1 //=== lib/CodeGen/GlobalISel/AMDGPURegBankCombiner.cpp ---------------===//
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 //
9 // This pass does combining of machine instructions at the generic MI level,
10 // after register banks are known.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "AMDGPU.h"
15 #include "AMDGPULegalizerInfo.h"
16 #include "AMDGPURegisterBankInfo.h"
17 #include "GCNSubtarget.h"
18 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
19 #include "SIMachineFunctionInfo.h"
20 #include "llvm/CodeGen/GlobalISel/Combiner.h"
21 #include "llvm/CodeGen/GlobalISel/CombinerHelper.h"
22 #include "llvm/CodeGen/GlobalISel/CombinerInfo.h"
23 #include "llvm/CodeGen/GlobalISel/GISelKnownBits.h"
24 #include "llvm/CodeGen/GlobalISel/MIPatternMatch.h"
25 #include "llvm/CodeGen/MachineDominators.h"
26 #include "llvm/CodeGen/TargetPassConfig.h"
27 #include "llvm/IR/IntrinsicsAMDGPU.h"
28 #include "llvm/Target/TargetMachine.h"
29 #define DEBUG_TYPE "amdgpu-regbank-combiner"
30 
31 using namespace llvm;
32 using namespace MIPatternMatch;
33 
34 class AMDGPURegBankCombinerHelper {
35 protected:
36   MachineIRBuilder &B;
37   MachineFunction &MF;
38   MachineRegisterInfo &MRI;
39   const GCNSubtarget &Subtarget;
40   const RegisterBankInfo &RBI;
41   const TargetRegisterInfo &TRI;
42   const SIInstrInfo &TII;
43   CombinerHelper &Helper;
44 
45 public:
46   AMDGPURegBankCombinerHelper(MachineIRBuilder &B, CombinerHelper &Helper)
47       : B(B), MF(B.getMF()), MRI(*B.getMRI()),
48         Subtarget(MF.getSubtarget<GCNSubtarget>()),
49         RBI(*Subtarget.getRegBankInfo()), TRI(*Subtarget.getRegisterInfo()),
50         TII(*Subtarget.getInstrInfo()), Helper(Helper){};
51 
52   bool isVgprRegBank(Register Reg);
53   Register getAsVgpr(Register Reg);
54 
55   struct MinMaxMedOpc {
56     unsigned Min, Max, Med;
57   };
58 
59   struct Med3MatchInfo {
60     unsigned Opc;
61     Register Val0, Val1, Val2;
62   };
63 
64   MinMaxMedOpc getMinMaxPair(unsigned Opc);
65 
66   template <class m_Cst, typename CstTy>
67   bool matchMed(MachineInstr &MI, MachineRegisterInfo &MRI, MinMaxMedOpc MMMOpc,
68                 Register &Val, CstTy &K0, CstTy &K1);
69 
70   bool matchIntMinMaxToMed3(MachineInstr &MI, Med3MatchInfo &MatchInfo);
71   bool matchFPMinMaxToMed3(MachineInstr &MI, Med3MatchInfo &MatchInfo);
72   bool matchFPMinMaxToClamp(MachineInstr &MI, Register &Reg);
73   bool matchFPMed3ToClamp(MachineInstr &MI, Register &Reg);
74   void applyMed3(MachineInstr &MI, Med3MatchInfo &MatchInfo);
75   void applyClamp(MachineInstr &MI, Register &Reg);
76 
77 private:
78   AMDGPU::SIModeRegisterDefaults getMode();
79   bool getIEEE();
80   bool getDX10Clamp();
81   bool isFminnumIeee(const MachineInstr &MI);
82   bool isFCst(MachineInstr *MI);
83   bool isClampZeroToOne(MachineInstr *K0, MachineInstr *K1);
84 };
85 
86 bool AMDGPURegBankCombinerHelper::isVgprRegBank(Register Reg) {
87   return RBI.getRegBank(Reg, MRI, TRI)->getID() == AMDGPU::VGPRRegBankID;
88 }
89 
90 Register AMDGPURegBankCombinerHelper::getAsVgpr(Register Reg) {
91   if (isVgprRegBank(Reg))
92     return Reg;
93 
94   // Search for existing copy of Reg to vgpr.
