AsmPrinter.cpp revision 36b56886974eae4f9c5ebc96befd3e7bfe5de338
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the AsmPrinter class. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "asm-printer" 15#include "llvm/CodeGen/AsmPrinter.h" 16#include "DwarfDebug.h" 17#include "DwarfException.h" 18#include "WinCodeViewLineTables.h" 19#include "llvm/ADT/SmallString.h" 20#include "llvm/ADT/Statistic.h" 21#include "llvm/Analysis/ConstantFolding.h" 22#include "llvm/CodeGen/GCMetadataPrinter.h" 23#include "llvm/CodeGen/MachineConstantPool.h" 24#include "llvm/CodeGen/MachineFrameInfo.h" 25#include "llvm/CodeGen/MachineFunction.h" 26#include "llvm/CodeGen/MachineInstrBundle.h" 27#include "llvm/CodeGen/MachineJumpTableInfo.h" 28#include "llvm/CodeGen/MachineLoopInfo.h" 29#include "llvm/CodeGen/MachineModuleInfo.h" 30#include "llvm/IR/DataLayout.h" 31#include "llvm/IR/DebugInfo.h" 32#include "llvm/IR/Mangler.h" 33#include "llvm/IR/Module.h" 34#include "llvm/IR/Operator.h" 35#include "llvm/MC/MCAsmInfo.h" 36#include "llvm/MC/MCContext.h" 37#include "llvm/MC/MCExpr.h" 38#include "llvm/MC/MCInst.h" 39#include "llvm/MC/MCSection.h" 40#include "llvm/MC/MCStreamer.h" 41#include "llvm/MC/MCSymbol.h" 42#include "llvm/Support/ErrorHandling.h" 43#include "llvm/Support/Format.h" 44#include "llvm/Support/MathExtras.h" 45#include "llvm/Support/Timer.h" 46#include "llvm/Target/TargetFrameLowering.h" 47#include "llvm/Target/TargetInstrInfo.h" 48#include "llvm/Target/TargetLowering.h" 49#include "llvm/Target/TargetLoweringObjectFile.h" 50#include "llvm/Target/TargetOptions.h" 51#include "llvm/Target/TargetRegisterInfo.h" 52#include "llvm/Target/TargetSubtargetInfo.h" 53#include "llvm/Transforms/Utils/GlobalStatus.h" 54using namespace llvm; 55 56static const char *const DWARFGroupName = "DWARF Emission"; 57static const char *const DbgTimerName = "Debug Info Emission"; 58static const char *const EHTimerName = "DWARF Exception Writer"; 59static const char *const CodeViewLineTablesGroupName = "CodeView Line Tables"; 60 61STATISTIC(EmittedInsts, "Number of machine instrs printed"); 62 63char AsmPrinter::ID = 0; 64 65typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 66static gcp_map_type &getGCMap(void *&P) { 67 if (P == 0) 68 P = new gcp_map_type(); 69 return *(gcp_map_type*)P; 70} 71 72 73/// getGVAlignmentLog2 - Return the alignment to use for the specified global 74/// value in log2 form. This rounds up to the preferred alignment if possible 75/// and legal. 76static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD, 77 unsigned InBits = 0) { 78 unsigned NumBits = 0; 79 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 80 NumBits = TD.getPreferredAlignmentLog(GVar); 81 82 // If InBits is specified, round it to it. 83 if (InBits > NumBits) 84 NumBits = InBits; 85 86 // If the GV has a specified alignment, take it into account. 87 if (GV->getAlignment() == 0) 88 return NumBits; 89 90 unsigned GVAlign = Log2_32(GV->getAlignment()); 91 92 // If the GVAlign is larger than NumBits, or if we are required to obey 93 // NumBits because the GV has an assigned section, obey it. 94 if (GVAlign > NumBits || GV->hasSection()) 95 NumBits = GVAlign; 96 return NumBits; 97} 98 99AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 100 : MachineFunctionPass(ID), 101 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()), 102 OutContext(Streamer.getContext()), 103 OutStreamer(Streamer), 104 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 105 DD = 0; MMI = 0; LI = 0; MF = 0; 106 CurrentFnSym = CurrentFnSymForSize = 0; 107 GCMetadataPrinters = 0; 108 VerboseAsm = Streamer.isVerboseAsm(); 109} 110 111AsmPrinter::~AsmPrinter() { 112 assert(DD == 0 && Handlers.empty() && "Debug/EH info didn't get finalized"); 113 114 if (GCMetadataPrinters != 0) { 115 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 116 117 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 118 delete I->second; 119 delete &GCMap; 120 GCMetadataPrinters = 0; 121 } 122 123 delete &OutStreamer; 124} 125 126/// getFunctionNumber - Return a unique ID for the current function. 127/// 128unsigned AsmPrinter::getFunctionNumber() const { 129 return MF->getFunctionNumber(); 130} 131 132const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 133 return TM.getTargetLowering()->getObjFileLowering(); 134} 135 136/// getDataLayout - Return information about data layout. 137const DataLayout &AsmPrinter::getDataLayout() const { 138 return *TM.getDataLayout(); 139} 140 141const MCSubtargetInfo &AsmPrinter::getSubtargetInfo() const { 142 return TM.getSubtarget<MCSubtargetInfo>(); 143} 144 145void AsmPrinter::EmitToStreamer(MCStreamer &S, const MCInst &Inst) { 146 S.EmitInstruction(Inst, getSubtargetInfo()); 147} 148 149StringRef AsmPrinter::getTargetTriple() const { 150 return TM.getTargetTriple(); 151} 152 153/// getCurrentSection() - Return the current section we are emitting to. 154const MCSection *AsmPrinter::getCurrentSection() const { 155 return OutStreamer.getCurrentSection().first; 156} 157 158 159 160void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 161 AU.setPreservesAll(); 162 MachineFunctionPass::getAnalysisUsage(AU); 163 AU.addRequired<MachineModuleInfo>(); 164 AU.addRequired<GCModuleInfo>(); 165 if (isVerbose()) 166 AU.addRequired<MachineLoopInfo>(); 167} 168 169bool AsmPrinter::doInitialization(Module &M) { 170 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 171 MMI->AnalyzeModule(M); 172 173 // Initialize TargetLoweringObjectFile. 174 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 175 .Initialize(OutContext, TM); 176 177 OutStreamer.InitSections(); 178 179 Mang = new Mangler(TM.getDataLayout()); 180 181 // Emit the version-min deplyment target directive if needed. 182 // 183 // FIXME: If we end up with a collection of these sorts of Darwin-specific 184 // or ELF-specific things, it may make sense to have a platform helper class 185 // that will work with the target helper class. For now keep it here, as the 186 // alternative is duplicated code in each of the target asm printers that 187 // use the directive, where it would need the same conditionalization 188 // anyway. 189 Triple TT(getTargetTriple()); 190 if (TT.isOSDarwin()) { 191 unsigned Major, Minor, Update; 192 TT.getOSVersion(Major, Minor, Update); 193 // If there is a version specified, Major will be non-zero. 194 if (Major) 195 OutStreamer.EmitVersionMin((TT.isMacOSX() ? 196 MCVM_OSXVersionMin : MCVM_IOSVersionMin), 197 Major, Minor, Update); 198 } 199 200 // Allow the target to emit any magic that it wants at the start of the file. 201 EmitStartOfAsmFile(M); 202 203 // Very minimal debug info. It is ignored if we emit actual debug info. If we 204 // don't, this at least helps the user find where a global came from. 205 if (MAI->hasSingleParameterDotFile()) { 206 // .file "foo.c" 207 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 208 } 209 210 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 211 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 212 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 213 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 214 MP->beginAssembly(*this); 215 216 // Emit module-level inline asm if it exists. 217 if (!M.getModuleInlineAsm().empty()) { 218 OutStreamer.AddComment("Start of file scope inline assembly"); 219 OutStreamer.AddBlankLine(); 220 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 221 OutStreamer.AddComment("End of file scope inline assembly"); 222 OutStreamer.AddBlankLine(); 223 } 224 225 if (MAI->doesSupportDebugInformation()) { 226 if (Triple(TM.getTargetTriple()).isKnownWindowsMSVCEnvironment()) { 227 Handlers.push_back(HandlerInfo(new WinCodeViewLineTables(this), 228 DbgTimerName, 229 CodeViewLineTablesGroupName)); 230 } else { 231 DD = new DwarfDebug(this, &M); 232 Handlers.push_back(HandlerInfo(DD, DbgTimerName, DWARFGroupName)); 233 } 234 } 235 236 DwarfException *DE = 0; 237 switch (MAI->getExceptionHandlingType()) { 238 case ExceptionHandling::None: 239 break; 240 case ExceptionHandling::SjLj: 241 case ExceptionHandling::DwarfCFI: 242 DE = new DwarfCFIException(this); 243 break; 244 case ExceptionHandling::ARM: 245 DE = new ARMException(this); 246 break; 247 case ExceptionHandling::Win64: 248 DE = new Win64Exception(this); 249 break; 250 } 251 if (DE) 252 Handlers.push_back(HandlerInfo(DE, EHTimerName, DWARFGroupName)); 253 return false; 254} 255 256static bool canBeHidden(const GlobalValue *GV, const MCAsmInfo &MAI) { 257 GlobalValue::LinkageTypes Linkage = GV->getLinkage(); 258 if (Linkage != GlobalValue::LinkOnceODRLinkage) 259 return false; 260 261 if (!MAI.hasWeakDefCanBeHiddenDirective()) 262 return false; 263 264 if (GV->hasUnnamedAddr()) 265 return true; 266 267 // This is only used for MachO, so right now it doesn't really matter how 268 // we handle alias. Revisit this once the MachO linker implements aliases. 269 if (isa<GlobalAlias>(GV)) 270 return false; 271 272 // If it is a non constant variable, it needs to be uniqued across shared 273 // objects. 274 if (const GlobalVariable *Var = dyn_cast<GlobalVariable>(GV)) { 275 if (!Var->isConstant()) 276 return false; 277 } 278 279 GlobalStatus GS; 280 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared) 281 return true; 282 283 return false; 284} 285 286void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const { 287 GlobalValue::LinkageTypes Linkage = GV->getLinkage(); 288 switch (Linkage) { 289 case GlobalValue::CommonLinkage: 290 case GlobalValue::LinkOnceAnyLinkage: 291 case GlobalValue::LinkOnceODRLinkage: 292 case GlobalValue::WeakAnyLinkage: 293 case GlobalValue::WeakODRLinkage: 294 if (MAI->hasWeakDefDirective()) { 295 // .globl _foo 296 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 297 298 if (!canBeHidden(GV, *MAI)) 299 // .weak_definition _foo 300 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 301 else 302 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 303 } else if (MAI->hasLinkOnceDirective()) { 304 // .globl _foo 305 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 306 //NOTE: linkonce is handled by the section the symbol was assigned to. 307 } else { 308 // .weak _foo 309 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 310 } 311 return; 312 case GlobalValue::AppendingLinkage: 313 // FIXME: appending linkage variables should go into a section of 314 // their name or something. For now, just emit them as external. 