AsmPrinter.cpp revision 3d47402f2e8701c7ed340884720cc99727bd7f85
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/ADT/SmallString.h" 19#include "llvm/ADT/Statistic.h" 20#include "llvm/Analysis/ConstantFolding.h" 21#include "llvm/Assembly/Writer.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/MachineJumpTableInfo.h" 27#include "llvm/CodeGen/MachineLoopInfo.h" 28#include "llvm/CodeGen/MachineModuleInfo.h" 29#include "llvm/DebugInfo.h" 30#include "llvm/IR/DataLayout.h" 31#include "llvm/IR/Module.h" 32#include "llvm/IR/Operator.h" 33#include "llvm/MC/MCAsmInfo.h" 34#include "llvm/MC/MCContext.h" 35#include "llvm/MC/MCExpr.h" 36#include "llvm/MC/MCInst.h" 37#include "llvm/MC/MCSection.h" 38#include "llvm/MC/MCStreamer.h" 39#include "llvm/MC/MCSymbol.h" 40#include "llvm/Support/ErrorHandling.h" 41#include "llvm/Support/Format.h" 42#include "llvm/Support/MathExtras.h" 43#include "llvm/Support/Timer.h" 44#include "llvm/Target/Mangler.h" 45#include "llvm/Target/TargetFrameLowering.h" 46#include "llvm/Target/TargetInstrInfo.h" 47#include "llvm/Target/TargetLowering.h" 48#include "llvm/Target/TargetLoweringObjectFile.h" 49#include "llvm/Target/TargetOptions.h" 50#include "llvm/Target/TargetRegisterInfo.h" 51#include "llvm/Transforms/Utils/GlobalStatus.h" 52using namespace llvm; 53 54static const char *const DWARFGroupName = "DWARF Emission"; 55static const char *const DbgTimerName = "DWARF Debug Writer"; 56static const char *const EHTimerName = "DWARF Exception Writer"; 57 58STATISTIC(EmittedInsts, "Number of machine instrs printed"); 59 60char AsmPrinter::ID = 0; 61 62typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 63static gcp_map_type &getGCMap(void *&P) { 64 if (P == 0) 65 P = new gcp_map_type(); 66 return *(gcp_map_type*)P; 67} 68 69 70/// getGVAlignmentLog2 - Return the alignment to use for the specified global 71/// value in log2 form. This rounds up to the preferred alignment if possible 72/// and legal. 73static unsigned getGVAlignmentLog2(const GlobalValue *GV, const DataLayout &TD, 74 unsigned InBits = 0) { 75 unsigned NumBits = 0; 76 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 77 NumBits = TD.getPreferredAlignmentLog(GVar); 78 79 // If InBits is specified, round it to it. 80 if (InBits > NumBits) 81 NumBits = InBits; 82 83 // If the GV has a specified alignment, take it into account. 84 if (GV->getAlignment() == 0) 85 return NumBits; 86 87 unsigned GVAlign = Log2_32(GV->getAlignment()); 88 89 // If the GVAlign is larger than NumBits, or if we are required to obey 90 // NumBits because the GV has an assigned section, obey it. 91 if (GVAlign > NumBits || GV->hasSection()) 92 NumBits = GVAlign; 93 return NumBits; 94} 95 96AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 97 : MachineFunctionPass(ID), 98 TM(tm), MAI(tm.getMCAsmInfo()), MII(tm.getInstrInfo()), 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; MF = 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/// getDataLayout - Return information about data layout. 134const DataLayout &AsmPrinter::getDataLayout() const { 135 return *TM.getDataLayout(); 136} 137 138StringRef AsmPrinter::getTargetTriple() const { 139 return TM.getTargetTriple(); 140} 141 142/// getCurrentSection() - Return the current section we are emitting to. 143const MCSection *AsmPrinter::getCurrentSection() const { 144 return OutStreamer.getCurrentSection().first; 145} 146 147 148 149void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 150 AU.setPreservesAll(); 151 MachineFunctionPass::getAnalysisUsage(AU); 152 AU.addRequired<MachineModuleInfo>(); 153 AU.addRequired<GCModuleInfo>(); 154 if (isVerbose()) 155 AU.addRequired<MachineLoopInfo>(); 156} 157 158bool AsmPrinter::doInitialization(Module &M) { 159 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 160 MMI->AnalyzeModule(M); 161 162 // Initialize TargetLoweringObjectFile. 163 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 164 .Initialize(OutContext, TM); 165 166 OutStreamer.InitStreamer(); 167 168 Mang = new Mangler(&TM); 169 170 // Allow the target to emit any magic that it wants at the start of the file. 171 EmitStartOfAsmFile(M); 172 173 // Very minimal debug info. It is ignored if we emit actual debug info. If we 174 // don't, this at least helps the user find where a global came from. 175 if (MAI->hasSingleParameterDotFile()) { 176 // .file "foo.c" 177 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 178 } 179 180 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 181 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 182 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 183 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 184 MP->beginAssembly(*this); 185 186 // Emit module-level inline asm if it exists. 187 if (!M.getModuleInlineAsm().empty()) { 188 OutStreamer.AddComment("Start of file scope inline assembly"); 189 OutStreamer.AddBlankLine(); 190 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 191 OutStreamer.AddComment("End of file scope inline assembly"); 192 OutStreamer.AddBlankLine(); 193 } 194 195 if (MAI->doesSupportDebugInformation()) 196 DD = new DwarfDebug(this, &M); 197 198 switch (MAI->getExceptionHandlingType()) { 199 case ExceptionHandling::None: 200 return false; 201 case ExceptionHandling::SjLj: 202 case ExceptionHandling::DwarfCFI: 203 DE = new DwarfCFIException(this); 204 return false; 205 case ExceptionHandling::ARM: 206 DE = new ARMException(this); 207 return false; 208 case ExceptionHandling::Win64: 209 DE = new Win64Exception(this); 210 return false; 211 } 212 213 llvm_unreachable("Unknown exception type."); 214} 215 216void AsmPrinter::EmitLinkage(const GlobalValue *GV, MCSymbol *GVSym) const { 217 GlobalValue::LinkageTypes Linkage = GV->getLinkage(); 218 switch (Linkage) { 219 case GlobalValue::CommonLinkage: 220 case GlobalValue::LinkOnceAnyLinkage: 221 case GlobalValue::LinkOnceODRLinkage: 222 case GlobalValue::WeakAnyLinkage: 223 case GlobalValue::WeakODRLinkage: 224 case GlobalValue::LinkerPrivateWeakLinkage: 225 if (MAI->getWeakDefDirective() != 0) { 226 // .globl _foo 227 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 228 229 bool CanBeHidden = false; 230 231 if (Linkage == GlobalValue::LinkOnceODRLinkage) { 232 if (GV->hasUnnamedAddr()) { 233 CanBeHidden = true; 234 } else { 235 GlobalStatus GS; 236 if (!GlobalStatus::analyzeGlobal(GV, GS) && !GS.IsCompared) 237 CanBeHidden = true; 238 } 239 } 240 241 if (!CanBeHidden) 242 // .weak_definition _foo 243 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 244 else 245 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 246 } else if (MAI->getLinkOnceDirective() != 0) { 247 // .globl _foo 248 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 249 //NOTE: linkonce is handled by the section the symbol was assigned to. 250 } else { 251 // .weak _foo 252 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 253 } 254 return; 255 case GlobalValue::DLLExportLinkage: 256 case GlobalValue::AppendingLinkage: 257 // FIXME: appending linkage variables should go into a section of 258 // their name or something. For now, just emit them as external. 259 case GlobalValue::ExternalLinkage: 260 // If external or appending, declare as a global symbol. 261 // .globl _foo 262 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 263 return; 264 case GlobalValue::PrivateLinkage: 265 case GlobalValue::InternalLinkage: 266 case GlobalValue::LinkerPrivateLinkage: 267 return; 268 case GlobalValue::AvailableExternallyLinkage: 269 llvm_unreachable("Should never emit this"); 270 case GlobalValue::DLLImportLinkage: 271 case GlobalValue::ExternalWeakLinkage: 272 llvm_unreachable("Don't know how to emit these"); 273 } 274 llvm_unreachable("Unknown linkage type!"); 275} 276 277MCSymbol *AsmPrinter::getSymbol(const GlobalValue *GV) const { 278 return getObjFileLowering().getSymbol(*Mang, GV); 279} 280 281/// EmitGlobalVariable - Emit the specified global variable to the .s file. 282void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 283 if (GV->hasInitializer()) { 284 // Check to see if this is a special global used by LLVM, if so, emit it. 285 if (EmitSpecialLLVMGlobal(GV)) 286 return; 287 288 if (isVerbose()) { 289 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 290 /*PrintType=*/false, GV->getParent()); 291 OutStreamer.GetCommentOS() << '\n'; 292 } 293 } 294 295 MCSymbol *GVSym = getSymbol(GV); 296 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration()); 297 298 if (!GV->hasInitializer()) // External globals require no extra code. 299 return; 300 301 if (MAI->hasDotTypeDotSizeDirective()) 302 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 303 304 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 305 306 const DataLayout *DL = TM.getDataLayout(); 307 uint64_t Size = DL->getTypeAllocSize(GV->getType()->getElementType()); 308 309 // If the alignment is specified, we *must* obey it. Overaligning a global 310 // with a specified alignment is a prompt way to break globals emitted to 311 // sections and expected to be contiguous (e.g. ObjC metadata). 312 unsigned AlignLog = getGVAlignmentLog2(GV, *DL); 313 314 if (DD) 315 DD->setSymbolSize(GVSym, Size); 316 317 // Handle common and BSS local symbols (.lcomm). 318 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 319 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 320 unsigned Align = 1 << AlignLog; 321 322 // Handle common symbols. 323 if (GVKind.isCommon()) { 324 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 325 Align = 0; 326 327 // .comm _foo, 42, 4 328 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 329 return; 330 } 331 332 // Handle local BSS symbols. 333 if (MAI->hasMachoZeroFillDirective()) { 334 const MCSection *TheSection = 335 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 336 // .zerofill __DATA, __bss, _foo, 400, 5 337 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align); 338 return; 339 } 340 341 // Use .lcomm only if it supports user-specified alignment. 