1 //===- AMDGPUInstructionSelector.cpp ----------------------------*- C++ -*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 /// This file implements the targeting of the InstructionSelector class for
10 /// AMDGPU.
11 /// \todo This should be generated by TableGen.
12 //===----------------------------------------------------------------------===//
13 
14 #include "AMDGPUInstructionSelector.h"
15 #include "AMDGPUInstrInfo.h"
16 #include "AMDGPUGlobalISelUtils.h"
17 #include "AMDGPURegisterBankInfo.h"
18 #include "AMDGPURegisterInfo.h"
19 #include "AMDGPUSubtarget.h"
20 #include "AMDGPUTargetMachine.h"
21 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
22 #include "SIMachineFunctionInfo.h"
23 #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
24 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
25 #include "llvm/CodeGen/GlobalISel/InstructionSelectorImpl.h"
26 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
27 #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
28 #include "llvm/CodeGen/GlobalISel/Utils.h"
29 #include "llvm/CodeGen/MachineBasicBlock.h"
30 #include "llvm/CodeGen/MachineFunction.h"
31 #include "llvm/CodeGen/MachineInstr.h"
32 #include "llvm/CodeGen/MachineInstrBuilder.h"
33 #include "llvm/CodeGen/MachineRegisterInfo.h"
34 #include "llvm/IR/Type.h"
35 #include "llvm/Support/Debug.h"
36 #include "llvm/Support/raw_ostream.h"
37 
38 #define DEBUG_TYPE "amdgpu-isel"
39 
40 using namespace llvm;
41 using namespace MIPatternMatch;
42 
43 #define GET_GLOBALISEL_IMPL
44 #define AMDGPUSubtarget GCNSubtarget
45 #include "AMDGPUGenGlobalISel.inc"
46 #undef GET_GLOBALISEL_IMPL
47 #undef AMDGPUSubtarget
48 
49 AMDGPUInstructionSelector::AMDGPUInstructionSelector(
50     const GCNSubtarget &STI, const AMDGPURegisterBankInfo &RBI,
51     const AMDGPUTargetMachine &TM)
52     : InstructionSelector(), TII(*STI.getInstrInfo()),
53       TRI(*STI.getRegisterInfo()), RBI(RBI), TM(TM),
54       STI(STI),
55       EnableLateStructurizeCFG(AMDGPUTargetMachine::EnableLateStructurizeCFG),
56 #define GET_GLOBALISEL_PREDICATES_INIT
57 #include "AMDGPUGenGlobalISel.inc"
58 #undef GET_GLOBALISEL_PREDICATES_INIT
59 #define GET_GLOBALISEL_TEMPORARIES_INIT
60 #include "AMDGPUGenGlobalISel.inc"
61 #undef GET_GLOBALISEL_TEMPORARIES_INIT
62 {
63 }
64 
65 const char *AMDGPUInstructionSelector::getName() { return DEBUG_TYPE; }
66 
67 void AMDGPUInstructionSelector::setupMF(MachineFunction &MF, GISelKnownBits &KB,
68                                         CodeGenCoverage &CoverageInfo) {
69   MRI = &MF.getRegInfo();
70   InstructionSelector::setupMF(MF, KB, CoverageInfo);
71 }
72 
73 bool AMDGPUInstructionSelector::isVCC(Register Reg,
74                                       const MachineRegisterInfo &MRI) const {
75   if (Register::isPhysicalRegister(Reg))
76     return Reg == TRI.getVCC();
77 
78   auto &RegClassOrBank = MRI.getRegClassOrRegBank(Reg);
79   const TargetRegisterClass *RC =
80       RegClassOrBank.dyn_cast<const TargetRegisterClass*>();
81   if (RC) {
82     const LLT Ty = MRI.getType(Reg);
83     return RC->hasSuperClassEq(TRI.getBoolRC()) &&
84            Ty.isValid() && Ty.getSizeInBits() == 1;
85   }
86 
87   const RegisterBank *RB = RegClassOrBank.get<const RegisterBank *>();
88   return RB->getID() == AMDGPU::VCCRegBankID;
89 }
90 
91 bool AMDGPUInstructionSelector::constrainCopyLikeIntrin(MachineInstr &MI,
92                                                         unsigned NewOpc) const {
93   MI.setDesc(TII.get(NewOpc));
94   MI.RemoveOperand(1); // Remove intrinsic ID.
95   MI.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
96 
97   MachineOperand &Dst = MI.getOperand(0);
98   MachineOperand &Src = MI.getOperand(1);
99 
100   // TODO: This should be legalized to s32 if needed
101   if (MRI->getType(Dst.getReg()) == LLT::scalar(1))
102     return false;
103 
104   const TargetRegisterClass *DstRC
105     = TRI.getConstrainedRegClassForOperand(Dst, *MRI);
106   const TargetRegisterClass *SrcRC
107     = TRI.getConstrainedRegClassForOperand(Src, *MRI);
108   if (!DstRC || DstRC != SrcRC)
109     return false;
110 
111   return RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI) &&
112          RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI);
113 }
114 
115 bool AMDGPUInstructionSelector::selectCOPY(MachineInstr &I) const {
116   const DebugLoc &DL = I.getDebugLoc();
117   MachineBasicBlock *BB = I.getParent();
118   I.setDesc(TII.get(TargetOpcode::COPY));
119 
120   const MachineOperand &Src = I.getOperand(1);
121   MachineOperand &Dst = I.getOperand(0);
122   Register DstReg = Dst.getReg();
123   Register SrcReg = Src.getReg();
124 
125   if (isVCC(DstReg, *MRI)) {
126     if (SrcReg == AMDGPU::SCC) {
127       const TargetRegisterClass *RC
128         = TRI.getConstrainedRegClassForOperand(Dst, *MRI);
129       if (!RC)
130         return true;
131       return RBI.constrainGenericRegister(DstReg, *RC, *MRI);
132     }
133 
134     if (!isVCC(SrcReg, *MRI)) {
135       // TODO: Should probably leave the copy and let copyPhysReg expand it.
136       if (!RBI.constrainGenericRegister(DstReg, *TRI.getBoolRC(), *MRI))
137         return false;
138 
139       const TargetRegisterClass *SrcRC
140         = TRI.getConstrainedRegClassForOperand(Src, *MRI);
141 
142       Register MaskedReg = MRI->createVirtualRegister(SrcRC);
143 
144       // We can't trust the high bits at this point, so clear them.
145 
146       // TODO: Skip masking high bits if def is known boolean.
147 
148       unsigned AndOpc = TRI.isSGPRClass(SrcRC) ?
149         AMDGPU::S_AND_B32 : AMDGPU::V_AND_B32_e32;
150       BuildMI(*BB, &I, DL, TII.get(AndOpc), MaskedReg)
151         .addImm(1)
152         .addReg(SrcReg);
153       BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_CMP_NE_U32_e64), DstReg)
154         .addImm(0)
155         .addReg(MaskedReg);
156 
157       if (!MRI->getRegClassOrNull(SrcReg))
158         MRI->setRegClass(SrcReg, SrcRC);
159       I.eraseFromParent();
160       return true;
161     }
162 
163     const TargetRegisterClass *RC =
164       TRI.getConstrainedRegClassForOperand(Dst, *MRI);
165     if (RC && !RBI.constrainGenericRegister(DstReg, *RC, *MRI))
166       return false;
167 
168     // Don't constrain the source register to a class so the def instruction
169     // handles it (unless it's undef).
170     //
171     // FIXME: This is a hack. When selecting the def, we neeed to know
172     // specifically know that the result is VCCRegBank, and not just an SGPR
173     // with size 1. An SReg_32 with size 1 is ambiguous with wave32.
174     if (Src.isUndef()) {
175       const TargetRegisterClass *SrcRC =
176         TRI.getConstrainedRegClassForOperand(Src, *MRI);
177       if (SrcRC && !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI))
178         return false;
179     }
180 
181     return true;
182   }
183 
184   for (const MachineOperand &MO : I.operands()) {
185     if (Register::isPhysicalRegister(MO.getReg()))
186       continue;
187 
188     const TargetRegisterClass *RC =
189             TRI.getConstrainedRegClassForOperand(MO, *MRI);
190     if (!RC)
191       continue;
192     RBI.constrainGenericRegister(MO.getReg(), *RC, *MRI);
193   }
194   return true;
195 }
196 
197 bool AMDGPUInstructionSelector::selectPHI(MachineInstr &I) const {
198   const Register DefReg = I.getOperand(0).getReg();
199   const LLT DefTy = MRI->getType(DefReg);
200 
201   // TODO: Verify this doesn't have insane operands (i.e. VGPR to SGPR copy)
202 
203   const RegClassOrRegBank &RegClassOrBank =
204     MRI->getRegClassOrRegBank(DefReg);
205 
206   const TargetRegisterClass *DefRC
207     = RegClassOrBank.dyn_cast<const TargetRegisterClass *>();
208   if (!DefRC) {
209     if (!DefTy.isValid()) {
210       LLVM_DEBUG(dbgs() << "PHI operand has no type, not a gvreg?\n");
211       return false;
212     }
213 
214     const RegisterBank &RB = *RegClassOrBank.get<const RegisterBank *>();
215     DefRC = TRI.getRegClassForTypeOnBank(DefTy, RB, *MRI);
216     if (!DefRC) {
217       LLVM_DEBUG(dbgs() << "PHI operand has unexpected size/bank\n");
218       return false;
219     }
220   }
221 
222   // TODO: Verify that all registers have the same bank
223   I.setDesc(TII.get(TargetOpcode::PHI));
224   return RBI.constrainGenericRegister(DefReg, *DefRC, *MRI);
225 }
226 
227 MachineOperand
228 AMDGPUInstructionSelector::getSubOperand64(MachineOperand &MO,
229                                            const TargetRegisterClass &SubRC,
230                                            unsigned SubIdx) const {
231 
232   MachineInstr *MI = MO.getParent();
233   MachineBasicBlock *BB = MO.getParent()->getParent();
234   Register DstReg = MRI->createVirtualRegister(&SubRC);
235 
236   if (MO.isReg()) {
237     unsigned ComposedSubIdx = TRI.composeSubRegIndices(MO.getSubReg(), SubIdx);
238     Register Reg = MO.getReg();
239     BuildMI(*BB, MI, MI->getDebugLoc(), TII.get(AMDGPU::COPY), DstReg)
240             .addReg(Reg, 0, ComposedSubIdx);
241 
242     return MachineOperand::CreateReg(DstReg, MO.isDef(), MO.isImplicit(),
243                                      MO.isKill(), MO.isDead(), MO.isUndef(),
244                                      MO.isEarlyClobber(), 0, MO.isDebug(),
245                                      MO.isInternalRead());
246   }
247 
248   assert(MO.isImm());
249 
250   APInt Imm(64, MO.getImm());
251 
252   switch (SubIdx) {
253   default:
254     llvm_unreachable("do not know to split immediate with this sub index.");
255   case AMDGPU::sub0:
256     return MachineOperand::CreateImm(Imm.getLoBits(32).getSExtValue());
257   case AMDGPU::sub1:
258     return MachineOperand::CreateImm(Imm.getHiBits(32).getSExtValue());
259   }
260 }
261 
262 static unsigned getLogicalBitOpcode(unsigned Opc, bool Is64) {
263   switch (Opc) {
264   case AMDGPU::G_AND:
265     return Is64 ? AMDGPU::S_AND_B64 : AMDGPU::S_AND_B32;
266   case AMDGPU::G_OR:
267     return Is64 ? AMDGPU::S_OR_B64 : AMDGPU::S_OR_B32;
268   case AMDGPU::G_XOR:
269     return Is64 ? AMDGPU::S_XOR_B64 : AMDGPU::S_XOR_B32;
270   default:
271     llvm_unreachable("not a bit op");
272   }
273 }
274 
275 bool AMDGPUInstructionSelector::selectG_AND_OR_XOR(MachineInstr &I) const {
276   MachineOperand &Dst = I.getOperand(0);
277   MachineOperand &Src0 = I.getOperand(1);
278   MachineOperand &Src1 = I.getOperand(2);
279   Register DstReg = Dst.getReg();
280   unsigned Size = RBI.getSizeInBits(DstReg, *MRI, TRI);
281 
282   const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
283   if (DstRB->getID() == AMDGPU::VCCRegBankID) {
284     const TargetRegisterClass *RC = TRI.getBoolRC();
285     unsigned InstOpc = getLogicalBitOpcode(I.getOpcode(),
286                                            RC == &AMDGPU::SReg_64RegClass);
287     I.setDesc(TII.get(InstOpc));
288 
289     // FIXME: Hack to avoid turning the register bank into a register class.
290     // The selector for G_ICMP relies on seeing the register bank for the result
291     // is VCC. In wave32 if we constrain the registers to SReg_32 here, it will
292     // be ambiguous whether it's a scalar or vector bool.
293     if (Src0.isUndef() && !MRI->getRegClassOrNull(Src0.getReg()))
294       MRI->setRegClass(Src0.getReg(), RC);
295     if (Src1.isUndef() && !MRI->getRegClassOrNull(Src1.getReg()))
296       MRI->setRegClass(Src1.getReg(), RC);
297 
298     return RBI.constrainGenericRegister(DstReg, *RC, *MRI);
299   }
300 
301   // TODO: Should this allow an SCC bank result, and produce a copy from SCC for
302   // the result?
303   if (DstRB->getID() == AMDGPU::SGPRRegBankID) {
304     unsigned InstOpc = getLogicalBitOpcode(I.getOpcode(), Size > 32);
305     I.setDesc(TII.get(InstOpc));
306     // Dead implicit-def of scc
307     I.addOperand(MachineOperand::CreateReg(AMDGPU::SCC, true, // isDef
308                                            true, // isImp
309                                            false, // isKill
310                                            true)); // isDead
311     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
312   }
313 
314   return false;
315 }
316 
317 bool AMDGPUInstructionSelector::selectG_ADD_SUB(MachineInstr &I) const {
318   MachineBasicBlock *BB = I.getParent();
319   MachineFunction *MF = BB->getParent();
320   Register DstReg = I.getOperand(0).getReg();
321   const DebugLoc &DL = I.getDebugLoc();
322   unsigned Size = RBI.getSizeInBits(DstReg, *MRI, TRI);
323   const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
324   const bool IsSALU = DstRB->getID() == AMDGPU::SGPRRegBankID;
325   const bool Sub = I.getOpcode() == TargetOpcode::G_SUB;
326 
327   if (Size == 32) {
328     if (IsSALU) {
329       const unsigned Opc = Sub ? AMDGPU::S_SUB_U32 : AMDGPU::S_ADD_U32;
330       MachineInstr *Add =
331         BuildMI(*BB, &I, DL, TII.get(Opc), DstReg)
332         .add(I.getOperand(1))
333         .add(I.getOperand(2));
334       I.eraseFromParent();
335       return constrainSelectedInstRegOperands(*Add, TII, TRI, RBI);
336     }
337 
338     if (STI.hasAddNoCarry()) {
339       const unsigned Opc = Sub ? AMDGPU::V_SUB_U32_e64 : AMDGPU::V_ADD_U32_e64;
340       I.setDesc(TII.get(Opc));
341       I.addOperand(*MF, MachineOperand::CreateImm(0));
342       I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
343       return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
344     }
345 
346     const unsigned Opc = Sub ? AMDGPU::V_SUB_I32_e64 : AMDGPU::V_ADD_I32_e64;
347 
348     Register UnusedCarry = MRI->createVirtualRegister(TRI.getWaveMaskRegClass());
349     MachineInstr *Add
350       = BuildMI(*BB, &I, DL, TII.get(Opc), DstReg)
351       .addDef(UnusedCarry, RegState::Dead)
352       .add(I.getOperand(1))
353       .add(I.getOperand(2))
354       .addImm(0);
355     I.eraseFromParent();
356     return constrainSelectedInstRegOperands(*Add, TII, TRI, RBI);
357   }
358 
359   assert(!Sub && "illegal sub should not reach here");
360 
361   const TargetRegisterClass &RC
362     = IsSALU ? AMDGPU::SReg_64_XEXECRegClass : AMDGPU::VReg_64RegClass;
363   const TargetRegisterClass &HalfRC
364     = IsSALU ? AMDGPU::SReg_32RegClass : AMDGPU::VGPR_32RegClass;
365 
366   MachineOperand Lo1(getSubOperand64(I.getOperand(1), HalfRC, AMDGPU::sub0));
367   MachineOperand Lo2(getSubOperand64(I.getOperand(2), HalfRC, AMDGPU::sub0));
368   MachineOperand Hi1(getSubOperand64(I.getOperand(1), HalfRC, AMDGPU::sub1));
369   MachineOperand Hi2(getSubOperand64(I.getOperand(2), HalfRC, AMDGPU::sub1));
370 
371   Register DstLo = MRI->createVirtualRegister(&HalfRC);
372   Register DstHi = MRI->createVirtualRegister(&HalfRC);
373 
374   if (IsSALU) {
375     BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_ADD_U32), DstLo)
376       .add(Lo1)
377       .add(Lo2);
378     BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_ADDC_U32), DstHi)
379       .add(Hi1)
380       .add(Hi2);
381   } else {
382     const TargetRegisterClass *CarryRC = TRI.getWaveMaskRegClass();
383     Register CarryReg = MRI->createVirtualRegister(CarryRC);
384     BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_ADD_I32_e64), DstLo)
385       .addDef(CarryReg)
386       .add(Lo1)
387       .add(Lo2)
388       .addImm(0);
389     MachineInstr *Addc = BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_ADDC_U32_e64), DstHi)
390       .addDef(MRI->createVirtualRegister(CarryRC), RegState::Dead)
391       .add(Hi1)
392       .add(Hi2)
393       .addReg(CarryReg, RegState::Kill)
394       .addImm(0);
395 
396     if (!constrainSelectedInstRegOperands(*Addc, TII, TRI, RBI))
397       return false;
398   }
399 
400   BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
401     .addReg(DstLo)
402     .addImm(AMDGPU::sub0)
403     .addReg(DstHi)
404     .addImm(AMDGPU::sub1);
405 
406 
407   if (!RBI.constrainGenericRegister(DstReg, RC, *MRI))
408     return false;
409 
410   I.eraseFromParent();
411   return true;
412 }
413 
414 bool AMDGPUInstructionSelector::selectG_UADDO_USUBO_UADDE_USUBE(
415   MachineInstr &I) const {
416   MachineBasicBlock *BB = I.getParent();
417   MachineFunction *MF = BB->getParent();
418   const DebugLoc &DL = I.getDebugLoc();
419   Register Dst0Reg = I.getOperand(0).getReg();
420   Register Dst1Reg = I.getOperand(1).getReg();
421   const bool IsAdd = I.getOpcode() == AMDGPU::G_UADDO ||
422                      I.getOpcode() == AMDGPU::G_UADDE;
423   const bool HasCarryIn = I.getOpcode() == AMDGPU::G_UADDE ||
424                           I.getOpcode() == AMDGPU::G_USUBE;
425 
426   if (isVCC(Dst1Reg, *MRI)) {
427       // The name of the opcodes are misleading. v_add_i32/v_sub_i32 have unsigned
428       // carry out despite the _i32 name. These were renamed in VI to _U32.
