1 //===- TargetPassConfig.cpp - Target independent code generation passes ---===// 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 interfaces to access the target independent code 10 // generation passes provided by the LLVM backend. 11 // 12 //===---------------------------------------------------------------------===// 13 14 #include "llvm/CodeGen/TargetPassConfig.h" 15 #include "llvm/ADT/DenseMap.h" 16 #include "llvm/ADT/SmallVector.h" 17 #include "llvm/ADT/StringRef.h" 18 #include "llvm/Analysis/BasicAliasAnalysis.h" 19 #include "llvm/Analysis/CFLAndersAliasAnalysis.h" 20 #include "llvm/Analysis/CFLSteensAliasAnalysis.h" 21 #include "llvm/Analysis/CallGraphSCCPass.h" 22 #include "llvm/Analysis/ScopedNoAliasAA.h" 23 #include "llvm/Analysis/TargetTransformInfo.h" 24 #include "llvm/Analysis/TypeBasedAliasAnalysis.h" 25 #include "llvm/CodeGen/CSEConfigBase.h" 26 #include "llvm/CodeGen/MachineFunctionPass.h" 27 #include "llvm/CodeGen/MachinePassRegistry.h" 28 #include "llvm/CodeGen/Passes.h" 29 #include "llvm/CodeGen/RegAllocRegistry.h" 30 #include "llvm/IR/IRPrintingPasses.h" 31 #include "llvm/IR/LegacyPassManager.h" 32 #include "llvm/IR/Verifier.h" 33 #include "llvm/InitializePasses.h" 34 #include "llvm/MC/MCAsmInfo.h" 35 #include "llvm/MC/MCTargetOptions.h" 36 #include "llvm/Pass.h" 37 #include "llvm/Support/CodeGen.h" 38 #include "llvm/Support/CommandLine.h" 39 #include "llvm/Support/Compiler.h" 40 #include "llvm/Support/Debug.h" 41 #include "llvm/Support/ErrorHandling.h" 42 #include "llvm/Support/SaveAndRestore.h" 43 #include "llvm/Support/Threading.h" 44 #include "llvm/Target/TargetMachine.h" 45 #include "llvm/Transforms/Scalar.h" 46 #include "llvm/Transforms/Utils.h" 47 #include "llvm/Transforms/Utils/SymbolRewriter.h" 48 #include <cassert> 49 #include <string> 50 51 using namespace llvm; 52 53 static cl::opt<bool> 54 EnableIPRA("enable-ipra", cl::init(false), cl::Hidden, 55 cl::desc("Enable interprocedural register allocation " 56 "to reduce load/store at procedure calls.")); 57 static cl::opt<bool> DisablePostRASched("disable-post-ra", cl::Hidden, 58 cl::desc("Disable Post Regalloc Scheduler")); 59 static cl::opt<bool> DisableBranchFold("disable-branch-fold", cl::Hidden, 60 cl::desc("Disable branch folding")); 61 static cl::opt<bool> DisableTailDuplicate("disable-tail-duplicate", cl::Hidden, 62 cl::desc("Disable tail duplication")); 63 static cl::opt<bool> DisableEarlyTailDup("disable-early-taildup", cl::Hidden, 64 cl::desc("Disable pre-register allocation tail duplication")); 65 static cl::opt<bool> DisableBlockPlacement("disable-block-placement", 66 cl::Hidden, cl::desc("Disable probability-driven block placement")); 67 static cl::opt<bool> EnableBlockPlacementStats("enable-block-placement-stats", 68 cl::Hidden, cl::desc("Collect probability-driven block placement stats")); 69 static cl::opt<bool> DisableSSC("disable-ssc", cl::Hidden, 70 cl::desc("Disable Stack Slot Coloring")); 71 static cl::opt<bool> DisableMachineDCE("disable-machine-dce", cl::Hidden, 72 cl::desc("Disable Machine Dead Code Elimination")); 73 static cl::opt<bool> DisableEarlyIfConversion("disable-early-ifcvt", cl::Hidden, 74 cl::desc("Disable Early If-conversion")); 75 static cl::opt<bool> DisableMachineLICM("disable-machine-licm", cl::Hidden, 76 cl::desc("Disable Machine LICM")); 77 static cl::opt<bool> DisableMachineCSE("disable-machine-cse", cl::Hidden, 78 cl::desc("Disable Machine Common Subexpression Elimination")); 79 static cl::opt<cl::boolOrDefault> OptimizeRegAlloc( 80 "optimize-regalloc", cl::Hidden, 81 cl::desc("Enable optimized register allocation compilation path.")); 82 static cl::opt<bool> DisablePostRAMachineLICM("disable-postra-machine-licm", 83 cl::Hidden, 84 cl::desc("Disable Machine LICM")); 85 static cl::opt<bool> DisableMachineSink("disable-machine-sink", cl::Hidden, 86 cl::desc("Disable Machine Sinking")); 87 static cl::opt<bool> DisablePostRAMachineSink("disable-postra-machine-sink", 88 cl::Hidden, 89 cl::desc("Disable PostRA Machine Sinking")); 90 static cl::opt<bool> DisableLSR("disable-lsr", cl::Hidden, 91 cl::desc("Disable Loop Strength Reduction Pass")); 92 static cl::opt<bool> DisableConstantHoisting("disable-constant-hoisting", 93 cl::Hidden, cl::desc("Disable ConstantHoisting")); 94 static cl::opt<bool> DisableCGP("disable-cgp", cl::Hidden, 95 cl::desc("Disable Codegen Prepare")); 96 static cl::opt<bool> DisableCopyProp("disable-copyprop", cl::Hidden, 97 cl::desc("Disable Copy Propagation pass")); 98 static cl::opt<bool> DisablePartialLibcallInlining("disable-partial-libcall-inlining", 99 cl::Hidden, cl::desc("Disable Partial Libcall Inlining")); 100 static cl::opt<bool> EnableImplicitNullChecks( 101 "enable-implicit-null-checks", 102 cl::desc("Fold null checks into faulting memory operations"), 103 cl::init(false), cl::Hidden); 104 static cl::opt<bool> DisableMergeICmps("disable-mergeicmps", 105 cl::desc("Disable MergeICmps Pass"), 106 cl::init(false), cl::Hidden); 107 static cl::opt<bool> PrintLSR("print-lsr-output", cl::Hidden, 108 cl::desc("Print LLVM IR produced by the loop-reduce pass")); 109 static cl::opt<bool> PrintISelInput("print-isel-input", cl::Hidden, 110 cl::desc("Print LLVM IR input to isel pass")); 111 static cl::opt<bool> PrintGCInfo("print-gc", cl::Hidden, 112 cl::desc("Dump garbage collector data")); 113 static cl::opt<cl::boolOrDefault> 114 VerifyMachineCode("verify-machineinstrs", cl::Hidden, 115 cl::desc("Verify generated machine code"), 116 cl::ZeroOrMore); 117 enum RunOutliner { AlwaysOutline, NeverOutline, TargetDefault }; 118 // Enable or disable the MachineOutliner. 119 static cl::opt<RunOutliner> EnableMachineOutliner( 120 "enable-machine-outliner", cl::desc("Enable the machine outliner"), 121 cl::Hidden, cl::ValueOptional, cl::init(TargetDefault), 122 cl::values(clEnumValN(AlwaysOutline, "always", 123 "Run on all functions guaranteed to be beneficial"), 124 clEnumValN(NeverOutline, "never", "Disable all outlining"), 125 // Sentinel value for unspecified option. 126 clEnumValN(AlwaysOutline, "", ""))); 127 // Enable or disable FastISel. Both options are needed, because 128 // FastISel is enabled by default with -fast, and we wish to be 129 // able to enable or disable fast-isel independently from -O0. 