95   for (MachineInstr &Use : MRI.use_instructions(Reg)) {
96     Register Def = Use.getOperand(0).getReg();
97     if (Use.getOpcode() == AMDGPU::COPY && isVgprRegBank(Def))
98       return Def;
99   }
100 
101   // Copy Reg to vgpr.
102   Register VgprReg = B.buildCopy(MRI.getType(Reg), Reg).getReg(0);
103   MRI.setRegBank(VgprReg, RBI.getRegBank(AMDGPU::VGPRRegBankID));
104   return VgprReg;
105 }
106 
107 AMDGPURegBankCombinerHelper::MinMaxMedOpc
108 AMDGPURegBankCombinerHelper::getMinMaxPair(unsigned Opc) {
109   switch (Opc) {
110   default:
111     llvm_unreachable("Unsupported opcode");
112   case AMDGPU::G_SMAX:
113   case AMDGPU::G_SMIN:
114     return {AMDGPU::G_SMIN, AMDGPU::G_SMAX, AMDGPU::G_AMDGPU_SMED3};
115   case AMDGPU::G_UMAX:
116   case AMDGPU::G_UMIN:
117     return {AMDGPU::G_UMIN, AMDGPU::G_UMAX, AMDGPU::G_AMDGPU_UMED3};
118   case AMDGPU::G_FMAXNUM:
119   case AMDGPU::G_FMINNUM:
120     return {AMDGPU::G_FMINNUM, AMDGPU::G_FMAXNUM, AMDGPU::G_AMDGPU_FMED3};
121   case AMDGPU::G_FMAXNUM_IEEE:
122   case AMDGPU::G_FMINNUM_IEEE:
123     return {AMDGPU::G_FMINNUM_IEEE, AMDGPU::G_FMAXNUM_IEEE,
124             AMDGPU::G_AMDGPU_FMED3};
125   }
126 }
127 
128 template <class m_Cst, typename CstTy>
129 bool AMDGPURegBankCombinerHelper::matchMed(MachineInstr &MI,
130                                            MachineRegisterInfo &MRI,
131                                            MinMaxMedOpc MMMOpc, Register &Val,
132                                            CstTy &K0, CstTy &K1) {
133   // 4 operand commutes of: min(max(Val, K0), K1).
134   // Find K1 from outer instr: min(max(...), K1) or min(K1, max(...)).
135   // Find K0 and Val from inner instr: max(K0, Val) or max(Val, K0).
136   // 4 operand commutes of: max(min(Val, K1), K0).
137   // Find K0 from outer instr: max(min(...), K0) or max(K0, min(...)).
138   // Find K1 and Val from inner instr: min(K1, Val) or min(Val, K1).
139   return mi_match(
140       MI, MRI,
141       m_any_of(
142           m_CommutativeBinOp(
143               MMMOpc.Min, m_CommutativeBinOp(MMMOpc.Max, m_Reg(Val), m_Cst(K0)),
144               m_Cst(K1)),
145           m_CommutativeBinOp(
146               MMMOpc.Max, m_CommutativeBinOp(MMMOpc.Min, m_Reg(Val), m_Cst(K1)),
147               m_Cst(K0))));
148 }
149 
150 bool AMDGPURegBankCombinerHelper::matchIntMinMaxToMed3(
151     MachineInstr &MI, Med3MatchInfo &MatchInfo) {
152   Register Dst = MI.getOperand(0).getReg();
153   if (!isVgprRegBank(Dst))
154     return false;
155 
156   // med3 for i16 is only available on gfx9+, and not available for v2i16.
157   LLT Ty = MRI.getType(Dst);
158   if ((Ty != LLT::scalar(16) || !Subtarget.hasMed3_16()) &&
159       Ty != LLT::scalar(32))
160     return false;
161 
162   MinMaxMedOpc OpcodeTriple = getMinMaxPair(MI.getOpcode());
163   Register Val;
164   Optional<ValueAndVReg> K0, K1;
165   // Match min(max(Val, K0), K1) or max(min(Val, K1), K0). Then see if K0 <= K1.
