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/Module.h" 19 #include "llvm/CodeGen/GCMetadataPrinter.h" 20 #include "llvm/CodeGen/MachineConstantPool.h" 21 #include "llvm/CodeGen/MachineFrameInfo.h" 22 #include "llvm/CodeGen/MachineFunction.h" 23 #include "llvm/CodeGen/MachineJumpTableInfo.h" 24 #include "llvm/CodeGen/MachineLoopInfo.h" 25 #include "llvm/CodeGen/MachineModuleInfo.h" 26 #include "llvm/Analysis/ConstantFolding.h" 27 #include "llvm/Analysis/DebugInfo.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" 49 using namespace llvm; 50 51 static const char *DWARFGroupName = "DWARF Emission"; 52 static const char *DbgTimerName = "DWARF Debug Writer"; 53 static const char *EHTimerName = "DWARF Exception Writer"; 54 55 STATISTIC(EmittedInsts, "Number of machine instrs printed"); 56 57 char AsmPrinter::ID = 0; 58 59 typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 60 static 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. 70 static 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 96 AsmPrinter::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 GCMetadataPrinters = 0; 104 VerboseAsm = Streamer.isVerboseAsm(); 105 } 106 107 AsmPrinter::~AsmPrinter() { 108 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 109 110 if (GCMetadataPrinters != 0) { 111 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 112 113 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 114 delete I->second; 115 delete &GCMap; 116 GCMetadataPrinters = 0; 117 } 118 119 delete &OutStreamer; 120 } 121 122 /// getFunctionNumber - Return a unique ID for the current function. 123 /// 124 unsigned AsmPrinter::getFunctionNumber() const { 125 return MF->getFunctionNumber(); 126 } 127 128 const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 129 return TM.getTargetLowering()->getObjFileLowering(); 130 } 131 132 133 /// getTargetData - Return information about data layout. 134 const TargetData &AsmPrinter::getTargetData() const { 135 return *TM.getTargetData(); 136 } 137 138 /// getCurrentSection() - Return the current section we are emitting to. 139 const MCSection *AsmPrinter::getCurrentSection() const { 140 return OutStreamer.getCurrentSection(); 141 } 142 143 144 145 void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 146 AU.setPreservesAll(); 147 MachineFunctionPass::getAnalysisUsage(AU); 148 AU.addRequired<MachineModuleInfo>(); 149 AU.addRequired<GCModuleInfo>(); 150 if (isVerbose()) 151 AU.addRequired<MachineLoopInfo>(); 152 } 153 154 bool AsmPrinter::doInitialization(Module &M) { 155 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 156 MMI->AnalyzeModule(M); 157 158 // Initialize TargetLoweringObjectFile. 159 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 160 .Initialize(OutContext, TM); 161 162 Mang = new Mangler(OutContext, *TM.getTargetData()); 163 164 // Allow the target to emit any magic that it wants at the start of the file. 165 EmitStartOfAsmFile(M); 166 167 // Very minimal debug info. It is ignored if we emit actual debug info. If we 168 // don't, this at least helps the user find where a global came from. 169 if (MAI->hasSingleParameterDotFile()) { 170 // .file "foo.c" 171 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 172 } 173 174 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 175 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 176 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 177 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 178 MP->beginAssembly(*this); 179 180 // Emit module-level inline asm if it exists. 181 if (!M.getModuleInlineAsm().empty()) { 182 OutStreamer.AddComment("Start of file scope inline assembly"); 183 OutStreamer.AddBlankLine(); 184 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 185 OutStreamer.AddComment("End of file scope inline assembly"); 186 OutStreamer.AddBlankLine(); 187 } 188 189 if (MAI->doesSupportDebugInformation()) 190 DD = new DwarfDebug(this, &M); 191 192 switch (MAI->getExceptionHandlingType()) { 193 case ExceptionHandling::None: 194 return false; 195 case ExceptionHandling::SjLj: 196 case ExceptionHandling::DwarfCFI: 197 DE = new DwarfCFIException(this); 198 return false; 199 case ExceptionHandling::ARM: 200 DE = new ARMException(this); 201 return false; 202 case ExceptionHandling::Win64: 203 DE = new Win64Exception(this); 204 return false; 205 } 206 207 llvm_unreachable("Unknown exception type."); 208 } 209 210 void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 211 switch ((GlobalValue::LinkageTypes)Linkage) { 212 case GlobalValue::CommonLinkage: 213 case GlobalValue::LinkOnceAnyLinkage: 214 case GlobalValue::LinkOnceODRLinkage: 215 case GlobalValue::WeakAnyLinkage: 216 case GlobalValue::WeakODRLinkage: 217 case GlobalValue::LinkerPrivateWeakLinkage: 218 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 219 if (MAI->getWeakDefDirective() != 0) { 220 // .globl _foo 221 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 222 223 if ((GlobalValue::LinkageTypes)Linkage != 224 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 225 // .weak_definition _foo 226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 227 else 228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 229 } else if (MAI->getLinkOnceDirective() != 0) { 230 // .globl _foo 231 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 232 //NOTE: linkonce is handled by the section the symbol was assigned to. 233 } else { 234 // .weak _foo 235 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 236 } 237 break; 238 case GlobalValue::DLLExportLinkage: 239 case GlobalValue::AppendingLinkage: 240 // FIXME: appending linkage variables should go into a section of 241 // their name or something. For now, just emit them as external. 242 case GlobalValue::ExternalLinkage: 243 // If external or appending, declare as a global symbol. 244 // .globl _foo 245 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 246 break; 247 case GlobalValue::PrivateLinkage: 248 case GlobalValue::InternalLinkage: 249 case GlobalValue::LinkerPrivateLinkage: 250 break; 251 default: 252 llvm_unreachable("Unknown linkage type!"); 253 } 254 } 255 256 257 /// EmitGlobalVariable - Emit the specified global variable to the .s file. 258 void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 259 if (GV->hasInitializer()) { 260 // Check to see if this is a special global used by LLVM, if so, emit it. 261 if (EmitSpecialLLVMGlobal(GV)) 262 return; 263 264 if (isVerbose()) { 265 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 266 /*PrintType=*/false, GV->getParent()); 267 OutStreamer.GetCommentOS() << '\n'; 268 } 269 } 270 271 MCSymbol *GVSym = Mang->getSymbol(GV); 272 EmitVisibility(GVSym, GV->getVisibility(), !GV->isDeclaration()); 273 274 if (!GV->hasInitializer()) // External globals require no extra code. 275 return; 276 277 if (MAI->hasDotTypeDotSizeDirective()) 278 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 279 280 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 281 282 const TargetData *TD = TM.getTargetData(); 283 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 284 285 // If the alignment is specified, we *must* obey it. Overaligning a global 286 // with a specified alignment is a prompt way to break globals emitted to 287 // sections and expected to be contiguous (e.g. ObjC metadata). 288 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 289 290 // Handle common and BSS local symbols (.lcomm). 291 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 292 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 293 unsigned Align = 1 << AlignLog; 294 295 // Handle common symbols. 296 if (GVKind.isCommon()) { 297 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 298 Align = 0; 299 300 // .comm _foo, 42, 4 301 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 302 return; 303 } 304 305 // Handle local BSS symbols. 306 if (MAI->hasMachoZeroFillDirective()) { 307 const MCSection *TheSection = 308 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 309 // .zerofill __DATA, __bss, _foo, 400, 5 310 OutStreamer.EmitZerofill(TheSection, GVSym, Size, Align); 311 return; 312 } 313 314 if (MAI->getLCOMMDirectiveType() != LCOMM::None && 315 (MAI->getLCOMMDirectiveType() != LCOMM::NoAlignment || Align == 1)) { 316 // .lcomm _foo, 42 317 OutStreamer.EmitLocalCommonSymbol(GVSym, Size, Align); 318 return; 319 } 320 321 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 322 Align = 0; 323 324 // .local _foo 325 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 326 // .comm _foo, 42, 4 327 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 328 return; 329 } 330 331 const MCSection *TheSection = 332 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 333 334 // Handle the zerofill directive on darwin, which is a special form of BSS 335 // emission. 336 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 337 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 338 339 // .globl _foo 340 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 341 // .zerofill __DATA, __common, _foo, 400, 5 342 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 343 return; 344 } 345 346 // Handle thread local data for mach-o which requires us to output an 347 // additional structure of data and mangle the original symbol so that we 348 // can reference it later. 