130 static cl::opt<cl::boolOrDefault> 131 EnableFastISelOption("fast-isel", cl::Hidden, 132 cl::desc("Enable the \"fast\" instruction selector")); 133 134 static cl::opt<cl::boolOrDefault> EnableGlobalISelOption( 135 "global-isel", cl::Hidden, 136 cl::desc("Enable the \"global\" instruction selector")); 137 138 static cl::opt<std::string> PrintMachineInstrs( 139 "print-machineinstrs", cl::ValueOptional, cl::desc("Print machine instrs"), 140 cl::value_desc("pass-name"), cl::init("option-unspecified"), cl::Hidden); 141 142 static cl::opt<GlobalISelAbortMode> EnableGlobalISelAbort( 143 "global-isel-abort", cl::Hidden, 144 cl::desc("Enable abort calls when \"global\" instruction selection " 145 "fails to lower/select an instruction"), 146 cl::values( 147 clEnumValN(GlobalISelAbortMode::Disable, "0", "Disable the abort"), 148 clEnumValN(GlobalISelAbortMode::Enable, "1", "Enable the abort"), 149 clEnumValN(GlobalISelAbortMode::DisableWithDiag, "2", 150 "Disable the abort but emit a diagnostic on failure"))); 151 152 // Temporary option to allow experimenting with MachineScheduler as a post-RA 153 // scheduler. Targets can "properly" enable this with 154 // substitutePass(&PostRASchedulerID, &PostMachineSchedulerID). 155 // Targets can return true in targetSchedulesPostRAScheduling() and 156 // insert a PostRA scheduling pass wherever it wants. 157 static cl::opt<bool> MISchedPostRA( 158 "misched-postra", cl::Hidden, 159 cl::desc( 160 "Run MachineScheduler post regalloc (independent of preRA sched)")); 161 162 // Experimental option to run live interval analysis early. 163 static cl::opt<bool> EarlyLiveIntervals("early-live-intervals", cl::Hidden, 164 cl::desc("Run live interval analysis earlier in the pipeline")); 165 166 // Experimental option to use CFL-AA in codegen 167 enum class CFLAAType { None, Steensgaard, Andersen, Both }; 168 static cl::opt<CFLAAType> UseCFLAA( 169 "use-cfl-aa-in-codegen", cl::init(CFLAAType::None), cl::Hidden, 170 cl::desc("Enable the new, experimental CFL alias analysis in CodeGen"), 171 cl::values(clEnumValN(CFLAAType::None, "none", "Disable CFL-AA"), 172 clEnumValN(CFLAAType::Steensgaard, "steens", 173 "Enable unification-based CFL-AA"), 174 clEnumValN(CFLAAType::Andersen, "anders", 175 "Enable inclusion-based CFL-AA"), 176 clEnumValN(CFLAAType::Both, "both", 177 "Enable both variants of CFL-AA"))); 178 179 /// Option names for limiting the codegen pipeline. 180 /// Those are used in error reporting and we didn't want 181 /// to duplicate their names all over the place. 182 static const char StartAfterOptName[] = "start-after"; 183 static const char StartBeforeOptName[] = "start-before"; 184 static const char StopAfterOptName[] = "stop-after"; 185 static const char StopBeforeOptName[] = "stop-before"; 186 187 static cl::opt<std::string> 188 StartAfterOpt(StringRef(StartAfterOptName), 189 cl::desc("Resume compilation after a specific pass"), 190 cl::value_desc("pass-name"), cl::init(""), cl::Hidden); 191 192 static cl::opt<std::string> 193 StartBeforeOpt(StringRef(StartBeforeOptName), 194 cl::desc("Resume compilation before a specific pass"), 195 cl::value_desc("pass-name"), cl::init(""), cl::Hidden); 196 197 static cl::opt<std::string> 198 StopAfterOpt(StringRef(StopAfterOptName), 199 cl::desc("Stop compilation after a specific pass"), 200 cl::value_desc("pass-name"), cl::init(""), cl::Hidden); 201 202 static cl::opt<std::string> 203 StopBeforeOpt(StringRef(StopBeforeOptName), 204 cl::desc("Stop compilation before a specific pass"), 205 cl::value_desc("pass-name"), cl::init(""), cl::Hidden); 206 207 extern cl::opt<bool> UseRegistersForDeoptValues; 208 209 /// Allow standard passes to be disabled by command line options. This supports 210 /// simple binary flags that either suppress the pass or do nothing. 211 /// i.e. -disable-mypass=false has no effect. 212 /// These should be converted to boolOrDefault in order to use applyOverride. 213 static IdentifyingPassPtr applyDisable(IdentifyingPassPtr PassID, 214 bool Override) { 215 if (Override) 216 return IdentifyingPassPtr(); 217 return PassID; 218 } 219 220 /// Allow standard passes to be disabled by the command line, regardless of who 221 /// is adding the pass. 222 /// 223 /// StandardID is the pass identified in the standard pass pipeline and provided 224 /// to addPass(). It may be a target-specific ID in the case that the target 225 /// directly adds its own pass, but in that case we harmlessly fall through. 226 /// 227 /// TargetID is the pass that the target has configured to override StandardID. 228 /// 229 /// StandardID may be a pseudo ID. In that case TargetID is the name of the real 230 /// pass to run. This allows multiple options to control a single pass depending 231 /// on where in the pipeline that pass is added. 232 static IdentifyingPassPtr overridePass(AnalysisID StandardID, 233 IdentifyingPassPtr TargetID) { 234 if (StandardID == &PostRASchedulerID) 235 return applyDisable(TargetID, DisablePostRASched); 236 237 if (StandardID == &BranchFolderPassID) 238 return applyDisable(TargetID, DisableBranchFold); 239 240 if (StandardID == &TailDuplicateID) 241 return applyDisable(TargetID, DisableTailDuplicate); 242 243 if (StandardID == &EarlyTailDuplicateID) 244 return applyDisable(TargetID, DisableEarlyTailDup); 245 246 if (StandardID == &MachineBlockPlacementID) 247 return applyDisable(TargetID, DisableBlockPlacement); 248 249 if (StandardID == &StackSlotColoringID) 250 return applyDisable(TargetID, DisableSSC); 251 252 if (StandardID == &DeadMachineInstructionElimID) 253 return applyDisable(TargetID, DisableMachineDCE); 254 255 if (StandardID == &EarlyIfConverterID) 256 return applyDisable(TargetID, DisableEarlyIfConversion); 257 258 if (StandardID == &EarlyMachineLICMID) 259 return applyDisable(TargetID, DisableMachineLICM); 260 261 if (StandardID == &MachineCSEID) 262 return applyDisable(TargetID, DisableMachineCSE); 263 264 if (StandardID == &MachineLICMID) 265 return applyDisable(TargetID, DisablePostRAMachineLICM); 266 267 if (StandardID == &MachineSinkingID) 