166   if (!matchMed<GCstAndRegMatch>(MI, MRI, OpcodeTriple, Val, K0, K1))
167     return false;
168 
169   if (OpcodeTriple.Med == AMDGPU::G_AMDGPU_SMED3 && K0->Value.sgt(K1->Value))
170     return false;
171   if (OpcodeTriple.Med == AMDGPU::G_AMDGPU_UMED3 && K0->Value.ugt(K1->Value))
172     return false;
173 
174   MatchInfo = {OpcodeTriple.Med, Val, K0->VReg, K1->VReg};
175   return true;
176 }
177 
178 // fmed3(NaN, K0, K1) = min(min(NaN, K0), K1)
179 // ieee = true  : min/max(SNaN, K) = QNaN, min/max(QNaN, K) = K
180 // ieee = false : min/max(NaN, K) = K
181 // clamp(NaN) = dx10_clamp ? 0.0 : NaN
182 // Consider values of min(max(Val, K0), K1) and max(min(Val, K1), K0) as input.
183 // Other operand commutes (see matchMed) give same result since min and max are
184 // commutative.
185 
186 // Try to replace fp min(max(Val, K0), K1) or max(min(Val, K1), K0), KO<=K1
187 // with fmed3(Val, K0, K1) or clamp(Val). Clamp requires K0 = 0.0 and K1 = 1.0.
188 // Val = SNaN only for ieee = true
189 // fmed3(SNaN, K0, K1) = min(min(SNaN, K0), K1) = min(QNaN, K1) = K1
190 // min(max(SNaN, K0), K1) = min(QNaN, K1) = K1
191 // max(min(SNaN, K1), K0) = max(K1, K0) = K1
192 // Val = NaN,ieee = false or Val = QNaN,ieee = true
193 // fmed3(NaN, K0, K1) = min(min(NaN, K0), K1) = min(K0, K1) = K0
194 // min(max(NaN, K0), K1) = min(K0, K1) = K0 (can clamp when dx10_clamp = true)
195 // max(min(NaN, K1), K0) = max(K1, K0) = K1 != K0
196 bool AMDGPURegBankCombinerHelper::matchFPMinMaxToMed3(
197     MachineInstr &MI, Med3MatchInfo &MatchInfo) {
198   Register Dst = MI.getOperand(0).getReg();
199   LLT Ty = MRI.getType(Dst);
200 
201   // med3 for f16 is only available on gfx9+, and not available for v2f16.
202   if ((Ty != LLT::scalar(16) || !Subtarget.hasMed3_16()) &&
203       Ty != LLT::scalar(32))
204     return false;
205 
206   auto OpcodeTriple = getMinMaxPair(MI.getOpcode());
207 
208   Register Val;
209   Optional<FPValueAndVReg> K0, K1;
210   // Match min(max(Val, K0), K1) or max(min(Val, K1), K0). Then see if K0 <= K1.
211   if (!matchMed<GFCstAndRegMatch>(MI, MRI, OpcodeTriple, Val, K0, K1))
212     return false;
213 
214   if (K0->Value > K1->Value)
215     return false;
216 
217   // For IEEE=false perform combine only when it's safe to assume that there are
218   // no NaN inputs. Most often MI is marked with nnan fast math flag.
219   // For IEEE=true consider NaN inputs. fmed3(NaN, K0, K1) is equivalent to
220   // min(min(NaN, K0), K1). Safe to fold for min(max(Val, K0), K1) since inner
221   // nodes(max/min) have same behavior when one input is NaN and other isn't.
222   // Don't consider max(min(SNaN, K1), K0) since there is no isKnownNeverQNaN,
223   // also post-legalizer inputs to min/max are fcanonicalized (never SNaN).
224   if ((getIEEE() && isFminnumIeee(MI)) || isKnownNeverNaN(Dst, MRI)) {
225     // Don't fold single use constant that can't be inlined.
226     if ((!MRI.hasOneNonDBGUse(K0->VReg) || TII.isInlineConstant(K0->Value)) &&
227         (!MRI.hasOneNonDBGUse(K1->VReg) || TII.isInlineConstant(K1->Value))) {
228       MatchInfo = {OpcodeTriple.Med, Val, K0->VReg, K1->VReg};
229       return true;
230     }
231   }
232 
233   return false;
234 }
235 
236 bool AMDGPURegBankCombinerHelper::matchFPMinMaxToClamp(MachineInstr &MI,
237                                                        Register &Reg) {
238   // Clamp is available on all types after regbankselect (f16, f32, f64, v2f16).
