInstrBuilder MIB(MF, I);
519   if (Opc == TargetOpcode::G_LOAD) {
520     I.RemoveOperand(1);
521     addFullAddress(MIB, AM);
522   } else {
523     // G_STORE (VAL, Addr), X86Store instruction (Addr, VAL)
524     I.RemoveOperand(1);
525     I.RemoveOperand(0);
526     addFullAddress(MIB, AM).addUse(DefReg);
527   }
528   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
529 }
530 
getLeaOP(LLT Ty,const X86Subtarget & STI)531 static unsigned getLeaOP(LLT Ty, const X86Subtarget &STI) {
532   if (Ty == LLT::pointer(0, 64))
533     return X86::LEA64r;
534   else if (Ty == LLT::pointer(0, 32))
535     return STI.isTarget64BitILP32() ? X86::LEA64_32r : X86::LEA32r;
536   else
537     llvm_unreachable("Can't get LEA opcode. Unsupported type.");
538 }
539 
selectFrameIndexOrGep(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const540 bool X86InstructionSelector::selectFrameIndexOrGep(MachineInstr &I,
541                                                    MachineRegisterInfo &MRI,
542                                                    MachineFunction &MF) const {
543   unsigned Opc = I.getOpcode();
544 
545   assert((Opc == TargetOpcode::G_FRAME_INDEX || Opc == TargetOpcode::G_GEP) &&
546          "unexpected instruction");
547 
548   const unsigned DefReg = I.getOperand(0).getReg();
549   LLT Ty = MRI.getType(DefReg);
550 
551   // Use LEA to calculate frame index and GEP
552   unsigned NewOpc = getLeaOP(Ty, STI);
553   I.setDesc(TII.get(NewOpc));
554   MachineInstrBuilder MIB(MF, I);
555 
556   if (Opc == TargetOpcode::G_FRAME_INDEX) {
557     addOffset(MIB, 0);
558   } else {
559     MachineOperand &InxOp = I.getOperand(2);
560     I.addOperand(InxOp);        // set IndexReg
561     InxOp.ChangeToImmediate(1); // set Scale
562     MIB.addImm(0).addReg(0);
563   }
564 
565   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
566 }
567 
selectGlobalValue(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const568 bool X86InstructionSelector::selectGlobalValue(MachineInstr &I,
569                                                MachineRegisterInfo &MRI,
570                                                MachineFunction &MF) const {
571   assert((I.getOpcode() == TargetOpcode::G_GLOBAL_VALUE) &&
572          "unexpected instruction");
573 
574   auto GV = I.getOperand(1).getGlobal();
575   if (GV->isThreadLocal()) {
576     return false; // TODO: we don't support TLS yet.
577   }
578 
579   // Can't handle alternate code models yet.
580   if (TM.getCodeModel() != CodeModel::Small)
581     return false;
582 
583   X86AddressMode AM;
584   AM.GV = GV;
585   AM.GVOpFlags = STI.classifyGlobalReference(GV);
586 
587   // TODO: The ABI requires an extra load. not supported yet.
588   if (isGlobalStubReference(AM.GVOpFlags))
589     return false;
590 
591   // TODO: This reference is relative to the pic base. not supported yet.
592   if (isGlobalRelativeToPICBase(AM.GVOpFlags))
593     return false;
594 
595   if (STI.isPICStyleRIPRel()) {
596     // Use rip-relative addressing.
597     assert(AM.Base.Reg == 0 && AM.IndexReg == 0);
598     AM.Base.Reg = X86::RIP;
599   }
600 
601   const unsigned DefReg = I.getOperand(0).getReg();
602   LLT Ty = MRI.getType(DefReg);
603   unsigned NewOpc = getLeaOP(Ty, STI);
604 
605   I.setDesc(TII.get(NewOpc));
606   MachineInstrBuilder MIB(MF, I);
607 
608   I.RemoveOperand(1);
609   addFullAddress(MIB, AM);
610 
611   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
612 }
613 
selectConstant(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const614 bool X86InstructionSelector::selectConstant(MachineInstr &I,
615                                             MachineRegisterInfo &MRI,
616                                             MachineFunction &MF) const {
617   assert((I.getOpcode() == TargetOpcode::G_CONSTANT) &&
618          "unexpected instruction");
619 
620   const unsigned DefReg = I.getOperand(0).getReg();
621   LLT Ty = MRI.getType(DefReg);
622 
623   if (RBI.getRegBank(DefReg, MRI, TRI)->getID() != X86::GPRRegBankID)
624     return false;
625 
626   uint64_t Val = 0;
627   if (I.getOperand(1).isCImm()) {
628     Val = I.getOperand(1).getCImm()->getZExtValue();
629     I.getOperand(1).ChangeToImmediate(Val);
630   } else if (I.getOperand(1).isImm()) {
631     Val = I.getOperand(1).getImm();
632   } else
633     llvm_unreachable("Unsupported operand type.");
634 
635   unsigned NewOpc;
636   switch (Ty.getSizeInBits()) {
637   case 8:
638     NewOpc = X86::MOV8ri;
639     break;
640   case 16:
641     NewOpc = X86::MOV16ri;
642     break;
643   case 32:
644     NewOpc = X86::MOV32ri;
645     break;
646   case 64:
647     // TODO: in case isUInt<32>(Val), X86::MOV32ri can be used
648     if (isInt<32>(Val))
649       NewOpc = X86::MOV64ri32;
650     else
651       NewOpc = X86::MOV64ri;
652     break;
653   default:
654     llvm_unreachable("Can't select G_CONSTANT, unsupported type.");
655   }
656 
657   I.setDesc(TII.get(NewOpc));
658   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
659 }
660 
661 // Helper function for selectTruncOrPtrToInt and selectAnyext.