315 case GlobalValue::ExternalLinkage: 316 // If external or appending, declare as a global symbol. 317 // .globl _foo 318 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 319 return; 320 case GlobalValue::PrivateLinkage: 321 case GlobalValue::InternalLinkage: 322 return; 323 case GlobalValue::AvailableExternallyLinkage: 324 llvm_unreachable("Should never emit this"); 325 case GlobalValue::ExternalWeakLinkage: 326 llvm_unreachable("Don't know how to emit these"); 327 } 328 llvm_unreachable("Unknown linkage type!"); 329} 330 331void AsmPrinter::getNameWithPrefix(SmallVectorImpl<char> &Name, 332 const GlobalValue *GV) const { 333 TM.getNameWithPrefix(Name, GV, *Mang); 334} 335 336MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const { 337 return TM.getSymbol(GV, *Mang); 338} 339 340/// EmitGlobalVariable - Emit the specified global variable to the .s file. 341void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 342 if (GV->hasInitializer()) { 343 // Check to see if this is a special global used by LLVM, if so, emit it. 344 if (EmitSpecialLLVMGlobal(GV)) 345 return; 346 347 if (isVerbose()) { 348 GV->printAsOperand(OutStreamer.GetCommentOS(), 349 /*PrintType=*/false, GV->getParent()); 350 OutStreamer.GetCommentOS() << '\n'; 351 } 352 } 353 354 MCSymbol *GVSym = getSymbol(GV); 355 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration()); 356 357 if (!GV->hasInitializer()) // External globals require no extra code. 358 return; 359 360 if (MAI->hasDotTypeDotSizeDirective()) 361 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 362 363 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 364 365 const DataLayout *DL = TM.getDataLayout(); 366 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType()); 367 368 // If the alignment is specified, we *must* obey it. Overaligning a global 369 // with a specified alignment is a prompt way to break globals emitted to 370 // sections and expected to be contiguous (e.g. ObjC metadata). 371 unsigned AlignLog = getGVAlignmentLog2(GV, *DL); 372 373 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) { 374 const HandlerInfo &OI = Handlers[I]; 375 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled); 376 OI.Handler->setSymbolSize(GVSym, Size); 377 } 378 379 // Handle common and BSS local symbols (.lcomm). 380 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 381 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 382 unsigned Align = 1 << AlignLog; 383 384 // Handle common symbols. 385 if (GVKind.isCommon()) { 386 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 387 Align = 0; 388 389 // .comm _foo, 42, 4 390 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 391 return; 392 } 393 394 // Handle local BSS symbols. 395 if (MAI->hasMachoZeroFillDirective()) { 396 const MCSection *TheSection = 397 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM); 398 // .zerofill __DATA, __bss, _foo, 400, 5 399 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align); 400 return; 401 } 402 403 // Use .lcomm only if it supports user-specified alignment. 404 // Otherwise, while it would still be correct to use .lcomm in some 405 // cases (e.g. when Align == 1), the external assembler might enfore 406 // some -unknown- default alignment behavior, which could cause 407 // spurious differences between external and integrated assembler. 408 // Prefer to simply fall back to .local / .comm in this case. 409 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) { 410 // .lcomm _foo, 42 411 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align); 412 return; 413 } 414 415 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 416 Align = 0; 417 418 // .local _foo 419 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 420 // .comm _foo, 42, 4 421 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 422 return; 423 } 424 425 const MCSection *TheSection = 426 getObjFileLowering().SectionForGlobal(GV, GVKind, *Mang, TM); 427 428 // Handle the zerofill directive on darwin, which is a special form of BSS 429 // emission. 430 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 431 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 432 433 // .globl _foo 434 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 435 // .zerofill __DATA, __common, _foo, 400, 5 436 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 437 return; 438 } 439 440 // Handle thread local data for mach-o which requires us to output an 441 // additional structure of data and mangle the original symbol so that we 442 // can reference it later. 443 // 444 // TODO: This should become an "emit thread local global" method on TLOF. 445 // All of this macho specific stuff should be sunk down into TLOFMachO and 446 // stuff like "TLSExtraDataSection" should no longer be part of the parent 447 // TLOF class. This will also make it more obvious that stuff like 448 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 449 // specific code. 450 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 451 // Emit the .tbss symbol 452 MCSymbol *MangSym = 453 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 454 455 if (GVKind.isThreadBSS()) { 456 TheSection = getObjFileLowering().getTLSBSSSection(); 457 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 458 } else if (GVKind.isThreadData()) { 459 OutStreamer.SwitchSection(TheSection); 460 461 EmitAlignment(AlignLog, GV); 462 OutStreamer.EmitLabel(MangSym); 463 464 EmitGlobalConstant(GV->getInitializer()); 465 } 466 467 OutStreamer.AddBlankLine(); 468 469 // Emit the variable struct for the runtime. 470 const MCSection *TLVSect 471 = getObjFileLowering().getTLSExtraDataSection(); 472 473 OutStreamer.SwitchSection(TLVSect); 474 // Emit the linkage here. 475 EmitLinkage(GV, GVSym); 476 OutStreamer.EmitLabel(GVSym); 477 478 // Three pointers in size: 479 // - __tlv_bootstrap - used to make sure support exists 480 // - spare pointer, used when mapped by the runtime 481 // - pointer to mangled symbol above with initializer 482 unsigned PtrSize = DL->getPointerTypeSize(GV->getType()); 483 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 484 PtrSize); 485 OutStreamer.EmitIntValue(0, PtrSize); 486 OutStreamer.EmitSymbolValue(MangSym, PtrSize); 487 488 OutStreamer.AddBlankLine(); 489 return; 490 } 491 492 OutStreamer.SwitchSection(TheSection); 493 494 EmitLinkage(GV, GVSym); 495 EmitAlignment(AlignLog, GV); 496 497 OutStreamer.EmitLabel(GVSym); 498 499 EmitGlobalConstant(GV->getInitializer()); 500 501 if (MAI->hasDotTypeDotSizeDirective()) 502 // .size foo, 42 503 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 504 505 OutStreamer.AddBlankLine(); 506} 507 508/// EmitFunctionHeader - This method emits the header for the current 509/// function. 510void AsmPrinter::EmitFunctionHeader() { 511 // Print out constants referenced by the function 512 EmitConstantPool(); 513 514 // Print the 'header' of function. 515 const Function *F = MF->getFunction(); 516 517 OutStreamer.SwitchSection( 518 getObjFileLowering().SectionForGlobal(F, *Mang, TM)); 519 EmitVisibility(CurrentFnSym, F->getVisibility()); 520 521 EmitLinkage(F, CurrentFnSym); 522 EmitAlignment(MF->getAlignment(), F); 523 524 if (MAI->hasDotTypeDotSizeDirective()) 525 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 526 527 if (isVerbose()) { 528 F->printAsOperand(OutStreamer.GetCommentOS(), 529 /*PrintType=*/false, F->getParent()); 530 OutStreamer.GetCommentOS() << '\n'; 531 } 532 533 // Emit the CurrentFnSym. This is a virtual function to allow targets to 534 // do their wild and crazy things as required. 535 EmitFunctionEntryLabel(); 536 537 // If the function had address-taken blocks that got deleted, then we have 538 // references to the dangling symbols. Emit them at the start of the function 539 // so that we don't get references to undefined symbols. 540 std::vector<MCSymbol*> DeadBlockSyms; 541 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 542 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 543 OutStreamer.AddComment("Address taken block that was later removed"); 544 OutStreamer.EmitLabel(DeadBlockSyms[i]); 545 } 546 547 // Emit pre-function debug and/or EH information. 548 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) { 549 const HandlerInfo &OI = Handlers[I]; 550 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled); 551 OI.Handler->beginFunction(MF); 552 } 553 554 // Emit the prefix data. 555 if (F->hasPrefixData()) 556 EmitGlobalConstant(F->getPrefixData()); 557} 558 559/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 560/// function. This can be overridden by targets as required to do custom stuff. 561void AsmPrinter::EmitFunctionEntryLabel() { 562 // The function label could have already been emitted if two symbols end up 563 // conflicting due to asm renaming. Detect this and emit an error. 564 if (CurrentFnSym->isUndefined()) 565 return OutStreamer.EmitLabel(CurrentFnSym); 566 567 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 568 "' label emitted multiple times to assembly file"); 569} 570 571/// emitComments - Pretty-print comments for instructions. 