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 "llvm/DebugInfo.h" 19#include "llvm/Module.h" 20#include "llvm/CodeGen/GCMetadataPrinter.h" 21#include "llvm/CodeGen/MachineConstantPool.h" 22#include "llvm/CodeGen/MachineFrameInfo.h" 23#include "llvm/CodeGen/MachineFunction.h" 24#include "llvm/CodeGen/MachineJumpTableInfo.h" 25#include "llvm/CodeGen/MachineLoopInfo.h" 26#include "llvm/CodeGen/MachineModuleInfo.h" 27#include "llvm/Analysis/ConstantFolding.h" 28#include "llvm/MC/MCAsmInfo.h" 29#include "llvm/MC/MCContext.h" 30#include "llvm/MC/MCExpr.h" 31#include "llvm/MC/MCInst.h" 32#include "llvm/MC/MCSection.h" 33#include "llvm/MC/MCStreamer.h" 34#include "llvm/MC/MCSymbol.h" 35#include "llvm/Target/Mangler.h" 36#include "llvm/Target/TargetData.h" 37#include "llvm/Target/TargetInstrInfo.h" 38#include "llvm/Target/TargetLowering.h" 39#include "llvm/Target/TargetLoweringObjectFile.h" 40#include "llvm/Target/TargetOptions.h" 41#include "llvm/Target/TargetRegisterInfo.h" 42#include "llvm/Assembly/Writer.h" 43#include "llvm/ADT/SmallString.h" 44#include "llvm/ADT/Statistic.h" 45#include "llvm/Support/ErrorHandling.h" 46#include "llvm/Support/Format.h" 47#include "llvm/Support/MathExtras.h" 48#include "llvm/Support/Timer.h" 49using namespace llvm; 50 51static const char *DWARFGroupName = "DWARF Emission"; 52static const char *DbgTimerName = "DWARF Debug Writer"; 53static const char *EHTimerName = "DWARF Exception Writer"; 54 55STATISTIC(EmittedInsts, "Number of machine instrs printed"); 56 57char AsmPrinter::ID = 0; 58 59typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 60static gcp_map_type &getGCMap(void *&P) { 61 if (P == 0) 62 P = new gcp_map_type(); 63 return *(gcp_map_type*)P; 64} 65 66 67/// getGVAlignmentLog2 - Return the alignment to use for the specified global 68/// value in log2 form. This rounds up to the preferred alignment if possible 69/// and legal. 70static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 71 unsigned InBits = 0) { 72 unsigned NumBits = 0; 73 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 74 NumBits = TD.getPreferredAlignmentLog(GVar); 75 76 // If InBits is specified, round it to it. 77 if (InBits > NumBits) 78 NumBits = InBits; 79 80 // If the GV has a specified alignment, take it into account. 81 if (GV->getAlignment() == 0) 82 return NumBits; 83 84 unsigned GVAlign = Log2_32(GV->getAlignment()); 85 86 // If the GVAlign is larger than NumBits, or if we are required to obey 87 // NumBits because the GV has an assigned section, obey it. 88 if (GVAlign > NumBits || GV->hasSection()) 89 NumBits = GVAlign; 90 return NumBits; 91} 92 93 94 95 96AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 97 : MachineFunctionPass(ID), 98 TM(tm), MAI(tm.getMCAsmInfo()), 99 OutContext(Streamer.getContext()), 100 OutStreamer(Streamer), 101 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 102 DD = 0; DE = 0; MMI = 0; LI = 0; 103 CurrentFnSym = CurrentFnSymForSize = 0; 104 GCMetadataPrinters = 0; 105 VerboseAsm = Streamer.isVerboseAsm(); 106} 107 108AsmPrinter::~AsmPrinter() { 109 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 110 111 if (GCMetadataPrinters != 0) { 112 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 113 114 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 115 delete I->second; 116 delete &GCMap; 117 GCMetadataPrinters = 0; 118 } 119 120 delete &OutStreamer; 121} 122 123/// getFunctionNumber - Return a unique ID for the current function. 124/// 125unsigned AsmPrinter::getFunctionNumber() const { 126 return MF->getFunctionNumber(); 127} 128 129const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 130 return TM.getTargetLowering()->getObjFileLowering(); 131} 132 133 134/// getTargetData - Return information about data layout. 135const TargetData &AsmPrinter::getTargetData() const { 136 return *TM.getTargetData(); 137} 138 139/// getCurrentSection() - Return the current section we are emitting to. 140const MCSection *AsmPrinter::getCurrentSection() const { 141 return OutStreamer.getCurrentSection(); 142} 143 144 145 146void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 147 AU.setPreservesAll(); 148 MachineFunctionPass::getAnalysisUsage(AU); 149 AU.addRequired<MachineModuleInfo>(); 150 AU.addRequired<GCModuleInfo>(); 151 if (isVerbose()) 152 AU.addRequired<MachineLoopInfo>(); 153} 154 155bool AsmPrinter::doInitialization(Module &M) { 156 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 157 MMI->AnalyzeModule(M); 158 159 // Initialize TargetLoweringObjectFile. 160 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 161 .Initialize(OutContext, TM); 162 163 Mang = new Mangler(OutContext, *TM.getTargetData()); 164 165 // Allow the target to emit any magic that it wants at the start of the file. 166 EmitStartOfAsmFile(M); 167 168 // Very minimal debug info. It is ignored if we emit actual debug info. If we 169 // don't, this at least helps the user find where a global came from. 170 if (MAI->hasSingleParameterDotFile()) { 171 // .file "foo.c" 172 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 173 } 174 175 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 176 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 177 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 178 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 179 MP->beginAssembly(*this); 180 181 // Emit module-level inline asm if it exists. 182 if (!M.getModuleInlineAsm().empty()) { 183 OutStreamer.AddComment("Start of file scope inline assembly"); 184 OutStreamer.AddBlankLine(); 185 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 186 OutStreamer.AddComment("End of file scope inline assembly"); 187 OutStreamer.AddBlankLine(); 188 } 189 190 if (MAI->doesSupportDebugInformation()) 191 DD = new DwarfDebug(this, &M); 192 193 switch (MAI->getExceptionHandlingType()) { 194 case ExceptionHandling::None: 195 return false; 196 case ExceptionHandling::SjLj: 197 case ExceptionHandling::DwarfCFI: 198 DE = new DwarfCFIException(this); 199 return false; 200 case ExceptionHandling::ARM: 201 DE = new ARMException(this); 202 return false; 203 case ExceptionHandling::Win64: 204 DE = new Win64Exception(this); 205 return false; 206 } 207 208 llvm_unreachable("Unknown exception type."); 209} 210 211void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 212 switch ((GlobalValue::LinkageTypes)Linkage) { 213 case GlobalValue::CommonLinkage: 214 case GlobalValue::LinkOnceAnyLinkage: 215 case GlobalValue::LinkOnceODRLinkage: 216 case GlobalValue::LinkOnceODRAutoHideLinkage: 217 case GlobalValue::WeakAnyLinkage: 218 case GlobalValue::WeakODRLinkage: 219 case GlobalValue::LinkerPrivateWeakLinkage: 220 if (MAI->getWeakDefDirective() != 0) { 221 // .globl _foo 222 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 223 224 if ((GlobalValue::LinkageTypes)Linkage != 225 GlobalValue::LinkOnceODRAutoHideLinkage) 226 // .weak_definition _foo 227 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 228 else 229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 230 } else if (MAI->getLinkOnceDirective() != 0) { 231 // .globl _foo 232 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 233 //NOTE: linkonce is handled by the section the symbol was assigned to. 234 } else { 235 // .weak _foo 236 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 237 } 238 break; 239 case GlobalValue::DLLExportLinkage: 240 case GlobalValue::AppendingLinkage: 241 // FIXME: appending linkage variables should go into a section of 242 // their name or something. For now, just emit them as external. 243 case GlobalValue::ExternalLinkage: 244 // If external or appending, declare as a global symbol. 245 // .globl _foo 246 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 247 break; 248 case GlobalValue::PrivateLinkage: 249 case GlobalValue::InternalLinkage: 250 case GlobalValue::LinkerPrivateLinkage: 251 break; 252 default: 253 llvm_unreachable("Unknown linkage type!"); 254 } 255} 256 257 258/// EmitGlobalVariable - Emit the specified global variable to the .s file. 259void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 260 if (GV->hasInitializer()) { 261 // Check to see if this is a special global used by LLVM, if so, emit it. 262 if (EmitSpecialLLVMGlobal(GV)) 263 return; 264 265 if (isVerbose()) { 266 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 267 /*PrintType=*/false, GV->getParent()); 268 OutStreamer.GetCommentOS() << '\n'; 269 } 270 } 271 272 MCSymbol *GVSym = Mang->getSymbol(GV); 273 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration()); 274 275 if (!GV->hasInitializer()) // External globals require no extra code. 276 return; 277 278 if (MAI->hasDotTypeDotSizeDirective()) 279 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 280 281 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 282 283 const TargetData *TD = TM.getTargetData(); 284 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 285 286 // If the alignment is specified, we *must* obey it. Overaligning a global 287 // with a specified alignment is a prompt way to break globals emitted to 288 // sections and expected to be contiguous (e.g. ObjC metadata). 289 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 290 291 // Handle common and BSS local symbols (.lcomm). 292 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 293 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 294 unsigned Align = 1 << AlignLog; 295 296 // Handle common symbols. 297 if (GVKind.isCommon()) { 298 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 299 Align = 0; 300 301 // .comm _foo, 42, 4 302 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 303 return; 304 } 305 306 // Handle local BSS symbols. 