268 return applyDisable(TargetID, DisableMachineSink); 269 270 if (StandardID == &PostRAMachineSinkingID) 271 return applyDisable(TargetID, DisablePostRAMachineSink); 272 273 if (StandardID == &MachineCopyPropagationID) 274 return applyDisable(TargetID, DisableCopyProp); 275 276 return TargetID; 277 } 278 279 //===---------------------------------------------------------------------===// 280 /// TargetPassConfig 281 //===---------------------------------------------------------------------===// 282 283 INITIALIZE_PASS(TargetPassConfig, "targetpassconfig", 284 "Target Pass Configuration", false, false) 285 char TargetPassConfig::ID = 0; 286 287 namespace { 288 289 struct InsertedPass { 290 AnalysisID TargetPassID; 291 IdentifyingPassPtr InsertedPassID; 292 bool VerifyAfter; 293 bool PrintAfter; 294 295 InsertedPass(AnalysisID TargetPassID, IdentifyingPassPtr InsertedPassID, 296 bool VerifyAfter, bool PrintAfter) 297 : TargetPassID(TargetPassID), InsertedPassID(InsertedPassID), 298 VerifyAfter(VerifyAfter), PrintAfter(PrintAfter) {} 299 300 Pass *getInsertedPass() const { 301 assert(InsertedPassID.isValid() && "Illegal Pass ID!"); 302 if (InsertedPassID.isInstance()) 303 return InsertedPassID.getInstance(); 304 Pass *NP = Pass::createPass(InsertedPassID.getID()); 305 assert(NP && "Pass ID not registered"); 306 return NP; 307 } 308 }; 309 310 } // end anonymous namespace 311 312 namespace llvm { 313 314 class PassConfigImpl { 315 public: 316 // List of passes explicitly substituted by this target. Normally this is 317 // empty, but it is a convenient way to suppress or replace specific passes 318 // that are part of a standard pass pipeline without overridding the entire 319 // pipeline. This mechanism allows target options to inherit a standard pass's 320 // user interface. For example, a target may disable a standard pass by 321 // default by substituting a pass ID of zero, and the user may still enable 322 // that standard pass with an explicit command line option. 323 DenseMap<AnalysisID,IdentifyingPassPtr> TargetPasses; 324 325 /// Store the pairs of <AnalysisID, AnalysisID> of which the second pass 326 /// is inserted after each instance of the first one. 327 SmallVector<InsertedPass, 4> InsertedPasses; 328 }; 329 330 } // end namespace llvm 331 332 // Out of line virtual method. 333 TargetPassConfig::~TargetPassConfig() { 334 delete Impl; 335 } 336 337 static const PassInfo *getPassInfo(StringRef PassName) { 338 if (PassName.empty()) 339 return nullptr; 340 341 const PassRegistry &PR = *PassRegistry::getPassRegistry(); 342 const PassInfo *PI = PR.getPassInfo(PassName); 343 if (!PI) 344 report_fatal_error(Twine('\"') + Twine(PassName) + 345 Twine("\" pass is not registered.")); 346 return PI; 347 } 348 349 static AnalysisID getPassIDFromName(StringRef PassName) { 350 const PassInfo *PI = getPassInfo(PassName); 351 return PI ? PI->getTypeInfo() : nullptr; 352 } 353 354 static std::pair<StringRef, unsigned> 355 getPassNameAndInstanceNum(StringRef PassName) { 356 StringRef Name, InstanceNumStr; 357 std::tie(Name, InstanceNumStr) = PassName.split(','); 358 359 unsigned InstanceNum = 0; 360 if (!InstanceNumStr.empty() && InstanceNumStr.getAsInteger(10, InstanceNum)) 361 report_fatal_error("invalid pass instance specifier " + PassName); 362 363 return std::make_pair(Name, InstanceNum); 364 } 365 366 void TargetPassConfig::setStartStopPasses() { 367 StringRef StartBeforeName; 368 std::tie(StartBeforeName, StartBeforeInstanceNum) = 369 getPassNameAndInstanceNum(StartBeforeOpt); 370 371 StringRef StartAfterName; 372 std::tie(StartAfterName, StartAfterInstanceNum) = 373 getPassNameAndInstanceNum(StartAfterOpt); 374 375 StringRef StopBeforeName; 376 std::tie(StopBeforeName, StopBeforeInstanceNum) 377 = getPassNameAndInstanceNum(StopBeforeOpt); 378 379 StringRef StopAfterName; 380 std::tie(StopAfterName, StopAfterInstanceNum) 381 = getPassNameAndInstanceNum(StopAfterOpt); 382 383 StartBefore = getPassIDFromName(StartBeforeName); 384 StartAfter = getPassIDFromName(StartAfterName); 385 StopBefore = getPassIDFromName(StopBeforeName); 386 StopAfter = getPassIDFromName(StopAfterName); 387 if (StartBefore && StartAfter) 388 report_fatal_error(Twine(StartBeforeOptName) + Twine(" and ") + 389 Twine(StartAfterOptName) + Twine(" specified!")); 390 if (StopBefore && StopAfter) 391 report_fatal_error(Twine(StopBeforeOptName) + Twine(" and ") + 392 Twine(StopAfterOptName) + Twine(" specified!")); 393 Started = (StartAfter == nullptr) && (StartBefore == nullptr); 394 } 395 396 // Out of line constructor provides default values for pass options and 397 // registers all common codegen passes. 398 TargetPassConfig::TargetPassConfig(LLVMTargetMachine &TM, PassManagerBase &pm) 399 : ImmutablePass(ID), PM(&pm), TM(&TM) { 400 Impl = new PassConfigImpl(); 401 402 // Register all target independent codegen passes to activate their PassIDs, 403 // including this pass itself. 404 initializeCodeGen(*PassRegistry::getPassRegistry()); 405 406 // Also register alias analysis passes required by codegen passes. 407 initializeBasicAAWrapperPassPass(*PassRegistry::getPassRegistry()); 408 initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry()); 409 410 if (StringRef(PrintMachineInstrs.getValue()).equals("")) 411 TM.Options.PrintMachineCode = true; 412 413 if (EnableIPRA.getNumOccurrences()) 414 TM.Options.EnableIPRA = EnableIPRA; 415 else { 416 // If not explicitly specified, use target default. 417 TM.Options.EnableIPRA |= TM.useIPRA(); 418 } 419 420 if (TM.Options.EnableIPRA) 421 setRequiresCodeGenSCCOrder(); 422 423 if (EnableGlobalISelAbort.getNumOccurrences()) 424 TM.Options.GlobalISelAbort = EnableGlobalISelAbort; 425 426 setStartStopPasses(); 427 } 428 429 CodeGenOpt::Level TargetPassConfig::getOptLevel() const { 430 return TM->getOptLevel(); 431 } 432 433 /// Insert InsertedPassID pass after TargetPassID. 