429       // FIXME: We should probably rename the opcodes here.
430     unsigned NoCarryOpc = IsAdd ? AMDGPU::V_ADD_I32_e64 : AMDGPU::V_SUB_I32_e64;
431     unsigned CarryOpc = IsAdd ? AMDGPU::V_ADDC_U32_e64 : AMDGPU::V_SUBB_U32_e64;
432     I.setDesc(TII.get(HasCarryIn ? CarryOpc : NoCarryOpc));
433     I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
434     I.addOperand(*MF, MachineOperand::CreateImm(0));
435     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
436   }
437 
438   Register Src0Reg = I.getOperand(2).getReg();
439   Register Src1Reg = I.getOperand(3).getReg();
440 
441   if (HasCarryIn) {
442     BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::SCC)
443       .addReg(I.getOperand(4).getReg());
444   }
445 
446   unsigned NoCarryOpc = IsAdd ? AMDGPU::S_ADD_U32 : AMDGPU::S_SUB_U32;
447   unsigned CarryOpc = IsAdd ? AMDGPU::S_ADDC_U32 : AMDGPU::S_SUBB_U32;
448 
449   BuildMI(*BB, &I, DL, TII.get(HasCarryIn ? CarryOpc : NoCarryOpc), Dst0Reg)
450     .add(I.getOperand(2))
451     .add(I.getOperand(3));
452   BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), Dst1Reg)
453     .addReg(AMDGPU::SCC);
454 
455   if (!MRI->getRegClassOrNull(Dst1Reg))
456     MRI->setRegClass(Dst1Reg, &AMDGPU::SReg_32RegClass);
457 
458   if (!RBI.constrainGenericRegister(Dst0Reg, AMDGPU::SReg_32RegClass, *MRI) ||
459       !RBI.constrainGenericRegister(Src0Reg, AMDGPU::SReg_32RegClass, *MRI) ||
460       !RBI.constrainGenericRegister(Src1Reg, AMDGPU::SReg_32RegClass, *MRI))
461     return false;
462 
463   if (HasCarryIn &&
464       !RBI.constrainGenericRegister(I.getOperand(4).getReg(),
465                                     AMDGPU::SReg_32RegClass, *MRI))
466     return false;
467 
468   I.eraseFromParent();
469   return true;
470 }
471 
472 bool AMDGPUInstructionSelector::selectG_EXTRACT(MachineInstr &I) const {
473   MachineBasicBlock *BB = I.getParent();
474   Register DstReg = I.getOperand(0).getReg();
475   Register SrcReg = I.getOperand(1).getReg();
476   LLT DstTy = MRI->getType(DstReg);
477   LLT SrcTy = MRI->getType(SrcReg);
478   const unsigned SrcSize = SrcTy.getSizeInBits();
479   const unsigned DstSize = DstTy.getSizeInBits();
480 
481   // TODO: Should handle any multiple of 32 offset.
482   unsigned Offset = I.getOperand(2).getImm();
483   if (Offset % DstSize != 0)
484     return false;
485 
486   const RegisterBank *SrcBank = RBI.getRegBank(SrcReg, *MRI, TRI);
487   const TargetRegisterClass *SrcRC =
488     TRI.getRegClassForSizeOnBank(SrcSize, *SrcBank, *MRI);
489   if (!SrcRC)
490     return false;
491 
492   ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(SrcRC, DstSize / 8);
493 
494   const DebugLoc &DL = I.getDebugLoc();
495   MachineInstr *Copy = BuildMI(*BB, &I, DL, TII.get(TargetOpcode::COPY), DstReg)
496                                .addReg(SrcReg, 0, SubRegs[Offset / DstSize]);
497 
498   for (const MachineOperand &MO : Copy->operands()) {
499     const TargetRegisterClass *RC =
500             TRI.getConstrainedRegClassForOperand(MO, *MRI);
501     if (!RC)
502       continue;
503     RBI.constrainGenericRegister(MO.getReg(), *RC, *MRI);
504   }
505   I.eraseFromParent();
506   return true;
507 }
508 
509 bool AMDGPUInstructionSelector::selectG_MERGE_VALUES(MachineInstr &MI) const {
510   MachineBasicBlock *BB = MI.getParent();
511   Register DstReg = MI.getOperand(0).getReg();
512   LLT DstTy = MRI->getType(DstReg);
513   LLT SrcTy = MRI->getType(MI.getOperand(1).getReg());
514 
515   const unsigned SrcSize = SrcTy.getSizeInBits();
516   if (SrcSize < 32)
517     return selectImpl(MI, *CoverageInfo);
518 
519   const DebugLoc &DL = MI.getDebugLoc();
520   const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
521   const unsigned DstSize = DstTy.getSizeInBits();
522   const TargetRegisterClass *DstRC =
523     TRI.getRegClassForSizeOnBank(DstSize, *DstBank, *MRI);
524   if (!DstRC)
525     return false;
526 
527   ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(DstRC, SrcSize / 8);
528   MachineInstrBuilder MIB =
529     BuildMI(*BB, &MI, DL, TII.get(TargetOpcode::REG_SEQUENCE), DstReg);
530   for (int I = 0, E = MI.getNumOperands() - 1; I != E; ++I) {
531     MachineOperand &Src = MI.getOperand(I + 1);
532     MIB.addReg(Src.getReg(), getUndefRegState(Src.isUndef()));
533     MIB.addImm(SubRegs[I]);
534 
535     const TargetRegisterClass *SrcRC
536       = TRI.getConstrainedRegClassForOperand(Src, *MRI);
537     if (SrcRC && !RBI.constrainGenericRegister(Src.getReg(), *SrcRC, *MRI))
538       return false;
539   }
540 
541   if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI))
542     return false;
543 
544   MI.eraseFromParent();
545   return true;
546 }
547 
548 bool AMDGPUInstructionSelector::selectG_UNMERGE_VALUES(MachineInstr &MI) const {
549   MachineBasicBlock *BB = MI.getParent();
550   const int NumDst = MI.getNumOperands() - 1;
551 
552   MachineOperand &Src = MI.getOperand(NumDst);
553 
554   Register SrcReg = Src.getReg();
555   Register DstReg0 = MI.getOperand(0).getReg();
556   LLT DstTy = MRI->getType(DstReg0);
557   LLT SrcTy = MRI->getType(SrcReg);
558 
559   const unsigned DstSize = DstTy.getSizeInBits();
560   const unsigned SrcSize = SrcTy.getSizeInBits();
561   const DebugLoc &DL = MI.getDebugLoc();
562   const RegisterBank *SrcBank = RBI.getRegBank(SrcReg, *MRI, TRI);
563 
564   const TargetRegisterClass *SrcRC =
565     TRI.getRegClassForSizeOnBank(SrcSize, *SrcBank, *MRI);
566   if (!SrcRC || !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI))
567     return false;
568 
569   const unsigned SrcFlags = getUndefRegState(Src.isUndef());
570 
571   // Note we could have mixed SGPR and VGPR destination banks for an SGPR
572   // source, and this relies on the fact that the same subregister indices are
573   // used for both.
574   ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(SrcRC, DstSize / 8);
575   for (int I = 0, E = NumDst; I != E; ++I) {
576     MachineOperand &Dst = MI.getOperand(I);
577     BuildMI(*BB, &MI, DL, TII.get(TargetOpcode::COPY), Dst.getReg())
578       .addReg(SrcReg, SrcFlags, SubRegs[I]);
579 
580     const TargetRegisterClass *DstRC =
581       TRI.getConstrainedRegClassForOperand(Dst, *MRI);
582     if (DstRC && !RBI.constrainGenericRegister(Dst.getReg(), *DstRC, *MRI))
583       return false;
584   }
585 
586   MI.eraseFromParent();
587   return true;
588 }
589 
590 bool AMDGPUInstructionSelector::selectG_PTR_ADD(MachineInstr &I) const {
591   return selectG_ADD_SUB(I);
592 }
593 
594 bool AMDGPUInstructionSelector::selectG_IMPLICIT_DEF(MachineInstr &I) const {
595   const MachineOperand &MO = I.getOperand(0);
596 
597   // FIXME: Interface for getConstrainedRegClassForOperand needs work. The
598   // regbank check here is to know why getConstrainedRegClassForOperand failed.
599   const TargetRegisterClass *RC = TRI.getConstrainedRegClassForOperand(MO, *MRI);
600   if ((!RC && !MRI->getRegBankOrNull(MO.getReg())) ||
601       (RC && RBI.constrainGenericRegister(MO.getReg(), *RC, *MRI))) {
602     I.setDesc(TII.get(TargetOpcode::IMPLICIT_DEF));
603     return true;
604   }
605 
606   return false;
607 }
608 
609 bool AMDGPUInstructionSelector::selectG_INSERT(MachineInstr &I) const {
610   MachineBasicBlock *BB = I.getParent();
611 
612   Register DstReg = I.getOperand(0).getReg();
613   Register Src0Reg = I.getOperand(1).getReg();
614   Register Src1Reg = I.getOperand(2).getReg();
615   LLT Src1Ty = MRI->getType(Src1Reg);
616 
617   unsigned DstSize = MRI->getType(DstReg).getSizeInBits();
618   unsigned InsSize = Src1Ty.getSizeInBits();
619 
620   int64_t Offset = I.getOperand(3).getImm();
621   if (Offset % 32 != 0)
622     return false;
623 
624   unsigned SubReg = TRI.getSubRegFromChannel(Offset / 32, InsSize / 32);
625   if (SubReg == AMDGPU::NoSubRegister)
626     return false;
627 
628   const RegisterBank *DstBank = RBI.getRegBank(DstReg, *MRI, TRI);
629   const TargetRegisterClass *DstRC =
630     TRI.getRegClassForSizeOnBank(DstSize, *DstBank, *MRI);
631   if (!DstRC)
632     return false;
633 
634   const RegisterBank *Src0Bank = RBI.getRegBank(Src0Reg, *MRI, TRI);
635   const RegisterBank *Src1Bank = RBI.getRegBank(Src1Reg, *MRI, TRI);
636   const TargetRegisterClass *Src0RC =
637     TRI.getRegClassForSizeOnBank(DstSize, *Src0Bank, *MRI);
638   const TargetRegisterClass *Src1RC =
639     TRI.getRegClassForSizeOnBank(InsSize, *Src1Bank, *MRI);
640 
641   // Deal with weird cases where the class only partially supports the subreg
642   // index.
643   Src0RC = TRI.getSubClassWithSubReg(Src0RC, SubReg);
644   if (!Src0RC)
645     return false;
646 
647   if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
648       !RBI.constrainGenericRegister(Src0Reg, *Src0RC, *MRI) ||
649       !RBI.constrainGenericRegister(Src1Reg, *Src1RC, *MRI))
650     return false;
651 
652   const DebugLoc &DL = I.getDebugLoc();
653   BuildMI(*BB, &I, DL, TII.get(TargetOpcode::INSERT_SUBREG), DstReg)
654     .addReg(Src0Reg)
655     .addReg(Src1Reg)
656     .addImm(SubReg);
657 
658   I.eraseFromParent();
659   return true;
660 }
661 
662 bool AMDGPUInstructionSelector::selectInterpP1F16(MachineInstr &MI) const {
663   if (STI.getLDSBankCount() != 16)
664     return selectImpl(MI, *CoverageInfo);
665 
666   Register Dst = MI.getOperand(0).getReg();
667   Register Src0 = MI.getOperand(2).getReg();
668   Register M0Val = MI.getOperand(6).getReg();
669   if (!RBI.constrainGenericRegister(M0Val, AMDGPU::SReg_32RegClass, *MRI) ||
670       !RBI.constrainGenericRegister(Dst, AMDGPU::VGPR_32RegClass, *MRI) ||
671       !RBI.constrainGenericRegister(Src0, AMDGPU::VGPR_32RegClass, *MRI))
672     return false;
673 
674   // This requires 2 instructions. It is possible to write a pattern to support
675   // this, but the generated isel emitter doesn't correctly deal with multiple
676   // output instructions using the same physical register input. The copy to m0
677   // is incorrectly placed before the second instruction.
678   //
679   // TODO: Match source modifiers.
680 
681   Register InterpMov = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
682   const DebugLoc &DL = MI.getDebugLoc();
683   MachineBasicBlock *MBB = MI.getParent();
684 
685   BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
686     .addReg(M0Val);
687   BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_INTERP_MOV_F32), InterpMov)
688     .addImm(2)
689     .addImm(MI.getOperand(4).getImm())  // $attr
690     .addImm(MI.getOperand(3).getImm()); // $attrchan
691 
692   BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::V_INTERP_P1LV_F16), Dst)
693     .addImm(0)                          // $src0_modifiers
694     .addReg(Src0)                       // $src0
695     .addImm(MI.getOperand(4).getImm())  // $attr
696     .addImm(MI.getOperand(3).getImm())  // $attrchan
697     .addImm(0)                          // $src2_modifiers
698     .addReg(InterpMov)                  // $src2 - 2 f16 values selected by high
699     .addImm(MI.getOperand(5).getImm())  // $high
700     .addImm(0)                          // $clamp
701     .addImm(0);                         // $omod
702 
703   MI.eraseFromParent();
704   return true;
705 }
706 
707 bool AMDGPUInstructionSelector::selectG_INTRINSIC(MachineInstr &I) const {
708   unsigned IntrinsicID = I.getIntrinsicID();
709   switch (IntrinsicID) {
710   case Intrinsic::amdgcn_if_break: {
711     MachineBasicBlock *BB = I.getParent();
712 
713     // FIXME: Manually selecting to avoid dealiing with the SReg_1 trick
714     // SelectionDAG uses for wave32 vs wave64.