307 if (MAI->hasMachoZeroFillDirective()) { 308 const MCSection *TheSection = 309 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 310 // .zerofill __DATA, __bss, _foo, 400, 5 311 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align); 312 return; 313 } 314 315 if (Align == 1 || 316 MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) { 317 // .lcomm _foo, 42 318 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align); 319 return; 320 } 321 322 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 323 Align = 0; 324 325 // .local _foo 326 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 327 // .comm _foo, 42, 4 328 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 329 return; 330 } 331 332 const MCSection *TheSection = 333 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 334 335 // Handle the zerofill directive on darwin, which is a special form of BSS 336 // emission. 337 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 338 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 339 340 // .globl _foo 341 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 342 // .zerofill __DATA, __common, _foo, 400, 5 343 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 344 return; 345 } 346 347 // Handle thread local data for mach-o which requires us to output an 348 // additional structure of data and mangle the original symbol so that we 349 // can reference it later. 350 // 351 // TODO: This should become an "emit thread local global" method on TLOF. 352 // All of this macho specific stuff should be sunk down into TLOFMachO and 353 // stuff like "TLSExtraDataSection" should no longer be part of the parent 354 // TLOF class. This will also make it more obvious that stuff like 355 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 356 // specific code. 357 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 358 // Emit the .tbss symbol 359 MCSymbol *MangSym = 360 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 361 362 if (GVKind.isThreadBSS()) 363 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 364 else if (GVKind.isThreadData()) { 365 OutStreamer.SwitchSection(TheSection); 366 367 EmitAlignment(AlignLog, GV); 368 OutStreamer.EmitLabel(MangSym); 369 370 EmitGlobalConstant(GV->getInitializer()); 371 } 372 373 OutStreamer.AddBlankLine(); 374 375 // Emit the variable struct for the runtime. 376 const MCSection *TLVSect 377 = getObjFileLowering().getTLSExtraDataSection(); 378 379 OutStreamer.SwitchSection(TLVSect); 380 // Emit the linkage here. 381 EmitLinkage(GV->getLinkage(), GVSym); 382 OutStreamer.EmitLabel(GVSym); 383 384 // Three pointers in size: 385 // - __tlv_bootstrap - used to make sure support exists 386 // - spare pointer, used when mapped by the runtime 387 // - pointer to mangled symbol above with initializer 388 unsigned PtrSize = TD->getPointerSizeInBits()/8; 389 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 390 PtrSize, 0); 391 OutStreamer.EmitIntValue(0, PtrSize, 0); 392 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 393 394 OutStreamer.AddBlankLine(); 395 return; 396 } 397 398 OutStreamer.SwitchSection(TheSection); 399 400 EmitLinkage(GV->getLinkage(), GVSym); 401 EmitAlignment(AlignLog, GV); 402 403 OutStreamer.EmitLabel(GVSym); 404 405 EmitGlobalConstant(GV->getInitializer()); 406 407 if (MAI->hasDotTypeDotSizeDirective()) 408 // .size foo, 42 409 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 410 411 OutStreamer.AddBlankLine(); 412} 413 414/// EmitFunctionHeader - This method emits the header for the current 415/// function. 416void AsmPrinter::EmitFunctionHeader() { 417 // Print out constants referenced by the function 418 EmitConstantPool(); 419 420 // Print the 'header' of function. 421 const Function *F = MF->getFunction(); 422 423 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 424 EmitVisibility(CurrentFnSym, F->getVisibility()); 425 426 EmitLinkage(F->getLinkage(), CurrentFnSym); 427 EmitAlignment(MF->getAlignment(), F); 428 429 if (MAI->hasDotTypeDotSizeDirective()) 430 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 431 432 if (isVerbose()) { 433 WriteAsOperand(OutStreamer.GetCommentOS(), F, 434 /*PrintType=*/false, F->getParent()); 435 OutStreamer.GetCommentOS() << '\n'; 436 } 437 438 // Emit the CurrentFnSym. This is a virtual function to allow targets to 439 // do their wild and crazy things as required. 440 EmitFunctionEntryLabel(); 441 442 // If the function had address-taken blocks that got deleted, then we have 443 // references to the dangling symbols. Emit them at the start of the function 444 // so that we don't get references to undefined symbols. 445 std::vector<MCSymbol*> DeadBlockSyms; 446 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 447 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 448 OutStreamer.AddComment("Address taken block that was later removed"); 449 OutStreamer.EmitLabel(DeadBlockSyms[i]); 450 } 451 452 // Add some workaround for linkonce linkage on Cygwin\MinGW. 453 if (MAI->getLinkOnceDirective() != 0 && 454 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 455 // FIXME: What is this? 456 MCSymbol *FakeStub = 457 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 458 CurrentFnSym->getName()); 459 OutStreamer.EmitLabel(FakeStub); 460 } 461 462 // Emit pre-function debug and/or EH information. 463 if (DE) { 464 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 465 DE->BeginFunction(MF); 466 } 467 if (DD) { 468 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 469 DD->beginFunction(MF); 470 } 471} 472 473/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 474/// function. This can be overridden by targets as required to do custom stuff. 475void AsmPrinter::EmitFunctionEntryLabel() { 476 // The function label could have already been emitted if two symbols end up 477 // conflicting due to asm renaming. Detect this and emit an error. 478 if (CurrentFnSym->isUndefined()) 479 return OutStreamer.EmitLabel(CurrentFnSym); 480 481 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 482 "' label emitted multiple times to assembly file"); 483} 484 485/// emitComments - Pretty-print comments for instructions. 486static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 487 const MachineFunction *MF = MI.getParent()->getParent(); 488 const TargetMachine &TM = MF->getTarget(); 489 490 // Check for spills and reloads 491 int FI; 492 493 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 494 495 // We assume a single instruction only has a spill or reload, not 496 // both. 497 const MachineMemOperand *MMO; 498 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 499 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 500 MMO = *MI.memoperands_begin(); 501 CommentOS << MMO->getSize() << "-byte Reload\n"; 502 } 503 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 504 if (FrameInfo->isSpillSlotObjectIndex(FI)) 505 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 506 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 507 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 508 MMO = *MI.memoperands_begin(); 509 CommentOS << MMO->getSize() << "-byte Spill\n"; 510 } 511 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 512 if (FrameInfo->isSpillSlotObjectIndex(FI)) 513 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 514 } 515 516 // Check for spill-induced copies 517 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 518 CommentOS << " Reload Reuse\n"; 519} 520 521/// emitImplicitDef - This method emits the specified machine instruction 522/// that is an implicit def. 523static void emitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 524 unsigned RegNo = MI->getOperand(0).getReg(); 525 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 526 AP.TM.getRegisterInfo()->getName(RegNo)); 527 AP.OutStreamer.AddBlankLine(); 528} 529 530static void emitKill(const MachineInstr *MI, AsmPrinter &AP) { 531 std::string Str = "kill:"; 532 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 533 const MachineOperand &Op = MI->getOperand(i); 534 assert(Op.isReg() && "KILL instruction must have only register operands"); 535 Str += ' '; 536 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 537 Str += (Op.isDef() ? "<def>" : "<kill>"); 538 } 539 AP.OutStreamer.AddComment(Str); 540 AP.OutStreamer.AddBlankLine(); 541} 542 543/// emitDebugValueComment - This method handles the target-independent form 544/// of DBG_VALUE, returning true if it was able to do so. A false return 545/// means the target will need to handle MI in EmitInstruction. 546static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 547 // This code handles only the 3-operand target-independent form. 548 if (MI->getNumOperands() != 3) 549 return false; 550 551 SmallString<128> Str; 552 raw_svector_ostream OS(Str); 553 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 554 555 // cast away const; DIetc do not take const operands for some reason. 556 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 557 if (V.getContext().isSubprogram()) 558 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 559 OS << V.getName() << " <- "; 560 561 // Register or immediate value. Register 0 means undef. 562 if (MI->getOperand(0).isFPImm()) { 563 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 564 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 565 OS << (double)APF.convertToFloat(); 566 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 567 OS << APF.convertToDouble(); 568 } else { 569 // There is no good way to print long double. Convert a copy to 570 // double. Ah well, it's only a comment. 571 bool ignored; 572 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 573 &ignored); 574 OS << "(long double) " << APF.convertToDouble(); 575 } 576 } else if (MI->getOperand(0).isImm()) { 577 OS << MI->getOperand(0).getImm(); 578 } else if (MI->getOperand(0).isCImm()) { 579 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/); 580 } else { 581 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 582 if (MI->getOperand(0).getReg() == 0) { 583 // Suppress offset, it is not meaningful here. 584 OS << "undef"; 585 // NOTE: Want this comment at start of line, don't emit with AddComment. 