662 // Returns true if DstRC lives on a floating register class and
663 // SrcRC lives on a 128-bit vector class.
canTurnIntoCOPY(const TargetRegisterClass * DstRC,const TargetRegisterClass * SrcRC)664 static bool canTurnIntoCOPY(const TargetRegisterClass *DstRC,
665                             const TargetRegisterClass *SrcRC) {
666   return (DstRC == &X86::FR32RegClass || DstRC == &X86::FR32XRegClass ||
667           DstRC == &X86::FR64RegClass || DstRC == &X86::FR64XRegClass) &&
668          (SrcRC == &X86::VR128RegClass || SrcRC == &X86::VR128XRegClass);
669 }
670 
selectTurnIntoCOPY(MachineInstr & I,MachineRegisterInfo & MRI,const unsigned DstReg,const TargetRegisterClass * DstRC,const unsigned SrcReg,const TargetRegisterClass * SrcRC) const671 bool X86InstructionSelector::selectTurnIntoCOPY(
672     MachineInstr &I, MachineRegisterInfo &MRI, const unsigned DstReg,
673     const TargetRegisterClass *DstRC, const unsigned SrcReg,
674     const TargetRegisterClass *SrcRC) const {
675 
676   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
677       !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
678     LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
679                       << " operand\n");
680     return false;
681   }
682   I.setDesc(TII.get(X86::COPY));
683   return true;
684 }
685 
selectTruncOrPtrToInt(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const686 bool X86InstructionSelector::selectTruncOrPtrToInt(MachineInstr &I,
687                                                    MachineRegisterInfo &MRI,
688                                                    MachineFunction &MF) const {
689   assert((I.getOpcode() == TargetOpcode::G_TRUNC ||
690           I.getOpcode() == TargetOpcode::G_PTRTOINT) &&
691          "unexpected instruction");
692 
693   const unsigned DstReg = I.getOperand(0).getReg();
694   const unsigned SrcReg = I.getOperand(1).getReg();
695 
696   const LLT DstTy = MRI.getType(DstReg);
697   const LLT SrcTy = MRI.getType(SrcReg);
698 
699   const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
700   const RegisterBank &SrcRB = *RBI.getRegBank(SrcReg, MRI, TRI);
701 
702   if (DstRB.getID() != SrcRB.getID()) {
703     LLVM_DEBUG(dbgs() << TII.getName(I.getOpcode())
704                       << " input/output on different banks\n");
705     return false;
706   }
707 
708   const TargetRegisterClass *DstRC = getRegClass(DstTy, DstRB);
709   const TargetRegisterClass *SrcRC = getRegClass(SrcTy, SrcRB);
710 
711   if (!DstRC || !SrcRC)
712     return false;
713 
714   // If that's truncation of the value that lives on the vector class and goes
715   // into the floating class, just replace it with copy, as we are able to
716   // select it as a regular move.
717   if (canTurnIntoCOPY(DstRC, SrcRC))
718     return selectTurnIntoCOPY(I, MRI, DstReg, DstRC, SrcReg, SrcRC);
719 
720   if (DstRB.getID() != X86::GPRRegBankID)
721     return false;
722 
723   unsigned SubIdx;
724   if (DstRC == SrcRC) {
725     // Nothing to be done
726     SubIdx = X86::NoSubRegister;
727   } else if (DstRC == &X86::GR32RegClass) {
728     SubIdx = X86::sub_32bit;
729   } else if (DstRC == &X86::GR16RegClass) {
730     SubIdx = X86::sub_16bit;
731   } else if (DstRC == &X86::GR8RegClass) {
732     SubIdx = X86::sub_8bit;
733   } else {
734     return false;
735   }
736 
737   SrcRC = TRI.getSubClassWithSubReg(SrcRC, SubIdx);
738 
739   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
740       !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
741     LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
742                       << "\n");
743     return false;
744   }
745 
746   I.getOperand(1).setSubReg(SubIdx);
747 
748   I.setDesc(TII.get(X86::COPY));
749   return true;
750 }
751 
selectZext(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const752 bool X86InstructionSelector::selectZext(MachineInstr &I,
753                                         MachineRegisterInfo &MRI,
754                                         MachineFunction &MF) const {
755   assert((I.getOpcode() == TargetOpcode::G_ZEXT) && "unexpected instruction");
756 
757   const unsigned DstReg = I.getOperand(0).getReg();
758   const unsigned SrcReg = I.getOperand(1).getReg();
759 
760   const LLT DstTy = MRI.getType(DstReg);
761   const LLT SrcTy = MRI.getType(SrcReg);
762 
763   assert(!(SrcTy == LLT::scalar(8) && DstTy == LLT::scalar(32)) &&
764          "8=>32 Zext is handled by tablegen");
765   assert(!(SrcTy == LLT::scalar(16) && DstTy == LLT::scalar(32)) &&
766          "16=>32 Zext is handled by tablegen");
767 
768   const static struct ZextEntry {
769     LLT SrcTy;
770     LLT DstTy;
771     unsigned MovOp;
772     bool NeedSubregToReg;
773   } OpTable[] = {
774       {LLT::scalar(8), LLT::scalar(16), X86::MOVZX16rr8, false},  // i8  => i16
775       {LLT::scalar(8), LLT::scalar(64), X86::MOVZX32rr8, true},   // i8  => i64
776       {LLT::scalar(16), LLT::scalar(64), X86::MOVZX32rr16, true}, // i16 => i64
777       {LLT::scalar(32), LLT::scalar(64), 0, true}                 // i32 => i64
778   };
779 
780   auto ZextEntryIt =
781       std::find_if(std::begin(OpTable), std::end(OpTable),
782                    [SrcTy, DstTy](const ZextEntry &El) {
783                      return El.DstTy == DstTy && El.SrcTy == SrcTy;
784                    });
785 
786   // Here we try to select Zext into a MOVZ and/or SUBREG_TO_REG instruction.
