1 //===-- AArch64TargetMachine.cpp - Define TargetMachine for AArch64 -------===//
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 //
10 //===----------------------------------------------------------------------===//
11 
12 #include "AArch64TargetMachine.h"
13 #include "AArch64.h"
14 #include "AArch64MachineFunctionInfo.h"
15 #include "AArch64MacroFusion.h"
16 #include "AArch64Subtarget.h"
17 #include "AArch64TargetObjectFile.h"
18 #include "AArch64TargetTransformInfo.h"
19 #include "MCTargetDesc/AArch64MCTargetDesc.h"
20 #include "TargetInfo/AArch64TargetInfo.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/Triple.h"
23 #include "llvm/Analysis/TargetTransformInfo.h"
24 #include "llvm/CodeGen/CSEConfigBase.h"
25 #include "llvm/CodeGen/GlobalISel/IRTranslator.h"
26 #include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
27 #include "llvm/CodeGen/GlobalISel/Legalizer.h"
28 #include "llvm/CodeGen/GlobalISel/LoadStoreOpt.h"
29 #include "llvm/CodeGen/GlobalISel/Localizer.h"
30 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
31 #include "llvm/CodeGen/MIRParser/MIParser.h"
32 #include "llvm/CodeGen/MachineScheduler.h"
33 #include "llvm/CodeGen/Passes.h"
34 #include "llvm/CodeGen/TargetPassConfig.h"
35 #include "llvm/IR/Attributes.h"
36 #include "llvm/IR/Function.h"
37 #include "llvm/InitializePasses.h"
38 #include "llvm/MC/MCAsmInfo.h"
39 #include "llvm/MC/MCTargetOptions.h"
40 #include "llvm/MC/TargetRegistry.h"
41 #include "llvm/Pass.h"
42 #include "llvm/Support/CodeGen.h"
43 #include "llvm/Support/CommandLine.h"
44 #include "llvm/Target/TargetLoweringObjectFile.h"
45 #include "llvm/Target/TargetOptions.h"
46 #include "llvm/Transforms/CFGuard.h"
47 #include "llvm/Transforms/Scalar.h"
48 #include <memory>
49 #include <string>
50 
51 using namespace llvm;
52 
53 static cl::opt<bool> EnableCCMP("aarch64-enable-ccmp",
54                                 cl::desc("Enable the CCMP formation pass"),
55                                 cl::init(true), cl::Hidden);
56 
57 static cl::opt<bool>
58     EnableCondBrTuning("aarch64-enable-cond-br-tune",
59                        cl::desc("Enable the conditional branch tuning pass"),
60                        cl::init(true), cl::Hidden);
61 
62 static cl::opt<bool> EnableMCR("aarch64-enable-mcr",
63                                cl::desc("Enable the machine combiner pass"),
64                                cl::init(true), cl::Hidden);
65 
66 static cl::opt<bool> EnableStPairSuppress("aarch64-enable-stp-suppress",
67                                           cl::desc("Suppress STP for AArch64"),
68                                           cl::init(true), cl::Hidden);
69 
70 static cl::opt<bool> EnableAdvSIMDScalar(
71     "aarch64-enable-simd-scalar",
72     cl::desc("Enable use of AdvSIMD scalar integer instructions"),
73     cl::init(false), cl::Hidden);
74 
75 static cl::opt<bool>
76     EnablePromoteConstant("aarch64-enable-promote-const",
77                           cl::desc("Enable the promote constant pass"),
78                           cl::init(true), cl::Hidden);
79 
80 static cl::opt<bool> EnableCollectLOH(
81     "aarch64-enable-collect-loh",
82     cl::desc("Enable the pass that emits the linker optimization hints (LOH)"),
83     cl::init(true), cl::Hidden);
84 
85 static cl::opt<bool>
86     EnableDeadRegisterElimination("aarch64-enable-dead-defs", cl::Hidden,
87                                   cl::desc("Enable the pass that removes dead"
88                                            " definitons and replaces stores to"
89                                            " them with stores to the zero"
90                                            " register"),
91                                   cl::init(true));
92 
93 static cl::opt<bool> EnableRedundantCopyElimination(
94     "aarch64-enable-copyelim",
95     cl::desc("Enable the redundant copy elimination pass"), cl::init(true),
96     cl::Hidden);
97 
98 static cl::opt<bool> EnableLoadStoreOpt("aarch64-enable-ldst-opt",
99                                         cl::desc("Enable the load/store pair"
100                                                  " optimization pass"),
101                                         cl::init(true), cl::Hidden);
102 
103 static cl::opt<bool> EnableAtomicTidy(
104     "aarch64-enable-atomic-cfg-tidy", cl::Hidden,
105     cl::desc("Run SimplifyCFG after expanding atomic operations"
106              " to make use of cmpxchg flow-based information"),
107     cl::init(true));
108 
109 static cl::opt<bool>
110 EnableEarlyIfConversion("aarch64-enable-early-ifcvt", cl::Hidden,
111                         cl::desc("Run early if-conversion"),
112                         cl::init(true));
113 
114 static cl::opt<bool>
115     EnableCondOpt("aarch64-enable-condopt",
116                   cl::desc("Enable the condition optimizer pass"),
117                   cl::init(true), cl::Hidden);
118 
119 static cl::opt<bool>
120     EnableGEPOpt("aarch64-enable-gep-opt", cl::Hidden,
121                  cl::desc("Enable optimizations on complex GEPs"),
122                  cl::init(false));
123 
124 static cl::opt<bool>
125     BranchRelaxation("aarch64-enable-branch-relax", cl::Hidden, cl::init(true),
126                      cl::desc("Relax out of range conditional branches"));
127 
128 static cl::opt<bool> EnableCompressJumpTables(
129     "aarch64-enable-compress-jump-tables", cl::Hidden, cl::init(true),
130     cl::desc("Use smallest entry possible for jump tables"));
131 
132 // FIXME: Unify control over GlobalMerge.
