xref: /freebsd/contrib/llvm-project/llvm/lib/Target/ARM/ARMTargetMachine.cpp (revision a0ca4af9455b844c5e094fc1b09b1390ffa979fc) 
1 //===-- ARMTargetMachine.cpp - Define TargetMachine for ARM ---------------===//
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 "ARMTargetMachine.h"
13 #include "ARM.h"
14 #include "ARMMachineFunctionInfo.h"
15 #include "ARMMacroFusion.h"
16 #include "ARMSubtarget.h"
17 #include "ARMTargetObjectFile.h"
18 #include "ARMTargetTransformInfo.h"
19 #include "MCTargetDesc/ARMMCTargetDesc.h"
20 #include "TargetInfo/ARMTargetInfo.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/ADT/StringRef.h"
23 #include "llvm/Analysis/TargetTransformInfo.h"
24 #include "llvm/CodeGen/ExecutionDomainFix.h"
25 #include "llvm/CodeGen/GlobalISel/CSEInfo.h"
26 #include "llvm/CodeGen/GlobalISel/CallLowering.h"
27 #include "llvm/CodeGen/GlobalISel/IRTranslator.h"
28 #include "llvm/CodeGen/GlobalISel/InstructionSelect.h"
29 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h"
30 #include "llvm/CodeGen/GlobalISel/Legalizer.h"
31 #include "llvm/CodeGen/GlobalISel/LegalizerInfo.h"
32 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h"
33 #include "llvm/CodeGen/MIRParser/MIParser.h"
34 #include "llvm/CodeGen/MachineFunction.h"
35 #include "llvm/CodeGen/MachineScheduler.h"
36 #include "llvm/CodeGen/Passes.h"
37 #include "llvm/CodeGen/RegisterBankInfo.h"
38 #include "llvm/CodeGen/TargetPassConfig.h"
39 #include "llvm/IR/Attributes.h"
40 #include "llvm/IR/DataLayout.h"
41 #include "llvm/IR/Function.h"
42 #include "llvm/MC/TargetRegistry.h"
43 #include "llvm/Pass.h"
44 #include "llvm/Support/CodeGen.h"
45 #include "llvm/Support/CommandLine.h"
46 #include "llvm/Support/ErrorHandling.h"
47 #include "llvm/Target/TargetLoweringObjectFile.h"
48 #include "llvm/Target/TargetOptions.h"
49 #include "llvm/TargetParser/ARMTargetParser.h"
50 #include "llvm/TargetParser/TargetParser.h"
51 #include "llvm/TargetParser/Triple.h"
52 #include "llvm/Transforms/CFGuard.h"
53 #include "llvm/Transforms/IPO.h"
54 #include "llvm/Transforms/Scalar.h"
55 #include <cassert>
56 #include <memory>
57 #include <optional>
58 #include <string>
59 
60 using namespace llvm;
61 
62 static cl::opt<bool>
63 DisableA15SDOptimization("disable-a15-sd-optimization", cl::Hidden,
64                    cl::desc("Inhibit optimization of S->D register accesses on A15"),
65                    cl::init(false));
66 
67 static cl::opt<bool>
68 EnableAtomicTidy("arm-atomic-cfg-tidy", cl::Hidden,
69                  cl::desc("Run SimplifyCFG after expanding atomic operations"
70                           " to make use of cmpxchg flow-based information"),
71                  cl::init(true));
72 
73 static cl::opt<bool>
74 EnableARMLoadStoreOpt("arm-load-store-opt", cl::Hidden,
75                       cl::desc("Enable ARM load/store optimization pass"),
76                       cl::init(true));
77 
78 // FIXME: Unify control over GlobalMerge.
79 static cl::opt<cl::boolOrDefault>
80 EnableGlobalMerge("arm-global-merge", cl::Hidden,
81                   cl::desc("Enable the global merge pass"));
82 
83 namespace llvm {
84   void initializeARMExecutionDomainFixPass(PassRegistry&);
85 }
86 
87 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeARMTarget() {
88   // Register the target.