239   auto OpcodeTriple = getMinMaxPair(MI.getOpcode());
240   Register Val;
241   Optional<FPValueAndVReg> K0, K1;
242   // Match min(max(Val, K0), K1) or max(min(Val, K1), K0).
243   if (!matchMed<GFCstOrSplatGFCstMatch>(MI, MRI, OpcodeTriple, Val, K0, K1))
244     return false;
245 
246   if (!K0->Value.isExactlyValue(0.0) || !K1->Value.isExactlyValue(1.0))
247     return false;
248 
249   // For IEEE=false perform combine only when it's safe to assume that there are
250   // no NaN inputs. Most often MI is marked with nnan fast math flag.
251   // For IEEE=true consider NaN inputs. Only min(max(QNaN, 0.0), 1.0) evaluates
252   // to 0.0 requires dx10_clamp = true.
253   if ((getIEEE() && getDX10Clamp() && isFminnumIeee(MI) &&
254        isKnownNeverSNaN(Val, MRI)) ||
255       isKnownNeverNaN(MI.getOperand(0).getReg(), MRI)) {
256     Reg = Val;
257     return true;
258   }
259 
260   return false;
261 }
262 
263 // Replacing fmed3(NaN, 0.0, 1.0) with clamp. Requires dx10_clamp = true.
264 // Val = SNaN only for ieee = true. It is important which operand is NaN.
265 // min(min(SNaN, 0.0), 1.0) = min(QNaN, 1.0) = 1.0
266 // min(min(SNaN, 1.0), 0.0) = min(QNaN, 0.0) = 0.0
267 // min(min(0.0, 1.0), SNaN) = min(0.0, SNaN) = QNaN
268 // Val = NaN,ieee = false or Val = QNaN,ieee = true
269 // min(min(NaN, 0.0), 1.0) = min(0.0, 1.0) = 0.0
270 // min(min(NaN, 1.0), 0.0) = min(1.0, 0.0) = 0.0
271 // min(min(0.0, 1.0), NaN) = min(0.0, NaN) = 0.0
272 bool AMDGPURegBankCombinerHelper::matchFPMed3ToClamp(MachineInstr &MI,
273                                                      Register &Reg) {
274   if (MI.getIntrinsicID() != Intrinsic::amdgcn_fmed3)
275     return false;
276 
277   // In llvm-ir, clamp is often represented as an intrinsic call to
278   // @llvm.amdgcn.fmed3.f32(%Val, 0.0, 1.0). Check for other operand orders.
279   MachineInstr *Src0 = getDefIgnoringCopies(MI.getOperand(2).getReg(), MRI);
280   MachineInstr *Src1 = getDefIgnoringCopies(MI.getOperand(3).getReg(), MRI);
281   MachineInstr *Src2 = getDefIgnoringCopies(MI.getOperand(4).getReg(), MRI);
282 
283   if (isFCst(Src0) && !isFCst(Src1))
284     std::swap(Src0, Src1);
285   if (isFCst(Src1) && !isFCst(Src2))
286     std::swap(Src1, Src2);
287   if (isFCst(Src0) && !isFCst(Src1))
288     std::swap(Src0, Src1);
289   if (!isClampZeroToOne(Src1, Src2))
290     return false;
291 
292   Register Val = Src0->getOperand(0).getReg();
293 
294   auto isOp3Zero = [&]() {
295     MachineInstr *Op3 = getDefIgnoringCopies(MI.getOperand(4).getReg(), MRI);
296     if (Op3->getOpcode() == TargetOpcode::G_FCONSTANT)
297       return Op3->getOperand(1).getFPImm()->isExactlyValue(0.0);
298     return false;
299   };
300   // For IEEE=false perform combine only when it's safe to assume that there are
301   // no NaN inputs. Most often MI is marked with nnan fast math flag.
302   // For IEEE=true consider NaN inputs. Requires dx10_clamp = true. Safe to fold
303   // when Val could be QNaN. If Val can also be SNaN third input should be 0.0.