349 // 350 // TODO: This should become an "emit thread local global" method on TLOF. 351 // All of this macho specific stuff should be sunk down into TLOFMachO and 352 // stuff like "TLSExtraDataSection" should no longer be part of the parent 353 // TLOF class. This will also make it more obvious that stuff like 354 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 355 // specific code. 356 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 357 // Emit the .tbss symbol 358 MCSymbol *MangSym = 359 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 360 361 if (GVKind.isThreadBSS()) 362 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 363 else if (GVKind.isThreadData()) { 364 OutStreamer.SwitchSection(TheSection); 365 366 EmitAlignment(AlignLog, GV); 367 OutStreamer.EmitLabel(MangSym); 368 369 EmitGlobalConstant(GV->getInitializer()); 370 } 371 372 OutStreamer.AddBlankLine(); 373 374 // Emit the variable struct for the runtime. 375 const MCSection *TLVSect 376 = getObjFileLowering().getTLSExtraDataSection(); 377 378 OutStreamer.SwitchSection(TLVSect); 379 // Emit the linkage here. 380 EmitLinkage(GV->getLinkage(), GVSym); 381 OutStreamer.EmitLabel(GVSym); 382 383 // Three pointers in size: 384 // - __tlv_bootstrap - used to make sure support exists 385 // - spare pointer, used when mapped by the runtime 386 // - pointer to mangled symbol above with initializer 387 unsigned PtrSize = TD->getPointerSizeInBits()/8; 388 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 389 PtrSize, 0); 390 OutStreamer.EmitIntValue(0, PtrSize, 0); 391 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 392 393 OutStreamer.AddBlankLine(); 394 return; 395 } 396 397 OutStreamer.SwitchSection(TheSection); 398 399 EmitLinkage(GV->getLinkage(), GVSym); 400 EmitAlignment(AlignLog, GV); 401 402 OutStreamer.EmitLabel(GVSym); 403 404 EmitGlobalConstant(GV->getInitializer()); 405 406 if (MAI->hasDotTypeDotSizeDirective()) 407 // .size foo, 42 408 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 409 410 OutStreamer.AddBlankLine(); 411 } 412 413 /// EmitFunctionHeader - This method emits the header for the current 414 /// function. 415 void AsmPrinter::EmitFunctionHeader() { 416 // Print out constants referenced by the function 417 EmitConstantPool(); 418 419 // Print the 'header' of function. 420 const Function *F = MF->getFunction(); 421 422 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 423 EmitVisibility(CurrentFnSym, F->getVisibility()); 424 425 EmitLinkage(F->getLinkage(), CurrentFnSym); 426 EmitAlignment(MF->getAlignment(), F); 427 428 if (MAI->hasDotTypeDotSizeDirective()) 429 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 430 431 if (isVerbose()) { 432 WriteAsOperand(OutStreamer.GetCommentOS(), F, 433 /*PrintType=*/false, F->getParent()); 434 OutStreamer.GetCommentOS() << '\n'; 435 } 436 437 // Emit the CurrentFnSym. This is a virtual function to allow targets to 438 // do their wild and crazy things as required. 439 EmitFunctionEntryLabel(); 440 441 // If the function had address-taken blocks that got deleted, then we have 442 // references to the dangling symbols. Emit them at the start of the function 443 // so that we don't get references to undefined symbols. 444 std::vector<MCSymbol*> DeadBlockSyms; 445 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 446 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 447 OutStreamer.AddComment("Address taken block that was later removed"); 448 OutStreamer.EmitLabel(DeadBlockSyms[i]); 449 } 450 451 // Add some workaround for linkonce linkage on Cygwin\MinGW. 452 if (MAI->getLinkOnceDirective() != 0 && 453 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 454 // FIXME: What is this? 455 MCSymbol *FakeStub = 456 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 457 CurrentFnSym->getName()); 458 OutStreamer.EmitLabel(FakeStub); 459 } 460 461 // Emit pre-function debug and/or EH information. 462 if (DE) { 463 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 464 DE->BeginFunction(MF); 465 } 466 if (DD) { 467 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 468 DD->beginFunction(MF); 469 } 470 } 471 472 /// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 473 /// function. This can be overridden by targets as required to do custom stuff. 474 void AsmPrinter::EmitFunctionEntryLabel() { 475 // The function label could have already been emitted if two symbols end up 476 // conflicting due to asm renaming. Detect this and emit an error. 477 if (CurrentFnSym->isUndefined()) { 478 OutStreamer.ForceCodeRegion(); 479 return OutStreamer.EmitLabel(CurrentFnSym); 480 } 481 482 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 483 "' label emitted multiple times to assembly file"); 484 } 485 486 487 /// EmitComments - Pretty-print comments for instructions. 488 static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 489 const MachineFunction *MF = MI.getParent()->getParent(); 490 const TargetMachine &TM = MF->getTarget(); 491 492 // Check for spills and reloads 493 int FI; 494 495 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 496 497 // We assume a single instruction only has a spill or reload, not 498 // both. 499 const MachineMemOperand *MMO; 500 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 501 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 502 MMO = *MI.memoperands_begin(); 503 CommentOS << MMO->getSize() << "-byte Reload\n"; 504 } 505 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 506 if (FrameInfo->isSpillSlotObjectIndex(FI)) 507 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 508 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 509 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 510 MMO = *MI.memoperands_begin(); 511 CommentOS << MMO->getSize() << "-byte Spill\n"; 512 } 513 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 514 if (FrameInfo->isSpillSlotObjectIndex(FI)) 515 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 516 } 517 518 // Check for spill-induced copies 519 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 520 CommentOS << " Reload Reuse\n"; 521 } 522 523 /// EmitImplicitDef - This method emits the specified machine instruction 524 /// that is an implicit def. 525 static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 526 unsigned RegNo = MI->getOperand(0).getReg(); 527 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 528 AP.TM.getRegisterInfo()->getName(RegNo)); 529 AP.OutStreamer.AddBlankLine(); 530 } 531 532 static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 533 std::string Str = "kill:"; 534 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 535 const MachineOperand &Op = MI->getOperand(i); 536 assert(Op.isReg() && "KILL instruction must have only register operands"); 537 Str += ' '; 538 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 539 Str += (Op.isDef() ? "<def>" : "<kill>"); 540 } 541 AP.OutStreamer.AddComment(Str); 542 AP.OutStreamer.AddBlankLine(); 543 } 544 545 /// EmitDebugValueComment - This method handles the target-independent form 546 /// of DBG_VALUE, returning true if it was able to do so. A false return 547 /// means the target will need to handle MI in EmitInstruction. 548 static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 549 // This code handles only the 3-operand target-independent form. 550 if (MI->getNumOperands() != 3) 551 return false; 552 553 SmallString<128> Str; 554 raw_svector_ostream OS(Str); 555 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 556 557 // cast away const; DIetc do not take const operands for some reason. 558 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 559 if (V.getContext().isSubprogram()) 560 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 561 OS << V.getName() << " <- "; 562 563 // Register or immediate value. Register 0 means undef. 564 if (MI->getOperand(0).isFPImm()) { 565 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 566 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 567 OS << (double)APF.convertToFloat(); 568 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 569 OS << APF.convertToDouble(); 570 } else { 571 // There is no good way to print long double. Convert a copy to 572 // double. Ah well, it's only a comment. 573 bool ignored; 574 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 575 &ignored); 576 OS << "(long double) " << APF.convertToDouble(); 577 } 578 } else if (MI->getOperand(0).isImm()) { 579 OS << MI->getOperand(0).getImm(); 580 } else if (MI->getOperand(0).isCImm()) { 581 MI->getOperand(0).getCImm()->getValue().print(OS, false /*isSigned*/); 582 } else { 583 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 584 if (MI->getOperand(0).getReg() == 0) { 585 // Suppress offset, it is not meaningful here. 586 OS << "undef"; 587 // NOTE: Want this comment at start of line, don't emit with AddComment. 