133 static cl::opt<cl::boolOrDefault>
134     EnableGlobalMerge("aarch64-enable-global-merge", cl::Hidden,
135                       cl::desc("Enable the global merge pass"));
136 
137 static cl::opt<bool>
138     EnableLoopDataPrefetch("aarch64-enable-loop-data-prefetch", cl::Hidden,
139                            cl::desc("Enable the loop data prefetch pass"),
140                            cl::init(true));
141 
142 static cl::opt<int> EnableGlobalISelAtO(
143     "aarch64-enable-global-isel-at-O", cl::Hidden,
144     cl::desc("Enable GlobalISel at or below an opt level (-1 to disable)"),
145     cl::init(0));
146 
147 static cl::opt<bool>
148     EnableSVEIntrinsicOpts("aarch64-enable-sve-intrinsic-opts", cl::Hidden,
149                            cl::desc("Enable SVE intrinsic opts"),
150                            cl::init(true));
151 
152 static cl::opt<bool> EnableFalkorHWPFFix("aarch64-enable-falkor-hwpf-fix",
153                                          cl::init(true), cl::Hidden);
154 
155 static cl::opt<bool>
156     EnableBranchTargets("aarch64-enable-branch-targets", cl::Hidden,
157                         cl::desc("Enable the AArch64 branch target pass"),
158                         cl::init(true));
159 
160 static cl::opt<unsigned> SVEVectorBitsMaxOpt(
161     "aarch64-sve-vector-bits-max",
162     cl::desc("Assume SVE vector registers are at most this big, "
163              "with zero meaning no maximum size is assumed."),
164     cl::init(0), cl::Hidden);
165 
166 static cl::opt<unsigned> SVEVectorBitsMinOpt(
167     "aarch64-sve-vector-bits-min",
168     cl::desc("Assume SVE vector registers are at least this big, "
169              "with zero meaning no minimum size is assumed."),
170     cl::init(0), cl::Hidden);
171 
172 extern cl::opt<bool> EnableHomogeneousPrologEpilog;
173 
174 static cl::opt<bool> EnableGISelLoadStoreOptPreLegal(
175     "aarch64-enable-gisel-ldst-prelegal",
176     cl::desc("Enable GlobalISel's pre-legalizer load/store optimization pass"),
177     cl::init(true), cl::Hidden);
178 
179 static cl::opt<bool> EnableGISelLoadStoreOptPostLegal(
180     "aarch64-enable-gisel-ldst-postlegal",
181     cl::desc("Enable GlobalISel's post-legalizer load/store optimization pass"),
182     cl::init(false), cl::Hidden);
183 
184 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Target() {
185   // Register the target.
