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 "AArch64MachineScheduler.h"
16 #include "AArch64MacroFusion.h"
17 #include "AArch64Subtarget.h"
18 #include "AArch64TargetObjectFile.h"
19 #include "AArch64TargetTransformInfo.h"
20 #include "MCTargetDesc/AArch64MCTargetDesc.h"
21 #include "TargetInfo/AArch64TargetInfo.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/ADT/Triple.h"
24 #include "llvm/Analysis/TargetTransformInfo.h"
25 #include "llvm/CodeGen/CFIFixup.h"
26 #include "llvm/CodeGen/CSEConfigBase.h"
27 #include "llvm/CodeGen/GlobalISel/CSEInfo.h"
28 #include "llvm/CodeGen/GlobalISel/IRTranslator.h"
29 #include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
30 #include "llvm/CodeGen/GlobalISel/Legalizer.h"
31 #include "llvm/CodeGen/GlobalISel/LoadStoreOpt.h"
32 #include "llvm/CodeGen/GlobalISel/Localizer.h"
33 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
34 #include "llvm/CodeGen/MIRParser/MIParser.h"
35 #include "llvm/CodeGen/MachineScheduler.h"
36 #include "llvm/CodeGen/Passes.h"
37 #include "llvm/CodeGen/TargetInstrInfo.h"
38 #include "llvm/CodeGen/TargetPassConfig.h"
39 #include "llvm/IR/Attributes.h"
40 #include "llvm/IR/Function.h"
41 #include "llvm/InitializePasses.h"
42 #include "llvm/MC/MCAsmInfo.h"
43 #include "llvm/MC/MCTargetOptions.h"
44 #include "llvm/MC/TargetRegistry.h"
45 #include "llvm/Pass.h"
46 #include "llvm/Support/CodeGen.h"
47 #include "llvm/Support/CommandLine.h"
48 #include "llvm/Target/TargetLoweringObjectFile.h"
49 #include "llvm/Target/TargetOptions.h"
50 #include "llvm/Transforms/CFGuard.h"
51 #include "llvm/Transforms/Scalar.h"
52 #include <memory>
53 #include <string>
54 
55 using namespace llvm;
56 
57 static cl::opt<bool> EnableCCMP("aarch64-enable-ccmp",
58                                 cl::desc("Enable the CCMP formation pass"),
59                                 cl::init(true), cl::Hidden);
60 
61 static cl::opt<bool>
62     EnableCondBrTuning("aarch64-enable-cond-br-tune",
63                        cl::desc("Enable the conditional branch tuning pass"),
64                        cl::init(true), cl::Hidden);
65 
66 static cl::opt<bool> EnableAArch64CopyPropagation(
67     "aarch64-enable-copy-propagation",
68     cl::desc("Enable the copy propagation with AArch64 copy instr"),
69     cl::init(true), cl::Hidden);
70 
71 static cl::opt<bool> EnableMCR("aarch64-enable-mcr",
72                                cl::desc("Enable the machine combiner pass"),
73                                cl::init(true), cl::Hidden);
74 
75 static cl::opt<bool> EnableStPairSuppress("aarch64-enable-stp-suppress",
76                                           cl::desc("Suppress STP for AArch64"),
77                                           cl::init(true), cl::Hidden);
78 
79 static cl::opt<bool> EnableAdvSIMDScalar(
80     "aarch64-enable-simd-scalar",
81     cl::desc("Enable use of AdvSIMD scalar integer instructions"),
82     cl::init(false), cl::Hidden);
83 
84 static cl::opt<bool>
85     EnablePromoteConstant("aarch64-enable-promote-const",
86                           cl::desc("Enable the promote constant pass"),
87                           cl::init(true), cl::Hidden);
88 
89 static cl::opt<bool> EnableCollectLOH(
90     "aarch64-enable-collect-loh",
91     cl::desc("Enable the pass that emits the linker optimization hints (LOH)"),
92     cl::init(true), cl::Hidden);
93 
94 static cl::opt<bool>
95     EnableDeadRegisterElimination("aarch64-enable-dead-defs", cl::Hidden,
96                                   cl::desc("Enable the pass that removes dead"
97                                            " definitons and replaces stores to"
98                                            " them with stores to the zero"
99                                            " register"),
100                                   cl::init(true));
101 
102 static cl::opt<bool> EnableRedundantCopyElimination(
103     "aarch64-enable-copyelim",
104     cl::desc("Enable the redundant copy elimination pass"), cl::init(true),
105     cl::Hidden);
106 
107 static cl::opt<bool> EnableLoadStoreOpt("aarch64-enable-ldst-opt",
108                                         cl::desc("Enable the load/store pair"
109                                                  " optimization pass"),
110                                         cl::init(true), cl::Hidden);
111 
112 static cl::opt<bool> EnableAtomicTidy(
113     "aarch64-enable-atomic-cfg-tidy", cl::Hidden,
114     cl::desc("Run SimplifyCFG after expanding atomic operations"
115              " to make use of cmpxchg flow-based information"),
116     cl::init(true));
117 
118 static cl::opt<bool>
119 EnableEarlyIfConversion("aarch64-enable-early-ifcvt", cl::Hidden,
120                         cl::desc("Run early if-conversion"),
121                         cl::init(true));
122 
123 static cl::opt<bool>
124     EnableCondOpt("aarch64-enable-condopt",
125                   cl::desc("Enable the condition optimizer pass"),
126                   cl::init(true), cl::Hidden);
127 
128 static cl::opt<bool>
129     EnableGEPOpt("aarch64-enable-gep-opt", cl::Hidden,
130                  cl::desc("Enable optimizations on complex GEPs"),
131                  cl::init(true));
132 
133 static cl::opt<bool>
134     BranchRelaxation("aarch64-enable-branch-relax", cl::Hidden, cl::init(true),
135                      cl::desc("Relax out of range conditional branches"));
136 
137 static cl::opt<bool> EnableCompressJumpTables(
138     "aarch64-enable-compress-jump-tables", cl::Hidden, cl::init(true),
139     cl::desc("Use smallest entry possible for jump tables"));
140 
141 // FIXME: Unify control over GlobalMerge.