586 AP.OutStreamer.EmitRawText(OS.str()); 587 return true; 588 } 589 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 590 } 591 592 OS << '+' << MI->getOperand(1).getImm(); 593 // NOTE: Want this comment at start of line, don't emit with AddComment. 594 AP.OutStreamer.EmitRawText(OS.str()); 595 return true; 596} 597 598AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() { 599 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI && 600 MF->getFunction()->needsUnwindTableEntry()) 601 return CFI_M_EH; 602 603 if (MMI->hasDebugInfo()) 604 return CFI_M_Debug; 605 606 return CFI_M_None; 607} 608 609bool AsmPrinter::needsSEHMoves() { 610 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 && 611 MF->getFunction()->needsUnwindTableEntry(); 612} 613 614bool AsmPrinter::needsRelocationsForDwarfStringPool() const { 615 return MAI->doesDwarfUseRelocationsAcrossSections(); 616} 617 618void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 619 MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 620 621 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) 622 return; 623 624 if (needsCFIMoves() == CFI_M_None) 625 return; 626 627 if (MMI->getCompactUnwindEncoding() != 0) 628 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding()); 629 630 MachineModuleInfo &MMI = MF->getMMI(); 631 std::vector<MachineMove> &Moves = MMI.getFrameMoves(); 632 bool FoundOne = false; 633 (void)FoundOne; 634 for (std::vector<MachineMove>::iterator I = Moves.begin(), 635 E = Moves.end(); I != E; ++I) { 636 if (I->getLabel() == Label) { 637 EmitCFIFrameMove(*I); 638 FoundOne = true; 639 } 640 } 641 assert(FoundOne); 642} 643 644/// EmitFunctionBody - This method emits the body and trailer for a 645/// function. 646void AsmPrinter::EmitFunctionBody() { 647 // Emit target-specific gunk before the function body. 648 EmitFunctionBodyStart(); 649 650 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 651 652 // Print out code for the function. 653 bool HasAnyRealCode = false; 654 const MachineInstr *LastMI = 0; 655 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 656 I != E; ++I) { 657 // Print a label for the basic block. 658 EmitBasicBlockStart(I); 659 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 660 II != IE; ++II) { 661 LastMI = II; 662 663 // Print the assembly for the instruction. 664 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 665 !II->isDebugValue()) { 666 HasAnyRealCode = true; 667 ++EmittedInsts; 668 } 669 670 if (ShouldPrintDebugScopes) { 671 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 672 DD->beginInstruction(II); 673 } 674 675 if (isVerbose()) 676 emitComments(*II, OutStreamer.GetCommentOS()); 677 678 switch (II->getOpcode()) { 679 case TargetOpcode::PROLOG_LABEL: 680 emitPrologLabel(*II); 681 break; 682 683 case TargetOpcode::EH_LABEL: 684 case TargetOpcode::GC_LABEL: 685 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 686 break; 687 case TargetOpcode::INLINEASM: 688 EmitInlineAsm(II); 689 break; 690 case TargetOpcode::DBG_VALUE: 691 if (isVerbose()) { 692 if (!emitDebugValueComment(II, *this)) 693 EmitInstruction(II); 694 } 695 break; 696 case TargetOpcode::IMPLICIT_DEF: 697 if (isVerbose()) emitImplicitDef(II, *this); 698 break; 699 case TargetOpcode::KILL: 700 if (isVerbose()) emitKill(II, *this); 701 break; 702 default: 703 if (!TM.hasMCUseLoc()) 704 MCLineEntry::Make(&OutStreamer, getCurrentSection()); 705 706 EmitInstruction(II); 707 break; 708 } 709 710 if (ShouldPrintDebugScopes) { 711 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 712 DD->endInstruction(II); 713 } 714 } 715 } 716 717 // If the last instruction was a prolog label, then we have a situation where 718 // we emitted a prolog but no function body. This results in the ending prolog 719 // label equaling the end of function label and an invalid "row" in the 720 // FDE. We need to emit a noop in this situation so that the FDE's rows are 721 // valid. 722 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 723 724 // If the function is empty and the object file uses .subsections_via_symbols, 725 // then we need to emit *something* to the function body to prevent the 726 // labels from collapsing together. Just emit a noop. 727 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 728 MCInst Noop; 729 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 730 if (Noop.getOpcode()) { 731 OutStreamer.AddComment("avoids zero-length function"); 732 OutStreamer.EmitInstruction(Noop); 733 } else // Target not mc-ized yet. 734 OutStreamer.EmitRawText(StringRef("\tnop\n")); 735 } 736 737 const Function *F = MF->getFunction(); 738 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) { 739 const BasicBlock *BB = i; 740 if (!BB->hasAddressTaken()) 741 continue; 742 MCSymbol *Sym = GetBlockAddressSymbol(BB); 743 if (Sym->isDefined()) 744 continue; 745 OutStreamer.AddComment("Address of block that was removed by CodeGen"); 746 OutStreamer.EmitLabel(Sym); 747 } 748 749 // Emit target-specific gunk after the function body. 750 EmitFunctionBodyEnd(); 751 752 // If the target wants a .size directive for the size of the function, emit 753 // it. 754 if (MAI->hasDotTypeDotSizeDirective()) { 755 // Create a symbol for the end of function, so we can get the size as 756 // difference between the function label and the temp label. 757 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 758 OutStreamer.EmitLabel(FnEndLabel); 759 760 const MCExpr *SizeExp = 761 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 762 MCSymbolRefExpr::Create(CurrentFnSymForSize, 763 OutContext), 764 OutContext); 765 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 766 } 767 768 // Emit post-function debug information. 769 if (DD) { 770 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 771 DD->endFunction(MF); 772 } 773 if (DE) { 774 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 775 DE->EndFunction(); 776 } 777 MMI->EndFunction(); 778 779 // Print out jump tables referenced by the function. 780 EmitJumpTableInfo(); 781 782 OutStreamer.AddBlankLine(); 783} 784 785/// getDebugValueLocation - Get location information encoded by DBG_VALUE 786/// operands. 787MachineLocation AsmPrinter:: 788getDebugValueLocation(const MachineInstr *MI) const { 789 // Target specific DBG_VALUE instructions are handled by each target. 790 return MachineLocation(); 791} 792 793/// EmitDwarfRegOp - Emit dwarf register operation. 794void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const { 795 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 796 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false); 797 798 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0; 799 ++SR) { 800 Reg = TRI->getDwarfRegNum(*SR, false); 801 // FIXME: Get the bit range this register uses of the superregister 802 // so that we can produce a DW_OP_bit_piece 803 } 804 805 // FIXME: Handle cases like a super register being encoded as 806 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33 807 808 // FIXME: We have no reasonable way of handling errors in here. The 809 // caller might be in the middle of an dwarf expression. We should 810 // probably assert that Reg >= 0 once debug info generation is more mature. 811 812 if (int Offset = MLoc.getOffset()) { 813 if (Reg < 32) { 814 OutStreamer.AddComment( 815 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg)); 816 EmitInt8(dwarf::DW_OP_breg0 + Reg); 817 } else { 818 OutStreamer.AddComment("DW_OP_bregx"); 819 EmitInt8(dwarf::DW_OP_bregx); 820 OutStreamer.AddComment(Twine(Reg)); 821 EmitULEB128(Reg); 822 } 823 EmitSLEB128(Offset); 824 } else { 825 if (Reg < 32) { 826 OutStreamer.AddComment( 827 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg)); 828 EmitInt8(dwarf::DW_OP_reg0 + Reg); 829 } else { 830 OutStreamer.AddComment("DW_OP_regx"); 831 EmitInt8(dwarf::DW_OP_regx); 832 OutStreamer.AddComment(Twine(Reg)); 833 EmitULEB128(Reg); 834 } 835 } 836 837 // FIXME: Produce a DW_OP_bit_piece if we used a superregister 838} 839 840bool AsmPrinter::doFinalization(Module &M) { 841 // Emit global variables. 842 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 843 I != E; ++I) 844 EmitGlobalVariable(I); 845 846 // Emit visibility info for declarations 847 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 848 const Function &F = *I; 849 if (!F.isDeclaration()) 850 continue; 851 GlobalValue::VisibilityTypes V = F.getVisibility(); 852 if (V == GlobalValue::DefaultVisibility) 853 continue; 854 855 MCSymbol *Name = Mang->getSymbol(&F); 856 EmitVisibility(Name, V, false); 857 } 858 859 // Emit module flags. 860 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags; 861 M.getModuleFlagsMetadata(ModuleFlags); 862 if (!ModuleFlags.empty()) 863 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM); 864 865 // Finalize debug and EH information. 866 if (DE) { 867 { 868 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 869 DE->EndModule(); 870 } 871 delete DE; DE = 0; 872 } 873 if (DD) { 874 { 875 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 876 DD->endModule(); 877 } 878 delete DD; DD = 0; 879 } 880 881 // If the target wants to know about weak references, print them all. 882 if (MAI->getWeakRefDirective()) { 883 // FIXME: This is not lazy, it would be nice to only print weak references 884 // to stuff that is actually used. Note that doing so would require targets 885 // to notice uses in operands (due to constant exprs etc). This should 886 // happen with the MC stuff eventually. 