AsmPrinter.cpp revision fdc794a7f748a2b83c8a2e32378111785ad53146
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/TargetRegisterInfo.h" 41#include "llvm/ADT/SmallString.h" 42#include "llvm/ADT/Statistic.h" 43#include "llvm/Support/ErrorHandling.h" 44#include "llvm/Support/Format.h" 45#include "llvm/Support/Timer.h" 46using namespace llvm; 47 48static const char *DWARFGroupName = "DWARF Emission"; 49static const char *DbgTimerName = "DWARF Debug Writer"; 50static const char *EHTimerName = "DWARF Exception Writer"; 51 52STATISTIC(EmittedInsts, "Number of machine instrs printed"); 53 54char AsmPrinter::ID = 0; 55 56typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 57static gcp_map_type &getGCMap(void *&P) { 58 if (P == 0) 59 P = new gcp_map_type(); 60 return *(gcp_map_type*)P; 61} 62 63 64/// getGVAlignmentLog2 - Return the alignment to use for the specified global 65/// value in log2 form. This rounds up to the preferred alignment if possible 66/// and legal. 67static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 68 unsigned InBits = 0) { 69 unsigned NumBits = 0; 70 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 71 NumBits = TD.getPreferredAlignmentLog(GVar); 72 73 // If InBits is specified, round it to it. 74 if (InBits > NumBits) 75 NumBits = InBits; 76 77 // If the GV has a specified alignment, take it into account. 78 if (GV->getAlignment() == 0) 79 return NumBits; 80 81 unsigned GVAlign = Log2_32(GV->getAlignment()); 82 83 // If the GVAlign is larger than NumBits, or if we are required to obey 84 // NumBits because the GV has an assigned section, obey it. 85 if (GVAlign > NumBits || GV->hasSection()) 86 NumBits = GVAlign; 87 return NumBits; 88} 89 90 91 92 93AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 94 : MachineFunctionPass(&ID), 95 TM(tm), MAI(tm.getMCAsmInfo()), 96 OutContext(Streamer.getContext()), 97 OutStreamer(Streamer), 98 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 99 DD = 0; DE = 0; MMI = 0; LI = 0; 100 GCMetadataPrinters = 0; 101 VerboseAsm = Streamer.isVerboseAsm(); 102} 103 104AsmPrinter::~AsmPrinter() { 105 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 106 107 if (GCMetadataPrinters != 0) { 108 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 109 110 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 111 delete I->second; 112 delete &GCMap; 113 GCMetadataPrinters = 0; 114 } 115 116 delete &OutStreamer; 117} 118 119/// getFunctionNumber - Return a unique ID for the current function. 120/// 121unsigned AsmPrinter::getFunctionNumber() const { 122 return MF->getFunctionNumber(); 123} 124 125const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 126 return TM.getTargetLowering()->getObjFileLowering(); 127} 128 129 130/// getTargetData - Return information about data layout. 131const TargetData &AsmPrinter::getTargetData() const { 132 return *TM.getTargetData(); 133} 134 135/// getCurrentSection() - Return the current section we are emitting to. 136const MCSection *AsmPrinter::getCurrentSection() const { 137 return OutStreamer.getCurrentSection(); 138} 139 140 141 142void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 143 AU.setPreservesAll(); 144 MachineFunctionPass::getAnalysisUsage(AU); 145 AU.addRequired<MachineModuleInfo>(); 146 AU.addRequired<GCModuleInfo>(); 147 if (isVerbose()) 148 AU.addRequired<MachineLoopInfo>(); 149} 150 151bool AsmPrinter::doInitialization(Module &M) { 152 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 153 MMI->AnalyzeModule(M); 154 155 // Initialize TargetLoweringObjectFile. 156 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 157 .Initialize(OutContext, TM); 158 159 Mang = new Mangler(OutContext, *TM.getTargetData()); 160 161 // Allow the target to emit any magic that it wants at the start of the file. 162 EmitStartOfAsmFile(M); 163 164 // Very minimal debug info. It is ignored if we emit actual debug info. If we 165 // don't, this at least helps the user find where a global came from. 166 if (MAI->hasSingleParameterDotFile()) { 167 // .file "foo.c" 168 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 169 } 170 171 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 172 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 173 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 174 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 175 MP->beginAssembly(*this); 176 177 // Emit module-level inline asm if it exists. 