AsmPrinter.cpp revision 3f3bf9387b75f4c932e4c59bd7af719d26ae4b99
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/TargetAsmInfo.h" 37#include "llvm/Target/TargetData.h" 38#include "llvm/Target/TargetInstrInfo.h" 39#include "llvm/Target/TargetLowering.h" 40#include "llvm/Target/TargetLoweringObjectFile.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/Timer.h" 48using namespace llvm; 49 50static const char *DWARFGroupName = "DWARF Emission"; 51static const char *DbgTimerName = "DWARF Debug Writer"; 52static const char *EHTimerName = "DWARF Exception Writer"; 53 54STATISTIC(EmittedInsts, "Number of machine instrs printed"); 55 56char AsmPrinter::ID = 0; 57 58typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 59static gcp_map_type &getGCMap(void *&P) { 60 if (P == 0) 61 P = new gcp_map_type(); 62 return *(gcp_map_type*)P; 63} 64 65 66/// getGVAlignmentLog2 - Return the alignment to use for the specified global 67/// value in log2 form. This rounds up to the preferred alignment if possible 68/// and legal. 69static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 70 unsigned InBits = 0) { 71 unsigned NumBits = 0; 72 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 73 NumBits = TD.getPreferredAlignmentLog(GVar); 74 75 // If InBits is specified, round it to it. 76 if (InBits > NumBits) 77 NumBits = InBits; 78 79 // If the GV has a specified alignment, take it into account. 80 if (GV->getAlignment() == 0) 81 return NumBits; 82 83 unsigned GVAlign = Log2_32(GV->getAlignment()); 84 85 // If the GVAlign is larger than NumBits, or if we are required to obey 86 // NumBits because the GV has an assigned section, obey it. 87 if (GVAlign > NumBits || GV->hasSection()) 88 NumBits = GVAlign; 89 return NumBits; 90} 91 92 93 94 95AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 96 : MachineFunctionPass(ID), 97 TM(tm), MAI(tm.getMCAsmInfo()), 98 OutContext(Streamer.getContext()), 99 OutStreamer(Streamer), 100 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 101 DD = 0; DE = 0; MMI = 0; LI = 0; 102 GCMetadataPrinters = 0; 103 VerboseAsm = Streamer.isVerboseAsm(); 104} 105 106AsmPrinter::~AsmPrinter() { 107 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 108 109 if (GCMetadataPrinters != 0) { 110 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 111 112 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 113 delete I->second; 114 delete &GCMap; 115 GCMetadataPrinters = 0; 116 } 117 118 delete &OutStreamer; 119} 120 121/// getFunctionNumber - Return a unique ID for the current function. 122/// 123unsigned AsmPrinter::getFunctionNumber() const { 124 return MF->getFunctionNumber(); 125} 126 127const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 128 return TM.getTargetLowering()->getObjFileLowering(); 129} 130 131 132/// getTargetData - Return information about data layout. 133const TargetData &AsmPrinter::getTargetData() const { 134 return *TM.getTargetData(); 135} 136 137/// getCurrentSection() - Return the current section we are emitting to. 138const MCSection *AsmPrinter::getCurrentSection() const { 139 return OutStreamer.getCurrentSection(); 140} 141 142 143 144void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 145 AU.setPreservesAll(); 146 MachineFunctionPass::getAnalysisUsage(AU); 147 AU.addRequired<MachineModuleInfo>(); 148 AU.addRequired<GCModuleInfo>(); 149 if (isVerbose()) 150 AU.addRequired<MachineLoopInfo>(); 151} 152 153bool AsmPrinter::doInitialization(Module &M) { 154 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 155 MMI->AnalyzeModule(M); 156 157 // Initialize TargetLoweringObjectFile. 158 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 159 .Initialize(OutContext, TM); 160 161 Mang = new Mangler(OutContext, *TM.getTargetData()); 162 163 // Allow the target to emit any magic that it wants at the start of the file. 164 EmitStartOfAsmFile(M); 165 166 // Very minimal debug info. It is ignored if we emit actual debug info. If we 167 // don't, this at least helps the user find where a global came from. 168 if (MAI->hasSingleParameterDotFile()) { 169 // .file "foo.c" 170 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 171 } 172 173 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 174 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 175 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 176 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 177 MP->beginAssembly(*this); 178 179 // Emit module-level inline asm if it exists. 180 if (!M.getModuleInlineAsm().empty()) { 181 OutStreamer.AddComment("Start of file scope inline assembly"); 182 OutStreamer.AddBlankLine(); 183 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 184 OutStreamer.AddComment("End of file scope inline assembly"); 185 OutStreamer.AddBlankLine(); 186 } 187 188 if (MAI->doesSupportDebugInformation()) 189 DD = new DwarfDebug(this, &M); 190 191 if (MAI->doesSupportExceptionHandling()) 192 switch (MAI->getExceptionHandlingType()) { 193 default: 194 case ExceptionHandling::DwarfTable: 195 DE = new DwarfTableException(this); 196 break; 197 case ExceptionHandling::DwarfCFI: 198 DE = new DwarfCFIException(this); 199 break; 200 case ExceptionHandling::ARM: 201 DE = new ARMException(this); 202 break; 203 } 204 205 return false; 206} 207 208void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 209 switch ((GlobalValue::LinkageTypes)Linkage) { 210 case GlobalValue::CommonLinkage: 211 case GlobalValue::LinkOnceAnyLinkage: 212 case GlobalValue::LinkOnceODRLinkage: 213 case GlobalValue::WeakAnyLinkage: 214 case GlobalValue::WeakODRLinkage: 215 case GlobalValue::LinkerPrivateWeakLinkage: 216 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 217 if (MAI->getWeakDefDirective() != 0) { 218 // .globl _foo 219 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 220 221 if ((GlobalValue::LinkageTypes)Linkage != 222 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 223 // .weak_definition _foo 224 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 225 else 226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 227 } else if (MAI->getLinkOnceDirective() != 0) { 228 // .globl _foo 229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 230 //NOTE: linkonce is handled by the section the symbol was assigned to. 231 } else { 232 // .weak _foo 233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 234 } 235 break; 236 case GlobalValue::DLLExportLinkage: 237 case GlobalValue::AppendingLinkage: 238 // FIXME: appending linkage variables should go into a section of 239 // their name or something. For now, just emit them as external. 240 case GlobalValue::ExternalLinkage: 241 // If external or appending, declare as a global symbol. 242 // .globl _foo 243 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 244 break; 245 case GlobalValue::PrivateLinkage: 246 case GlobalValue::InternalLinkage: 247 case GlobalValue::LinkerPrivateLinkage: 248 break; 249 default: 250 llvm_unreachable("Unknown linkage type!"); 251 } 252} 253 254 255/// EmitGlobalVariable - Emit the specified global variable to the .s file. 256void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 257 if (GV->hasInitializer()) { 258 // Check to see if this is a special global used by LLVM, if so, emit it. 259 if (EmitSpecialLLVMGlobal(GV)) 260 return; 261 262 if (isVerbose()) { 263 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 264 /*PrintType=*/false, GV->getParent()); 265 OutStreamer.GetCommentOS() << '\n'; 266 } 267 } 268 269 MCSymbol *GVSym = Mang->getSymbol(GV); 270 EmitVisibility(GVSym, GV->getVisibility()); 271 272 if (!GV->hasInitializer()) // External globals require no extra code. 273 return; 274 275 if (MAI->hasDotTypeDotSizeDirective()) 276 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 277 278 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 279 280 const TargetData *TD = TM.getTargetData(); 281 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 282 283 // If the alignment is specified, we *must* obey it. Overaligning a global 284 // with a specified alignment is a prompt way to break globals emitted to 285 // sections and expected to be contiguous (e.g. ObjC metadata). 