342 // Otherwise, while it would still be correct to use .lcomm in some 343 // cases (e.g. when Align == 1), the external assembler might enfore 344 // some -unknown- default alignment behavior, which could cause 345 // spurious differences between external and integrated assembler. 346 // Prefer to simply fall back to .local / .comm in this case. 347 if (MAI->getLCOMMDirectiveAlignmentType() != LCOMM::NoAlignment) { 348 // .lcomm _foo, 42 349 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align); 350 return; 351 } 352 353 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 354 Align = 0; 355 356 // .local _foo 357 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 358 // .comm _foo, 42, 4 359 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 360 return; 361 } 362 363 const MCSection *TheSection = 364 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 365 366 // Handle the zerofill directive on darwin, which is a special form of BSS 367 // emission. 368 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 369 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 370 371 // .globl _foo 372 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 373 // .zerofill __DATA, __common, _foo, 400, 5 374 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 375 return; 376 } 377 378 // Handle thread local data for mach-o which requires us to output an 379 // additional structure of data and mangle the original symbol so that we 380 // can reference it later. 381 // 382 // TODO: This should become an "emit thread local global" method on TLOF. 383 // All of this macho specific stuff should be sunk down into TLOFMachO and 384 // stuff like "TLSExtraDataSection" should no longer be part of the parent 385 // TLOF class. This will also make it more obvious that stuff like 386 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 387 // specific code. 388 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 389 // Emit the .tbss symbol 390 MCSymbol *MangSym = 391 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 392 393 if (GVKind.isThreadBSS()) { 394 TheSection = getObjFileLowering().getTLSBSSSection(); 395 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 396 } else if (GVKind.isThreadData()) { 397 OutStreamer.SwitchSection(TheSection); 398 399 EmitAlignment(AlignLog, GV); 400 OutStreamer.EmitLabel(MangSym); 401 402 EmitGlobalConstant(GV->getInitializer()); 403 } 404 405 OutStreamer.AddBlankLine(); 406 407 // Emit the variable struct for the runtime. 408 const MCSection *TLVSect 409 = getObjFileLowering().getTLSExtraDataSection(); 410 411 OutStreamer.SwitchSection(TLVSect); 412 // Emit the linkage here. 413 EmitLinkage(GV, GVSym); 414 OutStreamer.EmitLabel(GVSym); 415 416 // Three pointers in size: 417 // - __tlv_bootstrap - used to make sure support exists 418 // - spare pointer, used when mapped by the runtime 419 // - pointer to mangled symbol above with initializer 420 unsigned PtrSize = DL->getPointerTypeSize(GV->getType()); 421 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 422 PtrSize); 423 OutStreamer.EmitIntValue(0, PtrSize); 424 OutStreamer.EmitSymbolValue(MangSym, PtrSize); 425 426 OutStreamer.AddBlankLine(); 427 return; 428 } 429 430 OutStreamer.SwitchSection(TheSection); 431 432 EmitLinkage(GV, GVSym); 433 EmitAlignment(AlignLog, GV); 434 435 OutStreamer.EmitLabel(GVSym); 436 437 EmitGlobalConstant(GV->getInitializer()); 438 439 if (MAI->hasDotTypeDotSizeDirective()) 440 // .size foo, 42 441 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 442 443 OutStreamer.AddBlankLine(); 444} 445 446/// EmitFunctionHeader - This method emits the header for the current 447/// function. 448void AsmPrinter::EmitFunctionHeader() { 449 // Print out constants referenced by the function 450 EmitConstantPool(); 451 452 // Print the 'header' of function. 453 const Function *F = MF->getFunction(); 454 455 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 456 EmitVisibility(CurrentFnSym, F->getVisibility()); 457 458 EmitLinkage(F, CurrentFnSym); 459 EmitAlignment(MF->getAlignment(), F); 460 461 if (MAI->hasDotTypeDotSizeDirective()) 462 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 463 464 if (isVerbose()) { 465 WriteAsOperand(OutStreamer.GetCommentOS(), F, 466 /*PrintType=*/false, F->getParent()); 467 OutStreamer.GetCommentOS() << '\n'; 468 } 469 470 // Emit the CurrentFnSym. This is a virtual function to allow targets to 471 // do their wild and crazy things as required. 472 EmitFunctionEntryLabel(); 473 474 // If the function had address-taken blocks that got deleted, then we have 475 // references to the dangling symbols. Emit them at the start of the function 476 // so that we don't get references to undefined symbols. 477 std::vector<MCSymbol*> DeadBlockSyms; 478 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 479 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 480 OutStreamer.AddComment("Address taken block that was later removed"); 481 OutStreamer.EmitLabel(DeadBlockSyms[i]); 482 } 483 484 // Emit pre-function debug and/or EH information. 485 if (DE) { 486 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 487 DE->BeginFunction(MF); 488 } 489 if (DD) { 490 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 491 DD->beginFunction(MF); 492 } 493 494 // Emit the prefix data. 495 if (F->hasPrefixData()) 496 EmitGlobalConstant(F->getPrefixData()); 497} 498 499/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 500/// function. This can be overridden by targets as required to do custom stuff. 501void AsmPrinter::EmitFunctionEntryLabel() { 502 // The function label could have already been emitted if two symbols end up 503 // conflicting due to asm renaming. Detect this and emit an error. 504 if (CurrentFnSym->isUndefined()) 505 return OutStreamer.EmitLabel(CurrentFnSym); 506 507 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 508 "' label emitted multiple times to assembly file"); 509} 510 511/// emitComments - Pretty-print comments for instructions. 512static void emitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 513 const MachineFunction *MF = MI.getParent()->getParent(); 514 const TargetMachine &TM = MF->getTarget(); 515 516 // Check for spills and reloads 517 int FI; 518 519 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 520 521 // We assume a single instruction only has a spill or reload, not 522 // both. 523 const MachineMemOperand *MMO; 524 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 525 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 526 MMO = *MI.memoperands_begin(); 527 CommentOS << MMO->getSize() << "-byte Reload\n"; 528 } 529 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 530 if (FrameInfo->isSpillSlotObjectIndex(FI)) 531 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 532 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 533 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 534 MMO = *MI.memoperands_begin(); 535 CommentOS << MMO->getSize() << "-byte Spill\n"; 536 } 537 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 538 if (FrameInfo->isSpillSlotObjectIndex(FI)) 539 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 540 } 541 542 // Check for spill-induced copies 543 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 544 CommentOS << " Reload Reuse\n"; 545} 546 547/// emitImplicitDef - This method emits the specified machine instruction 548/// that is an implicit def. 549void AsmPrinter::emitImplicitDef(const MachineInstr *MI) const { 550 unsigned RegNo = MI->getOperand(0).getReg(); 551 OutStreamer.AddComment(Twine("implicit-def: ") + 552 TM.getRegisterInfo()->getName(RegNo)); 553 OutStreamer.AddBlankLine(); 554} 555 556static void emitKill(const MachineInstr *MI, AsmPrinter &AP) { 557 std::string Str = "kill:"; 558 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 559 const MachineOperand &Op = MI->getOperand(i); 560 assert(Op.isReg() && "KILL instruction must have only register operands"); 561 Str += ' '; 562 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 563 Str += (Op.isDef() ? "<def>" : "<kill>"); 564 } 565 AP.OutStreamer.AddComment(Str); 566 AP.OutStreamer.AddBlankLine(); 567} 568 569/// emitDebugValueComment - This method handles the target-independent form 570/// of DBG_VALUE, returning true if it was able to do so. A false return 571/// means the target will need to handle MI in EmitInstruction. 572static bool emitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 573 // This code handles only the 3-operand target-independent form. 574 if (MI->getNumOperands() != 3) 575 return false; 576 577 SmallString<128> Str; 578 raw_svector_ostream OS(Str); 579 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 580 581 // cast away const; DIetc do not take const operands for some reason. 582 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 583 if (V.getContext().isSubprogram()) { 584 StringRef Name = DISubprogram(V.getContext()).getDisplayName(); 585 if (!Name.empty()) 586 OS << Name << ":"; 587 } 588 OS << V.getName() << " <- "; 589 590 // The second operand is only an offset if it's an immediate. 591 bool Deref = MI->getOperand(0).isReg() && MI->getOperand(1).isImm(); 592 int64_t Offset = Deref ? MI->getOperand(1).getImm() : 0; 593 594 // Register or immediate value. Register 0 means undef. 595 if (MI->getOperand(0).isFPImm()) { 596 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 597 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 598 OS << (double)APF.convertToFloat(); 599 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 600 OS << APF.convertToDouble(); 601 } else { 602 // There is no good way to print long double. Convert a copy to 603 // double. Ah well, it's only a comment. 