434 void TargetPassConfig::insertPass(AnalysisID TargetPassID, 435 IdentifyingPassPtr InsertedPassID, 436 bool VerifyAfter, bool PrintAfter) { 437 assert(((!InsertedPassID.isInstance() && 438 TargetPassID != InsertedPassID.getID()) || 439 (InsertedPassID.isInstance() && 440 TargetPassID != InsertedPassID.getInstance()->getPassID())) && 441 "Insert a pass after itself!"); 442 Impl->InsertedPasses.emplace_back(TargetPassID, InsertedPassID, VerifyAfter, 443 PrintAfter); 444 } 445 446 /// createPassConfig - Create a pass configuration object to be used by 447 /// addPassToEmitX methods for generating a pipeline of CodeGen passes. 448 /// 449 /// Targets may override this to extend TargetPassConfig. 450 TargetPassConfig *LLVMTargetMachine::createPassConfig(PassManagerBase &PM) { 451 return new TargetPassConfig(*this, PM); 452 } 453 454 TargetPassConfig::TargetPassConfig() 455 : ImmutablePass(ID) { 456 report_fatal_error("Trying to construct TargetPassConfig without a target " 457 "machine. Scheduling a CodeGen pass without a target " 458 "triple set?"); 459 } 460 461 bool TargetPassConfig::willCompleteCodeGenPipeline() { 462 return StopBeforeOpt.empty() && StopAfterOpt.empty(); 463 } 464 465 bool TargetPassConfig::hasLimitedCodeGenPipeline() { 466 return !StartBeforeOpt.empty() || !StartAfterOpt.empty() || 467 !willCompleteCodeGenPipeline(); 468 } 469 470 std::string 471 TargetPassConfig::getLimitedCodeGenPipelineReason(const char *Separator) const { 472 if (!hasLimitedCodeGenPipeline()) 473 return std::string(); 474 std::string Res; 475 static cl::opt<std::string> *PassNames[] = {&StartAfterOpt, &StartBeforeOpt, 476 &StopAfterOpt, &StopBeforeOpt}; 477 static const char *OptNames[] = {StartAfterOptName, StartBeforeOptName, 478 StopAfterOptName, StopBeforeOptName}; 479 bool IsFirst = true; 480 for (int Idx = 0; Idx < 4; ++Idx) 481 if (!PassNames[Idx]->empty()) { 482 if (!IsFirst) 483 Res += Separator; 484 IsFirst = false; 485 Res += OptNames[Idx]; 486 } 487 return Res; 488 } 489 490 // Helper to verify the analysis is really immutable. 491 void TargetPassConfig::setOpt(bool &Opt, bool Val) { 492 assert(!Initialized && "PassConfig is immutable"); 493 Opt = Val; 494 } 495 496 void TargetPassConfig::substitutePass(AnalysisID StandardID, 497 IdentifyingPassPtr TargetID) { 498 Impl->TargetPasses[StandardID] = TargetID; 499 } 500 501 IdentifyingPassPtr TargetPassConfig::getPassSubstitution(AnalysisID ID) const { 502 DenseMap<AnalysisID, IdentifyingPassPtr>::const_iterator 503 I = Impl->TargetPasses.find(ID); 504 if (I == Impl->TargetPasses.end()) 505 return ID; 506 return I->second; 507 } 508 509 bool TargetPassConfig::isPassSubstitutedOrOverridden(AnalysisID ID) const { 510 IdentifyingPassPtr TargetID = getPassSubstitution(ID); 511 IdentifyingPassPtr FinalPtr = overridePass(ID, TargetID); 512 return !FinalPtr.isValid() || FinalPtr.isInstance() || 513 FinalPtr.getID() != ID; 514 } 515 516 /// Add a pass to the PassManager if that pass is supposed to be run. If the 517 /// Started/Stopped flags indicate either that the compilation should start at 518 /// a later pass or that it should stop after an earlier pass, then do not add 519 /// the pass. Finally, compare the current pass against the StartAfter 520 /// and StopAfter options and change the Started/Stopped flags accordingly. 521 void TargetPassConfig::addPass(Pass *P, bool verifyAfter, bool printAfter) { 522 assert(!Initialized && "PassConfig is immutable"); 523 524 // Cache the Pass ID here in case the pass manager finds this pass is 525 // redundant with ones already scheduled / available, and deletes it. 526 // Fundamentally, once we add the pass to the manager, we no longer own it 527 // and shouldn't reference it. 528 AnalysisID PassID = P->getPassID(); 529 530 if (StartBefore == PassID && StartBeforeCount++ == StartBeforeInstanceNum) 531 Started = true; 532 if (StopBefore == PassID && StopBeforeCount++ == StopBeforeInstanceNum) 533 Stopped = true; 534 if (Started && !Stopped) { 535 std::string Banner; 536 // Construct banner message before PM->add() as that may delete the pass. 537 if (AddingMachinePasses && (printAfter || verifyAfter)) 538 Banner = std::string("After ") + std::string(P->getPassName()); 539 PM->add(P); 540 if (AddingMachinePasses) { 541 if (printAfter) 542 addPrintPass(Banner); 543 if (verifyAfter) 544 addVerifyPass(Banner); 545 } 546 547 // Add the passes after the pass P if there is any. 548 for (auto IP : Impl->InsertedPasses) { 549 if (IP.TargetPassID == PassID) 550 addPass(IP.getInsertedPass(), IP.VerifyAfter, IP.PrintAfter); 551 } 552 } else { 553 delete P; 554 } 555 556 if (StopAfter == PassID && StopAfterCount++ == StopAfterInstanceNum) 557 Stopped = true; 558 559 if (StartAfter == PassID && StartAfterCount++ == StartAfterInstanceNum) 560 Started = true; 561 if (Stopped && !Started) 562 report_fatal_error("Cannot stop compilation after pass that is not run"); 563 } 564 565 /// Add a CodeGen pass at this point in the pipeline after checking for target 566 /// and command line overrides. 567 /// 568 /// addPass cannot return a pointer to the pass instance because is internal the 569 /// PassManager and the instance we create here may already be freed. 570 AnalysisID TargetPassConfig::addPass(AnalysisID PassID, bool verifyAfter, 571 bool printAfter) { 572 IdentifyingPassPtr TargetID = getPassSubstitution(PassID); 573 IdentifyingPassPtr FinalPtr = overridePass(PassID, TargetID); 574 if (!FinalPtr.isValid()) 575 return nullptr; 576 577 Pass *P; 578 if (FinalPtr.isInstance()) 579 P = FinalPtr.getInstance(); 580 else { 581 P = Pass::createPass(FinalPtr.getID()); 582 if (!P) 583 llvm_unreachable("Pass ID not registered"); 584 } 585 AnalysisID FinalID = P->getPassID(); 586 addPass(P, verifyAfter, printAfter); // Ends the lifetime of P. 587 588 return FinalID; 589 } 590 591 void TargetPassConfig::printAndVerify(const std::string &Banner) { 592 addPrintPass(Banner); 593 addVerifyPass(Banner); 594 } 595 596 void TargetPassConfig::addPrintPass(const std::string &Banner) { 597 if (TM->shouldPrintMachineCode()) 598 PM->add(createMachineFunctionPrinterPass(dbgs(), Banner)); 599 } 600 601 void TargetPassConfig::addVerifyPass(const std::string &Banner) { 602 bool Verify = VerifyMachineCode == cl::BOU_TRUE; 603 #ifdef EXPENSIVE_CHECKS 604 if (VerifyMachineCode == cl::BOU_UNSET) 605 Verify = TM->isMachineVerifierClean(); 606 #endif 607 if (Verify) 608 PM->add(createMachineVerifierPass(Banner)); 609 } 610 611 /// Add common target configurable passes that perform LLVM IR to IR transforms 612 /// following machine independent optimization. 