286 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 287 288 // Handle common and BSS local symbols (.lcomm). 289 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 290 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 291 292 if (isVerbose()) { 293 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 294 /*PrintType=*/false, GV->getParent()); 295 OutStreamer.GetCommentOS() << '\n'; 296 } 297 298 // Handle common symbols. 299 if (GVKind.isCommon()) { 300 unsigned Align = 1 << AlignLog; 301 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 302 Align = 0; 303 304 // .comm _foo, 42, 4 305 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 306 return; 307 } 308 309 // Handle local BSS symbols. 310 if (MAI->hasMachoZeroFillDirective()) { 311 const MCSection *TheSection = 312 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 313 // .zerofill __DATA, __bss, _foo, 400, 5 314 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 315 return; 316 } 317 318 if (MAI->hasLCOMMDirective()) { 319 // .lcomm _foo, 42 320 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 321 return; 322 } 323 324 unsigned Align = 1 << AlignLog; 325 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 326 Align = 0; 327 328 // .local _foo 329 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 330 // .comm _foo, 42, 4 331 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 332 return; 333 } 334 335 const MCSection *TheSection = 336 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 337 338 // Handle the zerofill directive on darwin, which is a special form of BSS 339 // emission. 340 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 341 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 342 343 // .globl _foo 344 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 345 // .zerofill __DATA, __common, _foo, 400, 5 346 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 347 return; 348 } 349 350 // Handle thread local data for mach-o which requires us to output an 351 // additional structure of data and mangle the original symbol so that we 352 // can reference it later. 353 // 354 // TODO: This should become an "emit thread local global" method on TLOF. 355 // All of this macho specific stuff should be sunk down into TLOFMachO and 356 // stuff like "TLSExtraDataSection" should no longer be part of the parent 357 // TLOF class. This will also make it more obvious that stuff like 358 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 359 // specific code. 360 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 361 // Emit the .tbss symbol 362 MCSymbol *MangSym = 363 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 364 365 if (GVKind.isThreadBSS()) 366 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 367 else if (GVKind.isThreadData()) { 368 OutStreamer.SwitchSection(TheSection); 369 370 EmitAlignment(AlignLog, GV); 371 OutStreamer.EmitLabel(MangSym); 372 373 EmitGlobalConstant(GV->getInitializer()); 374 } 375 376 OutStreamer.AddBlankLine(); 377 378 // Emit the variable struct for the runtime. 379 const MCSection *TLVSect 380 = getObjFileLowering().getTLSExtraDataSection(); 381 382 OutStreamer.SwitchSection(TLVSect); 383 // Emit the linkage here. 384 EmitLinkage(GV->getLinkage(), GVSym); 385 OutStreamer.EmitLabel(GVSym); 386 387 // Three pointers in size: 388 // - __tlv_bootstrap - used to make sure support exists 389 // - spare pointer, used when mapped by the runtime 390 // - pointer to mangled symbol above with initializer 391 unsigned PtrSize = TD->getPointerSizeInBits()/8; 392 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 393 PtrSize, 0); 394 OutStreamer.EmitIntValue(0, PtrSize, 0); 395 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 396 397 OutStreamer.AddBlankLine(); 398 return; 399 } 400 401 OutStreamer.SwitchSection(TheSection); 402 403 EmitLinkage(GV->getLinkage(), GVSym); 404 EmitAlignment(AlignLog, GV); 405 406 OutStreamer.EmitLabel(GVSym); 407 408 EmitGlobalConstant(GV->getInitializer()); 409 410 if (MAI->hasDotTypeDotSizeDirective()) 411 // .size foo, 42 412 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 413 414 OutStreamer.AddBlankLine(); 415} 416 417/// EmitFunctionHeader - This method emits the header for the current 418/// function. 419void AsmPrinter::EmitFunctionHeader() { 420 // Print out constants referenced by the function 421 EmitConstantPool(); 422 423 // Print the 'header' of function. 424 const Function *F = MF->getFunction(); 425 426 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 427 EmitVisibility(CurrentFnSym, F->getVisibility()); 428 429 EmitLinkage(F->getLinkage(), CurrentFnSym); 430 EmitAlignment(MF->getAlignment(), F); 431 432 if (MAI->hasDotTypeDotSizeDirective()) 433 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 434 435 if (isVerbose()) { 436 WriteAsOperand(OutStreamer.GetCommentOS(), F, 437 /*PrintType=*/false, F->getParent()); 438 OutStreamer.GetCommentOS() << '\n'; 439 } 440 441 // Emit the CurrentFnSym. This is a virtual function to allow targets to 442 // do their wild and crazy things as required. 443 EmitFunctionEntryLabel(); 444 445 // If the function had address-taken blocks that got deleted, then we have 446 // references to the dangling symbols. Emit them at the start of the function 447 // so that we don't get references to undefined symbols. 448 std::vector<MCSymbol*> DeadBlockSyms; 449 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 450 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 451 OutStreamer.AddComment("Address taken block that was later removed"); 452 OutStreamer.EmitLabel(DeadBlockSyms[i]); 453 } 454 455 // Add some workaround for linkonce linkage on Cygwin\MinGW. 456 if (MAI->getLinkOnceDirective() != 0 && 457 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 458 // FIXME: What is this? 459 MCSymbol *FakeStub = 460 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 461 CurrentFnSym->getName()); 462 OutStreamer.EmitLabel(FakeStub); 463 } 464 465 // Emit pre-function debug and/or EH information. 466 if (DE) { 467 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 468 DE->BeginFunction(MF); 469 } 470 if (DD) { 471 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 472 DD->beginFunction(MF); 473 } 474} 475 476/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 477/// function. This can be overridden by targets as required to do custom stuff. 478void AsmPrinter::EmitFunctionEntryLabel() { 479 // The function label could have already been emitted if two symbols end up 480 // conflicting due to asm renaming. Detect this and emit an error. 481 if (CurrentFnSym->isUndefined()) 482 return OutStreamer.EmitLabel(CurrentFnSym); 483 484 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 485 "' label emitted multiple times to assembly file"); 486} 487 488 489/// EmitComments - Pretty-print comments for instructions. 490static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 491 const MachineFunction *MF = MI.getParent()->getParent(); 492 const TargetMachine &TM = MF->getTarget(); 493 494 // Check for spills and reloads 495 int FI; 496 497 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 498 499 // We assume a single instruction only has a spill or reload, not 500 // both. 501 const MachineMemOperand *MMO; 502 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 503 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 504 MMO = *MI.memoperands_begin(); 505 CommentOS << MMO->getSize() << "-byte Reload\n"; 506 } 507 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 508 if (FrameInfo->isSpillSlotObjectIndex(FI)) 509 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 510 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 511 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 512 MMO = *MI.memoperands_begin(); 513 CommentOS << MMO->getSize() << "-byte Spill\n"; 514 } 515 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 516 if (FrameInfo->isSpillSlotObjectIndex(FI)) 517 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 518 } 519 520 // Check for spill-induced copies 521 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 522 CommentOS << " Reload Reuse\n"; 523} 524 525/// EmitImplicitDef - This method emits the specified machine instruction 526/// that is an implicit def. 527static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 528 unsigned RegNo = MI->getOperand(0).getReg(); 529 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 530 AP.TM.getRegisterInfo()->getName(RegNo)); 531 AP.OutStreamer.AddBlankLine(); 532} 533 534static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 535 std::string Str = "kill:"; 536 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 537 const MachineOperand &Op = MI->getOperand(i); 538 assert(Op.isReg() && "KILL instruction must have only register operands"); 539 Str += ' '; 540 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 541 Str += (Op.isDef() ? "<def>" : "<kill>"); 542 } 543 AP.OutStreamer.AddComment(Str); 544 AP.OutStreamer.AddBlankLine(); 545} 546 547/// EmitDebugValueComment - This method handles the target-independent form 548/// of DBG_VALUE, returning true if it was able to do so. A false return 549/// means the target will need to handle MI in EmitInstruction. 