715     BuildMI(*BB, &I, I.getDebugLoc(), TII.get(AMDGPU::SI_IF_BREAK))
716       .add(I.getOperand(0))
717       .add(I.getOperand(2))
718       .add(I.getOperand(3));
719 
720     Register DstReg = I.getOperand(0).getReg();
721     Register Src0Reg = I.getOperand(2).getReg();
722     Register Src1Reg = I.getOperand(3).getReg();
723 
724     I.eraseFromParent();
725 
726     for (Register Reg : { DstReg, Src0Reg, Src1Reg })
727       MRI->setRegClass(Reg, TRI.getWaveMaskRegClass());
728 
729     return true;
730   }
731   case Intrinsic::amdgcn_interp_p1_f16:
732     return selectInterpP1F16(I);
733   case Intrinsic::amdgcn_wqm:
734     return constrainCopyLikeIntrin(I, AMDGPU::WQM);
735   case Intrinsic::amdgcn_softwqm:
736     return constrainCopyLikeIntrin(I, AMDGPU::SOFT_WQM);
737   case Intrinsic::amdgcn_wwm:
738     return constrainCopyLikeIntrin(I, AMDGPU::WWM);
739   default:
740     return selectImpl(I, *CoverageInfo);
741   }
742 }
743 
744 static int getV_CMPOpcode(CmpInst::Predicate P, unsigned Size) {
745   if (Size != 32 && Size != 64)
746     return -1;
747   switch (P) {
748   default:
749     llvm_unreachable("Unknown condition code!");
750   case CmpInst::ICMP_NE:
751     return Size == 32 ? AMDGPU::V_CMP_NE_U32_e64 : AMDGPU::V_CMP_NE_U64_e64;
752   case CmpInst::ICMP_EQ:
753     return Size == 32 ? AMDGPU::V_CMP_EQ_U32_e64 : AMDGPU::V_CMP_EQ_U64_e64;
754   case CmpInst::ICMP_SGT:
755     return Size == 32 ? AMDGPU::V_CMP_GT_I32_e64 : AMDGPU::V_CMP_GT_I64_e64;
756   case CmpInst::ICMP_SGE:
757     return Size == 32 ? AMDGPU::V_CMP_GE_I32_e64 : AMDGPU::V_CMP_GE_I64_e64;
758   case CmpInst::ICMP_SLT:
759     return Size == 32 ? AMDGPU::V_CMP_LT_I32_e64 : AMDGPU::V_CMP_LT_I64_e64;
760   case CmpInst::ICMP_SLE:
761     return Size == 32 ? AMDGPU::V_CMP_LE_I32_e64 : AMDGPU::V_CMP_LE_I64_e64;
762   case CmpInst::ICMP_UGT:
763     return Size == 32 ? AMDGPU::V_CMP_GT_U32_e64 : AMDGPU::V_CMP_GT_U64_e64;
764   case CmpInst::ICMP_UGE:
765     return Size == 32 ? AMDGPU::V_CMP_GE_U32_e64 : AMDGPU::V_CMP_GE_U64_e64;
766   case CmpInst::ICMP_ULT:
767     return Size == 32 ? AMDGPU::V_CMP_LT_U32_e64 : AMDGPU::V_CMP_LT_U64_e64;
768   case CmpInst::ICMP_ULE:
769     return Size == 32 ? AMDGPU::V_CMP_LE_U32_e64 : AMDGPU::V_CMP_LE_U64_e64;
770   }
771 }
772 
773 int AMDGPUInstructionSelector::getS_CMPOpcode(CmpInst::Predicate P,
774                                               unsigned Size) const {
775   if (Size == 64) {
776     if (!STI.hasScalarCompareEq64())
777       return -1;
778 
779     switch (P) {
780     case CmpInst::ICMP_NE:
781       return AMDGPU::S_CMP_LG_U64;
782     case CmpInst::ICMP_EQ:
783       return AMDGPU::S_CMP_EQ_U64;
784     default:
785       return -1;
786     }
787   }
788 
789   if (Size != 32)
790     return -1;
791 
792   switch (P) {
793   case CmpInst::ICMP_NE:
794     return AMDGPU::S_CMP_LG_U32;
795   case CmpInst::ICMP_EQ:
796     return AMDGPU::S_CMP_EQ_U32;
797   case CmpInst::ICMP_SGT:
798     return AMDGPU::S_CMP_GT_I32;
799   case CmpInst::ICMP_SGE:
800     return AMDGPU::S_CMP_GE_I32;
801   case CmpInst::ICMP_SLT:
802     return AMDGPU::S_CMP_LT_I32;
803   case CmpInst::ICMP_SLE:
804     return AMDGPU::S_CMP_LE_I32;
805   case CmpInst::ICMP_UGT:
806     return AMDGPU::S_CMP_GT_U32;
807   case CmpInst::ICMP_UGE:
808     return AMDGPU::S_CMP_GE_U32;
809   case CmpInst::ICMP_ULT:
810     return AMDGPU::S_CMP_LT_U32;
811   case CmpInst::ICMP_ULE:
812     return AMDGPU::S_CMP_LE_U32;
813   default:
814     llvm_unreachable("Unknown condition code!");
815   }
816 }
817 
818 bool AMDGPUInstructionSelector::selectG_ICMP(MachineInstr &I) const {
819   MachineBasicBlock *BB = I.getParent();
820   const DebugLoc &DL = I.getDebugLoc();
821 
822   Register SrcReg = I.getOperand(2).getReg();
823   unsigned Size = RBI.getSizeInBits(SrcReg, *MRI, TRI);
824 
825   auto Pred = (CmpInst::Predicate)I.getOperand(1).getPredicate();
826 
827   Register CCReg = I.getOperand(0).getReg();
828   if (!isVCC(CCReg, *MRI)) {
829     int Opcode = getS_CMPOpcode(Pred, Size);
830     if (Opcode == -1)
831       return false;
832     MachineInstr *ICmp = BuildMI(*BB, &I, DL, TII.get(Opcode))
833             .add(I.getOperand(2))
834             .add(I.getOperand(3));
835     BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), CCReg)
836       .addReg(AMDGPU::SCC);
837     bool Ret =
838         constrainSelectedInstRegOperands(*ICmp, TII, TRI, RBI) &&
839         RBI.constrainGenericRegister(CCReg, AMDGPU::SReg_32RegClass, *MRI);
840     I.eraseFromParent();
841     return Ret;
842   }
843 
844   int Opcode = getV_CMPOpcode(Pred, Size);
845   if (Opcode == -1)
846     return false;
847 
848   MachineInstr *ICmp = BuildMI(*BB, &I, DL, TII.get(Opcode),
849             I.getOperand(0).getReg())
850             .add(I.getOperand(2))
851             .add(I.getOperand(3));
852   RBI.constrainGenericRegister(ICmp->getOperand(0).getReg(),
853                                *TRI.getBoolRC(), *MRI);
854   bool Ret = constrainSelectedInstRegOperands(*ICmp, TII, TRI, RBI);
855   I.eraseFromParent();
856   return Ret;
857 }
858 
859 bool AMDGPUInstructionSelector::selectEndCfIntrinsic(MachineInstr &MI) const {
860   // FIXME: Manually selecting to avoid dealiing with the SReg_1 trick
861   // SelectionDAG uses for wave32 vs wave64.
862   MachineBasicBlock *BB = MI.getParent();
863   BuildMI(*BB, &MI, MI.getDebugLoc(), TII.get(AMDGPU::SI_END_CF))
864       .add(MI.getOperand(1));
865 
866   Register Reg = MI.getOperand(1).getReg();
867   MI.eraseFromParent();
868 
869   if (!MRI->getRegClassOrNull(Reg))
870     MRI->setRegClass(Reg, TRI.getWaveMaskRegClass());
871   return true;
872 }
873 
874 static unsigned getDSShaderTypeValue(const MachineFunction &MF) {
875   switch (MF.getFunction().getCallingConv()) {
876   case CallingConv::AMDGPU_PS:
877     return 1;
878   case CallingConv::AMDGPU_VS:
879     return 2;
880   case CallingConv::AMDGPU_GS:
881     return 3;
882   case CallingConv::AMDGPU_HS:
883   case CallingConv::AMDGPU_LS:
884   case CallingConv::AMDGPU_ES:
885     report_fatal_error("ds_ordered_count unsupported for this calling conv");
886   case CallingConv::AMDGPU_CS:
887   case CallingConv::AMDGPU_KERNEL:
888   case CallingConv::C:
889   case CallingConv::Fast:
890   default:
891     // Assume other calling conventions are various compute callable functions
892     return 0;
893   }
894 }
895 
896 bool AMDGPUInstructionSelector::selectDSOrderedIntrinsic(
897   MachineInstr &MI, Intrinsic::ID IntrID) const {
898   MachineBasicBlock *MBB = MI.getParent();
899   MachineFunction *MF = MBB->getParent();
900   const DebugLoc &DL = MI.getDebugLoc();
901 
902   unsigned IndexOperand = MI.getOperand(7).getImm();
903   bool WaveRelease = MI.getOperand(8).getImm() != 0;
904   bool WaveDone = MI.getOperand(9).getImm() != 0;
905 
906   if (WaveDone && !WaveRelease)
907     report_fatal_error("ds_ordered_count: wave_done requires wave_release");
908 
909   unsigned OrderedCountIndex = IndexOperand & 0x3f;
910   IndexOperand &= ~0x3f;
911   unsigned CountDw = 0;
912 
913   if (STI.getGeneration() >= AMDGPUSubtarget::GFX10) {
914     CountDw = (IndexOperand >> 24) & 0xf;
915     IndexOperand &= ~(0xf << 24);
916 
917     if (CountDw < 1 || CountDw > 4) {
918       report_fatal_error(
919         "ds_ordered_count: dword count must be between 1 and 4");
920     }
921   }
922 
923   if (IndexOperand)
924     report_fatal_error("ds_ordered_count: bad index operand");
925 
926   unsigned Instruction = IntrID == Intrinsic::amdgcn_ds_ordered_add ? 0 : 1;
927   unsigned ShaderType = getDSShaderTypeValue(*MF);
928 
929   unsigned Offset0 = OrderedCountIndex << 2;
930   unsigned Offset1 = WaveRelease | (WaveDone << 1) | (ShaderType << 2) |
931                      (Instruction << 4);
932 
933   if (STI.getGeneration() >= AMDGPUSubtarget::GFX10)
934     Offset1 |= (CountDw - 1) << 6;
935 
936   unsigned Offset = Offset0 | (Offset1 << 8);
937 
938   Register M0Val = MI.getOperand(2).getReg();
939   BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
940     .addReg(M0Val);
941 
942   Register DstReg = MI.getOperand(0).getReg();
943   Register ValReg = MI.getOperand(3).getReg();
944   MachineInstrBuilder DS =
945     BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::DS_ORDERED_COUNT), DstReg)
946       .addReg(ValReg)
947       .addImm(Offset)
948       .cloneMemRefs(MI);
949 
950   if (!RBI.constrainGenericRegister(M0Val, AMDGPU::SReg_32RegClass, *MRI))
951     return false;
952 
953   bool Ret = constrainSelectedInstRegOperands(*DS, TII, TRI, RBI);
954   MI.eraseFromParent();
955   return Ret;
956 }
957 
958 static unsigned gwsIntrinToOpcode(unsigned IntrID) {
959   switch (IntrID) {
960   case Intrinsic::amdgcn_ds_gws_init:
961     return AMDGPU::DS_GWS_INIT;
962   case Intrinsic::amdgcn_ds_gws_barrier:
963     return AMDGPU::DS_GWS_BARRIER;
964   case Intrinsic::amdgcn_ds_gws_sema_v:
965     return AMDGPU::DS_GWS_SEMA_V;
966   case Intrinsic::amdgcn_ds_gws_sema_br:
967     return AMDGPU::DS_GWS_SEMA_BR;
968   case Intrinsic::amdgcn_ds_gws_sema_p:
969     return AMDGPU::DS_GWS_SEMA_P;
970   case Intrinsic::amdgcn_ds_gws_sema_release_all:
971     return AMDGPU::DS_GWS_SEMA_RELEASE_ALL;
972   default:
973     llvm_unreachable("not a gws intrinsic");
974   }
975 }
976 
977 bool AMDGPUInstructionSelector::selectDSGWSIntrinsic(MachineInstr &MI,
978                                                      Intrinsic::ID IID) const {
979   if (IID == Intrinsic::amdgcn_ds_gws_sema_release_all &&
980       !STI.hasGWSSemaReleaseAll())
981     return false;
982 
983   // intrinsic ID, vsrc, offset
984   const bool HasVSrc = MI.getNumOperands() == 3;
985   assert(HasVSrc || MI.getNumOperands() == 2);
986 
987   Register BaseOffset = MI.getOperand(HasVSrc ? 2 : 1).getReg();
988   const RegisterBank *OffsetRB = RBI.getRegBank(BaseOffset, *MRI, TRI);
989   if (OffsetRB->getID() != AMDGPU::SGPRRegBankID)
990     return false;
991 
992   MachineInstr *OffsetDef = getDefIgnoringCopies(BaseOffset, *MRI);
993   assert(OffsetDef);
994 
995   unsigned ImmOffset;
996 
997   MachineBasicBlock *MBB = MI.getParent();
998   const DebugLoc &DL = MI.getDebugLoc();
999 
1000   MachineInstr *Readfirstlane = nullptr;
1001 
1002   // If we legalized the VGPR input, strip out the readfirstlane to analyze the
1003   // incoming offset, in case there's an add of a constant. We'll have to put it
1004   // back later.
1005   if (OffsetDef->getOpcode() == AMDGPU::V_READFIRSTLANE_B32) {
1006     Readfirstlane = OffsetDef;
1007     BaseOffset = OffsetDef->getOperand(1).getReg();
1008     OffsetDef = getDefIgnoringCopies(BaseOffset, *MRI);
1009   }
1010 
1011   if (OffsetDef->getOpcode() == AMDGPU::G_CONSTANT) {
1012     // If we have a constant offset, try to use the 0 in m0 as the base.
1013     // TODO: Look into changing the default m0 initialization value. If the
1014     // default -1 only set the low 16-bits, we could leave it as-is and add 1 to
1015     // the immediate offset.
1016 
1017     ImmOffset = OffsetDef->getOperand(1).getCImm()->getZExtValue();
1018     BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), AMDGPU::M0)
1019       .addImm(0);
1020   } else {
1021     std::tie(BaseOffset, ImmOffset, OffsetDef)
1022       = AMDGPU::getBaseWithConstantOffset(*MRI, BaseOffset);
1023 
1024     if (Readfirstlane) {
1025       // We have the constant offset now, so put the readfirstlane back on the
1026       // variable component.
1027       if (!RBI.constrainGenericRegister(BaseOffset, AMDGPU::VGPR_32RegClass, *MRI))
1028         return false;
1029 
1030       Readfirstlane->getOperand(1).setReg(BaseOffset);
1031       BaseOffset = Readfirstlane->getOperand(0).getReg();
1032     } else {
1033       if (!RBI.constrainGenericRegister(BaseOffset,
1034                                         AMDGPU::SReg_32RegClass, *MRI))
1035         return false;
1036     }
1037 
1038     Register M0Base = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1039     BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::S_LSHL_B32), M0Base)
1040       .addReg(BaseOffset)
1041       .addImm(16);
1042 
1043     BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
1044       .addReg(M0Base);
1045   }
1046 
1047   // The resource id offset is computed as (<isa opaque base> + M0[21:16] +
1048   // offset field) % 64. Some versions of the programming guide omit the m0
1049   // part, or claim it's from offset 0.
1050   auto MIB = BuildMI(*MBB, &MI, DL, TII.get(gwsIntrinToOpcode(IID)));
1051 
1052   if (HasVSrc) {
1053     Register VSrc = MI.getOperand(1).getReg();
1054     MIB.addReg(VSrc);
1055     if (!RBI.constrainGenericRegister(VSrc, AMDGPU::VGPR_32RegClass, *MRI))
1056       return false;
1057   }
1058 
1059   MIB.addImm(ImmOffset)
1060      .addImm(-1) // $gds
1061      .cloneMemRefs(MI);
1062 
1063   MI.eraseFromParent();
1064   return true;
1065 }
1066 
1067 bool AMDGPUInstructionSelector::selectDSAppendConsume(MachineInstr &MI,
1068                                                       bool IsAppend) const {
1069   Register PtrBase = MI.getOperand(2).getReg();
1070   LLT PtrTy = MRI->getType(PtrBase);
1071   bool IsGDS = PtrTy.getAddressSpace() == AMDGPUAS::REGION_ADDRESS;
1072 
1073   unsigned Offset;
1074   std::tie(PtrBase, Offset) = selectDS1Addr1OffsetImpl(MI.getOperand(2));
1075 
1076   // TODO: Should this try to look through readfirstlane like GWS?