142 static cl::opt<cl::boolOrDefault>
143     EnableGlobalMerge("aarch64-enable-global-merge", cl::Hidden,
144                       cl::desc("Enable the global merge pass"));
145 
146 static cl::opt<bool>
147     EnableLoopDataPrefetch("aarch64-enable-loop-data-prefetch", cl::Hidden,
148                            cl::desc("Enable the loop data prefetch pass"),
149                            cl::init(true));
150 
151 static cl::opt<int> EnableGlobalISelAtO(
152     "aarch64-enable-global-isel-at-O", cl::Hidden,
153     cl::desc("Enable GlobalISel at or below an opt level (-1 to disable)"),
154     cl::init(0));
155 
156 static cl::opt<bool>
157     EnableSVEIntrinsicOpts("aarch64-enable-sve-intrinsic-opts", cl::Hidden,
158                            cl::desc("Enable SVE intrinsic opts"),
159                            cl::init(true));
160 
161 static cl::opt<bool> EnableFalkorHWPFFix("aarch64-enable-falkor-hwpf-fix",
162                                          cl::init(true), cl::Hidden);
163 
164 static cl::opt<bool>
165     EnableBranchTargets("aarch64-enable-branch-targets", cl::Hidden,
166                         cl::desc("Enable the AArch64 branch target pass"),
167                         cl::init(true));
168 
169 static cl::opt<unsigned> SVEVectorBitsMaxOpt(
170     "aarch64-sve-vector-bits-max",
171     cl::desc("Assume SVE vector registers are at most this big, "
172              "with zero meaning no maximum size is assumed."),
173     cl::init(0), cl::Hidden);
174 
175 static cl::opt<unsigned> SVEVectorBitsMinOpt(
176     "aarch64-sve-vector-bits-min",
177     cl::desc("Assume SVE vector registers are at least this big, "
178              "with zero meaning no minimum size is assumed."),
179     cl::init(0), cl::Hidden);
180 
181 extern cl::opt<bool> EnableHomogeneousPrologEpilog;
182 
183 static cl::opt<bool> EnableGISelLoadStoreOptPreLegal(
184     "aarch64-enable-gisel-ldst-prelegal",
185     cl::desc("Enable GlobalISel's pre-legalizer load/store optimization pass"),
186     cl::init(true), cl::Hidden);
187 
188 static cl::opt<bool> EnableGISelLoadStoreOptPostLegal(
189     "aarch64-enable-gisel-ldst-postlegal",
190     cl::desc("Enable GlobalISel's post-legalizer load/store optimization pass"),
191     cl::init(false), cl::Hidden);
192 
193 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeAArch64Target() {
194   // Register the target.