588 AP.OutStreamer.EmitRawText(OS.str()); 589 return true; 590 } 591 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 592 } 593 594 OS << '+' << MI->getOperand(1).getImm(); 595 // NOTE: Want this comment at start of line, don't emit with AddComment. 596 AP.OutStreamer.EmitRawText(OS.str()); 597 return true; 598 } 599 600 AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() { 601 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI && 602 MF->getFunction()->needsUnwindTableEntry()) 603 return CFI_M_EH; 604 605 if (MMI->hasDebugInfo()) 606 return CFI_M_Debug; 607 608 return CFI_M_None; 609 } 610 611 bool AsmPrinter::needsSEHMoves() { 612 return MAI->getExceptionHandlingType() == ExceptionHandling::Win64 && 613 MF->getFunction()->needsUnwindTableEntry(); 614 } 615 616 void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 617 MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 618 619 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) 620 return; 621 622 if (needsCFIMoves() == CFI_M_None) 623 return; 624 625 if (MMI->getCompactUnwindEncoding() != 0) 626 OutStreamer.EmitCompactUnwindEncoding(MMI->getCompactUnwindEncoding()); 627 628 MachineModuleInfo &MMI = MF->getMMI(); 629 std::vector<MachineMove> &Moves = MMI.getFrameMoves(); 630 bool FoundOne = false; 631 (void)FoundOne; 632 for (std::vector<MachineMove>::iterator I = Moves.begin(), 633 E = Moves.end(); I != E; ++I) { 634 if (I->getLabel() == Label) { 635 EmitCFIFrameMove(*I); 636 FoundOne = true; 637 } 638 } 639 assert(FoundOne); 640 } 641 642 /// EmitFunctionBody - This method emits the body and trailer for a 643 /// function. 644 void AsmPrinter::EmitFunctionBody() { 645 // Emit target-specific gunk before the function body. 646 EmitFunctionBodyStart(); 647 648 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 649 650 // Print out code for the function. 651 bool HasAnyRealCode = false; 652 const MachineInstr *LastMI = 0; 653 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 654 I != E; ++I) { 655 // Print a label for the basic block. 656 EmitBasicBlockStart(I); 657 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 658 II != IE; ++II) { 659 LastMI = II; 660 661 // Print the assembly for the instruction. 662 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 663 !II->isDebugValue()) { 664 HasAnyRealCode = true; 665 ++EmittedInsts; 666 } 667 668 if (ShouldPrintDebugScopes) { 669 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 670 DD->beginInstruction(II); 671 } 672 673 if (isVerbose()) 674 EmitComments(*II, OutStreamer.GetCommentOS()); 675 676 switch (II->getOpcode()) { 677 case TargetOpcode::PROLOG_LABEL: 678 emitPrologLabel(*II); 679 break; 680 681 case TargetOpcode::EH_LABEL: 682 case TargetOpcode::GC_LABEL: 683 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 684 break; 685 case TargetOpcode::INLINEASM: 686 EmitInlineAsm(II); 687 break; 688 case TargetOpcode::DBG_VALUE: 689 if (isVerbose()) { 690 if (!EmitDebugValueComment(II, *this)) 691 EmitInstruction(II); 692 } 693 break; 694 case TargetOpcode::IMPLICIT_DEF: 695 if (isVerbose()) EmitImplicitDef(II, *this); 696 break; 697 case TargetOpcode::KILL: 698 if (isVerbose()) EmitKill(II, *this); 699 break; 700 default: 701 if (!TM.hasMCUseLoc()) 702 MCLineEntry::Make(&OutStreamer, getCurrentSection()); 703 704 EmitInstruction(II); 705 break; 706 } 707 708 if (ShouldPrintDebugScopes) { 709 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 710 DD->endInstruction(II); 711 } 712 } 713 } 714 715 // If the last instruction was a prolog label, then we have a situation where 716 // we emitted a prolog but no function body. This results in the ending prolog 717 // label equaling the end of function label and an invalid "row" in the 718 // FDE. We need to emit a noop in this situation so that the FDE's rows are 719 // valid. 720 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 721 722 // If the function is empty and the object file uses .subsections_via_symbols, 723 // then we need to emit *something* to the function body to prevent the 724 // labels from collapsing together. Just emit a noop. 725 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 726 MCInst Noop; 727 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 728 if (Noop.getOpcode()) { 729 OutStreamer.AddComment("avoids zero-length function"); 730 OutStreamer.EmitInstruction(Noop); 731 } else // Target not mc-ized yet. 732 OutStreamer.EmitRawText(StringRef("\tnop\n")); 733 } 734 735 // Emit target-specific gunk after the function body. 736 EmitFunctionBodyEnd(); 737 738 // If the target wants a .size directive for the size of the function, emit 739 // it. 740 if (MAI->hasDotTypeDotSizeDirective()) { 741 // Create a symbol for the end of function, so we can get the size as 742 // difference between the function label and the temp label. 743 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 744 OutStreamer.EmitLabel(FnEndLabel); 745 746 const MCExpr *SizeExp = 747 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 748 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 749 OutContext); 750 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 751 } 752 753 // Emit post-function debug information. 754 if (DD) { 755 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 756 DD->endFunction(MF); 757 } 758 if (DE) { 759 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 760 DE->EndFunction(); 761 } 762 MMI->EndFunction(); 763 764 // Print out jump tables referenced by the function. 765 EmitJumpTableInfo(); 766 767 OutStreamer.AddBlankLine(); 768 } 769 770 /// getDebugValueLocation - Get location information encoded by DBG_VALUE 771 /// operands. 772 MachineLocation AsmPrinter:: 773 getDebugValueLocation(const MachineInstr *MI) const { 774 // Target specific DBG_VALUE instructions are handled by each target. 775 return MachineLocation(); 776 } 777 778 /// EmitDwarfRegOp - Emit dwarf register operation. 779 void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const { 780 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 781 int Reg = TRI->getDwarfRegNum(MLoc.getReg(), false); 782 783 for (const unsigned *SR = TRI->getSuperRegisters(MLoc.getReg()); 784 *SR && Reg < 0; ++SR) { 785 Reg = TRI->getDwarfRegNum(*SR, false); 786 // FIXME: Get the bit range this register uses of the superregister 787 // so that we can produce a DW_OP_bit_piece 788 } 789 790 // FIXME: Handle cases like a super register being encoded as 791 // DW_OP_reg 32 DW_OP_piece 4 DW_OP_reg 33 792 793 // FIXME: We have no reasonable way of handling errors in here. The 794 // caller might be in the middle of an dwarf expression. We should 795 // probably assert that Reg >= 0 once debug info generation is more mature. 796 797 if (int Offset = MLoc.getOffset()) { 798 if (Reg < 32) { 799 OutStreamer.AddComment( 800 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg)); 801 EmitInt8(dwarf::DW_OP_breg0 + Reg); 802 } else { 803 OutStreamer.AddComment("DW_OP_bregx"); 804 EmitInt8(dwarf::DW_OP_bregx); 805 OutStreamer.AddComment(Twine(Reg)); 806 EmitULEB128(Reg); 807 } 808 EmitSLEB128(Offset); 809 } else { 810 if (Reg < 32) { 811 OutStreamer.AddComment( 812 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg)); 813 EmitInt8(dwarf::DW_OP_reg0 + Reg); 814 } else { 815 OutStreamer.AddComment("DW_OP_regx"); 816 EmitInt8(dwarf::DW_OP_regx); 817 OutStreamer.AddComment(Twine(Reg)); 818 EmitULEB128(Reg); 819 } 820 } 821 822 // FIXME: Produce a DW_OP_bit_piece if we used a superregister 823 } 824 825 bool AsmPrinter::doFinalization(Module &M) { 826 // Emit global variables. 827 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 828 I != E; ++I) 829 EmitGlobalVariable(I); 830 831 // Emit visibility info for declarations 832 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 833 const Function &F = *I; 834 if (!F.isDeclaration()) 835 continue; 836 GlobalValue::VisibilityTypes V = F.getVisibility(); 837 if (V == GlobalValue::DefaultVisibility) 838 continue; 839 840 MCSymbol *Name = Mang->getSymbol(&F); 841 EmitVisibility(Name, V, false); 842 } 843 844 // Finalize debug and EH information. 845 if (DE) { 846 { 847 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 848 DE->EndModule(); 849 } 850 delete DE; DE = 0; 851 } 852 if (DD) { 853 { 854 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 855 DD->endModule(); 856 } 857 delete DD; DD = 0; 858 } 859 860 // If the target wants to know about weak references, print them all. 861 if (MAI->getWeakRefDirective()) { 862 // FIXME: This is not lazy, it would be nice to only print weak references 863 // to stuff that is actually used. Note that doing so would require targets 864 // to notice uses in operands (due to constant exprs etc). This should 865 // happen with the MC stuff eventually. 