550static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 551 // This code handles only the 3-operand target-independent form. 552 if (MI->getNumOperands() != 3) 553 return false; 554 555 SmallString<128> Str; 556 raw_svector_ostream OS(Str); 557 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 558 559 // cast away const; DIetc do not take const operands for some reason. 560 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 561 if (V.getContext().isSubprogram()) 562 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 563 OS << V.getName() << " <- "; 564 565 // Register or immediate value. Register 0 means undef. 566 if (MI->getOperand(0).isFPImm()) { 567 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 568 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 569 OS << (double)APF.convertToFloat(); 570 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 571 OS << APF.convertToDouble(); 572 } else { 573 // There is no good way to print long double. Convert a copy to 574 // double. Ah well, it's only a comment. 575 bool ignored; 576 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 577 &ignored); 578 OS << "(long double) " << APF.convertToDouble(); 579 } 580 } else if (MI->getOperand(0).isImm()) { 581 OS << MI->getOperand(0).getImm(); 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 600void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 601 MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 602 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) { 603 OutStreamer.EmitLabel(Label); 604 return; 605 } 606 607 const MachineFunction &MF = *MI.getParent()->getParent(); 608 MachineModuleInfo &MMI = MF.getMMI(); 609 std::vector<MachineMove> &Moves = MMI.getFrameMoves(); 610 const MachineMove *Move = NULL; 611 for (std::vector<MachineMove>::iterator I = Moves.begin(), 612 E = Moves.end(); I != E; ++I) { 613 if (I->getLabel() == Label) { 614 Move = &*I; 615 break; 616 } 617 } 618 assert(Move); 619 EmitCFIFrameMove(*Move); 620} 621 622/// EmitFunctionBody - This method emits the body and trailer for a 623/// function. 624void AsmPrinter::EmitFunctionBody() { 625 // Emit target-specific gunk before the function body. 626 EmitFunctionBodyStart(); 627 628 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 629 630 // Print out code for the function. 631 bool HasAnyRealCode = false; 632 const MachineInstr *LastMI = 0; 633 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 634 I != E; ++I) { 635 // Print a label for the basic block. 636 EmitBasicBlockStart(I); 637 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 638 II != IE; ++II) { 639 LastMI = II; 640 641 // Print the assembly for the instruction. 642 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 643 !II->isDebugValue()) { 644 HasAnyRealCode = true; 645 ++EmittedInsts; 646 } 647 648 if (ShouldPrintDebugScopes) { 649 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 650 DD->beginInstruction(II); 651 } 652 653 if (isVerbose()) 654 EmitComments(*II, OutStreamer.GetCommentOS()); 655 656 switch (II->getOpcode()) { 657 case TargetOpcode::PROLOG_LABEL: 658 emitPrologLabel(*II); 659 break; 660 661 case TargetOpcode::EH_LABEL: 662 case TargetOpcode::GC_LABEL: 663 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 664 break; 665 case TargetOpcode::INLINEASM: 666 EmitInlineAsm(II); 667 break; 668 case TargetOpcode::DBG_VALUE: 669 if (isVerbose()) { 670 if (!EmitDebugValueComment(II, *this)) 671 EmitInstruction(II); 672 } 673 break; 674 case TargetOpcode::IMPLICIT_DEF: 675 if (isVerbose()) EmitImplicitDef(II, *this); 676 break; 677 case TargetOpcode::KILL: 678 if (isVerbose()) EmitKill(II, *this); 679 break; 680 default: 681 EmitInstruction(II); 682 break; 683 } 684 685 if (ShouldPrintDebugScopes) { 686 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 687 DD->endInstruction(II); 688 } 689 } 690 } 691 692 // If the last instruction was a prolog label, then we have a situation where 693 // we emitted a prolog but no function body. This results in the ending prolog 694 // label equaling the end of function label and an invalid "row" in the 695 // FDE. We need to emit a noop in this situation so that the FDE's rows are 696 // valid. 697 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 698 699 // If the function is empty and the object file uses .subsections_via_symbols, 700 // then we need to emit *something* to the function body to prevent the 701 // labels from collapsing together. Just emit a noop. 702 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 703 MCInst Noop; 704 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 705 if (Noop.getOpcode()) { 706 OutStreamer.AddComment("avoids zero-length function"); 707 OutStreamer.EmitInstruction(Noop); 708 } else // Target not mc-ized yet. 709 OutStreamer.EmitRawText(StringRef("\tnop\n")); 710 } 711 712 // Emit target-specific gunk after the function body. 713 EmitFunctionBodyEnd(); 714 715 // If the target wants a .size directive for the size of the function, emit 716 // it. 717 if (MAI->hasDotTypeDotSizeDirective()) { 718 // Create a symbol for the end of function, so we can get the size as 719 // difference between the function label and the temp label. 720 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 721 OutStreamer.EmitLabel(FnEndLabel); 722 723 const MCExpr *SizeExp = 724 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 725 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 726 OutContext); 727 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 728 } 729 730 // Emit post-function debug information. 731 if (DD) { 732 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 733 DD->endFunction(MF); 734 } 735 if (DE) { 736 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 737 DE->EndFunction(); 738 } 739 MMI->EndFunction(); 740 741 // Print out jump tables referenced by the function. 742 EmitJumpTableInfo(); 743 744 OutStreamer.AddBlankLine(); 745} 746 747/// getDebugValueLocation - Get location information encoded by DBG_VALUE 748/// operands. 749MachineLocation AsmPrinter:: 750getDebugValueLocation(const MachineInstr *MI) const { 751 // Target specific DBG_VALUE instructions are handled by each target. 752 return MachineLocation(); 753} 754 755bool AsmPrinter::doFinalization(Module &M) { 756 // Emit global variables. 757 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 758 I != E; ++I) 759 EmitGlobalVariable(I); 760 761 // Emit visibility info for declarations 762 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 763 const Function &F = *I; 764 if (!F.isDeclaration()) 765 continue; 766 GlobalValue::VisibilityTypes V = F.getVisibility(); 767 if (V == GlobalValue::DefaultVisibility) 768 continue; 769 770 MCSymbol *Name = Mang->getSymbol(&F); 771 EmitVisibility(Name, V, false); 772 } 773 774 // Finalize debug and EH information. 775 if (DE) { 776 { 777 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 778 DE->EndModule(); 779 } 780 delete DE; DE = 0; 781 } 782 if (DD) { 783 { 784 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 785 DD->endModule(); 786 } 787 delete DD; DD = 0; 788 } 789 790 // If the target wants to know about weak references, print them all. 791 if (MAI->getWeakRefDirective()) { 792 // FIXME: This is not lazy, it would be nice to only print weak references 793 // to stuff that is actually used. Note that doing so would require targets 794 // to notice uses in operands (due to constant exprs etc). This should 795 // happen with the MC stuff eventually. 