1077   if (!isDSOffsetLegal(PtrBase, Offset, 16)) {
1078     PtrBase = MI.getOperand(2).getReg();
1079     Offset = 0;
1080   }
1081 
1082   MachineBasicBlock *MBB = MI.getParent();
1083   const DebugLoc &DL = MI.getDebugLoc();
1084   const unsigned Opc = IsAppend ? AMDGPU::DS_APPEND : AMDGPU::DS_CONSUME;
1085 
1086   BuildMI(*MBB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
1087     .addReg(PtrBase);
1088   BuildMI(*MBB, &MI, DL, TII.get(Opc), MI.getOperand(0).getReg())
1089     .addImm(Offset)
1090     .addImm(IsGDS ? -1 : 0)
1091     .cloneMemRefs(MI);
1092 
1093   MI.eraseFromParent();
1094   return true;
1095 }
1096 
1097 bool AMDGPUInstructionSelector::selectG_INTRINSIC_W_SIDE_EFFECTS(
1098     MachineInstr &I) const {
1099   unsigned IntrinsicID = I.getIntrinsicID();
1100   switch (IntrinsicID) {
1101   case Intrinsic::amdgcn_end_cf:
1102     return selectEndCfIntrinsic(I);
1103   case Intrinsic::amdgcn_ds_ordered_add:
1104   case Intrinsic::amdgcn_ds_ordered_swap:
1105     return selectDSOrderedIntrinsic(I, IntrinsicID);
1106   case Intrinsic::amdgcn_ds_gws_init:
1107   case Intrinsic::amdgcn_ds_gws_barrier:
1108   case Intrinsic::amdgcn_ds_gws_sema_v:
1109   case Intrinsic::amdgcn_ds_gws_sema_br:
1110   case Intrinsic::amdgcn_ds_gws_sema_p:
1111   case Intrinsic::amdgcn_ds_gws_sema_release_all:
1112     return selectDSGWSIntrinsic(I, IntrinsicID);
1113   case Intrinsic::amdgcn_ds_append:
1114     return selectDSAppendConsume(I, true);
1115   case Intrinsic::amdgcn_ds_consume:
1116     return selectDSAppendConsume(I, false);
1117   default:
1118     return selectImpl(I, *CoverageInfo);
1119   }
1120 }
1121 
1122 bool AMDGPUInstructionSelector::selectG_SELECT(MachineInstr &I) const {
1123   if (selectImpl(I, *CoverageInfo))
1124     return true;
1125 
1126   MachineBasicBlock *BB = I.getParent();
1127   const DebugLoc &DL = I.getDebugLoc();
1128 
1129   Register DstReg = I.getOperand(0).getReg();
1130   unsigned Size = RBI.getSizeInBits(DstReg, *MRI, TRI);
1131   assert(Size <= 32 || Size == 64);
1132   const MachineOperand &CCOp = I.getOperand(1);
1133   Register CCReg = CCOp.getReg();
1134   if (!isVCC(CCReg, *MRI)) {
1135     unsigned SelectOpcode = Size == 64 ? AMDGPU::S_CSELECT_B64 :
1136                                          AMDGPU::S_CSELECT_B32;
1137     MachineInstr *CopySCC = BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), AMDGPU::SCC)
1138             .addReg(CCReg);
1139 
1140     // The generic constrainSelectedInstRegOperands doesn't work for the scc register
1141     // bank, because it does not cover the register class that we used to represent
1142     // for it.  So we need to manually set the register class here.
1143     if (!MRI->getRegClassOrNull(CCReg))
1144         MRI->setRegClass(CCReg, TRI.getConstrainedRegClassForOperand(CCOp, *MRI));
1145     MachineInstr *Select = BuildMI(*BB, &I, DL, TII.get(SelectOpcode), DstReg)
1146             .add(I.getOperand(2))
1147             .add(I.getOperand(3));
1148 
1149     bool Ret = constrainSelectedInstRegOperands(*Select, TII, TRI, RBI) |
1150                constrainSelectedInstRegOperands(*CopySCC, TII, TRI, RBI);
1151     I.eraseFromParent();
1152     return Ret;
1153   }
1154 
1155   // Wide VGPR select should have been split in RegBankSelect.
1156   if (Size > 32)
1157     return false;
1158 
1159   MachineInstr *Select =
1160       BuildMI(*BB, &I, DL, TII.get(AMDGPU::V_CNDMASK_B32_e64), DstReg)
1161               .addImm(0)
1162               .add(I.getOperand(3))
1163               .addImm(0)
1164               .add(I.getOperand(2))
1165               .add(I.getOperand(1));
1166 
1167   bool Ret = constrainSelectedInstRegOperands(*Select, TII, TRI, RBI);
1168   I.eraseFromParent();
1169   return Ret;
1170 }
1171 
1172 bool AMDGPUInstructionSelector::selectG_STORE(MachineInstr &I) const {
1173   initM0(I);
1174   return selectImpl(I, *CoverageInfo);
1175 }
1176 
1177 static int sizeToSubRegIndex(unsigned Size) {
1178   switch (Size) {
1179   case 32:
1180     return AMDGPU::sub0;
1181   case 64:
1182     return AMDGPU::sub0_sub1;
1183   case 96:
1184     return AMDGPU::sub0_sub1_sub2;
1185   case 128:
1186     return AMDGPU::sub0_sub1_sub2_sub3;
1187   case 256:
1188     return AMDGPU::sub0_sub1_sub2_sub3_sub4_sub5_sub6_sub7;
1189   default:
1190     if (Size < 32)
1191       return AMDGPU::sub0;
1192     if (Size > 256)
1193       return -1;
1194     return sizeToSubRegIndex(PowerOf2Ceil(Size));
1195   }
1196 }
1197 
1198 bool AMDGPUInstructionSelector::selectG_TRUNC(MachineInstr &I) const {
1199   Register DstReg = I.getOperand(0).getReg();
1200   Register SrcReg = I.getOperand(1).getReg();
1201   const LLT DstTy = MRI->getType(DstReg);
1202   const LLT SrcTy = MRI->getType(SrcReg);
1203   if (!DstTy.isScalar())
1204     return false;
1205 
1206   const LLT S1 = LLT::scalar(1);
1207 
1208   const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
1209   const RegisterBank *DstRB;
1210   if (DstTy == S1) {
1211     // This is a special case. We don't treat s1 for legalization artifacts as
1212     // vcc booleans.
1213     DstRB = SrcRB;
1214   } else {
1215     DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
1216     if (SrcRB != DstRB)
1217       return false;
1218   }
1219 
1220   unsigned DstSize = DstTy.getSizeInBits();
1221   unsigned SrcSize = SrcTy.getSizeInBits();
1222 
1223   const TargetRegisterClass *SrcRC
1224     = TRI.getRegClassForSizeOnBank(SrcSize, *SrcRB, *MRI);
1225   const TargetRegisterClass *DstRC
1226     = TRI.getRegClassForSizeOnBank(DstSize, *DstRB, *MRI);
1227 
1228   if (SrcSize > 32) {
1229     int SubRegIdx = sizeToSubRegIndex(DstSize);
1230     if (SubRegIdx == -1)
1231       return false;
1232 
1233     // Deal with weird cases where the class only partially supports the subreg
1234     // index.
1235     SrcRC = TRI.getSubClassWithSubReg(SrcRC, SubRegIdx);
1236     if (!SrcRC)
1237       return false;
1238 
1239     I.getOperand(1).setSubReg(SubRegIdx);
1240   }
1241 
1242   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI) ||
1243       !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI)) {
1244     LLVM_DEBUG(dbgs() << "Failed to constrain G_TRUNC\n");
1245     return false;
1246   }
1247 
1248   I.setDesc(TII.get(TargetOpcode::COPY));
1249   return true;
1250 }
1251 
1252 /// \returns true if a bitmask for \p Size bits will be an inline immediate.
1253 static bool shouldUseAndMask(unsigned Size, unsigned &Mask) {
1254   Mask = maskTrailingOnes<unsigned>(Size);
1255   int SignedMask = static_cast<int>(Mask);
1256   return SignedMask >= -16 && SignedMask <= 64;
1257 }
1258 
1259 // Like RegisterBankInfo::getRegBank, but don't assume vcc for s1.
1260 const RegisterBank *AMDGPUInstructionSelector::getArtifactRegBank(
1261   Register Reg, const MachineRegisterInfo &MRI,
1262   const TargetRegisterInfo &TRI) const {
1263   const RegClassOrRegBank &RegClassOrBank = MRI.getRegClassOrRegBank(Reg);
1264   if (auto *RB = RegClassOrBank.dyn_cast<const RegisterBank *>())
1265     return RB;
1266 
1267   // Ignore the type, since we don't use vcc in artifacts.
1268   if (auto *RC = RegClassOrBank.dyn_cast<const TargetRegisterClass *>())
1269     return &RBI.getRegBankFromRegClass(*RC, LLT());
1270   return nullptr;
1271 }
1272 
1273 bool AMDGPUInstructionSelector::selectG_SZA_EXT(MachineInstr &I) const {
1274   bool Signed = I.getOpcode() == AMDGPU::G_SEXT;
1275   const DebugLoc &DL = I.getDebugLoc();
1276   MachineBasicBlock &MBB = *I.getParent();
1277   const Register DstReg = I.getOperand(0).getReg();
1278   const Register SrcReg = I.getOperand(1).getReg();
1279 
1280   const LLT DstTy = MRI->getType(DstReg);
1281   const LLT SrcTy = MRI->getType(SrcReg);
1282   const unsigned SrcSize = SrcTy.getSizeInBits();
1283   const unsigned DstSize = DstTy.getSizeInBits();
1284   if (!DstTy.isScalar())
1285     return false;
1286 
1287   if (I.getOpcode() == AMDGPU::G_ANYEXT)
1288     return selectCOPY(I);
1289 
1290   // Artifact casts should never use vcc.
1291   const RegisterBank *SrcBank = getArtifactRegBank(SrcReg, *MRI, TRI);
1292 
1293   if (SrcBank->getID() == AMDGPU::VGPRRegBankID && DstSize <= 32) {
1294     // 64-bit should have been split up in RegBankSelect
1295 
1296     // Try to use an and with a mask if it will save code size.
1297     unsigned Mask;
1298     if (!Signed && shouldUseAndMask(SrcSize, Mask)) {
1299       MachineInstr *ExtI =
1300       BuildMI(MBB, I, DL, TII.get(AMDGPU::V_AND_B32_e32), DstReg)
1301         .addImm(Mask)
1302         .addReg(SrcReg);
1303       I.eraseFromParent();
1304       return constrainSelectedInstRegOperands(*ExtI, TII, TRI, RBI);
1305     }
1306 
1307     const unsigned BFE = Signed ? AMDGPU::V_BFE_I32 : AMDGPU::V_BFE_U32;
1308     MachineInstr *ExtI =
1309       BuildMI(MBB, I, DL, TII.get(BFE), DstReg)
1310       .addReg(SrcReg)
1311       .addImm(0) // Offset
1312       .addImm(SrcSize); // Width
1313     I.eraseFromParent();
1314     return constrainSelectedInstRegOperands(*ExtI, TII, TRI, RBI);
1315   }
1316 
1317   if (SrcBank->getID() == AMDGPU::SGPRRegBankID && DstSize <= 64) {
1318     if (!RBI.constrainGenericRegister(SrcReg, AMDGPU::SReg_32RegClass, *MRI))
1319       return false;
1320 
1321     if (Signed && DstSize == 32 && (SrcSize == 8 || SrcSize == 16)) {
1322       const unsigned SextOpc = SrcSize == 8 ?
1323         AMDGPU::S_SEXT_I32_I8 : AMDGPU::S_SEXT_I32_I16;
1324       BuildMI(MBB, I, DL, TII.get(SextOpc), DstReg)
1325         .addReg(SrcReg);
1326       I.eraseFromParent();
1327       return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_32RegClass, *MRI);
1328     }
1329 
1330     const unsigned BFE64 = Signed ? AMDGPU::S_BFE_I64 : AMDGPU::S_BFE_U64;
1331     const unsigned BFE32 = Signed ? AMDGPU::S_BFE_I32 : AMDGPU::S_BFE_U32;
1332 
1333     // Scalar BFE is encoded as S1[5:0] = offset, S1[22:16]= width.
1334     if (DstSize > 32 && SrcSize <= 32) {
1335       // We need a 64-bit register source, but the high bits don't matter.
1336       Register ExtReg = MRI->createVirtualRegister(&AMDGPU::SReg_64RegClass);
1337       Register UndefReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1338       BuildMI(MBB, I, DL, TII.get(AMDGPU::IMPLICIT_DEF), UndefReg);
1339       BuildMI(MBB, I, DL, TII.get(AMDGPU::REG_SEQUENCE), ExtReg)
1340         .addReg(SrcReg)
1341         .addImm(AMDGPU::sub0)
1342         .addReg(UndefReg)
1343         .addImm(AMDGPU::sub1);
1344 
1345       BuildMI(MBB, I, DL, TII.get(BFE64), DstReg)
1346         .addReg(ExtReg)
1347         .addImm(SrcSize << 16);
1348 
1349       I.eraseFromParent();
1350       return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_64RegClass, *MRI);
1351     }
1352 
1353     unsigned Mask;
1354     if (!Signed && shouldUseAndMask(SrcSize, Mask)) {
1355       BuildMI(MBB, I, DL, TII.get(AMDGPU::S_AND_B32), DstReg)
1356         .addReg(SrcReg)
1357         .addImm(Mask);
1358     } else {
1359       BuildMI(MBB, I, DL, TII.get(BFE32), DstReg)
1360         .addReg(SrcReg)
1361         .addImm(SrcSize << 16);
1362     }
1363 
1364     I.eraseFromParent();
1365     return RBI.constrainGenericRegister(DstReg, AMDGPU::SReg_32RegClass, *MRI);
1366   }
1367 
1368   return false;
1369 }
1370 
1371 bool AMDGPUInstructionSelector::selectG_CONSTANT(MachineInstr &I) const {
1372   MachineBasicBlock *BB = I.getParent();
1373   MachineOperand &ImmOp = I.getOperand(1);
1374 
1375   // The AMDGPU backend only supports Imm operands and not CImm or FPImm.
1376   if (ImmOp.isFPImm()) {
1377     const APInt &Imm = ImmOp.getFPImm()->getValueAPF().bitcastToAPInt();
1378     ImmOp.ChangeToImmediate(Imm.getZExtValue());
1379   } else if (ImmOp.isCImm()) {
1380     ImmOp.ChangeToImmediate(ImmOp.getCImm()->getZExtValue());
1381   }
1382 
1383   Register DstReg = I.getOperand(0).getReg();
1384   unsigned Size;
1385   bool IsSgpr;
1386   const RegisterBank *RB = MRI->getRegBankOrNull(I.getOperand(0).getReg());
1387   if (RB) {
1388     IsSgpr = RB->getID() == AMDGPU::SGPRRegBankID;
1389     Size = MRI->getType(DstReg).getSizeInBits();
1390   } else {
1391     const TargetRegisterClass *RC = TRI.getRegClassForReg(*MRI, DstReg);
1392     IsSgpr = TRI.isSGPRClass(RC);
1393     Size = TRI.getRegSizeInBits(*RC);
1394   }
1395 
1396   if (Size != 32 && Size != 64)
1397     return false;
1398 
1399   unsigned Opcode = IsSgpr ? AMDGPU::S_MOV_B32 : AMDGPU::V_MOV_B32_e32;
1400   if (Size == 32) {
1401     I.setDesc(TII.get(Opcode));
1402     I.addImplicitDefUseOperands(*MF);
1403     return constrainSelectedInstRegOperands(I, TII, TRI, RBI);
1404   }
1405 
1406   const DebugLoc &DL = I.getDebugLoc();
1407 
1408   APInt Imm(Size, I.getOperand(1).getImm());
1409 
1410   MachineInstr *ResInst;
1411   if (IsSgpr && TII.isInlineConstant(Imm)) {
1412     ResInst = BuildMI(*BB, &I, DL, TII.get(AMDGPU::S_MOV_B64), DstReg)
1413       .addImm(I.getOperand(1).getImm());
1414   } else {
1415     const TargetRegisterClass *RC = IsSgpr ?