866 867 // Print out module-level global variables here. 868 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 869 I != E; ++I) { 870 if (!I->hasExternalWeakLinkage()) continue; 871 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 872 } 873 874 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 875 if (!I->hasExternalWeakLinkage()) continue; 876 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 877 } 878 } 879 880 if (MAI->hasSetDirective()) { 881 OutStreamer.AddBlankLine(); 882 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 883 I != E; ++I) { 884 MCSymbol *Name = Mang->getSymbol(I); 885 886 const GlobalValue *GV = I->getAliasedGlobal(); 887 MCSymbol *Target = Mang->getSymbol(GV); 888 889 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 890 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 891 else if (I->hasWeakLinkage()) 892 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 893 else 894 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 895 896 EmitVisibility(Name, I->getVisibility()); 897 898 // Emit the directives as assignments aka .set: 899 OutStreamer.EmitAssignment(Name, 900 MCSymbolRefExpr::Create(Target, OutContext)); 901 } 902 } 903 904 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 905 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 906 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 907 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 908 MP->finishAssembly(*this); 909 910 // If we don't have any trampolines, then we don't require stack memory 911 // to be executable. Some targets have a directive to declare this. 912 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 913 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 914 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 915 OutStreamer.SwitchSection(S); 916 917 // Allow the target to emit any magic that it wants at the end of the file, 918 // after everything else has gone out. 919 EmitEndOfAsmFile(M); 920 921 delete Mang; Mang = 0; 922 MMI = 0; 923 924 OutStreamer.Finish(); 925 return false; 926 } 927 928 void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 929 this->MF = &MF; 930 // Get the function symbol. 931 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 932 933 if (isVerbose()) 934 LI = &getAnalysis<MachineLoopInfo>(); 935 } 936 937 namespace { 938 // SectionCPs - Keep track the alignment, constpool entries per Section. 939 struct SectionCPs { 940 const MCSection *S; 941 unsigned Alignment; 942 SmallVector<unsigned, 4> CPEs; 943 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 944 }; 945 } 946 947 /// EmitConstantPool - Print to the current output stream assembly 948 /// representations of the constants in the constant pool MCP. This is 949 /// used to print out constants which have been "spilled to memory" by 950 /// the code generator. 951 /// 952 void AsmPrinter::EmitConstantPool() { 953 const MachineConstantPool *MCP = MF->getConstantPool(); 954 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 955 if (CP.empty()) return; 956 957 // Calculate sections for constant pool entries. We collect entries to go into 958 // the same section together to reduce amount of section switch statements. 959 SmallVector<SectionCPs, 4> CPSections; 960 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 961 const MachineConstantPoolEntry &CPE = CP[i]; 962 unsigned Align = CPE.getAlignment(); 963 964 SectionKind Kind; 965 switch (CPE.getRelocationInfo()) { 966 default: llvm_unreachable("Unknown section kind"); 967 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 968 case 1: 969 Kind = SectionKind::getReadOnlyWithRelLocal(); 970 break; 971 case 0: 972 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 973 case 4: Kind = SectionKind::getMergeableConst4(); break; 974 case 8: Kind = SectionKind::getMergeableConst8(); break; 975 case 16: Kind = SectionKind::getMergeableConst16();break; 976 default: Kind = SectionKind::getMergeableConst(); break; 977 } 978 } 979 980 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 981 982 // The number of sections are small, just do a linear search from the 983 // last section to the first. 984 bool Found = false; 985 unsigned SecIdx = CPSections.size(); 986 while (SecIdx != 0) { 987 if (CPSections[--SecIdx].S == S) { 988 Found = true; 989 break; 990 } 991 } 992 if (!Found) { 993 SecIdx = CPSections.size(); 994 CPSections.push_back(SectionCPs(S, Align)); 995 } 996 997 if (Align > CPSections[SecIdx].Alignment) 998 CPSections[SecIdx].Alignment = Align; 999 CPSections[SecIdx].CPEs.push_back(i); 1000 } 1001 1002 // Now print stuff into the calculated sections. 1003 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 1004 OutStreamer.SwitchSection(CPSections[i].S); 1005 EmitAlignment(Log2_32(CPSections[i].Alignment)); 1006 1007 unsigned Offset = 0; 1008 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 1009 unsigned CPI = CPSections[i].CPEs[j]; 1010 MachineConstantPoolEntry CPE = CP[CPI]; 1011 1012 // Emit inter-object padding for alignment. 1013 unsigned AlignMask = CPE.getAlignment() - 1; 1014 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 1015 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 1016 1017 Type *Ty = CPE.getType(); 1018 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 1019 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 1020 1021 if (CPE.isMachineConstantPoolEntry()) 1022 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 1023 else 1024 EmitGlobalConstant(CPE.Val.ConstVal); 1025 } 1026 } 1027 } 1028 1029 /// EmitJumpTableInfo - Print assembly representations of the jump tables used 1030 /// by the current function to the current output stream. 1031 /// 1032 void AsmPrinter::EmitJumpTableInfo() { 1033 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1034 if (MJTI == 0) return; 1035 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1036 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1037 if (JT.empty()) return; 1038 1039 // Pick the directive to use to print the jump table entries, and switch to 1040 // the appropriate section. 1041 const Function *F = MF->getFunction(); 1042 bool JTInDiffSection = false; 1043 if (// In PIC mode, we need to emit the jump table to the same section as the 1044 // function body itself, otherwise the label differences won't make sense. 1045 // FIXME: Need a better predicate for this: what about custom entries? 1046 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1047 // We should also do if the section name is NULL or function is declared 1048 // in discardable section 1049 // FIXME: this isn't the right predicate, should be based on the MCSection 1050 // for the function. 1051 F->isWeakForLinker()) { 1052 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 1053 } else { 1054 // Otherwise, drop it in the readonly section. 1055 const MCSection *ReadOnlySection = 1056 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1057 OutStreamer.SwitchSection(ReadOnlySection); 1058 JTInDiffSection = true; 1059 } 1060 1061 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 1062 1063 // If we know the form of the jump table, go ahead and tag it as such. 1064 if (!JTInDiffSection) { 1065 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32) { 1066 OutStreamer.EmitJumpTable32Region(); 1067 } else { 1068 OutStreamer.EmitDataRegion(); 1069 } 1070 } 1071 1072 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1073 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1074 1075 // If this jump table was deleted, ignore it. 1076 if (JTBBs.empty()) continue; 1077 1078 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1079 // .set directive for each unique entry. This reduces the number of 1080 // relocations the assembler will generate for the jump table. 1081 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1082 MAI->hasSetDirective()) { 1083 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1084 const TargetLowering *TLI = TM.getTargetLowering(); 1085 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1086 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1087 const MachineBasicBlock *MBB = JTBBs[ii]; 1088 if (!EmittedSets.insert(MBB)) continue; 1089 1090 // .set LJTSet, LBB32-base 1091 const MCExpr *LHS = 1092 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1093 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1094 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1095 } 1096 } 1097 1098 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1099 // before each jump table. The first label is never referenced, but tells 1100 // the assembler and linker the extents of the jump table object. The 1101 // second label is actually referenced by the code. 1102 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1103 // FIXME: This doesn't have to have any specific name, just any randomly 1104 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1105 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1106 1107 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1108 1109 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1110 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1111 } 1112 } 1113 1114 /// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1115 /// current stream. 