1 //===-- X86TargetMachine.cpp - Define TargetMachine for the X86 -----------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines the X86 specific subclass of TargetMachine. 10 // 11 //===----------------------------------------------------------------------===// 12 13 #include "X86TargetMachine.h" 14 #include "MCTargetDesc/X86MCTargetDesc.h" 15 #include "TargetInfo/X86TargetInfo.h" 16 #include "X86.h" 17 #include "X86CallLowering.h" 18 #include "X86LegalizerInfo.h" 19 #include "X86MachineFunctionInfo.h" 20 #include "X86MacroFusion.h" 21 #include "X86Subtarget.h" 22 #include "X86TargetObjectFile.h" 23 #include "X86TargetTransformInfo.h" 24 #include "llvm/ADT/STLExtras.h" 25 #include "llvm/ADT/SmallString.h" 26 #include "llvm/ADT/StringRef.h" 27 #include "llvm/Analysis/TargetTransformInfo.h" 28 #include "llvm/CodeGen/ExecutionDomainFix.h" 29 #include "llvm/CodeGen/GlobalISel/CSEInfo.h" 30 #include "llvm/CodeGen/GlobalISel/CallLowering.h" 31 #include "llvm/CodeGen/GlobalISel/IRTranslator.h" 32 #include "llvm/CodeGen/GlobalISel/InstructionSelect.h" 33 #include "llvm/CodeGen/GlobalISel/InstructionSelector.h" 34 #include "llvm/CodeGen/GlobalISel/Legalizer.h" 35 #include "llvm/CodeGen/GlobalISel/RegBankSelect.h" 36 #include "llvm/CodeGen/MachineScheduler.h" 37 #include "llvm/CodeGen/Passes.h" 38 #include "llvm/CodeGen/RegAllocRegistry.h" 39 #include "llvm/CodeGen/TargetPassConfig.h" 40 #include "llvm/IR/Attributes.h" 41 #include "llvm/IR/DataLayout.h" 42 #include "llvm/IR/Function.h" 43 #include "llvm/MC/MCAsmInfo.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/Support/ErrorHandling.h" 49 #include "llvm/Target/TargetLoweringObjectFile.h" 50 #include "llvm/Target/TargetOptions.h" 51 #include "llvm/TargetParser/Triple.h" 52 #include "llvm/Transforms/CFGuard.h" 53 #include <memory> 54 #include <optional> 55 #include <string> 56 57 using namespace llvm; 58 59 static cl::opt<bool> EnableMachineCombinerPass("x86-machine-combiner", 60 cl::desc("Enable the machine combiner pass"), 61 cl::init(true), cl::Hidden); 62 63 static cl::opt<bool> 64 EnableTileRAPass("x86-tile-ra", 65 cl::desc("Enable the tile register allocation pass"), 66 cl::init(true), cl::Hidden); 67 68 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeX86Target() { 69 // Register the target. 70 RegisterTargetMachine<X86TargetMachine> X(getTheX86_32Target()); 71 RegisterTargetMachine<X86TargetMachine> Y(getTheX86_64Target()); 72 73 PassRegistry &PR = *PassRegistry::getPassRegistry(); 74 initializeX86LowerAMXIntrinsicsLegacyPassPass(PR); 75 initializeX86LowerAMXTypeLegacyPassPass(PR); 76 initializeX86PreAMXConfigPassPass(PR); 77 initializeX86PreTileConfigPass(PR); 78 initializeGlobalISel(PR); 79 initializeWinEHStatePassPass(PR); 80 initializeFixupBWInstPassPass(PR); 81 initializeEvexToVexInstPassPass(PR); 82 initializeFixupLEAPassPass(PR); 83 initializeFPSPass(PR); 84 initializeX86FixupSetCCPassPass(PR); 85 initializeX86CallFrameOptimizationPass(PR); 86 initializeX86CmovConverterPassPass(PR); 87 initializeX86TileConfigPass(PR); 88 initializeX86FastPreTileConfigPass(PR); 89 initializeX86FastTileConfigPass(PR); 90 initializeKCFIPass(PR); 91 initializeX86LowerTileCopyPass(PR); 92 initializeX86ExpandPseudoPass(PR); 93 initializeX86ExecutionDomainFixPass(PR); 94 initializeX86DomainReassignmentPass(PR); 95 initializeX86AvoidSFBPassPass(PR); 