796 797 // Print out module-level global variables here. 798 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 799 I != E; ++I) { 800 if (!I->hasExternalWeakLinkage()) continue; 801 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 802 } 803 804 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 805 if (!I->hasExternalWeakLinkage()) continue; 806 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 807 } 808 } 809 810 if (MAI->hasSetDirective()) { 811 OutStreamer.AddBlankLine(); 812 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 813 I != E; ++I) { 814 MCSymbol *Name = Mang->getSymbol(I); 815 816 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 817 MCSymbol *Target = Mang->getSymbol(GV); 818 819 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 820 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 821 else if (I->hasWeakLinkage()) 822 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 823 else 824 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 825 826 EmitVisibility(Name, I->getVisibility()); 827 828 // Emit the directives as assignments aka .set: 829 OutStreamer.EmitAssignment(Name, 830 MCSymbolRefExpr::Create(Target, OutContext)); 831 } 832 } 833 834 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 835 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 836 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 837 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 838 MP->finishAssembly(*this); 839 840 // If we don't have any trampolines, then we don't require stack memory 841 // to be executable. Some targets have a directive to declare this. 842 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 843 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 844 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 845 OutStreamer.SwitchSection(S); 846 847 // Allow the target to emit any magic that it wants at the end of the file, 848 // after everything else has gone out. 849 EmitEndOfAsmFile(M); 850 851 delete Mang; Mang = 0; 852 MMI = 0; 853 854 OutStreamer.Finish(); 855 return false; 856} 857 858void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 859 this->MF = &MF; 860 // Get the function symbol. 861 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 862 863 if (isVerbose()) 864 LI = &getAnalysis<MachineLoopInfo>(); 865} 866 867namespace { 868 // SectionCPs - Keep track the alignment, constpool entries per Section. 869 struct SectionCPs { 870 const MCSection *S; 871 unsigned Alignment; 872 SmallVector<unsigned, 4> CPEs; 873 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 874 }; 875} 876 877/// EmitConstantPool - Print to the current output stream assembly 878/// representations of the constants in the constant pool MCP. This is 879/// used to print out constants which have been "spilled to memory" by 880/// the code generator. 881/// 882void AsmPrinter::EmitConstantPool() { 883 const MachineConstantPool *MCP = MF->getConstantPool(); 884 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 885 if (CP.empty()) return; 886 887 // Calculate sections for constant pool entries. We collect entries to go into 888 // the same section together to reduce amount of section switch statements. 889 SmallVector<SectionCPs, 4> CPSections; 890 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 891 const MachineConstantPoolEntry &CPE = CP[i]; 892 unsigned Align = CPE.getAlignment(); 893 894 SectionKind Kind; 895 switch (CPE.getRelocationInfo()) { 896 default: llvm_unreachable("Unknown section kind"); 897 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 898 case 1: 899 Kind = SectionKind::getReadOnlyWithRelLocal(); 900 break; 901 case 0: 902 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 903 case 4: Kind = SectionKind::getMergeableConst4(); break; 904 case 8: Kind = SectionKind::getMergeableConst8(); break; 905 case 16: Kind = SectionKind::getMergeableConst16();break; 906 default: Kind = SectionKind::getMergeableConst(); break; 907 } 908 } 909 910 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 911 912 // The number of sections are small, just do a linear search from the 913 // last section to the first. 914 bool Found = false; 915 unsigned SecIdx = CPSections.size(); 916 while (SecIdx != 0) { 917 if (CPSections[--SecIdx].S == S) { 918 Found = true; 919 break; 920 } 921 } 922 if (!Found) { 923 SecIdx = CPSections.size(); 924 CPSections.push_back(SectionCPs(S, Align)); 925 } 926 927 if (Align > CPSections[SecIdx].Alignment) 928 CPSections[SecIdx].Alignment = Align; 929 CPSections[SecIdx].CPEs.push_back(i); 930 } 931 932 // Now print stuff into the calculated sections. 933 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 934 OutStreamer.SwitchSection(CPSections[i].S); 935 EmitAlignment(Log2_32(CPSections[i].Alignment)); 936 937 unsigned Offset = 0; 938 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 939 unsigned CPI = CPSections[i].CPEs[j]; 940 MachineConstantPoolEntry CPE = CP[CPI]; 941 942 // Emit inter-object padding for alignment. 943 unsigned AlignMask = CPE.getAlignment() - 1; 944 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 945 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 946 947 const Type *Ty = CPE.getType(); 948 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 949 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 950 951 if (CPE.isMachineConstantPoolEntry()) 952 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 953 else 954 EmitGlobalConstant(CPE.Val.ConstVal); 955 } 956 } 957} 958 959/// EmitJumpTableInfo - Print assembly representations of the jump tables used 960/// by the current function to the current output stream. 961/// 962void AsmPrinter::EmitJumpTableInfo() { 963 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 964 if (MJTI == 0) return; 965 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 966 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 967 if (JT.empty()) return; 968 969 // Pick the directive to use to print the jump table entries, and switch to 970 // the appropriate section. 971 const Function *F = MF->getFunction(); 972 bool JTInDiffSection = false; 973 if (// In PIC mode, we need to emit the jump table to the same section as the 974 // function body itself, otherwise the label differences won't make sense. 975 // FIXME: Need a better predicate for this: what about custom entries? 976 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 977 // We should also do if the section name is NULL or function is declared 978 // in discardable section 979 // FIXME: this isn't the right predicate, should be based on the MCSection 980 // for the function. 981 F->isWeakForLinker()) { 982 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 983 } else { 984 // Otherwise, drop it in the readonly section. 985 const MCSection *ReadOnlySection = 986 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 987 OutStreamer.SwitchSection(ReadOnlySection); 988 JTInDiffSection = true; 989 } 990 991 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 992 993 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 994 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 995 996 // If this jump table was deleted, ignore it. 997 if (JTBBs.empty()) continue; 998 999 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1000 // .set directive for each unique entry. This reduces the number of 1001 // relocations the assembler will generate for the jump table. 