178 if (!M.getModuleInlineAsm().empty()) { 179 OutStreamer.AddComment("Start of file scope inline assembly"); 180 OutStreamer.AddBlankLine(); 181 EmitInlineAsm(M.getModuleInlineAsm(), 0/*no loc cookie*/); 182 OutStreamer.AddComment("End of file scope inline assembly"); 183 OutStreamer.AddBlankLine(); 184 } 185 186 if (MAI->doesSupportDebugInformation()) 187 DD = new DwarfDebug(this, &M); 188 189 if (MAI->doesSupportExceptionHandling()) 190 DE = new DwarfException(this); 191 192 return false; 193} 194 195void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 196 switch ((GlobalValue::LinkageTypes)Linkage) { 197 case GlobalValue::CommonLinkage: 198 case GlobalValue::LinkOnceAnyLinkage: 199 case GlobalValue::LinkOnceODRLinkage: 200 case GlobalValue::WeakAnyLinkage: 201 case GlobalValue::WeakODRLinkage: 202 case GlobalValue::LinkerPrivateLinkage: 203 if (MAI->getWeakDefDirective() != 0) { 204 // .globl _foo 205 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 206 // .weak_definition _foo 207 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 208 } else if (MAI->getLinkOnceDirective() != 0) { 209 // .globl _foo 210 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 211 //NOTE: linkonce is handled by the section the symbol was assigned to. 212 } else { 213 // .weak _foo 214 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 215 } 216 break; 217 case GlobalValue::DLLExportLinkage: 218 case GlobalValue::AppendingLinkage: 219 // FIXME: appending linkage variables should go into a section of 220 // their name or something. For now, just emit them as external. 221 case GlobalValue::ExternalLinkage: 222 // If external or appending, declare as a global symbol. 223 // .globl _foo 224 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 225 break; 226 case GlobalValue::PrivateLinkage: 227 case GlobalValue::InternalLinkage: 228 break; 229 default: 230 llvm_unreachable("Unknown linkage type!"); 231 } 232} 233 234 235/// EmitGlobalVariable - Emit the specified global variable to the .s file. 236void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 237 if (!GV->hasInitializer()) // External globals require no code. 238 return; 239 240 // Check to see if this is a special global used by LLVM, if so, emit it. 241 if (EmitSpecialLLVMGlobal(GV)) 242 return; 243 244 MCSymbol *GVSym = Mang->getSymbol(GV); 245 EmitVisibility(GVSym, GV->getVisibility()); 246 247 if (MAI->hasDotTypeDotSizeDirective()) 248 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 249 250 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 251 252 const TargetData *TD = TM.getTargetData(); 253 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 254 255 // If the alignment is specified, we *must* obey it. Overaligning a global 256 // with a specified alignment is a prompt way to break globals emitted to 257 // sections and expected to be contiguous (e.g. ObjC metadata). 258 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 259 260 // Handle common and BSS local symbols (.lcomm). 261 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 262 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 263 264 if (isVerbose()) { 265 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 266 /*PrintType=*/false, GV->getParent()); 267 OutStreamer.GetCommentOS() << '\n'; 268 } 269 270 // Handle common symbols. 271 if (GVKind.isCommon()) { 272 // .comm _foo, 42, 4 273 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 274 return; 275 } 276 277 // Handle local BSS symbols. 278 if (MAI->hasMachoZeroFillDirective()) { 279 const MCSection *TheSection = 280 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 281 // .zerofill __DATA, __bss, _foo, 400, 5 282 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 283 return; 284 } 285 286 if (MAI->hasLCOMMDirective()) { 287 // .lcomm _foo, 42 288 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 289 return; 290 } 291 292 // .local _foo 293 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 294 // .comm _foo, 42, 4 295 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 296 return; 297 } 298 299 const MCSection *TheSection = 300 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 301 302 // Handle the zerofill directive on darwin, which is a special form of BSS 303 // emission. 304 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 305 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 306 307 // .globl _foo 308 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 309 // .zerofill __DATA, __common, _foo, 400, 5 310 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 311 return; 312 } 313 314 // Handle thread local data for mach-o which requires us to output an 315 // additional structure of data and mangle the original symbol so that we 316 // can reference it later. 317 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 318 // Emit the .tbss symbol 319 MCSymbol *MangSym = 320 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 321 322 if (GVKind.isThreadBSS()) 323 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 324 else if (GVKind.isThreadData()) { 325 OutStreamer.SwitchSection(TheSection); 326 327 EmitLinkage(GV->getLinkage(), MangSym); 328 EmitAlignment(AlignLog, GV); 329 OutStreamer.EmitLabel(MangSym); 330 331 EmitGlobalConstant(GV->getInitializer()); 332 } 333 334 OutStreamer.AddBlankLine(); 335 336 // Emit the variable struct for the runtime. 