787   if (ZextEntryIt != std::end(OpTable)) {
788     const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
789     const RegisterBank &SrcRB = *RBI.getRegBank(SrcReg, MRI, TRI);
790     const TargetRegisterClass *DstRC = getRegClass(DstTy, DstRB);
791     const TargetRegisterClass *SrcRC = getRegClass(SrcTy, SrcRB);
792 
793     if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
794         !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
795       LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
796                         << " operand\n");
797       return false;
798     }
799 
800     unsigned TransitRegTo = DstReg;
801     unsigned TransitRegFrom = SrcReg;
802     if (ZextEntryIt->MovOp) {
803       // If we select Zext into MOVZ + SUBREG_TO_REG, we need to have
804       // a transit register in between: create it here.
805       if (ZextEntryIt->NeedSubregToReg) {
806         TransitRegFrom = MRI.createVirtualRegister(
807             getRegClass(LLT::scalar(32), DstReg, MRI));
808         TransitRegTo = TransitRegFrom;
809       }
810 
811       BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(ZextEntryIt->MovOp))
812           .addDef(TransitRegTo)
813           .addReg(SrcReg);
814     }
815     if (ZextEntryIt->NeedSubregToReg) {
816       BuildMI(*I.getParent(), I, I.getDebugLoc(),
817               TII.get(TargetOpcode::SUBREG_TO_REG))
818           .addDef(DstReg)
819           .addImm(0)
820           .addReg(TransitRegFrom)
821           .addImm(X86::sub_32bit);
822     }
823     I.eraseFromParent();
824     return true;
825   }
826 
827   if (SrcTy != LLT::scalar(1))
828     return false;
829 
830   unsigned AndOpc;
831   if (DstTy == LLT::scalar(8))
832     AndOpc = X86::AND8ri;
833   else if (DstTy == LLT::scalar(16))
834     AndOpc = X86::AND16ri8;
835   else if (DstTy == LLT::scalar(32))
836     AndOpc = X86::AND32ri8;
837   else if (DstTy == LLT::scalar(64))
838     AndOpc = X86::AND64ri8;
839   else
840     return false;
841 
842   unsigned DefReg = SrcReg;
843   if (DstTy != LLT::scalar(8)) {
844     DefReg = MRI.createVirtualRegister(getRegClass(DstTy, DstReg, MRI));
845     BuildMI(*I.getParent(), I, I.getDebugLoc(),
846             TII.get(TargetOpcode::SUBREG_TO_REG), DefReg)
847         .addImm(0)
848         .addReg(SrcReg)
849         .addImm(X86::sub_8bit);
850   }
851 
852   MachineInstr &AndInst =
853       *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(AndOpc), DstReg)
854            .addReg(DefReg)
855            .addImm(1);
856 
857   constrainSelectedInstRegOperands(AndInst, TII, TRI, RBI);
858 
859   I.eraseFromParent();
860   return true;
861 }
862 
selectAnyext(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const863 bool X86InstructionSelector::selectAnyext(MachineInstr &I,
864                                           MachineRegisterInfo &MRI,
865                                           MachineFunction &MF) const {
866   assert((I.getOpcode() == TargetOpcode::G_ANYEXT) && "unexpected instruction");
867 
868   const unsigned DstReg = I.getOperand(0).getReg();
869   const unsigned SrcReg = I.getOperand(1).getReg();
870 
871   const LLT DstTy = MRI.getType(DstReg);
872   const LLT SrcTy = MRI.getType(SrcReg);
873 
874   const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
875   const RegisterBank &SrcRB = *RBI.getRegBank(SrcReg, MRI, TRI);
876 
877   assert(DstRB.getID() == SrcRB.getID() &&
878          "G_ANYEXT input/output on different banks\n");
879 
880   assert(DstTy.getSizeInBits() > SrcTy.getSizeInBits() &&
881          "G_ANYEXT incorrect operand size");
882 
883   const TargetRegisterClass *DstRC = getRegClass(DstTy, DstRB);
884   const TargetRegisterClass *SrcRC = getRegClass(SrcTy, SrcRB);
885 
886   // If that's ANY_EXT of the value that lives on the floating class and goes
887   // into the vector class, just replace it with copy, as we are able to select
888   // it as a regular move.
889   if (canTurnIntoCOPY(SrcRC, DstRC))
890     return selectTurnIntoCOPY(I, MRI, SrcReg, SrcRC, DstReg, DstRC);
891 
892   if (DstRB.getID() != X86::GPRRegBankID)
893     return false;
894 
895   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
896       !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
897     LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
898                       << " operand\n");
899     return false;
900   }
901 
902   if (SrcRC == DstRC) {
903     I.setDesc(TII.get(X86::COPY));
904     return true;
905   }
906 
907   BuildMI(*I.getParent(), I, I.getDebugLoc(),
908           TII.get(TargetOpcode::SUBREG_TO_REG))
909       .addDef(DstReg)
910       .addImm(0)
911       .addReg(SrcReg)
912       .addImm(getSubRegIndex(SrcRC));
913 
914   I.eraseFromParent();
915   return true;
916 }
917 
selectCmp(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const918 bool X86InstructionSelector::selectCmp(MachineInstr &I,
919                                        MachineRegisterInfo &MRI,
920                                        MachineFunction &MF) const {
921   assert((I.getOpcode() == TargetOpcode::G_ICMP) && "unexpected instruction");
922 
923   X86::CondCode CC;
924   bool SwapArgs;
925   std::tie(CC, SwapArgs) = X86::getX86ConditionCode(
926       (CmpInst::Predicate)I.getOperand(1).getPredicate());
927   unsigned OpSet = X86::getSETFromCond(CC);
928 
929   unsigned LHS = I.getOperand(2).getReg();
930   unsigned RHS = I.getOperand(3).getReg();
931 
932   if (SwapArgs)
933     std::swap(LHS, RHS);
934 
935   unsigned OpCmp;
936   LLT Ty = MRI.getType(LHS);
937 
938   switch (Ty.getSizeInBits()) {
939   default:
940     return false;
941   case 8:
942     OpCmp = X86::CMP8rr;
943     break;
944   case 16:
945     OpCmp = X86::CMP16rr;
946     break;
947   case 32:
948     OpCmp = X86::CMP32rr;
949     break;
950   case 64:
951     OpCmp = X86::CMP64rr;
952     break;
953   }
954 
955   MachineInstr &CmpInst =
956       *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(OpCmp))
957            .addReg(LHS)
958            .addReg(RHS);
959 
960   MachineInstr &SetInst = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
961                                    TII.get(OpSet), I.getOperand(0).getReg());
962 
963   constrainSelectedInstRegOperands(CmpInst, TII, TRI, RBI);
964   constrainSelectedInstRegOperands(SetInst, TII, TRI, RBI);
965 
966   I.eraseFromParent();
967   return true;
968 }
969 
selectUadde(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const970 bool X86InstructionSelector::selectUadde(MachineInstr &I,
971                                          MachineRegisterInfo &MRI,
972                                          MachineFunction &MF) const {
973   assert((I.getOpcode() == TargetOpcode::G_UADDE) && "unexpected instruction");
974 
975   const unsigned DstReg = I.getOperand(0).getReg();
976   const unsigned CarryOutReg = I.getOperand(1).getReg();
977   const unsigned Op0Reg = I.getOperand(2).getReg();
978   const unsigned Op1Reg = I.getOperand(3).getReg();
979   unsigned CarryInReg = I.getOperand(4).getReg();
980 
981   const LLT DstTy = MRI.getType(DstReg);
982 
983   if (DstTy != LLT::scalar(32))
984     return false;
985 
986   // find CarryIn def instruction.