604 bool ignored; 605 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 606 &ignored); 607 OS << "(long double) " << APF.convertToDouble(); 608 } 609 } else if (MI->getOperand(0).isImm()) { 610 OS << MI->getOperand(0).getImm(); 611 } else if (MI->getOperand(0).isCImm()) { 612 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/); 613 } else { 614 unsigned Reg; 615 if (MI->getOperand(0).isReg()) { 616 Reg = MI->getOperand(0).getReg(); 617 } else { 618 assert(MI->getOperand(0).isFI() && "Unknown operand type"); 619 const TargetFrameLowering *TFI = AP.TM.getFrameLowering(); 620 Offset += TFI->getFrameIndexReference(*AP.MF, 621 MI->getOperand(0).getIndex(), Reg); 622 Deref = true; 623 } 624 if (Reg == 0) { 625 // Suppress offset, it is not meaningful here. 626 OS << "undef"; 627 // NOTE: Want this comment at start of line, don't emit with AddComment. 628 AP.OutStreamer.EmitRawText(OS.str()); 629 return true; 630 } 631 if (Deref) 632 OS << '['; 633 OS << AP.TM.getRegisterInfo()->getName(Reg); 634 } 635 636 if (Deref) 637 OS << '+' << Offset << ']'; 638 639 // NOTE: Want this comment at start of line, don't emit with AddComment. 640 AP.OutStreamer.EmitRawText(OS.str()); 641 return true; 642} 643 644AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() { 645 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI && 646 MF->getFunction()->needsUnwindTableEntry()) 647 return CFI_M_EH; 648 649 if (MMI->hasDebugInfo()) 650 return CFI_M_Debug; 651 652 return CFI_M_None; 653} 654 655bool AsmPrinter::needsSEHMoves() { 656 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 && 657 MF->getFunction()->needsUnwindTableEntry(); 658} 659 660bool AsmPrinter::needsRelocationsForDwarfStringPool() const { 661 return MAI->doesDwarfUseRelocationsAcrossSections(); 662} 663 664void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 665 const MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 666 667 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) 668 return; 669 670 if (needsCFIMoves() == CFI_M_None) 671 return; 672 673 if (MMI->getCompactUnwindEncoding() != 0) 674 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding()); 675 676 const MachineModuleInfo &MMI = MF->getMMI(); 677 const std::vector<MCCFIInstruction> &Instrs = MMI.getFrameInstructions(); 678 bool FoundOne = false; 679 (void)FoundOne; 680 for (std::vector<MCCFIInstruction>::const_iterator I = Instrs.begin(), 681 E = Instrs.end(); I != E; ++I) { 682 if (I->getLabel() == Label) { 683 emitCFIInstruction(*I); 684 FoundOne = true; 685 } 686 } 687 assert(FoundOne); 688} 689 690/// EmitFunctionBody - This method emits the body and trailer for a 691/// function. 692void AsmPrinter::EmitFunctionBody() { 693 // Emit target-specific gunk before the function body. 694 EmitFunctionBodyStart(); 695 696 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 697 698 // Print out code for the function. 699 bool HasAnyRealCode = false; 700 const MachineInstr *LastMI = 0; 701 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 702 I != E; ++I) { 703 // Print a label for the basic block. 704 EmitBasicBlockStart(I); 705 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 706 II != IE; ++II) { 707 LastMI = II; 708 709 // Print the assembly for the instruction. 710 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 711 !II->isDebugValue()) { 712 HasAnyRealCode = true; 713 ++EmittedInsts; 714 } 715 716 if (ShouldPrintDebugScopes) { 717 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 718 DD->beginInstruction(II); 719 } 720 721 if (isVerbose()) 722 emitComments(*II, OutStreamer.GetCommentOS()); 723 724 switch (II->getOpcode()) { 725 case TargetOpcode::PROLOG_LABEL: 726 emitPrologLabel(*II); 727 break; 728 729 case TargetOpcode::EH_LABEL: 730 case TargetOpcode::GC_LABEL: 731 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 732 break; 733 case TargetOpcode::INLINEASM: 734 EmitInlineAsm(II); 735 break; 736 case TargetOpcode::DBG_VALUE: 737 if (isVerbose()) { 738 if (!emitDebugValueComment(II, *this)) 739 EmitInstruction(II); 740 } 741 break; 742 case TargetOpcode::IMPLICIT_DEF: 743 if (isVerbose()) emitImplicitDef(II); 744 break; 745 case TargetOpcode::KILL: 746 if (isVerbose()) emitKill(II, *this); 747 break; 748 default: 749 if (!TM.hasMCUseLoc()) 750 MCLineEntry::Make(&OutStreamer, getCurrentSection()); 751 752 EmitInstruction(II); 753 break; 754 } 755 756 if (ShouldPrintDebugScopes) { 757 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 758 DD->endInstruction(II); 759 } 760 } 761 } 762 763 // If the last instruction was a prolog label, then we have a situation where 764 // we emitted a prolog but no function body. This results in the ending prolog 765 // label equaling the end of function label and an invalid "row" in the 766 // FDE. We need to emit a noop in this situation so that the FDE's rows are 767 // valid. 768 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 769 770 // If the function is empty and the object file uses .subsections_via_symbols, 771 // then we need to emit *something* to the function body to prevent the 772 // labels from collapsing together. Just emit a noop. 773 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 774 MCInst Noop; 775 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 776 if (Noop.getOpcode()) { 777 OutStreamer.AddComment("avoids zero-length function"); 778 OutStreamer.EmitInstruction(Noop); 779 } else // Target not mc-ized yet. 780 OutStreamer.EmitRawText(StringRef("\tnop\n")); 781 } 782 783 const Function *F = MF->getFunction(); 784 for (Function::const_iterator i = F->begin(), e = F->end(); i != e; ++i) { 785 const BasicBlock *BB = i; 786 if (!BB->hasAddressTaken()) 787 continue; 788 MCSymbol *Sym = GetBlockAddressSymbol(BB); 789 if (Sym->isDefined()) 790 continue; 791 OutStreamer.AddComment("Address of block that was removed by CodeGen"); 792 OutStreamer.EmitLabel(Sym); 793 } 794 795 // Emit target-specific gunk after the function body. 796 EmitFunctionBodyEnd(); 797 798 // If the target wants a .size directive for the size of the function, emit 799 // it. 800 if (MAI->hasDotTypeDotSizeDirective()) { 801 // Create a symbol for the end of function, so we can get the size as 802 // difference between the function label and the temp label. 803 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 804 OutStreamer.EmitLabel(FnEndLabel); 805 806 const MCExpr *SizeExp = 807 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 808 MCSymbolRefExpr::Create(CurrentFnSymForSize, 809 OutContext), 810 OutContext); 811 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 812 } 813 814 // Emit post-function debug information. 815 if (DD) { 816 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 817 DD->endFunction(MF); 818 } 819 if (DE) { 820 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 821 DE->EndFunction(); 822 } 823 MMI->EndFunction(); 824 825 // Print out jump tables referenced by the function. 826 EmitJumpTableInfo(); 827 828 OutStreamer.AddBlankLine(); 829} 830 831/// EmitDwarfRegOp - Emit dwarf register operation. 832void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc, 833 bool Indirect) const { 834 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 835 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false); 836 837 for (MCSuperRegIterator SR(MLoc.getReg(), TRI); SR.isValid() && Reg < 0; 838 ++SR) { 839 Reg = TRI->getDwarfRegNum(*SR, false); 840 // FIXME: Get the bit range this register uses of the superregister 841 // so that we can produce a DW_OP_bit_piece 842 } 843 844 // FIXME: Handle cases like a super register being encoded as 845 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33 846 847 // FIXME: We have no reasonable way of handling errors in here. The 848 // caller might be in the middle of an dwarf expression. We should 849 // probably assert that Reg >= 0 once debug info generation is more mature. 850 851 if (MLoc.isIndirect() || Indirect) { 852 if (Reg < 32) { 853 OutStreamer.AddComment( 854 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg)); 855 EmitInt8(dwarf::DW_OP_breg0 + Reg); 856 } else { 857 OutStreamer.AddComment("DW_OP_bregx"); 858 EmitInt8(dwarf::DW_OP_bregx); 859 OutStreamer.AddComment(Twine(Reg)); 860 EmitULEB128(Reg); 861 } 862 EmitSLEB128(!MLoc.isIndirect() ? 0 : MLoc.getOffset()); 863 if (MLoc.isIndirect() && Indirect) 864 EmitInt8(dwarf::DW_OP_deref); 865 } else { 866 if (Reg < 32) { 867 OutStreamer.AddComment( 868 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg)); 869 EmitInt8(dwarf::DW_OP_reg0 + Reg); 870 } else { 871 OutStreamer.AddComment("DW_OP_regx"); 872 EmitInt8(dwarf::DW_OP_regx); 873 OutStreamer.AddComment(Twine(Reg)); 874 EmitULEB128(Reg); 875 } 876 } 877 878 // FIXME: Produce a DW_OP_bit_piece if we used a superregister 879} 880 881bool AsmPrinter::doFinalization(Module &M) { 882 // Emit global variables. 883 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 884 I != E; ++I) 885 EmitGlobalVariable(I); 886 887 // Emit visibility info for declarations 888 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 889 const Function &F = *I; 890 if (!F.isDeclaration()) 891 continue; 892 GlobalValue::VisibilityTypes V = F.getVisibility(); 893 if (V == GlobalValue::DefaultVisibility) 894 continue; 895 896 MCSymbol *Name = getSymbol(&F); 897 EmitVisibility(Name, V, false); 898 } 899 900 // Emit module flags. 901 SmallVector<Module::ModuleFlagEntry, 8> ModuleFlags; 902 M.getModuleFlagsMetadata(ModuleFlags); 903 if (!ModuleFlags.empty()) 904 getObjFileLowering().emitModuleFlags(OutStreamer, ModuleFlags, Mang, TM); 905 906 // Make sure we wrote out everything we need. 907 OutStreamer.Flush(); 908 909 // Finalize debug and EH information. 910 if (DE) { 911 { 912 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 913 DE->EndModule(); 914 } 915 delete DE; DE = 0; 916 } 917 if (DD) { 918 { 919 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 920 DD->endModule(); 921 } 922 delete DD; DD = 0; 923 } 924 925 // If the target wants to know about weak references, print them all. 926 if (MAI->getWeakRefDirective()) { 927 // FIXME: This is not lazy, it would be nice to only print weak references 928 // to stuff that is actually used. Note that doing so would require targets 929 // to notice uses in operands (due to constant exprs etc). This should 930 // happen with the MC stuff eventually. 