887 888 // Print out module-level global variables here. 889 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 890 I != E; ++I) { 891 if (!I->hasExternalWeakLinkage()) continue; 892 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 893 } 894 895 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 896 if (!I->hasExternalWeakLinkage()) continue; 897 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 898 } 899 } 900 901 if (MAI->hasSetDirective()) { 902 OutStreamer.AddBlankLine(); 903 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 904 I != E; ++I) { 905 MCSymbol *Name = Mang->getSymbol(I); 906 907 const GlobalValue *GV = I->getAliasedGlobal(); 908 MCSymbol *Target = Mang->getSymbol(GV); 909 910 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 911 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 912 else if (I->hasWeakLinkage()) 913 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 914 else 915 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 916 917 EmitVisibility(Name, I->getVisibility()); 918 919 // Emit the directives as assignments aka .set: 920 OutStreamer.EmitAssignment(Name, 921 MCSymbolRefExpr::Create(Target, OutContext)); 922 } 923 } 924 925 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 926 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 927 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 928 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 929 MP->finishAssembly(*this); 930 931 // If we don't have any trampolines, then we don't require stack memory 932 // to be executable. Some targets have a directive to declare this. 933 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 934 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 935 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 936 OutStreamer.SwitchSection(S); 937 938 // Allow the target to emit any magic that it wants at the end of the file, 939 // after everything else has gone out. 940 EmitEndOfAsmFile(M); 941 942 delete Mang; Mang = 0; 943 MMI = 0; 944 945 OutStreamer.Finish(); 946 return false; 947} 948 949void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 950 this->MF = &MF; 951 // Get the function symbol. 952 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 953 CurrentFnSymForSize = CurrentFnSym; 954 955 if (isVerbose()) 956 LI = &getAnalysis<MachineLoopInfo>(); 957} 958 959namespace { 960 // SectionCPs - Keep track the alignment, constpool entries per Section. 961 struct SectionCPs { 962 const MCSection *S; 963 unsigned Alignment; 964 SmallVector<unsigned, 4> CPEs; 965 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 966 }; 967} 968 969/// EmitConstantPool - Print to the current output stream assembly 970/// representations of the constants in the constant pool MCP. This is 971/// used to print out constants which have been "spilled to memory" by 972/// the code generator. 973/// 974void AsmPrinter::EmitConstantPool() { 975 const MachineConstantPool *MCP = MF->getConstantPool(); 976 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 977 if (CP.empty()) return; 978 979 // Calculate sections for constant pool entries. We collect entries to go into 980 // the same section together to reduce amount of section switch statements. 981 SmallVector<SectionCPs, 4> CPSections; 982 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 983 const MachineConstantPoolEntry &CPE = CP[i]; 984 unsigned Align = CPE.getAlignment(); 985 986 SectionKind Kind; 987 switch (CPE.getRelocationInfo()) { 988 default: llvm_unreachable("Unknown section kind"); 989 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 990 case 1: 991 Kind = SectionKind::getReadOnlyWithRelLocal(); 992 break; 993 case 0: 994 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 995 case 4: Kind = SectionKind::getMergeableConst4(); break; 996 case 8: Kind = SectionKind::getMergeableConst8(); break; 997 case 16: Kind = SectionKind::getMergeableConst16();break; 998 default: Kind = SectionKind::getMergeableConst(); break; 999 } 1000 } 1001 1002 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 1003 1004 // The number of sections are small, just do a linear search from the 1005 // last section to the first. 1006 bool Found = false; 1007 unsigned SecIdx = CPSections.size(); 1008 while (SecIdx != 0) { 1009 if (CPSections[--SecIdx].S == S) { 1010 Found = true; 1011 break; 1012 } 1013 } 1014 if (!Found) { 1015 SecIdx = CPSections.size(); 1016 CPSections.push_back(SectionCPs(S, Align)); 1017 } 1018 1019 if (Align > CPSections[SecIdx].Alignment) 1020 CPSections[SecIdx].Alignment = Align; 1021 CPSections[SecIdx].CPEs.push_back(i); 1022 } 1023 1024 // Now print stuff into the calculated sections. 1025 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 1026 OutStreamer.SwitchSection(CPSections[i].S); 1027 EmitAlignment(Log2_32(CPSections[i].Alignment)); 1028 1029 unsigned Offset = 0; 1030 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 1031 unsigned CPI = CPSections[i].CPEs[j]; 1032 MachineConstantPoolEntry CPE = CP[CPI]; 1033 1034 // Emit inter-object padding for alignment. 1035 unsigned AlignMask = CPE.getAlignment() - 1; 1036 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 1037 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 1038 1039 Type *Ty = CPE.getType(); 1040 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 1041 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 1042 1043 if (CPE.isMachineConstantPoolEntry()) 1044 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 1045 else 1046 EmitGlobalConstant(CPE.Val.ConstVal); 1047 } 1048 } 1049} 1050 1051/// EmitJumpTableInfo - Print assembly representations of the jump tables used 1052/// by the current function to the current output stream. 1053/// 1054void AsmPrinter::EmitJumpTableInfo() { 1055 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1056 if (MJTI == 0) return; 1057 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1058 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1059 if (JT.empty()) return; 1060 1061 // Pick the directive to use to print the jump table entries, and switch to 1062 // the appropriate section. 1063 const Function *F = MF->getFunction(); 1064 bool JTInDiffSection = false; 1065 if (// In PIC mode, we need to emit the jump table to the same section as the 1066 // function body itself, otherwise the label differences won't make sense. 1067 // FIXME: Need a better predicate for this: what about custom entries? 1068 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1069 // We should also do if the section name is NULL or function is declared 1070 // in discardable section 1071 // FIXME: this isn't the right predicate, should be based on the MCSection 1072 // for the function. 1073 F->isWeakForLinker()) { 1074 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 1075 } else { 1076 // Otherwise, drop it in the readonly section. 1077 const MCSection *ReadOnlySection = 1078 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1079 OutStreamer.SwitchSection(ReadOnlySection); 1080 JTInDiffSection = true; 1081 } 1082 1083 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 1084 1085 // Jump tables in code sections are marked with a data_region directive 1086 // where that's supported. 1087 if (!JTInDiffSection) 1088 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32); 1089 1090 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1091 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1092 1093 // If this jump table was deleted, ignore it. 1094 if (JTBBs.empty()) continue; 1095 1096 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1097 // .set directive for each unique entry. This reduces the number of 1098 // relocations the assembler will generate for the jump table. 1099 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1100 MAI->hasSetDirective()) { 1101 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1102 const TargetLowering *TLI = TM.getTargetLowering(); 1103 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1104 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1105 const MachineBasicBlock *MBB = JTBBs[ii]; 1106 if (!EmittedSets.insert(MBB)) continue; 1107 1108 // .set LJTSet, LBB32-base 1109 const MCExpr *LHS = 1110 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1111 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1112 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1113 } 1114 } 1115 1116 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1117 // before each jump table. The first label is never referenced, but tells 1118 // the assembler and linker the extents of the jump table object. The 1119 // second label is actually referenced by the code. 1120 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1121 // FIXME: This doesn't have to have any specific name, just any randomly 1122 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1123 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1124 1125 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1126 1127 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1128 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1129 } 1130 if (!JTInDiffSection) 1131 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd); 1132} 1133 1134/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1135/// current stream. 