987   MachineInstr *Def = MRI.getVRegDef(CarryInReg);
988   while (Def->getOpcode() == TargetOpcode::G_TRUNC) {
989     CarryInReg = Def->getOperand(1).getReg();
990     Def = MRI.getVRegDef(CarryInReg);
991   }
992 
993   unsigned Opcode;
994   if (Def->getOpcode() == TargetOpcode::G_UADDE) {
995     // carry set by prev ADD.
996 
997     BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::COPY), X86::EFLAGS)
998         .addReg(CarryInReg);
999 
1000     if (!RBI.constrainGenericRegister(CarryInReg, X86::GR32RegClass, MRI))
1001       return false;
1002 
1003     Opcode = X86::ADC32rr;
1004   } else if (auto val = getConstantVRegVal(CarryInReg, MRI)) {
1005     // carry is constant, support only 0.
1006     if (*val != 0)
1007       return false;
1008 
1009     Opcode = X86::ADD32rr;
1010   } else
1011     return false;
1012 
1013   MachineInstr &AddInst =
1014       *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode), DstReg)
1015            .addReg(Op0Reg)
1016            .addReg(Op1Reg);
1017 
1018   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::COPY), CarryOutReg)
1019       .addReg(X86::EFLAGS);
1020 
1021   if (!constrainSelectedInstRegOperands(AddInst, TII, TRI, RBI) ||
1022       !RBI.constrainGenericRegister(CarryOutReg, X86::GR32RegClass, MRI))
1023     return false;
1024 
1025   I.eraseFromParent();
1026   return true;
1027 }
1028 
selectExtract(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1029 bool X86InstructionSelector::selectExtract(MachineInstr &I,
1030                                            MachineRegisterInfo &MRI,
1031                                            MachineFunction &MF) const {
1032   assert((I.getOpcode() == TargetOpcode::G_EXTRACT) &&
1033          "unexpected instruction");
1034 
1035   const unsigned DstReg = I.getOperand(0).getReg();
1036   const unsigned SrcReg = I.getOperand(1).getReg();
1037   int64_t Index = I.getOperand(2).getImm();
1038 
1039   const LLT DstTy = MRI.getType(DstReg);
1040   const LLT SrcTy = MRI.getType(SrcReg);
1041 
1042   // Meanwile handle vector type only.
1043   if (!DstTy.isVector())
1044     return false;
1045 
1046   if (Index % DstTy.getSizeInBits() != 0)
1047     return false; // Not extract subvector.
1048 
1049   if (Index == 0) {
1050     // Replace by extract subreg copy.
1051     if (!emitExtractSubreg(DstReg, SrcReg, I, MRI, MF))
1052       return false;
1053 
1054     I.eraseFromParent();
1055     return true;
1056   }
1057 
1058   bool HasAVX = STI.hasAVX();
1059   bool HasAVX512 = STI.hasAVX512();
1060   bool HasVLX = STI.hasVLX();
1061 
1062   if (SrcTy.getSizeInBits() == 256 && DstTy.getSizeInBits() == 128) {
1063     if (HasVLX)
1064       I.setDesc(TII.get(X86::VEXTRACTF32x4Z256rr));
1065     else if (HasAVX)
1066       I.setDesc(TII.get(X86::VEXTRACTF128rr));
1067     else
1068       return false;
1069   } else if (SrcTy.getSizeInBits() == 512 && HasAVX512) {
1070     if (DstTy.getSizeInBits() == 128)
1071       I.setDesc(TII.get(X86::VEXTRACTF32x4Zrr));
1072     else if (DstTy.getSizeInBits() == 256)
1073       I.setDesc(TII.get(X86::VEXTRACTF64x4Zrr));
1074     else
1075       return false;
1076   } else
1077     return false;
1078 
1079   // Convert to X86 VEXTRACT immediate.