337 const MCSection *TLVSect 338 = getObjFileLowering().getTLSExtraDataSection(); 339 340 OutStreamer.SwitchSection(TLVSect); 341 // Emit the linkage here. 342 EmitLinkage(GV->getLinkage(), GVSym); 343 OutStreamer.EmitLabel(GVSym); 344 345 // Three pointers in size: 346 // - __tlv_bootstrap - used to make sure support exists 347 // - spare pointer, used when mapped by the runtime 348 // - pointer to mangled symbol above with initializer 349 unsigned PtrSize = TD->getPointerSizeInBits()/8; 350 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__tlv_bootstrap"), 351 PtrSize, 0); 352 OutStreamer.EmitIntValue(0, PtrSize, 0); 353 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 354 355 OutStreamer.AddBlankLine(); 356 return; 357 } 358 359 OutStreamer.SwitchSection(TheSection); 360 361 EmitLinkage(GV->getLinkage(), GVSym); 362 EmitAlignment(AlignLog, GV); 363 364 if (isVerbose()) { 365 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 366 /*PrintType=*/false, GV->getParent()); 367 OutStreamer.GetCommentOS() << '\n'; 368 } 369 OutStreamer.EmitLabel(GVSym); 370 371 EmitGlobalConstant(GV->getInitializer()); 372 373 if (MAI->hasDotTypeDotSizeDirective()) 374 // .size foo, 42 375 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 376 377 OutStreamer.AddBlankLine(); 378} 379 380/// EmitFunctionHeader - This method emits the header for the current 381/// function. 382void AsmPrinter::EmitFunctionHeader() { 383 // Print out constants referenced by the function 384 EmitConstantPool(); 385 386 // Print the 'header' of function. 387 const Function *F = MF->getFunction(); 388 389 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 390 EmitVisibility(CurrentFnSym, F->getVisibility()); 391 392 EmitLinkage(F->getLinkage(), CurrentFnSym); 393 EmitAlignment(MF->getAlignment(), F); 394 395 if (MAI->hasDotTypeDotSizeDirective()) 396 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 397 398 if (isVerbose()) { 399 WriteAsOperand(OutStreamer.GetCommentOS(), F, 400 /*PrintType=*/false, F->getParent()); 401 OutStreamer.GetCommentOS() << '\n'; 402 } 403 404 // Emit the CurrentFnSym. This is a virtual function to allow targets to 405 // do their wild and crazy things as required. 406 EmitFunctionEntryLabel(); 407 408 // If the function had address-taken blocks that got deleted, then we have 409 // references to the dangling symbols. Emit them at the start of the function 410 // so that we don't get references to undefined symbols. 411 std::vector<MCSymbol*> DeadBlockSyms; 412 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 413 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 414 OutStreamer.AddComment("Address taken block that was later removed"); 415 OutStreamer.EmitLabel(DeadBlockSyms[i]); 416 } 417 418 // Add some workaround for linkonce linkage on Cygwin\MinGW. 419 if (MAI->getLinkOnceDirective() != 0 && 420 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 421 // FIXME: What is this? 422 MCSymbol *FakeStub = 423 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 424 CurrentFnSym->getName()); 425 OutStreamer.EmitLabel(FakeStub); 426 } 427 428 // Emit pre-function debug and/or EH information. 429 if (DE) { 430 if (TimePassesIsEnabled) { 431 NamedRegionTimer T(EHTimerName, DWARFGroupName); 432 DE->BeginFunction(MF); 433 } else { 434 DE->BeginFunction(MF); 435 } 436 } 437 if (DD) { 438 if (TimePassesIsEnabled) { 439 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 440 DD->beginFunction(MF); 441 } else { 442 DD->beginFunction(MF); 443 } 444 } 445} 446 447/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 448/// function. This can be overridden by targets as required to do custom stuff. 449void AsmPrinter::EmitFunctionEntryLabel() { 450 // The function label could have already been emitted if two symbols end up 451 // conflicting due to asm renaming. Detect this and emit an error. 452 if (CurrentFnSym->isUndefined()) 453 return OutStreamer.EmitLabel(CurrentFnSym); 454 455 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 456 "' label emitted multiple times to assembly file"); 457} 458 459 460/// EmitComments - Pretty-print comments for instructions. 461static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 462 const MachineFunction *MF = MI.getParent()->getParent(); 463 const TargetMachine &TM = MF->getTarget(); 464 465 DebugLoc DL = MI.getDebugLoc(); 466 if (!DL.isUnknown()) { // Print source line info. 467 DIScope Scope(DL.getScope(MF->getFunction()->getContext())); 468 // Omit the directory, because it's likely to be long and uninteresting. 