186   RegisterTargetMachine<AArch64leTargetMachine> X(getTheAArch64leTarget());
187   RegisterTargetMachine<AArch64beTargetMachine> Y(getTheAArch64beTarget());
188   RegisterTargetMachine<AArch64leTargetMachine> Z(getTheARM64Target());
189   RegisterTargetMachine<AArch64leTargetMachine> W(getTheARM64_32Target());
190   RegisterTargetMachine<AArch64leTargetMachine> V(getTheAArch64_32Target());
191   auto PR = PassRegistry::getPassRegistry();
192   initializeGlobalISel(*PR);
193   initializeAArch64A53Fix835769Pass(*PR);
194   initializeAArch64A57FPLoadBalancingPass(*PR);
195   initializeAArch64AdvSIMDScalarPass(*PR);
196   initializeAArch64BranchTargetsPass(*PR);
197   initializeAArch64CollectLOHPass(*PR);
198   initializeAArch64CompressJumpTablesPass(*PR);
199   initializeAArch64ConditionalComparesPass(*PR);
200   initializeAArch64ConditionOptimizerPass(*PR);
201   initializeAArch64DeadRegisterDefinitionsPass(*PR);
202   initializeAArch64ExpandPseudoPass(*PR);
203   initializeAArch64LoadStoreOptPass(*PR);
204   initializeAArch64MIPeepholeOptPass(*PR);
205   initializeAArch64SIMDInstrOptPass(*PR);
206   initializeAArch64O0PreLegalizerCombinerPass(*PR);
207   initializeAArch64PreLegalizerCombinerPass(*PR);
208   initializeAArch64PostLegalizerCombinerPass(*PR);
209   initializeAArch64PostLegalizerLoweringPass(*PR);
210   initializeAArch64PostSelectOptimizePass(*PR);
211   initializeAArch64PromoteConstantPass(*PR);
212   initializeAArch64RedundantCopyEliminationPass(*PR);
213   initializeAArch64StorePairSuppressPass(*PR);
214   initializeFalkorHWPFFixPass(*PR);
215   initializeFalkorMarkStridedAccessesLegacyPass(*PR);
216   initializeLDTLSCleanupPass(*PR);
217   initializeSVEIntrinsicOptsPass(*PR);
218   initializeAArch64SpeculationHardeningPass(*PR);
219   initializeAArch64SLSHardeningPass(*PR);
220   initializeAArch64StackTaggingPass(*PR);
221   initializeAArch64StackTaggingPreRAPass(*PR);
222   initializeAArch64LowerHomogeneousPrologEpilogPass(*PR);
223 }
224 
225 //===----------------------------------------------------------------------===//
226 // AArch64 Lowering public interface.
227 //===----------------------------------------------------------------------===//
228 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
229   if (TT.isOSBinFormatMachO())
230     return std::make_unique<AArch64_MachoTargetObjectFile>();
231   if (TT.isOSBinFormatCOFF())
232     return std::make_unique<AArch64_COFFTargetObjectFile>();
233 
234   return std::make_unique<AArch64_ELFTargetObjectFile>();
235 }
236 
237 // Helper function to build a DataLayout string
238 static std::string computeDataLayout(const Triple &TT,
239                                      const MCTargetOptions &Options,
240                                      bool LittleEndian) {
241   if (TT.isOSBinFormatMachO()) {
242     if (TT.getArch() == Triple::aarch64_32)
243       return "e-m:o-p:32:32-i64:64-i128:128-n32:64-S128";
244     return "e-m:o-i64:64-i128:128-n32:64-S128";
245   }
246   if (TT.isOSBinFormatCOFF())
247     return "e-m:w-p:64:64-i32:32-i64:64-i128:128-n32:64-S128";
248   std::string Endian = LittleEndian ? "e" : "E";
249   std::string Ptr32 = TT.getEnvironment() == Triple::GNUILP32 ? "-p:32:32" : "";
250   return Endian + "-m:e" + Ptr32 +
251          "-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128";
252 }
253 
254 static StringRef computeDefaultCPU(const Triple &TT, StringRef CPU) {
255   if (CPU.empty() && TT.isArm64e())
256     return "apple-a12";
257   return CPU;
258 }
259 
260 static Reloc::Model getEffectiveRelocModel(const Triple &TT,
261                                            Optional<Reloc::Model> RM) {
262   // AArch64 Darwin and Windows are always PIC.
263   if (TT.isOSDarwin() || TT.isOSWindows())
264     return Reloc::PIC_;
265   // On ELF platforms the default static relocation model has a smart enough
266   // linker to cope with referencing external symbols defined in a shared
267   // library. Hence DynamicNoPIC doesn't need to be promoted to PIC.
268   if (!RM.hasValue() || *RM == Reloc::DynamicNoPIC)
269     return Reloc::Static;
270   return *RM;
271 }
272 
273 static CodeModel::Model
274 getEffectiveAArch64CodeModel(const Triple &TT, Optional<CodeModel::Model> CM,
275                              bool JIT) {
276   if (CM) {
277     if (*CM != CodeModel::Small && *CM != CodeModel::Tiny &&
278         *CM != CodeModel::Large) {
279       report_fatal_error(
280           "Only small, tiny and large code models are allowed on AArch64");
281     } else if (*CM == CodeModel::Tiny && !TT.isOSBinFormatELF())
282       report_fatal_error("tiny code model is only supported on ELF");
283     return *CM;
284   }
285   // The default MCJIT memory managers make no guarantees about where they can
286   // find an executable page; JITed code needs to be able to refer to globals
287   // no matter how far away they are.