1080   Index = Index / DstTy.getSizeInBits();
1081   I.getOperand(2).setImm(Index);
1082 
1083   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
1084 }
1085 
emitExtractSubreg(unsigned DstReg,unsigned SrcReg,MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1086 bool X86InstructionSelector::emitExtractSubreg(unsigned DstReg, unsigned SrcReg,
1087                                                MachineInstr &I,
1088                                                MachineRegisterInfo &MRI,
1089                                                MachineFunction &MF) const {
1090   const LLT DstTy = MRI.getType(DstReg);
1091   const LLT SrcTy = MRI.getType(SrcReg);
1092   unsigned SubIdx = X86::NoSubRegister;
1093 
1094   if (!DstTy.isVector() || !SrcTy.isVector())
1095     return false;
1096 
1097   assert(SrcTy.getSizeInBits() > DstTy.getSizeInBits() &&
1098          "Incorrect Src/Dst register size");
1099 
1100   if (DstTy.getSizeInBits() == 128)
1101     SubIdx = X86::sub_xmm;
1102   else if (DstTy.getSizeInBits() == 256)
1103     SubIdx = X86::sub_ymm;
1104   else
1105     return false;
1106 
1107   const TargetRegisterClass *DstRC = getRegClass(DstTy, DstReg, MRI);
1108   const TargetRegisterClass *SrcRC = getRegClass(SrcTy, SrcReg, MRI);
1109 
1110   SrcRC = TRI.getSubClassWithSubReg(SrcRC, SubIdx);
1111 
1112   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
1113       !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
1114     LLVM_DEBUG(dbgs() << "Failed to constrain G_TRUNC\n");
1115     return false;
1116   }
1117 
1118   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::COPY), DstReg)
1119       .addReg(SrcReg, 0, SubIdx);
1120 
1121   return true;
1122 }
1123 
emitInsertSubreg(unsigned DstReg,unsigned SrcReg,MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1124 bool X86InstructionSelector::emitInsertSubreg(unsigned DstReg, unsigned SrcReg,
1125                                               MachineInstr &I,
1126                                               MachineRegisterInfo &MRI,
1127                                               MachineFunction &MF) const {
1128   const LLT DstTy = MRI.getType(DstReg);
1129   const LLT SrcTy = MRI.getType(SrcReg);
1130   unsigned SubIdx = X86::NoSubRegister;
1131 
1132   // TODO: support scalar types
1133   if (!DstTy.isVector() || !SrcTy.isVector())
1134     return false;
1135 
1136   assert(SrcTy.getSizeInBits() < DstTy.getSizeInBits() &&
1137          "Incorrect Src/Dst register size");
1138 
1139   if (SrcTy.getSizeInBits() == 128)
1140     SubIdx = X86::sub_xmm;
1141   else if (SrcTy.getSizeInBits() == 256)
1142     SubIdx = X86::sub_ymm;
1143   else
1144     return false;
1145 
1146   const TargetRegisterClass *SrcRC = getRegClass(SrcTy, SrcReg, MRI);
1147   const TargetRegisterClass *DstRC = getRegClass(DstTy, DstReg, MRI);
1148 
1149   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, MRI) ||
1150       !RBI.constrainGenericRegister(DstReg, *DstRC, MRI)) {
1151     LLVM_DEBUG(dbgs() << "Failed to constrain INSERT_SUBREG\n");
1152     return false;
1153   }
1154 
1155   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::COPY))
1156       .addReg(DstReg, RegState::DefineNoRead, SubIdx)
1157       .addReg(SrcReg);
1158 
1159   return true;
1160 }
1161 
selectInsert(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1162 bool X86InstructionSelector::selectInsert(MachineInstr &I,
1163                                           MachineRegisterInfo &MRI,
1164                                           MachineFunction &MF) const {
1165   assert((I.getOpcode() == TargetOpcode::G_INSERT) && "unexpected instruction");
1166 
1167   const unsigned DstReg = I.getOperand(0).getReg();
1168   const unsigned SrcReg = I.getOperand(1).getReg();
1169   const unsigned InsertReg = I.getOperand(2).getReg();
1170   int64_t Index = I.getOperand(3).getImm();
1171 
1172   const LLT DstTy = MRI.getType(DstReg);
1173   const LLT InsertRegTy = MRI.getType(InsertReg);
1174 
1175   // Meanwile handle vector type only.
1176   if (!DstTy.isVector())
1177     return false;
1178 
1179   if (Index % InsertRegTy.getSizeInBits() != 0)
1180     return false; // Not insert subvector.
1181 
1182   if (Index == 0 && MRI.getVRegDef(SrcReg)->isImplicitDef()) {
1183     // Replace by subreg copy.
1184     if (!emitInsertSubreg(DstReg, InsertReg, I, MRI, MF))
1185       return false;
1186 
1187     I.eraseFromParent();
1188     return true;
1189   }
1190 
1191   bool HasAVX = STI.hasAVX();
1192   bool HasAVX512 = STI.hasAVX512();
1193   bool HasVLX = STI.hasVLX();
1194 
1195   if (DstTy.getSizeInBits() == 256 && InsertRegTy.getSizeInBits() == 128) {
1196     if (HasVLX)
1197       I.setDesc(TII.get(X86::VINSERTF32x4Z256rr));
1198     else if (HasAVX)
1199       I.setDesc(TII.get(X86::VINSERTF128rr));
1200     else
1201       return false;
1202   } else if (DstTy.getSizeInBits() == 512 && HasAVX512) {
1203     if (InsertRegTy.getSizeInBits() == 128)
1204       I.setDesc(TII.get(X86::VINSERTF32x4Zrr));
1205     else if (InsertRegTy.getSizeInBits() == 256)
1206       I.setDesc(TII.get(X86::VINSERTF64x4Zrr));
1207     else
1208       return false;
1209   } else
1210     return false;
1211 
1212   // Convert to X86 VINSERT immediate.
1213   Index = Index / InsertRegTy.getSizeInBits();
1214 
1215   I.getOperand(3).setImm(Index);
1216 
1217   return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
1218 }
1219 
selectUnmergeValues(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF,CodeGenCoverage & CoverageInfo) const1220 bool X86InstructionSelector::selectUnmergeValues(
1221     MachineInstr &I, MachineRegisterInfo &MRI, MachineFunction &MF,
1222     CodeGenCoverage &CoverageInfo) const {
1223   assert((I.getOpcode() == TargetOpcode::G_UNMERGE_VALUES) &&
1224          "unexpected instruction");
1225 
1226   // Split to extracts.