96 initializeX86AvoidTrailingCallPassPass(PR); 97 initializeX86SpeculativeLoadHardeningPassPass(PR); 98 initializeX86SpeculativeExecutionSideEffectSuppressionPass(PR); 99 initializeX86FlagsCopyLoweringPassPass(PR); 100 initializeX86LoadValueInjectionLoadHardeningPassPass(PR); 101 initializeX86LoadValueInjectionRetHardeningPassPass(PR); 102 initializeX86OptimizeLEAPassPass(PR); 103 initializeX86PartialReductionPass(PR); 104 initializePseudoProbeInserterPass(PR); 105 initializeX86ReturnThunksPass(PR); 106 initializeX86DAGToDAGISelPass(PR); 107 initializeX86ArgumentStackSlotPassPass(PR); 108 } 109 110 static std::unique_ptr<TargetLoweringObjectFile> createTLOF(const Triple &TT) { 111 if (TT.isOSBinFormatMachO()) { 112 if (TT.getArch() == Triple::x86_64) 113 return std::make_unique<X86_64MachoTargetObjectFile>(); 114 return std::make_unique<TargetLoweringObjectFileMachO>(); 115 } 116 117 if (TT.isOSBinFormatCOFF()) 118 return std::make_unique<TargetLoweringObjectFileCOFF>(); 119 return std::make_unique<X86ELFTargetObjectFile>(); 120 } 121 122 static std::string computeDataLayout(const Triple &TT) { 123 // X86 is little endian 124 std::string Ret = "e"; 125 126 Ret += DataLayout::getManglingComponent(TT); 127 // X86 and x32 have 32 bit pointers. 128 if (!TT.isArch64Bit() || TT.isX32() || TT.isOSNaCl()) 129 Ret += "-p:32:32"; 130 131 // Address spaces for 32 bit signed, 32 bit unsigned, and 64 bit pointers. 132 Ret += "-p270:32:32-p271:32:32-p272:64:64"; 133 134 // Some ABIs align 64 bit integers and doubles to 64 bits, others to 32. 135 if (TT.isArch64Bit() || TT.isOSWindows() || TT.isOSNaCl()) 136 Ret += "-i64:64"; 137 else if (TT.isOSIAMCU()) 138 Ret += "-i64:32-f64:32"; 139 else 140 Ret += "-f64:32:64"; 141 142 // Some ABIs align long double to 128 bits, others to 32. 143 if (TT.isOSNaCl() || TT.isOSIAMCU()) 144 ; // No f80 145 else if (TT.isArch64Bit() || TT.isOSDarwin() || TT.isWindowsMSVCEnvironment()) 146 Ret += "-f80:128"; 147 else 148 Ret += "-f80:32"; 149 150 if (TT.isOSIAMCU()) 151 Ret += "-f128:32"; 152 153 // The registers can hold 8, 16, 32 or, in x86-64, 64 bits. 154 if (TT.isArch64Bit()) 155 Ret += "-n8:16:32:64"; 156 else 157 Ret += "-n8:16:32"; 158 159 // The stack is aligned to 32 bits on some ABIs and 128 bits on others. 160 if ((!TT.isArch64Bit() && TT.isOSWindows()) || TT.isOSIAMCU()) 161 Ret += "-a:0:32-S32"; 162 else 163 Ret += "-S128"; 164 165 return Ret; 166 } 167 168 static Reloc::Model getEffectiveRelocModel(const Triple &TT, bool JIT, 169 std::optional<Reloc::Model> RM) { 170 bool is64Bit = TT.getArch() == Triple::x86_64; 171 if (!RM) { 172 // JIT codegen should use static relocations by default, since it's 173 // typically executed in process and not relocatable. 174 if (JIT) 175 return Reloc::Static; 176 177 // Darwin defaults to PIC in 64 bit mode and dynamic-no-pic in 32 bit mode. 178 // Win64 requires rip-rel addressing, thus we force it to PIC. Otherwise we 179 // use static relocation model by default. 