304   if (isKnownNeverNaN(MI.getOperand(0).getReg(), MRI) ||
305       (getIEEE() && getDX10Clamp() &&
306        (isKnownNeverSNaN(Val, MRI) || isOp3Zero()))) {
307     Reg = Val;
308     return true;
309   }
310 
311   return false;
312 }
313 
314 void AMDGPURegBankCombinerHelper::applyClamp(MachineInstr &MI, Register &Reg) {
315   B.setInstrAndDebugLoc(MI);
316   B.buildInstr(AMDGPU::G_AMDGPU_CLAMP, {MI.getOperand(0)}, {Reg},
317                MI.getFlags());
318   MI.eraseFromParent();
319 }
320 
321 void AMDGPURegBankCombinerHelper::applyMed3(MachineInstr &MI,
322                                             Med3MatchInfo &MatchInfo) {
323   B.setInstrAndDebugLoc(MI);
324   B.buildInstr(MatchInfo.Opc, {MI.getOperand(0)},
325                {getAsVgpr(MatchInfo.Val0), getAsVgpr(MatchInfo.Val1),
326                 getAsVgpr(MatchInfo.Val2)},
327                MI.getFlags());
328   MI.eraseFromParent();
329 }
330 
331 AMDGPU::SIModeRegisterDefaults AMDGPURegBankCombinerHelper::getMode() {
332   return MF.getInfo<SIMachineFunctionInfo>()->getMode();
333 }
334 
335 bool AMDGPURegBankCombinerHelper::getIEEE() { return getMode().IEEE; }
336 
337 bool AMDGPURegBankCombinerHelper::getDX10Clamp() { return getMode().DX10Clamp; }
338 
339 bool AMDGPURegBankCombinerHelper::isFminnumIeee(const MachineInstr &MI) {
340   return MI.getOpcode() == AMDGPU::G_FMINNUM_IEEE;
341 }
342 
343 bool AMDGPURegBankCombinerHelper::isFCst(MachineInstr *MI) {
344   return MI->getOpcode() == AMDGPU::G_FCONSTANT;
345 }
346 
347 bool AMDGPURegBankCombinerHelper::isClampZeroToOne(MachineInstr *K0,
348                                                    MachineInstr *K1) {
349   if (isFCst(K0) && isFCst(K1)) {
350     const ConstantFP *KO_FPImm = K0->getOperand(1).getFPImm();
351     const ConstantFP *K1_FPImm = K1->getOperand(1).getFPImm();
352     return (KO_FPImm->isExactlyValue(0.0) && K1_FPImm->isExactlyValue(1.0)) ||
353            (KO_FPImm->isExactlyValue(1.0) && K1_FPImm->isExactlyValue(0.0));
354   }
355   return false;
356 }
357 
358 class AMDGPURegBankCombinerHelperState {
359 protected:
360   CombinerHelper &Helper;
361   AMDGPURegBankCombinerHelper &RegBankHelper;
362 
363 public:
364   AMDGPURegBankCombinerHelperState(CombinerHelper &Helper,
365                                    AMDGPURegBankCombinerHelper &RegBankHelper)
366       : Helper(Helper), RegBankHelper(RegBankHelper) {}
367 };
368 
369 #define AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_DEPS
370 #include "AMDGPUGenRegBankGICombiner.inc"
371 #undef AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_DEPS
372 
373 namespace {
374 #define AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_H
375 #include "AMDGPUGenRegBankGICombiner.inc"
376 #undef AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_H
377 
378 class AMDGPURegBankCombinerInfo final : public CombinerInfo {
379   GISelKnownBits *KB;
380   MachineDominatorTree *MDT;
381 
382 public:
383   AMDGPUGenRegBankCombinerHelperRuleConfig GeneratedRuleCfg;
384 
385   AMDGPURegBankCombinerInfo(bool EnableOpt, bool OptSize, bool MinSize,
386                                   const AMDGPULegalizerInfo *LI,
387                                   GISelKnownBits *KB, MachineDominatorTree *MDT)
388       : CombinerInfo(/*AllowIllegalOps*/ false, /*ShouldLegalizeIllegal*/ true,
389                      /*LegalizerInfo*/ LI, EnableOpt, OptSize, MinSize),
390         KB(KB), MDT(MDT) {
391     if (!GeneratedRuleCfg.parseCommandLineOption())
392       report_fatal_error("Invalid rule identifier");
393   }
394 
395   bool combine(GISelChangeObserver &Observer, MachineInstr &MI,
396                MachineIRBuilder &B) const override;