1227   unsigned NumDefs = I.getNumOperands() - 1;
1228   unsigned SrcReg = I.getOperand(NumDefs).getReg();
1229   unsigned DefSize = MRI.getType(I.getOperand(0).getReg()).getSizeInBits();
1230 
1231   for (unsigned Idx = 0; Idx < NumDefs; ++Idx) {
1232     MachineInstr &ExtrInst =
1233         *BuildMI(*I.getParent(), I, I.getDebugLoc(),
1234                  TII.get(TargetOpcode::G_EXTRACT), I.getOperand(Idx).getReg())
1235              .addReg(SrcReg)
1236              .addImm(Idx * DefSize);
1237 
1238     if (!select(ExtrInst, CoverageInfo))
1239       return false;
1240   }
1241 
1242   I.eraseFromParent();
1243   return true;
1244 }
1245 
selectMergeValues(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF,CodeGenCoverage & CoverageInfo) const1246 bool X86InstructionSelector::selectMergeValues(
1247     MachineInstr &I, MachineRegisterInfo &MRI, MachineFunction &MF,
1248     CodeGenCoverage &CoverageInfo) const {
1249   assert((I.getOpcode() == TargetOpcode::G_MERGE_VALUES) &&
1250          "unexpected instruction");
1251 
1252   // Split to inserts.
1253   unsigned DstReg = I.getOperand(0).getReg();
1254   unsigned SrcReg0 = I.getOperand(1).getReg();
1255 
1256   const LLT DstTy = MRI.getType(DstReg);
1257   const LLT SrcTy = MRI.getType(SrcReg0);
1258   unsigned SrcSize = SrcTy.getSizeInBits();
1259 
1260   const RegisterBank &RegBank = *RBI.getRegBank(DstReg, MRI, TRI);
1261 
1262   // For the first src use insertSubReg.
1263   unsigned DefReg = MRI.createGenericVirtualRegister(DstTy);
1264   MRI.setRegBank(DefReg, RegBank);
1265   if (!emitInsertSubreg(DefReg, I.getOperand(1).getReg(), I, MRI, MF))
1266     return false;
1267 
1268   for (unsigned Idx = 2; Idx < I.getNumOperands(); ++Idx) {
1269     unsigned Tmp = MRI.createGenericVirtualRegister(DstTy);
1270     MRI.setRegBank(Tmp, RegBank);
1271 
1272     MachineInstr &InsertInst = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
1273                                         TII.get(TargetOpcode::G_INSERT), Tmp)
1274                                     .addReg(DefReg)
1275                                     .addReg(I.getOperand(Idx).getReg())
1276                                     .addImm((Idx - 1) * SrcSize);
1277 
1278     DefReg = Tmp;
1279 
1280     if (!select(InsertInst, CoverageInfo))
1281       return false;
1282   }
1283 
1284   MachineInstr &CopyInst = *BuildMI(*I.getParent(), I, I.getDebugLoc(),
1285                                     TII.get(TargetOpcode::COPY), DstReg)
1286                                 .addReg(DefReg);
1287 
1288   if (!select(CopyInst, CoverageInfo))
1289     return false;
1290 
1291   I.eraseFromParent();
1292   return true;
1293 }
1294 
selectCondBranch(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1295 bool X86InstructionSelector::selectCondBranch(MachineInstr &I,
1296                                               MachineRegisterInfo &MRI,
1297                                               MachineFunction &MF) const {
1298   assert((I.getOpcode() == TargetOpcode::G_BRCOND) && "unexpected instruction");
1299 
1300   const unsigned CondReg = I.getOperand(0).getReg();
1301   MachineBasicBlock *DestMBB = I.getOperand(1).getMBB();
1302 
1303   MachineInstr &TestInst =
1304       *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::TEST8ri))
1305            .addReg(CondReg)
1306            .addImm(1);
1307   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(X86::JNE_1))
1308       .addMBB(DestMBB);
1309 
1310   constrainSelectedInstRegOperands(TestInst, TII, TRI, RBI);
1311 
1312   I.eraseFromParent();
1313   return true;
1314 }
1315 
materializeFP(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1316 bool X86InstructionSelector::materializeFP(MachineInstr &I,
1317                                            MachineRegisterInfo &MRI,
1318                                            MachineFunction &MF) const {
1319   assert((I.getOpcode() == TargetOpcode::G_FCONSTANT) &&
1320          "unexpected instruction");
1321 
1322   // Can't handle alternate code models yet.
1323   CodeModel::Model CM = TM.getCodeModel();
1324   if (CM != CodeModel::Small && CM != CodeModel::Large)
1325     return false;
1326 
1327   const unsigned DstReg = I.getOperand(0).getReg();
1328   const LLT DstTy = MRI.getType(DstReg);
1329   const RegisterBank &RegBank = *RBI.getRegBank(DstReg, MRI, TRI);
1330   unsigned Align = DstTy.getSizeInBits();
1331   const DebugLoc &DbgLoc = I.getDebugLoc();
1332 
1333   unsigned Opc = getLoadStoreOp(DstTy, RegBank, TargetOpcode::G_LOAD, Align);
1334 
1335   // Create the load from the constant pool.
1336   const ConstantFP *CFP = I.getOperand(1).getFPImm();
1337   unsigned CPI = MF.getConstantPool()->getConstantPoolIndex(CFP, Align);
1338   MachineInstr *LoadInst = nullptr;
1339   unsigned char OpFlag = STI.classifyLocalReference(nullptr);
1340 
1341   if (CM == CodeModel::Large && STI.is64Bit()) {
1342     // Under X86-64 non-small code model, GV (and friends) are 64-bits, so
1343     // they cannot be folded into immediate fields.