613 void TargetPassConfig::addIRPasses() { 614 switch (UseCFLAA) { 615 case CFLAAType::Steensgaard: 616 addPass(createCFLSteensAAWrapperPass()); 617 break; 618 case CFLAAType::Andersen: 619 addPass(createCFLAndersAAWrapperPass()); 620 break; 621 case CFLAAType::Both: 622 addPass(createCFLAndersAAWrapperPass()); 623 addPass(createCFLSteensAAWrapperPass()); 624 break; 625 default: 626 break; 627 } 628 629 // Basic AliasAnalysis support. 630 // Add TypeBasedAliasAnalysis before BasicAliasAnalysis so that 631 // BasicAliasAnalysis wins if they disagree. This is intended to help 632 // support "obvious" type-punning idioms. 633 addPass(createTypeBasedAAWrapperPass()); 634 addPass(createScopedNoAliasAAWrapperPass()); 635 addPass(createBasicAAWrapperPass()); 636 637 // Before running any passes, run the verifier to determine if the input 638 // coming from the front-end and/or optimizer is valid. 639 if (!DisableVerify) 640 addPass(createVerifierPass()); 641 642 // Run loop strength reduction before anything else. 643 if (getOptLevel() != CodeGenOpt::None && !DisableLSR) { 644 addPass(createLoopStrengthReducePass()); 645 if (PrintLSR) 646 addPass(createPrintFunctionPass(dbgs(), "\n\n*** Code after LSR ***\n")); 647 } 648 649 if (getOptLevel() != CodeGenOpt::None) { 650 // The MergeICmpsPass tries to create memcmp calls by grouping sequences of 651 // loads and compares. ExpandMemCmpPass then tries to expand those calls 652 // into optimally-sized loads and compares. The transforms are enabled by a 653 // target lowering hook. 654 if (!DisableMergeICmps) 655 addPass(createMergeICmpsLegacyPass()); 656 addPass(createExpandMemCmpPass()); 657 } 658 659 // Run GC lowering passes for builtin collectors 660 // TODO: add a pass insertion point here 661 addPass(createGCLoweringPass()); 662 addPass(createShadowStackGCLoweringPass()); 663 addPass(createLowerConstantIntrinsicsPass()); 664 665 // Make sure that no unreachable blocks are instruction selected. 666 addPass(createUnreachableBlockEliminationPass()); 667 668 // Prepare expensive constants for SelectionDAG. 669 if (getOptLevel() != CodeGenOpt::None && !DisableConstantHoisting) 670 addPass(createConstantHoistingPass()); 671 672 if (getOptLevel() != CodeGenOpt::None && !DisablePartialLibcallInlining) 673 addPass(createPartiallyInlineLibCallsPass()); 674 675 // Instrument function entry and exit, e.g. with calls to mcount(). 676 addPass(createPostInlineEntryExitInstrumenterPass()); 677 678 // Add scalarization of target's unsupported masked memory intrinsics pass. 679 // the unsupported intrinsic will be replaced with a chain of basic blocks, 680 // that stores/loads element one-by-one if the appropriate mask bit is set. 681 addPass(createScalarizeMaskedMemIntrinPass()); 682 683 // Expand reduction intrinsics into shuffle sequences if the target wants to. 684 addPass(createExpandReductionsPass()); 685 } 686 687 /// Turn exception handling constructs into something the code generators can 688 /// handle. 689 void TargetPassConfig::addPassesToHandleExceptions() { 690 const MCAsmInfo *MCAI = TM->getMCAsmInfo(); 691 assert(MCAI && "No MCAsmInfo"); 692 switch (MCAI->getExceptionHandlingType()) { 693 case ExceptionHandling::SjLj: 694 // SjLj piggy-backs on dwarf for this bit. The cleanups done apply to both 695 // Dwarf EH prepare needs to be run after SjLj prepare. Otherwise, 696 // catch info can get misplaced when a selector ends up more than one block 697 // removed from the parent invoke(s). This could happen when a landing 698 // pad is shared by multiple invokes and is also a target of a normal 699 // edge from elsewhere. 700 addPass(createSjLjEHPreparePass(TM)); 701 LLVM_FALLTHROUGH; 702 case ExceptionHandling::DwarfCFI: 703 case ExceptionHandling::ARM: 704 addPass(createDwarfEHPass()); 705 break; 706 case ExceptionHandling::WinEH: 707 // We support using both GCC-style and MSVC-style exceptions on Windows, so 708 // add both preparation passes. Each pass will only actually run if it 709 // recognizes the personality function. 710 addPass(createWinEHPass()); 711 addPass(createDwarfEHPass()); 712 break; 713 case ExceptionHandling::Wasm: 714 // Wasm EH uses Windows EH instructions, but it does not need to demote PHIs 715 // on catchpads and cleanuppads because it does not outline them into 716 // funclets. Catchswitch blocks are not lowered in SelectionDAG, so we 717 // should remove PHIs there. 718 addPass(createWinEHPass(/*DemoteCatchSwitchPHIOnly=*/false)); 719 addPass(createWasmEHPass()); 720 break; 721 case ExceptionHandling::None: 722 addPass(createLowerInvokePass()); 723 724 // The lower invoke pass may create unreachable code. Remove it. 725 addPass(createUnreachableBlockEliminationPass()); 726 break; 727 } 728 } 729 730 /// Add pass to prepare the LLVM IR for code generation. This should be done 731 /// before exception handling preparation passes. 732 void TargetPassConfig::addCodeGenPrepare() { 733 if (getOptLevel() != CodeGenOpt::None && !DisableCGP) 734 addPass(createCodeGenPreparePass()); 735 addPass(createRewriteSymbolsPass()); 736 } 737 738 /// Add common passes that perform LLVM IR to IR transforms in preparation for 739 /// instruction selection. 740 void TargetPassConfig::addISelPrepare() { 741 addPreISel(); 742 743 // Force codegen to run according to the callgraph. 744 if (requiresCodeGenSCCOrder()) 745 addPass(new DummyCGSCCPass); 746 747 // Add both the safe stack and the stack protection passes: each of them will 748 // only protect functions that have corresponding attributes. 749 addPass(createSafeStackPass()); 750 addPass(createStackProtectorPass()); 751 752 if (PrintISelInput) 753 addPass(createPrintFunctionPass( 754 dbgs(), "\n\n*** Final LLVM Code input to ISel ***\n")); 755 756 // All passes which modify the LLVM IR are now complete; run the verifier 757 // to ensure that the IR is valid. 758 if (!DisableVerify) 759 addPass(createVerifierPass()); 760 } 761 762 bool TargetPassConfig::addCoreISelPasses() { 763 // Enable FastISel with -fast-isel, but allow that to be overridden. 