1002 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1003 MAI->hasSetDirective()) { 1004 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1005 const TargetLowering *TLI = TM.getTargetLowering(); 1006 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1007 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1008 const MachineBasicBlock *MBB = JTBBs[ii]; 1009 if (!EmittedSets.insert(MBB)) continue; 1010 1011 // .set LJTSet, LBB32-base 1012 const MCExpr *LHS = 1013 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1014 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1015 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1016 } 1017 } 1018 1019 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1020 // before each jump table. The first label is never referenced, but tells 1021 // the assembler and linker the extents of the jump table object. The 1022 // second label is actually referenced by the code. 1023 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1024 // FIXME: This doesn't have to have any specific name, just any randomly 1025 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1026 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1027 1028 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1029 1030 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1031 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1032 } 1033} 1034 1035/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1036/// current stream. 1037void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1038 const MachineBasicBlock *MBB, 1039 unsigned UID) const { 1040 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1041 const MCExpr *Value = 0; 1042 switch (MJTI->getEntryKind()) { 1043 case MachineJumpTableInfo::EK_Inline: 1044 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1045 case MachineJumpTableInfo::EK_Custom32: 1046 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1047 OutContext); 1048 break; 1049 case MachineJumpTableInfo::EK_BlockAddress: 1050 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1051 // .word LBB123 1052 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1053 break; 1054 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1055 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1056 // with a relocation as gp-relative, e.g.: 1057 // .gprel32 LBB123 1058 MCSymbol *MBBSym = MBB->getSymbol(); 1059 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1060 return; 1061 } 1062 1063 case MachineJumpTableInfo::EK_LabelDifference32: { 1064 // EK_LabelDifference32 - Each entry is the address of the block minus 1065 // the address of the jump table. This is used for PIC jump tables where 1066 // gprel32 is not supported. e.g.: 1067 // .word LBB123 - LJTI1_2 1068 // If the .set directive is supported, this is emitted as: 1069 // .set L4_5_set_123, LBB123 - LJTI1_2 1070 // .word L4_5_set_123 1071 1072 // If we have emitted set directives for the jump table entries, print 1073 // them rather than the entries themselves. If we're emitting PIC, then 1074 // emit the table entries as differences between two text section labels. 1075 if (MAI->hasSetDirective()) { 1076 // If we used .set, reference the .set's symbol. 1077 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1078 OutContext); 1079 break; 1080 } 1081 // Otherwise, use the difference as the jump table entry. 1082 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1083 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1084 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1085 break; 1086 } 1087 } 1088 1089 assert(Value && "Unknown entry kind!"); 1090 1091 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1092 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1093} 1094 1095 1096/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1097/// special global used by LLVM. If so, emit it and return true, otherwise 1098/// do nothing and return false. 1099bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1100 if (GV->getName() == "llvm.used") { 1101 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1102 EmitLLVMUsedList(GV->getInitializer()); 1103 return true; 1104 } 1105 1106 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1107 if (GV->getSection() == "llvm.metadata" || 1108 GV->hasAvailableExternallyLinkage()) 1109 return true; 1110 1111 if (!GV->hasAppendingLinkage()) return false; 1112 1113 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1114 1115 const TargetData *TD = TM.getTargetData(); 1116 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1117 if (GV->getName() == "llvm.global_ctors") { 1118 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1119 EmitAlignment(Align); 1120 EmitXXStructorList(GV->getInitializer()); 1121 1122 if (TM.getRelocationModel() == Reloc::Static && 1123 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1124 StringRef Sym(".constructors_used"); 1125 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1126 MCSA_Reference); 1127 } 1128 return true; 1129 } 1130 1131 if (GV->getName() == "llvm.global_dtors") { 1132 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1133 EmitAlignment(Align); 1134 EmitXXStructorList(GV->getInitializer()); 1135 1136 if (TM.getRelocationModel() == Reloc::Static && 1137 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1138 StringRef Sym(".destructors_used"); 1139 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1140 MCSA_Reference); 1141 } 1142 return true; 1143 } 1144 1145 return false; 1146} 1147 1148/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1149/// global in the specified llvm.used list for which emitUsedDirectiveFor 1150/// is true, as being used with this directive. 1151void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1152 // Should be an array of 'i8*'. 1153 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1154 if (InitList == 0) return; 1155 1156 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1157 const GlobalValue *GV = 1158 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1159 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1160 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1161 } 1162} 1163 1164/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1165/// function pointers, ignoring the init priority. 1166void AsmPrinter::EmitXXStructorList(Constant *List) { 1167 // Should be an array of '{ int, void ()* }' structs. The first value is the 1168 // init priority, which we ignore. 1169 if (!isa<ConstantArray>(List)) return; 1170 ConstantArray *InitList = cast<ConstantArray>(List); 1171 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1172 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1173 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1174 1175 if (CS->getOperand(1)->isNullValue()) 1176 return; // Found a null terminator, exit printing. 1177 // Emit the function pointer. 1178 EmitGlobalConstant(CS->getOperand(1)); 1179 } 1180} 1181 1182//===--------------------------------------------------------------------===// 1183// Emission and print routines 1184// 1185 1186/// EmitInt8 - Emit a byte directive and value. 1187/// 1188void AsmPrinter::EmitInt8(int Value) const { 1189 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1190} 1191 1192/// EmitInt16 - Emit a short directive and value. 1193/// 1194void AsmPrinter::EmitInt16(int Value) const { 1195 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1196} 1197 1198/// EmitInt32 - Emit a long directive and value. 1199/// 1200void AsmPrinter::EmitInt32(int Value) const { 1201 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1202} 1203 1204/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1205/// in bytes of the directive is specified by Size and Hi/Lo specify the 1206/// labels. This implicitly uses .set if it is available. 1207void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1208 unsigned Size) const { 1209 // Get the Hi-Lo expression. 1210 const MCExpr *Diff = 1211 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1212 MCSymbolRefExpr::Create(Lo, OutContext), 1213 OutContext); 1214 1215 if (!MAI->hasSetDirective()) { 1216 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1217 return; 1218 } 1219 1220 // Otherwise, emit with .set (aka assignment). 1221 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1222 OutStreamer.EmitAssignment(SetLabel, Diff); 1223 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1224} 1225 1226/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1227/// where the size in bytes of the directive is specified by Size and Hi/Lo 1228/// specify the labels. This implicitly uses .set if it is available. 1229void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1230 const MCSymbol *Lo, unsigned Size) 1231 const { 1232 1233 // Emit Hi+Offset - Lo 1234 // Get the Hi+Offset expression. 