931 932 // Print out module-level global variables here. 933 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 934 I != E; ++I) { 935 if (!I->hasExternalWeakLinkage()) continue; 936 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference); 937 } 938 939 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 940 if (!I->hasExternalWeakLinkage()) continue; 941 OutStreamer.EmitSymbolAttribute(getSymbol(I), MCSA_WeakReference); 942 } 943 } 944 945 if (MAI->hasSetDirective()) { 946 OutStreamer.AddBlankLine(); 947 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 948 I != E; ++I) { 949 MCSymbol *Name = getSymbol(I); 950 951 const GlobalValue *GV = I->getAliasedGlobal(); 952 if (GV->isDeclaration()) { 953 report_fatal_error(Name->getName() + 954 ": Target doesn't support aliases to declarations"); 955 } 956 957 MCSymbol *Target = getSymbol(GV); 958 959 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 960 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 961 else if (I->hasWeakLinkage() || I->hasLinkOnceLinkage()) 962 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 963 else 964 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 965 966 EmitVisibility(Name, I->getVisibility()); 967 968 // Emit the directives as assignments aka .set: 969 OutStreamer.EmitAssignment(Name, 970 MCSymbolRefExpr::Create(Target, OutContext)); 971 } 972 } 973 974 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 975 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 976 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 977 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 978 MP->finishAssembly(*this); 979 980 // Emit llvm.ident metadata in an '.ident' directive. 981 EmitModuleIdents(M); 982 983 // If we don't have any trampolines, then we don't require stack memory 984 // to be executable. Some targets have a directive to declare this. 985 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 986 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 987 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 988 OutStreamer.SwitchSection(S); 989 990 // Allow the target to emit any magic that it wants at the end of the file, 991 // after everything else has gone out. 992 EmitEndOfAsmFile(M); 993 994 delete Mang; Mang = 0; 995 MMI = 0; 996 997 OutStreamer.Finish(); 998 OutStreamer.reset(); 999 1000 return false; 1001} 1002 1003void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 1004 this->MF = &MF; 1005 // Get the function symbol. 1006 CurrentFnSym = getSymbol(MF.getFunction()); 1007 CurrentFnSymForSize = CurrentFnSym; 1008 1009 if (isVerbose()) 1010 LI = &getAnalysis<MachineLoopInfo>(); 1011} 1012 1013namespace { 1014 // SectionCPs - Keep track the alignment, constpool entries per Section. 1015 struct SectionCPs { 1016 const MCSection *S; 1017 unsigned Alignment; 1018 SmallVector<unsigned, 4> CPEs; 1019 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 1020 }; 1021} 1022 1023/// EmitConstantPool - Print to the current output stream assembly 1024/// representations of the constants in the constant pool MCP. This is 1025/// used to print out constants which have been "spilled to memory" by 1026/// the code generator. 1027/// 1028void AsmPrinter::EmitConstantPool() { 1029 const MachineConstantPool *MCP = MF->getConstantPool(); 1030 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 1031 if (CP.empty()) return; 1032 1033 // Calculate sections for constant pool entries. We collect entries to go into 1034 // the same section together to reduce amount of section switch statements. 1035 SmallVector<SectionCPs, 4> CPSections; 1036 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 1037 const MachineConstantPoolEntry &CPE = CP[i]; 1038 unsigned Align = CPE.getAlignment(); 1039 1040 SectionKind Kind; 1041 switch (CPE.getRelocationInfo()) { 1042 default: llvm_unreachable("Unknown section kind"); 1043 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 1044 case 1: 1045 Kind = SectionKind::getReadOnlyWithRelLocal(); 1046 break; 1047 case 0: 1048 switch (TM.getDataLayout()->getTypeAllocSize(CPE.getType())) { 1049 case 4: Kind = SectionKind::getMergeableConst4(); break; 1050 case 8: Kind = SectionKind::getMergeableConst8(); break; 1051 case 16: Kind = SectionKind::getMergeableConst16();break; 1052 default: Kind = SectionKind::getMergeableConst(); break; 1053 } 1054 } 1055 1056 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 1057 1058 // The number of sections are small, just do a linear search from the 1059 // last section to the first. 1060 bool Found = false; 1061 unsigned SecIdx = CPSections.size(); 1062 while (SecIdx != 0) { 1063 if (CPSections[--SecIdx].S == S) { 1064 Found = true; 1065 break; 1066 } 1067 } 1068 if (!Found) { 1069 SecIdx = CPSections.size(); 1070 CPSections.push_back(SectionCPs(S, Align)); 1071 } 1072 1073 if (Align > CPSections[SecIdx].Alignment) 1074 CPSections[SecIdx].Alignment = Align; 1075 CPSections[SecIdx].CPEs.push_back(i); 1076 } 1077 1078 // Now print stuff into the calculated sections. 1079 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 1080 OutStreamer.SwitchSection(CPSections[i].S); 1081 EmitAlignment(Log2_32(CPSections[i].Alignment)); 1082 1083 unsigned Offset = 0; 1084 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 1085 unsigned CPI = CPSections[i].CPEs[j]; 1086 MachineConstantPoolEntry CPE = CP[CPI]; 1087 1088 // Emit inter-object padding for alignment. 1089 unsigned AlignMask = CPE.getAlignment() - 1; 1090 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 1091 OutStreamer.EmitZeros(NewOffset - Offset); 1092 1093 Type *Ty = CPE.getType(); 1094 Offset = NewOffset + TM.getDataLayout()->getTypeAllocSize(Ty); 1095 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 1096 1097 if (CPE.isMachineConstantPoolEntry()) 1098 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 1099 else 1100 EmitGlobalConstant(CPE.Val.ConstVal); 1101 } 1102 } 1103} 1104 1105/// EmitJumpTableInfo - Print assembly representations of the jump tables used 1106/// by the current function to the current output stream. 1107/// 1108void AsmPrinter::EmitJumpTableInfo() { 1109 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1110 if (MJTI == 0) return; 1111 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1112 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1113 if (JT.empty()) return; 1114 1115 // Pick the directive to use to print the jump table entries, and switch to 1116 // the appropriate section. 1117 const Function *F = MF->getFunction(); 1118 bool JTInDiffSection = false; 1119 if (// In PIC mode, we need to emit the jump table to the same section as the 1120 // function body itself, otherwise the label differences won't make sense. 1121 // FIXME: Need a better predicate for this: what about custom entries? 1122 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1123 // We should also do if the section name is NULL or function is declared 1124 // in discardable section 1125 // FIXME: this isn't the right predicate, should be based on the MCSection 1126 // for the function. 1127 F->isWeakForLinker()) { 1128 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 1129 } else { 1130 // Otherwise, drop it in the readonly section. 1131 const MCSection *ReadOnlySection = 1132 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1133 OutStreamer.SwitchSection(ReadOnlySection); 1134 JTInDiffSection = true; 1135 } 1136 1137 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getDataLayout()))); 1138 1139 // Jump tables in code sections are marked with a data_region directive 1140 // where that's supported. 1141 if (!JTInDiffSection) 1142 OutStreamer.EmitDataRegion(MCDR_DataRegionJT32); 1143 1144 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1145 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1146 1147 // If this jump table was deleted, ignore it. 1148 if (JTBBs.empty()) continue; 1149 1150 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1151 // .set directive for each unique entry. This reduces the number of 1152 // relocations the assembler will generate for the jump table. 1153 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1154 MAI->hasSetDirective()) { 1155 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1156 const TargetLowering *TLI = TM.getTargetLowering(); 1157 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1158 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1159 const MachineBasicBlock *MBB = JTBBs[ii]; 1160 if (!EmittedSets.insert(MBB)) continue; 1161 1162 // .set LJTSet, LBB32-base 1163 const MCExpr *LHS = 1164 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1165 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1166 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1167 } 1168 } 1169 1170 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1171 // before each jump table. The first label is never referenced, but tells 1172 // the assembler and linker the extents of the jump table object. The 1173 // second label is actually referenced by the code. 1174 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1175 // FIXME: This doesn't have to have any specific name, just any randomly 1176 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1177 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1178 1179 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1180 1181 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1182 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1183 } 1184 if (!JTInDiffSection) 1185 OutStreamer.EmitDataRegion(MCDR_DataRegionEnd); 1186} 1187 1188/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1189/// current stream. 