288   // We should set the CodeModel::Small for Windows ARM64 in JIT mode,
289   // since with large code model LLVM generating 4 MOV instructions, and
290   // Windows doesn't support relocating these long branch (4 MOVs).
291   if (JIT && !TT.isOSWindows())
292     return CodeModel::Large;
293   return CodeModel::Small;
294 }
295 
296 /// Create an AArch64 architecture model.
297 ///
298 AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
299                                            StringRef CPU, StringRef FS,
300                                            const TargetOptions &Options,
301                                            Optional<Reloc::Model> RM,
302                                            Optional<CodeModel::Model> CM,
303                                            CodeGenOpt::Level OL, bool JIT,
304                                            bool LittleEndian)
305     : LLVMTargetMachine(T,
306                         computeDataLayout(TT, Options.MCOptions, LittleEndian),
307                         TT, computeDefaultCPU(TT, CPU), FS, Options,
308                         getEffectiveRelocModel(TT, RM),
309                         getEffectiveAArch64CodeModel(TT, CM, JIT), OL),
310       TLOF(createTLOF(getTargetTriple())), isLittle(LittleEndian) {
311   initAsmInfo();
312 
313   if (TT.isOSBinFormatMachO()) {
314     this->Options.TrapUnreachable = true;
315     this->Options.NoTrapAfterNoreturn = true;
316   }
317 
318   if (getMCAsmInfo()->usesWindowsCFI()) {
319     // Unwinding can get confused if the last instruction in an
320     // exception-handling region (function, funclet, try block, etc.)
321     // is a call.
322     //
323     // FIXME: We could elide the trap if the next instruction would be in
324     // the same region anyway.
325     this->Options.TrapUnreachable = true;
326   }
327 
328   if (this->Options.TLSSize == 0) // default
329     this->Options.TLSSize = 24;
330   if ((getCodeModel() == CodeModel::Small ||
331        getCodeModel() == CodeModel::Kernel) &&
332       this->Options.TLSSize > 32)
333     // for the small (and kernel) code model, the maximum TLS size is 4GiB
334     this->Options.TLSSize = 32;
335   else if (getCodeModel() == CodeModel::Tiny && this->Options.TLSSize > 24)
336     // for the tiny code model, the maximum TLS size is 1MiB (< 16MiB)
337     this->Options.TLSSize = 24;
338 
339   // Enable GlobalISel at or below EnableGlobalISelAt0, unless this is
340   // MachO/CodeModel::Large, which GlobalISel does not support.
341   if (getOptLevel() <= EnableGlobalISelAtO &&
342       TT.getArch() != Triple::aarch64_32 &&
343       TT.getEnvironment() != Triple::GNUILP32 &&
344       !(getCodeModel() == CodeModel::Large && TT.isOSBinFormatMachO())) {
345     setGlobalISel(true);
346     setGlobalISelAbort(GlobalISelAbortMode::Disable);
347   }
348 
349   // AArch64 supports the MachineOutliner.
350   setMachineOutliner(true);
351 
352   // AArch64 supports default outlining behaviour.
353   setSupportsDefaultOutlining(true);
354 
355   // AArch64 supports the debug entry values.