180 if (TT.isOSDarwin()) { 181 if (is64Bit) 182 return Reloc::PIC_; 183 return Reloc::DynamicNoPIC; 184 } 185 if (TT.isOSWindows() && is64Bit) 186 return Reloc::PIC_; 187 return Reloc::Static; 188 } 189 190 // ELF and X86-64 don't have a distinct DynamicNoPIC model. DynamicNoPIC 191 // is defined as a model for code which may be used in static or dynamic 192 // executables but not necessarily a shared library. On X86-32 we just 193 // compile in -static mode, in x86-64 we use PIC. 194 if (*RM == Reloc::DynamicNoPIC) { 195 if (is64Bit) 196 return Reloc::PIC_; 197 if (!TT.isOSDarwin()) 198 return Reloc::Static; 199 } 200 201 // If we are on Darwin, disallow static relocation model in X86-64 mode, since 202 // the Mach-O file format doesn't support it. 203 if (*RM == Reloc::Static && TT.isOSDarwin() && is64Bit) 204 return Reloc::PIC_; 205 206 return *RM; 207 } 208 209 static CodeModel::Model 210 getEffectiveX86CodeModel(std::optional<CodeModel::Model> CM, bool JIT, 211 bool Is64Bit) { 212 if (CM) { 213 if (*CM == CodeModel::Tiny) 214 report_fatal_error("Target does not support the tiny CodeModel", false); 215 return *CM; 216 } 217 if (JIT) 218 return Is64Bit ? CodeModel::Large : CodeModel::Small; 219 return CodeModel::Small; 220 } 221 222 /// Create an X86 target. 223 /// 224 X86TargetMachine::X86TargetMachine(const Target &T, const Triple &TT, 225 StringRef CPU, StringRef FS, 226 const TargetOptions &Options, 227 std::optional<Reloc::Model> RM, 228 std::optional<CodeModel::Model> CM, 229 CodeGenOpt::Level OL, bool JIT) 230 : LLVMTargetMachine( 231 T, computeDataLayout(TT), TT, CPU, FS, Options, 232 getEffectiveRelocModel(TT, JIT, RM), 233 getEffectiveX86CodeModel(CM, JIT, TT.getArch() == Triple::x86_64), 234 OL), 235 TLOF(createTLOF(getTargetTriple())), IsJIT(JIT) { 236 // On PS4/PS5, the "return address" of a 'noreturn' call must still be within 237 // the calling function, and TrapUnreachable is an easy way to get that. 238 if (TT.isPS() || TT.isOSBinFormatMachO()) { 239 this->Options.TrapUnreachable = true; 240 this->Options.NoTrapAfterNoreturn = TT.isOSBinFormatMachO(); 241 } 242 243 setMachineOutliner(true); 244 245 // x86 supports the debug entry values. 246 setSupportsDebugEntryValues(true); 247 248 initAsmInfo(); 249 } 250 251 X86TargetMachine::~X86TargetMachine() = default; 252 253 const X86Subtarget * 254 X86TargetMachine::getSubtargetImpl(const Function &F) const { 255 Attribute CPUAttr = F.getFnAttribute("target-cpu"); 256 Attribute TuneAttr = F.getFnAttribute("tune-cpu"); 257 Attribute FSAttr = F.getFnAttribute("target-features"); 258 259 StringRef CPU = 260 CPUAttr.isValid() ? CPUAttr.getValueAsString() : (StringRef)TargetCPU; 261 // "x86-64" is a default target setting for many front ends. In these cases, 262 // they actually request for "generic" tuning unless the "tune-cpu" was 263 // specified. 264 StringRef TuneCPU = TuneAttr.isValid() ? TuneAttr.getValueAsString() 265 : CPU == "x86-64" ? "generic" 266 : (StringRef)CPU; 267 StringRef FS = 268 FSAttr.isValid() ? FSAttr.getValueAsString() : (StringRef)TargetFS; 269 270 SmallString<512> Key; 271 // The additions here are ordered so that the definitely short strings are 272 // added first so we won't exceed the small size. We append the 273 // much longer FS string at the end so that we only heap allocate at most 274 // one time. 275 276 // Extract prefer-vector-width attribute. 277 unsigned PreferVectorWidthOverride = 0; 278 Attribute PreferVecWidthAttr = F.getFnAttribute("prefer-vector-width"); 279 if (PreferVecWidthAttr.isValid()) { 280 StringRef Val = PreferVecWidthAttr.getValueAsString(); 281 unsigned Width; 282 if (!Val.getAsInteger(0, Width)) { 283 Key += 'p'; 284 Key += Val; 285 PreferVectorWidthOverride = Width; 286 } 287 } 288 289 // Extract min-legal-vector-width attribute. 