572static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 573 const MachineFunction *MF = MI.getParent()->getParent(); 574 const TargetMachine &TM = MF->getTarget(); 575 576 // Check for spills and reloads 577 int FI; 578 579 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 580 581 // We assume a single instruction only has a spill or reload, not 582 // both. 583 const MachineMemOperand *MMO; 584 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 585 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 586 MMO = *MI.memoperands_begin(); 587 CommentOS << MMO->getSize() << "-byte Reload\n"; 588 } 589 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 590 if (FrameInfo->isSpillSlotObjectIndex(FI)) 591 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 592 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 593 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 594 MMO = *MI.memoperands_begin(); 595 CommentOS << MMO->getSize() << "-byte Spill\n"; 596 } 597 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 598 if (FrameInfo->isSpillSlotObjectIndex(FI)) 599 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 600 } 601 602 // Check for spill-induced copies 603 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 604 CommentOS << " Reload Reuse\n"; 605} 606 607/// emitImplicitDef - This method emits the specified machine instruction 608/// that is an implicit def. 609void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const { 610 unsigned RegNo = MI->getOperand(0).getReg(); 611 OutStreamer.AddComment(Twine("implicit-def: ") + 612 TM.getRegisterInfo()->getName(RegNo)); 613 OutStreamer.AddBlankLine(); 614} 615 616static void emitKill(const MachineInstr *MI, AsmPrinter &AP) { 617 std::string Str = "kill:"; 618 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 619 const MachineOperand &Op = MI->getOperand(i); 620 assert(Op.isReg() && "KILL instruction must have only register operands"); 621 Str += ' '; 622 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 623 Str += (Op.isDef() ? "<def>" : "<kill>"); 624 } 625 AP.OutStreamer.AddComment(Str); 626 AP.OutStreamer.AddBlankLine(); 627} 628 629/// emitDebugValueComment - This method handles the target-independent form 630/// of DBG_VALUE, returning true if it was able to do so. A false return 631/// means the target will need to handle MI in EmitInstruction. 632static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 633 // This code handles only the 3-operand target-independent form. 634 if (MI->getNumOperands() != 3) 635 return false; 636 637 SmallString<128> Str; 638 raw_svector_ostream OS(Str); 639 OS << "DEBUG_VALUE: "; 640 641 DIVariable V(MI->getOperand(2).getMetadata()); 642 if (V.getContext().isSubprogram()) { 643 StringRef Name = DISubprogram(V.getContext()).getDisplayName(); 644 if (!Name.empty()) 645 OS << Name << ":"; 646 } 647 OS << V.getName() << " <- "; 648 649 // The second operand is only an offset if it's an immediate. 650 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm(); 651 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0; 652 653 // Register or immediate value. Register 0 means undef. 654 if (MI->getOperand(0).isFPImm()) { 655 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 656 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 657 OS << (double)APF.convertToFloat(); 658 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 659 OS << APF.convertToDouble(); 660 } else { 661 // There is no good way to print long double. Convert a copy to 662 // double. Ah well, it's only a comment. 663 bool ignored; 664 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 665 &ignored); 666 OS << "(long double) " << APF.convertToDouble(); 667 } 668 } else if (MI->getOperand(0).isImm()) { 669 OS << MI->getOperand(0).getImm(); 670 } else if (MI->getOperand(0).isCImm()) { 671 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/); 672 } else { 673 unsigned Reg; 674 if (MI->getOperand(0).isReg()) { 675 Reg = MI->getOperand(0).getReg(); 676 } else { 677 assert(MI->getOperand(0).isFI() && "Unknown operand type"); 678 const TargetFrameLowering *TFI = AP.TM.getFrameLowering(); 679 Offset += TFI->getFrameIndexReference(*AP.MF, 680 MI->getOperand(0).getIndex(), Reg); 681 Deref = true; 682 } 683 if (Reg == 0) { 684 // Suppress offset, it is not meaningful here. 685 OS << "undef"; 686 // NOTE: Want this comment at start of line, don't emit with AddComment. 687 AP.OutStreamer.emitRawComment(OS.str()); 688 return true; 689 } 690 if (Deref) 691 OS << '['; 692 OS << AP.TM.getRegisterInfo()->getName(Reg); 693 } 694 695 if (Deref) 696 OS << '+' << Offset << ']'; 697 698 // NOTE: Want this comment at start of line, don't emit with AddComment. 699 AP.OutStreamer.emitRawComment(OS.str()); 700 return true; 701} 702 703AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() { 704 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI && 705 MF->getFunction()->needsUnwindTableEntry()) 706 return CFI_M_EH; 707 708 if (MMI->hasDebugInfo()) 709 return CFI_M_Debug; 710 711 return CFI_M_None; 712} 713 714bool AsmPrinter::needsSEHMoves() { 715 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 && 716 MF->getFunction()->needsUnwindTableEntry(); 717} 718 719void AsmPrinter::emitCFIInstruction(const MachineInstr &MI) { 720 ExceptionHandling::ExceptionsType ExceptionHandlingType = 721 MAI->getExceptionHandlingType(); 722 if (ExceptionHandlingType != ExceptionHandling::DwarfCFI && 723 ExceptionHandlingType != ExceptionHandling::ARM) 724 return; 725 726 if (needsCFIMoves() == CFI_M_None) 727 return; 728 729 if (MMI->getCompactUnwindEncoding() != 0) 730 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding()); 731 732 const MachineModuleInfo &MMI = MF->getMMI(); 733 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions(); 734 unsigned CFIIndex = MI.getOperand(0).getCFIIndex(); 735 const MCCFIInstruction &CFI = Instrs[CFIIndex]; 736 emitCFIInstruction(CFI); 737} 738 739/// EmitFunctionBody - This method emits the body and trailer for a 740/// function. 741void AsmPrinter::EmitFunctionBody() { 742 // Emit target-specific gunk before the function body. 743 EmitFunctionBodyStart(); 744 745 bool ShouldPrintDebugScopes = MMI->hasDebugInfo(); 746 747 // Print out code for the function. 748 bool HasAnyRealCode = false; 749 const MachineInstr *LastMI = 0; 750 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 751 I != E; ++I) { 752 // Print a label for the basic block. 753 EmitBasicBlockStart(I); 754 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 755 II != IE; ++II) { 756 LastMI = II; 757 758 // Print the assembly for the instruction. 759 if (!II->isPosition() && !II->isImplicitDef() && !II->isKill() && 760 !II->isDebugValue()) { 761 HasAnyRealCode = true; 762 ++EmittedInsts; 763 } 764 765 if (ShouldPrintDebugScopes) { 766 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) { 767 const HandlerInfo &OI = Handlers[III]; 768 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, 769 TimePassesIsEnabled); 770 OI.Handler->beginInstruction(II); 771 } 772 } 773 774 if (isVerbose()) 775 emitComments(*II, OutStreamer.GetCommentOS()); 776 777 switch (II->getOpcode()) { 778 case TargetOpcode::CFI_INSTRUCTION: 779 emitCFIInstruction(*II); 780 break; 781 782 case TargetOpcode::EH_LABEL: 783 case TargetOpcode::GC_LABEL: 784 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 785 break; 786 case TargetOpcode::INLINEASM: 787 EmitInlineAsm(II); 788 break; 789 case TargetOpcode::DBG_VALUE: 790 if (isVerbose()) { 791 if (!emitDebugValueComment(II, *this)) 792 EmitInstruction(II); 793 } 794 break; 795 case TargetOpcode::IMPLICIT_DEF: 796 if (isVerbose()) emitImplicitDef(II); 797 break; 798 case TargetOpcode::KILL: 799 if (isVerbose()) emitKill(II, *this); 800 break; 801 default: 802 EmitInstruction(II); 803 break; 804 } 805 806 if (ShouldPrintDebugScopes) { 807 for (unsigned III = 0, EEE = Handlers.size(); III != EEE; ++III) { 808 const HandlerInfo &OI = Handlers[III]; 809 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, 810 TimePassesIsEnabled); 811 OI.Handler->endInstruction(); 812 } 813 } 814 } 815 } 816 817 // If the last instruction was a prolog label, then we have a situation where 818 // we emitted a prolog but no function body. This results in the ending prolog 819 // label equaling the end of function label and an invalid "row" in the 820 // FDE. We need to emit a noop in this situation so that the FDE's rows are 821 // valid. 822 bool RequiresNoop = LastMI && LastMI->isCFIInstruction(); 823 824 // If the function is empty and the object file uses .subsections_via_symbols, 825 // then we need to emit *something* to the function body to prevent the 826 // labels from collapsing together. Just emit a noop. 827 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 828 MCInst Noop; 829 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 830 if (Noop.getOpcode()) { 831 OutStreamer.AddComment("avoids zero-length function"); 832 OutStreamer.EmitInstruction(Noop, getSubtargetInfo()); 833 } else // Target not mc-ized yet. 834 OutStreamer.EmitRawText(StringRef("\tnop\n")); 835 } 836 837 const Function *F = MF->getFunction(); 838 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) { 839 const BasicBlock *BB = i; 840 if (!BB->hasAddressTaken()) 841 continue; 842 MCSymbol *Sym = GetBlockAddressSymbol(BB); 843 if (Sym->isDefined()) 844 continue; 845 OutStreamer.AddComment("Address of block that was removed by CodeGen"); 846 OutStreamer.EmitLabel(Sym); 847 } 848 849 // Emit target-specific gunk after the function body. 850 EmitFunctionBodyEnd(); 851 852 // If the target wants a .size directive for the size of the function, emit 853 // it. 854 if (MAI->hasDotTypeDotSizeDirective()) { 855 // Create a symbol for the end of function, so we can get the size as 856 // difference between the function label and the temp label. 857 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 858 OutStreamer.EmitLabel(FnEndLabel); 859 860 const MCExpr *SizeExp = 861 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 862 MCSymbolRefExpr::Create(CurrentFnSymForSize, 863 OutContext), 864 OutContext); 865 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 866 } 867 868 // Emit post-function debug and/or EH information. 869 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) { 870 const HandlerInfo &OI = Handlers[I]; 871 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, TimePassesIsEnabled); 872 OI.Handler->endFunction(MF); 873 } 874 MMI->EndFunction(); 875 876 // Print out jump tables referenced by the function. 877 EmitJumpTableInfo(); 878 879 OutStreamer.AddBlankLine(); 880} 881 882bool AsmPrinter::doFinalization(Module &M) { 883 // Emit global variables. 