195   RegisterTargetMachine<AArch64leTargetMachine> X(getTheAArch64leTarget());
196   RegisterTargetMachine<AArch64beTargetMachine> Y(getTheAArch64beTarget());
197   RegisterTargetMachine<AArch64leTargetMachine> Z(getTheARM64Target());
198   RegisterTargetMachine<AArch64leTargetMachine> W(getTheARM64_32Target());
199   RegisterTargetMachine<AArch64leTargetMachine> V(getTheAArch64_32Target());
200   auto PR = PassRegistry::getPassRegistry();
201   initializeGlobalISel(*PR);
202   initializeAArch64A53Fix835769Pass(*PR);
203   initializeAArch64A57FPLoadBalancingPass(*PR);
204   initializeAArch64AdvSIMDScalarPass(*PR);
205   initializeAArch64BranchTargetsPass(*PR);
206   initializeAArch64CollectLOHPass(*PR);
207   initializeAArch64CompressJumpTablesPass(*PR);
208   initializeAArch64ConditionalComparesPass(*PR);
209   initializeAArch64ConditionOptimizerPass(*PR);
210   initializeAArch64DeadRegisterDefinitionsPass(*PR);
211   initializeAArch64ExpandPseudoPass(*PR);
212   initializeAArch64LoadStoreOptPass(*PR);
213   initializeAArch64MIPeepholeOptPass(*PR);
214   initializeAArch64SIMDInstrOptPass(*PR);
215   initializeAArch64O0PreLegalizerCombinerPass(*PR);
216   initializeAArch64PreLegalizerCombinerPass(*PR);
217   initializeAArch64PostLegalizerCombinerPass(*PR);
218   initializeAArch64PostLegalizerLoweringPass(*PR);
219   initializeAArch64PostSelectOptimizePass(*PR);
220   initializeAArch64PromoteConstantPass(*PR);
221   initializeAArch64RedundantCopyEliminationPass(*PR);
222   initializeAArch64StorePairSuppressPass(*PR);
223   initializeFalkorHWPFFixPass(*PR);
224   initializeFalkorMarkStridedAccessesLegacyPass(*PR);
225   initializeLDTLSCleanupPass(*PR);
226   initializeSVEIntrinsicOptsPass(*PR);
227   initializeAArch64SpeculationHardeningPass(*PR);
228   initializeAArch64SLSHardeningPass(*PR);
229   initializeAArch64StackTaggingPass(*PR);
230   initializeAArch64StackTaggingPreRAPass(*PR);
231   initializeAArch64LowerHomogeneousPrologEpilogPass(*PR);
232 }
233 
234 //===----------------------------------------------------------------------===//
235 // AArch64 Lowering public interface.
236 //===----------------------------------------------------------------------===//
237 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
238   if (TT.isOSBinFormatMachO())
239     return std::make_unique<AArch64_MachoTargetObjectFile>();
240   if (TT.isOSBinFormatCOFF())
241     return std::make_unique<AArch64_COFFTargetObjectFile>();
242 
243   return std::make_unique<AArch64_ELFTargetObjectFile>();
244 }
245 
246 // Helper function to build a DataLayout string
247 static std::string computeDataLayout(const Triple &TT,
248                                      const MCTargetOptions &Options,
249                                      bool LittleEndian) {
250   if (TT.isOSBinFormatMachO()) {
251     if (TT.getArch() == Triple::aarch64_32)
252       return "e-m:o-p:32:32-i64:64-i128:128-n32:64-S128";
253     return "e-m:o-i64:64-i128:128-n32:64-S128";
254   }
255   if (TT.isOSBinFormatCOFF())
256     return "e-m:w-p:64:64-i32:32-i64:64-i128:128-n32:64-S128";
257   std::string Endian = LittleEndian ? "e" : "E";
258   std::string Ptr32 = TT.getEnvironment() == Triple::GNUILP32 ? "-p:32:32" : "";
259   return Endian + "-m:e" + Ptr32 +
260          "-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128";
261 }
262 
263 static StringRef computeDefaultCPU(const Triple &TT, StringRef CPU) {
264   if (CPU.empty() && TT.isArm64e())
265     return "apple-a12";
266   return CPU;
267 }
268 
269 static Reloc::Model getEffectiveRelocModel(const Triple &TT,
270                                            Optional<Reloc::Model> RM) {
271   // AArch64 Darwin and Windows are always PIC.
272   if (TT.isOSDarwin() || TT.isOSWindows())
273     return Reloc::PIC_;
274   // On ELF platforms the default static relocation model has a smart enough
275   // linker to cope with referencing external symbols defined in a shared
276   // library. Hence DynamicNoPIC doesn't need to be promoted to PIC.
277   if (!RM || *RM == Reloc::DynamicNoPIC)
278     return Reloc::Static;
279   return *RM;
280 }
281 
282 static CodeModel::Model
283 getEffectiveAArch64CodeModel(const Triple &TT, Optional<CodeModel::Model> CM,
284                              bool JIT) {
285   if (CM) {
286     if (*CM != CodeModel::Small && *CM != CodeModel::Tiny &&
287         *CM != CodeModel::Large) {
288       report_fatal_error(
289           "Only small, tiny and large code models are allowed on AArch64");
290     } else if (*CM == CodeModel::Tiny && !TT.isOSBinFormatELF())
291       report_fatal_error("tiny code model is only supported on ELF");
292     return *CM;
293   }
294   // The default MCJIT memory managers make no guarantees about where they can
295   // find an executable page; JITed code needs to be able to refer to globals
296   // no matter how far away they are.
297   // We should set the CodeModel::Small for Windows ARM64 in JIT mode,
298   // since with large code model LLVM generating 4 MOV instructions, and
299   // Windows doesn't support relocating these long branch (4 MOVs).