1235 const MCExpr *Plus = 1236 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1237 MCConstantExpr::Create(Offset, OutContext), 1238 OutContext); 1239 1240 // Get the Hi+Offset-Lo expression. 1241 const MCExpr *Diff = 1242 MCBinaryExpr::CreateSub(Plus, 1243 MCSymbolRefExpr::Create(Lo, OutContext), 1244 OutContext); 1245 1246 if (!MAI->hasSetDirective()) 1247 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1248 else { 1249 // Otherwise, emit with .set (aka assignment). 1250 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1251 OutStreamer.EmitAssignment(SetLabel, Diff); 1252 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1253 } 1254} 1255 1256/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1257/// where the size in bytes of the directive is specified by Size and Label 1258/// specifies the label. This implicitly uses .set if it is available. 1259void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1260 unsigned Size) 1261 const { 1262 1263 // Emit Label+Offset 1264 const MCExpr *Plus = 1265 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1266 MCConstantExpr::Create(Offset, OutContext), 1267 OutContext); 1268 1269 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1270} 1271 1272 1273//===----------------------------------------------------------------------===// 1274 1275// EmitAlignment - Emit an alignment directive to the specified power of 1276// two boundary. For example, if you pass in 3 here, you will get an 8 1277// byte alignment. If a global value is specified, and if that global has 1278// an explicit alignment requested, it will override the alignment request 1279// if required for correctness. 1280// 1281void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1282 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1283 1284 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1285 1286 if (getCurrentSection()->getKind().isText()) 1287 OutStreamer.EmitCodeAlignment(1 << NumBits); 1288 else 1289 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1290} 1291 1292//===----------------------------------------------------------------------===// 1293// Constant emission. 1294//===----------------------------------------------------------------------===// 1295 1296/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1297/// 1298static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1299 MCContext &Ctx = AP.OutContext; 1300 1301 if (CV->isNullValue() || isa<UndefValue>(CV)) 1302 return MCConstantExpr::Create(0, Ctx); 1303 1304 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1305 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1306 1307 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1308 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1309 1310 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1311 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1312 1313 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1314 if (CE == 0) { 1315 llvm_unreachable("Unknown constant value to lower!"); 1316 return MCConstantExpr::Create(0, Ctx); 1317 } 1318 1319 switch (CE->getOpcode()) { 1320 default: 1321 // If the code isn't optimized, there may be outstanding folding 1322 // opportunities. Attempt to fold the expression using TargetData as a 1323 // last resort before giving up. 1324 if (Constant *C = 1325 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1326 if (C != CE) 1327 return LowerConstant(C, AP); 1328 1329 // Otherwise report the problem to the user. 1330 { 1331 std::string S; 1332 raw_string_ostream OS(S); 1333 OS << "Unsupported expression in static initializer: "; 1334 WriteAsOperand(OS, CE, /*PrintType=*/false, 1335 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1336 report_fatal_error(OS.str()); 1337 } 1338 return MCConstantExpr::Create(0, Ctx); 1339 case Instruction::GetElementPtr: { 1340 const TargetData &TD = *AP.TM.getTargetData(); 1341 // Generate a symbolic expression for the byte address 1342 const Constant *PtrVal = CE->getOperand(0); 1343 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1344 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1345 IdxVec.size()); 1346 1347 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1348 if (Offset == 0) 1349 return Base; 1350 1351 // Truncate/sext the offset to the pointer size. 1352 if (TD.getPointerSizeInBits() != 64) { 1353 int SExtAmount = 64-TD.getPointerSizeInBits(); 1354 Offset = (Offset << SExtAmount) >> SExtAmount; 1355 } 1356 1357 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1358 Ctx); 1359 } 1360 1361 case Instruction::Trunc: 1362 // We emit the value and depend on the assembler to truncate the generated 1363 // expression properly. This is important for differences between 1364 // blockaddress labels. Since the two labels are in the same function, it 1365 // is reasonable to treat their delta as a 32-bit value. 1366 // FALL THROUGH. 1367 case Instruction::BitCast: 1368 return LowerConstant(CE->getOperand(0), AP); 1369 1370 case Instruction::IntToPtr: { 1371 const TargetData &TD = *AP.TM.getTargetData(); 1372 // Handle casts to pointers by changing them into casts to the appropriate 1373 // integer type. This promotes constant folding and simplifies this code. 1374 Constant *Op = CE->getOperand(0); 1375 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1376 false/*ZExt*/); 1377 return LowerConstant(Op, AP); 1378 } 1379 1380 case Instruction::PtrToInt: { 1381 const TargetData &TD = *AP.TM.getTargetData(); 1382 // Support only foldable casts to/from pointers that can be eliminated by 1383 // changing the pointer to the appropriately sized integer type. 1384 Constant *Op = CE->getOperand(0); 1385 const Type *Ty = CE->getType(); 1386 1387 const MCExpr *OpExpr = LowerConstant(Op, AP); 1388 1389 // We can emit the pointer value into this slot if the slot is an 1390 // integer slot equal to the size of the pointer. 1391 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1392 return OpExpr; 1393 1394 // Otherwise the pointer is smaller than the resultant integer, mask off 1395 // the high bits so we are sure to get a proper truncation if the input is 1396 // a constant expr. 1397 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1398 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1399 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1400 } 1401 1402 // The MC library also has a right-shift operator, but it isn't consistently 1403 // signed or unsigned between different targets. 1404 case Instruction::Add: 1405 case Instruction::Sub: 1406 case Instruction::Mul: 1407 case Instruction::SDiv: 1408 case Instruction::SRem: 1409 case Instruction::Shl: 1410 case Instruction::And: 1411 case Instruction::Or: 1412 case Instruction::Xor: { 1413 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1414 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1415 switch (CE->getOpcode()) { 1416 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1417 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1418 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1419 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1420 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1421 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1422 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1423 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1424 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1425 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1426 } 1427 } 1428 } 1429} 1430 1431static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1432 AsmPrinter &AP); 1433 1434static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1435 AsmPrinter &AP) { 1436 if (AddrSpace != 0 || !CA->isString()) { 1437 // Not a string. Print the values in successive locations 1438 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1439 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1440 return; 1441 } 1442 1443 // Otherwise, it can be emitted as .ascii. 