1416       &AMDGPU::SReg_32RegClass : &AMDGPU::VGPR_32RegClass;
1417     Register LoReg = MRI->createVirtualRegister(RC);
1418     Register HiReg = MRI->createVirtualRegister(RC);
1419 
1420     BuildMI(*BB, &I, DL, TII.get(Opcode), LoReg)
1421       .addImm(Imm.trunc(32).getZExtValue());
1422 
1423     BuildMI(*BB, &I, DL, TII.get(Opcode), HiReg)
1424       .addImm(Imm.ashr(32).getZExtValue());
1425 
1426     ResInst = BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
1427       .addReg(LoReg)
1428       .addImm(AMDGPU::sub0)
1429       .addReg(HiReg)
1430       .addImm(AMDGPU::sub1);
1431   }
1432 
1433   // We can't call constrainSelectedInstRegOperands here, because it doesn't
1434   // work for target independent opcodes
1435   I.eraseFromParent();
1436   const TargetRegisterClass *DstRC =
1437     TRI.getConstrainedRegClassForOperand(ResInst->getOperand(0), *MRI);
1438   if (!DstRC)
1439     return true;
1440   return RBI.constrainGenericRegister(DstReg, *DstRC, *MRI);
1441 }
1442 
1443 bool AMDGPUInstructionSelector::selectG_FNEG(MachineInstr &MI) const {
1444   // Only manually handle the f64 SGPR case.
1445   //
1446   // FIXME: This is a workaround for 2.5 different tablegen problems. Because
1447   // the bit ops theoretically have a second result due to the implicit def of
1448   // SCC, the GlobalISelEmitter is overly conservative and rejects it. Fixing
1449   // that is easy by disabling the check. The result works, but uses a
1450   // nonsensical sreg32orlds_and_sreg_1 regclass.
1451   //
1452   // The DAG emitter is more problematic, and incorrectly adds both S_XOR_B32 to
1453   // the variadic REG_SEQUENCE operands.
1454 
1455   Register Dst = MI.getOperand(0).getReg();
1456   const RegisterBank *DstRB = RBI.getRegBank(Dst, *MRI, TRI);
1457   if (DstRB->getID() != AMDGPU::SGPRRegBankID ||
1458       MRI->getType(Dst) != LLT::scalar(64))
1459     return false;
1460 
1461   Register Src = MI.getOperand(1).getReg();
1462   MachineInstr *Fabs = getOpcodeDef(TargetOpcode::G_FABS, Src, *MRI);
1463   if (Fabs)
1464     Src = Fabs->getOperand(1).getReg();
1465 
1466   if (!RBI.constrainGenericRegister(Src, AMDGPU::SReg_64RegClass, *MRI) ||
1467       !RBI.constrainGenericRegister(Dst, AMDGPU::SReg_64RegClass, *MRI))
1468     return false;
1469 
1470   MachineBasicBlock *BB = MI.getParent();
1471   const DebugLoc &DL = MI.getDebugLoc();
1472   Register LoReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1473   Register HiReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1474   Register ConstReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1475   Register OpReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
1476 
1477   BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), LoReg)
1478     .addReg(Src, 0, AMDGPU::sub0);
1479   BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), HiReg)
1480     .addReg(Src, 0, AMDGPU::sub1);
1481   BuildMI(*BB, &MI, DL, TII.get(AMDGPU::S_MOV_B32), ConstReg)
1482     .addImm(0x80000000);
1483 
1484   // Set or toggle sign bit.
1485   unsigned Opc = Fabs ? AMDGPU::S_OR_B32 : AMDGPU::S_XOR_B32;
1486   BuildMI(*BB, &MI, DL, TII.get(Opc), OpReg)
1487     .addReg(HiReg)
1488     .addReg(ConstReg);
1489   BuildMI(*BB, &MI, DL, TII.get(AMDGPU::REG_SEQUENCE), Dst)
1490     .addReg(LoReg)
1491     .addImm(AMDGPU::sub0)
1492     .addReg(OpReg)
1493     .addImm(AMDGPU::sub1);
1494   MI.eraseFromParent();
1495   return true;
1496 }
1497 
1498 static bool isConstant(const MachineInstr &MI) {
1499   return MI.getOpcode() == TargetOpcode::G_CONSTANT;
1500 }
1501 
1502 void AMDGPUInstructionSelector::getAddrModeInfo(const MachineInstr &Load,
1503     const MachineRegisterInfo &MRI, SmallVectorImpl<GEPInfo> &AddrInfo) const {
1504 
1505   const MachineInstr *PtrMI = MRI.getUniqueVRegDef(Load.getOperand(1).getReg());
1506 
1507   assert(PtrMI);
1508 
1509   if (PtrMI->getOpcode() != TargetOpcode::G_PTR_ADD)
1510     return;
1511 
1512   GEPInfo GEPInfo(*PtrMI);
1513 
1514   for (unsigned i = 1; i != 3; ++i) {
1515     const MachineOperand &GEPOp = PtrMI->getOperand(i);
1516     const MachineInstr *OpDef = MRI.getUniqueVRegDef(GEPOp.getReg());
1517     assert(OpDef);
1518     if (i == 2 && isConstant(*OpDef)) {
1519       // TODO: Could handle constant base + variable offset, but a combine
1520       // probably should have commuted it.
1521       assert(GEPInfo.Imm == 0);
1522       GEPInfo.Imm = OpDef->getOperand(1).getCImm()->getSExtValue();
1523       continue;
1524     }
1525     const RegisterBank *OpBank = RBI.getRegBank(GEPOp.getReg(), MRI, TRI);
1526     if (OpBank->getID() == AMDGPU::SGPRRegBankID)
1527       GEPInfo.SgprParts.push_back(GEPOp.getReg());
1528     else
1529       GEPInfo.VgprParts.push_back(GEPOp.getReg());
1530   }
1531 
1532   AddrInfo.push_back(GEPInfo);
1533   getAddrModeInfo(*PtrMI, MRI, AddrInfo);
1534 }
1535 
1536 bool AMDGPUInstructionSelector::isInstrUniform(const MachineInstr &MI) const {
1537   if (!MI.hasOneMemOperand())
1538     return false;
1539 
1540   const MachineMemOperand *MMO = *MI.memoperands_begin();
1541   const Value *Ptr = MMO->getValue();
1542 
1543   // UndefValue means this is a load of a kernel input.  These are uniform.
1544   // Sometimes LDS instructions have constant pointers.
1545   // If Ptr is null, then that means this mem operand contains a
1546   // PseudoSourceValue like GOT.
1547   if (!Ptr || isa<UndefValue>(Ptr) || isa<Argument>(Ptr) ||
1548       isa<Constant>(Ptr) || isa<GlobalValue>(Ptr))
1549     return true;
1550 
1551   if (MMO->getAddrSpace() == AMDGPUAS::CONSTANT_ADDRESS_32BIT)
1552     return true;
1553 
1554   const Instruction *I = dyn_cast<Instruction>(Ptr);
1555   return I && I->getMetadata("amdgpu.uniform");
1556 }
1557 
1558 bool AMDGPUInstructionSelector::hasVgprParts(ArrayRef<GEPInfo> AddrInfo) const {
1559   for (const GEPInfo &GEPInfo : AddrInfo) {
1560     if (!GEPInfo.VgprParts.empty())
1561       return true;
1562   }
1563   return false;
1564 }
1565 
1566 void AMDGPUInstructionSelector::initM0(MachineInstr &I) const {
1567   MachineBasicBlock *BB = I.getParent();
1568 
1569   const LLT PtrTy = MRI->getType(I.getOperand(1).getReg());
1570   unsigned AS = PtrTy.getAddressSpace();
1571   if ((AS == AMDGPUAS::LOCAL_ADDRESS || AS == AMDGPUAS::REGION_ADDRESS) &&
1572       STI.ldsRequiresM0Init()) {
1573     // If DS instructions require M0 initializtion, insert it before selecting.
1574     BuildMI(*BB, &I, I.getDebugLoc(), TII.get(AMDGPU::S_MOV_B32), AMDGPU::M0)
1575       .addImm(-1);
1576   }
1577 }
1578 
1579 bool AMDGPUInstructionSelector::selectG_LOAD_ATOMICRMW(MachineInstr &I) const {
1580   initM0(I);
1581   return selectImpl(I, *CoverageInfo);
1582 }
1583 
1584 bool AMDGPUInstructionSelector::selectG_BRCOND(MachineInstr &I) const {
1585   MachineBasicBlock *BB = I.getParent();
1586   MachineOperand &CondOp = I.getOperand(0);
1587   Register CondReg = CondOp.getReg();
1588   const DebugLoc &DL = I.getDebugLoc();
1589 
1590   unsigned BrOpcode;
1591   Register CondPhysReg;
1592   const TargetRegisterClass *ConstrainRC;
1593 
1594   // In SelectionDAG, we inspect the IR block for uniformity metadata to decide
1595   // whether the branch is uniform when selecting the instruction. In
1596   // GlobalISel, we should push that decision into RegBankSelect. Assume for now
1597   // RegBankSelect knows what it's doing if the branch condition is scc, even
1598   // though it currently does not.
1599   if (!isVCC(CondReg, *MRI)) {
1600     if (MRI->getType(CondReg) != LLT::scalar(32))
1601       return false;
1602 
1603     CondPhysReg = AMDGPU::SCC;
1604     BrOpcode = AMDGPU::S_CBRANCH_SCC1;
1605     // FIXME: Hack for isSCC tests
1606     ConstrainRC = &AMDGPU::SGPR_32RegClass;
1607   } else {
1608     // FIXME: Do we have to insert an and with exec here, like in SelectionDAG?
1609     // We sort of know that a VCC producer based on the register bank, that ands
1610     // inactive lanes with 0. What if there was a logical operation with vcc
1611     // producers in different blocks/with different exec masks?
1612     // FIXME: Should scc->vcc copies and with exec?
1613     CondPhysReg = TRI.getVCC();
1614     BrOpcode = AMDGPU::S_CBRANCH_VCCNZ;
1615     ConstrainRC = TRI.getBoolRC();
1616   }
1617 
1618   if (!MRI->getRegClassOrNull(CondReg))
1619     MRI->setRegClass(CondReg, ConstrainRC);
1620 
1621   BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), CondPhysReg)
1622     .addReg(CondReg);
1623   BuildMI(*BB, &I, DL, TII.get(BrOpcode))
1624     .addMBB(I.getOperand(1).getMBB());
1625 
1626   I.eraseFromParent();
1627   return true;
1628 }
1629 
1630 bool AMDGPUInstructionSelector::selectG_FRAME_INDEX_GLOBAL_VALUE(
1631   MachineInstr &I) const {
1632   Register DstReg = I.getOperand(0).getReg();
1633   const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
1634   const bool IsVGPR = DstRB->getID() == AMDGPU::VGPRRegBankID;
1635   I.setDesc(TII.get(IsVGPR ? AMDGPU::V_MOV_B32_e32 : AMDGPU::S_MOV_B32));
1636   if (IsVGPR)
1637     I.addOperand(*MF, MachineOperand::CreateReg(AMDGPU::EXEC, false, true));
1638 
1639   return RBI.constrainGenericRegister(
1640     DstReg, IsVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass, *MRI);
1641 }
1642 
1643 bool AMDGPUInstructionSelector::selectG_PTR_MASK(MachineInstr &I) const {
1644   uint64_t Align = I.getOperand(2).getImm();
1645   const uint64_t Mask = ~((UINT64_C(1) << Align) - 1);
1646 
1647   MachineBasicBlock *BB = I.getParent();
1648 
1649   Register DstReg = I.getOperand(0).getReg();
1650   Register SrcReg = I.getOperand(1).getReg();
1651 
1652   const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
1653   const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
1654   const bool IsVGPR = DstRB->getID() == AMDGPU::VGPRRegBankID;
1655   unsigned NewOpc = IsVGPR ? AMDGPU::V_AND_B32_e64 : AMDGPU::S_AND_B32;
1656   unsigned MovOpc = IsVGPR ? AMDGPU::V_MOV_B32_e32 : AMDGPU::S_MOV_B32;
1657   const TargetRegisterClass &RegRC
1658     = IsVGPR ? AMDGPU::VGPR_32RegClass : AMDGPU::SReg_32RegClass;
1659 
1660   LLT Ty = MRI->getType(DstReg);
1661 
1662   const TargetRegisterClass *DstRC = TRI.getRegClassForTypeOnBank(Ty, *DstRB,
1663                                                                   *MRI);
1664   const TargetRegisterClass *SrcRC = TRI.getRegClassForTypeOnBank(Ty, *SrcRB,
1665                                                                   *MRI);
1666   if (!RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
1667       !RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI))
1668     return false;
1669 
1670   const DebugLoc &DL = I.getDebugLoc();
1671   Register ImmReg = MRI->createVirtualRegister(&RegRC);
1672   BuildMI(*BB, &I, DL, TII.get(MovOpc), ImmReg)
1673     .addImm(Mask);
1674 
1675   if (Ty.getSizeInBits() == 32) {
1676     BuildMI(*BB, &I, DL, TII.get(NewOpc), DstReg)
1677       .addReg(SrcReg)
1678       .addReg(ImmReg);
1679     I.eraseFromParent();
1680     return true;
1681   }
1682 
1683   Register HiReg = MRI->createVirtualRegister(&RegRC);
1684   Register LoReg = MRI->createVirtualRegister(&RegRC);
1685   Register MaskLo = MRI->createVirtualRegister(&RegRC);
1686 
1687   BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), LoReg)
1688     .addReg(SrcReg, 0, AMDGPU::sub0);
1689   BuildMI(*BB, &I, DL, TII.get(AMDGPU::COPY), HiReg)
1690     .addReg(SrcReg, 0, AMDGPU::sub1);
1691 
1692   BuildMI(*BB, &I, DL, TII.get(NewOpc), MaskLo)
1693     .addReg(LoReg)
1694     .addReg(ImmReg);
1695   BuildMI(*BB, &I, DL, TII.get(AMDGPU::REG_SEQUENCE), DstReg)
1696     .addReg(MaskLo)
1697     .addImm(AMDGPU::sub0)
1698     .addReg(HiReg)
1699     .addImm(AMDGPU::sub1);
1700   I.eraseFromParent();
1701   return true;
1702 }
1703 
1704 /// Return the register to use for the index value, and the subregister to use
1705 /// for the indirectly accessed register.
1706 static std::pair<Register, unsigned>
1707 computeIndirectRegIndex(MachineRegisterInfo &MRI,
1708                         const SIRegisterInfo &TRI,
1709                         const TargetRegisterClass *SuperRC,
1710                         Register IdxReg,
1711                         unsigned EltSize) {
1712   Register IdxBaseReg;
1713   int Offset;
1714   MachineInstr *Unused;
1715 
1716   std::tie(IdxBaseReg, Offset, Unused)
1717     = AMDGPU::getBaseWithConstantOffset(MRI, IdxReg);
1718 
1719   ArrayRef<int16_t> SubRegs = TRI.getRegSplitParts(SuperRC, EltSize);
1720 
1721   // Skip out of bounds offsets, or else we would end up using an undefined
1722   // register.
1723   if (static_cast<unsigned>(Offset) >= SubRegs.size())
1724     return std::make_pair(IdxReg, SubRegs[0]);
1725   return std::make_pair(IdxBaseReg, SubRegs[Offset]);
1726 }
1727 
1728 bool AMDGPUInstructionSelector::selectG_EXTRACT_VECTOR_ELT(
1729   MachineInstr &MI) const {
1730   Register DstReg = MI.getOperand(0).getReg();
1731   Register SrcReg = MI.getOperand(1).getReg();
1732   Register IdxReg = MI.getOperand(2).getReg();
1733 
1734   LLT DstTy = MRI->getType(DstReg);
1735   LLT SrcTy = MRI->getType(SrcReg);
1736 
1737   const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
1738   const RegisterBank *SrcRB = RBI.getRegBank(SrcReg, *MRI, TRI);
1739   const RegisterBank *IdxRB = RBI.getRegBank(IdxReg, *MRI, TRI);
1740 
1741   // The index must be scalar. If it wasn't RegBankSelect should have moved this
1742   // into a waterfall loop.