1136void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1137 const MachineBasicBlock *MBB, 1138 unsigned UID) const { 1139 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1140 const MCExpr *Value = 0; 1141 switch (MJTI->getEntryKind()) { 1142 case MachineJumpTableInfo::EK_Inline: 1143 llvm_unreachable("Cannot emit EK_Inline jump table entry"); 1144 case MachineJumpTableInfo::EK_Custom32: 1145 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1146 OutContext); 1147 break; 1148 case MachineJumpTableInfo::EK_BlockAddress: 1149 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1150 // .word LBB123 1151 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1152 break; 1153 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1154 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1155 // with a relocation as gp-relative, e.g.: 1156 // .gprel32 LBB123 1157 MCSymbol *MBBSym = MBB->getSymbol(); 1158 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1159 return; 1160 } 1161 1162 case MachineJumpTableInfo::EK_GPRel64BlockAddress: { 1163 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded 1164 // with a relocation as gp-relative, e.g.: 1165 // .gpdword LBB123 1166 MCSymbol *MBBSym = MBB->getSymbol(); 1167 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1168 return; 1169 } 1170 1171 case MachineJumpTableInfo::EK_LabelDifference32: { 1172 // EK_LabelDifference32 - Each entry is the address of the block minus 1173 // the address of the jump table. This is used for PIC jump tables where 1174 // gprel32 is not supported. e.g.: 1175 // .word LBB123 - LJTI1_2 1176 // If the .set directive is supported, this is emitted as: 1177 // .set L4_5_set_123, LBB123 - LJTI1_2 1178 // .word L4_5_set_123 1179 1180 // If we have emitted set directives for the jump table entries, print 1181 // them rather than the entries themselves. If we're emitting PIC, then 1182 // emit the table entries as differences between two text section labels. 1183 if (MAI->hasSetDirective()) { 1184 // If we used .set, reference the .set's symbol. 1185 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1186 OutContext); 1187 break; 1188 } 1189 // Otherwise, use the difference as the jump table entry. 1190 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1191 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1192 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1193 break; 1194 } 1195 } 1196 1197 assert(Value && "Unknown entry kind!"); 1198 1199 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1200 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1201} 1202 1203 1204/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1205/// special global used by LLVM. If so, emit it and return true, otherwise 1206/// do nothing and return false. 1207bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1208 if (GV->getName() == "llvm.used") { 1209 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1210 EmitLLVMUsedList(GV->getInitializer()); 1211 return true; 1212 } 1213 1214 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1215 if (GV->getSection() == "llvm.metadata" || 1216 GV->hasAvailableExternallyLinkage()) 1217 return true; 1218 1219 if (!GV->hasAppendingLinkage()) return false; 1220 1221 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1222 1223 if (GV->getName() == "llvm.global_ctors") { 1224 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true); 1225 1226 if (TM.getRelocationModel() == Reloc::Static && 1227 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1228 StringRef Sym(".constructors_used"); 1229 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1230 MCSA_Reference); 1231 } 1232 return true; 1233 } 1234 1235 if (GV->getName() == "llvm.global_dtors") { 1236 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false); 1237 1238 if (TM.getRelocationModel() == Reloc::Static && 1239 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1240 StringRef Sym(".destructors_used"); 1241 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1242 MCSA_Reference); 1243 } 1244 return true; 1245 } 1246 1247 return false; 1248} 1249 1250/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1251/// global in the specified llvm.used list for which emitUsedDirectiveFor 1252/// is true, as being used with this directive. 1253void AsmPrinter::EmitLLVMUsedList(const Constant *List) { 1254 // Should be an array of 'i8*'. 1255 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1256 if (InitList == 0) return; 1257 1258 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1259 const GlobalValue *GV = 1260 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1261 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1262 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1263 } 1264} 1265 1266typedef std::pair<unsigned, Constant*> Structor; 1267 1268static bool priority_order(const Structor& lhs, const Structor& rhs) { 1269 return lhs.first < rhs.first; 1270} 1271 1272/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init 1273/// priority. 1274void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) { 1275 // Should be an array of '{ int, void ()* }' structs. The first value is the 1276 // init priority. 1277 if (!isa<ConstantArray>(List)) return; 1278 1279 // Sanity check the structors list. 1280 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1281 if (!InitList) return; // Not an array! 1282 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType()); 1283 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs! 1284 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) || 1285 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr). 1286 1287 // Gather the structors in a form that's convenient for sorting by priority. 1288 SmallVector<Structor, 8> Structors; 1289 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1290 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i)); 1291 if (!CS) continue; // Malformed. 1292 if (CS->getOperand(1)->isNullValue()) 1293 break; // Found a null terminator, skip the rest. 1294 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0)); 1295 if (!Priority) continue; // Malformed. 1296 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535), 1297 CS->getOperand(1))); 1298 } 1299 1300 // Emit the function pointers in the target-specific order 1301 const TargetData *TD = TM.getTargetData(); 1302 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1303 std::stable_sort(Structors.begin(), Structors.end(), priority_order); 1304 for (unsigned i = 0, e = Structors.size(); i != e; ++i) { 1305 const MCSection *OutputSection = 1306 (isCtor ? 1307 getObjFileLowering().getStaticCtorSection(Structors[i].first) : 1308 getObjFileLowering().getStaticDtorSection(Structors[i].first)); 1309 OutStreamer.SwitchSection(OutputSection); 1310 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection()) 1311 EmitAlignment(Align); 1312 EmitXXStructor(Structors[i].second); 1313 } 1314} 1315 1316//===--------------------------------------------------------------------===// 1317// Emission and print routines 1318// 1319 1320/// EmitInt8 - Emit a byte directive and value. 1321/// 1322void AsmPrinter::EmitInt8(int Value) const { 1323 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1324} 1325 1326/// EmitInt16 - Emit a short directive and value. 1327/// 1328void AsmPrinter::EmitInt16(int Value) const { 1329 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1330} 1331 1332/// EmitInt32 - Emit a long directive and value. 1333/// 1334void AsmPrinter::EmitInt32(int Value) const { 1335 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1336} 1337 1338/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1339/// in bytes of the directive is specified by Size and Hi/Lo specify the 1340/// labels. This implicitly uses .set if it is available. 1341void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1342 unsigned Size) const { 1343 // Get the Hi-Lo expression. 1344 const MCExpr *Diff = 1345 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1346 MCSymbolRefExpr::Create(Lo, OutContext), 1347 OutContext); 1348 1349 if (!MAI->hasSetDirective()) { 1350 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1351 return; 1352 } 1353 1354 // Otherwise, emit with .set (aka assignment). 1355 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1356 OutStreamer.EmitAssignment(SetLabel, Diff); 1357 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1358} 1359 1360/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1361/// where the size in bytes of the directive is specified by Size and Hi/Lo 1362/// specify the labels. This implicitly uses .set if it is available. 1363void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1364 const MCSymbol *Lo, unsigned Size) 1365 const { 1366 1367 // Emit Hi+Offset - Lo 1368 // Get the Hi+Offset expression. 1369 const MCExpr *Plus = 1370 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1371 MCConstantExpr::Create(Offset, OutContext), 1372 OutContext); 1373 1374 // Get the Hi+Offset-Lo expression. 1375 const MCExpr *Diff = 1376 MCBinaryExpr::CreateSub(Plus, 1377 MCSymbolRefExpr::Create(Lo, OutContext), 1378 OutContext); 1379 1380 if (!MAI->hasSetDirective()) 1381 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1382 else { 1383 // Otherwise, emit with .set (aka assignment). 1384 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1385 OutStreamer.EmitAssignment(SetLabel, Diff); 1386 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1387 } 1388} 1389 1390/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1391/// where the size in bytes of the directive is specified by Size and Label 1392/// specifies the label. This implicitly uses .set if it is available. 1393void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1394 unsigned Size) 1395 const { 1396 1397 // Emit Label+Offset (or just Label if Offset is zero) 1398 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext); 1399 if (Offset) 1400 Expr = MCBinaryExpr::CreateAdd(Expr, 1401 MCConstantExpr::Create(Offset, OutContext), 1402 OutContext); 1403 1404 OutStreamer.EmitValue(Expr, Size, 0/*AddrSpace*/); 1405} 1406 1407 1408//===----------------------------------------------------------------------===// 1409 1410// EmitAlignment - Emit an alignment directive to the specified power of 1411// two boundary. For example, if you pass in 3 here, you will get an 8 1412// byte alignment. If a global value is specified, and if that global has 1413// an explicit alignment requested, it will override the alignment request 1414// if required for correctness. 