89   RegisterTargetMachine<ARMLETargetMachine> X(getTheARMLETarget());
90   RegisterTargetMachine<ARMLETargetMachine> A(getTheThumbLETarget());
91   RegisterTargetMachine<ARMBETargetMachine> Y(getTheARMBETarget());
92   RegisterTargetMachine<ARMBETargetMachine> B(getTheThumbBETarget());
93 
94   PassRegistry &Registry = *PassRegistry::getPassRegistry();
95   initializeGlobalISel(Registry);
96   initializeARMLoadStoreOptPass(Registry);
97   initializeARMPreAllocLoadStoreOptPass(Registry);
98   initializeARMParallelDSPPass(Registry);
99   initializeARMBranchTargetsPass(Registry);
100   initializeARMConstantIslandsPass(Registry);
101   initializeARMExecutionDomainFixPass(Registry);
102   initializeARMExpandPseudoPass(Registry);
103   initializeThumb2SizeReducePass(Registry);
104   initializeMVEVPTBlockPass(Registry);
105   initializeMVETPAndVPTOptimisationsPass(Registry);
106   initializeMVETailPredicationPass(Registry);
107   initializeARMLowOverheadLoopsPass(Registry);
108   initializeARMBlockPlacementPass(Registry);
109   initializeMVEGatherScatterLoweringPass(Registry);
110   initializeARMSLSHardeningPass(Registry);
111   initializeMVELaneInterleavingPass(Registry);
112   initializeARMFixCortexA57AES1742098Pass(Registry);
113   initializeARMDAGToDAGISelPass(Registry);
114 }
115 
116 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) {
117   if (TT.isOSBinFormatMachO())
118     return std::make_unique<TargetLoweringObjectFileMachO>();
119   if (TT.isOSWindows())
120     return std::make_unique<TargetLoweringObjectFileCOFF>();
121   return std::make_unique<ARMElfTargetObjectFile>();
122 }
123 
124 static ARMBaseTargetMachine::ARMABI
125 computeTargetABI(const Triple &TT, StringRef CPU,
126                  const TargetOptions &Options) {
127   StringRef ABIName = Options.MCOptions.getABIName();
128 
129   if (ABIName.empty())
130     ABIName = ARM::computeDefaultTargetABI(TT, CPU);
131 
132   if (ABIName == "aapcs16")
133     return ARMBaseTargetMachine::ARM_ABI_AAPCS16;
134   else if (ABIName.starts_with("aapcs"))
135     return ARMBaseTargetMachine::ARM_ABI_AAPCS;
136   else if (ABIName.starts_with("apcs"))
137     return ARMBaseTargetMachine::ARM_ABI_APCS;
138 
139   llvm_unreachable("Unhandled/unknown ABI Name!");
140   return ARMBaseTargetMachine::ARM_ABI_UNKNOWN;
141 }
142 
143 static std::string computeDataLayout(const Triple &TT, StringRef CPU,
144                                      const TargetOptions &Options,
145                                      bool isLittle) {
146   auto ABI = computeTargetABI(TT, CPU, Options);
147   std::string Ret;
148 
149   if (isLittle)
150     // Little endian.
151     Ret += "e";
152   else
153     // Big endian.
154     Ret += "E";
155 
156   Ret += DataLayout::getManglingComponent(TT);
157 
158   // Pointers are 32 bits and aligned to 32 bits.
159   Ret += "-p:32:32";
160 
161   // Function pointers are aligned to 8 bits (because the LSB stores the
162   // ARM/Thumb state).
163   Ret += "-Fi8";
164 
165   // ABIs other than APCS have 64 bit integers with natural alignment.
166   if (ABI != ARMBaseTargetMachine::ARM_ABI_APCS)
167     Ret += "-i64:64";
168 
169   // We have 64 bits floats. The APCS ABI requires them to be aligned to 32
170   // bits, others to 64 bits. We always try to align to 64 bits.
171   if (ABI == ARMBaseTargetMachine::ARM_ABI_APCS)
172     Ret += "-f64:32:64";
173 
174   // We have 128 and 64 bit vectors. The APCS ABI aligns them to 32 bits, others
175   // to 64. We always ty to give them natural alignment.