1444 SmallVector<char, 128> TmpVec; 1445 TmpVec.reserve(CA->getNumOperands()); 1446 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1447 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1448 1449 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1450} 1451 1452static void EmitGlobalConstantVector(const ConstantVector *CV, 1453 unsigned AddrSpace, AsmPrinter &AP) { 1454 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1455 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1456} 1457 1458static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1459 unsigned AddrSpace, AsmPrinter &AP) { 1460 // Print the fields in successive locations. Pad to align if needed! 1461 const TargetData *TD = AP.TM.getTargetData(); 1462 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1463 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1464 uint64_t SizeSoFar = 0; 1465 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1466 const Constant *Field = CS->getOperand(i); 1467 1468 // Check if padding is needed and insert one or more 0s. 1469 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1470 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1471 - Layout->getElementOffset(i)) - FieldSize; 1472 SizeSoFar += FieldSize + PadSize; 1473 1474 // Now print the actual field value. 1475 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1476 1477 // Insert padding - this may include padding to increase the size of the 1478 // current field up to the ABI size (if the struct is not packed) as well 1479 // as padding to ensure that the next field starts at the right offset. 1480 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1481 } 1482 assert(SizeSoFar == Layout->getSizeInBytes() && 1483 "Layout of constant struct may be incorrect!"); 1484} 1485 1486static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1487 AsmPrinter &AP) { 1488 // FP Constants are printed as integer constants to avoid losing 1489 // precision. 1490 if (CFP->getType()->isDoubleTy()) { 1491 if (AP.isVerbose()) { 1492 double Val = CFP->getValueAPF().convertToDouble(); 1493 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1494 } 1495 1496 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1497 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1498 return; 1499 } 1500 1501 if (CFP->getType()->isFloatTy()) { 1502 if (AP.isVerbose()) { 1503 float Val = CFP->getValueAPF().convertToFloat(); 1504 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1505 } 1506 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1507 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1508 return; 1509 } 1510 1511 if (CFP->getType()->isX86_FP80Ty()) { 1512 // all long double variants are printed as hex 1513 // API needed to prevent premature destruction 1514 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1515 const uint64_t *p = API.getRawData(); 1516 if (AP.isVerbose()) { 1517 // Convert to double so we can print the approximate val as a comment. 1518 APFloat DoubleVal = CFP->getValueAPF(); 1519 bool ignored; 1520 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1521 &ignored); 1522 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1523 << DoubleVal.convertToDouble() << '\n'; 1524 } 1525 1526 if (AP.TM.getTargetData()->isBigEndian()) { 1527 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1528 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1529 } else { 1530 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1531 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1532 } 1533 1534 // Emit the tail padding for the long double. 1535 const TargetData &TD = *AP.TM.getTargetData(); 1536 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1537 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1538 return; 1539 } 1540 1541 assert(CFP->getType()->isPPC_FP128Ty() && 1542 "Floating point constant type not handled"); 1543 // All long double variants are printed as hex 1544 // API needed to prevent premature destruction. 1545 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1546 const uint64_t *p = API.getRawData(); 1547 if (AP.TM.getTargetData()->isBigEndian()) { 1548 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1549 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1550 } else { 1551 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1552 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1553 } 1554} 1555 1556static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1557 unsigned AddrSpace, AsmPrinter &AP) { 1558 const TargetData *TD = AP.TM.getTargetData(); 1559 unsigned BitWidth = CI->getBitWidth(); 1560 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1561 1562 // We don't expect assemblers to support integer data directives 1563 // for more than 64 bits, so we emit the data in at most 64-bit 1564 // quantities at a time. 1565 const uint64_t *RawData = CI->getValue().getRawData(); 1566 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1567 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1568 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1569 } 1570} 1571 1572static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1573 AsmPrinter &AP) { 1574 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1575 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1576 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1577 } 1578 1579 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1580 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1581 switch (Size) { 1582 case 1: 1583 case 2: 1584 case 4: 1585 case 8: 1586 if (AP.isVerbose()) 1587 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1588 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1589 return; 1590 default: 1591 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1592 return; 1593 } 1594 } 1595 1596 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1597 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1598 1599 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1600 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1601 1602 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1603 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1604 1605 if (isa<ConstantPointerNull>(CV)) { 1606 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1607 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1608 return; 1609 } 1610 1611 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1612 return EmitGlobalConstantVector(V, AddrSpace, AP); 1613 1614 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1615 // thread the streamer with EmitValue. 1616 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1617 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1618 AddrSpace); 1619} 1620 1621/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1622void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1623 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1624 if (Size) 1625 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1626 else if (MAI->hasSubsectionsViaSymbols()) { 1627 // If the global has zero size, emit a single byte so that two labels don't 1628 // look like they are at the same location. 1629 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1630 } 1631} 1632 1633void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1634 // Target doesn't support this yet! 1635 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1636} 1637 1638void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1639 if (Offset > 0) 1640 OS << '+' << Offset; 1641 else if (Offset < 0) 1642 OS << Offset; 1643} 1644 1645//===----------------------------------------------------------------------===// 1646// Symbol Lowering Routines. 1647//===----------------------------------------------------------------------===// 1648 1649/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1650/// temporary label with the specified stem and unique ID. 1651MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1652 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1653 Name + Twine(ID)); 1654} 1655 1656/// GetTempSymbol - Return an assembler temporary label with the specified 1657/// stem. 1658MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1659 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1660 Name); 1661} 1662 1663 1664MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1665 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1666} 1667 1668MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1669 return MMI->getAddrLabelSymbol(BB); 1670} 1671 1672/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1673MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1674 return OutContext.GetOrCreateSymbol 1675 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1676 + "_" + Twine(CPID)); 1677} 1678 1679/// GetJTISymbol - Return the symbol for the specified jump table entry. 