356   setSupportsDebugEntryValues(true);
357 }
358 
359 AArch64TargetMachine::~AArch64TargetMachine() = default;
360 
361 const AArch64Subtarget *
362 AArch64TargetMachine::getSubtargetImpl(const Function &F) const {
363   Attribute CPUAttr = F.getFnAttribute("target-cpu");
364   Attribute TuneAttr = F.getFnAttribute("tune-cpu");
365   Attribute FSAttr = F.getFnAttribute("target-features");
366 
367   std::string CPU =
368       CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
369   std::string TuneCPU =
370       TuneAttr.isValid() ? TuneAttr.getValueAsString().str() : CPU;
371   std::string FS =
372       FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
373 
374   SmallString<512> Key;
375 
376   unsigned MinSVEVectorSize = 0;
377   unsigned MaxSVEVectorSize = 0;
378   Attribute VScaleRangeAttr = F.getFnAttribute(Attribute::VScaleRange);
379   if (VScaleRangeAttr.isValid()) {
380     Optional<unsigned> VScaleMax = VScaleRangeAttr.getVScaleRangeMax();
381     MinSVEVectorSize = VScaleRangeAttr.getVScaleRangeMin() * 128;
382     MaxSVEVectorSize = VScaleMax ? VScaleMax.getValue() * 128 : 0;
383   } else {
384     MinSVEVectorSize = SVEVectorBitsMinOpt;
385     MaxSVEVectorSize = SVEVectorBitsMaxOpt;
386   }
387 
388   assert(MinSVEVectorSize % 128 == 0 &&
389          "SVE requires vector length in multiples of 128!");
390   assert(MaxSVEVectorSize % 128 == 0 &&
391          "SVE requires vector length in multiples of 128!");
392   assert((MaxSVEVectorSize >= MinSVEVectorSize || MaxSVEVectorSize == 0) &&
393          "Minimum SVE vector size should not be larger than its maximum!");
394 
395   // Sanitize user input in case of no asserts
396   if (MaxSVEVectorSize == 0)
397     MinSVEVectorSize = (MinSVEVectorSize / 128) * 128;
398   else {
399     MinSVEVectorSize =
400         (std::min(MinSVEVectorSize, MaxSVEVectorSize) / 128) * 128;
401     MaxSVEVectorSize =
402         (std::max(MinSVEVectorSize, MaxSVEVectorSize) / 128) * 128;
403   }
404 
405   Key += "SVEMin";
406   Key += std::to_string(MinSVEVectorSize);
407   Key += "SVEMax";
408   Key += std::to_string(MaxSVEVectorSize);
409   Key += CPU;
410   Key += TuneCPU;
411   Key += FS;
412 
413   auto &I = SubtargetMap[Key];
414   if (!I) {
415     // This needs to be done before we create a new subtarget since any
416     // creation will depend on the TM and the code generation flags on the
417     // function that reside in TargetOptions.
418     resetTargetOptions(F);
419     I = std::make_unique<AArch64Subtarget>(TargetTriple, CPU, TuneCPU, FS,
420                                            *this, isLittle, MinSVEVectorSize,
421                                            MaxSVEVectorSize);
422   }
423   return I.get();
424 }
425 
426 void AArch64leTargetMachine::anchor() { }
427 
428 AArch64leTargetMachine::AArch64leTargetMachine(
429     const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
430     const TargetOptions &Options, Optional<Reloc::Model> RM,
431     Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
432     : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, true) {}
433 
434 void AArch64beTargetMachine::anchor() { }
435 
436 AArch64beTargetMachine::AArch64beTargetMachine(
437     const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
438     const TargetOptions &Options, Optional<Reloc::Model> RM,
439     Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
440     : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, false) {}
441 
442 namespace {
443 
444 /// AArch64 Code Generator Pass Configuration Options.
445 class AArch64PassConfig : public TargetPassConfig {
446 public:
447   AArch64PassConfig(AArch64TargetMachine &TM, PassManagerBase &PM)
448       : TargetPassConfig(TM, PM) {
449     if (TM.getOptLevel() != CodeGenOpt::None)
450       substitutePass(&PostRASchedulerID, &PostMachineSchedulerID);
451   }
452 
453   AArch64TargetMachine &getAArch64TargetMachine() const {
454     return getTM<AArch64TargetMachine>();
455   }
456 
457   ScheduleDAGInstrs *
458   createMachineScheduler(MachineSchedContext *C) const override {
459     const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
460     ScheduleDAGMILive *DAG = createGenericSchedLive(C);
461     DAG->addMutation(createLoadClusterDAGMutation(DAG->TII, DAG->TRI));
462     DAG->addMutation(createStoreClusterDAGMutation(DAG->TII, DAG->TRI));
463     if (ST.hasFusion())
464       DAG->addMutation(createAArch64MacroFusionDAGMutation());
465     return DAG;
466   }
467 
468   ScheduleDAGInstrs *
469   createPostMachineScheduler(MachineSchedContext *C) const override {
470     const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
471     if (ST.hasFusion()) {
472       // Run the Macro Fusion after RA again since literals are expanded from
473       // pseudos then (v. addPreSched2()).
474       ScheduleDAGMI *DAG = createGenericSchedPostRA(C);
475       DAG->addMutation(createAArch64MacroFusionDAGMutation());
476       return DAG;
477     }
478 
479     return nullptr;
480   }
481 
482   void addIRPasses()  override;
483   bool addPreISel() override;
484   void addCodeGenPrepare() override;
485   bool addInstSelector() override;
486   bool addIRTranslator() override;
487   void addPreLegalizeMachineIR() override;
488   bool addLegalizeMachineIR() override;
489   void addPreRegBankSelect() override;
490   bool addRegBankSelect() override;
491   void addPreGlobalInstructionSelect() override;
492   bool addGlobalInstructionSelect() override;
493   void addMachineSSAOptimization() override;
494   bool addILPOpts() override;
495   void addPreRegAlloc() override;
496   void addPostRegAlloc() override;
497   void addPreSched2() override;
498   void addPreEmitPass() override;
499   void addPreEmitPass2() override;
500 
501   std::unique_ptr<CSEConfigBase> getCSEConfig() const override;
502 };
503 
504 } // end anonymous namespace
505 
506 TargetTransformInfo
507 AArch64TargetMachine::getTargetTransformInfo(const Function &F) {
508   return TargetTransformInfo(AArch64TTIImpl(this, F));
509 }
510 
511 TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
512   return new AArch64PassConfig(*this, PM);
513 }
514 
515 std::unique_ptr<CSEConfigBase> AArch64PassConfig::getCSEConfig() const {
516   return getStandardCSEConfigForOpt(TM->getOptLevel());
517 }
518 
519 void AArch64PassConfig::addIRPasses() {
520   // Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
521   // ourselves.