1743   if (IdxRB->getID() != AMDGPU::SGPRRegBankID)
1744     return false;
1745 
1746   const TargetRegisterClass *SrcRC = TRI.getRegClassForTypeOnBank(SrcTy, *SrcRB,
1747                                                                   *MRI);
1748   const TargetRegisterClass *DstRC = TRI.getRegClassForTypeOnBank(DstTy, *DstRB,
1749                                                                   *MRI);
1750   if (!RBI.constrainGenericRegister(SrcReg, *SrcRC, *MRI) ||
1751       !RBI.constrainGenericRegister(DstReg, *DstRC, *MRI) ||
1752       !RBI.constrainGenericRegister(IdxReg, AMDGPU::SReg_32RegClass, *MRI))
1753     return false;
1754 
1755   MachineBasicBlock *BB = MI.getParent();
1756   const DebugLoc &DL = MI.getDebugLoc();
1757   const bool Is64 = DstTy.getSizeInBits() == 64;
1758 
1759   unsigned SubReg;
1760   std::tie(IdxReg, SubReg) = computeIndirectRegIndex(*MRI, TRI, SrcRC, IdxReg,
1761                                                      DstTy.getSizeInBits() / 8);
1762 
1763   if (SrcRB->getID() == AMDGPU::SGPRRegBankID) {
1764     if (DstTy.getSizeInBits() != 32 && !Is64)
1765       return false;
1766 
1767     BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
1768       .addReg(IdxReg);
1769 
1770     unsigned Opc = Is64 ? AMDGPU::S_MOVRELS_B64 : AMDGPU::S_MOVRELS_B32;
1771     BuildMI(*BB, &MI, DL, TII.get(Opc), DstReg)
1772       .addReg(SrcReg, 0, SubReg)
1773       .addReg(SrcReg, RegState::Implicit);
1774     MI.eraseFromParent();
1775     return true;
1776   }
1777 
1778   if (SrcRB->getID() != AMDGPU::VGPRRegBankID || DstTy.getSizeInBits() != 32)
1779     return false;
1780 
1781   if (!STI.useVGPRIndexMode()) {
1782     BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
1783       .addReg(IdxReg);
1784     BuildMI(*BB, &MI, DL, TII.get(AMDGPU::V_MOVRELS_B32_e32), DstReg)
1785       .addReg(SrcReg, RegState::Undef, SubReg)
1786       .addReg(SrcReg, RegState::Implicit);
1787     MI.eraseFromParent();
1788     return true;
1789   }
1790 
1791   BuildMI(*BB, MI, DL, TII.get(AMDGPU::S_SET_GPR_IDX_ON))
1792     .addReg(IdxReg)
1793     .addImm(AMDGPU::VGPRIndexMode::SRC0_ENABLE);
1794   BuildMI(*BB, MI, DL, TII.get(AMDGPU::V_MOV_B32_e32), DstReg)
1795     .addReg(SrcReg, RegState::Undef, SubReg)
1796     .addReg(SrcReg, RegState::Implicit)
1797     .addReg(AMDGPU::M0, RegState::Implicit);
1798   BuildMI(*BB, MI, DL, TII.get(AMDGPU::S_SET_GPR_IDX_OFF));
1799 
1800   MI.eraseFromParent();
1801   return true;
1802 }
1803 
1804 // TODO: Fold insert_vector_elt (extract_vector_elt) into movrelsd
1805 bool AMDGPUInstructionSelector::selectG_INSERT_VECTOR_ELT(
1806   MachineInstr &MI) const {
1807   Register DstReg = MI.getOperand(0).getReg();
1808   Register VecReg = MI.getOperand(1).getReg();
1809   Register ValReg = MI.getOperand(2).getReg();
1810   Register IdxReg = MI.getOperand(3).getReg();
1811 
1812   LLT VecTy = MRI->getType(DstReg);
1813   LLT ValTy = MRI->getType(ValReg);
1814   unsigned VecSize = VecTy.getSizeInBits();
1815   unsigned ValSize = ValTy.getSizeInBits();
1816 
1817   const RegisterBank *VecRB = RBI.getRegBank(VecReg, *MRI, TRI);
1818   const RegisterBank *ValRB = RBI.getRegBank(ValReg, *MRI, TRI);
1819   const RegisterBank *IdxRB = RBI.getRegBank(IdxReg, *MRI, TRI);
1820 
1821   assert(VecTy.getElementType() == ValTy);
1822 
1823   // The index must be scalar. If it wasn't RegBankSelect should have moved this
1824   // into a waterfall loop.
1825   if (IdxRB->getID() != AMDGPU::SGPRRegBankID)
1826     return false;
1827 
1828   const TargetRegisterClass *VecRC = TRI.getRegClassForTypeOnBank(VecTy, *VecRB,
1829                                                                   *MRI);
1830   const TargetRegisterClass *ValRC = TRI.getRegClassForTypeOnBank(ValTy, *ValRB,
1831                                                                   *MRI);
1832 
1833   if (!RBI.constrainGenericRegister(VecReg, *VecRC, *MRI) ||
1834       !RBI.constrainGenericRegister(DstReg, *VecRC, *MRI) ||
1835       !RBI.constrainGenericRegister(ValReg, *ValRC, *MRI) ||
1836       !RBI.constrainGenericRegister(IdxReg, AMDGPU::SReg_32RegClass, *MRI))
1837     return false;
1838 
1839   if (VecRB->getID() == AMDGPU::VGPRRegBankID && ValSize != 32)
1840     return false;
1841 
1842   unsigned SubReg;
1843   std::tie(IdxReg, SubReg) = computeIndirectRegIndex(*MRI, TRI, VecRC, IdxReg,
1844                                                      ValSize / 8);
1845 
1846   const bool IndexMode = VecRB->getID() == AMDGPU::VGPRRegBankID &&
1847                          STI.useVGPRIndexMode();
1848 
1849   MachineBasicBlock *BB = MI.getParent();
1850   const DebugLoc &DL = MI.getDebugLoc();
1851 
1852   if (IndexMode) {
1853     BuildMI(*BB, MI, DL, TII.get(AMDGPU::S_SET_GPR_IDX_ON))
1854       .addReg(IdxReg)
1855       .addImm(AMDGPU::VGPRIndexMode::DST_ENABLE);
1856   } else {
1857     BuildMI(*BB, &MI, DL, TII.get(AMDGPU::COPY), AMDGPU::M0)
1858       .addReg(IdxReg);
1859   }
1860 
1861   const MCInstrDesc &RegWriteOp
1862     = TII.getIndirectRegWritePseudo(VecSize, ValSize,
1863                                     VecRB->getID() == AMDGPU::SGPRRegBankID);
1864   BuildMI(*BB, MI, DL, RegWriteOp, DstReg)
1865     .addReg(VecReg)
1866     .addReg(ValReg)
1867     .addImm(SubReg);
1868 
1869   if (IndexMode)
1870     BuildMI(*BB, MI, DL, TII.get(AMDGPU::S_SET_GPR_IDX_OFF));
1871 
1872   MI.eraseFromParent();
1873   return true;
1874 }
1875 
1876 bool AMDGPUInstructionSelector::select(MachineInstr &I) {
1877   if (I.isPHI())
1878     return selectPHI(I);
1879 
1880   if (!I.isPreISelOpcode()) {
1881     if (I.isCopy())
1882       return selectCOPY(I);
1883     return true;
1884   }
1885 
1886   switch (I.getOpcode()) {
1887   case TargetOpcode::G_AND:
1888   case TargetOpcode::G_OR:
1889   case TargetOpcode::G_XOR:
1890     if (selectG_AND_OR_XOR(I))
1891       return true;
1892     return selectImpl(I, *CoverageInfo);
1893   case TargetOpcode::G_ADD:
1894   case TargetOpcode::G_SUB:
1895     if (selectImpl(I, *CoverageInfo))
1896       return true;
1897     return selectG_ADD_SUB(I);
1898   case TargetOpcode::G_UADDO:
1899   case TargetOpcode::G_USUBO:
1900   case TargetOpcode::G_UADDE:
1901   case TargetOpcode::G_USUBE:
1902     return selectG_UADDO_USUBO_UADDE_USUBE(I);
1903   case TargetOpcode::G_INTTOPTR:
1904   case TargetOpcode::G_BITCAST:
1905   case TargetOpcode::G_PTRTOINT:
1906     return selectCOPY(I);
1907   case TargetOpcode::G_CONSTANT:
1908   case TargetOpcode::G_FCONSTANT:
1909     return selectG_CONSTANT(I);
1910   case TargetOpcode::G_FNEG:
1911     if (selectImpl(I, *CoverageInfo))
1912       return true;
1913     return selectG_FNEG(I);
1914   case TargetOpcode::G_EXTRACT:
1915     return selectG_EXTRACT(I);
1916   case TargetOpcode::G_MERGE_VALUES:
1917   case TargetOpcode::G_BUILD_VECTOR:
1918   case TargetOpcode::G_CONCAT_VECTORS:
1919     return selectG_MERGE_VALUES(I);
1920   case TargetOpcode::G_UNMERGE_VALUES:
1921     return selectG_UNMERGE_VALUES(I);
1922   case TargetOpcode::G_PTR_ADD:
1923     return selectG_PTR_ADD(I);
1924   case TargetOpcode::G_IMPLICIT_DEF:
1925     return selectG_IMPLICIT_DEF(I);
1926   case TargetOpcode::G_INSERT:
1927     return selectG_INSERT(I);
1928   case TargetOpcode::G_INTRINSIC:
1929     return selectG_INTRINSIC(I);
1930   case TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS:
1931     return selectG_INTRINSIC_W_SIDE_EFFECTS(I);
1932   case TargetOpcode::G_ICMP:
1933     if (selectG_ICMP(I))
1934       return true;
1935     return selectImpl(I, *CoverageInfo);
1936   case TargetOpcode::G_LOAD:
1937   case TargetOpcode::G_ATOMIC_CMPXCHG:
1938   case TargetOpcode::G_ATOMICRMW_XCHG:
1939   case TargetOpcode::G_ATOMICRMW_ADD:
1940   case TargetOpcode::G_ATOMICRMW_SUB:
1941   case TargetOpcode::G_ATOMICRMW_AND:
1942   case TargetOpcode::G_ATOMICRMW_OR:
1943   case TargetOpcode::G_ATOMICRMW_XOR:
1944   case TargetOpcode::G_ATOMICRMW_MIN:
1945   case TargetOpcode::G_ATOMICRMW_MAX:
1946   case TargetOpcode::G_ATOMICRMW_UMIN:
1947   case TargetOpcode::G_ATOMICRMW_UMAX:
1948   case TargetOpcode::G_ATOMICRMW_FADD:
1949     return selectG_LOAD_ATOMICRMW(I);
1950   case TargetOpcode::G_SELECT:
1951     return selectG_SELECT(I);
1952   case TargetOpcode::G_STORE:
1953     return selectG_STORE(I);
1954   case TargetOpcode::G_TRUNC:
1955     return selectG_TRUNC(I);
1956   case TargetOpcode::G_SEXT:
1957   case TargetOpcode::G_ZEXT:
1958   case TargetOpcode::G_ANYEXT:
1959     if (selectImpl(I, *CoverageInfo))
1960       return true;
1961     return selectG_SZA_EXT(I);
1962   case TargetOpcode::G_BRCOND:
1963     return selectG_BRCOND(I);
1964   case TargetOpcode::G_FRAME_INDEX:
1965   case TargetOpcode::G_GLOBAL_VALUE:
1966     return selectG_FRAME_INDEX_GLOBAL_VALUE(I);
1967   case TargetOpcode::G_PTR_MASK:
1968     return selectG_PTR_MASK(I);
1969   case TargetOpcode::G_EXTRACT_VECTOR_ELT:
1970     return selectG_EXTRACT_VECTOR_ELT(I);
1971   case TargetOpcode::G_INSERT_VECTOR_ELT:
1972     return selectG_INSERT_VECTOR_ELT(I);
1973   case AMDGPU::G_AMDGPU_ATOMIC_INC:
1974   case AMDGPU::G_AMDGPU_ATOMIC_DEC:
1975     initM0(I);
1976     return selectImpl(I, *CoverageInfo);
1977   default:
1978     return selectImpl(I, *CoverageInfo);
1979   }
1980   return false;
1981 }
1982 
1983 InstructionSelector::ComplexRendererFns
1984 AMDGPUInstructionSelector::selectVCSRC(MachineOperand &Root) const {
1985   return {{
1986       [=](MachineInstrBuilder &MIB) { MIB.add(Root); }
1987   }};
1988 
1989 }
1990 
1991 std::pair<Register, unsigned>
1992 AMDGPUInstructionSelector::selectVOP3ModsImpl(
1993   Register Src) const {
1994   unsigned Mods = 0;
1995   MachineInstr *MI = getDefIgnoringCopies(Src, *MRI);
1996 
1997   if (MI && MI->getOpcode() == AMDGPU::G_FNEG) {
1998     Src = MI->getOperand(1).getReg();
1999     Mods |= SISrcMods::NEG;
2000     MI = getDefIgnoringCopies(Src, *MRI);
2001   }
2002 
2003   if (MI && MI->getOpcode() == AMDGPU::G_FABS) {
2004     Src = MI->getOperand(1).getReg();
2005     Mods |= SISrcMods::ABS;
2006   }
2007 
2008   return std::make_pair(Src, Mods);
2009 }
2010 
2011 ///
2012 /// This will select either an SGPR or VGPR operand and will save us from
2013 /// having to write an extra tablegen pattern.
2014 InstructionSelector::ComplexRendererFns
2015 AMDGPUInstructionSelector::selectVSRC0(MachineOperand &Root) const {
2016   return {{
2017       [=](MachineInstrBuilder &MIB) { MIB.add(Root); }
2018   }};
2019 }
2020 
2021 InstructionSelector::ComplexRendererFns
2022 AMDGPUInstructionSelector::selectVOP3Mods0(MachineOperand &Root) const {
2023   Register Src;
2024   unsigned Mods;
2025   std::tie(Src, Mods) = selectVOP3ModsImpl(Root.getReg());
2026 
2027   return {{
2028       [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
2029       [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }, // src0_mods
2030       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },    // clamp
2031       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }     // omod
2032   }};
2033 }
2034 
2035 InstructionSelector::ComplexRendererFns
2036 AMDGPUInstructionSelector::selectVOP3OMods(MachineOperand &Root) const {
2037   return {{
2038       [=](MachineInstrBuilder &MIB) { MIB.add(Root); },
2039       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }, // clamp
2040       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }  // omod
2041   }};
2042 }
2043 
2044 InstructionSelector::ComplexRendererFns
2045 AMDGPUInstructionSelector::selectVOP3Mods(MachineOperand &Root) const {
2046   Register Src;
2047   unsigned Mods;
2048   std::tie(Src, Mods) = selectVOP3ModsImpl(Root.getReg());
2049 
2050   return {{
2051       [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
2052       [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }  // src_mods
2053   }};
2054 }
2055 
2056 InstructionSelector::ComplexRendererFns
2057 AMDGPUInstructionSelector::selectVOP3NoMods(MachineOperand &Root) const {
2058   Register Reg = Root.getReg();
2059   const MachineInstr *Def = getDefIgnoringCopies(Reg, *MRI);
2060   if (Def && (Def->getOpcode() == AMDGPU::G_FNEG ||
2061               Def->getOpcode() == AMDGPU::G_FABS))
2062     return {};
2063   return {{
2064       [=](MachineInstrBuilder &MIB) { MIB.addReg(Reg); },
2065   }};
2066 }
2067 
2068 InstructionSelector::ComplexRendererFns
2069 AMDGPUInstructionSelector::selectVOP3Mods_nnan(MachineOperand &Root) const {
2070   Register Src;
2071   unsigned Mods;
2072   std::tie(Src, Mods) = selectVOP3ModsImpl(Root.getReg());
2073   if (!TM.Options.NoNaNsFPMath && !isKnownNeverNaN(Src, *MRI))
2074     return None;
2075 
2076   return {{
2077       [=](MachineInstrBuilder &MIB) { MIB.addReg(Src); },
2078       [=](MachineInstrBuilder &MIB) { MIB.addImm(Mods); }  // src_mods
2079   }};
2080 }
2081 
2082 InstructionSelector::ComplexRendererFns
2083 AMDGPUInstructionSelector::selectVOP3OpSelMods0(MachineOperand &Root) const {
2084   // FIXME: Handle clamp and op_sel
2085   return {{
2086       [=](MachineInstrBuilder &MIB) { MIB.addReg(Root.getReg()); },
2087       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }, // src_mods
2088       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }  // clamp
2089   }};
2090 }
2091 
2092 InstructionSelector::ComplexRendererFns
2093 AMDGPUInstructionSelector::selectVOP3OpSelMods(MachineOperand &Root) const {
2094   // FIXME: Handle op_sel
2095   return {{
2096       [=](MachineInstrBuilder &MIB) { MIB.addReg(Root.getReg()); },
2097       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); } // src_mods
2098   }};
2099 }
2100 
2101 InstructionSelector::ComplexRendererFns
2102 AMDGPUInstructionSelector::selectSmrdImm(MachineOperand &Root) const {
2103   SmallVector<GEPInfo, 4> AddrInfo;
2104   getAddrModeInfo(*Root.getParent(), *MRI, AddrInfo);
2105 
2106   if (AddrInfo.empty() || AddrInfo[0].SgprParts.size() != 1)
2107     return None;
2108 
2109   const GEPInfo &GEPInfo = AddrInfo[0];
2110 
2111   if (!AMDGPU::isLegalSMRDImmOffset(STI, GEPInfo.Imm))
2112     return None;
2113 
2114   unsigned PtrReg = GEPInfo.SgprParts[0];
2115   int64_t EncodedImm = AMDGPU::getSMRDEncodedOffset(STI, GEPInfo.Imm);
2116   return {{
2117     [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrReg); },
2118     [=](MachineInstrBuilder &MIB) { MIB.addImm(EncodedImm); }
2119   }};
2120 }
2121 
2122 InstructionSelector::ComplexRendererFns
2123 AMDGPUInstructionSelector::selectSmrdImm32(MachineOperand &Root) const {
2124   SmallVector<GEPInfo, 4> AddrInfo;
2125   getAddrModeInfo(*Root.getParent(), *MRI, AddrInfo);
2126 
2127   if (AddrInfo.empty() || AddrInfo[0].SgprParts.size() != 1)
2128     return None;
2129 
2130   const GEPInfo &GEPInfo = AddrInfo[0];
2131   unsigned PtrReg = GEPInfo.SgprParts[0];
2132   int64_t EncodedImm = AMDGPU::getSMRDEncodedOffset(STI, GEPInfo.Imm);
2133   if (!isUInt<32>(EncodedImm))
2134     return None;
2135 
2136   return {{
2137     [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrReg); },
2138     [=](MachineInstrBuilder &MIB) { MIB.addImm(EncodedImm); }
2139   }};
2140 }
2141 
2142 InstructionSelector::ComplexRendererFns
2143 AMDGPUInstructionSelector::selectSmrdSgpr(MachineOperand &Root) const {
2144   MachineInstr *MI = Root.getParent();
2145   MachineBasicBlock *MBB = MI->getParent();
2146 
2147   SmallVector<GEPInfo, 4> AddrInfo;
2148   getAddrModeInfo(*MI, *MRI, AddrInfo);
2149 
2150   // FIXME: We should shrink the GEP if the offset is known to be <= 32-bits,
2151   // then we can select all ptr + 32-bit offsets not just immediate offsets.