1116 void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1117 const MachineBasicBlock *MBB, 1118 unsigned UID) const { 1119 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1120 const MCExpr *Value = 0; 1121 switch (MJTI->getEntryKind()) { 1122 case MachineJumpTableInfo::EK_Inline: 1123 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1124 case MachineJumpTableInfo::EK_Custom32: 1125 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1126 OutContext); 1127 break; 1128 case MachineJumpTableInfo::EK_BlockAddress: 1129 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1130 // .word LBB123 1131 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1132 break; 1133 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1134 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1135 // with a relocation as gp-relative, e.g.: 1136 // .gprel32 LBB123 1137 MCSymbol *MBBSym = MBB->getSymbol(); 1138 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1139 return; 1140 } 1141 1142 case MachineJumpTableInfo::EK_LabelDifference32: { 1143 // EK_LabelDifference32 - Each entry is the address of the block minus 1144 // the address of the jump table. This is used for PIC jump tables where 1145 // gprel32 is not supported. e.g.: 1146 // .word LBB123 - LJTI1_2 1147 // If the .set directive is supported, this is emitted as: 1148 // .set L4_5_set_123, LBB123 - LJTI1_2 1149 // .word L4_5_set_123 1150 1151 // If we have emitted set directives for the jump table entries, print 1152 // them rather than the entries themselves. If we're emitting PIC, then 1153 // emit the table entries as differences between two text section labels. 1154 if (MAI->hasSetDirective()) { 1155 // If we used .set, reference the .set's symbol. 1156 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1157 OutContext); 1158 break; 1159 } 1160 // Otherwise, use the difference as the jump table entry. 1161 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1162 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1163 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1164 break; 1165 } 1166 } 1167 1168 assert(Value && "Unknown entry kind!"); 1169 1170 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1171 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1172 } 1173 1174 1175 /// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1176 /// special global used by LLVM. If so, emit it and return true, otherwise 1177 /// do nothing and return false. 1178 bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1179 if (GV->getName() == "llvm.used") { 1180 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1181 EmitLLVMUsedList(GV->getInitializer()); 1182 return true; 1183 } 1184 1185 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1186 if (GV->getSection() == "llvm.metadata" || 1187 GV->hasAvailableExternallyLinkage()) 1188 return true; 1189 1190 if (!GV->hasAppendingLinkage()) return false; 1191 1192 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1193 1194 const TargetData *TD = TM.getTargetData(); 1195 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1196 if (GV->getName() == "llvm.global_ctors") { 1197 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1198 EmitAlignment(Align); 1199 EmitXXStructorList(GV->getInitializer()); 1200 1201 if (TM.getRelocationModel() == Reloc::Static && 1202 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1203 StringRef Sym(".constructors_used"); 1204 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1205 MCSA_Reference); 1206 } 1207 return true; 1208 } 1209 1210 if (GV->getName() == "llvm.global_dtors") { 1211 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1212 EmitAlignment(Align); 1213 EmitXXStructorList(GV->getInitializer()); 1214 1215 if (TM.getRelocationModel() == Reloc::Static && 1216 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1217 StringRef Sym(".destructors_used"); 1218 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1219 MCSA_Reference); 1220 } 1221 return true; 1222 } 1223 1224 return false; 1225 } 1226 1227 /// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1228 /// global in the specified llvm.used list for which emitUsedDirectiveFor 1229 /// is true, as being used with this directive. 1230 void AsmPrinter::EmitLLVMUsedList(const Constant *List) { 1231 // Should be an array of 'i8*'. 1232 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1233 if (InitList == 0) return; 1234 1235 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1236 const GlobalValue *GV = 1237 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1238 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1239 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1240 } 1241 } 1242 1243 typedef std::pair<int, Constant*> Structor; 1244 1245 static bool priority_order(const Structor& lhs, const Structor& rhs) { 1246 return lhs.first < rhs.first; 1247 } 1248 1249 /// EmitXXStructorList - Emit the ctor or dtor list taking into account the init 1250 /// priority. 1251 void AsmPrinter::EmitXXStructorList(const Constant *List) { 1252 // Should be an array of '{ int, void ()* }' structs. The first value is the 1253 // init priority. 1254 if (!isa<ConstantArray>(List)) return; 1255 1256 // Sanity check the structors list. 1257 const ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1258 if (!InitList) return; // Not an array! 1259 StructType *ETy = dyn_cast<StructType>(InitList->getType()->getElementType()); 1260 if (!ETy || ETy->getNumElements() != 2) return; // Not an array of pairs! 1261 if (!isa<IntegerType>(ETy->getTypeAtIndex(0U)) || 1262 !isa<PointerType>(ETy->getTypeAtIndex(1U))) return; // Not (int, ptr). 1263 1264 // Gather the structors in a form that's convenient for sorting by priority. 1265 SmallVector<Structor, 8> Structors; 1266 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1267 ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i)); 1268 if (!CS) continue; // Malformed. 1269 if (CS->getOperand(1)->isNullValue()) 1270 break; // Found a null terminator, skip the rest. 1271 ConstantInt *Priority = dyn_cast<ConstantInt>(CS->getOperand(0)); 1272 if (!Priority) continue; // Malformed. 1273 Structors.push_back(std::make_pair(Priority->getLimitedValue(65535), 1274 CS->getOperand(1))); 1275 } 1276 1277 // Emit the function pointers in reverse priority order. 1278 switch (MAI->getStructorOutputOrder()) { 1279 case Structors::None: 1280 break; 1281 case Structors::PriorityOrder: 1282 std::sort(Structors.begin(), Structors.end(), priority_order); 1283 break; 1284 case Structors::ReversePriorityOrder: 1285 std::sort(Structors.rbegin(), Structors.rend(), priority_order); 1286 break; 1287 } 1288 for (unsigned i = 0, e = Structors.size(); i != e; ++i) 1289 EmitGlobalConstant(Structors[i].second); 1290 } 1291 1292 //===--------------------------------------------------------------------===// 1293 // Emission and print routines 1294 // 1295 1296 /// EmitInt8 - Emit a byte directive and value. 1297 /// 1298 void AsmPrinter::EmitInt8(int Value) const { 1299 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1300 } 1301 1302 /// EmitInt16 - Emit a short directive and value. 1303 /// 1304 void AsmPrinter::EmitInt16(int Value) const { 1305 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1306 } 1307 1308 /// EmitInt32 - Emit a long directive and value. 1309 /// 1310 void AsmPrinter::EmitInt32(int Value) const { 1311 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1312 } 1313 1314 /// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1315 /// in bytes of the directive is specified by Size and Hi/Lo specify the 1316 /// labels. This implicitly uses .set if it is available. 1317 void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1318 unsigned Size) const { 1319 // Get the Hi-Lo expression. 1320 const MCExpr *Diff = 1321 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1322 MCSymbolRefExpr::Create(Lo, OutContext), 1323 OutContext); 1324 1325 if (!MAI->hasSetDirective()) { 1326 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1327 return; 1328 } 1329 1330 // Otherwise, emit with .set (aka assignment). 1331 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1332 OutStreamer.EmitAssignment(SetLabel, Diff); 1333 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1334 } 1335 1336 /// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1337 /// where the size in bytes of the directive is specified by Size and Hi/Lo 1338 /// specify the labels. This implicitly uses .set if it is available. 1339 void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1340 const MCSymbol *Lo, unsigned Size) 1341 const { 1342 1343 // Emit Hi+Offset - Lo 1344 // Get the Hi+Offset expression. 1345 const MCExpr *Plus = 1346 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1347 MCConstantExpr::Create(Offset, OutContext), 1348 OutContext); 1349 1350 // Get the Hi+Offset-Lo expression. 1351 const MCExpr *Diff = 1352 MCBinaryExpr::CreateSub(Plus, 1353 MCSymbolRefExpr::Create(Lo, OutContext), 1354 OutContext); 1355 1356 if (!MAI->hasSetDirective()) 1357 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1358 else { 1359 // Otherwise, emit with .set (aka assignment). 