884 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 885 I != E; ++I) 886 EmitGlobalVariable(I); 887 888 // Emit visibility info for declarations 889 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 890 const Function &F = *I; 891 if (!F.isDeclaration()) 892 continue; 893 GlobalValue::VisibilityTypes V = F.getVisibility(); 894 if (V == GlobalValue::DefaultVisibility) 895 continue; 896 897 MCSymbol *Name = getSymbol(&F); 898 EmitVisibility(Name, V, false); 899 } 900 901 // Emit module flags. 902 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags; 903 M.getModuleFlagsMetadata(ModuleFlags); 904 if (!ModuleFlags.empty()) 905 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, *Mang, TM); 906 907 // Make sure we wrote out everything we need. 908 OutStreamer.Flush(); 909 910 // Finalize debug and EH information. 911 for (unsigned I = 0, E = Handlers.size(); I != E; ++I) { 912 const HandlerInfo &OI = Handlers[I]; 913 NamedRegionTimer T(OI.TimerName, OI.TimerGroupName, 914 TimePassesIsEnabled); 915 OI.Handler->endModule(); 916 delete OI.Handler; 917 } 918 Handlers.clear(); 919 DD = 0; 920 921 // If the target wants to know about weak references, print them all. 922 if (MAI->getWeakRefDirective()) { 923 // FIXME: This is not lazy, it would be nice to only print weak references 924 // to stuff that is actually used. Note that doing so would require targets 925 // to notice uses in operands (due to constant exprs etc). This should 926 // happen with the MC stuff eventually. 927 928 // Print out module-level global variables here. 929 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 930 I != E; ++I) { 931 if (!I->hasExternalWeakLinkage()) continue; 932 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference); 933 } 934 935 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 936 if (!I->hasExternalWeakLinkage()) continue; 937 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference); 938 } 939 } 940 941 if (MAI->hasSetDirective()) { 942 OutStreamer.AddBlankLine(); 943 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 944 I != E; ++I) { 945 MCSymbol *Name = getSymbol(I); 946 947 const GlobalValue *GV = I->getAliasedGlobal(); 948 assert(!GV->isDeclaration()); 949 MCSymbol *Target = getSymbol(GV); 950 951 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 952 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 953 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage()) 954 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 955 else 956 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 957 958 EmitVisibility(Name, I->getVisibility()); 959 960 // Emit the directives as assignments aka .set: 961 OutStreamer.EmitAssignment(Name, 962 MCSymbolRefExpr::Create(Target, OutContext)); 963 } 964 } 965 966 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 967 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 968 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 969 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 970 MP->finishAssembly(*this); 971 972 // Emit llvm.ident metadata in an '.ident' directive. 973 EmitModuleIdents(M); 974 975 // If we don't have any trampolines, then we don't require stack memory 976 // to be executable. Some targets have a directive to declare this. 977 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 978 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 979 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 980 OutStreamer.SwitchSection(S); 981 982 // Allow the target to emit any magic that it wants at the end of the file, 983 // after everything else has gone out. 984 EmitEndOfAsmFile(M); 985 986 delete Mang; Mang = 0; 987 MMI = 0; 988 989 OutStreamer.Finish(); 990 OutStreamer.reset(); 991 992 return false; 993} 994 995void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 996 this->MF = &MF; 997 // Get the function symbol. 998 CurrentFnSym = getSymbol(MF.getFunction()); 999 CurrentFnSymForSize = CurrentFnSym; 1000 1001 if (isVerbose()) 1002 LI = &getAnalysis<MachineLoopInfo>(); 1003} 1004 1005namespace { 1006 // SectionCPs - Keep track the alignment, constpool entries per Section. 1007 struct SectionCPs { 1008 const MCSection *S; 1009 unsigned Alignment; 1010 SmallVector<unsigned, 4> CPEs; 1011 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 1012 }; 1013} 1014 1015/// EmitConstantPool - Print to the current output stream assembly 1016/// representations of the constants in the constant pool MCP. This is 1017/// used to print out constants which have been "spilled to memory" by 1018/// the code generator. 1019/// 1020void AsmPrinter::EmitConstantPool() { 1021 const MachineConstantPool *MCP = MF->getConstantPool(); 1022 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 1023 if (CP.empty()) return; 1024 1025 // Calculate sections for constant pool entries. We collect entries to go into 1026 // the same section together to reduce amount of section switch statements. 1027 SmallVector<SectionCPs, 4> CPSections; 1028 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 1029 const MachineConstantPoolEntry &CPE = CP[i]; 1030 unsigned Align = CPE.getAlignment(); 1031 1032 SectionKind Kind; 1033 switch (CPE.getRelocationInfo()) { 1034 default: llvm_unreachable("Unknown section kind"); 1035 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 1036 case 1: 1037 Kind = SectionKind::getReadOnlyWithRelLocal(); 1038 break; 1039 case 0: 1040 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) { 1041 case 4: Kind = SectionKind::getMergeableConst4(); break; 1042 case 8: Kind = SectionKind::getMergeableConst8(); break; 1043 case 16: Kind = SectionKind::getMergeableConst16();break; 1044 default: Kind = SectionKind::getMergeableConst(); break; 1045 } 1046 } 1047 1048 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 1049 1050 // The number of sections are small, just do a linear search from the 1051 // last section to the first. 1052 bool Found = false; 1053 unsigned SecIdx = CPSections.size(); 1054 while (SecIdx != 0) { 1055 if (CPSections[--SecIdx].S == S) { 1056 Found = true; 1057 break; 1058 } 1059 } 1060 if (!Found) { 1061 SecIdx = CPSections.size(); 1062 CPSections.push_back(SectionCPs(S, Align)); 1063 } 1064 1065 if (Align > CPSections[SecIdx].Alignment) 1066 CPSections[SecIdx].Alignment = Align; 1067 CPSections[SecIdx].CPEs.push_back(i); 1068 } 1069 1070 // Now print stuff into the calculated sections. 1071 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 1072 OutStreamer.SwitchSection(CPSections[i].S); 1073 EmitAlignment(Log2_32(CPSections[i].Alignment)); 1074 1075 unsigned Offset = 0; 1076 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 1077 unsigned CPI = CPSections[i].CPEs[j]; 1078 MachineConstantPoolEntry CPE = CP[CPI]; 1079 1080 // Emit inter-object padding for alignment. 1081 unsigned AlignMask = CPE.getAlignment() - 1; 1082 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 1083 OutStreamer.EmitZeros(NewOffset - Offset); 1084 1085 Type *Ty = CPE.getType(); 1086 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty); 1087 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 1088 1089 if (CPE.isMachineConstantPoolEntry()) 1090 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 1091 else 1092 EmitGlobalConstant(CPE.Val.ConstVal); 1093 } 1094 } 1095} 1096 1097/// EmitJumpTableInfo - Print assembly representations of the jump tables used 1098/// by the current function to the current output stream. 1099/// 1100void AsmPrinter::EmitJumpTableInfo() { 1101 const DataLayout *DL = MF->getTarget().getDataLayout(); 1102 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1103 if (MJTI == 0) return; 1104 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1105 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1106 if (JT.empty()) return; 1107 1108 // Pick the directive to use to print the jump table entries, and switch to 1109 // the appropriate section. 1110 const Function *F = MF->getFunction(); 1111 bool JTInDiffSection = false; 1112 if (// In PIC mode, we need to emit the jump table to the same section as the 1113 // function body itself, otherwise the label differences won't make sense. 1114 // FIXME: Need a better predicate for this: what about custom entries? 1115 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1116 // We should also do if the section name is NULL or function is declared 1117 // in discardable section 1118 // FIXME: this isn't the right predicate, should be based on the MCSection 1119 // for the function. 1120 F->isWeakForLinker()) { 1121 OutStreamer.SwitchSection( 1122 getObjFileLowering().SectionForGlobal(F, *Mang, TM)); 1123 } else { 1124 // Otherwise, drop it in the readonly section. 1125 const MCSection *ReadOnlySection = 1126 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1127 OutStreamer.SwitchSection(ReadOnlySection); 1128 JTInDiffSection = true; 1129 } 1130 1131 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout()))); 1132 1133 // Jump tables in code sections are marked with a data_region directive 1134 // where that's supported. 1135 if (!JTInDiffSection) 1136 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32); 1137 1138 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1139 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1140 1141 // If this jump table was deleted, ignore it. 1142 if (JTBBs.empty()) continue; 1143 1144 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1145 // .set directive for each unique entry. This reduces the number of 1146 // relocations the assembler will generate for the jump table. 1147 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1148 MAI->hasSetDirective()) { 1149 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1150 const TargetLowering *TLI = TM.getTargetLowering(); 1151 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1152 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1153 const MachineBasicBlock *MBB = JTBBs[ii]; 1154 if (!EmittedSets.insert(MBB)) continue; 1155 1156 // .set LJTSet, LBB32-base 1157 const MCExpr *LHS = 1158 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1159 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1160 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1161 } 1162 } 1163 1164 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1165 // before each jump table. The first label is never referenced, but tells 1166 // the assembler and linker the extents of the jump table object. The 1167 // second label is actually referenced by the code. 1168 if (JTInDiffSection && DL->hasLinkerPrivateGlobalPrefix()) 1169 // FIXME: This doesn't have to have any specific name, just any randomly 1170 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1171 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1172 1173 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1174 1175 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1176 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1177 } 1178 if (!JTInDiffSection) 1179 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd); 1180} 1181 1182/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1183/// current stream. 