1344 
1345     unsigned AddrReg = MRI.createVirtualRegister(&X86::GR64RegClass);
1346     BuildMI(*I.getParent(), I, DbgLoc, TII.get(X86::MOV64ri), AddrReg)
1347         .addConstantPoolIndex(CPI, 0, OpFlag);
1348 
1349     MachineMemOperand *MMO = MF.getMachineMemOperand(
1350         MachinePointerInfo::getConstantPool(MF), MachineMemOperand::MOLoad,
1351         MF.getDataLayout().getPointerSize(), Align);
1352 
1353     LoadInst =
1354         addDirectMem(BuildMI(*I.getParent(), I, DbgLoc, TII.get(Opc), DstReg),
1355                      AddrReg)
1356             .addMemOperand(MMO);
1357 
1358   } else if (CM == CodeModel::Small || !STI.is64Bit()) {
1359     // Handle the case when globals fit in our immediate field.
1360     // This is true for X86-32 always and X86-64 when in -mcmodel=small mode.
1361 
1362     // x86-32 PIC requires a PIC base register for constant pools.
1363     unsigned PICBase = 0;
1364     if (OpFlag == X86II::MO_PIC_BASE_OFFSET || OpFlag == X86II::MO_GOTOFF) {
1365       // PICBase can be allocated by TII.getGlobalBaseReg(&MF).
1366       // In DAGISEL the code that initialize it generated by the CGBR pass.
1367       return false; // TODO support the mode.
1368     } else if (STI.is64Bit() && TM.getCodeModel() == CodeModel::Small)
1369       PICBase = X86::RIP;
1370 
1371     LoadInst = addConstantPoolReference(
1372         BuildMI(*I.getParent(), I, DbgLoc, TII.get(Opc), DstReg), CPI, PICBase,
1373         OpFlag);
1374   } else
1375     return false;
1376 
1377   constrainSelectedInstRegOperands(*LoadInst, TII, TRI, RBI);
1378   I.eraseFromParent();
1379   return true;
1380 }
1381 
selectImplicitDefOrPHI(MachineInstr & I,MachineRegisterInfo & MRI) const1382 bool X86InstructionSelector::selectImplicitDefOrPHI(
1383     MachineInstr &I, MachineRegisterInfo &MRI) const {
1384   assert((I.getOpcode() == TargetOpcode::G_IMPLICIT_DEF ||
1385           I.getOpcode() == TargetOpcode::G_PHI) &&
1386          "unexpected instruction");
1387 
1388   unsigned DstReg = I.getOperand(0).getReg();
1389 
1390   if (!MRI.getRegClassOrNull(DstReg)) {
1391     const LLT DstTy = MRI.getType(DstReg);
1392     const TargetRegisterClass *RC = getRegClass(DstTy, DstReg, MRI);
1393 
1394     if (!RBI.constrainGenericRegister(DstReg, *RC, MRI)) {
1395       LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
1396                         << " operand\n");
1397       return false;
1398     }
1399   }
1400 
1401   if (I.getOpcode() == TargetOpcode::G_IMPLICIT_DEF)
1402     I.setDesc(TII.get(X86::IMPLICIT_DEF));
1403   else
1404     I.setDesc(TII.get(X86::PHI));
1405 
1406   return true;
1407 }
1408 
1409 // Currently GlobalIsel TableGen generates patterns for shift imm and shift 1,
1410 // but with shiftCount i8. In G_LSHR/G_ASHR/G_SHL like LLVM-IR both arguments
1411 // has the same type, so for now only shift i8 can use auto generated
1412 // TableGen patterns.
selectShift(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1413 bool X86InstructionSelector::selectShift(MachineInstr &I,
1414                                          MachineRegisterInfo &MRI,
1415                                          MachineFunction &MF) const {
1416 
1417   assert((I.getOpcode() == TargetOpcode::G_SHL ||
1418           I.getOpcode() == TargetOpcode::G_ASHR ||
1419           I.getOpcode() == TargetOpcode::G_LSHR) &&
1420          "unexpected instruction");
1421 
1422   unsigned DstReg = I.getOperand(0).getReg();
1423   const LLT DstTy = MRI.getType(DstReg);
1424   const RegisterBank &DstRB = *RBI.getRegBank(DstReg, MRI, TRI);
1425 
1426   const static struct ShiftEntry {
1427     unsigned SizeInBits;
1428     unsigned CReg;
1429     unsigned OpLSHR;
1430     unsigned OpASHR;
1431     unsigned OpSHL;
1432   } OpTable[] = {
1433       {8, X86::CL, X86::SHR8rCL, X86::SAR8rCL, X86::SHL8rCL},      // i8
1434       {16, X86::CX, X86::SHR16rCL, X86::SAR16rCL, X86::SHL16rCL},  // i16
1435       {32, X86::ECX, X86::SHR32rCL, X86::SAR32rCL, X86::SHL32rCL}, // i32
1436       {64, X86::RCX, X86::SHR64rCL, X86::SAR64rCL, X86::SHL64rCL}  // i64
1437   };
1438 
1439   if (DstRB.getID() != X86::GPRRegBankID)
1440     return false;
1441 
1442   auto ShiftEntryIt = std::find_if(
1443       std::begin(OpTable), std::end(OpTable), [DstTy](const ShiftEntry &El) {
1444         return El.SizeInBits == DstTy.getSizeInBits();
1445       });
1446   if (ShiftEntryIt == std::end(OpTable))
1447     return false;
1448 
1449   unsigned CReg = ShiftEntryIt->CReg;
1450   unsigned Opcode = 0;
1451   switch (I.getOpcode()) {
1452   case TargetOpcode::G_SHL:
1453     Opcode = ShiftEntryIt->OpSHL;
1454     break;
1455   case TargetOpcode::G_ASHR:
1456     Opcode = ShiftEntryIt->OpASHR;
1457     break;
1458   case TargetOpcode::G_LSHR:
1459     Opcode = ShiftEntryIt->OpLSHR;
1460     break;
1461   default:
1462     return false;
1463   }
1464 
1465   unsigned Op0Reg = I.getOperand(1).getReg();
1466   unsigned Op1Reg = I.getOperand(2).getReg();
1467 
1468   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(TargetOpcode::COPY),
1469           ShiftEntryIt->CReg)
1470       .addReg(Op1Reg);
1471 
1472   // The shift instruction uses X86::CL. If we defined a super-register
1473   // of X86::CL, emit a subreg KILL to precisely describe what we're doing here.