1415// 1416void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1417 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1418 1419 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1420 1421 if (getCurrentSection()->getKind().isText()) 1422 OutStreamer.EmitCodeAlignment(1 << NumBits); 1423 else 1424 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1425} 1426 1427//===----------------------------------------------------------------------===// 1428// Constant emission. 1429//===----------------------------------------------------------------------===// 1430 1431/// lowerConstant - Lower the specified LLVM Constant to an MCExpr. 1432/// 1433static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) { 1434 MCContext &Ctx = AP.OutContext; 1435 1436 if (CV->isNullValue() || isa<UndefValue>(CV)) 1437 return MCConstantExpr::Create(0, Ctx); 1438 1439 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1440 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1441 1442 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1443 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1444 1445 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1446 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1447 1448 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1449 if (CE == 0) { 1450 llvm_unreachable("Unknown constant value to lower!"); 1451 } 1452 1453 switch (CE->getOpcode()) { 1454 default: 1455 // If the code isn't optimized, there may be outstanding folding 1456 // opportunities. Attempt to fold the expression using TargetData as a 1457 // last resort before giving up. 1458 if (Constant *C = 1459 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1460 if (C != CE) 1461 return lowerConstant(C, AP); 1462 1463 // Otherwise report the problem to the user. 1464 { 1465 std::string S; 1466 raw_string_ostream OS(S); 1467 OS << "Unsupported expression in static initializer: "; 1468 WriteAsOperand(OS, CE, /*PrintType=*/false, 1469 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1470 report_fatal_error(OS.str()); 1471 } 1472 case Instruction::GetElementPtr: { 1473 const TargetData &TD = *AP.TM.getTargetData(); 1474 // Generate a symbolic expression for the byte address 1475 const Constant *PtrVal = CE->getOperand(0); 1476 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1477 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), IdxVec); 1478 1479 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP); 1480 if (Offset == 0) 1481 return Base; 1482 1483 // Truncate/sext the offset to the pointer size. 1484 unsigned Width = TD.getPointerSizeInBits(); 1485 if (Width < 64) 1486 Offset = SignExtend64(Offset, Width); 1487 1488 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1489 Ctx); 1490 } 1491 1492 case Instruction::Trunc: 1493 // We emit the value and depend on the assembler to truncate the generated 1494 // expression properly. This is important for differences between 1495 // blockaddress labels. Since the two labels are in the same function, it 1496 // is reasonable to treat their delta as a 32-bit value. 1497 // FALL THROUGH. 1498 case Instruction::BitCast: 1499 return lowerConstant(CE->getOperand(0), AP); 1500 1501 case Instruction::IntToPtr: { 1502 const TargetData &TD = *AP.TM.getTargetData(); 1503 // Handle casts to pointers by changing them into casts to the appropriate 1504 // integer type. This promotes constant folding and simplifies this code. 1505 Constant *Op = CE->getOperand(0); 1506 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1507 false/*ZExt*/); 1508 return lowerConstant(Op, AP); 1509 } 1510 1511 case Instruction::PtrToInt: { 1512 const TargetData &TD = *AP.TM.getTargetData(); 1513 // Support only foldable casts to/from pointers that can be eliminated by 1514 // changing the pointer to the appropriately sized integer type. 1515 Constant *Op = CE->getOperand(0); 1516 Type *Ty = CE->getType(); 1517 1518 const MCExpr *OpExpr = lowerConstant(Op, AP); 1519 1520 // We can emit the pointer value into this slot if the slot is an 1521 // integer slot equal to the size of the pointer. 1522 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1523 return OpExpr; 1524 1525 // Otherwise the pointer is smaller than the resultant integer, mask off 1526 // the high bits so we are sure to get a proper truncation if the input is 1527 // a constant expr. 1528 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1529 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1530 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1531 } 1532 1533 // The MC library also has a right-shift operator, but it isn't consistently 1534 // signed or unsigned between different targets. 1535 case Instruction::Add: 1536 case Instruction::Sub: 1537 case Instruction::Mul: 1538 case Instruction::SDiv: 1539 case Instruction::SRem: 1540 case Instruction::Shl: 1541 case Instruction::And: 1542 case Instruction::Or: 1543 case Instruction::Xor: { 1544 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP); 1545 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP); 1546 switch (CE->getOpcode()) { 1547 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1548 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1549 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1550 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1551 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1552 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1553 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1554 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1555 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1556 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1557 } 1558 } 1559 } 1560} 1561 1562static void emitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1563 AsmPrinter &AP); 1564 1565/// isRepeatedByteSequence - Determine whether the given value is 1566/// composed of a repeated sequence of identical bytes and return the 1567/// byte value. If it is not a repeated sequence, return -1. 1568static int isRepeatedByteSequence(const ConstantDataSequential *V) { 1569 StringRef Data = V->getRawDataValues(); 1570 assert(!Data.empty() && "Empty aggregates should be CAZ node"); 1571 char C = Data[0]; 1572 for (unsigned i = 1, e = Data.size(); i != e; ++i) 1573 if (Data[i] != C) return -1; 1574 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1. 1575} 1576 1577 1578/// isRepeatedByteSequence - Determine whether the given value is 1579/// composed of a repeated sequence of identical bytes and return the 1580/// byte value. If it is not a repeated sequence, return -1. 1581static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) { 1582 1583 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { 1584 if (CI->getBitWidth() > 64) return -1; 1585 1586 uint64_t Size = TM.getTargetData()->getTypeAllocSize(V->getType()); 1587 uint64_t Value = CI->getZExtValue(); 1588 1589 // Make sure the constant is at least 8 bits long and has a power 1590 // of 2 bit width. This guarantees the constant bit width is 1591 // always a multiple of 8 bits, avoiding issues with padding out 1592 // to Size and other such corner cases. 1593 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1; 1594 1595 uint8_t Byte = static_cast<uint8_t>(Value); 1596 1597 for (unsigned i = 1; i < Size; ++i) { 1598 Value >>= 8; 1599 if (static_cast<uint8_t>(Value) != Byte) return -1; 1600 } 1601 return Byte; 1602 } 1603 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) { 1604 // Make sure all array elements are sequences of the same repeated 1605 // byte. 1606 assert(CA->getNumOperands() != 0 && "Should be a CAZ"); 1607 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM); 1608 if (Byte == -1) return -1; 1609 1610 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) { 1611 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM); 1612 if (ThisByte == -1) return -1; 1613 if (Byte != ThisByte) return -1; 1614 } 1615 return Byte; 1616 } 1617 1618 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V)) 1619 return isRepeatedByteSequence(CDS); 1620 1621 return -1; 1622} 1623 1624static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS, 1625 unsigned AddrSpace,AsmPrinter &AP){ 1626 1627 // See if we can aggregate this into a .fill, if so, emit it as such. 1628 int Value = isRepeatedByteSequence(CDS, AP.TM); 1629 if (Value != -1) { 1630 uint64_t Bytes = AP.TM.getTargetData()->getTypeAllocSize(CDS->getType()); 1631 // Don't emit a 1-byte object as a .fill. 1632 if (Bytes > 1) 1633 return AP.OutStreamer.EmitFill(Bytes, Value, AddrSpace); 1634 } 1635 1636 // If this can be emitted with .ascii/.asciz, emit it as such. 1637 if (CDS->isString()) 1638 return AP.OutStreamer.EmitBytes(CDS->getAsString(), AddrSpace); 1639 1640 // Otherwise, emit the values in successive locations. 1641 unsigned ElementByteSize = CDS->getElementByteSize(); 1642 if (isa<IntegerType>(CDS->getElementType())) { 1643 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1644 if (AP.isVerbose()) 1645 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1646 CDS->getElementAsInteger(i)); 1647 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i), 1648 ElementByteSize, AddrSpace); 1649 } 1650 } else if (ElementByteSize == 4) { 1651 // FP Constants are printed as integer constants to avoid losing 1652 // precision. 