1184void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1185 const MachineBasicBlock *MBB, 1186 unsigned UID) const { 1187 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1188 const MCExpr *Value = 0; 1189 switch (MJTI->getEntryKind()) { 1190 case MachineJumpTableInfo::EK_Inline: 1191 llvm_unreachable("Cannot emit EK_Inline jump table entry"); 1192 case MachineJumpTableInfo::EK_Custom32: 1193 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1194 OutContext); 1195 break; 1196 case MachineJumpTableInfo::EK_BlockAddress: 1197 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1198 // .word LBB123 1199 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1200 break; 1201 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1202 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1203 // with a relocation as gp-relative, e.g.: 1204 // .gprel32 LBB123 1205 MCSymbol *MBBSym = MBB->getSymbol(); 1206 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1207 return; 1208 } 1209 1210 case MachineJumpTableInfo::EK_GPRel64BlockAddress: { 1211 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded 1212 // with a relocation as gp-relative, e.g.: 1213 // .gpdword LBB123 1214 MCSymbol *MBBSym = MBB->getSymbol(); 1215 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1216 return; 1217 } 1218 1219 case MachineJumpTableInfo::EK_LabelDifference32: { 1220 // EK_LabelDifference32 - Each entry is the address of the block minus 1221 // the address of the jump table. This is used for PIC jump tables where 1222 // gprel32 is not supported. e.g.: 1223 // .word LBB123 - LJTI1_2 1224 // If the .set directive is supported, this is emitted as: 1225 // .set L4_5_set_123, LBB123 - LJTI1_2 1226 // .word L4_5_set_123 1227 1228 // If we have emitted set directives for the jump table entries, print 1229 // them rather than the entries themselves. If we're emitting PIC, then 1230 // emit the table entries as differences between two text section labels. 1231 if (MAI->hasSetDirective()) { 1232 // If we used .set, reference the .set's symbol. 1233 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1234 OutContext); 1235 break; 1236 } 1237 // Otherwise, use the difference as the jump table entry. 1238 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1239 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1240 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1241 break; 1242 } 1243 } 1244 1245 assert(Value && "Unknown entry kind!"); 1246 1247 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout()); 1248 OutStreamer.EmitValue(Value, EntrySize); 1249} 1250 1251 1252/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1253/// special global used by LLVM. If so, emit it and return true, otherwise 1254/// do nothing and return false. 1255bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1256 if (GV->getName() == "llvm.used") { 1257 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1258 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer())); 1259 return true; 1260 } 1261 1262 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1263 if (GV->getSection() == "llvm.metadata" || 1264 GV->hasAvailableExternallyLinkage()) 1265 return true; 1266 1267 if (!GV->hasAppendingLinkage()) return false; 1268 1269 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1270 1271 if (GV->getName() == "llvm.global_ctors") { 1272 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true); 1273 1274 if (TM.getRelocationModel() == Reloc::Static && 1275 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1276 StringRef Sym(".constructors_used"); 1277 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1278 MCSA_Reference); 1279 } 1280 return true; 1281 } 1282 1283 if (GV->getName() == "llvm.global_dtors") { 1284 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false); 1285 1286 if (TM.getRelocationModel() == Reloc::Static && 1287 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1288 StringRef Sym(".destructors_used"); 1289 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1290 MCSA_Reference); 1291 } 1292 return true; 1293 } 1294 1295 return false; 1296} 1297 1298/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1299/// global in the specified llvm.used list for which emitUsedDirectiveFor 1300/// is true, as being used with this directive. 1301void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) { 1302 // Should be an array of 'i8*'. 1303 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1304 const GlobalValue *GV = 1305 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1306 if (GV) 1307 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip); 1308 } 1309} 1310 1311/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init 1312/// priority. 1313void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) { 1314 // Should be an array of '{ int, void ()* }' structs. The first value is the 1315 // init priority. 1316 if (!isa<ConstantArray>(List)) return; 1317 1318 // Sanity check the structors list. 1319 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1320 if (!InitList) return; // Not an array! 1321 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType()); 1322 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs! 1323 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) || 1324 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr). 1325 1326 // Gather the structors in a form that's convenient for sorting by priority. 1327 typedef std::pair<unsigned, Constant *> Structor; 1328 SmallVector<Structor, 8> Structors; 1329 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1330 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i)); 1331 if (!CS) continue; // Malformed. 1332 if (CS->getOperand(1)->isNullValue()) 1333 break; // Found a null terminator, skip the rest. 1334 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0)); 1335 if (!Priority) continue; // Malformed. 1336 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535), 1337 CS->getOperand(1))); 1338 } 1339 1340 // Emit the function pointers in the target-specific order 1341 const DataLayout *DL = TM.getDataLayout(); 1342 unsigned Align = Log2_32(DL->getPointerPrefAlignment()); 1343 std::stable_sort(Structors.begin(), Structors.end(), less_first()); 1344 for (unsigned i = 0, e = Structors.size(); i != e; ++i) { 1345 const MCSection *OutputSection = 1346 (isCtor ? 1347 getObjFileLowering().getStaticCtorSection(Structors[i].first) : 1348 getObjFileLowering().getStaticDtorSection(Structors[i].first)); 1349 OutStreamer.SwitchSection(OutputSection); 1350 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection()) 1351 EmitAlignment(Align); 1352 EmitXXStructor(Structors[i].second); 1353 } 1354} 1355 1356void AsmPrinter::EmitModuleIdents(Module &M) { 1357 if (!MAI->hasIdentDirective()) 1358 return; 1359 1360 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) { 1361 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) { 1362 const MDNode *N = NMD->getOperand(i); 1363 assert(N->getNumOperands() == 1 && 1364 "llvm.ident metadata entry can have only one operand"); 1365 const MDString *S = cast<MDString>(N->getOperand(0)); 1366 OutStreamer.EmitIdent(S->getString()); 1367 } 1368 } 1369} 1370 1371//===--------------------------------------------------------------------===// 1372// Emission and print routines 1373// 1374 1375/// EmitInt8 - Emit a byte directive and value. 1376/// 1377void AsmPrinter::EmitInt8(int Value) const { 1378 OutStreamer.EmitIntValue(Value, 1); 1379} 1380 1381/// EmitInt16 - Emit a short directive and value. 1382/// 1383void AsmPrinter::EmitInt16(int Value) const { 1384 OutStreamer.EmitIntValue(Value, 2); 1385} 1386 1387/// EmitInt32 - Emit a long directive and value. 1388/// 1389void AsmPrinter::EmitInt32(int Value) const { 1390 OutStreamer.EmitIntValue(Value, 4); 1391} 1392 1393/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1394/// in bytes of the directive is specified by Size and Hi/Lo specify the 1395/// labels. This implicitly uses .set if it is available. 1396void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1397 unsigned Size) const { 1398 // Get the Hi-Lo expression. 1399 const MCExpr *Diff = 1400 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1401 MCSymbolRefExpr::Create(Lo, OutContext), 1402 OutContext); 1403 1404 if (!MAI->hasSetDirective()) { 1405 OutStreamer.EmitValue(Diff, Size); 1406 return; 1407 } 1408 1409 // Otherwise, emit with .set (aka assignment). 1410 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1411 OutStreamer.EmitAssignment(SetLabel, Diff); 1412 OutStreamer.EmitSymbolValue(SetLabel, Size); 1413} 1414 1415/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1416/// where the size in bytes of the directive is specified by Size and Hi/Lo 1417/// specify the labels. This implicitly uses .set if it is available. 1418void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1419 const MCSymbol *Lo, 1420 unsigned Size) const { 1421 1422 // Emit Hi+Offset - Lo 1423 // Get the Hi+Offset expression. 1424 const MCExpr *Plus = 1425 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1426 MCConstantExpr::Create(Offset, OutContext), 1427 OutContext); 1428 1429 // Get the Hi+Offset-Lo expression. 1430 const MCExpr *Diff = 1431 MCBinaryExpr::CreateSub(Plus, 1432 MCSymbolRefExpr::Create(Lo, OutContext), 1433 OutContext); 1434 1435 if (!MAI->hasSetDirective()) 1436 OutStreamer.EmitValue(Diff, Size); 1437 else { 1438 // Otherwise, emit with .set (aka assignment). 