300   if (JIT && !TT.isOSWindows())
301     return CodeModel::Large;
302   return CodeModel::Small;
303 }
304 
305 /// Create an AArch64 architecture model.
306 ///
307 AArch64TargetMachine::AArch64TargetMachine(const Target &T, const Triple &TT,
308                                            StringRef CPU, StringRef FS,
309                                            const TargetOptions &Options,
310                                            Optional<Reloc::Model> RM,
311                                            Optional<CodeModel::Model> CM,
312                                            CodeGenOpt::Level OL, bool JIT,
313                                            bool LittleEndian)
314     : LLVMTargetMachine(T,
315                         computeDataLayout(TT, Options.MCOptions, LittleEndian),
316                         TT, computeDefaultCPU(TT, CPU), FS, Options,
317                         getEffectiveRelocModel(TT, RM),
318                         getEffectiveAArch64CodeModel(TT, CM, JIT), OL),
319       TLOF(createTLOF(getTargetTriple())), isLittle(LittleEndian) {
320   initAsmInfo();
321 
322   if (TT.isOSBinFormatMachO()) {
323     this->Options.TrapUnreachable = true;
324     this->Options.NoTrapAfterNoreturn = true;
325   }
326 
327   if (getMCAsmInfo()->usesWindowsCFI()) {
328     // Unwinding can get confused if the last instruction in an
329     // exception-handling region (function, funclet, try block, etc.)
330     // is a call.
331     //
332     // FIXME: We could elide the trap if the next instruction would be in
333     // the same region anyway.
334     this->Options.TrapUnreachable = true;
335   }
336 
337   if (this->Options.TLSSize == 0) // default
338     this->Options.TLSSize = 24;
339   if ((getCodeModel() == CodeModel::Small ||
340        getCodeModel() == CodeModel::Kernel) &&
341       this->Options.TLSSize > 32)
342     // for the small (and kernel) code model, the maximum TLS size is 4GiB
343     this->Options.TLSSize = 32;
344   else if (getCodeModel() == CodeModel::Tiny && this->Options.TLSSize > 24)
345     // for the tiny code model, the maximum TLS size is 1MiB (< 16MiB)
346     this->Options.TLSSize = 24;
347 
348   // Enable GlobalISel at or below EnableGlobalISelAt0, unless this is
349   // MachO/CodeModel::Large, which GlobalISel does not support.
350   if (getOptLevel() <= EnableGlobalISelAtO &&
351       TT.getArch() != Triple::aarch64_32 &&
352       TT.getEnvironment() != Triple::GNUILP32 &&
353       !(getCodeModel() == CodeModel::Large && TT.isOSBinFormatMachO())) {
354     setGlobalISel(true);
355     setGlobalISelAbort(GlobalISelAbortMode::Disable);
356   }
357 
358   // AArch64 supports the MachineOutliner.
359   setMachineOutliner(true);
360 
361   // AArch64 supports default outlining behaviour.
362   setSupportsDefaultOutlining(true);
363 
364   // AArch64 supports the debug entry values.
365   setSupportsDebugEntryValues(true);
366 
367   // AArch64 supports fixing up the DWARF unwind information.
368   if (!getMCAsmInfo()->usesWindowsCFI())
369     setCFIFixup(true);
370 }
371 
372 AArch64TargetMachine::~AArch64TargetMachine() = default;
373 
374 const AArch64Subtarget *
375 AArch64TargetMachine::getSubtargetImpl(const Function &F) const {
376   Attribute CPUAttr = F.getFnAttribute("target-cpu");
377   Attribute TuneAttr = F.getFnAttribute("tune-cpu");
378   Attribute FSAttr = F.getFnAttribute("target-features");
379 
380   std::string CPU =
381       CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
382   std::string TuneCPU =
383       TuneAttr.isValid() ? TuneAttr.getValueAsString().str() : CPU;
384   std::string FS =
385       FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
386 
387   SmallString<512> Key;
388 
389   unsigned MinSVEVectorSize = 0;
390   unsigned MaxSVEVectorSize = 0;
391   Attribute VScaleRangeAttr = F.getFnAttribute(Attribute::VScaleRange);
392   if (VScaleRangeAttr.isValid()) {
393     Optional<unsigned> VScaleMax = VScaleRangeAttr.getVScaleRangeMax();
394     MinSVEVectorSize = VScaleRangeAttr.getVScaleRangeMin() * 128;
395     MaxSVEVectorSize = VScaleMax ? *VScaleMax * 128 : 0;
396   } else {
397     MinSVEVectorSize = SVEVectorBitsMinOpt;
398     MaxSVEVectorSize = SVEVectorBitsMaxOpt;
399   }
400 
401   assert(MinSVEVectorSize % 128 == 0 &&
402          "SVE requires vector length in multiples of 128!");
403   assert(MaxSVEVectorSize % 128 == 0 &&
404          "SVE requires vector length in multiples of 128!");
405   assert((MaxSVEVectorSize >= MinSVEVectorSize || MaxSVEVectorSize == 0) &&
406          "Minimum SVE vector size should not be larger than its maximum!");
407 
408   // Sanitize user input in case of no asserts
409   if (MaxSVEVectorSize == 0)
410     MinSVEVectorSize = (MinSVEVectorSize / 128) * 128;
411   else {
412     MinSVEVectorSize =
413         (std::min(MinSVEVectorSize, MaxSVEVectorSize) / 128) * 128;
414     MaxSVEVectorSize =
415         (std::max(MinSVEVectorSize, MaxSVEVectorSize) / 128) * 128;
416   }
417 
418   Key += "SVEMin";
419   Key += std::to_string(MinSVEVectorSize);
420   Key += "SVEMax";
421   Key += std::to_string(MaxSVEVectorSize);
422   Key += CPU;
423   Key += TuneCPU;
424   Key += FS;
425 
426   auto &I = SubtargetMap[Key];
427   if (!I) {
428     // This needs to be done before we create a new subtarget since any
429     // creation will depend on the TM and the code generation flags on the
430     // function that reside in TargetOptions.