176   if (ABI == ARMBaseTargetMachine::ARM_ABI_APCS)
177     Ret += "-v64:32:64-v128:32:128";
178   else if (ABI != ARMBaseTargetMachine::ARM_ABI_AAPCS16)
179     Ret += "-v128:64:128";
180 
181   // Try to align aggregates to 32 bits (the default is 64 bits, which has no
182   // particular hardware support on 32-bit ARM).
183   Ret += "-a:0:32";
184 
185   // Integer registers are 32 bits.
186   Ret += "-n32";
187 
188   // The stack is 128 bit aligned on NaCl, 64 bit aligned on AAPCS and 32 bit
189   // aligned everywhere else.
190   if (TT.isOSNaCl() || ABI == ARMBaseTargetMachine::ARM_ABI_AAPCS16)
191     Ret += "-S128";
192   else if (ABI == ARMBaseTargetMachine::ARM_ABI_AAPCS)
193     Ret += "-S64";
194   else
195     Ret += "-S32";
196 
197   return Ret;
198 }
199 
200 static Reloc::Model getEffectiveRelocModel(const Triple &TT,
201                                            std::optional<Reloc::Model> RM) {
202   if (!RM)
203     // Default relocation model on Darwin is PIC.
204     return TT.isOSBinFormatMachO() ? Reloc::PIC_ : Reloc::Static;
205 
206   if (*RM == Reloc::ROPI || *RM == Reloc::RWPI || *RM == Reloc::ROPI_RWPI)
207     assert(TT.isOSBinFormatELF() &&
208            "ROPI/RWPI currently only supported for ELF");
209 
210   // DynamicNoPIC is only used on darwin.
211   if (*RM == Reloc::DynamicNoPIC && !TT.isOSDarwin())
212     return Reloc::Static;
213 
214   return *RM;
215 }
216 
217 /// Create an ARM architecture model.
218 ///
219 ARMBaseTargetMachine::ARMBaseTargetMachine(const Target &T, const Triple &TT,
220                                            StringRef CPU, StringRef FS,
221                                            const TargetOptions &Options,
222                                            std::optional<Reloc::Model> RM,
223                                            std::optional<CodeModel::Model> CM,
224                                            CodeGenOptLevel OL, bool isLittle)
225     : LLVMTargetMachine(T, computeDataLayout(TT, CPU, Options, isLittle), TT,
226                         CPU, FS, Options, getEffectiveRelocModel(TT, RM),
227                         getEffectiveCodeModel(CM, CodeModel::Small), OL),
228       TargetABI(computeTargetABI(TT, CPU, Options)),
229       TLOF(createTLOF(getTargetTriple())), isLittle(isLittle) {
230 
231   // Default to triple-appropriate float ABI
232   if (Options.FloatABIType == FloatABI::Default) {
233     if (isTargetHardFloat())
234       this->Options.FloatABIType = FloatABI::Hard;
235     else
236       this->Options.FloatABIType = FloatABI::Soft;
237   }
238 
239   // Default to triple-appropriate EABI
240   if (Options.EABIVersion == EABI::Default ||
241       Options.EABIVersion == EABI::Unknown) {
242     // musl is compatible with glibc with regard to EABI version
243     if ((TargetTriple.getEnvironment() == Triple::GNUEABI ||
244          TargetTriple.getEnvironment() == Triple::GNUEABIHF ||
245          TargetTriple.getEnvironment() == Triple::MuslEABI ||
246          TargetTriple.getEnvironment() == Triple::MuslEABIHF ||
247          TargetTriple.getEnvironment() == Triple::OpenHOS) &&
248         !(TargetTriple.isOSWindows() || TargetTriple.isOSDarwin()))
249       this->Options.EABIVersion = EABI::GNU;
250     else
251       this->Options.EABIVersion = EABI::EABI5;
252   }
253 
254   if (TT.isOSBinFormatMachO()) {
255     this->Options.TrapUnreachable = true;
256     this->Options.NoTrapAfterNoreturn = true;
257   }
258 
259   // ARM supports the debug entry values.
260   setSupportsDebugEntryValues(true);
261 
262   initAsmInfo();
263 
264   // ARM supports the MachineOutliner.