290 unsigned RequiredVectorWidth = UINT32_MAX; 291 Attribute MinLegalVecWidthAttr = F.getFnAttribute("min-legal-vector-width"); 292 if (MinLegalVecWidthAttr.isValid()) { 293 StringRef Val = MinLegalVecWidthAttr.getValueAsString(); 294 unsigned Width; 295 if (!Val.getAsInteger(0, Width)) { 296 Key += 'm'; 297 Key += Val; 298 RequiredVectorWidth = Width; 299 } 300 } 301 302 // Add CPU to the Key. 303 Key += CPU; 304 305 // Add tune CPU to the Key. 306 Key += TuneCPU; 307 308 // Keep track of the start of the feature portion of the string. 309 unsigned FSStart = Key.size(); 310 311 // FIXME: This is related to the code below to reset the target options, 312 // we need to know whether or not the soft float flag is set on the 313 // function before we can generate a subtarget. We also need to use 314 // it as a key for the subtarget since that can be the only difference 315 // between two functions. 316 bool SoftFloat = F.getFnAttribute("use-soft-float").getValueAsBool(); 317 // If the soft float attribute is set on the function turn on the soft float 318 // subtarget feature. 319 if (SoftFloat) 320 Key += FS.empty() ? "+soft-float" : "+soft-float,"; 321 322 Key += FS; 323 324 // We may have added +soft-float to the features so move the StringRef to 325 // point to the full string in the Key. 326 FS = Key.substr(FSStart); 327 328 auto &I = SubtargetMap[Key]; 329 if (!I) { 330 // This needs to be done before we create a new subtarget since any 331 // creation will depend on the TM and the code generation flags on the 332 // function that reside in TargetOptions. 333 resetTargetOptions(F); 334 I = std::make_unique<X86Subtarget>( 335 TargetTriple, CPU, TuneCPU, FS, *this, 336 MaybeAlign(F.getParent()->getOverrideStackAlignment()), 337 PreferVectorWidthOverride, RequiredVectorWidth); 338 } 339 return I.get(); 340 } 341 342 bool X86TargetMachine::isNoopAddrSpaceCast(unsigned SrcAS, 343 unsigned DestAS) const { 344 assert(SrcAS != DestAS && "Expected different address spaces!"); 345 if (getPointerSize(SrcAS) != getPointerSize(DestAS)) 346 return false; 347 return SrcAS < 256 && DestAS < 256; 348 } 349 350 //===----------------------------------------------------------------------===// 351 // X86 TTI query. 352 //===----------------------------------------------------------------------===// 353 354 TargetTransformInfo 355 X86TargetMachine::getTargetTransformInfo(const Function &F) const { 356 return TargetTransformInfo(X86TTIImpl(this, F)); 357 } 358 359 //===----------------------------------------------------------------------===// 360 // Pass Pipeline Configuration 361 //===----------------------------------------------------------------------===// 362 363 namespace { 364 365 /// X86 Code Generator Pass Configuration Options. 366 class X86PassConfig : public TargetPassConfig { 367 public: 368 X86PassConfig(X86TargetMachine &TM, PassManagerBase &PM) 369 : TargetPassConfig(TM, PM) {} 370 371 X86TargetMachine &getX86TargetMachine() const { 372 return getTM<X86TargetMachine>(); 373 } 374 375 ScheduleDAGInstrs * 376 createMachineScheduler(MachineSchedContext *C) const override { 377 ScheduleDAGMILive *DAG = createGenericSchedLive(C); 378 DAG->addMutation(createX86MacroFusionDAGMutation()); 379 return DAG; 380 } 381 382 ScheduleDAGInstrs * 383 createPostMachineScheduler(MachineSchedContext *C) const override { 384 ScheduleDAGMI *DAG = createGenericSchedPostRA(C); 385 DAG->addMutation(createX86MacroFusionDAGMutation()); 386 return DAG; 387 } 388 389 void addIRPasses() override; 390 bool addInstSelector() override; 391 bool addIRTranslator() override; 392 bool addLegalizeMachineIR() override; 393 bool addRegBankSelect() override; 394 bool addGlobalInstructionSelect() override; 395 bool addILPOpts() override; 396 bool addPreISel() override; 397 void addMachineSSAOptimization() override; 398 void addPreRegAlloc() override; 399 bool addPostFastRegAllocRewrite() override; 400 void addPostRegAlloc() override; 401 void addPreEmitPass() override; 402 void addPreEmitPass2() override; 403 void addPreSched2() override; 404 bool addRegAssignAndRewriteOptimized() override; 405 406 std::unique_ptr<CSEConfigBase> getCSEConfig() const override; 407 }; 408 409 class X86ExecutionDomainFix : public ExecutionDomainFix { 410 public: 411 static char ID; 412 X86ExecutionDomainFix() : ExecutionDomainFix(ID, X86::VR128XRegClass) {} 413 StringRef getPassName() const override { 414 return "X86 Execution Dependency Fix"; 415 } 416 }; 417 char X86ExecutionDomainFix::ID; 418 419 } // end anonymous namespace 420 421 INITIALIZE_PASS_BEGIN(X86ExecutionDomainFix, "x86-execution-domain-fix", 422 "X86 Execution Domain Fix", false, false) 423 INITIALIZE_PASS_DEPENDENCY(ReachingDefAnalysis) 424 INITIALIZE_PASS_END(X86ExecutionDomainFix, "x86-execution-domain-fix", 425 "X86 Execution Domain Fix", false, false) 426 427 TargetPassConfig *X86TargetMachine::createPassConfig(PassManagerBase &PM) { 428 return new X86PassConfig(*this, PM); 429 } 430 431 MachineFunctionInfo *X86TargetMachine::createMachineFunctionInfo( 432 BumpPtrAllocator &Allocator, const Function &F, 433 const TargetSubtargetInfo *STI) const { 434 return X86MachineFunctionInfo::create<X86MachineFunctionInfo>(Allocator, F, 435 STI); 436 } 437 438 void X86PassConfig::addIRPasses() { 439 addPass(createAtomicExpandPass()); 440 441 // We add both pass anyway and when these two passes run, we skip the pass 442 // based on the option level and option attribute. 443 addPass(createX86LowerAMXIntrinsicsPass()); 444 addPass(createX86LowerAMXTypePass()); 445 446 TargetPassConfig::addIRPasses(); 447 448 if (TM->getOptLevel() != CodeGenOpt::None) { 449 addPass(createInterleavedAccessPass()); 450 addPass(createX86PartialReductionPass()); 451 } 452 453 // Add passes that handle indirect branch removal and insertion of a retpoline 454 // thunk. These will be a no-op unless a function subtarget has the retpoline 455 // feature enabled. 456 addPass(createIndirectBrExpandPass()); 457 458 // Add Control Flow Guard checks. 459 const Triple &TT = TM->getTargetTriple(); 460 if (TT.isOSWindows()) { 461 if (TT.getArch() == Triple::x86_64) { 462 addPass(createCFGuardDispatchPass()); 463 } else { 464 addPass(createCFGuardCheckPass()); 465 } 466 } 467 468 if (TM->Options.JMCInstrument) 469 addPass(createJMCInstrumenterPass()); 470 } 471 472 bool X86PassConfig::addInstSelector() { 473 // Install an instruction selector. 474 addPass(createX86ISelDag(getX86TargetMachine(), getOptLevel())); 475 476 // For ELF, cleanup any local-dynamic TLS accesses. 