431     resetTargetOptions(F);
432     I = std::make_unique<AArch64Subtarget>(TargetTriple, CPU, TuneCPU, FS,
433                                            *this, isLittle, MinSVEVectorSize,
434                                            MaxSVEVectorSize);
435   }
436   return I.get();
437 }
438 
439 void AArch64leTargetMachine::anchor() { }
440 
441 AArch64leTargetMachine::AArch64leTargetMachine(
442     const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
443     const TargetOptions &Options, Optional<Reloc::Model> RM,
444     Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
445     : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, true) {}
446 
447 void AArch64beTargetMachine::anchor() { }
448 
449 AArch64beTargetMachine::AArch64beTargetMachine(
450     const Target &T, const Triple &TT, StringRef CPU, StringRef FS,
451     const TargetOptions &Options, Optional<Reloc::Model> RM,
452     Optional<CodeModel::Model> CM, CodeGenOpt::Level OL, bool JIT)
453     : AArch64TargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, JIT, false) {}
454 
455 namespace {
456 
457 /// AArch64 Code Generator Pass Configuration Options.
458 class AArch64PassConfig : public TargetPassConfig {
459 public:
460   AArch64PassConfig(AArch64TargetMachine &TM, PassManagerBase &PM)
461       : TargetPassConfig(TM, PM) {
462     if (TM.getOptLevel() != CodeGenOpt::None)
463       substitutePass(&PostRASchedulerID, &PostMachineSchedulerID);
464   }
465 
466   AArch64TargetMachine &getAArch64TargetMachine() const {
467     return getTM<AArch64TargetMachine>();
468   }
469 
470   ScheduleDAGInstrs *
471   createMachineScheduler(MachineSchedContext *C) const override {
472     const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
473     ScheduleDAGMILive *DAG = createGenericSchedLive(C);
474     DAG->addMutation(createLoadClusterDAGMutation(DAG->TII, DAG->TRI));
475     DAG->addMutation(createStoreClusterDAGMutation(DAG->TII, DAG->TRI));
476     if (ST.hasFusion())
477       DAG->addMutation(createAArch64MacroFusionDAGMutation());
478     return DAG;
479   }
480 
481   ScheduleDAGInstrs *
482   createPostMachineScheduler(MachineSchedContext *C) const override {
483     const AArch64Subtarget &ST = C->MF->getSubtarget<AArch64Subtarget>();
484     ScheduleDAGMI *DAG =
485         new ScheduleDAGMI(C, std::make_unique<AArch64PostRASchedStrategy>(C),
486                           /* RemoveKillFlags=*/true);
487     if (ST.hasFusion()) {
488       // Run the Macro Fusion after RA again since literals are expanded from
489       // pseudos then (v. addPreSched2()).