1360 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1361 OutStreamer.EmitAssignment(SetLabel, Diff); 1362 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1363 } 1364 } 1365 1366 /// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1367 /// where the size in bytes of the directive is specified by Size and Label 1368 /// specifies the label. This implicitly uses .set if it is available. 1369 void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1370 unsigned Size) 1371 const { 1372 1373 // Emit Label+Offset 1374 const MCExpr *Plus = 1375 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1376 MCConstantExpr::Create(Offset, OutContext), 1377 OutContext); 1378 1379 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1380 } 1381 1382 1383 //===----------------------------------------------------------------------===// 1384 1385 // EmitAlignment - Emit an alignment directive to the specified power of 1386 // two boundary. For example, if you pass in 3 here, you will get an 8 1387 // byte alignment. If a global value is specified, and if that global has 1388 // an explicit alignment requested, it will override the alignment request 1389 // if required for correctness. 1390 // 1391 void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1392 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1393 1394 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1395 1396 if (getCurrentSection()->getKind().isText()) 1397 OutStreamer.EmitCodeAlignment(1 << NumBits); 1398 else 1399 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1400 } 1401 1402 //===----------------------------------------------------------------------===// 1403 // Constant emission. 1404 //===----------------------------------------------------------------------===// 1405 1406 /// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1407 /// 1408 static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1409 MCContext &Ctx = AP.OutContext; 1410 1411 if (CV->isNullValue() || isa<UndefValue>(CV)) 1412 return MCConstantExpr::Create(0, Ctx); 1413 1414 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1415 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1416 1417 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1418 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1419 1420 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1421 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1422 1423 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1424 if (CE == 0) { 1425 llvm_unreachable("Unknown constant value to lower!"); 1426 return MCConstantExpr::Create(0, Ctx); 1427 } 1428 1429 switch (CE->getOpcode()) { 1430 default: 1431 // If the code isn't optimized, there may be outstanding folding 1432 // opportunities. Attempt to fold the expression using TargetData as a 1433 // last resort before giving up. 1434 if (Constant *C = 1435 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1436 if (C != CE) 1437 return LowerConstant(C, AP); 1438 1439 // Otherwise report the problem to the user. 1440 { 1441 std::string S; 1442 raw_string_ostream OS(S); 1443 OS << "Unsupported expression in static initializer: "; 1444 WriteAsOperand(OS, CE, /*PrintType=*/false, 1445 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1446 report_fatal_error(OS.str()); 1447 } 1448 return MCConstantExpr::Create(0, Ctx); 1449 case Instruction::GetElementPtr: { 1450 const TargetData &TD = *AP.TM.getTargetData(); 1451 // Generate a symbolic expression for the byte address 1452 const Constant *PtrVal = CE->getOperand(0); 1453 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1454 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), IdxVec); 1455 1456 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1457 if (Offset == 0) 1458 return Base; 1459 1460 // Truncate/sext the offset to the pointer size. 1461 if (TD.getPointerSizeInBits() != 64) { 1462 int SExtAmount = 64-TD.getPointerSizeInBits(); 1463 Offset = (Offset << SExtAmount) >> SExtAmount; 1464 } 1465 1466 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1467 Ctx); 1468 } 1469 1470 case Instruction::Trunc: 1471 // We emit the value and depend on the assembler to truncate the generated 1472 // expression properly. This is important for differences between 1473 // blockaddress labels. Since the two labels are in the same function, it 1474 // is reasonable to treat their delta as a 32-bit value. 1475 // FALL THROUGH. 1476 case Instruction::BitCast: 1477 return LowerConstant(CE->getOperand(0), AP); 1478 1479 case Instruction::IntToPtr: { 1480 const TargetData &TD = *AP.TM.getTargetData(); 1481 // Handle casts to pointers by changing them into casts to the appropriate 1482 // integer type. This promotes constant folding and simplifies this code. 1483 Constant *Op = CE->getOperand(0); 1484 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1485 false/*ZExt*/); 1486 return LowerConstant(Op, AP); 1487 } 1488 1489 case Instruction::PtrToInt: { 1490 const TargetData &TD = *AP.TM.getTargetData(); 1491 // Support only foldable casts to/from pointers that can be eliminated by 1492 // changing the pointer to the appropriately sized integer type. 1493 Constant *Op = CE->getOperand(0); 1494 Type *Ty = CE->getType(); 1495 1496 const MCExpr *OpExpr = LowerConstant(Op, AP); 1497 1498 // We can emit the pointer value into this slot if the slot is an 1499 // integer slot equal to the size of the pointer. 1500 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1501 return OpExpr; 1502 1503 // Otherwise the pointer is smaller than the resultant integer, mask off 1504 // the high bits so we are sure to get a proper truncation if the input is 1505 // a constant expr. 1506 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1507 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1508 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1509 } 1510 1511 // The MC library also has a right-shift operator, but it isn't consistently 1512 // signed or unsigned between different targets. 1513 case Instruction::Add: 1514 case Instruction::Sub: 1515 case Instruction::Mul: 1516 case Instruction::SDiv: 1517 case Instruction::SRem: 1518 case Instruction::Shl: 1519 case Instruction::And: 1520 case Instruction::Or: 1521 case Instruction::Xor: { 1522 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1523 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1524 switch (CE->getOpcode()) { 1525 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1526 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1527 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1528 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1529 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1530 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1531 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1532 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1533 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1534 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1535 } 1536 } 1537 } 1538 } 1539 1540 static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1541 AsmPrinter &AP); 1542 1543 /// isRepeatedByteSequence - Determine whether the given value is 1544 /// composed of a repeated sequence of identical bytes and return the 1545 /// byte value. If it is not a repeated sequence, return -1. 1546 static int isRepeatedByteSequence(const Value *V, TargetMachine &TM) { 1547 1548 if (const ConstantInt *CI = dyn_cast<ConstantInt>(V)) { 1549 if (CI->getBitWidth() > 64) return -1; 1550 1551 uint64_t Size = TM.getTargetData()->getTypeAllocSize(V->getType()); 1552 uint64_t Value = CI->getZExtValue(); 1553 1554 // Make sure the constant is at least 8 bits long and has a power 1555 // of 2 bit width. This guarantees the constant bit width is 1556 // always a multiple of 8 bits, avoiding issues with padding out 1557 // to Size and other such corner cases. 1558 if (CI->getBitWidth() < 8 || !isPowerOf2_64(CI->getBitWidth())) return -1; 1559 1560 uint8_t Byte = static_cast<uint8_t>(Value); 1561 1562 for (unsigned i = 1; i < Size; ++i) { 1563 Value >>= 8; 1564 if (static_cast<uint8_t>(Value) != Byte) return -1; 1565 } 1566 return Byte; 1567 } 1568 if (const ConstantArray *CA = dyn_cast<ConstantArray>(V)) { 1569 // Make sure all array elements are sequences of the same repeated 1570 // byte. 1571 if (CA->getNumOperands() == 0) return -1; 1572 1573 int Byte = isRepeatedByteSequence(CA->getOperand(0), TM); 1574 if (Byte == -1) return -1; 1575 1576 for (unsigned i = 1, e = CA->getNumOperands(); i != e; ++i) { 1577 int ThisByte = isRepeatedByteSequence(CA->getOperand(i), TM); 1578 if (ThisByte == -1) return -1; 1579 if (Byte != ThisByte) return -1; 1580 } 1581 return Byte; 1582 } 1583 1584 return -1; 1585 } 1586 1587 static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1588 AsmPrinter &AP) { 1589 if (AddrSpace != 0 || !CA->isString()) { 1590 // Not a string. Print the values in successive locations. 1591 1592 // See if we can aggregate some values. Make sure it can be 1593 // represented as a series of bytes of the constant value. 