477 if (TM->getTargetTriple().isOSBinFormatELF() && 478 getOptLevel() != CodeGenOpt::None) 479 addPass(createCleanupLocalDynamicTLSPass()); 480 481 addPass(createX86GlobalBaseRegPass()); 482 addPass(createX86ArgumentStackSlotPass()); 483 return false; 484 } 485 486 bool X86PassConfig::addIRTranslator() { 487 addPass(new IRTranslator(getOptLevel())); 488 return false; 489 } 490 491 bool X86PassConfig::addLegalizeMachineIR() { 492 addPass(new Legalizer()); 493 return false; 494 } 495 496 bool X86PassConfig::addRegBankSelect() { 497 addPass(new RegBankSelect()); 498 return false; 499 } 500 501 bool X86PassConfig::addGlobalInstructionSelect() { 502 addPass(new InstructionSelect(getOptLevel())); 503 return false; 504 } 505 506 bool X86PassConfig::addILPOpts() { 507 addPass(&EarlyIfConverterID); 508 if (EnableMachineCombinerPass) 509 addPass(&MachineCombinerID); 510 addPass(createX86CmovConverterPass()); 511 return true; 512 } 513 514 bool X86PassConfig::addPreISel() { 515 // Only add this pass for 32-bit x86 Windows. 516 const Triple &TT = TM->getTargetTriple(); 517 if (TT.isOSWindows() && TT.getArch() == Triple::x86) 518 addPass(createX86WinEHStatePass()); 519 return true; 520 } 521 522 void X86PassConfig::addPreRegAlloc() { 523 if (getOptLevel() != CodeGenOpt::None) { 524 addPass(&LiveRangeShrinkID); 525 addPass(createX86FixupSetCC()); 526 addPass(createX86OptimizeLEAs()); 527 addPass(createX86CallFrameOptimization()); 528 addPass(createX86AvoidStoreForwardingBlocks()); 529 } 530 531 addPass(createX86SpeculativeLoadHardeningPass()); 532 addPass(createX86FlagsCopyLoweringPass()); 533 addPass(createX86DynAllocaExpander()); 534 535 if (getOptLevel() != CodeGenOpt::None) 536 addPass(createX86PreTileConfigPass()); 537 else 538 addPass(createX86FastPreTileConfigPass()); 539 } 540 541 void X86PassConfig::addMachineSSAOptimization() { 542 addPass(createX86DomainReassignmentPass()); 543 TargetPassConfig::addMachineSSAOptimization(); 544 } 545 546 void X86PassConfig::addPostRegAlloc() { 547 addPass(createX86LowerTileCopyPass()); 548 addPass(createX86FloatingPointStackifierPass()); 549 // When -O0 is enabled, the Load Value Injection Hardening pass will fall back 550 // to using the Speculative Execution Side Effect Suppression pass for 551 // mitigation. This is to prevent slow downs due to 552 // analyses needed by the LVIHardening pass when compiling at -O0. 553 if (getOptLevel() != CodeGenOpt::None) 554 addPass(createX86LoadValueInjectionLoadHardeningPass()); 555 } 556 557 void X86PassConfig::addPreSched2() { 558 addPass(createX86ExpandPseudoPass()); 559 addPass(createKCFIPass()); 560 } 561 562 void X86PassConfig::addPreEmitPass() { 563 if (getOptLevel() != CodeGenOpt::None) { 564 addPass(new X86ExecutionDomainFix()); 565 addPass(createBreakFalseDeps()); 566 } 567 568 addPass(createX86IndirectBranchTrackingPass()); 569 570 addPass(createX86IssueVZeroUpperPass()); 571 572 if (getOptLevel() != CodeGenOpt::None) { 573 addPass(createX86FixupBWInsts()); 574 addPass(createX86PadShortFunctions()); 575 addPass(createX86FixupLEAs()); 576 addPass(createX86FixupInstTuning()); 577 addPass(createX86FixupVectorConstants()); 578 } 579 addPass(createX86EvexToVexInsts()); 580 addPass(createX86DiscriminateMemOpsPass()); 581 addPass(createX86InsertPrefetchPass()); 582 addPass(createX86InsertX87waitPass()); 583 } 584 585 void X86PassConfig::addPreEmitPass2() { 586 const Triple &TT = TM->getTargetTriple(); 587 const