522   addPass(createAtomicExpandPass());
523 
524   // Expand any SVE vector library calls that we can't code generate directly.
525   if (EnableSVEIntrinsicOpts && TM->getOptLevel() == CodeGenOpt::Aggressive)
526     addPass(createSVEIntrinsicOptsPass());
527 
528   // Cmpxchg instructions are often used with a subsequent comparison to
529   // determine whether it succeeded. We can exploit existing control-flow in
530   // ldrex/strex loops to simplify this, but it needs tidying up.
531   if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
532     addPass(createCFGSimplificationPass(SimplifyCFGOptions()
533                                             .forwardSwitchCondToPhi(true)
534                                             .convertSwitchToLookupTable(true)
535                                             .needCanonicalLoops(false)
536                                             .hoistCommonInsts(true)
537                                             .sinkCommonInsts(true)));
538 
539   // Run LoopDataPrefetch
540   //
541   // Run this before LSR to remove the multiplies involved in computing the
542   // pointer values N iterations ahead.
543   if (TM->getOptLevel() != CodeGenOpt::None) {
544     if (EnableLoopDataPrefetch)
545       addPass(createLoopDataPrefetchPass());
546     if (EnableFalkorHWPFFix)
547       addPass(createFalkorMarkStridedAccessesPass());
548   }
549 
550   TargetPassConfig::addIRPasses();
551 
552   addPass(createAArch64StackTaggingPass(
553       /*IsOptNone=*/TM->getOptLevel() == CodeGenOpt::None));
554 
555   // Match interleaved memory accesses to ldN/stN intrinsics.
556   if (TM->getOptLevel() != CodeGenOpt::None) {
557     addPass(createInterleavedLoadCombinePass());
558     addPass(createInterleavedAccessPass());
559   }
560 
561   if (TM->getOptLevel() == CodeGenOpt::Aggressive && EnableGEPOpt) {
562     // Call SeparateConstOffsetFromGEP pass to extract constants within indices
563     // and lower a GEP with multiple indices to either arithmetic operations or
564     // multiple GEPs with single index.
565     addPass(createSeparateConstOffsetFromGEPPass(true));
566     // Call EarlyCSE pass to find and remove subexpressions in the lowered
567     // result.
568     addPass(createEarlyCSEPass());
569     // Do loop invariant code motion in case part of the lowered result is
570     // invariant.
571     addPass(createLICMPass());
572   }
573 
574   // Add Control Flow Guard checks.
575   if (TM->getTargetTriple().isOSWindows())
576     addPass(createCFGuardCheckPass());
577 
578   if (TM->Options.JMCInstrument)
579     addPass(createJMCInstrumenterPass());
580 }
581 
582 // Pass Pipeline Configuration
583 bool AArch64PassConfig::addPreISel() {
584   // Run promote constant before global merge, so that the promoted constants
585   // get a chance to be merged
586   if (TM->getOptLevel() != CodeGenOpt::None && EnablePromoteConstant)
587     addPass(createAArch64PromoteConstantPass());
588   // FIXME: On AArch64, this depends on the type.
589   // Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
590   // and the offset has to be a multiple of the related size in bytes.
591   if ((TM->getOptLevel() != CodeGenOpt::None &&
592        EnableGlobalMerge == cl::BOU_UNSET) ||
593       EnableGlobalMerge == cl::BOU_TRUE) {
594     bool OnlyOptimizeForSize = (TM->getOptLevel() < CodeGenOpt::Aggressive) &&
595                                (EnableGlobalMerge == cl::BOU_UNSET);
596 
597     // Merging of extern globals is enabled by default on non-Mach-O as we
598     // expect it to be generally either beneficial or harmless. On Mach-O it
599     // is disabled as we emit the .subsections_via_symbols directive which
600     // means that merging extern globals is not safe.