265   setMachineOutliner(true);
266   setSupportsDefaultOutlining(true);
267 }
268 
269 ARMBaseTargetMachine::~ARMBaseTargetMachine() = default;
270 
271 MachineFunctionInfo *ARMBaseTargetMachine::createMachineFunctionInfo(
272     BumpPtrAllocator &Allocator, const Function &F,
273     const TargetSubtargetInfo *STI) const {
274   return ARMFunctionInfo::create<ARMFunctionInfo>(
275       Allocator, F, static_cast<const ARMSubtarget *>(STI));
276 }
277 
278 const ARMSubtarget *
279 ARMBaseTargetMachine::getSubtargetImpl(const Function &F) const {
280   Attribute CPUAttr = F.getFnAttribute("target-cpu");
281   Attribute FSAttr = F.getFnAttribute("target-features");
282 
283   std::string CPU =
284       CPUAttr.isValid() ? CPUAttr.getValueAsString().str() : TargetCPU;
285   std::string FS =
286       FSAttr.isValid() ? FSAttr.getValueAsString().str() : TargetFS;
287 
288   // FIXME: This is related to the code below to reset the target options,
289   // we need to know whether or not the soft float flag is set on the
290   // function before we can generate a subtarget. We also need to use
291   // it as a key for the subtarget since that can be the only difference
292   // between two functions.
293   bool SoftFloat = F.getFnAttribute("use-soft-float").getValueAsBool();
294   // If the soft float attribute is set on the function turn on the soft float
295   // subtarget feature.
296   if (SoftFloat)
297     FS += FS.empty() ? "+soft-float" : ",+soft-float";
298 
299   // Use the optminsize to identify the subtarget, but don't use it in the
300   // feature string.
301   std::string Key = CPU + FS;
302   if (F.hasMinSize())
303     Key += "+minsize";
304 
305   auto &I = SubtargetMap[Key];
306   if (!I) {
307     // This needs to be done before we create a new subtarget since any
308     // creation will depend on the TM and the code generation flags on the
309     // function that reside in TargetOptions.
310     resetTargetOptions(F);
311     I = std::make_unique<ARMSubtarget>(TargetTriple, CPU, FS, *this, isLittle,
312                                         F.hasMinSize());
313 
314     if (!I->isThumb() && !I->hasARMOps())
315       F.getContext().emitError("Function '" + F.getName() + "' uses ARM "
316           "instructions, but the target does not support ARM mode execution.");
317   }
318 
319   return I.get();
320 }
321 
322 TargetTransformInfo
323 ARMBaseTargetMachine::getTargetTransformInfo(const Function &F) const {
324   return TargetTransformInfo(ARMTTIImpl(this, F));
325 }
326 
327 ARMLETargetMachine::ARMLETargetMachine(const Target &T, const Triple &TT,
328                                        StringRef CPU, StringRef FS,
329                                        const TargetOptions &Options,
330                                        std::optional<Reloc::Model> RM,
331                                        std::optional<CodeModel::Model> CM,
332                                        CodeGenOptLevel OL, bool JIT)
333     : ARMBaseTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, true) {}
334 
335 ARMBETargetMachine::ARMBETargetMachine(const Target &T, const Triple &TT,
336                                        StringRef CPU, StringRef FS,
337                                        const TargetOptions &Options,
338                                        std::optional<Reloc::Model> RM,
339                                        std::optional<CodeModel::Model> CM,
340                                        CodeGenOptLevel OL, bool JIT)
341     : ARMBaseTargetMachine(T, TT, CPU, FS, Options, RM, CM, OL, false) {}
342 
343 namespace {
344 
345 /// ARM Code Generator Pass Configuration Options.
346 class ARMPassConfig : public TargetPassConfig {
347 public:
348   ARMPassConfig(ARMBaseTargetMachine &TM, PassManagerBase &PM)
349       : TargetPassConfig(TM, PM) {}
350 
351   ARMBaseTargetMachine &getARMTargetMachine() const {
352     return getTM<ARMBaseTargetMachine>();
353   }
354 
355   ScheduleDAGInstrs *
356   createMachineScheduler(MachineSchedContext *C) const override {
357     ScheduleDAGMILive *DAG = createGenericSchedLive(C);
358     // add DAG Mutations here.