764 TM->setO0WantsFastISel(EnableFastISelOption != cl::BOU_FALSE); 765 766 // Determine an instruction selector. 767 enum class SelectorType { SelectionDAG, FastISel, GlobalISel }; 768 SelectorType Selector; 769 770 if (EnableFastISelOption == cl::BOU_TRUE) 771 Selector = SelectorType::FastISel; 772 else if (EnableGlobalISelOption == cl::BOU_TRUE || 773 (TM->Options.EnableGlobalISel && 774 EnableGlobalISelOption != cl::BOU_FALSE)) 775 Selector = SelectorType::GlobalISel; 776 else if (TM->getOptLevel() == CodeGenOpt::None && TM->getO0WantsFastISel()) 777 Selector = SelectorType::FastISel; 778 else 779 Selector = SelectorType::SelectionDAG; 780 781 // Set consistently TM->Options.EnableFastISel and EnableGlobalISel. 782 if (Selector == SelectorType::FastISel) { 783 TM->setFastISel(true); 784 TM->setGlobalISel(false); 785 } else if (Selector == SelectorType::GlobalISel) { 786 TM->setFastISel(false); 787 TM->setGlobalISel(true); 788 } 789 790 // Add instruction selector passes. 791 if (Selector == SelectorType::GlobalISel) { 792 SaveAndRestore<bool> SavedAddingMachinePasses(AddingMachinePasses, true); 793 if (addIRTranslator()) 794 return true; 795 796 addPreLegalizeMachineIR(); 797 798 if (addLegalizeMachineIR()) 799 return true; 800 801 // Before running the register bank selector, ask the target if it 802 // wants to run some passes. 803 addPreRegBankSelect(); 804 805 if (addRegBankSelect()) 806 return true; 807 808 addPreGlobalInstructionSelect(); 809 810 if (addGlobalInstructionSelect()) 811 return true; 812 813 // Pass to reset the MachineFunction if the ISel failed. 814 addPass(createResetMachineFunctionPass( 815 reportDiagnosticWhenGlobalISelFallback(), isGlobalISelAbortEnabled())); 816 817 // Provide a fallback path when we do not want to abort on 818 // not-yet-supported input. 819 if (!isGlobalISelAbortEnabled() && addInstSelector()) 820 return true; 821 822 } else if (addInstSelector()) 823 return true; 824 825 // Expand pseudo-instructions emitted by ISel. Don't run the verifier before 826 // FinalizeISel. 827 addPass(&FinalizeISelID); 828 829 // Print the instruction selected machine code... 830 printAndVerify("After Instruction Selection"); 831 832 return false; 833 } 834 835 bool TargetPassConfig::addISelPasses() { 836 if (TM->useEmulatedTLS()) 837 addPass(createLowerEmuTLSPass()); 838 839 addPass(createPreISelIntrinsicLoweringPass()); 840 addPass(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis())); 841 addIRPasses(); 842 addCodeGenPrepare(); 843 addPassesToHandleExceptions(); 844 addISelPrepare(); 845 846 return addCoreISelPasses(); 847 } 848 849 /// -regalloc=... command line option. 850 static FunctionPass *useDefaultRegisterAllocator() { return nullptr; } 851 static cl::opt<RegisterRegAlloc::FunctionPassCtor, false, 852 RegisterPassParser<RegisterRegAlloc>> 853 RegAlloc("regalloc", cl::Hidden, cl::init(&useDefaultRegisterAllocator), 854 cl::desc("Register allocator to use")); 855 856 /// Add the complete set of target-independent postISel code generator passes. 857 /// 858 /// This can be read as the standard order of major LLVM CodeGen stages. Stages 859 /// with nontrivial configuration or multiple passes are broken out below in 860 /// add%Stage routines. 861 /// 862 /// Any TargetPassConfig::addXX routine may be overriden by the Target. The 863 /// addPre/Post methods with empty header implementations allow injecting 864 /// target-specific fixups just before or after major stages. Additionally, 865 /// targets have the flexibility to change pass order within a stage by 866 /// overriding default implementation of add%Stage routines below. Each 867 /// technique has maintainability tradeoffs because alternate pass orders are 868 /// not well supported. addPre/Post works better if the target pass is easily 869 /// tied to a common pass. But if it has subtle dependencies on multiple passes, 870 /// the target should override the stage instead. 871 /// 872 /// TODO: We could use a single addPre/Post(ID) hook to allow pass injection 873 /// before/after any target-independent pass. But it's currently overkill. 874 void TargetPassConfig::addMachinePasses() { 875 AddingMachinePasses = true; 876 877 // Insert a machine instr printer pass after the specified pass. 878 StringRef PrintMachineInstrsPassName = PrintMachineInstrs.getValue(); 879 if (!PrintMachineInstrsPassName.equals("") && 880 !PrintMachineInstrsPassName.equals("option-unspecified")) { 881 if (const PassInfo *TPI = getPassInfo(PrintMachineInstrsPassName)) { 882 const PassRegistry *PR = PassRegistry::getPassRegistry(); 883 const PassInfo *IPI = PR->getPassInfo(StringRef("machineinstr-printer")); 884 assert(IPI && "failed to get \"machineinstr-printer\" PassInfo!"); 885 const char *TID = (const char *)(TPI->getTypeInfo()); 886 const char *IID = (const char *)(IPI->getTypeInfo()); 887 insertPass(TID, IID); 888 } 889 } 890 891 // Add passes that optimize machine instructions in SSA form. 892 if (getOptLevel() != CodeGenOpt::None) { 893 addMachineSSAOptimization(); 894 } else { 895 // If the target requests it, assign local variables to stack slots relative 896 // to one another and simplify frame index references where possible. 897 addPass(&LocalStackSlotAllocationID, false); 898 } 899 900 if (TM->Options.EnableIPRA) 901 addPass(createRegUsageInfoPropPass()); 902 903 // Run pre-ra passes. 904 addPreRegAlloc(); 905 906 // Run register allocation and passes that are tightly coupled with it, 907 // including phi elimination and scheduling. 908 if (getOptimizeRegAlloc()) 909 addOptimizedRegAlloc(); 910 else 911 addFastRegAlloc(); 912 913 // Run post-ra passes. 914 addPostRegAlloc(); 915 916 if (UseRegistersForDeoptValues) 917 addPass(&FixupStatepointCallerSavedID); 918 919 // Insert prolog/epilog code. Eliminate abstract frame index references... 920 if (getOptLevel() != CodeGenOpt::None) { 921 addPass(&PostRAMachineSinkingID); 922 addPass(&ShrinkWrapID); 923 } 924 925 // Prolog/Epilog inserter needs a TargetMachine to instantiate. But only 926 // do so if it hasn't been disabled, substituted, or overridden. 