1439 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1440 OutStreamer.EmitAssignment(SetLabel, Diff); 1441 OutStreamer.EmitSymbolValue(SetLabel, Size); 1442 } 1443} 1444 1445/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1446/// where the size in bytes of the directive is specified by Size and Label 1447/// specifies the label. This implicitly uses .set if it is available. 1448void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1449 unsigned Size, 1450 bool IsSectionRelative) const { 1451 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) { 1452 OutStreamer.EmitCOFFSecRel32(Label); 1453 return; 1454 } 1455 1456 // Emit Label+Offset (or just Label if Offset is zero) 1457 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext); 1458 if (Offset) 1459 Expr = MCBinaryExpr::CreateAdd( 1460 Expr, MCConstantExpr::Create(Offset, OutContext), OutContext); 1461 1462 OutStreamer.EmitValue(Expr, Size); 1463} 1464 1465//===----------------------------------------------------------------------===// 1466 1467// EmitAlignment - Emit an alignment directive to the specified power of 1468// two boundary. For example, if you pass in 3 here, you will get an 8 1469// byte alignment. If a global value is specified, and if that global has 1470// an explicit alignment requested, it will override the alignment request 1471// if required for correctness. 1472// 1473void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1474 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits); 1475 1476 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1477 1478 if (getCurrentSection()->getKind().isText()) 1479 OutStreamer.EmitCodeAlignment(1 << NumBits); 1480 else 1481 OutStreamer.EmitValueToAlignment(1 << NumBits); 1482} 1483 1484//===----------------------------------------------------------------------===// 1485// Constant emission. 1486//===----------------------------------------------------------------------===// 1487 1488/// lowerConstant - Lower the specified LLVM Constant to an MCExpr. 1489/// 1490static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) { 1491 MCContext &Ctx = AP.OutContext; 1492 1493 if (CV->isNullValue() || isa<UndefValue>(CV)) 1494 return MCConstantExpr::Create(0, Ctx); 1495 1496 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1497 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1498 1499 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1500 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx); 1501 1502 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1503 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1504 1505 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1506 if (CE == 0) { 1507 llvm_unreachable("Unknown constant value to lower!"); 1508 } 1509 1510 if (const MCExpr *RelocExpr = 1511 AP.getObjFileLowering().getExecutableRelativeSymbol(CE, *AP.Mang, 1512 AP.TM)) 1513 return RelocExpr; 1514 1515 switch (CE->getOpcode()) { 1516 default: 1517 // If the code isn't optimized, there may be outstanding folding 1518 // opportunities. Attempt to fold the expression using DataLayout as a 1519 // last resort before giving up. 1520 if (Constant *C = 1521 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout())) 1522 if (C != CE) 1523 return lowerConstant(C, AP); 1524 1525 // Otherwise report the problem to the user. 1526 { 1527 std::string S; 1528 raw_string_ostream OS(S); 1529 OS << "Unsupported expression in static initializer: "; 1530 CE->printAsOperand(OS, /*PrintType=*/false, 1531 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1532 report_fatal_error(OS.str()); 1533 } 1534 case Instruction::GetElementPtr: { 1535 const DataLayout &DL = *AP.TM.getDataLayout(); 1536 // Generate a symbolic expression for the byte address 1537 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0); 1538 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI); 1539 1540 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP); 1541 if (!OffsetAI) 1542 return Base; 1543 1544 int64_t Offset = OffsetAI.getSExtValue(); 1545 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1546 Ctx); 1547 } 1548 1549 case Instruction::Trunc: 1550 // We emit the value and depend on the assembler to truncate the generated 1551 // expression properly. This is important for differences between 1552 // blockaddress labels. Since the two labels are in the same function, it 1553 // is reasonable to treat their delta as a 32-bit value. 1554 // FALL THROUGH. 1555 case Instruction::BitCast: 1556 return lowerConstant(CE->getOperand(0), AP); 1557 1558 case Instruction::IntToPtr: { 1559 const DataLayout &DL = *AP.TM.getDataLayout(); 1560 // Handle casts to pointers by changing them into casts to the appropriate 1561 // integer type. This promotes constant folding and simplifies this code. 1562 Constant *Op = CE->getOperand(0); 1563 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()), 1564 false/*ZExt*/); 1565 return lowerConstant(Op, AP); 1566 } 1567 1568 case Instruction::PtrToInt: { 1569 const DataLayout &DL = *AP.TM.getDataLayout(); 1570 // Support only foldable casts to/from pointers that can be eliminated by 1571 // changing the pointer to the appropriately sized integer type. 1572 Constant *Op = CE->getOperand(0); 1573 Type *Ty = CE->getType(); 1574 1575 const MCExpr *OpExpr = lowerConstant(Op, AP); 1576 1577 // We can emit the pointer value into this slot if the slot is an 1578 // integer slot equal to the size of the pointer. 1579 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType())) 1580 return OpExpr; 1581 1582 // Otherwise the pointer is smaller than the resultant integer, mask off 1583 // the high bits so we are sure to get a proper truncation if the input is 1584 // a constant expr. 1585 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType()); 1586 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1587 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1588 } 1589 1590 // The MC library also has a right-shift operator, but it isn't consistently 1591 // signed or unsigned between different targets. 1592 case Instruction::Add: 1593 case Instruction::Sub: 1594 case Instruction::Mul: 1595 case Instruction::SDiv: 1596 case Instruction::SRem: 1597 case Instruction::Shl: 1598 case Instruction::And: 1599 case Instruction::Or: 1600 case Instruction::Xor: { 1601 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP); 1602 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP); 1603 switch (CE->getOpcode()) { 1604 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1605 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1606 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1607 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1608 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1609 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1610 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1611 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1612 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1613 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1614 } 1615 } 1616 } 1617} 1618 1619static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP); 1620 1621/// isRepeatedByteSequence - Determine whether the given value is 1622/// composed of a repeated sequence of identical bytes and return the 1623/// byte value. If it is not a repeated sequence, return -1. 1624static int isRepeatedByteSequence(const ConstantDataSequential *V) { 1625 StringRef Data = V->getRawDataValues(); 1626 assert(!Data.empty() && "Empty aggregates should be CAZ node"); 1627 char C = Data[0]; 1628 for (unsigned i = 1, e = Data.size(); i != e; ++i) 1629 if (Data[i] != C) return -1; 1630 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1. 1631} 1632 1633 1634/// isRepeatedByteSequence - Determine whether the given value is 1635/// composed of a repeated sequence of identical bytes and return the 1636/// byte value. If it is not a repeated sequence, return -1. 1637static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) { 1638 1639 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { 1640 if (CI->getBitWidth() > 64) return -1; 1641 1642 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType()); 1643 uint64_t Value = CI->getZExtValue(); 1644 1645 // Make sure the constant is at least 8 bits long and has a power 1646 // of 2 bit width. This guarantees the constant bit width is 1647 // always a multiple of 8 bits, avoiding issues with padding out 1648 // to Size and other such corner cases. 1649 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1; 1650 1651 uint8_t Byte = static_cast<uint8_t>(Value); 1652 1653 for (unsigned i = 1; i < Size; ++i) { 1654 Value >>= 8; 1655 if (static_cast<uint8_t>(Value) != Byte) return -1; 1656 } 1657 return Byte; 1658 } 1659 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) { 1660 // Make sure all array elements are sequences of the same repeated 1661 // byte. 1662 assert(CA->getNumOperands() != 0 && "Should be a CAZ"); 1663 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM); 1664 if (Byte == -1) return -1; 1665 1666 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) { 1667 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM); 1668 if (ThisByte == -1) return -1; 1669 if (Byte != ThisByte) return -1; 1670 } 1671 return Byte; 1672 } 1673 1674 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V)) 1675 return isRepeatedByteSequence(CDS); 1676 1677 return -1; 1678} 1679 1680static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS, 1681 AsmPrinter &AP){ 1682 1683 // See if we can aggregate this into a .fill, if so, emit it as such. 1684 int Value = isRepeatedByteSequence(CDS, AP.TM); 1685 if (Value != -1) { 1686 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType()); 1687 // Don't emit a 1-byte object as a .fill. 1688 if (Bytes > 1) 1689 return AP.OutStreamer.EmitFill(Bytes, Value); 1690 } 1691 1692 // If this can be emitted with .ascii/.asciz, emit it as such. 1693 if (CDS->isString()) 1694 return AP.OutStreamer.EmitBytes(CDS->getAsString()); 1695 1696 // Otherwise, emit the values in successive locations. 