490       DAG->addMutation(createAArch64MacroFusionDAGMutation());
491       return DAG;
492     }
493 
494     return DAG;
495   }
496 
497   void addIRPasses()  override;
498   bool addPreISel() override;
499   void addCodeGenPrepare() override;
500   bool addInstSelector() override;
501   bool addIRTranslator() override;
502   void addPreLegalizeMachineIR() override;
503   bool addLegalizeMachineIR() override;
504   void addPreRegBankSelect() override;
505   bool addRegBankSelect() override;
506   void addPreGlobalInstructionSelect() override;
507   bool addGlobalInstructionSelect() override;
508   void addMachineSSAOptimization() override;
509   bool addILPOpts() override;
510   void addPreRegAlloc() override;
511   void addPostRegAlloc() override;
512   void addPreSched2() override;
513   void addPreEmitPass() override;
514   void addPreEmitPass2() override;
515 
516   std::unique_ptr<CSEConfigBase> getCSEConfig() const override;
517 };
518 
519 } // end anonymous namespace
520 
521 TargetTransformInfo
522 AArch64TargetMachine::getTargetTransformInfo(const Function &F) const {
523   return TargetTransformInfo(AArch64TTIImpl(this, F));
524 }
525 
526 TargetPassConfig *AArch64TargetMachine::createPassConfig(PassManagerBase &PM) {
527   return new AArch64PassConfig(*this, PM);
528 }
529 
530 std::unique_ptr<CSEConfigBase> AArch64PassConfig::getCSEConfig() const {
531   return getStandardCSEConfigForOpt(TM->getOptLevel());
532 }
533 
534 void AArch64PassConfig::addIRPasses() {
535   // Always expand atomic operations, we don't deal with atomicrmw or cmpxchg
536   // ourselves.
537   addPass(createAtomicExpandPass());
538 
539   // Expand any SVE vector library calls that we can't code generate directly.
540   if (EnableSVEIntrinsicOpts && TM->getOptLevel() == CodeGenOpt::Aggressive)
541     addPass(createSVEIntrinsicOptsPass());
542 
543   // Cmpxchg instructions are often used with a subsequent comparison to
544   // determine whether it succeeded. We can exploit existing control-flow in
545   // ldrex/strex loops to simplify this, but it needs tidying up.
546   if (TM->getOptLevel() != CodeGenOpt::None && EnableAtomicTidy)
547     addPass(createCFGSimplificationPass(SimplifyCFGOptions()
548                                             .forwardSwitchCondToPhi(true)
549                                             .convertSwitchRangeToICmp(true)
550                                             .convertSwitchToLookupTable(true)
551                                             .needCanonicalLoops(false)
552                                             .hoistCommonInsts(true)
553                                             .sinkCommonInsts(true)));
554 
555   // Run LoopDataPrefetch
556   //
557   // Run this before LSR to remove the multiplies involved in computing the
558   // pointer values N iterations ahead.
559   if (TM->getOptLevel() != CodeGenOpt::None) {
560     if (EnableLoopDataPrefetch)
561       addPass(createLoopDataPrefetchPass());
562     if (EnableFalkorHWPFFix)
563       addPass(createFalkorMarkStridedAccessesPass());
564   }
565 
566   if (TM->getOptLevel() == CodeGenOpt::Aggressive && EnableGEPOpt) {
567     // Call SeparateConstOffsetFromGEP pass to extract constants within indices
568     // and lower a GEP with multiple indices to either arithmetic operations or
569     // multiple GEPs with single index.
570     addPass(createSeparateConstOffsetFromGEPPass(true));
571     // Call EarlyCSE pass to find and remove subexpressions in the lowered
572     // result.
573     addPass(createEarlyCSEPass());
574     // Do loop invariant code motion in case part of the lowered result is
575     // invariant.
576     addPass(createLICMPass());
577   }
578 
579   TargetPassConfig::addIRPasses();
580 
581   addPass(createAArch64StackTaggingPass(
582       /*IsOptNone=*/TM->getOptLevel() == CodeGenOpt::None));
583 
584   // Match interleaved memory accesses to ldN/stN intrinsics.
585   if (TM->getOptLevel() != CodeGenOpt::None) {
586     addPass(createInterleavedLoadCombinePass());
587     addPass(createInterleavedAccessPass());
588   }
589 
590   // Add Control Flow Guard checks.
591   if (TM->getTargetTriple().isOSWindows())
592     addPass(createCFGuardCheckPass());
593 
594   if (TM->Options.JMCInstrument)
595     addPass(createJMCInstrumenterPass());
596 }
597 
598 // Pass Pipeline Configuration
599 bool AArch64PassConfig::addPreISel() {
600   // Run promote constant before global merge, so that the promoted constants
601   // get a chance to be merged
602   if (TM->getOptLevel() != CodeGenOpt::None && EnablePromoteConstant)
603     addPass(createAArch64PromoteConstantPass());
604   // FIXME: On AArch64, this depends on the type.
605   // Basically, the addressable offsets are up to 4095 * Ty.getSizeInBytes().
606   // and the offset has to be a multiple of the related size in bytes.
607   if ((TM->getOptLevel() != CodeGenOpt::None &&
608        EnableGlobalMerge == cl::BOU_UNSET) ||
609       EnableGlobalMerge == cl::BOU_TRUE) {
610     bool OnlyOptimizeForSize = (TM->getOptLevel() < CodeGenOpt::Aggressive) &&
611                                (EnableGlobalMerge == cl::BOU_UNSET);
612 
613     // Merging of extern globals is enabled by default on non-Mach-O as we
614     // expect it to be generally either beneficial or harmless. On Mach-O it
615     // is disabled as we emit the .subsections_via_symbols directive which
616     // means that merging extern globals is not safe.