1653 assert(CDS->getElementType()->isFloatTy()); 1654 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1655 union { 1656 float F; 1657 uint32_t I; 1658 }; 1659 1660 F = CDS->getElementAsFloat(i); 1661 if (AP.isVerbose()) 1662 AP.OutStreamer.GetCommentOS() << "float " << F << '\n'; 1663 AP.OutStreamer.EmitIntValue(I, 4, AddrSpace); 1664 } 1665 } else { 1666 assert(CDS->getElementType()->isDoubleTy()); 1667 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1668 union { 1669 double F; 1670 uint64_t I; 1671 }; 1672 1673 F = CDS->getElementAsDouble(i); 1674 if (AP.isVerbose()) 1675 AP.OutStreamer.GetCommentOS() << "double " << F << '\n'; 1676 AP.OutStreamer.EmitIntValue(I, 8, AddrSpace); 1677 } 1678 } 1679 1680 const TargetData &TD = *AP.TM.getTargetData(); 1681 unsigned Size = TD.getTypeAllocSize(CDS->getType()); 1682 unsigned EmittedSize = TD.getTypeAllocSize(CDS->getType()->getElementType()) * 1683 CDS->getNumElements(); 1684 if (unsigned Padding = Size - EmittedSize) 1685 AP.OutStreamer.EmitZeros(Padding, AddrSpace); 1686 1687} 1688 1689static void emitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1690 AsmPrinter &AP) { 1691 // See if we can aggregate some values. Make sure it can be 1692 // represented as a series of bytes of the constant value. 1693 int Value = isRepeatedByteSequence(CA, AP.TM); 1694 1695 if (Value != -1) { 1696 uint64_t Bytes = AP.TM.getTargetData()->getTypeAllocSize(CA->getType()); 1697 AP.OutStreamer.EmitFill(Bytes, Value, AddrSpace); 1698 } 1699 else { 1700 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1701 emitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1702 } 1703} 1704 1705static void emitGlobalConstantVector(const ConstantVector *CV, 1706 unsigned AddrSpace, AsmPrinter &AP) { 1707 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1708 emitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1709 1710 const TargetData &TD = *AP.TM.getTargetData(); 1711 unsigned Size = TD.getTypeAllocSize(CV->getType()); 1712 unsigned EmittedSize = TD.getTypeAllocSize(CV->getType()->getElementType()) * 1713 CV->getType()->getNumElements(); 1714 if (unsigned Padding = Size - EmittedSize) 1715 AP.OutStreamer.EmitZeros(Padding, AddrSpace); 1716} 1717 1718static void emitGlobalConstantStruct(const ConstantStruct *CS, 1719 unsigned AddrSpace, AsmPrinter &AP) { 1720 // Print the fields in successive locations. Pad to align if needed! 1721 const TargetData *TD = AP.TM.getTargetData(); 1722 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1723 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1724 uint64_t SizeSoFar = 0; 1725 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1726 const Constant *Field = CS->getOperand(i); 1727 1728 // Check if padding is needed and insert one or more 0s. 1729 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1730 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1731 - Layout->getElementOffset(i)) - FieldSize; 1732 SizeSoFar += FieldSize + PadSize; 1733 1734 // Now print the actual field value. 1735 emitGlobalConstantImpl(Field, AddrSpace, AP); 1736 1737 // Insert padding - this may include padding to increase the size of the 1738 // current field up to the ABI size (if the struct is not packed) as well 1739 // as padding to ensure that the next field starts at the right offset. 1740 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1741 } 1742 assert(SizeSoFar == Layout->getSizeInBytes() && 1743 "Layout of constant struct may be incorrect!"); 1744} 1745 1746static void emitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1747 AsmPrinter &AP) { 1748 if (CFP->getType()->isHalfTy()) { 1749 if (AP.isVerbose()) { 1750 SmallString<10> Str; 1751 CFP->getValueAPF().toString(Str); 1752 AP.OutStreamer.GetCommentOS() << "half " << Str << '\n'; 1753 } 1754 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1755 AP.OutStreamer.EmitIntValue(Val, 2, AddrSpace); 1756 return; 1757 } 1758 1759 if (CFP->getType()->isFloatTy()) { 1760 if (AP.isVerbose()) { 1761 float Val = CFP->getValueAPF().convertToFloat(); 1762 uint64_t IntVal = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1763 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n' 1764 << " (" << format("0x%x", IntVal) << ")\n"; 1765 } 1766 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1767 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1768 return; 1769 } 1770 1771 // FP Constants are printed as integer constants to avoid losing 1772 // precision. 1773 if (CFP->getType()->isDoubleTy()) { 1774 if (AP.isVerbose()) { 1775 double Val = CFP->getValueAPF().convertToDouble(); 1776 uint64_t IntVal = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1777 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n' 1778 << " (" << format("0x%lx", IntVal) << ")\n"; 1779 } 1780 1781 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1782 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1783 return; 1784 } 1785 1786 if (CFP->getType()->isX86_FP80Ty()) { 1787 // all long double variants are printed as hex 1788 // API needed to prevent premature destruction 1789 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1790 const uint64_t *p = API.getRawData(); 1791 if (AP.isVerbose()) { 1792 // Convert to double so we can print the approximate val as a comment. 1793 APFloat DoubleVal = CFP->getValueAPF(); 1794 bool ignored; 1795 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1796 &ignored); 1797 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1798 << DoubleVal.convertToDouble() << '\n'; 1799 } 1800 1801 if (AP.TM.getTargetData()->isBigEndian()) { 1802 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1803 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1804 } else { 1805 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1806 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1807 } 1808 1809 // Emit the tail padding for the long double. 1810 const TargetData &TD = *AP.TM.getTargetData(); 1811 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1812 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1813 return; 1814 } 1815 1816 assert(CFP->getType()->isPPC_FP128Ty() && 1817 "Floating point constant type not handled"); 1818 // All long double variants are printed as hex 1819 // API needed to prevent premature destruction. 1820 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1821 const uint64_t *p = API.getRawData(); 1822 if (AP.TM.getTargetData()->isBigEndian()) { 1823 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1824 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1825 } else { 1826 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1827 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1828 } 1829} 1830 1831static void emitGlobalConstantLargeInt(const ConstantInt *CI, 1832 unsigned AddrSpace, AsmPrinter &AP) { 1833 const TargetData *TD = AP.TM.getTargetData(); 1834 unsigned BitWidth = CI->getBitWidth(); 1835 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1836 1837 // We don't expect assemblers to support integer data directives 1838 // for more than 64 bits, so we emit the data in at most 64-bit 1839 // quantities at a time. 1840 const uint64_t *RawData = CI->getValue().getRawData(); 1841 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1842 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1843 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1844 } 1845} 1846 1847static void emitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1848 AsmPrinter &AP) { 1849 const TargetData *TD = AP.TM.getTargetData(); 1850 uint64_t Size = TD->getTypeAllocSize(CV->getType()); 1851 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) 1852 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1853 1854 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1855 switch (Size) { 1856 case 1: 1857 case 2: 1858 case 4: 1859 case 8: 1860 if (AP.isVerbose()) 1861 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1862 CI->getZExtValue()); 1863 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1864 return; 1865 default: 1866 emitGlobalConstantLargeInt(CI, AddrSpace, AP); 1867 return; 1868 } 1869 } 1870 1871 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1872 return emitGlobalConstantFP(CFP, AddrSpace, AP); 1873 1874 if (isa<ConstantPointerNull>(CV)) { 1875 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1876 return; 1877 } 1878 1879 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV)) 1880 return emitGlobalConstantDataSequential(CDS, AddrSpace, AP); 1881 1882 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1883 return emitGlobalConstantArray(CVA, AddrSpace, AP); 1884 1885 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1886 return emitGlobalConstantStruct(CVS, AddrSpace, AP); 1887 1888 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) { 1889 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of 1890 // vectors). 1891 if (CE->getOpcode() == Instruction::BitCast) 1892 return emitGlobalConstantImpl(CE->getOperand(0), AddrSpace, AP); 1893 1894 if (Size > 8) { 1895 // If the constant expression's size is greater than 64-bits, then we have 1896 // to emit the value in chunks. Try to constant fold the value and emit it 1897 // that way. 1898 Constant *New = ConstantFoldConstantExpression(CE, TD); 1899 if (New && New != CE) 1900 return emitGlobalConstantImpl(New, AddrSpace, AP); 1901 } 1902 } 1903 1904 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1905 return emitGlobalConstantVector(V, AddrSpace, AP); 1906 1907 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1908 // thread the streamer with EmitValue. 1909 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size, AddrSpace); 1910} 1911 1912/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1913void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1914 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1915 if (Size) 1916 emitGlobalConstantImpl(CV, AddrSpace, *this); 1917 else if (MAI->hasSubsectionsViaSymbols()) { 1918 // If the global has zero size, emit a single byte so that two labels don't 1919 // look like they are at the same location. 