1594 int Value = isRepeatedByteSequence(CA, AP.TM); 1595 1596 if (Value != -1) { 1597 uint64_t Bytes = AP.TM.getTargetData()->getTypeAllocSize(CA->getType()); 1598 AP.OutStreamer.EmitFill(Bytes, Value, AddrSpace); 1599 } 1600 else { 1601 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1602 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1603 } 1604 return; 1605 } 1606 1607 // Otherwise, it can be emitted as .ascii. 1608 SmallVector<char, 128> TmpVec; 1609 TmpVec.reserve(CA->getNumOperands()); 1610 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1611 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1612 1613 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1614 } 1615 1616 static void EmitGlobalConstantVector(const ConstantVector *CV, 1617 unsigned AddrSpace, AsmPrinter &AP) { 1618 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1619 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1620 1621 const TargetData &TD = *AP.TM.getTargetData(); 1622 unsigned Size = TD.getTypeAllocSize(CV->getType()); 1623 unsigned EmittedSize = TD.getTypeAllocSize(CV->getType()->getElementType()) * 1624 CV->getType()->getNumElements(); 1625 if (unsigned Padding = Size - EmittedSize) 1626 AP.OutStreamer.EmitZeros(Padding, AddrSpace); 1627 } 1628 1629 static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1630 unsigned AddrSpace, AsmPrinter &AP) { 1631 // Print the fields in successive locations. Pad to align if needed! 1632 const TargetData *TD = AP.TM.getTargetData(); 1633 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1634 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1635 uint64_t SizeSoFar = 0; 1636 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1637 const Constant *Field = CS->getOperand(i); 1638 1639 // Check if padding is needed and insert one or more 0s. 1640 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1641 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1642 - Layout->getElementOffset(i)) - FieldSize; 1643 SizeSoFar += FieldSize + PadSize; 1644 1645 // Now print the actual field value. 1646 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1647 1648 // Insert padding - this may include padding to increase the size of the 1649 // current field up to the ABI size (if the struct is not packed) as well 1650 // as padding to ensure that the next field starts at the right offset. 1651 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1652 } 1653 assert(SizeSoFar == Layout->getSizeInBytes() && 1654 "Layout of constant struct may be incorrect!"); 1655 } 1656 1657 static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1658 AsmPrinter &AP) { 1659 // FP Constants are printed as integer constants to avoid losing 1660 // precision. 1661 if (CFP->getType()->isDoubleTy()) { 1662 if (AP.isVerbose()) { 1663 double Val = CFP->getValueAPF().convertToDouble(); 1664 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1665 } 1666 1667 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1668 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1669 return; 1670 } 1671 1672 if (CFP->getType()->isFloatTy()) { 1673 if (AP.isVerbose()) { 1674 float Val = CFP->getValueAPF().convertToFloat(); 1675 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1676 } 1677 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1678 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1679 return; 1680 } 1681 1682 if (CFP->getType()->isX86_FP80Ty()) { 1683 // all long double variants are printed as hex 1684 // API needed to prevent premature destruction 1685 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1686 const uint64_t *p = API.getRawData(); 1687 if (AP.isVerbose()) { 1688 // Convert to double so we can print the approximate val as a comment. 1689 APFloat DoubleVal = CFP->getValueAPF(); 1690 bool ignored; 1691 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1692 &ignored); 1693 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1694 << DoubleVal.convertToDouble() << '\n'; 1695 } 1696 1697 if (AP.TM.getTargetData()->isBigEndian()) { 1698 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1699 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1700 } else { 1701 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1702 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1703 } 1704 1705 // Emit the tail padding for the long double. 1706 const TargetData &TD = *AP.TM.getTargetData(); 1707 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1708 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1709 return; 1710 } 1711 1712 assert(CFP->getType()->isPPC_FP128Ty() && 1713 "Floating point constant type not handled"); 1714 // All long double variants are printed as hex 1715 // API needed to prevent premature destruction. 1716 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1717 const uint64_t *p = API.getRawData(); 1718 if (AP.TM.getTargetData()->isBigEndian()) { 1719 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1720 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1721 } else { 1722 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1723 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1724 } 1725 } 1726 1727 static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1728 unsigned AddrSpace, AsmPrinter &AP) { 1729 const TargetData *TD = AP.TM.getTargetData(); 1730 unsigned BitWidth = CI->getBitWidth(); 1731 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1732 1733 // We don't expect assemblers to support integer data directives 1734 // for more than 64 bits, so we emit the data in at most 64-bit 1735 // quantities at a time. 1736 const uint64_t *RawData = CI->getValue().getRawData(); 1737 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1738 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1739 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1740 } 1741 } 1742 1743 static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1744 AsmPrinter &AP) { 1745 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1746 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1747 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1748 } 1749 1750 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1751 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1752 switch (Size) { 1753 case 1: 1754 case 2: 1755 case 4: 1756 case 8: 1757 if (AP.isVerbose()) 1758 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1759 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1760 return; 1761 default: 1762 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1763 return; 1764 } 1765 } 1766 1767 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1768 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1769 1770 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1771 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1772 1773 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1774 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1775 1776 if (isa<ConstantPointerNull>(CV)) { 1777 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1778 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1779 return; 1780 } 1781 1782 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1783 return EmitGlobalConstantVector(V, AddrSpace, AP); 1784 1785 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1786 // thread the streamer with EmitValue. 1787 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1788 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1789 AddrSpace); 1790 } 1791 1792 /// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1793 void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1794 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1795 if (Size) 1796 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1797 else if (MAI->hasSubsectionsViaSymbols()) { 1798 // If the global has zero size, emit a single byte so that two labels don't 1799 // look like they are at the same location. 1800 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1801 } 1802 } 1803 1804 void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1805 // Target doesn't support this yet! 1806 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1807 } 1808 1809 void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1810 if (Offset > 0) 1811 OS << '+' << Offset; 1812 else if (Offset < 0) 1813 OS << Offset; 1814 } 1815 1816 //===----------------------------------------------------------------------===// 1817 // Symbol Lowering Routines. 1818 //===----------------------------------------------------------------------===// 1819 1820 /// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1821 /// temporary label with the specified stem and unique ID. 1822 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1823 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1824 Name + Twine(ID)); 1825 } 1826 1827 /// GetTempSymbol - Return an assembler temporary label with the specified 1828 /// stem. 1829 MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1830 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1831 Name); 1832 } 1833 1834 1835 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1836 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1837 } 1838 1839 MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1840 return MMI->getAddrLabelSymbol(BB); 1841 } 1842 1843 /// GetCPISymbol - Return the symbol for the specified constant pool entry. 