1190void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1191 const MachineBasicBlock *MBB, 1192 unsigned UID) const { 1193 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1194 const MCExpr *Value = 0; 1195 switch (MJTI->getEntryKind()) { 1196 case MachineJumpTableInfo::EK_Inline: 1197 llvm_unreachable("Cannot emit EK_Inline jump table entry"); 1198 case MachineJumpTableInfo::EK_Custom32: 1199 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1200 OutContext); 1201 break; 1202 case MachineJumpTableInfo::EK_BlockAddress: 1203 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1204 // .word LBB123 1205 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1206 break; 1207 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1208 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1209 // with a relocation as gp-relative, e.g.: 1210 // .gprel32 LBB123 1211 MCSymbol *MBBSym = MBB->getSymbol(); 1212 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1213 return; 1214 } 1215 1216 case MachineJumpTableInfo::EK_GPRel64BlockAddress: { 1217 // EK_GPRel64BlockAddress - Each entry is an address of block, encoded 1218 // with a relocation as gp-relative, e.g.: 1219 // .gpdword LBB123 1220 MCSymbol *MBBSym = MBB->getSymbol(); 1221 OutStreamer.EmitGPRel64Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1222 return; 1223 } 1224 1225 case MachineJumpTableInfo::EK_LabelDifference32: { 1226 // EK_LabelDifference32 - Each entry is the address of the block minus 1227 // the address of the jump table. This is used for PIC jump tables where 1228 // gprel32 is not supported. e.g.: 1229 // .word LBB123 - LJTI1_2 1230 // If the .set directive is supported, this is emitted as: 1231 // .set L4_5_set_123, LBB123 - LJTI1_2 1232 // .word L4_5_set_123 1233 1234 // If we have emitted set directives for the jump table entries, print 1235 // them rather than the entries themselves. If we're emitting PIC, then 1236 // emit the table entries as differences between two text section labels. 1237 if (MAI->hasSetDirective()) { 1238 // If we used .set, reference the .set's symbol. 1239 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1240 OutContext); 1241 break; 1242 } 1243 // Otherwise, use the difference as the jump table entry. 1244 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1245 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1246 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1247 break; 1248 } 1249 } 1250 1251 assert(Value && "Unknown entry kind!"); 1252 1253 unsigned EntrySize = MJTI->getEntrySize(*TM.getDataLayout()); 1254 OutStreamer.EmitValue(Value, EntrySize); 1255} 1256 1257 1258/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1259/// special global used by LLVM. If so, emit it and return true, otherwise 1260/// do nothing and return false. 1261bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1262 if (GV->getName() == "llvm.used") { 1263 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1264 EmitLLVMUsedList(cast<ConstantArray>(GV->getInitializer())); 1265 return true; 1266 } 1267 1268 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1269 if (GV->getSection() == "llvm.metadata" || 1270 GV->hasAvailableExternallyLinkage()) 1271 return true; 1272 1273 if (!GV->hasAppendingLinkage()) return false; 1274 1275 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1276 1277 if (GV->getName() == "llvm.global_ctors") { 1278 EmitXXStructorList(GV->getInitializer(), /* isCtor */ true); 1279 1280 if (TM.getRelocationModel() == Reloc::Static && 1281 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1282 StringRef Sym(".constructors_used"); 1283 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1284 MCSA_Reference); 1285 } 1286 return true; 1287 } 1288 1289 if (GV->getName() == "llvm.global_dtors") { 1290 EmitXXStructorList(GV->getInitializer(), /* isCtor */ false); 1291 1292 if (TM.getRelocationModel() == Reloc::Static && 1293 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1294 StringRef Sym(".destructors_used"); 1295 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1296 MCSA_Reference); 1297 } 1298 return true; 1299 } 1300 1301 return false; 1302} 1303 1304/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1305/// global in the specified llvm.used list for which emitUsedDirectiveFor 1306/// is true, as being used with this directive. 1307void AsmPrinter::EmitLLVMUsedList(const ConstantArray *InitList) { 1308 // Should be an array of 'i8*'. 1309 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1310 const GlobalValue *GV = 1311 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1312 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1313 OutStreamer.EmitSymbolAttribute(getSymbol(GV), MCSA_NoDeadStrip); 1314 } 1315} 1316 1317/// EmitXXStructorList - Emit the ctor or dtor list taking into account the init 1318/// priority. 1319void AsmPrinter::EmitXXStructorList(const Constant *List, bool isCtor) { 1320 // Should be an array of '{ int, void ()* }' structs. The first value is the 1321 // init priority. 1322 if (!isa<ConstantArray>(List)) return; 1323 1324 // Sanity check the structors list. 1325 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1326 if (!InitList) return; // Not an array! 1327 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType()); 1328 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs! 1329 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) || 1330 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr). 1331 1332 // Gather the structors in a form that's convenient for sorting by priority. 1333 typedef std::pair<unsigned, Constant *> Structor; 1334 SmallVector<Structor, 8> Structors; 1335 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1336 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i)); 1337 if (!CS) continue; // Malformed. 1338 if (CS->getOperand(1)->isNullValue()) 1339 break; // Found a null terminator, skip the rest. 1340 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0)); 1341 if (!Priority) continue; // Malformed. 1342 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535), 1343 CS->getOperand(1))); 1344 } 1345 1346 // Emit the function pointers in the target-specific order 1347 const DataLayout *DL = TM.getDataLayout(); 1348 unsigned Align = Log2_32(DL->getPointerPrefAlignment()); 1349 std::stable_sort(Structors.begin(), Structors.end(), less_first()); 1350 for (unsigned i = 0, e = Structors.size(); i != e; ++i) { 1351 const MCSection *OutputSection = 1352 (isCtor ? 1353 getObjFileLowering().getStaticCtorSection(Structors[i].first) : 1354 getObjFileLowering().getStaticDtorSection(Structors[i].first)); 1355 OutStreamer.SwitchSection(OutputSection); 1356 if (OutStreamer.getCurrentSection() != OutStreamer.getPreviousSection()) 1357 EmitAlignment(Align); 1358 EmitXXStructor(Structors[i].second); 1359 } 1360} 1361 1362void AsmPrinter::EmitModuleIdents(Module &M) { 1363 if (!MAI->hasIdentDirective()) 1364 return; 1365 1366 if (const NamedMDNode *NMD = M.getNamedMetadata("llvm.ident")) { 1367 for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) { 1368 const MDNode *N = NMD->getOperand(i); 1369 assert(N->getNumOperands() == 1 && 1370 "llvm.ident metadata entry can have only one operand"); 1371 const MDString *S = cast<MDString>(N->getOperand(0)); 1372 OutStreamer.EmitIdent(S->getString()); 1373 } 1374 } 1375} 1376 1377//===--------------------------------------------------------------------===// 1378// Emission and print routines 1379// 1380 1381/// EmitInt8 - Emit a byte directive and value. 1382/// 1383void AsmPrinter::EmitInt8(int Value) const { 1384 OutStreamer.EmitIntValue(Value, 1); 1385} 1386 1387/// EmitInt16 - Emit a short directive and value. 1388/// 1389void AsmPrinter::EmitInt16(int Value) const { 1390 OutStreamer.EmitIntValue(Value, 2); 1391} 1392 1393/// EmitInt32 - Emit a long directive and value. 1394/// 1395void AsmPrinter::EmitInt32(int Value) const { 1396 OutStreamer.EmitIntValue(Value, 4); 1397} 1398 1399/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1400/// in bytes of the directive is specified by Size and Hi/Lo specify the 1401/// labels. This implicitly uses .set if it is available. 1402void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1403 unsigned Size) const { 1404 // Get the Hi-Lo expression. 1405 const MCExpr *Diff = 1406 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1407 MCSymbolRefExpr::Create(Lo, OutContext), 1408 OutContext); 1409 1410 if (!MAI->hasSetDirective()) { 1411 OutStreamer.EmitValue(Diff, Size); 1412 return; 1413 } 1414 1415 // Otherwise, emit with .set (aka assignment). 1416 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1417 OutStreamer.EmitAssignment(SetLabel, Diff); 1418 OutStreamer.EmitSymbolValue(SetLabel, Size); 1419} 1420 1421/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1422/// where the size in bytes of the directive is specified by Size and Hi/Lo 1423/// specify the labels. This implicitly uses .set if it is available. 1424void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1425 const MCSymbol *Lo, unsigned Size) 1426 const { 1427 1428 // Emit Hi+Offset - Lo 1429 // Get the Hi+Offset expression. 1430 const MCExpr *Plus = 1431 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1432 MCConstantExpr::Create(Offset, OutContext), 1433 OutContext); 1434 1435 // Get the Hi+Offset-Lo expression. 1436 const MCExpr *Diff = 1437 MCBinaryExpr::CreateSub(Plus, 1438 MCSymbolRefExpr::Create(Lo, OutContext), 1439 OutContext); 1440 1441 if (!MAI->hasSetDirective()) 1442 OutStreamer.EmitValue(Diff, Size); 1443 else { 1444 // Otherwise, emit with .set (aka assignment). 1445 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1446 OutStreamer.EmitAssignment(SetLabel, Diff); 1447 OutStreamer.EmitSymbolValue(SetLabel, Size); 1448 } 1449} 1450 1451/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1452/// where the size in bytes of the directive is specified by Size and Label 1453/// specifies the label. This implicitly uses .set if it is available. 