1920 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1921 } 1922} 1923 1924void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1925 // Target doesn't support this yet! 1926 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1927} 1928 1929void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1930 if (Offset > 0) 1931 OS << '+' << Offset; 1932 else if (Offset < 0) 1933 OS << Offset; 1934} 1935 1936//===----------------------------------------------------------------------===// 1937// Symbol Lowering Routines. 1938//===----------------------------------------------------------------------===// 1939 1940/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1941/// temporary label with the specified stem and unique ID. 1942MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1943 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1944 Name + Twine(ID)); 1945} 1946 1947/// GetTempSymbol - Return an assembler temporary label with the specified 1948/// stem. 1949MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1950 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1951 Name); 1952} 1953 1954 1955MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1956 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1957} 1958 1959MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1960 return MMI->getAddrLabelSymbol(BB); 1961} 1962 1963/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1964MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1965 return OutContext.GetOrCreateSymbol 1966 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1967 + "_" + Twine(CPID)); 1968} 1969 1970/// GetJTISymbol - Return the symbol for the specified jump table entry. 1971MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1972 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1973} 1974 1975/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1976/// FIXME: privatize to AsmPrinter. 1977MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1978 return OutContext.GetOrCreateSymbol 1979 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1980 Twine(UID) + "_set_" + Twine(MBBID)); 1981} 1982 1983/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1984/// global value name as its base, with the specified suffix, and where the 1985/// symbol is forced to have private linkage if ForcePrivate is true. 1986MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1987 StringRef Suffix, 1988 bool ForcePrivate) const { 1989 SmallString<60> NameStr; 1990 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1991 NameStr.append(Suffix.begin(), Suffix.end()); 1992 return OutContext.GetOrCreateSymbol(NameStr.str()); 1993} 1994 1995/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1996/// ExternalSymbol. 1997MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1998 SmallString<60> NameStr; 1999 Mang->getNameWithPrefix(NameStr, Sym); 2000 return OutContext.GetOrCreateSymbol(NameStr.str()); 2001} 2002 2003 2004 2005/// PrintParentLoopComment - Print comments about parent loops of this one. 2006static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2007 unsigned FunctionNumber) { 2008 if (Loop == 0) return; 2009 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 2010 OS.indent(Loop->getLoopDepth()*2) 2011 << "Parent Loop BB" << FunctionNumber << "_" 2012 << Loop->getHeader()->getNumber() 2013 << " Depth=" << Loop->getLoopDepth() << '\n'; 2014} 2015 2016 2017/// PrintChildLoopComment - Print comments about child loops within 2018/// the loop for this basic block, with nesting. 2019static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2020 unsigned FunctionNumber) { 2021 // Add child loop information 2022 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 2023 OS.indent((*CL)->getLoopDepth()*2) 2024 << "Child Loop BB" << FunctionNumber << "_" 2025 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 2026 << '\n'; 2027 PrintChildLoopComment(OS, *CL, FunctionNumber); 2028 } 2029} 2030 2031/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks. 2032static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB, 2033 const MachineLoopInfo *LI, 2034 const AsmPrinter &AP) { 2035 // Add loop depth information 2036 const MachineLoop *Loop = LI->getLoopFor(&MBB); 2037 if (Loop == 0) return; 2038 2039 MachineBasicBlock *Header = Loop->getHeader(); 2040 assert(Header && "No header for loop"); 2041 2042 // If this block is not a loop header, just print out what is the loop header 2043 // and return. 2044 if (Header != &MBB) { 2045 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 2046 Twine(AP.getFunctionNumber())+"_" + 2047 Twine(Loop->getHeader()->getNumber())+ 2048 " Depth="+Twine(Loop->getLoopDepth())); 2049 return; 2050 } 2051 2052 // Otherwise, it is a loop header. Print out information about child and 2053 // parent loops. 2054 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 2055 2056 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 2057 2058 OS << "=>"; 2059 OS.indent(Loop->getLoopDepth()*2-2); 2060 2061 OS << "This "; 2062 if (Loop->empty()) 2063 OS << "Inner "; 2064 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 2065 2066 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 2067} 2068 2069 2070/// EmitBasicBlockStart - This method prints the label for the specified 2071/// MachineBasicBlock, an alignment (if present) and a comment describing 2072/// it if appropriate. 2073void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 2074 // Emit an alignment directive for this block, if needed. 2075 if (unsigned Align = MBB->getAlignment()) 2076 EmitAlignment(Align); 2077 2078 // If the block has its address taken, emit any labels that were used to 2079 // reference the block. It is possible that there is more than one label 2080 // here, because multiple LLVM BB's may have been RAUW'd to this block after 2081 // the references were generated. 2082 if (MBB->hasAddressTaken()) { 2083 const BasicBlock *BB = MBB->getBasicBlock(); 2084 if (isVerbose()) 2085 OutStreamer.AddComment("Block address taken"); 2086 2087 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 2088 2089 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 2090 OutStreamer.EmitLabel(Syms[i]); 2091 } 2092 2093 // Print some verbose block comments. 2094 if (isVerbose()) { 2095 if (const BasicBlock *BB = MBB->getBasicBlock()) 2096 if (BB->hasName()) 2097 OutStreamer.AddComment("%" + BB->getName()); 2098 emitBasicBlockLoopComments(*MBB, LI, *this); 2099 } 2100 2101 // Print the main label for the block. 2102 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 2103 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 2104 // NOTE: Want this comment at start of line, don't emit with AddComment. 2105 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 2106 Twine(MBB->getNumber()) + ":"); 2107 } 2108 } else { 2109 OutStreamer.EmitLabel(MBB->getSymbol()); 2110 } 2111} 2112 2113void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 2114 bool IsDefinition) const { 2115 MCSymbolAttr Attr = MCSA_Invalid; 2116 2117 switch (Visibility) { 2118 default: break; 2119 case GlobalValue::HiddenVisibility: 2120 if (IsDefinition) 2121 Attr = MAI->getHiddenVisibilityAttr(); 2122 else 2123 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 2124 break; 2125 case GlobalValue::ProtectedVisibility: 2126 Attr = MAI->getProtectedVisibilityAttr(); 2127 break; 2128 } 2129 2130 if (Attr != MCSA_Invalid) 2131 OutStreamer.EmitSymbolAttribute(Sym, Attr); 2132} 2133 2134/// isBlockOnlyReachableByFallthough - Return true if the basic block has 2135/// exactly one predecessor and the control transfer mechanism between 2136/// the predecessor and this block is a fall-through. 2137bool AsmPrinter:: 2138isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 2139 // If this is a landing pad, it isn't a fall through. If it has no preds, 2140 // then nothing falls through to it. 2141 if (MBB->isLandingPad() || MBB->pred_empty()) 2142 return false; 2143 2144 // If there isn't exactly one predecessor, it can't be a fall through. 2145 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 2146 ++PI2; 2147 if (PI2 != MBB->pred_end()) 2148 return false; 2149 2150 // The predecessor has to be immediately before this block. 2151 MachineBasicBlock *Pred = *PI; 2152 2153 if (!Pred->isLayoutSuccessor(MBB)) 2154 return false; 2155 2156 // If the block is completely empty, then it definitely does fall through. 2157 if (Pred->empty()) 2158 return true; 2159 2160 // Check the terminators in the previous blocks 2161 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(), 2162 IE = Pred->end(); II != IE; ++II) { 2163 MachineInstr &MI = *II; 2164 2165 // If it is not a simple branch, we are in a table somewhere. 2166 if (!MI.isBranch() || MI.isIndirectBranch()) 2167 return false; 2168 2169 // If we are the operands of one of the branches, this is not 2170 // a fall through. 2171 for (MachineInstr::mop_iterator OI = MI.operands_begin(), 2172 OE = MI.operands_end(); OI != OE; ++OI) { 2173 const MachineOperand& OP = *OI; 2174 if (OP.isJTI()) 2175 return false; 2176 if (OP.isMBB() && OP.getMBB() == MBB) 2177 return false; 2178 } 2179 } 2180 2181 return true; 2182} 2183 2184 2185 2186GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 2187 if (!S->usesMetadata()) 2188 return 0; 2189 2190 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 2191 gcp_map_type::iterator GCPI = GCMap.find(S); 2192 if (GCPI != GCMap.end()) 2193 return GCPI->second; 2194 2195 const char *Name = S->getName().c_str(); 2196 2197 for (GCMetadataPrinterRegistry::iterator 2198 I = GCMetadataPrinterRegistry::begin(), 2199 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 2200 if (strcmp(Name, I->getName()) == 0) { 2201 GCMetadataPrinter *GMP = I->instantiate(); 2202 GMP->S = S; 2203 GCMap.insert(std::make_pair(S, GMP)); 2204 return GMP; 2205 } 2206 2207 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 2208} 2209