617     bool MergeExternalByDefault = !TM->getTargetTriple().isOSBinFormatMachO();
618 
619     // FIXME: extern global merging is only enabled when we optimise for size
620     // because there are some regressions with it also enabled for performance.
621     if (!OnlyOptimizeForSize)
622       MergeExternalByDefault = false;
623 
624     addPass(createGlobalMergePass(TM, 4095, OnlyOptimizeForSize,
625                                   MergeExternalByDefault));
626   }
627 
628   return false;
629 }
630 
631 void AArch64PassConfig::addCodeGenPrepare() {
632   if (getOptLevel() != CodeGenOpt::None)
633     addPass(createTypePromotionPass());
634   TargetPassConfig::addCodeGenPrepare();
635 }
636 
637 bool AArch64PassConfig::addInstSelector() {
638   addPass(createAArch64ISelDag(getAArch64TargetMachine(), getOptLevel()));
639 
640   // For ELF, cleanup any local-dynamic TLS accesses (i.e. combine as many
641   // references to _TLS_MODULE_BASE_ as possible.
642   if (TM->getTargetTriple().isOSBinFormatELF() &&
643       getOptLevel() != CodeGenOpt::None)
644     addPass(createAArch64CleanupLocalDynamicTLSPass());
645 
646   return false;
647 }
648 
649 bool AArch64PassConfig::addIRTranslator() {
650   addPass(new IRTranslator(getOptLevel()));
651   return false;
652 }
653 
654 void AArch64PassConfig::addPreLegalizeMachineIR() {
655   if (getOptLevel() == CodeGenOpt::None)
656     addPass(createAArch64O0PreLegalizerCombiner());
657   else {
658     addPass(createAArch64PreLegalizerCombiner());
659     if (EnableGISelLoadStoreOptPreLegal)
660       addPass(new LoadStoreOpt());
661   }
662 }
663 
664 bool AArch64PassConfig::addLegalizeMachineIR() {
665   addPass(new Legalizer());
666   return false;
667 }
668 
669 void AArch64PassConfig::addPreRegBankSelect() {
670   bool IsOptNone = getOptLevel() == CodeGenOpt::None;
671   if (!IsOptNone) {
672     addPass(createAArch64PostLegalizerCombiner(IsOptNone));
673     if (EnableGISelLoadStoreOptPostLegal)
674       addPass(new LoadStoreOpt());
675   }
676   addPass(createAArch64PostLegalizerLowering());
677 }
678 
679 bool AArch64PassConfig::addRegBankSelect() {
680   addPass(new RegBankSelect());
681   return false;
682 }
683 
684 void AArch64PassConfig::addPreGlobalInstructionSelect() {
685   addPass(new Localizer());
686 }
687 
688 bool AArch64PassConfig::addGlobalInstructionSelect() {
689   addPass(new InstructionSelect(getOptLevel()));
690   if (getOptLevel() != CodeGenOpt::None)
691     addPass(createAArch64PostSelectOptimize());
692   return false;
693 }
694 
695 void AArch64PassConfig::addMachineSSAOptimization() {
696   // Run default MachineSSAOptimization first.
697   TargetPassConfig::addMachineSSAOptimization();
698 
699   if (TM->getOptLevel() != CodeGenOpt::None)
700     addPass(createAArch64MIPeepholeOptPass());
701 }
702 
703 bool AArch64PassConfig::addILPOpts() {
704   if (EnableCondOpt)
705     addPass(createAArch64ConditionOptimizerPass());
706   if (EnableCCMP)
707     addPass(createAArch64ConditionalCompares());
708   if (EnableMCR)
709     addPass(&MachineCombinerID);
710   if (EnableCondBrTuning)
711     addPass(createAArch64CondBrTuning());
712   if (EnableEarlyIfConversion)
713     addPass(&EarlyIfConverterID);
714   if (EnableStPairSuppress)
715     addPass(createAArch64StorePairSuppressPass());
716   addPass(createAArch64SIMDInstrOptPass());
717   if (TM->getOptLevel() != CodeGenOpt::None)
718     addPass(createAArch64StackTaggingPreRAPass());
719   return true;
720 }
721 
722 void AArch64PassConfig::addPreRegAlloc() {
723   // Change dead register definitions to refer to the zero register.
724   if (TM->getOptLevel() != CodeGenOpt::None && EnableDeadRegisterElimination)
725     addPass(createAArch64DeadRegisterDefinitions());
726 
727   // Use AdvSIMD scalar instructions whenever profitable.
728   if (TM->getOptLevel() != CodeGenOpt::None && EnableAdvSIMDScalar) {
729     addPass(createAArch64AdvSIMDScalar());
730     // The AdvSIMD pass may produce copies that can be rewritten to
731     // be register coalescer friendly.