1697 unsigned ElementByteSize = CDS->getElementByteSize(); 1698 if (isa<IntegerType>(CDS->getElementType())) { 1699 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1700 if (AP.isVerbose()) 1701 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1702 CDS->getElementAsInteger(i)); 1703 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i), 1704 ElementByteSize); 1705 } 1706 } else if (ElementByteSize == 4) { 1707 // FP Constants are printed as integer constants to avoid losing 1708 // precision. 1709 assert(CDS->getElementType()->isFloatTy()); 1710 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1711 union { 1712 float F; 1713 uint32_t I; 1714 }; 1715 1716 F = CDS->getElementAsFloat(i); 1717 if (AP.isVerbose()) 1718 AP.OutStreamer.GetCommentOS() << "float " << F << '\n'; 1719 AP.OutStreamer.EmitIntValue(I, 4); 1720 } 1721 } else { 1722 assert(CDS->getElementType()->isDoubleTy()); 1723 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1724 union { 1725 double F; 1726 uint64_t I; 1727 }; 1728 1729 F = CDS->getElementAsDouble(i); 1730 if (AP.isVerbose()) 1731 AP.OutStreamer.GetCommentOS() << "double " << F << '\n'; 1732 AP.OutStreamer.EmitIntValue(I, 8); 1733 } 1734 } 1735 1736 const DataLayout &DL = *AP.TM.getDataLayout(); 1737 unsigned Size = DL.getTypeAllocSize(CDS->getType()); 1738 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) * 1739 CDS->getNumElements(); 1740 if (unsigned Padding = Size - EmittedSize) 1741 AP.OutStreamer.EmitZeros(Padding); 1742 1743} 1744 1745static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) { 1746 // See if we can aggregate some values. Make sure it can be 1747 // represented as a series of bytes of the constant value. 1748 int Value = isRepeatedByteSequence(CA, AP.TM); 1749 1750 if (Value != -1) { 1751 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType()); 1752 AP.OutStreamer.EmitFill(Bytes, Value); 1753 } 1754 else { 1755 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1756 emitGlobalConstantImpl(CA->getOperand(i), AP); 1757 } 1758} 1759 1760static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) { 1761 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1762 emitGlobalConstantImpl(CV->getOperand(i), AP); 1763 1764 const DataLayout &DL = *AP.TM.getDataLayout(); 1765 unsigned Size = DL.getTypeAllocSize(CV->getType()); 1766 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) * 1767 CV->getType()->getNumElements(); 1768 if (unsigned Padding = Size - EmittedSize) 1769 AP.OutStreamer.EmitZeros(Padding); 1770} 1771 1772static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) { 1773 // Print the fields in successive locations. Pad to align if needed! 1774 const DataLayout *DL = AP.TM.getDataLayout(); 1775 unsigned Size = DL->getTypeAllocSize(CS->getType()); 1776 const StructLayout *Layout = DL->getStructLayout(CS->getType()); 1777 uint64_t SizeSoFar = 0; 1778 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1779 const Constant *Field = CS->getOperand(i); 1780 1781 // Check if padding is needed and insert one or more 0s. 1782 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType()); 1783 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1784 - Layout->getElementOffset(i)) - FieldSize; 1785 SizeSoFar += FieldSize + PadSize; 1786 1787 // Now print the actual field value. 1788 emitGlobalConstantImpl(Field, AP); 1789 1790 // Insert padding - this may include padding to increase the size of the 1791 // current field up to the ABI size (if the struct is not packed) as well 1792 // as padding to ensure that the next field starts at the right offset. 1793 AP.OutStreamer.EmitZeros(PadSize); 1794 } 1795 assert(SizeSoFar == Layout->getSizeInBytes() && 1796 "Layout of constant struct may be incorrect!"); 1797} 1798 1799static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) { 1800 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1801 1802 // First print a comment with what we think the original floating-point value 1803 // should have been. 1804 if (AP.isVerbose()) { 1805 SmallString<8> StrVal; 1806 CFP->getValueAPF().toString(StrVal); 1807 1808 CFP->getType()->print(AP.OutStreamer.GetCommentOS()); 1809 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n'; 1810 } 1811 1812 // Now iterate through the APInt chunks, emitting them in endian-correct 1813 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit 1814 // floats). 1815 unsigned NumBytes = API.getBitWidth() / 8; 1816 unsigned TrailingBytes = NumBytes % sizeof(uint64_t); 1817 const uint64_t *p = API.getRawData(); 1818 1819 // PPC's long double has odd notions of endianness compared to how LLVM 1820 // handles it: p[0] goes first for *big* endian on PPC. 1821 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) { 1822 int Chunk = API.getNumWords() - 1; 1823 1824 if (TrailingBytes) 1825 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes); 1826 1827 for (; Chunk >= 0; --Chunk) 1828 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t)); 1829 } else { 1830 unsigned Chunk; 1831 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk) 1832 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t)); 1833 1834 if (TrailingBytes) 1835 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes); 1836 } 1837 1838 // Emit the tail padding for the long double. 1839 const DataLayout &DL = *AP.TM.getDataLayout(); 1840 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) - 1841 DL.getTypeStoreSize(CFP->getType())); 1842} 1843 1844static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) { 1845 const DataLayout *DL = AP.TM.getDataLayout(); 1846 unsigned BitWidth = CI->getBitWidth(); 1847 1848 // Copy the value as we may massage the layout for constants whose bit width 1849 // is not a multiple of 64-bits. 1850 APInt Realigned(CI->getValue()); 1851 uint64_t ExtraBits = 0; 1852 unsigned ExtraBitsSize = BitWidth & 63; 1853 1854 if (ExtraBitsSize) { 1855 // The bit width of the data is not a multiple of 64-bits. 1856 // The extra bits are expected to be at the end of the chunk of the memory. 1857 // Little endian: 1858 // * Nothing to be done, just record the extra bits to emit. 1859 // Big endian: 1860 // * Record the extra bits to emit. 1861 // * Realign the raw data to emit the chunks of 64-bits. 1862 if (DL->isBigEndian()) { 1863 // Basically the structure of the raw data is a chunk of 64-bits cells: 1864 // 0 1 BitWidth / 64 1865 // [chunk1][chunk2] ... [chunkN]. 1866 // The most significant chunk is chunkN and it should be emitted first. 1867 // However, due to the alignment issue chunkN contains useless bits. 1868 // Realign the chunks so that they contain only useless information: 1869 // ExtraBits 0 1 (BitWidth / 64) - 1 1870 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN] 1871 ExtraBits = Realigned.getRawData()[0] & 1872 (((uint64_t)-1) >> (64 - ExtraBitsSize)); 1873 Realigned = Realigned.lshr(ExtraBitsSize); 1874 } else 1875 ExtraBits = Realigned.getRawData()[BitWidth / 64]; 1876 } 1877 1878 // We don't expect assemblers to support integer data directives 1879 // for more than 64 bits, so we emit the data in at most 64-bit 1880 // quantities at a time. 1881 const uint64_t *RawData = Realigned.getRawData(); 1882 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1883 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1884 AP.OutStreamer.EmitIntValue(Val, 8); 1885 } 1886 1887 if (ExtraBitsSize) { 1888 // Emit the extra bits after the 64-bits chunks. 1889 1890 // Emit a directive that fills the expected size. 1891 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType()); 1892 Size -= (BitWidth / 64) * 8; 1893 assert(Size && Size * 8 >= ExtraBitsSize && 1894 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) 1895 == ExtraBits && "Directive too small for extra bits."); 1896 AP.OutStreamer.EmitIntValue(ExtraBits, Size); 1897 } 1898} 1899 1900static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) { 1901 const DataLayout *DL = AP.TM.getDataLayout(); 1902 uint64_t Size = DL->getTypeAllocSize(CV->getType()); 1903 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) 1904 return AP.OutStreamer.EmitZeros(Size); 1905 1906 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1907 switch (Size) { 1908 case 1: 1909 case 2: 1910 case 4: 1911 case 8: 1912 if (AP.isVerbose()) 1913 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1914 CI->getZExtValue()); 1915 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size); 1916 return; 1917 default: 1918 emitGlobalConstantLargeInt(CI, AP); 1919 return; 1920 } 1921 } 1922 1923 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1924 return emitGlobalConstantFP(CFP, AP); 1925 1926 if (isa<ConstantPointerNull>(CV)) { 1927 AP.OutStreamer.EmitIntValue(0, Size); 1928 return; 1929 } 1930 1931 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV)) 1932 return emitGlobalConstantDataSequential(CDS, AP); 1933 1934 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1935 return emitGlobalConstantArray(CVA, AP); 1936 1937 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1938 return emitGlobalConstantStruct(CVS, AP); 1939 1940 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) { 1941 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of 1942 // vectors). 1943 if (CE->getOpcode() == Instruction::BitCast) 1944 return emitGlobalConstantImpl(CE->getOperand(0), AP); 1945 1946 if (Size > 8) { 1947 // If the constant expression's size is greater than 64-bits, then we have 1948 // to emit the value in chunks. Try to constant fold the value and emit it 1949 // that way. 1950 Constant *New = ConstantFoldConstantExpression(CE, DL); 1951 if (New && New != CE) 1952 return emitGlobalConstantImpl(New, AP); 1953 } 1954 } 1955 1956 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1957 return emitGlobalConstantVector(V, AP); 1958 1959 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1960 // thread the streamer with EmitValue. 1961 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size); 1962} 1963 1964/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1965void AsmPrinter::EmitGlobalConstant(const Constant *CV) { 1966 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType()); 1967 if (Size) 1968 emitGlobalConstantImpl(CV, *this); 1969 else if (MAI->hasSubsectionsViaSymbols()) { 1970 // If the global has zero size, emit a single byte so that two labels don't 1971 // look like they are at the same location. 