397 };
398 
399 bool AMDGPURegBankCombinerInfo::combine(GISelChangeObserver &Observer,
400                                               MachineInstr &MI,
401                                               MachineIRBuilder &B) const {
402   CombinerHelper Helper(Observer, B, KB, MDT);
403   AMDGPURegBankCombinerHelper RegBankHelper(B, Helper);
404   AMDGPUGenRegBankCombinerHelper Generated(GeneratedRuleCfg, Helper,
405                                            RegBankHelper);
406 
407   if (Generated.tryCombineAll(Observer, MI, B))
408     return true;
409 
410   return false;
411 }
412 
413 #define AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_CPP
414 #include "AMDGPUGenRegBankGICombiner.inc"
415 #undef AMDGPUREGBANKCOMBINERHELPER_GENCOMBINERHELPER_CPP
416 
417 // Pass boilerplate
418 // ================
419 
420 class AMDGPURegBankCombiner : public MachineFunctionPass {
421 public:
422   static char ID;
423 
424   AMDGPURegBankCombiner(bool IsOptNone = false);
425 
426   StringRef getPassName() const override {
427     return "AMDGPURegBankCombiner";
428   }
429 
430   bool runOnMachineFunction(MachineFunction &MF) override;
431 
432   void getAnalysisUsage(AnalysisUsage &AU) const override;
433 private:
434   bool IsOptNone;
435 };
436 } // end anonymous namespace
437 
438 void AMDGPURegBankCombiner::getAnalysisUsage(AnalysisUsage &AU) const {
439   AU.addRequired<TargetPassConfig>();
440   AU.setPreservesCFG();
441   getSelectionDAGFallbackAnalysisUsage(AU);
442   AU.addRequired<GISelKnownBitsAnalysis>();
443   AU.addPreserved<GISelKnownBitsAnalysis>();
444   if (!IsOptNone) {
445     AU.addRequired<MachineDominatorTree>();
446     AU.addPreserved<MachineDominatorTree>();
447   }
448   MachineFunctionPass::getAnalysisUsage(AU);
449 }
450 
451 AMDGPURegBankCombiner::AMDGPURegBankCombiner(bool IsOptNone)
452   : MachineFunctionPass(ID), IsOptNone(IsOptNone) {
453   initializeAMDGPURegBankCombinerPass(*PassRegistry::getPassRegistry());
454 }
455 
456 bool AMDGPURegBankCombiner::runOnMachineFunction(MachineFunction &MF) {
457   if (MF.getProperties().hasProperty(
458           MachineFunctionProperties::Property::FailedISel))
459     return false;
460   auto *TPC = &getAnalysis<TargetPassConfig>();
461   const Function &F = MF.getFunction();
462   bool EnableOpt =
463       MF.getTarget().getOptLevel() != CodeGenOpt::None && !skipFunction(F);
464 
465   const GCNSubtarget &ST = MF.getSubtarget<GCNSubtarget>();
466   const AMDGPULegalizerInfo *LI
467     = static_cast<const AMDGPULegalizerInfo *>(ST.getLegalizerInfo());
468 
469   GISelKnownBits *KB = &getAnalysis<GISelKnownBitsAnalysis>().get(MF);
470   MachineDominatorTree *MDT =
471       IsOptNone ? nullptr : &getAnalysis<MachineDominatorTree>();
472   AMDGPURegBankCombinerInfo PCInfo(EnableOpt, F.hasOptSize(),
473                                          F.hasMinSize(), LI, KB, MDT);
474   Combiner C(PCInfo, TPC);
475   return C.combineMachineInstrs(MF, /*CSEInfo*/ nullptr);
476 }
477 
478 char AMDGPURegBankCombiner::ID = 0;
479 INITIALIZE_PASS_BEGIN(AMDGPURegBankCombiner, DEBUG_TYPE,
480                       "Combine AMDGPU machine instrs after regbankselect",
481                       false, false)
482 INITIALIZE_PASS_DEPENDENCY(TargetPassConfig)
483 INITIALIZE_PASS_DEPENDENCY(GISelKnownBitsAnalysis)
484 INITIALIZE_PASS_END(AMDGPURegBankCombiner, DEBUG_TYPE,
485                     "Combine AMDGPU machine instrs after regbankselect", false,
486                     false)
487 
488 namespace llvm {
489 FunctionPass *createAMDGPURegBankCombiner(bool IsOptNone) {
490   return new AMDGPURegBankCombiner(IsOptNone);
491 }
492 } // end namespace llvm
493