359     const ARMSubtarget &ST = C->MF->getSubtarget<ARMSubtarget>();
360     if (ST.hasFusion())
361       DAG->addMutation(createARMMacroFusionDAGMutation());
362     return DAG;
363   }
364 
365   ScheduleDAGInstrs *
366   createPostMachineScheduler(MachineSchedContext *C) const override {
367     ScheduleDAGMI *DAG = createGenericSchedPostRA(C);
368     // add DAG Mutations here.
369     const ARMSubtarget &ST = C->MF->getSubtarget<ARMSubtarget>();
370     if (ST.hasFusion())
371       DAG->addMutation(createARMMacroFusionDAGMutation());
372     return DAG;
373   }
374 
375   void addIRPasses() override;
376   void addCodeGenPrepare() override;
377   bool addPreISel() override;
378   bool addInstSelector() override;
379   bool addIRTranslator() override;
380   bool addLegalizeMachineIR() override;
381   bool addRegBankSelect() override;
382   bool addGlobalInstructionSelect() override;
383   void addPreRegAlloc() override;
384   void addPreSched2() override;
385   void addPreEmitPass() override;
386   void addPreEmitPass2() override;
387 
388   std::unique_ptr<CSEConfigBase> getCSEConfig() const override;
389 };
390 
391 class ARMExecutionDomainFix : public ExecutionDomainFix {
392 public:
393   static char ID;
394   ARMExecutionDomainFix() : ExecutionDomainFix(ID, ARM::DPRRegClass) {}
395   StringRef getPassName() const override {
396     return "ARM Execution Domain Fix";
397   }
398 };
399 char ARMExecutionDomainFix::ID;
400 
401 } // end anonymous namespace
402 
403 INITIALIZE_PASS_BEGIN(ARMExecutionDomainFix, "arm-execution-domain-fix",
404   "ARM Execution Domain Fix", false, false)
405 INITIALIZE_PASS_DEPENDENCY(ReachingDefAnalysis)
406 INITIALIZE_PASS_END(ARMExecutionDomainFix, "arm-execution-domain-fix",
407   "ARM Execution Domain Fix", false, false)
408 
409 TargetPassConfig *ARMBaseTargetMachine::createPassConfig(PassManagerBase &PM) {
410   return new ARMPassConfig(*this, PM);
411 }
412 
413 std::unique_ptr<CSEConfigBase> ARMPassConfig::getCSEConfig() const {
414   return getStandardCSEConfigForOpt(TM->getOptLevel());
415 }
416 
417 void ARMPassConfig::addIRPasses() {
418   if (TM->Options.ThreadModel == ThreadModel::Single)
419     addPass(createLowerAtomicPass());
420   else
421     addPass(createAtomicExpandPass());
422 
423   // Cmpxchg instructions are often used with a subsequent comparison to
424   // determine whether it succeeded. We can exploit existing control-flow in
425   // ldrex/strex loops to simplify this, but it needs tidying up.
426   if (TM->getOptLevel() != CodeGenOptLevel::None && EnableAtomicTidy)
427     addPass(createCFGSimplificationPass(
428         SimplifyCFGOptions().hoistCommonInsts(true).sinkCommonInsts(true),
429         [this](const Function &F) {
430           const auto &ST = this->TM->getSubtarget<ARMSubtarget>(F);
431           return ST.hasAnyDataBarrier() && !ST.isThumb1Only();
432         }));
433 
434   addPass(createMVEGatherScatterLoweringPass());
435   addPass(createMVELaneInterleavingPass());
436 
437   TargetPassConfig::addIRPasses();
438 
439   // Run the parallel DSP pass.
440   if (getOptLevel() == CodeGenOptLevel::Aggressive)
441     addPass(createARMParallelDSPPass());
442 
443   // Match complex arithmetic patterns
444   if (TM->getOptLevel() >= CodeGenOptLevel::Default)
445     addPass(createComplexDeinterleavingPass(TM));
446 
447   // Match interleaved memory accesses to ldN/stN intrinsics.
448   if (TM->getOptLevel() != CodeGenOptLevel::None)
449     addPass(createInterleavedAccessPass());
450 
451   // Add Control Flow Guard checks.