1474   if (CReg != X86::CL)
1475     BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(TargetOpcode::KILL),
1476             X86::CL)
1477         .addReg(CReg, RegState::Kill);
1478 
1479   MachineInstr &ShiftInst =
1480       *BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(Opcode), DstReg)
1481            .addReg(Op0Reg);
1482 
1483   constrainSelectedInstRegOperands(ShiftInst, TII, TRI, RBI);
1484   I.eraseFromParent();
1485   return true;
1486 }
1487 
selectSDiv(MachineInstr & I,MachineRegisterInfo & MRI,MachineFunction & MF) const1488 bool X86InstructionSelector::selectSDiv(MachineInstr &I,
1489                                         MachineRegisterInfo &MRI,
1490                                         MachineFunction &MF) const {
1491 
1492   assert(I.getOpcode() == TargetOpcode::G_SDIV && "unexpected instruction");
1493 
1494   const unsigned DstReg = I.getOperand(0).getReg();
1495   const unsigned DividentReg = I.getOperand(1).getReg();
1496   const unsigned DiviserReg = I.getOperand(2).getReg();
1497 
1498   const LLT RegTy = MRI.getType(DstReg);
1499   assert(RegTy == MRI.getType(DividentReg) &&
1500          RegTy == MRI.getType(DiviserReg) &&
1501          "Arguments and return value types must match");
1502 
1503   const RegisterBank &RegRB = *RBI.getRegBank(DstReg, MRI, TRI);
1504 
1505   // For the X86 IDIV instruction, in most cases the dividend
1506   // (numerator) must be in a specific register pair highreg:lowreg,
1507   // producing the quotient in lowreg and the remainder in highreg.
1508   // For most data types, to set up the instruction, the dividend is
1509   // copied into lowreg, and lowreg is sign-extended into highreg.  The
1510   // exception is i8, where the dividend is defined as a single register rather
1511   // than a register pair, and we therefore directly sign-extend the dividend
1512   // into lowreg, instead of copying, and ignore the highreg.
1513   const static struct SDivEntry {
1514     unsigned SizeInBits;
1515     unsigned QuotientReg;
1516     unsigned DividentRegUpper;
1517     unsigned DividentRegLower;
1518     unsigned OpSignExtend;
1519     unsigned OpCopy;
1520     unsigned OpDiv;
1521   } OpTable[] = {
1522       {8, X86::AL, X86::NoRegister, X86::AX, 0, X86::MOVSX16rr8,
1523        X86::IDIV8r}, // i8
1524       {16, X86::AX, X86::DX, X86::AX, X86::CWD, TargetOpcode::COPY,
1525        X86::IDIV16r}, // i16
1526       {32, X86::EAX, X86::EDX, X86::EAX, X86::CDQ, TargetOpcode::COPY,
1527        X86::IDIV32r}, // i32
1528       {64, X86::RAX, X86::RDX, X86::RAX, X86::CQO, TargetOpcode::COPY,
1529        X86::IDIV64r} // i64
1530   };
1531 
1532   if (RegRB.getID() != X86::GPRRegBankID)
1533     return false;
1534 
1535   auto SDivEntryIt = std::find_if(
1536       std::begin(OpTable), std::end(OpTable), [RegTy](const SDivEntry &El) {
1537     return El.SizeInBits == RegTy.getSizeInBits();
1538       });
1539 
1540   if (SDivEntryIt == std::end(OpTable))
1541     return false;
1542 
1543   const TargetRegisterClass *RegRC = getRegClass(RegTy, RegRB);
1544   if (!RBI.constrainGenericRegister(DividentReg, *RegRC, MRI) ||
1545       !RBI.constrainGenericRegister(DiviserReg, *RegRC, MRI) ||
1546       !RBI.constrainGenericRegister(DstReg, *RegRC, MRI)) {
1547     LLVM_DEBUG(dbgs() << "Failed to constrain " << TII.getName(I.getOpcode())
1548                       << " operand\n");
1549     return false;
1550   }
1551 
1552   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SDivEntryIt->OpCopy),
1553           SDivEntryIt->DividentRegLower)
1554       .addReg(DividentReg);
1555   if (SDivEntryIt->DividentRegUpper != X86::NoRegister)
1556     BuildMI(*I.getParent(), I, I.getDebugLoc(),
1557             TII.get(SDivEntryIt->OpSignExtend));
1558   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(SDivEntryIt->OpDiv))
1559       .addReg(DiviserReg);
1560   BuildMI(*I.getParent(), I, I.getDebugLoc(), TII.get(TargetOpcode::COPY),
1561           DstReg)
1562       .addReg(SDivEntryIt->QuotientReg);
1563 
1564   I.eraseFromParent();
1565   return true;
1566 }
1567 
1568 InstructionSelector *
createX86InstructionSelector(const X86TargetMachine & TM,X86Subtarget & Subtarget,X86RegisterBankInfo & RBI)1569 llvm::createX86InstructionSelector(const X86TargetMachine &TM,
1570                                    X86Subtarget &Subtarget,
1571                                    X86RegisterBankInfo &RBI) {
1572   return new X86InstructionSelector(TM, Subtarget, RBI);
1573 }
1574