1844 MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1845 return OutContext.GetOrCreateSymbol 1846 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1847 + "_" + Twine(CPID)); 1848 } 1849 1850 /// GetJTISymbol - Return the symbol for the specified jump table entry. 1851 MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1852 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1853 } 1854 1855 /// GetJTSetSymbol - Return the symbol for the specified jump table .set 1856 /// FIXME: privatize to AsmPrinter. 1857 MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1858 return OutContext.GetOrCreateSymbol 1859 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1860 Twine(UID) + "_set_" + Twine(MBBID)); 1861 } 1862 1863 /// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1864 /// global value name as its base, with the specified suffix, and where the 1865 /// symbol is forced to have private linkage if ForcePrivate is true. 1866 MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1867 StringRef Suffix, 1868 bool ForcePrivate) const { 1869 SmallString<60> NameStr; 1870 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1871 NameStr.append(Suffix.begin(), Suffix.end()); 1872 return OutContext.GetOrCreateSymbol(NameStr.str()); 1873 } 1874 1875 /// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1876 /// ExternalSymbol. 1877 MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1878 SmallString<60> NameStr; 1879 Mang->getNameWithPrefix(NameStr, Sym); 1880 return OutContext.GetOrCreateSymbol(NameStr.str()); 1881 } 1882 1883 1884 1885 /// PrintParentLoopComment - Print comments about parent loops of this one. 1886 static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1887 unsigned FunctionNumber) { 1888 if (Loop == 0) return; 1889 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1890 OS.indent(Loop->getLoopDepth()*2) 1891 << "Parent Loop BB" << FunctionNumber << "_" 1892 << Loop->getHeader()->getNumber() 1893 << " Depth=" << Loop->getLoopDepth() << '\n'; 1894 } 1895 1896 1897 /// PrintChildLoopComment - Print comments about child loops within 1898 /// the loop for this basic block, with nesting. 1899 static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1900 unsigned FunctionNumber) { 1901 // Add child loop information 1902 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1903 OS.indent((*CL)->getLoopDepth()*2) 1904 << "Child Loop BB" << FunctionNumber << "_" 1905 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1906 << '\n'; 1907 PrintChildLoopComment(OS, *CL, FunctionNumber); 1908 } 1909 } 1910 1911 /// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1912 static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1913 const MachineLoopInfo *LI, 1914 const AsmPrinter &AP) { 1915 // Add loop depth information 1916 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1917 if (Loop == 0) return; 1918 1919 MachineBasicBlock *Header = Loop->getHeader(); 1920 assert(Header && "No header for loop"); 1921 1922 // If this block is not a loop header, just print out what is the loop header 1923 // and return. 1924 if (Header != &MBB) { 1925 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1926 Twine(AP.getFunctionNumber())+"_" + 1927 Twine(Loop->getHeader()->getNumber())+ 1928 " Depth="+Twine(Loop->getLoopDepth())); 1929 return; 1930 } 1931 1932 // Otherwise, it is a loop header. Print out information about child and 1933 // parent loops. 1934 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1935 1936 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1937 1938 OS << "=>"; 1939 OS.indent(Loop->getLoopDepth()*2-2); 1940 1941 OS << "This "; 1942 if (Loop->empty()) 1943 OS << "Inner "; 1944 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1945 1946 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1947 } 1948 1949 1950 /// EmitBasicBlockStart - This method prints the label for the specified 1951 /// MachineBasicBlock, an alignment (if present) and a comment describing 1952 /// it if appropriate. 1953 void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1954 // Emit an alignment directive for this block, if needed. 1955 if (unsigned Align = MBB->getAlignment()) 1956 EmitAlignment(Log2_32(Align)); 1957 1958 // If the block has its address taken, emit any labels that were used to 1959 // reference the block. It is possible that there is more than one label 1960 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1961 // the references were generated. 1962 if (MBB->hasAddressTaken()) { 1963 const BasicBlock *BB = MBB->getBasicBlock(); 1964 if (isVerbose()) 1965 OutStreamer.AddComment("Block address taken"); 1966 1967 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1968 1969 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1970 OutStreamer.EmitLabel(Syms[i]); 1971 } 1972 1973 // Print the main label for the block. 1974 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1975 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1976 if (const BasicBlock *BB = MBB->getBasicBlock()) 1977 if (BB->hasName()) 1978 OutStreamer.AddComment("%" + BB->getName()); 1979 1980 EmitBasicBlockLoopComments(*MBB, LI, *this); 1981 1982 // NOTE: Want this comment at start of line, don't emit with AddComment. 1983 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1984 Twine(MBB->getNumber()) + ":"); 1985 } 1986 } else { 1987 if (isVerbose()) { 1988 if (const BasicBlock *BB = MBB->getBasicBlock()) 1989 if (BB->hasName()) 1990 OutStreamer.AddComment("%" + BB->getName()); 1991 EmitBasicBlockLoopComments(*MBB, LI, *this); 1992 } 1993 1994 OutStreamer.EmitLabel(MBB->getSymbol()); 1995 } 1996 } 1997 1998 void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 1999 bool IsDefinition) const { 2000 MCSymbolAttr Attr = MCSA_Invalid; 2001 2002 switch (Visibility) { 2003 default: break; 2004 case GlobalValue::HiddenVisibility: 2005 if (IsDefinition) 2006 Attr = MAI->getHiddenVisibilityAttr(); 2007 else 2008 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 2009 break; 2010 case GlobalValue::ProtectedVisibility: 2011 Attr = MAI->getProtectedVisibilityAttr(); 2012 break; 2013 } 2014 2015 if (Attr != MCSA_Invalid) 2016 OutStreamer.EmitSymbolAttribute(Sym, Attr); 2017 } 2018 2019 /// isBlockOnlyReachableByFallthough - Return true if the basic block has 2020 /// exactly one predecessor and the control transfer mechanism between 2021 /// the predecessor and this block is a fall-through. 2022 bool AsmPrinter:: 2023 isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 2024 // If this is a landing pad, it isn't a fall through. If it has no preds, 2025 // then nothing falls through to it. 2026 if (MBB->isLandingPad() || MBB->pred_empty()) 2027 return false; 2028 2029 // If there isn't exactly one predecessor, it can't be a fall through. 2030 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 2031 ++PI2; 2032 if (PI2 != MBB->pred_end()) 2033 return false; 2034 2035 // The predecessor has to be immediately before this block. 2036 MachineBasicBlock *Pred = *PI; 2037 2038 if (!Pred->isLayoutSuccessor(MBB)) 2039 return false; 2040 2041 // If the block is completely empty, then it definitely does fall through. 2042 if (Pred->empty()) 2043 return true; 2044 2045 // Check the terminators in the previous blocks 2046 for (MachineBasicBlock::iterator II = Pred->getFirstTerminator(), 2047 IE = Pred->end(); II != IE; ++II) { 2048 MachineInstr &MI = *II; 2049 2050 // If it is not a simple branch, we are in a table somewhere. 2051 if (!MI.getDesc().isBranch() || MI.getDesc().isIndirectBranch()) 2052 return false; 2053 2054 // If we are the operands of one of the branches, this is not 2055 // a fall through. 2056 for (MachineInstr::mop_iterator OI = MI.operands_begin(), 2057 OE = MI.operands_end(); OI != OE; ++OI) { 2058 const MachineOperand& OP = *OI; 2059 if (OP.isJTI()) 2060 return false; 2061 if (OP.isMBB() && OP.getMBB() == MBB) 2062 return false; 2063 } 2064 } 2065 2066 return true; 2067 } 2068 2069 2070 2071 GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 2072 if (!S->usesMetadata()) 2073 return 0; 2074 2075 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 2076 gcp_map_type::iterator GCPI = GCMap.find(S); 2077 if (GCPI != GCMap.end()) 2078 return GCPI->second; 2079 2080 const char *Name = S->getName().c_str(); 2081 2082 for (GCMetadataPrinterRegistry::iterator 2083 I = GCMetadataPrinterRegistry::begin(), 2084 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 2085 if (strcmp(Name, I->getName()) == 0) { 2086 GCMetadataPrinter *GMP = I->instantiate(); 2087 GMP->S = S; 2088 GCMap.insert(std::make_pair(S, GMP)); 2089 return GMP; 2090 } 2091 2092 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 2093 return 0; 2094 } 2095 2096