1680MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1681 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1682} 1683 1684/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1685/// FIXME: privatize to AsmPrinter. 1686MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1687 return OutContext.GetOrCreateSymbol 1688 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1689 Twine(UID) + "_set_" + Twine(MBBID)); 1690} 1691 1692/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1693/// global value name as its base, with the specified suffix, and where the 1694/// symbol is forced to have private linkage if ForcePrivate is true. 1695MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1696 StringRef Suffix, 1697 bool ForcePrivate) const { 1698 SmallString<60> NameStr; 1699 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1700 NameStr.append(Suffix.begin(), Suffix.end()); 1701 return OutContext.GetOrCreateSymbol(NameStr.str()); 1702} 1703 1704/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1705/// ExternalSymbol. 1706MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1707 SmallString<60> NameStr; 1708 Mang->getNameWithPrefix(NameStr, Sym); 1709 return OutContext.GetOrCreateSymbol(NameStr.str()); 1710} 1711 1712 1713 1714/// PrintParentLoopComment - Print comments about parent loops of this one. 1715static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1716 unsigned FunctionNumber) { 1717 if (Loop == 0) return; 1718 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1719 OS.indent(Loop->getLoopDepth()*2) 1720 << "Parent Loop BB" << FunctionNumber << "_" 1721 << Loop->getHeader()->getNumber() 1722 << " Depth=" << Loop->getLoopDepth() << '\n'; 1723} 1724 1725 1726/// PrintChildLoopComment - Print comments about child loops within 1727/// the loop for this basic block, with nesting. 1728static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1729 unsigned FunctionNumber) { 1730 // Add child loop information 1731 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1732 OS.indent((*CL)->getLoopDepth()*2) 1733 << "Child Loop BB" << FunctionNumber << "_" 1734 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1735 << '\n'; 1736 PrintChildLoopComment(OS, *CL, FunctionNumber); 1737 } 1738} 1739 1740/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1741static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1742 const MachineLoopInfo *LI, 1743 const AsmPrinter &AP) { 1744 // Add loop depth information 1745 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1746 if (Loop == 0) return; 1747 1748 MachineBasicBlock *Header = Loop->getHeader(); 1749 assert(Header && "No header for loop"); 1750 1751 // If this block is not a loop header, just print out what is the loop header 1752 // and return. 1753 if (Header != &MBB) { 1754 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1755 Twine(AP.getFunctionNumber())+"_" + 1756 Twine(Loop->getHeader()->getNumber())+ 1757 " Depth="+Twine(Loop->getLoopDepth())); 1758 return; 1759 } 1760 1761 // Otherwise, it is a loop header. Print out information about child and 1762 // parent loops. 1763 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1764 1765 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1766 1767 OS << "=>"; 1768 OS.indent(Loop->getLoopDepth()*2-2); 1769 1770 OS << "This "; 1771 if (Loop->empty()) 1772 OS << "Inner "; 1773 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1774 1775 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1776} 1777 1778 1779/// EmitBasicBlockStart - This method prints the label for the specified 1780/// MachineBasicBlock, an alignment (if present) and a comment describing 1781/// it if appropriate. 1782void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1783 // Emit an alignment directive for this block, if needed. 1784 if (unsigned Align = MBB->getAlignment()) 1785 EmitAlignment(Log2_32(Align)); 1786 1787 // If the block has its address taken, emit any labels that were used to 1788 // reference the block. It is possible that there is more than one label 1789 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1790 // the references were generated. 1791 if (MBB->hasAddressTaken()) { 1792 const BasicBlock *BB = MBB->getBasicBlock(); 1793 if (isVerbose()) 1794 OutStreamer.AddComment("Block address taken"); 1795 1796 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1797 1798 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1799 OutStreamer.EmitLabel(Syms[i]); 1800 } 1801 1802 // Print the main label for the block. 1803 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1804 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1805 if (const BasicBlock *BB = MBB->getBasicBlock()) 1806 if (BB->hasName()) 1807 OutStreamer.AddComment("%" + BB->getName()); 1808 1809 EmitBasicBlockLoopComments(*MBB, LI, *this); 1810 1811 // NOTE: Want this comment at start of line, don't emit with AddComment. 1812 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1813 Twine(MBB->getNumber()) + ":"); 1814 } 1815 } else { 1816 if (isVerbose()) { 1817 if (const BasicBlock *BB = MBB->getBasicBlock()) 1818 if (BB->hasName()) 1819 OutStreamer.AddComment("%" + BB->getName()); 1820 EmitBasicBlockLoopComments(*MBB, LI, *this); 1821 } 1822 1823 OutStreamer.EmitLabel(MBB->getSymbol()); 1824 } 1825} 1826 1827void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 1828 bool IsDefinition) const { 1829 MCSymbolAttr Attr = MCSA_Invalid; 1830 1831 switch (Visibility) { 1832 default: break; 1833 case GlobalValue::HiddenVisibility: 1834 if (IsDefinition) 1835 Attr = MAI->getHiddenVisibilityAttr(); 1836 else 1837 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 1838 break; 1839 case GlobalValue::ProtectedVisibility: 1840 Attr = MAI->getProtectedVisibilityAttr(); 1841 break; 1842 } 1843 1844 if (Attr != MCSA_Invalid) 1845 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1846} 1847 1848/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1849/// exactly one predecessor and the control transfer mechanism between 1850/// the predecessor and this block is a fall-through. 1851bool AsmPrinter:: 1852isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1853 // If this is a landing pad, it isn't a fall through. If it has no preds, 1854 // then nothing falls through to it. 1855 if (MBB->isLandingPad() || MBB->pred_empty()) 1856 return false; 1857 1858 // If there isn't exactly one predecessor, it can't be a fall through. 1859 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1860 ++PI2; 1861 if (PI2 != MBB->pred_end()) 1862 return false; 1863 1864 // The predecessor has to be immediately before this block. 1865 const MachineBasicBlock *Pred = *PI; 1866 1867 if (!Pred->isLayoutSuccessor(MBB)) 1868 return false; 1869 1870 // If the block is completely empty, then it definitely does fall through. 1871 if (Pred->empty()) 1872 return true; 1873 1874 // Otherwise, check the last instruction. 1875 const MachineInstr &LastInst = Pred->back(); 1876 return !LastInst.getDesc().isBarrier(); 1877} 1878 1879 1880 1881GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1882 if (!S->usesMetadata()) 1883 return 0; 1884 1885 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1886 gcp_map_type::iterator GCPI = GCMap.find(S); 1887 if (GCPI != GCMap.end()) 1888 return GCPI->second; 1889 1890 const char *Name = S->getName().c_str(); 1891 1892 for (GCMetadataPrinterRegistry::iterator 1893 I = GCMetadataPrinterRegistry::begin(), 1894 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1895 if (strcmp(Name, I->getName()) == 0) { 1896 GCMetadataPrinter *GMP = I->instantiate(); 1897 GMP->S = S; 1898 GCMap.insert(std::make_pair(S, GMP)); 1899 return GMP; 1900 } 1901 1902 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1903 return 0; 1904} 1905 1906