452   if (TM->getTargetTriple().isOSWindows())
453     addPass(createCFGuardCheckPass());
454 
455   if (TM->Options.JMCInstrument)
456     addPass(createJMCInstrumenterPass());
457 }
458 
459 void ARMPassConfig::addCodeGenPrepare() {
460   if (getOptLevel() != CodeGenOptLevel::None)
461     addPass(createTypePromotionLegacyPass());
462   TargetPassConfig::addCodeGenPrepare();
463 }
464 
465 bool ARMPassConfig::addPreISel() {
466   if ((TM->getOptLevel() != CodeGenOptLevel::None &&
467        EnableGlobalMerge == cl::BOU_UNSET) ||
468       EnableGlobalMerge == cl::BOU_TRUE) {
469     // FIXME: This is using the thumb1 only constant value for
470     // maximal global offset for merging globals. We may want
471     // to look into using the old value for non-thumb1 code of
472     // 4095 based on the TargetMachine, but this starts to become
473     // tricky when doing code gen per function.
474     bool OnlyOptimizeForSize =
475         (TM->getOptLevel() < CodeGenOptLevel::Aggressive) &&
476         (EnableGlobalMerge == cl::BOU_UNSET);
477     // Merging of extern globals is enabled by default on non-Mach-O as we
478     // expect it to be generally either beneficial or harmless. On Mach-O it
479     // is disabled as we emit the .subsections_via_symbols directive which
480     // means that merging extern globals is not safe.
481     bool MergeExternalByDefault = !TM->getTargetTriple().isOSBinFormatMachO();
482     addPass(createGlobalMergePass(TM, 127, OnlyOptimizeForSize,
483                                   MergeExternalByDefault));
484   }
485 
486   if (TM->getOptLevel() != CodeGenOptLevel::None) {
487     addPass(createHardwareLoopsLegacyPass());
488     addPass(createMVETailPredicationPass());
489     // FIXME: IR passes can delete address-taken basic blocks, deleting
490     // corresponding blockaddresses. ARMConstantPoolConstant holds references to
491     // address-taken basic blocks which can be invalidated if the function
492     // containing the blockaddress has already been codegen'd and the basic
493     // block is removed. Work around this by forcing all IR passes to run before
494     // any ISel takes place. We should have a more principled way of handling
495     // this. See D99707 for more details.
496     addPass(createBarrierNoopPass());
497   }
498 
499   return false;
500 }
501 
502 bool ARMPassConfig::addInstSelector() {
503   addPass(createARMISelDag(getARMTargetMachine(), getOptLevel()));
504   return false;
505 }
506 
507 bool ARMPassConfig::addIRTranslator() {
508   addPass(new IRTranslator(getOptLevel()));
509   return false;
510 }
511 
512 bool ARMPassConfig::addLegalizeMachineIR() {
513   addPass(new Legalizer());
514   return false;
515 }
516 
517 bool ARMPassConfig::addRegBankSelect() {
518   addPass(new RegBankSelect());
519   return false;
520 }
521 
522 bool ARMPassConfig::addGlobalInstructionSelect() {
523   addPass(new InstructionSelect(getOptLevel()));
524   return false;
525 }
526 
527 void ARMPassConfig::addPreRegAlloc() {
528   if (getOptLevel() != CodeGenOptLevel::None) {
529     if (getOptLevel() == CodeGenOptLevel::Aggressive)
530       addPass(&MachinePipelinerID);
531 
532     addPass(createMVETPAndVPTOptimisationsPass());
533 
534     addPass(createMLxExpansionPass());
535 
536     if (EnableARMLoadStoreOpt)
537       addPass(createARMLoadStoreOptimizationPass(/* pre-register alloc */ true));
538 
539     if (!DisableA15SDOptimization)
540       addPass(createA15SDOptimizerPass());
541   }
542 }
543 
544 void ARMPassConfig::addPreSched2() {
545   if (getOptLevel() != CodeGenOptLevel::None) {
546     if (EnableARMLoadStoreOpt)
547       addPass(createARMLoadStoreOptimizationPass());
548 
549     addPass(new ARMExecutionDomainFix());
550     addPass(createBreakFalseDeps());
551   }
552 
553   // Expand some pseudo instructions into multiple instructions to allow
554   // proper scheduling.