2152   if (AddrInfo.empty() || AddrInfo[0].SgprParts.size() != 1)
2153     return None;
2154 
2155   const GEPInfo &GEPInfo = AddrInfo[0];
2156   if (!GEPInfo.Imm || !isUInt<32>(GEPInfo.Imm))
2157     return None;
2158 
2159   // If we make it this far we have a load with an 32-bit immediate offset.
2160   // It is OK to select this using a sgpr offset, because we have already
2161   // failed trying to select this load into one of the _IMM variants since
2162   // the _IMM Patterns are considered before the _SGPR patterns.
2163   unsigned PtrReg = GEPInfo.SgprParts[0];
2164   Register OffsetReg = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
2165   BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::S_MOV_B32), OffsetReg)
2166           .addImm(GEPInfo.Imm);
2167   return {{
2168     [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrReg); },
2169     [=](MachineInstrBuilder &MIB) { MIB.addReg(OffsetReg); }
2170   }};
2171 }
2172 
2173 template <bool Signed>
2174 InstructionSelector::ComplexRendererFns
2175 AMDGPUInstructionSelector::selectFlatOffsetImpl(MachineOperand &Root) const {
2176   MachineInstr *MI = Root.getParent();
2177 
2178   InstructionSelector::ComplexRendererFns Default = {{
2179       [=](MachineInstrBuilder &MIB) { MIB.addReg(Root.getReg()); },
2180       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },  // offset
2181       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }  // slc
2182     }};
2183 
2184   if (!STI.hasFlatInstOffsets())
2185     return Default;
2186 
2187   const MachineInstr *OpDef = MRI->getVRegDef(Root.getReg());
2188   if (!OpDef || OpDef->getOpcode() != AMDGPU::G_PTR_ADD)
2189     return Default;
2190 
2191   Optional<int64_t> Offset =
2192     getConstantVRegVal(OpDef->getOperand(2).getReg(), *MRI);
2193   if (!Offset.hasValue())
2194     return Default;
2195 
2196   unsigned AddrSpace = (*MI->memoperands_begin())->getAddrSpace();
2197   if (!TII.isLegalFLATOffset(Offset.getValue(), AddrSpace, Signed))
2198     return Default;
2199 
2200   Register BasePtr = OpDef->getOperand(1).getReg();
2201 
2202   return {{
2203       [=](MachineInstrBuilder &MIB) { MIB.addReg(BasePtr); },
2204       [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset.getValue()); },
2205       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); }  // slc
2206     }};
2207 }
2208 
2209 InstructionSelector::ComplexRendererFns
2210 AMDGPUInstructionSelector::selectFlatOffset(MachineOperand &Root) const {
2211   return selectFlatOffsetImpl<false>(Root);
2212 }
2213 
2214 InstructionSelector::ComplexRendererFns
2215 AMDGPUInstructionSelector::selectFlatOffsetSigned(MachineOperand &Root) const {
2216   return selectFlatOffsetImpl<true>(Root);
2217 }
2218 
2219 static bool isStackPtrRelative(const MachinePointerInfo &PtrInfo) {
2220   auto PSV = PtrInfo.V.dyn_cast<const PseudoSourceValue *>();
2221   return PSV && PSV->isStack();
2222 }
2223 
2224 InstructionSelector::ComplexRendererFns
2225 AMDGPUInstructionSelector::selectMUBUFScratchOffen(MachineOperand &Root) const {
2226   MachineInstr *MI = Root.getParent();
2227   MachineBasicBlock *MBB = MI->getParent();
2228   MachineFunction *MF = MBB->getParent();
2229   const SIMachineFunctionInfo *Info = MF->getInfo<SIMachineFunctionInfo>();
2230 
2231   int64_t Offset = 0;
2232   if (mi_match(Root.getReg(), *MRI, m_ICst(Offset))) {
2233     Register HighBits = MRI->createVirtualRegister(&AMDGPU::VGPR_32RegClass);
2234 
2235     // TODO: Should this be inside the render function? The iterator seems to
2236     // move.
2237     BuildMI(*MBB, MI, MI->getDebugLoc(), TII.get(AMDGPU::V_MOV_B32_e32),
2238             HighBits)
2239       .addImm(Offset & ~4095);
2240 
2241     return {{[=](MachineInstrBuilder &MIB) { // rsrc
2242                MIB.addReg(Info->getScratchRSrcReg());
2243              },
2244              [=](MachineInstrBuilder &MIB) { // vaddr
2245                MIB.addReg(HighBits);
2246              },
2247              [=](MachineInstrBuilder &MIB) { // soffset
2248                const MachineMemOperand *MMO = *MI->memoperands_begin();
2249                const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
2250 
2251                Register SOffsetReg = isStackPtrRelative(PtrInfo)
2252                                          ? Info->getStackPtrOffsetReg()
2253                                          : Info->getScratchWaveOffsetReg();
2254                MIB.addReg(SOffsetReg);
2255              },
2256              [=](MachineInstrBuilder &MIB) { // offset
2257                MIB.addImm(Offset & 4095);
2258              }}};
2259   }
2260 
2261   assert(Offset == 0);
2262 
2263   // Try to fold a frame index directly into the MUBUF vaddr field, and any
2264   // offsets.
2265   Optional<int> FI;
2266   Register VAddr = Root.getReg();
2267   if (const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg())) {
2268     if (isBaseWithConstantOffset(Root, *MRI)) {
2269       const MachineOperand &LHS = RootDef->getOperand(1);
2270       const MachineOperand &RHS = RootDef->getOperand(2);
2271       const MachineInstr *LHSDef = MRI->getVRegDef(LHS.getReg());
2272       const MachineInstr *RHSDef = MRI->getVRegDef(RHS.getReg());
2273       if (LHSDef && RHSDef) {
2274         int64_t PossibleOffset =
2275             RHSDef->getOperand(1).getCImm()->getSExtValue();
2276         if (SIInstrInfo::isLegalMUBUFImmOffset(PossibleOffset) &&
2277             (!STI.privateMemoryResourceIsRangeChecked() ||
2278              KnownBits->signBitIsZero(LHS.getReg()))) {
2279           if (LHSDef->getOpcode() == AMDGPU::G_FRAME_INDEX)
2280             FI = LHSDef->getOperand(1).getIndex();
2281           else
2282             VAddr = LHS.getReg();
2283           Offset = PossibleOffset;
2284         }
2285       }
2286     } else if (RootDef->getOpcode() == AMDGPU::G_FRAME_INDEX) {
2287       FI = RootDef->getOperand(1).getIndex();
2288     }
2289   }
2290 
2291   // If we don't know this private access is a local stack object, it needs to
2292   // be relative to the entry point's scratch wave offset register.
2293   // TODO: Should split large offsets that don't fit like above.
2294   // TODO: Don't use scratch wave offset just because the offset didn't fit.
2295   Register SOffset = FI.hasValue() ? Info->getStackPtrOffsetReg()
2296                                    : Info->getScratchWaveOffsetReg();
2297 
2298   return {{[=](MachineInstrBuilder &MIB) { // rsrc
2299              MIB.addReg(Info->getScratchRSrcReg());
2300            },
2301            [=](MachineInstrBuilder &MIB) { // vaddr
2302              if (FI.hasValue())
2303                MIB.addFrameIndex(FI.getValue());
2304              else
2305                MIB.addReg(VAddr);
2306            },
2307            [=](MachineInstrBuilder &MIB) { // soffset
2308              MIB.addReg(SOffset);
2309            },
2310            [=](MachineInstrBuilder &MIB) { // offset
2311              MIB.addImm(Offset);
2312            }}};
2313 }
2314 
2315 bool AMDGPUInstructionSelector::isDSOffsetLegal(Register Base,
2316                                                 int64_t Offset,
2317                                                 unsigned OffsetBits) const {
2318   if ((OffsetBits == 16 && !isUInt<16>(Offset)) ||
2319       (OffsetBits == 8 && !isUInt<8>(Offset)))
2320     return false;
2321 
2322   if (STI.hasUsableDSOffset() || STI.unsafeDSOffsetFoldingEnabled())
2323     return true;
2324 
2325   // On Southern Islands instruction with a negative base value and an offset
2326   // don't seem to work.
2327   return KnownBits->signBitIsZero(Base);
2328 }
2329 
2330 InstructionSelector::ComplexRendererFns
2331 AMDGPUInstructionSelector::selectMUBUFScratchOffset(
2332     MachineOperand &Root) const {
2333   MachineInstr *MI = Root.getParent();
2334   MachineBasicBlock *MBB = MI->getParent();
2335 
2336   int64_t Offset = 0;
2337   if (!mi_match(Root.getReg(), *MRI, m_ICst(Offset)) ||
2338       !SIInstrInfo::isLegalMUBUFImmOffset(Offset))
2339     return {};
2340 
2341   const MachineFunction *MF = MBB->getParent();
2342   const SIMachineFunctionInfo *Info = MF->getInfo<SIMachineFunctionInfo>();
2343   const MachineMemOperand *MMO = *MI->memoperands_begin();
2344   const MachinePointerInfo &PtrInfo = MMO->getPointerInfo();
2345 
2346   Register SOffsetReg = isStackPtrRelative(PtrInfo)
2347                             ? Info->getStackPtrOffsetReg()
2348                             : Info->getScratchWaveOffsetReg();
2349   return {{
2350       [=](MachineInstrBuilder &MIB) {
2351         MIB.addReg(Info->getScratchRSrcReg());
2352       },                                                         // rsrc
2353       [=](MachineInstrBuilder &MIB) { MIB.addReg(SOffsetReg); }, // soffset
2354       [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }      // offset
2355   }};
2356 }
2357 
2358 std::pair<Register, unsigned>
2359 AMDGPUInstructionSelector::selectDS1Addr1OffsetImpl(MachineOperand &Root) const {
2360   const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg());
2361   if (!RootDef)
2362     return std::make_pair(Root.getReg(), 0);
2363 
2364   int64_t ConstAddr = 0;
2365   if (isBaseWithConstantOffset(Root, *MRI)) {
2366     const MachineOperand &LHS = RootDef->getOperand(1);
2367     const MachineOperand &RHS = RootDef->getOperand(2);
2368     const MachineInstr *LHSDef = MRI->getVRegDef(LHS.getReg());
2369     const MachineInstr *RHSDef = MRI->getVRegDef(RHS.getReg());
2370     if (LHSDef && RHSDef) {
2371       int64_t PossibleOffset =
2372         RHSDef->getOperand(1).getCImm()->getSExtValue();
2373       if (isDSOffsetLegal(LHS.getReg(), PossibleOffset, 16)) {
2374         // (add n0, c0)
2375         return std::make_pair(LHS.getReg(), PossibleOffset);
2376       }
2377     }
2378   } else if (RootDef->getOpcode() == AMDGPU::G_SUB) {
2379     // TODO
2380 
2381 
2382   } else if (mi_match(Root.getReg(), *MRI, m_ICst(ConstAddr))) {
2383     // TODO
2384 
2385   }
2386 
2387   return std::make_pair(Root.getReg(), 0);
2388 }
2389 
2390 InstructionSelector::ComplexRendererFns
2391 AMDGPUInstructionSelector::selectDS1Addr1Offset(MachineOperand &Root) const {
2392 
2393   Register Reg;
2394   unsigned Offset;
2395   std::tie(Reg, Offset) = selectDS1Addr1OffsetImpl(Root);
2396   return {{
2397       [=](MachineInstrBuilder &MIB) { MIB.addReg(Reg); },
2398       [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }
2399     }};
2400 }
2401 
2402 InstructionSelector::ComplexRendererFns
2403 AMDGPUInstructionSelector::selectDS64Bit4ByteAligned(MachineOperand &Root) const {
2404   const MachineInstr *RootDef = MRI->getVRegDef(Root.getReg());
2405   if (!RootDef) {
2406     return {{
2407         [=](MachineInstrBuilder &MIB) { MIB.add(Root); },
2408         [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },
2409         [=](MachineInstrBuilder &MIB) { MIB.addImm(1); }
2410       }};
2411   }
2412 
2413   int64_t ConstAddr = 0;
2414   Register PtrBase;
2415   int64_t Offset;
2416 
2417   std::tie(PtrBase, Offset) =
2418     getPtrBaseWithConstantOffset(Root.getReg(), *MRI);
2419 
2420   if (Offset) {
2421     int64_t DWordOffset0 = Offset / 4;
2422     int64_t DWordOffset1 = DWordOffset0 + 1;
2423     if (isDSOffsetLegal(PtrBase, DWordOffset1, 8)) {
2424       // (add n0, c0)
2425       return {{
2426           [=](MachineInstrBuilder &MIB) { MIB.addReg(PtrBase); },
2427           [=](MachineInstrBuilder &MIB) { MIB.addImm(DWordOffset0); },
2428           [=](MachineInstrBuilder &MIB) { MIB.addImm(DWordOffset1); }
2429         }};
2430     }
2431   } else if (RootDef->getOpcode() == AMDGPU::G_SUB) {
2432     // TODO
2433 
2434   } else if (mi_match(Root.getReg(), *MRI, m_ICst(ConstAddr))) {
2435     // TODO
2436 
2437   }
2438 
2439   return {{
2440       [=](MachineInstrBuilder &MIB) { MIB.add(Root); },
2441       [=](MachineInstrBuilder &MIB) { MIB.addImm(0); },
2442       [=](MachineInstrBuilder &MIB) { MIB.addImm(1); }
2443     }};
2444 }
2445 
2446 /// If \p Root is a G_PTR_ADD with a G_CONSTANT on the right hand side, return
2447 /// the base value with the constant offset. There may be intervening copies
2448 /// between \p Root and the identified constant. Returns \p Root, 0 if this does
2449 /// not match the pattern.