MCAsmInfo *MAI = TM->getMCAsmInfo(); 588 589 // The X86 Speculative Execution Pass must run after all control 590 // flow graph modifying passes. As a result it was listed to run right before 591 // the X86 Retpoline Thunks pass. The reason it must run after control flow 592 // graph modifications is that the model of LFENCE in LLVM has to be updated 593 // (FIXME: https://bugs.llvm.org/show_bug.cgi?id=45167). Currently the 594 // placement of this pass was hand checked to ensure that the subsequent 595 // passes don't move the code around the LFENCEs in a way that will hurt the 596 // correctness of this pass. This placement has been shown to work based on 597 // hand inspection of the codegen output. 598 addPass(createX86SpeculativeExecutionSideEffectSuppression()); 599 addPass(createX86IndirectThunksPass()); 600 addPass(createX86ReturnThunksPass()); 601 602 // Insert extra int3 instructions after trailing call instructions to avoid 603 // issues in the unwinder. 604 if (TT.isOSWindows() && TT.getArch() == Triple::x86_64) 605 addPass(createX86AvoidTrailingCallPass()); 606 607 // Verify basic block incoming and outgoing cfa offset and register values and 608 // correct CFA calculation rule where needed by inserting appropriate CFI 609 // instructions. 610 if (!TT.isOSDarwin() && 611 (!TT.isOSWindows() || 612 MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI)) 613 addPass(createCFIInstrInserter()); 614 615 if (TT.isOSWindows()) { 616 // Identify valid longjmp targets for Windows Control Flow Guard. 617 addPass(createCFGuardLongjmpPass()); 618 // Identify valid eh continuation targets for Windows EHCont Guard. 619 addPass(createEHContGuardCatchretPass()); 620 } 621 addPass(createX86LoadValueInjectionRetHardeningPass()); 622 623 // Insert pseudo probe annotation for callsite profiling 624 addPass(createPseudoProbeInserter()); 625 626 // KCFI indirect call checks are lowered to a bundle, and on Darwin platforms, 627 // also CALL_RVMARKER. 628 addPass(createUnpackMachineBundles([&TT](const MachineFunction &MF) { 629 // Only run bundle expansion if the module uses kcfi, or there are relevant 630 // ObjC runtime functions present in the module. 631 const Function &F = MF.getFunction(); 632 const Module *M = F.getParent(); 633 return M->getModuleFlag("kcfi") || 634 (TT.isOSDarwin() && 635 (M->getFunction("objc_retainAutoreleasedReturnValue") || 636 M->getFunction("objc_unsafeClaimAutoreleasedReturnValue"))); 637 })); 638 } 639 640 bool X86PassConfig::addPostFastRegAllocRewrite() { 641 addPass(createX86FastTileConfigPass()); 642 return true; 643 } 644 645 std::unique_ptr<CSEConfigBase> X86PassConfig::getCSEConfig() const { 646 return getStandardCSEConfigForOpt(TM->getOptLevel()); 647 } 648 649 static bool onlyAllocateTileRegisters(const TargetRegisterInfo &TRI, 650 const TargetRegisterClass &RC) { 651 return static_cast<const X86RegisterInfo &>(TRI).isTileRegisterClass(&RC); 652 } 653 654 bool X86PassConfig::addRegAssignAndRewriteOptimized() { 655 // Don't support tile RA when RA is specified by command line "-regalloc". 656 if (!isCustomizedRegAlloc() && EnableTileRAPass) { 657 // Allocate tile register first. 658 addPass(createGreedyRegisterAllocator(onlyAllocateTileRegisters)); 659 addPass(createX86TileConfigPass()); 660 } 661 return TargetPassConfig::addRegAssignAndRewriteOptimized(); 662 } 663