1972 OutStreamer.EmitIntValue(0, 1); 1973 } 1974} 1975 1976void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1977 // Target doesn't support this yet! 1978 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1979} 1980 1981void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1982 if (Offset > 0) 1983 OS << '+' << Offset; 1984 else if (Offset < 0) 1985 OS << Offset; 1986} 1987 1988//===----------------------------------------------------------------------===// 1989// Symbol Lowering Routines. 1990//===----------------------------------------------------------------------===// 1991 1992/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1993/// temporary label with the specified stem and unique ID. 1994MCSymbol *AsmPrinter::GetTempSymbol(Twine Name, unsigned ID) const { 1995 const DataLayout *DL = TM.getDataLayout(); 1996 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix()) + 1997 Name + Twine(ID)); 1998} 1999 2000/// GetTempSymbol - Return an assembler temporary label with the specified 2001/// stem. 2002MCSymbol *AsmPrinter::GetTempSymbol(Twine Name) const { 2003 const DataLayout *DL = TM.getDataLayout(); 2004 return OutContext.GetOrCreateSymbol(Twine(DL->getPrivateGlobalPrefix())+ 2005 Name); 2006} 2007 2008 2009MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 2010 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 2011} 2012 2013MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 2014 return MMI->getAddrLabelSymbol(BB); 2015} 2016 2017/// GetCPISymbol - Return the symbol for the specified constant pool entry. 2018MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 2019 const DataLayout *DL = TM.getDataLayout(); 2020 return OutContext.GetOrCreateSymbol 2021 (Twine(DL->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 2022 + "_" + Twine(CPID)); 2023} 2024 2025/// GetJTISymbol - Return the symbol for the specified jump table entry. 2026MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 2027 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 2028} 2029 2030/// GetJTSetSymbol - Return the symbol for the specified jump table .set 2031/// FIXME: privatize to AsmPrinter. 2032MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 2033 const DataLayout *DL = TM.getDataLayout(); 2034 return OutContext.GetOrCreateSymbol 2035 (Twine(DL->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 2036 Twine(UID) + "_set_" + Twine(MBBID)); 2037} 2038 2039MCSymbol *AsmPrinter::getSymbolWithGlobalValueBase(const GlobalValue *GV, 2040 StringRef Suffix) const { 2041 return getObjFileLowering().getSymbolWithGlobalValueBase(GV, Suffix, *Mang, 2042 TM); 2043} 2044 2045/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 2046/// ExternalSymbol. 2047MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 2048 SmallString<60> NameStr; 2049 Mang->getNameWithPrefix(NameStr, Sym); 2050 return OutContext.GetOrCreateSymbol(NameStr.str()); 2051} 2052 2053 2054 2055/// PrintParentLoopComment - Print comments about parent loops of this one. 2056static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2057 unsigned FunctionNumber) { 2058 if (Loop == 0) return; 2059 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 2060 OS.indent(Loop->getLoopDepth()*2) 2061 << "Parent Loop BB" << FunctionNumber << "_" 2062 << Loop->getHeader()->getNumber() 2063 << " Depth=" << Loop->getLoopDepth() << '\n'; 2064} 2065 2066 2067/// PrintChildLoopComment - Print comments about child loops within 2068/// the loop for this basic block, with nesting. 2069static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2070 unsigned FunctionNumber) { 2071 // Add child loop information 2072 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 2073 OS.indent((*CL)->getLoopDepth()*2) 2074 << "Child Loop BB" << FunctionNumber << "_" 2075 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 2076 << '\n'; 2077 PrintChildLoopComment(OS, *CL, FunctionNumber); 2078 } 2079} 2080 2081/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks. 2082static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB, 2083 const MachineLoopInfo *LI, 2084 const AsmPrinter &AP) { 2085 // Add loop depth information 2086 const MachineLoop *Loop = LI->getLoopFor(&MBB); 2087 if (Loop == 0) return; 2088 2089 MachineBasicBlock *Header = Loop->getHeader(); 2090 assert(Header && "No header for loop"); 2091 2092 // If this block is not a loop header, just print out what is the loop header 2093 // and return. 2094 if (Header != &MBB) { 2095 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 2096 Twine(AP.getFunctionNumber())+"_" + 2097 Twine(Loop->getHeader()->getNumber())+ 2098 " Depth="+Twine(Loop->getLoopDepth())); 2099 return; 2100 } 2101 2102 // Otherwise, it is a loop header. Print out information about child and 2103 // parent loops. 2104 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 2105 2106 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 2107 2108 OS << "=>"; 2109 OS.indent(Loop->getLoopDepth()*2-2); 2110 2111 OS << "This "; 2112 if (Loop->empty()) 2113 OS << "Inner "; 2114 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 2115 2116 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 2117} 2118 2119 2120/// EmitBasicBlockStart - This method prints the label for the specified 2121/// MachineBasicBlock, an alignment (if present) and a comment describing 2122/// it if appropriate. 2123void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 2124 // Emit an alignment directive for this block, if needed. 2125 if (unsigned Align = MBB->getAlignment()) 2126 EmitAlignment(Align); 2127 2128 // If the block has its address taken, emit any labels that were used to 2129 // reference the block. It is possible that there is more than one label 2130 // here, because multiple LLVM BB's may have been RAUW'd to this block after 2131 // the references were generated. 2132 if (MBB->hasAddressTaken()) { 2133 const BasicBlock *BB = MBB->getBasicBlock(); 2134 if (isVerbose()) 2135 OutStreamer.AddComment("Block address taken"); 2136 2137 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 2138 2139 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 2140 OutStreamer.EmitLabel(Syms[i]); 2141 } 2142 2143 // Print some verbose block comments. 2144 if (isVerbose()) { 2145 if (const BasicBlock *BB = MBB->getBasicBlock()) 2146 if (BB->hasName()) 2147 OutStreamer.AddComment("%" + BB->getName()); 2148 emitBasicBlockLoopComments(*MBB, LI, *this); 2149 } 2150 2151 // Print the main label for the block. 2152 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 2153 if (isVerbose()) { 2154 // NOTE: Want this comment at start of line, don't emit with AddComment. 2155 OutStreamer.emitRawComment(" BB#" + Twine(MBB->getNumber()) + ":", false); 2156 } 2157 } else { 2158 OutStreamer.EmitLabel(MBB->getSymbol()); 2159 } 2160} 2161 2162void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 2163 bool IsDefinition) const { 2164 MCSymbolAttr Attr = MCSA_Invalid; 2165 2166 switch (Visibility) { 2167 default: break; 2168 case GlobalValue::HiddenVisibility: 2169 if (IsDefinition) 2170 Attr = MAI->getHiddenVisibilityAttr(); 2171 else 2172 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 2173 break; 2174 case GlobalValue::ProtectedVisibility: 2175 Attr = MAI->getProtectedVisibilityAttr(); 2176 break; 2177 } 2178 2179 if (Attr != MCSA_Invalid) 2180 OutStreamer.EmitSymbolAttribute(Sym, Attr); 2181} 2182 2183/// isBlockOnlyReachableByFallthough - Return true if the basic block has 2184/// exactly one predecessor and the control transfer mechanism between 2185/// the predecessor and this block is a fall-through. 2186bool AsmPrinter:: 2187isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 2188 // If this is a landing pad, it isn't a fall through. If it has no preds, 2189 // then nothing falls through to it. 2190 if (MBB->isLandingPad() || MBB->pred_empty()) 2191 return false; 2192 2193 // If there isn't exactly one predecessor, it can't be a fall through. 2194 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 2195 ++PI2; 2196 if (PI2 != MBB->pred_end()) 2197 return false; 2198 2199 // The predecessor has to be immediately before this block. 2200 MachineBasicBlock *Pred = *PI; 2201 2202 if (!Pred->isLayoutSuccessor(MBB)) 2203 return false; 2204 2205 // If the block is completely empty, then it definitely does fall through. 2206 if (Pred->empty()) 2207 return true; 2208 2209 // Check the terminators in the previous blocks 2210 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(), 2211 IE = Pred->end(); II != IE; ++II) { 2212 MachineInstr &MI = *II; 2213 2214 // If it is not a simple branch, we are in a table somewhere. 2215 if (!MI.isBranch() || MI.isIndirectBranch()) 2216 return false; 2217 2218 // If we are the operands of one of the branches, this is not a fall 2219 // through. Note that targets with delay slots will usually bundle 2220 // terminators with the delay slot instruction. 2221 for (ConstMIBundleOperands OP(&MI); OP.isValid(); ++OP) { 2222 if (OP->isJTI()) 2223 return false; 2224 if (OP->isMBB() && OP->getMBB() == MBB) 2225 return false; 2226 } 2227 } 2228 2229 return true; 2230} 2231 2232 2233 2234GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 2235 if (!S->usesMetadata()) 2236 return 0; 2237 2238 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 2239 gcp_map_type::iterator GCPI = GCMap.find(S); 2240 if (GCPI != GCMap.end()) 2241 return GCPI->second; 2242 2243 const char *Name = S->getName().c_str(); 2244 2245 for (GCMetadataPrinterRegistry::iterator 2246 I = GCMetadataPrinterRegistry::begin(), 2247 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 2248 if (strcmp(Name, I->getName()) == 0) { 2249 GCMetadataPrinter *GMP = I->instantiate(); 2250 GMP->S = S; 2251 GCMap.insert(std::make_pair(S, GMP)); 2252 return GMP; 2253 } 2254 2255 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 2256} 2257 2258/// Pin vtable to this file. 2259AsmPrinterHandler::~AsmPrinterHandler() {} 2260