1454void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1455 unsigned Size, bool IsSectionRelative) 1456 const { 1457 if (MAI->needsDwarfSectionOffsetDirective() && IsSectionRelative) { 1458 OutStreamer.EmitCOFFSecRel32(Label); 1459 return; 1460 } 1461 1462 // Emit Label+Offset (or just Label if Offset is zero) 1463 const MCExpr *Expr = MCSymbolRefExpr::Create(Label, OutContext); 1464 if (Offset) 1465 Expr = MCBinaryExpr::CreateAdd(Expr, 1466 MCConstantExpr::Create(Offset, OutContext), 1467 OutContext); 1468 1469 OutStreamer.EmitValue(Expr, Size); 1470} 1471 1472 1473//===----------------------------------------------------------------------===// 1474 1475// EmitAlignment - Emit an alignment directive to the specified power of 1476// two boundary. For example, if you pass in 3 here, you will get an 8 1477// byte alignment. If a global value is specified, and if that global has 1478// an explicit alignment requested, it will override the alignment request 1479// if required for correctness. 1480// 1481void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1482 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getDataLayout(), NumBits); 1483 1484 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1485 1486 if (getCurrentSection()->getKind().isText()) 1487 OutStreamer.EmitCodeAlignment(1 << NumBits); 1488 else 1489 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1490} 1491 1492//===----------------------------------------------------------------------===// 1493// Constant emission. 1494//===----------------------------------------------------------------------===// 1495 1496/// lowerConstant - Lower the specified LLVM Constant to an MCExpr. 1497/// 1498static const MCExpr *lowerConstant(const Constant *CV, AsmPrinter &AP) { 1499 MCContext &Ctx = AP.OutContext; 1500 1501 if (CV->isNullValue() || isa<UndefValue>(CV)) 1502 return MCConstantExpr::Create(0, Ctx); 1503 1504 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1505 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1506 1507 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1508 return MCSymbolRefExpr::Create(AP.getSymbol(GV), Ctx); 1509 1510 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1511 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1512 1513 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1514 if (CE == 0) { 1515 llvm_unreachable("Unknown constant value to lower!"); 1516 } 1517 1518 switch (CE->getOpcode()) { 1519 default: 1520 // If the code isn't optimized, there may be outstanding folding 1521 // opportunities. Attempt to fold the expression using DataLayout as a 1522 // last resort before giving up. 1523 if (Constant *C = 1524 ConstantFoldConstantExpression(CE, AP.TM.getDataLayout())) 1525 if (C != CE) 1526 return lowerConstant(C, AP); 1527 1528 // Otherwise report the problem to the user. 1529 { 1530 std::string S; 1531 raw_string_ostream OS(S); 1532 OS << "Unsupported expression in static initializer: "; 1533 WriteAsOperand(OS, CE, /*PrintType=*/false, 1534 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1535 report_fatal_error(OS.str()); 1536 } 1537 case Instruction::GetElementPtr: { 1538 const DataLayout &DL = *AP.TM.getDataLayout(); 1539 // Generate a symbolic expression for the byte address 1540 APInt OffsetAI(DL.getPointerTypeSizeInBits(CE->getType()), 0); 1541 cast<GEPOperator>(CE)->accumulateConstantOffset(DL, OffsetAI); 1542 1543 const MCExpr *Base = lowerConstant(CE->getOperand(0), AP); 1544 if (!OffsetAI) 1545 return Base; 1546 1547 int64_t Offset = OffsetAI.getSExtValue(); 1548 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1549 Ctx); 1550 } 1551 1552 case Instruction::Trunc: 1553 // We emit the value and depend on the assembler to truncate the generated 1554 // expression properly. This is important for differences between 1555 // blockaddress labels. Since the two labels are in the same function, it 1556 // is reasonable to treat their delta as a 32-bit value. 1557 // FALL THROUGH. 1558 case Instruction::BitCast: 1559 return lowerConstant(CE->getOperand(0), AP); 1560 1561 case Instruction::IntToPtr: { 1562 const DataLayout &DL = *AP.TM.getDataLayout(); 1563 // Handle casts to pointers by changing them into casts to the appropriate 1564 // integer type. This promotes constant folding and simplifies this code. 1565 Constant *Op = CE->getOperand(0); 1566 Op = ConstantExpr::getIntegerCast(Op, DL.getIntPtrType(CV->getType()), 1567 false/*ZExt*/); 1568 return lowerConstant(Op, AP); 1569 } 1570 1571 case Instruction::PtrToInt: { 1572 const DataLayout &DL = *AP.TM.getDataLayout(); 1573 // Support only foldable casts to/from pointers that can be eliminated by 1574 // changing the pointer to the appropriately sized integer type. 1575 Constant *Op = CE->getOperand(0); 1576 Type *Ty = CE->getType(); 1577 1578 const MCExpr *OpExpr = lowerConstant(Op, AP); 1579 1580 // We can emit the pointer value into this slot if the slot is an 1581 // integer slot equal to the size of the pointer. 1582 if (DL.getTypeAllocSize(Ty) == DL.getTypeAllocSize(Op->getType())) 1583 return OpExpr; 1584 1585 // Otherwise the pointer is smaller than the resultant integer, mask off 1586 // the high bits so we are sure to get a proper truncation if the input is 1587 // a constant expr. 1588 unsigned InBits = DL.getTypeAllocSizeInBits(Op->getType()); 1589 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1590 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1591 } 1592 1593 // The MC library also has a right-shift operator, but it isn't consistently 1594 // signed or unsigned between different targets. 1595 case Instruction::Add: 1596 case Instruction::Sub: 1597 case Instruction::Mul: 1598 case Instruction::SDiv: 1599 case Instruction::SRem: 1600 case Instruction::Shl: 1601 case Instruction::And: 1602 case Instruction::Or: 1603 case Instruction::Xor: { 1604 const MCExpr *LHS = lowerConstant(CE->getOperand(0), AP); 1605 const MCExpr *RHS = lowerConstant(CE->getOperand(1), AP); 1606 switch (CE->getOpcode()) { 1607 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1608 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1609 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1610 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1611 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1612 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1613 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1614 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1615 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1616 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1617 } 1618 } 1619 } 1620} 1621 1622static void emitGlobalConstantImpl(const Constant *C, AsmPrinter &AP); 1623 1624/// isRepeatedByteSequence - Determine whether the given value is 1625/// composed of a repeated sequence of identical bytes and return the 1626/// byte value. If it is not a repeated sequence, return -1. 1627static int isRepeatedByteSequence(const ConstantDataSequential *V) { 1628 StringRef Data = V->getRawDataValues(); 1629 assert(!Data.empty() && "Empty aggregates should be CAZ node"); 1630 char C = Data[0]; 1631 for (unsigned i = 1, e = Data.size(); i != e; ++i) 1632 if (Data[i] != C) return -1; 1633 return static_cast<uint8_t>(C); // Ensure 255 is not returned as -1. 1634} 1635 1636 1637/// isRepeatedByteSequence - Determine whether the given value is 1638/// composed of a repeated sequence of identical bytes and return the 1639/// byte value. If it is not a repeated sequence, return -1. 1640static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) { 1641 1642 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { 1643 if (CI->getBitWidth() > 64) return -1; 1644 1645 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(V->getType()); 1646 uint64_t Value = CI->getZExtValue(); 1647 1648 // Make sure the constant is at least 8 bits long and has a power 1649 // of 2 bit width. This guarantees the constant bit width is 1650 // always a multiple of 8 bits, avoiding issues with padding out 1651 // to Size and other such corner cases. 1652 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1; 1653 1654 uint8_t Byte = static_cast<uint8_t>(Value); 1655 1656 for (unsigned i = 1; i < Size; ++i) { 1657 Value >>= 8; 1658 if (static_cast<uint8_t>(Value) != Byte) return -1; 1659 } 1660 return Byte; 1661 } 1662 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) { 1663 // Make sure all array elements are sequences of the same repeated 1664 // byte. 1665 assert(CA->getNumOperands() != 0 && "Should be a CAZ"); 1666 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM); 1667 if (Byte == -1) return -1; 1668 1669 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) { 1670 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM); 1671 if (ThisByte == -1) return -1; 1672 if (Byte != ThisByte) return -1; 1673 } 1674 return Byte; 1675 } 1676 1677 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(V)) 1678 return isRepeatedByteSequence(CDS); 1679 1680 return -1; 1681} 1682 1683static void emitGlobalConstantDataSequential(const ConstantDataSequential *CDS, 1684 AsmPrinter &AP){ 1685 1686 // See if we can aggregate this into a .fill, if so, emit it as such. 1687 int Value = isRepeatedByteSequence(CDS, AP.TM); 1688 if (Value != -1) { 1689 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CDS->getType()); 1690 // Don't emit a 1-byte object as a .fill. 1691 if (Bytes > 1) 1692 return AP.OutStreamer.EmitFill(Bytes, Value); 1693 } 1694 1695 // If this can be emitted with .ascii/.asciz, emit it as such. 1696 if (CDS->isString()) 1697 return AP.OutStreamer.EmitBytes(CDS->getAsString()); 1698 1699 // Otherwise, emit the values in successive locations. 1700 unsigned ElementByteSize = CDS->getElementByteSize(); 1701 if (isa<IntegerType>(CDS->getElementType())) { 1702 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1703 if (AP.isVerbose()) 1704 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1705 CDS->getElementAsInteger(i)); 1706 AP.OutStreamer.EmitIntValue(CDS->getElementAsInteger(i), 1707 ElementByteSize); 1708 } 1709 } else if (ElementByteSize == 4) { 1710 // FP Constants are printed as integer constants to avoid losing 1711 // precision. 