2450 std::pair<Register, int64_t>
2451 AMDGPUInstructionSelector::getPtrBaseWithConstantOffset(
2452   Register Root, const MachineRegisterInfo &MRI) const {
2453   MachineInstr *RootI = MRI.getVRegDef(Root);
2454   if (RootI->getOpcode() != TargetOpcode::G_PTR_ADD)
2455     return {Root, 0};
2456 
2457   MachineOperand &RHS = RootI->getOperand(2);
2458   Optional<ValueAndVReg> MaybeOffset
2459     = getConstantVRegValWithLookThrough(RHS.getReg(), MRI, true);
2460   if (!MaybeOffset)
2461     return {Root, 0};
2462   return {RootI->getOperand(1).getReg(), MaybeOffset->Value};
2463 }
2464 
2465 static void addZeroImm(MachineInstrBuilder &MIB) {
2466   MIB.addImm(0);
2467 }
2468 
2469 /// Return a resource descriptor for use with an arbitrary 64-bit pointer. If \p
2470 /// BasePtr is not valid, a null base pointer will be used.
2471 static Register buildRSRC(MachineIRBuilder &B, MachineRegisterInfo &MRI,
2472                           uint32_t FormatLo, uint32_t FormatHi,
2473                           Register BasePtr) {
2474   Register RSrc2 = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
2475   Register RSrc3 = MRI.createVirtualRegister(&AMDGPU::SReg_32RegClass);
2476   Register RSrcHi = MRI.createVirtualRegister(&AMDGPU::SReg_64RegClass);
2477   Register RSrc = MRI.createVirtualRegister(&AMDGPU::SGPR_128RegClass);
2478 
2479   B.buildInstr(AMDGPU::S_MOV_B32)
2480     .addDef(RSrc2)
2481     .addImm(FormatLo);
2482   B.buildInstr(AMDGPU::S_MOV_B32)
2483     .addDef(RSrc3)
2484     .addImm(FormatHi);
2485 
2486   // Build the half of the subregister with the constants before building the
2487   // full 128-bit register. If we are building multiple resource descriptors,
2488   // this will allow CSEing of the 2-component register.
2489   B.buildInstr(AMDGPU::REG_SEQUENCE)
2490     .addDef(RSrcHi)
2491     .addReg(RSrc2)
2492     .addImm(AMDGPU::sub0)
2493     .addReg(RSrc3)
2494     .addImm(AMDGPU::sub1);
2495 
2496   Register RSrcLo = BasePtr;
2497   if (!BasePtr) {
2498     RSrcLo = MRI.createVirtualRegister(&AMDGPU::SReg_64RegClass);
2499     B.buildInstr(AMDGPU::S_MOV_B64)
2500       .addDef(RSrcLo)
2501       .addImm(0);
2502   }
2503 
2504   B.buildInstr(AMDGPU::REG_SEQUENCE)
2505     .addDef(RSrc)
2506     .addReg(RSrcLo)
2507     .addImm(AMDGPU::sub0_sub1)
2508     .addReg(RSrcHi)
2509     .addImm(AMDGPU::sub2_sub3);
2510 
2511   return RSrc;
2512 }
2513 
2514 static Register buildAddr64RSrc(MachineIRBuilder &B, MachineRegisterInfo &MRI,
2515                                 const SIInstrInfo &TII, Register BasePtr) {
2516   uint64_t DefaultFormat = TII.getDefaultRsrcDataFormat();
2517 
2518   // FIXME: Why are half the "default" bits ignored based on the addressing
2519   // mode?
2520   return buildRSRC(B, MRI, 0, Hi_32(DefaultFormat), BasePtr);
2521 }
2522 
2523 static Register buildOffsetSrc(MachineIRBuilder &B, MachineRegisterInfo &MRI,
2524                                const SIInstrInfo &TII, Register BasePtr) {
2525   uint64_t DefaultFormat = TII.getDefaultRsrcDataFormat();
2526 
2527   // FIXME: Why are half the "default" bits ignored based on the addressing
2528   // mode?
2529   return buildRSRC(B, MRI, -1, Hi_32(DefaultFormat), BasePtr);
2530 }
2531 
2532 AMDGPUInstructionSelector::MUBUFAddressData
2533 AMDGPUInstructionSelector::parseMUBUFAddress(Register Src) const {
2534   MUBUFAddressData Data;
2535   Data.N0 = Src;
2536 
2537   Register PtrBase;
2538   int64_t Offset;
2539 
2540   std::tie(PtrBase, Offset) = getPtrBaseWithConstantOffset(Src, *MRI);
2541   if (isUInt<32>(Offset)) {
2542     Data.N0 = PtrBase;
2543     Data.Offset = Offset;
2544   }
2545 
2546   if (MachineInstr *InputAdd
2547       = getOpcodeDef(TargetOpcode::G_PTR_ADD, Data.N0, *MRI)) {
2548     Data.N2 = InputAdd->getOperand(1).getReg();
2549     Data.N3 = InputAdd->getOperand(2).getReg();
2550 
2551     // FIXME: Need to fix extra SGPR->VGPRcopies inserted
2552     // FIXME: Don't know this was defined by operand 0
2553     //
2554     // TODO: Remove this when we have copy folding optimizations after
2555     // RegBankSelect.
2556     Data.N2 = getDefIgnoringCopies(Data.N2, *MRI)->getOperand(0).getReg();
2557     Data.N3 = getDefIgnoringCopies(Data.N3, *MRI)->getOperand(0).getReg();
2558   }
2559 
2560   return Data;
2561 }
2562 
2563 /// Return if the addr64 mubuf mode should be used for the given address.
2564 bool AMDGPUInstructionSelector::shouldUseAddr64(MUBUFAddressData Addr) const {
2565   // (ptr_add N2, N3) -> addr64, or
2566   // (ptr_add (ptr_add N2, N3), C1) -> addr64
2567   if (Addr.N2)
2568     return true;
2569 
2570   const RegisterBank *N0Bank = RBI.getRegBank(Addr.N0, *MRI, TRI);
2571   return N0Bank->getID() == AMDGPU::VGPRRegBankID;
2572 }
2573 
2574 /// Split an immediate offset \p ImmOffset depending on whether it fits in the
2575 /// immediate field. Modifies \p ImmOffset and sets \p SOffset to the variable
2576 /// component.
2577 void AMDGPUInstructionSelector::splitIllegalMUBUFOffset(
2578   MachineIRBuilder &B, Register &SOffset, int64_t &ImmOffset) const {
2579   if (SIInstrInfo::isLegalMUBUFImmOffset(ImmOffset))
2580     return;
2581 
2582   // Illegal offset, store it in soffset.
2583   SOffset = MRI->createVirtualRegister(&AMDGPU::SReg_32RegClass);
2584   B.buildInstr(AMDGPU::S_MOV_B32)
2585     .addDef(SOffset)
2586     .addImm(ImmOffset);
2587   ImmOffset = 0;
2588 }
2589 
2590 bool AMDGPUInstructionSelector::selectMUBUFAddr64Impl(
2591   MachineOperand &Root, Register &VAddr, Register &RSrcReg,
2592   Register &SOffset, int64_t &Offset) const {
2593   // FIXME: Predicates should stop this from reaching here.
2594   // addr64 bit was removed for volcanic islands.
2595   if (!STI.hasAddr64() || STI.useFlatForGlobal())
2596     return false;
2597 
2598   MUBUFAddressData AddrData = parseMUBUFAddress(Root.getReg());
2599   if (!shouldUseAddr64(AddrData))
2600     return false;
2601 
2602   Register N0 = AddrData.N0;
2603   Register N2 = AddrData.N2;
2604   Register N3 = AddrData.N3;
2605   Offset = AddrData.Offset;
2606 
2607   // Base pointer for the SRD.
2608   Register SRDPtr;
2609 
2610   if (N2) {
2611     if (RBI.getRegBank(N2, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
2612       assert(N3);
2613       if (RBI.getRegBank(N3, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
2614         // Both N2 and N3 are divergent. Use N0 (the result of the add) as the
2615         // addr64, and construct the default resource from a 0 address.
2616         VAddr = N0;
2617       } else {
2618         SRDPtr = N3;
2619         VAddr = N2;
2620       }
2621     } else {
2622       // N2 is not divergent.
2623       SRDPtr = N2;
2624       VAddr = N3;
2625     }
2626   } else if (RBI.getRegBank(N0, *MRI, TRI)->getID() == AMDGPU::VGPRRegBankID) {
2627     // Use the default null pointer in the resource
2628     VAddr = N0;
2629   } else {
2630     // N0 -> offset, or
2631     // (N0 + C1) -> offset
2632     SRDPtr = N0;
2633   }
2634 
2635   MachineIRBuilder B(*Root.getParent());
2636   RSrcReg = buildAddr64RSrc(B, *MRI, TII, SRDPtr);
2637   splitIllegalMUBUFOffset(B, SOffset, Offset);
2638   return true;
2639 }
2640 
2641 bool AMDGPUInstructionSelector::selectMUBUFOffsetImpl(
2642   MachineOperand &Root, Register &RSrcReg, Register &SOffset,
2643   int64_t &Offset) const {
2644   MUBUFAddressData AddrData = parseMUBUFAddress(Root.getReg());
2645   if (shouldUseAddr64(AddrData))
2646     return false;
2647 
2648   // N0 -> offset, or
2649   // (N0 + C1) -> offset
2650   Register SRDPtr = AddrData.N0;
2651   Offset = AddrData.Offset;
2652 
2653   // TODO: Look through extensions for 32-bit soffset.
2654   MachineIRBuilder B(*Root.getParent());
2655 
2656   RSrcReg = buildOffsetSrc(B, *MRI, TII, SRDPtr);
2657   splitIllegalMUBUFOffset(B, SOffset, Offset);
2658   return true;
2659 }
2660 
2661 InstructionSelector::ComplexRendererFns
2662 AMDGPUInstructionSelector::selectMUBUFAddr64(MachineOperand &Root) const {
2663   Register VAddr;
2664   Register RSrcReg;
2665   Register SOffset;
2666   int64_t Offset = 0;
2667 
2668   if (!selectMUBUFAddr64Impl(Root, VAddr, RSrcReg, SOffset, Offset))
2669     return {};
2670 
2671   // FIXME: Use defaulted operands for trailing 0s and remove from the complex
2672   // pattern.
2673   return {{
2674       [=](MachineInstrBuilder &MIB) {  // rsrc
2675         MIB.addReg(RSrcReg);
2676       },
2677       [=](MachineInstrBuilder &MIB) { // vaddr
2678         MIB.addReg(VAddr);
2679       },
2680       [=](MachineInstrBuilder &MIB) { // soffset
2681         if (SOffset)
2682           MIB.addReg(SOffset);
2683         else
2684           MIB.addImm(0);
2685       },
2686       [=](MachineInstrBuilder &MIB) { // offset
2687         MIB.addImm(Offset);
2688       },
2689       addZeroImm, //  glc
2690       addZeroImm, //  slc
2691       addZeroImm, //  tfe
2692       addZeroImm, //  dlc
2693       addZeroImm  //  swz
2694     }};
2695 }
2696 
2697 InstructionSelector::ComplexRendererFns
2698 AMDGPUInstructionSelector::selectMUBUFOffset(MachineOperand &Root) const {
2699   Register RSrcReg;
2700   Register SOffset;
2701   int64_t Offset = 0;
2702 
2703   if (!selectMUBUFOffsetImpl(Root, RSrcReg, SOffset, Offset))
2704     return {};
2705 
2706   return {{
2707       [=](MachineInstrBuilder &MIB) {  // rsrc
2708         MIB.addReg(RSrcReg);
2709       },
2710       [=](MachineInstrBuilder &MIB) { // soffset
2711         if (SOffset)
2712           MIB.addReg(SOffset);
2713         else
2714           MIB.addImm(0);
2715       },
2716       [=](MachineInstrBuilder &MIB) { MIB.addImm(Offset); }, // offset
2717       addZeroImm, //  glc
2718       addZeroImm, //  slc
2719       addZeroImm, //  tfe
2720       addZeroImm, //  dlc
2721       addZeroImm  //  swz
2722     }};
2723 }
2724 
2725 void AMDGPUInstructionSelector::renderTruncImm32(MachineInstrBuilder &MIB,
2726                                                  const MachineInstr &MI,
2727                                                  int OpIdx) const {
2728   assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
2729          "Expected G_CONSTANT");
2730   Optional<int64_t> CstVal = getConstantVRegVal(MI.getOperand(0).getReg(), *MRI);
2731   assert(CstVal && "Expected constant value");
2732   MIB.addImm(CstVal.getValue());
2733 }
2734 
2735 void AMDGPUInstructionSelector::renderNegateImm(MachineInstrBuilder &MIB,
2736                                                 const MachineInstr &MI,
2737                                                 int OpIdx) const {
2738   assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
2739          "Expected G_CONSTANT");
2740   MIB.addImm(-MI.getOperand(1).getCImm()->getSExtValue());
2741 }
2742 
2743 void AMDGPUInstructionSelector::renderBitcastImm(MachineInstrBuilder &MIB,
2744                                                  const MachineInstr &MI,
2745                                                  int OpIdx) const {
2746   assert(OpIdx == -1);
2747 
2748   const MachineOperand &Op = MI.getOperand(1);
2749   if (MI.getOpcode() == TargetOpcode::G_FCONSTANT)
2750     MIB.addImm(Op.getFPImm()->getValueAPF().bitcastToAPInt().getZExtValue());
2751   else {
2752     assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && "Expected G_CONSTANT");
2753     MIB.addImm(Op.getCImm()->getSExtValue());
2754   }
2755 }
2756 
2757 void AMDGPUInstructionSelector::renderPopcntImm(MachineInstrBuilder &MIB,
2758                                                 const MachineInstr &MI,
2759                                                 int OpIdx) const {
2760   assert(MI.getOpcode() == TargetOpcode::G_CONSTANT && OpIdx == -1 &&
2761          "Expected G_CONSTANT");
2762   MIB.addImm(MI.getOperand(1).getCImm()->getValue().countPopulation());
2763 }
2764 
2765 /// This only really exists to satisfy DAG type checking machinery, so is a
2766 /// no-op here.
2767 void AMDGPUInstructionSelector::renderTruncTImm(MachineInstrBuilder &MIB,
2768                                                 const MachineInstr &MI,
2769                                                 int OpIdx) const {
2770   MIB.addImm(MI.getOperand(OpIdx).getImm());
2771 }
2772 
2773 void AMDGPUInstructionSelector::renderExtractGLC(MachineInstrBuilder &MIB,
2774                                                  const MachineInstr &MI,
2775                                                  int OpIdx) const {
2776   assert(OpIdx >= 0 && "expected to match an immediate operand");
2777   MIB.addImm(MI.getOperand(OpIdx).getImm() & 1);
2778 }
2779 
2780 void AMDGPUInstructionSelector::renderExtractSLC(MachineInstrBuilder &MIB,
2781                                                  const MachineInstr &MI,
2782                                                  int OpIdx) const {
2783   assert(OpIdx >= 0 && "expected to match an immediate operand");
2784   MIB.addImm((MI.getOperand(OpIdx).getImm() >> 1) & 1);
2785 }
2786 
2787 void AMDGPUInstructionSelector::renderExtractDLC(MachineInstrBuilder &MIB,
2788                                                  const MachineInstr &MI,
2789                                                  int OpIdx) const {
2790   assert(OpIdx >= 0 && "expected to match an immediate operand");
2791   MIB.addImm((MI.getOperand(OpIdx).getImm() >> 2) & 1);
2792 }
2793 
2794 void AMDGPUInstructionSelector::renderExtractSWZ(MachineInstrBuilder &MIB,
2795                                                  const MachineInstr &MI,
2796                                                  int OpIdx) const {
2797   assert(OpIdx >= 0 && "expected to match an immediate operand");
2798   MIB.addImm((MI.getOperand(OpIdx).getImm() >> 3) & 1);
2799 }
2800 
2801 bool AMDGPUInstructionSelector::isInlineImmediate16(int64_t Imm) const {
2802   return AMDGPU::isInlinableLiteral16(Imm, STI.hasInv2PiInlineImm());
2803 }
2804 
2805 bool AMDGPUInstructionSelector::isInlineImmediate32(int64_t Imm) const {
2806   return AMDGPU::isInlinableLiteral32(Imm, STI.hasInv2PiInlineImm());
2807 }
2808 
2809 bool AMDGPUInstructionSelector::isInlineImmediate64(int64_t Imm) const {
2810   return AMDGPU::isInlinableLiteral64(Imm, STI.hasInv2PiInlineImm());
2811 }
2812 
2813 bool AMDGPUInstructionSelector::isInlineImmediate(const APFloat &Imm) const {
2814   return TII.isInlineConstant(Imm);
2815 }
2816