927 if (!isPassSubstitutedOrOverridden(&PrologEpilogCodeInserterID)) 928 addPass(createPrologEpilogInserterPass()); 929 930 /// Add passes that optimize machine instructions after register allocation. 931 if (getOptLevel() != CodeGenOpt::None) 932 addMachineLateOptimization(); 933 934 // Expand pseudo instructions before second scheduling pass. 935 addPass(&ExpandPostRAPseudosID); 936 937 // Run pre-sched2 passes. 938 addPreSched2(); 939 940 if (EnableImplicitNullChecks) 941 addPass(&ImplicitNullChecksID); 942 943 // Second pass scheduler. 944 // Let Target optionally insert this pass by itself at some other 945 // point. 946 if (getOptLevel() != CodeGenOpt::None && 947 !TM->targetSchedulesPostRAScheduling()) { 948 if (MISchedPostRA) 949 addPass(&PostMachineSchedulerID); 950 else 951 addPass(&PostRASchedulerID); 952 } 953 954 // GC 955 if (addGCPasses()) { 956 if (PrintGCInfo) 957 addPass(createGCInfoPrinter(dbgs()), false, false); 958 } 959 960 // Basic block placement. 961 if (getOptLevel() != CodeGenOpt::None) 962 addBlockPlacement(); 963 964 // Insert before XRay Instrumentation. 965 addPass(&FEntryInserterID, false); 966 967 addPass(&XRayInstrumentationID, false); 968 addPass(&PatchableFunctionID, false); 969 970 addPreEmitPass(); 971 972 if (TM->Options.EnableIPRA) 973 // Collect register usage information and produce a register mask of 974 // clobbered registers, to be used to optimize call sites. 975 addPass(createRegUsageInfoCollector()); 976 977 addPass(&FuncletLayoutID, false); 978 979 addPass(&StackMapLivenessID, false); 980 addPass(&LiveDebugValuesID, false); 981 982 if (TM->Options.EnableMachineOutliner && getOptLevel() != CodeGenOpt::None && 983 EnableMachineOutliner != NeverOutline) { 984 bool RunOnAllFunctions = (EnableMachineOutliner == AlwaysOutline); 985 bool AddOutliner = RunOnAllFunctions || 986 TM->Options.SupportsDefaultOutlining; 987 if (AddOutliner) 988 addPass(createMachineOutlinerPass(RunOnAllFunctions)); 989 } 990 991 if (TM->getBBSectionsType() != llvm::BasicBlockSection::None) 992 addPass(llvm::createBBSectionsPreparePass(TM->getBBSectionsFuncListBuf())); 993 994 // Add passes that directly emit MI after all other MI passes. 995 addPreEmitPass2(); 996 997 AddingMachinePasses = false; 998 } 999 1000 /// Add passes that optimize machine instructions in SSA form. 1001 void TargetPassConfig::addMachineSSAOptimization() { 1002 // Pre-ra tail duplication. 1003 addPass(&EarlyTailDuplicateID); 1004 1005 // Optimize PHIs before DCE: removing dead PHI cycles may make more 1006 // instructions dead. 1007 addPass(&OptimizePHIsID, false); 1008 1009 // This pass merges large allocas. StackSlotColoring is a different pass 1010 // which merges spill slots. 1011 addPass(&StackColoringID, false); 1012 1013 // If the target requests it, assign local variables to stack slots relative 1014 // to one another and simplify frame index references where possible. 1015 addPass(&LocalStackSlotAllocationID, false); 1016 1017 // With optimization, dead code should already be eliminated. However 1018 // there is one known exception: lowered code for arguments that are only 1019 // used by tail calls, where the tail calls reuse the incoming stack 1020 // arguments directly (see t11 in test/CodeGen/X86/sibcall.ll). 1021 addPass(&DeadMachineInstructionElimID); 1022 1023 // Allow targets to insert passes that improve instruction level parallelism, 1024 // like if-conversion. Such passes will typically need dominator trees and 1025 // loop info, just like LICM and CSE below. 1026 addILPOpts(); 1027 1028 addPass(&EarlyMachineLICMID, false); 1029 addPass(&MachineCSEID, false); 1030 1031 addPass(&MachineSinkingID); 1032 1033 addPass(&PeepholeOptimizerID); 1034 // Clean-up the dead code that may have been generated by peephole 1035 // rewriting. 1036 addPass(&DeadMachineInstructionElimID); 1037 } 1038 1039 //===---------------------------------------------------------------------===// 1040 /// Register Allocation Pass Configuration 1041 //===---------------------------------------------------------------------===// 1042 1043 bool TargetPassConfig::getOptimizeRegAlloc() const { 1044 switch (OptimizeRegAlloc) { 1045 case cl::BOU_UNSET: return getOptLevel() != CodeGenOpt::None; 1046 case cl::BOU_TRUE: return true; 1047 case cl::BOU_FALSE: return false; 1048 } 1049 llvm_unreachable("Invalid optimize-regalloc state"); 1050 } 1051 1052 /// A dummy default pass factory indicates whether the register allocator is 1053 /// overridden on the command line. 1054 static llvm::once_flag InitializeDefaultRegisterAllocatorFlag; 1055 1056 static RegisterRegAlloc 1057 defaultRegAlloc("default", 1058 "pick register allocator based on -O option", 1059 useDefaultRegisterAllocator); 1060 1061 static void initializeDefaultRegisterAllocatorOnce() { 1062 if (!RegisterRegAlloc::getDefault()) 1063 RegisterRegAlloc::setDefault(RegAlloc); 1064 } 1065 1066 /// Instantiate the default register allocator pass for this target for either 1067 /// the optimized or unoptimized allocation path. This will be added to the pass 1068 /// manager by addFastRegAlloc in the unoptimized case or addOptimizedRegAlloc 1069 /// in the optimized case. 1070 /// 1071 /// A target that uses the standard regalloc pass order for fast or optimized 1072 /// allocation may still override this for per-target regalloc 1073 /// selection. But -regalloc=... always takes precedence. 1074 FunctionPass *TargetPassConfig::createTargetRegisterAllocator(bool Optimized) { 1075 if (Optimized) 1076 return createGreedyRegisterAllocator(); 1077 else 1078 return createFastRegisterAllocator(); 1079 } 1080 1081 /// Find and instantiate the register allocation pass requested by this target 1082 /// at the current optimization level. Different register allocators are 1083 /// defined as separate passes because they may require different analysis. 1084 /// 1085 /// This helper ensures that the regalloc= option is always available, 1086 /// even for targets that override the default allocator. 1087 /// 1088 /// FIXME: When MachinePassRegistry register pass IDs instead of function ptrs, 1089 /// this can be folded into addPass. 