1712 assert(CDS->getElementType()->isFloatTy()); 1713 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1714 union { 1715 float F; 1716 uint32_t I; 1717 }; 1718 1719 F = CDS->getElementAsFloat(i); 1720 if (AP.isVerbose()) 1721 AP.OutStreamer.GetCommentOS() << "float " << F << '\n'; 1722 AP.OutStreamer.EmitIntValue(I, 4); 1723 } 1724 } else { 1725 assert(CDS->getElementType()->isDoubleTy()); 1726 for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) { 1727 union { 1728 double F; 1729 uint64_t I; 1730 }; 1731 1732 F = CDS->getElementAsDouble(i); 1733 if (AP.isVerbose()) 1734 AP.OutStreamer.GetCommentOS() << "double " << F << '\n'; 1735 AP.OutStreamer.EmitIntValue(I, 8); 1736 } 1737 } 1738 1739 const DataLayout &DL = *AP.TM.getDataLayout(); 1740 unsigned Size = DL.getTypeAllocSize(CDS->getType()); 1741 unsigned EmittedSize = DL.getTypeAllocSize(CDS->getType()->getElementType()) * 1742 CDS->getNumElements(); 1743 if (unsigned Padding = Size - EmittedSize) 1744 AP.OutStreamer.EmitZeros(Padding); 1745 1746} 1747 1748static void emitGlobalConstantArray(const ConstantArray *CA, AsmPrinter &AP) { 1749 // See if we can aggregate some values. Make sure it can be 1750 // represented as a series of bytes of the constant value. 1751 int Value = isRepeatedByteSequence(CA, AP.TM); 1752 1753 if (Value != -1) { 1754 uint64_t Bytes = AP.TM.getDataLayout()->getTypeAllocSize(CA->getType()); 1755 AP.OutStreamer.EmitFill(Bytes, Value); 1756 } 1757 else { 1758 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1759 emitGlobalConstantImpl(CA->getOperand(i), AP); 1760 } 1761} 1762 1763static void emitGlobalConstantVector(const ConstantVector *CV, AsmPrinter &AP) { 1764 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1765 emitGlobalConstantImpl(CV->getOperand(i), AP); 1766 1767 const DataLayout &DL = *AP.TM.getDataLayout(); 1768 unsigned Size = DL.getTypeAllocSize(CV->getType()); 1769 unsigned EmittedSize = DL.getTypeAllocSize(CV->getType()->getElementType()) * 1770 CV->getType()->getNumElements(); 1771 if (unsigned Padding = Size - EmittedSize) 1772 AP.OutStreamer.EmitZeros(Padding); 1773} 1774 1775static void emitGlobalConstantStruct(const ConstantStruct *CS, AsmPrinter &AP) { 1776 // Print the fields in successive locations. Pad to align if needed! 1777 const DataLayout *DL = AP.TM.getDataLayout(); 1778 unsigned Size = DL->getTypeAllocSize(CS->getType()); 1779 const StructLayout *Layout = DL->getStructLayout(CS->getType()); 1780 uint64_t SizeSoFar = 0; 1781 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1782 const Constant *Field = CS->getOperand(i); 1783 1784 // Check if padding is needed and insert one or more 0s. 1785 uint64_t FieldSize = DL->getTypeAllocSize(Field->getType()); 1786 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1787 - Layout->getElementOffset(i)) - FieldSize; 1788 SizeSoFar += FieldSize + PadSize; 1789 1790 // Now print the actual field value. 1791 emitGlobalConstantImpl(Field, AP); 1792 1793 // Insert padding - this may include padding to increase the size of the 1794 // current field up to the ABI size (if the struct is not packed) as well 1795 // as padding to ensure that the next field starts at the right offset. 1796 AP.OutStreamer.EmitZeros(PadSize); 1797 } 1798 assert(SizeSoFar == Layout->getSizeInBytes() && 1799 "Layout of constant struct may be incorrect!"); 1800} 1801 1802static void emitGlobalConstantFP(const ConstantFP *CFP, AsmPrinter &AP) { 1803 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1804 1805 // First print a comment with what we think the original floating-point value 1806 // should have been. 1807 if (AP.isVerbose()) { 1808 SmallString<8> StrVal; 1809 CFP->getValueAPF().toString(StrVal); 1810 1811 CFP->getType()->print(AP.OutStreamer.GetCommentOS()); 1812 AP.OutStreamer.GetCommentOS() << ' ' << StrVal << '\n'; 1813 } 1814 1815 // Now iterate through the APInt chunks, emitting them in endian-correct 1816 // order, possibly with a smaller chunk at beginning/end (e.g. for x87 80-bit 1817 // floats). 1818 unsigned NumBytes = API.getBitWidth() / 8; 1819 unsigned TrailingBytes = NumBytes % sizeof(uint64_t); 1820 const uint64_t *p = API.getRawData(); 1821 1822 // PPC's long double has odd notions of endianness compared to how LLVM 1823 // handles it: p[0] goes first for *big* endian on PPC. 1824 if (AP.TM.getDataLayout()->isBigEndian() != CFP->getType()->isPPC_FP128Ty()) { 1825 int Chunk = API.getNumWords() - 1; 1826 1827 if (TrailingBytes) 1828 AP.OutStreamer.EmitIntValue(p[Chunk--], TrailingBytes); 1829 1830 for (; Chunk >= 0; --Chunk) 1831 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t)); 1832 } else { 1833 unsigned Chunk; 1834 for (Chunk = 0; Chunk < NumBytes / sizeof(uint64_t); ++Chunk) 1835 AP.OutStreamer.EmitIntValue(p[Chunk], sizeof(uint64_t)); 1836 1837 if (TrailingBytes) 1838 AP.OutStreamer.EmitIntValue(p[Chunk], TrailingBytes); 1839 } 1840 1841 // Emit the tail padding for the long double. 1842 const DataLayout &DL = *AP.TM.getDataLayout(); 1843 AP.OutStreamer.EmitZeros(DL.getTypeAllocSize(CFP->getType()) - 1844 DL.getTypeStoreSize(CFP->getType())); 1845} 1846 1847static void emitGlobalConstantLargeInt(const ConstantInt *CI, AsmPrinter &AP) { 1848 const DataLayout *DL = AP.TM.getDataLayout(); 1849 unsigned BitWidth = CI->getBitWidth(); 1850 1851 // Copy the value as we may massage the layout for constants whose bit width 1852 // is not a multiple of 64-bits. 1853 APInt Realigned(CI->getValue()); 1854 uint64_t ExtraBits = 0; 1855 unsigned ExtraBitsSize = BitWidth & 63; 1856 1857 if (ExtraBitsSize) { 1858 // The bit width of the data is not a multiple of 64-bits. 1859 // The extra bits are expected to be at the end of the chunk of the memory. 1860 // Little endian: 1861 // * Nothing to be done, just record the extra bits to emit. 1862 // Big endian: 1863 // * Record the extra bits to emit. 1864 // * Realign the raw data to emit the chunks of 64-bits. 1865 if (DL->isBigEndian()) { 1866 // Basically the structure of the raw data is a chunk of 64-bits cells: 1867 // 0 1 BitWidth / 64 1868 // [chunk1][chunk2] ... [chunkN]. 1869 // The most significant chunk is chunkN and it should be emitted first. 1870 // However, due to the alignment issue chunkN contains useless bits. 1871 // Realign the chunks so that they contain only useless information: 1872 // ExtraBits 0 1 (BitWidth / 64) - 1 1873 // chu[nk1 chu][nk2 chu] ... [nkN-1 chunkN] 1874 ExtraBits = Realigned.getRawData()[0] & 1875 (((uint64_t)-1) >> (64 - ExtraBitsSize)); 1876 Realigned = Realigned.lshr(ExtraBitsSize); 1877 } else 1878 ExtraBits = Realigned.getRawData()[BitWidth / 64]; 1879 } 1880 1881 // We don't expect assemblers to support integer data directives 1882 // for more than 64 bits, so we emit the data in at most 64-bit 1883 // quantities at a time. 1884 const uint64_t *RawData = Realigned.getRawData(); 1885 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1886 uint64_t Val = DL->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1887 AP.OutStreamer.EmitIntValue(Val, 8); 1888 } 1889 1890 if (ExtraBitsSize) { 1891 // Emit the extra bits after the 64-bits chunks. 1892 1893 // Emit a directive that fills the expected size. 1894 uint64_t Size = AP.TM.getDataLayout()->getTypeAllocSize(CI->getType()); 1895 Size -= (BitWidth / 64) * 8; 1896 assert(Size && Size * 8 >= ExtraBitsSize && 1897 (ExtraBits & (((uint64_t)-1) >> (64 - ExtraBitsSize))) 1898 == ExtraBits && "Directive too small for extra bits."); 1899 AP.OutStreamer.EmitIntValue(ExtraBits, Size); 1900 } 1901} 1902 1903static void emitGlobalConstantImpl(const Constant *CV, AsmPrinter &AP) { 1904 const DataLayout *DL = AP.TM.getDataLayout(); 1905 uint64_t Size = DL->getTypeAllocSize(CV->getType()); 1906 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) 1907 return AP.OutStreamer.EmitZeros(Size); 1908 1909 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1910 switch (Size) { 1911 case 1: 1912 case 2: 1913 case 4: 1914 case 8: 1915 if (AP.isVerbose()) 1916 AP.OutStreamer.GetCommentOS() << format("0x%" PRIx64 "\n", 1917 CI->getZExtValue()); 1918 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size); 1919 return; 1920 default: 1921 emitGlobalConstantLargeInt(CI, AP); 1922 return; 1923 } 1924 } 1925 1926 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1927 return emitGlobalConstantFP(CFP, AP); 1928 1929 if (isa<ConstantPointerNull>(CV)) { 1930 AP.OutStreamer.EmitIntValue(0, Size); 1931 return; 1932 } 1933 1934 if (const ConstantDataSequential *CDS = dyn_cast<ConstantDataSequential>(CV)) 1935 return emitGlobalConstantDataSequential(CDS, AP); 1936 1937 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1938 return emitGlobalConstantArray(CVA, AP); 1939 1940 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1941 return emitGlobalConstantStruct(CVS, AP); 1942 1943 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV)) { 1944 // Look through bitcasts, which might not be able to be MCExpr'ized (e.g. of 1945 // vectors). 1946 if (CE->getOpcode() == Instruction::BitCast) 1947 return emitGlobalConstantImpl(CE->getOperand(0), AP); 1948 1949 if (Size > 8) { 1950 // If the constant expression's size is greater than 64-bits, then we have 1951 // to emit the value in chunks. Try to constant fold the value and emit it 1952 // that way. 1953 Constant *New = ConstantFoldConstantExpression(CE, DL); 1954 if (New && New != CE) 1955 return emitGlobalConstantImpl(New, AP); 1956 } 1957 } 1958 1959 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1960 return emitGlobalConstantVector(V, AP); 1961 1962 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1963 // thread the streamer with EmitValue. 