732     addPass(&PeepholeOptimizerID);
733   }
734 }
735 
736 void AArch64PassConfig::addPostRegAlloc() {
737   // Remove redundant copy instructions.
738   if (TM->getOptLevel() != CodeGenOpt::None && EnableRedundantCopyElimination)
739     addPass(createAArch64RedundantCopyEliminationPass());
740 
741   if (TM->getOptLevel() != CodeGenOpt::None && usingDefaultRegAlloc())
742     // Improve performance for some FP/SIMD code for A57.
743     addPass(createAArch64A57FPLoadBalancing());
744 }
745 
746 void AArch64PassConfig::addPreSched2() {
747   // Lower homogeneous frame instructions
748   if (EnableHomogeneousPrologEpilog)
749     addPass(createAArch64LowerHomogeneousPrologEpilogPass());
750   // Expand some pseudo instructions to allow proper scheduling.
751   addPass(createAArch64ExpandPseudoPass());
752   // Use load/store pair instructions when possible.
753   if (TM->getOptLevel() != CodeGenOpt::None) {
754     if (EnableLoadStoreOpt)
755       addPass(createAArch64LoadStoreOptimizationPass());
756   }
757 
758   // The AArch64SpeculationHardeningPass destroys dominator tree and natural
759   // loop info, which is needed for the FalkorHWPFFixPass and also later on.
760   // Therefore, run the AArch64SpeculationHardeningPass before the
761   // FalkorHWPFFixPass to avoid recomputing dominator tree and natural loop
762   // info.
763   addPass(createAArch64SpeculationHardeningPass());
764 
765   addPass(createAArch64IndirectThunks());
766   addPass(createAArch64SLSHardeningPass());
767 
768   if (TM->getOptLevel() != CodeGenOpt::None) {
769     if (EnableFalkorHWPFFix)
770       addPass(createFalkorHWPFFixPass());
771   }
772 }
773 
774 void AArch64PassConfig::addPreEmitPass() {
775   // Machine Block Placement might have created new opportunities when run
776   // at O3, where the Tail Duplication Threshold is set to 4 instructions.
777   // Run the load/store optimizer once more.
778   if (TM->getOptLevel() >= CodeGenOpt::Aggressive && EnableLoadStoreOpt)
779     addPass(createAArch64LoadStoreOptimizationPass());
780 
781   if (TM->getOptLevel() >= CodeGenOpt::Aggressive &&
782       EnableAArch64CopyPropagation)
783     addPass(createMachineCopyPropagationPass(true));
784 
785   addPass(createAArch64A53Fix835769());
786 
787   if (EnableBranchTargets)
788     addPass(createAArch64BranchTargetsPass());
789 
790   // Relax conditional branch instructions if they're otherwise out of
791   // range of their destination.
792   if (BranchRelaxation)
793     addPass(&BranchRelaxationPassID);
794 
795   if (TM->getTargetTriple().isOSWindows()) {
796     // Identify valid longjmp targets for Windows Control Flow Guard.
797     addPass(createCFGuardLongjmpPass());
798     // Identify valid eh continuation targets for Windows EHCont Guard.
799     addPass(createEHContGuardCatchretPass());
800   }
801 
802   if (TM->getOptLevel() != CodeGenOpt::None && EnableCompressJumpTables)
803     addPass(createAArch64CompressJumpTablesPass());
804 
805   if (TM->getOptLevel() != CodeGenOpt::None && EnableCollectLOH &&
806       TM->getTargetTriple().isOSBinFormatMachO())
807     addPass(createAArch64CollectLOHPass());
808 }
809 
810 void AArch64PassConfig::addPreEmitPass2() {
811   // SVE bundles move prefixes with destructive operations. BLR_RVMARKER pseudo
812   // instructions are lowered to bundles as well.
813   addPass(createUnpackMachineBundles(nullptr));
814 }
815 
816 yaml::MachineFunctionInfo *
817 AArch64TargetMachine::createDefaultFuncInfoYAML() const {
818   return new yaml::AArch64FunctionInfo();
819 }
820 
821 yaml::MachineFunctionInfo *
822 AArch64TargetMachine::convertFuncInfoToYAML(const MachineFunction &MF) const {
823   const auto *MFI = MF.getInfo<AArch64FunctionInfo>();
824   return new yaml::AArch64FunctionInfo(*MFI);
825 }
826 
827 bool AArch64TargetMachine::parseMachineFunctionInfo(
828     const yaml::MachineFunctionInfo &MFI, PerFunctionMIParsingState &PFS,
829     SMDiagnostic &Error, SMRange &SourceRange) const {
830   const auto &YamlMFI = static_cast<const yaml::AArch64FunctionInfo &>(MFI);
831   MachineFunction &MF = PFS.MF;
832   MF.getInfo<AArch64FunctionInfo>()->initializeBaseYamlFields(YamlMFI);
833   return false;
834 }
835