555   addPass(createARMExpandPseudoPass());
556 
557   if (getOptLevel() != CodeGenOptLevel::None) {
558     // When optimising for size, always run the Thumb2SizeReduction pass before
559     // IfConversion. Otherwise, check whether IT blocks are restricted
560     // (e.g. in v8, IfConversion depends on Thumb instruction widths)
561     addPass(createThumb2SizeReductionPass([this](const Function &F) {
562       return this->TM->getSubtarget<ARMSubtarget>(F).hasMinSize() ||
563              this->TM->getSubtarget<ARMSubtarget>(F).restrictIT();
564     }));
565 
566     addPass(createIfConverter([](const MachineFunction &MF) {
567       return !MF.getSubtarget<ARMSubtarget>().isThumb1Only();
568     }));
569   }
570   addPass(createThumb2ITBlockPass());
571 
572   // Add both scheduling passes to give the subtarget an opportunity to pick
573   // between them.
574   if (getOptLevel() != CodeGenOptLevel::None) {
575     addPass(&PostMachineSchedulerID);
576     addPass(&PostRASchedulerID);
577   }
578 
579   addPass(createMVEVPTBlockPass());
580   addPass(createARMIndirectThunks());
581   addPass(createARMSLSHardeningPass());
582 }
583 
584 void ARMPassConfig::addPreEmitPass() {
585   addPass(createThumb2SizeReductionPass());
586 
587   // Constant island pass work on unbundled instructions.
588   addPass(createUnpackMachineBundles([](const MachineFunction &MF) {
589     return MF.getSubtarget<ARMSubtarget>().isThumb2();
590   }));
591 
592   // Don't optimize barriers or block placement at -O0.
593   if (getOptLevel() != CodeGenOptLevel::None) {
594     addPass(createARMBlockPlacementPass());
595     addPass(createARMOptimizeBarriersPass());
596   }
597 }
598 
599 void ARMPassConfig::addPreEmitPass2() {
600   // Inserts fixup instructions before unsafe AES operations. Instructions may
601   // be inserted at the start of blocks and at within blocks so this pass has to
602   // come before those below.
603   addPass(createARMFixCortexA57AES1742098Pass());
604   // Inserts BTIs at the start of functions and indirectly-called basic blocks,
605   // so passes cannot add to the start of basic blocks once this has run.
606   addPass(createARMBranchTargetsPass());
607   // Inserts Constant Islands. Block sizes cannot be increased after this point,
608   // as this may push the branch ranges and load offsets of accessing constant
609   // pools out of range..
610   addPass(createARMConstantIslandPass());
611   // Finalises Low-Overhead Loops. This replaces pseudo instructions with real
612   // instructions, but the pseudos all have conservative sizes so that block
613   // sizes will only be decreased by this pass.
614   addPass(createARMLowOverheadLoopsPass());
615 
616   if (TM->getTargetTriple().isOSWindows()) {
617     // Identify valid longjmp targets for Windows Control Flow Guard.
618     addPass(createCFGuardLongjmpPass());
619     // Identify valid eh continuation targets for Windows EHCont Guard.
620     addPass(createEHContGuardCatchretPass());
621   }
622 }
623 
624 yaml::MachineFunctionInfo *
625 ARMBaseTargetMachine::createDefaultFuncInfoYAML() const {
626   return new yaml::ARMFunctionInfo();
627 }
628 
629 yaml::MachineFunctionInfo *
630 ARMBaseTargetMachine::convertFuncInfoToYAML(const MachineFunction &MF) const {
631   const auto *MFI = MF.getInfo<ARMFunctionInfo>();
632   return new yaml::ARMFunctionInfo(*MFI);
633 }
634 
635 bool ARMBaseTargetMachine::parseMachineFunctionInfo(
636     const yaml::MachineFunctionInfo &MFI, PerFunctionMIParsingState &PFS,
637     SMDiagnostic &Error, SMRange &SourceRange) const {
638   const auto &YamlMFI = static_cast<const yaml::ARMFunctionInfo &>(MFI);
639   MachineFunction &MF = PFS.MF;
640   MF.getInfo<ARMFunctionInfo>()->initializeBaseYamlFields(YamlMFI);
641   return false;
642 }
643