1964 AP.OutStreamer.EmitValue(lowerConstant(CV, AP), Size); 1965} 1966 1967/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1968void AsmPrinter::EmitGlobalConstant(const Constant *CV) { 1969 uint64_t Size = TM.getDataLayout()->getTypeAllocSize(CV->getType()); 1970 if (Size) 1971 emitGlobalConstantImpl(CV, *this); 1972 else if (MAI->hasSubsectionsViaSymbols()) { 1973 // If the global has zero size, emit a single byte so that two labels don't 1974 // look like they are at the same location. 1975 OutStreamer.EmitIntValue(0, 1); 1976 } 1977} 1978 1979void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1980 // Target doesn't support this yet! 1981 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1982} 1983 1984void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1985 if (Offset > 0) 1986 OS << '+' << Offset; 1987 else if (Offset < 0) 1988 OS << Offset; 1989} 1990 1991//===----------------------------------------------------------------------===// 1992// Symbol Lowering Routines. 1993//===----------------------------------------------------------------------===// 1994 1995/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1996/// temporary label with the specified stem and unique ID. 1997MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1998 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1999 Name + Twine(ID)); 2000} 2001 2002/// GetTempSymbol - Return an assembler temporary label with the specified 2003/// stem. 2004MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 2005 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 2006 Name); 2007} 2008 2009 2010MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 2011 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 2012} 2013 2014MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 2015 return MMI->getAddrLabelSymbol(BB); 2016} 2017 2018/// GetCPISymbol - Return the symbol for the specified constant pool entry. 2019MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 2020 return OutContext.GetOrCreateSymbol 2021 (Twine(MAI->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 return OutContext.GetOrCreateSymbol 2034 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 2035 Twine(UID) + "_set_" + Twine(MBBID)); 2036} 2037 2038/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 2039/// global value name as its base, with the specified suffix, and where the 2040/// symbol is forced to have private linkage if ForcePrivate is true. 2041MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 2042 StringRef Suffix, 2043 bool ForcePrivate) const { 2044 SmallString<60> NameStr; 2045 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 2046 NameStr.append(Suffix.begin(), Suffix.end()); 2047 return OutContext.GetOrCreateSymbol(NameStr.str()); 2048} 2049 2050/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 2051/// ExternalSymbol. 2052MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 2053 SmallString<60> NameStr; 2054 Mang->getNameWithPrefix(NameStr, Sym); 2055 return OutContext.GetOrCreateSymbol(NameStr.str()); 2056} 2057 2058 2059 2060/// PrintParentLoopComment - Print comments about parent loops of this one. 2061static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2062 unsigned FunctionNumber) { 2063 if (Loop == 0) return; 2064 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 2065 OS.indent(Loop->getLoopDepth()*2) 2066 << "Parent Loop BB" << FunctionNumber << "_" 2067 << Loop->getHeader()->getNumber() 2068 << " Depth=" << Loop->getLoopDepth() << '\n'; 2069} 2070 2071 2072/// PrintChildLoopComment - Print comments about child loops within 2073/// the loop for this basic block, with nesting. 2074static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 2075 unsigned FunctionNumber) { 2076 // Add child loop information 2077 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 2078 OS.indent((*CL)->getLoopDepth()*2) 2079 << "Child Loop BB" << FunctionNumber << "_" 2080 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 2081 << '\n'; 2082 PrintChildLoopComment(OS, *CL, FunctionNumber); 2083 } 2084} 2085 2086/// emitBasicBlockLoopComments - Pretty-print comments for basic blocks. 2087static void emitBasicBlockLoopComments(const MachineBasicBlock &MBB, 2088 const MachineLoopInfo *LI, 2089 const AsmPrinter &AP) { 2090 // Add loop depth information 2091 const MachineLoop *Loop = LI->getLoopFor(&MBB); 2092 if (Loop == 0) return; 2093 2094 MachineBasicBlock *Header = Loop->getHeader(); 2095 assert(Header && "No header for loop"); 2096 2097 // If this block is not a loop header, just print out what is the loop header 2098 // and return. 2099 if (Header != &MBB) { 2100 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 2101 Twine(AP.getFunctionNumber())+"_" + 2102 Twine(Loop->getHeader()->getNumber())+ 2103 " Depth="+Twine(Loop->getLoopDepth())); 2104 return; 2105 } 2106 2107 // Otherwise, it is a loop header. Print out information about child and 2108 // parent loops. 2109 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 2110 2111 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 2112 2113 OS << "=>"; 2114 OS.indent(Loop->getLoopDepth()*2-2); 2115 2116 OS << "This "; 2117 if (Loop->empty()) 2118 OS << "Inner "; 2119 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 2120 2121 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 2122} 2123 2124 2125/// EmitBasicBlockStart - This method prints the label for the specified 2126/// MachineBasicBlock, an alignment (if present) and a comment describing 2127/// it if appropriate. 2128void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 2129 // Emit an alignment directive for this block, if needed. 2130 if (unsigned Align = MBB->getAlignment()) 2131 EmitAlignment(Align); 2132 2133 // If the block has its address taken, emit any labels that were used to 2134 // reference the block. It is possible that there is more than one label 2135 // here, because multiple LLVM BB's may have been RAUW'd to this block after 2136 // the references were generated. 2137 if (MBB->hasAddressTaken()) { 2138 const BasicBlock *BB = MBB->getBasicBlock(); 2139 if (isVerbose()) 2140 OutStreamer.AddComment("Block address taken"); 2141 2142 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 2143 2144 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 2145 OutStreamer.EmitLabel(Syms[i]); 2146 } 2147 2148 // Print some verbose block comments. 2149 if (isVerbose()) { 2150 if (const BasicBlock *BB = MBB->getBasicBlock()) 2151 if (BB->hasName()) 2152 OutStreamer.AddComment("%" + BB->getName()); 2153 emitBasicBlockLoopComments(*MBB, LI, *this); 2154 } 2155 2156 // Print the main label for the block. 2157 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 2158 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 2159 // NOTE: Want this comment at start of line, don't emit with AddComment. 2160 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 2161 Twine(MBB->getNumber()) + ":"); 2162 } 2163 } else { 2164 OutStreamer.EmitLabel(MBB->getSymbol()); 2165 } 2166} 2167 2168void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 2169 bool IsDefinition) const { 2170 MCSymbolAttr Attr = MCSA_Invalid; 2171 2172 switch (Visibility) { 2173 default: break; 2174 case GlobalValue::HiddenVisibility: 2175 if (IsDefinition) 2176 Attr = MAI->getHiddenVisibilityAttr(); 2177 else 2178 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 2179 break; 2180 case GlobalValue::ProtectedVisibility: 2181 Attr = MAI->getProtectedVisibilityAttr(); 2182 break; 2183 } 2184 2185 if (Attr != MCSA_Invalid) 2186 OutStreamer.EmitSymbolAttribute(Sym, Attr); 2187} 2188 2189/// isBlockOnlyReachableByFallthough - Return true if the basic block has 2190/// exactly one predecessor and the control transfer mechanism between 2191/// the predecessor and this block is a fall-through. 2192bool AsmPrinter:: 2193isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 2194 // If this is a landing pad, it isn't a fall through. If it has no preds, 2195 // then nothing falls through to it. 2196 if (MBB->isLandingPad() || MBB->pred_empty()) 2197 return false; 2198 2199 // If there isn't exactly one predecessor, it can't be a fall through. 2200 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 2201 ++PI2; 2202 if (PI2 != MBB->pred_end()) 2203 return false; 2204 2205 // The predecessor has to be immediately before this block. 2206 MachineBasicBlock *Pred = *PI; 2207 2208 if (!Pred->isLayoutSuccessor(MBB)) 2209 return false; 2210 2211 // If the block is completely empty, then it definitely does fall through. 2212 if (Pred->empty()) 2213 return true; 2214 2215 // Check the terminators in the previous blocks 2216 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(), 2217 IE = Pred->end(); II != IE; ++II) { 2218 MachineInstr &MI = *II; 2219 2220 // If it is not a simple branch, we are in a table somewhere. 2221 if (!MI.isBranch() || MI.isIndirectBranch()) 2222 return false; 2223 2224 // If we are the operands of one of the branches, this is not 2225 // a fall through. 2226 for (MachineInstr::mop_iterator OI = MI.operands_begin(), 2227 OE = MI.operands_end(); OI != OE; ++OI) { 2228 const MachineOperand& OP = *OI; 2229 if (OP.isJTI()) 2230 return false; 2231 if (OP.isMBB() && OP.getMBB() == MBB) 2232 return false; 2233 } 2234 } 2235 2236 return true; 2237} 2238 2239 2240 2241GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 2242 if (!S->usesMetadata()) 2243 return 0; 2244 2245 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 2246 gcp_map_type::iterator GCPI = GCMap.find(S); 2247 if (GCPI != GCMap.end()) 2248 return GCPI->second; 2249 2250 const char *Name = S->getName().c_str(); 2251 2252 for (GCMetadataPrinterRegistry::iterator 2253 I = GCMetadataPrinterRegistry::begin(), 2254 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 2255 if (strcmp(Name, I->getName()) == 0) { 2256 GCMetadataPrinter *GMP = I->instantiate(); 2257 GMP->S = S; 2258 GCMap.insert(std::make_pair(S, GMP)); 2259 return GMP; 2260 } 2261 2262 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 2263} 2264