601     bool MergeExternalByDefault = !TM->getTargetTriple().isOSBinFormatMachO();
602 
603     // FIXME: extern global merging is only enabled when we optimise for size
604     // because there are some regressions with it also enabled for performance.
605     if (!OnlyOptimizeForSize)
606       MergeExternalByDefault = false;
607 
608     addPass(createGlobalMergePass(TM, 4095, OnlyOptimizeForSize,
609                                   MergeExternalByDefault));
610   }
611 
612   return false;
613 }
614 
615 void AArch64PassConfig::addCodeGenPrepare() {
616   if (getOptLevel() != CodeGenOpt::None)
617     addPass(createTypePromotionPass());
618   TargetPassConfig::addCodeGenPrepare();
619 }
620 
621 bool AArch64PassConfig::addInstSelector() {
622   addPass(createAArch64ISelDag(getAArch64TargetMachine(), getOptLevel()));
623 
624   // For ELF, cleanup any local-dynamic TLS accesses (i.e. combine as many
625   // references to _TLS_MODULE_BASE_ as possible.
626   if (TM->getTargetTriple().isOSBinFormatELF() &&
627       getOptLevel() != CodeGenOpt::None)
628     addPass(createAArch64CleanupLocalDynamicTLSPass());
629 
630   return false;
631 }
632 
633 bool AArch64PassConfig::addIRTranslator() {
634   addPass(new IRTranslator(getOptLevel()));
635   return false;
636 }
637 
638 void AArch64PassConfig::addPreLegalizeMachineIR() {
639   if (getOptLevel() == CodeGenOpt::None)
640     addPass(createAArch64O0PreLegalizerCombiner());
641   else {
642     addPass(createAArch64PreLegalizerCombiner());
643     if (EnableGISelLoadStoreOptPreLegal)
644       addPass(new LoadStoreOpt());
645   }
646 }
647 
648 bool AArch64PassConfig::addLegalizeMachineIR() {
649   addPass(new Legalizer());
650   return false;
651 }
652 
653 void AArch64PassConfig::addPreRegBankSelect() {
654   bool IsOptNone = getOptLevel() == CodeGenOpt::None;
655   if (!IsOptNone) {
656     addPass(createAArch64PostLegalizerCombiner(IsOptNone));
657     if (EnableGISelLoadStoreOptPostLegal)
658       addPass(new LoadStoreOpt());
659   }
660   addPass(createAArch64PostLegalizerLowering());
661 }
662 
663 bool AArch64PassConfig::addRegBankSelect() {
664   addPass(new RegBankSelect());
665   return false;
666 }
667 
668 void AArch64PassConfig::addPreGlobalInstructionSelect() {
669   addPass(new Localizer());
670 }
671 
672 bool AArch64PassConfig::addGlobalInstructionSelect() {
673   addPass(new InstructionSelect(getOptLevel()));
674   if (getOptLevel() != CodeGenOpt::None)
675     addPass(createAArch64PostSelectOptimize());
676   return false;
677 }
678 
679 void AArch64PassConfig::addMachineSSAOptimization() {
680   // Run default MachineSSAOptimization first.
681   TargetPassConfig::addMachineSSAOptimization();
682 
683   if (TM->getOptLevel() != CodeGenOpt::None)
684     addPass(createAArch64MIPeepholeOptPass());
685 }
686 
687 bool AArch64PassConfig::addILPOpts() {
688   if (EnableCondOpt)
689     addPass(createAArch64ConditionOptimizerPass());
690   if (EnableCCMP)
691     addPass(createAArch64ConditionalCompares());
692   if (EnableMCR)
693     addPass(&MachineCombinerID);
694   if (EnableCondBrTuning)
695     addPass(createAArch64CondBrTuning());
696   if (EnableEarlyIfConversion)
697     addPass(&EarlyIfConverterID);
698   if (EnableStPairSuppress)
699     addPass(createAArch64StorePairSuppressPass());
700   addPass(createAArch64SIMDInstrOptPass());
701   if (TM->getOptLevel() != CodeGenOpt::None)
702     addPass(createAArch64StackTaggingPreRAPass());
703   return true;
704 }
705 
706 void AArch64PassConfig::addPreRegAlloc() {
707   // Change dead register definitions to refer to the zero register.
708   if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
709     addPass(createAArch64DeadRegisterDefinitions());
710 
711   // Use AdvSIMD scalar instructions whenever profitable.
712   if (TM->getOptLevel() != CodeGenOpt::None && EnableAdvSIMDScalar) {
713     addPass(createAArch64AdvSIMDScalar());
714     // The AdvSIMD pass may produce copies that can be rewritten to
715     // be register coalescer friendly.