1090 FunctionPass *TargetPassConfig::createRegAllocPass(bool Optimized) { 1091 // Initialize the global default. 1092 llvm::call_once(InitializeDefaultRegisterAllocatorFlag, 1093 initializeDefaultRegisterAllocatorOnce); 1094 1095 RegisterRegAlloc::FunctionPassCtor Ctor = RegisterRegAlloc::getDefault(); 1096 if (Ctor != useDefaultRegisterAllocator) 1097 return Ctor(); 1098 1099 // With no -regalloc= override, ask the target for a regalloc pass. 1100 return createTargetRegisterAllocator(Optimized); 1101 } 1102 1103 bool TargetPassConfig::addRegAssignmentFast() { 1104 if (RegAlloc != &useDefaultRegisterAllocator && 1105 RegAlloc != &createFastRegisterAllocator) 1106 report_fatal_error("Must use fast (default) register allocator for unoptimized regalloc."); 1107 1108 addPass(createRegAllocPass(false)); 1109 return true; 1110 } 1111 1112 bool TargetPassConfig::addRegAssignmentOptimized() { 1113 // Add the selected register allocation pass. 1114 addPass(createRegAllocPass(true)); 1115 1116 // Allow targets to change the register assignments before rewriting. 1117 addPreRewrite(); 1118 1119 // Finally rewrite virtual registers. 1120 addPass(&VirtRegRewriterID); 1121 // Perform stack slot coloring and post-ra machine LICM. 1122 // 1123 // FIXME: Re-enable coloring with register when it's capable of adding 1124 // kill markers. 1125 addPass(&StackSlotColoringID); 1126 1127 return true; 1128 } 1129 1130 /// Return true if the default global register allocator is in use and 1131 /// has not be overriden on the command line with '-regalloc=...' 1132 bool TargetPassConfig::usingDefaultRegAlloc() const { 1133 return RegAlloc.getNumOccurrences() == 0; 1134 } 1135 1136 /// Add the minimum set of target-independent passes that are required for 1137 /// register allocation. No coalescing or scheduling. 1138 void TargetPassConfig::addFastRegAlloc() { 1139 addPass(&PHIEliminationID, false); 1140 addPass(&TwoAddressInstructionPassID, false); 1141 1142 addRegAssignmentFast(); 1143 } 1144 1145 /// Add standard target-independent passes that are tightly coupled with 1146 /// optimized register allocation, including coalescing, machine instruction 1147 /// scheduling, and register allocation itself. 1148 void TargetPassConfig::addOptimizedRegAlloc() { 1149 addPass(&DetectDeadLanesID, false); 1150 1151 addPass(&ProcessImplicitDefsID, false); 1152 1153 // LiveVariables currently requires pure SSA form. 1154 // 1155 // FIXME: Once TwoAddressInstruction pass no longer uses kill flags, 1156 // LiveVariables can be removed completely, and LiveIntervals can be directly 1157 // computed. (We still either need to regenerate kill flags after regalloc, or 1158 // preferably fix the scavenger to not depend on them). 1159 addPass(&LiveVariablesID, false); 1160 1161 // Edge splitting is smarter with machine loop info. 1162 addPass(&MachineLoopInfoID, false); 1163 addPass(&PHIEliminationID, false); 1164 1165 // Eventually, we want to run LiveIntervals before PHI elimination. 1166 if (EarlyLiveIntervals) 1167 addPass(&LiveIntervalsID, false); 1168 1169 addPass(&TwoAddressInstructionPassID, false); 1170 addPass(&RegisterCoalescerID); 1171 1172 // The machine scheduler may accidentally create disconnected components 1173 // when moving subregister definitions around, avoid this by splitting them to 1174 // separate vregs before. Splitting can also improve reg. allocation quality. 1175 addPass(&RenameIndependentSubregsID); 1176 1177 // PreRA instruction scheduling. 1178 addPass(&MachineSchedulerID); 1179 1180 if (addRegAssignmentOptimized()) { 1181 // Allow targets to expand pseudo instructions depending on the choice of 1182 // registers before MachineCopyPropagation. 1183 addPostRewrite(); 1184 1185 // Copy propagate to forward register uses and try to eliminate COPYs that 1186 // were not coalesced. 1187 addPass(&MachineCopyPropagationID); 1188 1189 // Run post-ra machine LICM to hoist reloads / remats. 1190 // 1191 // FIXME: can this move into MachineLateOptimization? 1192 addPass(&MachineLICMID); 1193 } 1194 } 1195 1196 //===---------------------------------------------------------------------===// 1197 /// Post RegAlloc Pass Configuration 1198 //===---------------------------------------------------------------------===// 1199 1200 /// Add passes that optimize machine instructions after register allocation. 1201 void TargetPassConfig::addMachineLateOptimization() { 1202 // Branch folding must be run after regalloc and prolog/epilog insertion. 1203 addPass(&BranchFolderPassID); 1204 1205 // Tail duplication. 1206 // Note that duplicating tail just increases code size and degrades 1207 // performance for targets that require Structured Control Flow. 1208 // In addition it can also make CFG irreducible. Thus we disable it. 1209 if (!TM->requiresStructuredCFG()) 1210 addPass(&TailDuplicateID); 1211 1212 // Copy propagation. 1213 addPass(&MachineCopyPropagationID); 1214 } 1215 1216 /// Add standard GC passes. 1217 bool TargetPassConfig::addGCPasses() { 1218 addPass(&GCMachineCodeAnalysisID, false); 1219 return true; 1220 } 1221 1222 /// Add standard basic block placement passes. 1223 void TargetPassConfig::addBlockPlacement() { 1224 if (addPass(&MachineBlockPlacementID)) { 1225 // Run a separate pass to collect block placement statistics. 1226 if (EnableBlockPlacementStats) 1227 addPass(&MachineBlockPlacementStatsID); 1228 } 1229 } 1230 1231 //===---------------------------------------------------------------------===// 1232 /// GlobalISel Configuration 1233 //===---------------------------------------------------------------------===// 1234 bool TargetPassConfig::isGlobalISelAbortEnabled() const { 1235 return TM->Options.GlobalISelAbort == GlobalISelAbortMode::Enable; 1236 } 1237 1238 bool TargetPassConfig::reportDiagnosticWhenGlobalISelFallback() const { 1239 return TM->Options.GlobalISelAbort == GlobalISelAbortMode::DisableWithDiag; 1240 } 1241 1242 bool TargetPassConfig::isGISelCSEEnabled() const { 1243 return true; 1244 } 1245 1246 std::unique_ptr<CSEConfigBase> TargetPassConfig::getCSEConfig() const { 1247 return std::make_unique<CSEConfigBase>(); 1248 } 1249