716     addPass(&PeepholeOptimizerID);
717   }
718 }
719 
720 void AArch64PassConfig::addPostRegAlloc() {
721   // Remove redundant copy instructions.
722   if (TM->getOptLevel() != CodeGenOpt::None && EnableRedundantCopyElimination)
723     addPass(createAArch64RedundantCopyEliminationPass());
724 
725   if (TM->getOptLevel() != CodeGenOpt::None && usingDefaultRegAlloc())
726     // Improve performance for some FP/SIMD code for A57.
727     addPass(createAArch64A57FPLoadBalancing());
728 }
729 
730 void AArch64PassConfig::addPreSched2() {
731   // Lower homogeneous frame instructions
732   if (EnableHomogeneousPrologEpilog)
733     addPass(createAArch64LowerHomogeneousPrologEpilogPass());
734   // Expand some pseudo instructions to allow proper scheduling.
735   addPass(createAArch64ExpandPseudoPass());
736   // Use load/store pair instructions when possible.
737   if (TM->getOptLevel() != CodeGenOpt::None) {
738     if (EnableLoadStoreOpt)
739       addPass(createAArch64LoadStoreOptimizationPass());
740   }
741 
742   // The AArch64SpeculationHardeningPass destroys dominator tree and natural
743   // loop info, which is needed for the FalkorHWPFFixPass and also later on.
744   // Therefore, run the AArch64SpeculationHardeningPass before the
745   // FalkorHWPFFixPass to avoid recomputing dominator tree and natural loop
746   // info.
747   addPass(createAArch64SpeculationHardeningPass());
748 
749   addPass(createAArch64IndirectThunks());
750   addPass(createAArch64SLSHardeningPass());
751 
752   if (TM->getOptLevel() != CodeGenOpt::None) {
753     if (EnableFalkorHWPFFix)
754       addPass(createFalkorHWPFFixPass());
755   }
756 }
757 
758 void AArch64PassConfig::addPreEmitPass() {
759   // Machine Block Placement might have created new opportunities when run
760   // at O3, where the Tail Duplication Threshold is set to 4 instructions.
761   // Run the load/store optimizer once more.
762   if (TM->getOptLevel() >= CodeGenOpt::Aggressive && EnableLoadStoreOpt)
763     addPass(createAArch64LoadStoreOptimizationPass());
764 
765   addPass(createAArch64A53Fix835769());
766 
767   if (EnableBranchTargets)
768     addPass(createAArch64BranchTargetsPass());
769 
770   // Relax conditional branch instructions if they're otherwise out of
771   // range of their destination.
772   if (BranchRelaxation)
773     addPass(&BranchRelaxationPassID);
774 
775   if (TM->getTargetTriple().isOSWindows()) {
776     // Identify valid longjmp targets for Windows Control Flow Guard.
777     addPass(createCFGuardLongjmpPass());
778     // Identify valid eh continuation targets for Windows EHCont Guard.
779     addPass(createEHContGuardCatchretPass());
780   }
781 
782   if (TM->getOptLevel() != CodeGenOpt::None && EnableCompressJumpTables)
783     addPass(createAArch64CompressJumpTablesPass());
784 
785   if (TM->getOptLevel() != CodeGenOpt::None && EnableCollectLOH &&
786       TM->getTargetTriple().isOSBinFormatMachO())
787     addPass(createAArch64CollectLOHPass());
788 }
789 
790 void AArch64PassConfig::addPreEmitPass2() {
791   // SVE bundles move prefixes with destructive operations. BLR_RVMARKER pseudo
792   // instructions are lowered to bundles as well.
793   addPass(createUnpackMachineBundles(nullptr));
794 }
795 
796 yaml::MachineFunctionInfo *
797 AArch64TargetMachine::createDefaultFuncInfoYAML() const {
798   return new yaml::AArch64FunctionInfo();
799 }
800 
801 yaml::MachineFunctionInfo *
802 AArch64TargetMachine::convertFuncInfoToYAML(const MachineFunction &MF) const {
803   const auto *MFI = MF.getInfo<AArch64FunctionInfo>();
804   return new yaml::AArch64FunctionInfo(*MFI);
805 }
806 
807 bool AArch64TargetMachine::parseMachineFunctionInfo(
808     const yaml::MachineFunctionInfo &MFI, PerFunctionMIParsingState &PFS,
809     SMDiagnostic &Error, SMRange &SourceRange) const {
810   const auto &YamlMFI =
811       reinterpret_cast<const yaml::AArch64FunctionInfo &>(MFI);
812   MachineFunction &MF = PFS.MF;
813   MF.getInfo<AArch64FunctionInfo>()->initializeBaseYamlFields(YamlMFI);
814   return false;
815 }
816