469 if (Scope.Verify()) 470 CommentOS << Scope.getFilename(); 471 else 472 CommentOS << "<unknown>"; 473 CommentOS << ':' << DL.getLine(); 474 if (DL.getCol() != 0) 475 CommentOS << ':' << DL.getCol(); 476 CommentOS << '\n'; 477 } 478 479 // Check for spills and reloads 480 int FI; 481 482 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 483 484 // We assume a single instruction only has a spill or reload, not 485 // both. 486 const MachineMemOperand *MMO; 487 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 488 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 489 MMO = *MI.memoperands_begin(); 490 CommentOS << MMO->getSize() << "-byte Reload\n"; 491 } 492 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 493 if (FrameInfo->isSpillSlotObjectIndex(FI)) 494 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 495 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 496 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 497 MMO = *MI.memoperands_begin(); 498 CommentOS << MMO->getSize() << "-byte Spill\n"; 499 } 500 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 501 if (FrameInfo->isSpillSlotObjectIndex(FI)) 502 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 503 } 504 505 // Check for spill-induced copies 506 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; 507 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg, 508 SrcSubIdx, DstSubIdx)) { 509 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 510 CommentOS << " Reload Reuse\n"; 511 } 512} 513 514/// EmitImplicitDef - This method emits the specified machine instruction 515/// that is an implicit def. 516static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 517 unsigned RegNo = MI->getOperand(0).getReg(); 518 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 519 AP.TM.getRegisterInfo()->getName(RegNo)); 520 AP.OutStreamer.AddBlankLine(); 521} 522 523static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 524 std::string Str = "kill:"; 525 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 526 const MachineOperand &Op = MI->getOperand(i); 527 assert(Op.isReg() && "KILL instruction must have only register operands"); 528 Str += ' '; 529 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 530 Str += (Op.isDef() ? "<def>" : "<kill>"); 531 } 532 AP.OutStreamer.AddComment(Str); 533 AP.OutStreamer.AddBlankLine(); 534} 535 536/// EmitDebugValueComment - This method handles the target-independent form 537/// of DBG_VALUE, returning true if it was able to do so. A false return 538/// means the target will need to handle MI in EmitInstruction. 539static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 540 // This code handles only the 3-operand target-independent form. 541 if (MI->getNumOperands() != 3) 542 return false; 543 544 SmallString<128> Str; 545 raw_svector_ostream OS(Str); 546 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 547 548 // cast away const; DIetc do not take const operands for some reason. 549 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 550 if (V.getContext().isSubprogram()) 551 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 552 OS << V.getName() << " <- "; 553 554 // Register or immediate value. Register 0 means undef. 555 if (MI->getOperand(0).isFPImm()) { 556 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 557 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 558 OS << (double)APF.convertToFloat(); 559 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 560 OS << APF.convertToDouble(); 561 } else { 562 // There is no good way to print long double. Convert a copy to 563 // double. Ah well, it's only a comment. 564 bool ignored; 565 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 566 &ignored); 567 OS << "(long double) " << APF.convertToDouble(); 568 } 569 } else if (MI->getOperand(0).isImm()) { 570 OS << MI->getOperand(0).getImm(); 571 } else { 572 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 573 if (MI->getOperand(0).getReg() == 0) { 574 // Suppress offset, it is not meaningful here. 575 OS << "undef"; 576 // NOTE: Want this comment at start of line, don't emit with AddComment. 577 AP.OutStreamer.EmitRawText(OS.str()); 578 return true; 579 } 580 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 581 } 582 583 OS << '+' << MI->getOperand(1).getImm(); 584 // NOTE: Want this comment at start of line, don't emit with AddComment. 585 AP.OutStreamer.EmitRawText(OS.str()); 586 return true; 587} 588 589/// EmitFunctionBody - This method emits the body and trailer for a 590/// function. 591void AsmPrinter::EmitFunctionBody() { 592 // Emit target-specific gunk before the function body. 593 EmitFunctionBodyStart(); 594 595 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 596 597 // Print out code for the function. 598 bool HasAnyRealCode = false; 599 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 600 I != E; ++I) { 601 // Print a label for the basic block. 602 EmitBasicBlockStart(I); 603 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 604 II != IE; ++II) { 605 // Print the assembly for the instruction. 606 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 607 !II->isDebugValue()) { 608 HasAnyRealCode = true; 609 ++EmittedInsts; 610 } 611 612 if (ShouldPrintDebugScopes) { 613 if (TimePassesIsEnabled) { 614 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 615 DD->beginScope(II); 616 } else { 617 DD->beginScope(II); 618 } 619 } 620 621 if (isVerbose()) 622 EmitComments(*II, OutStreamer.GetCommentOS()); 623 624 switch (II->getOpcode()) { 625 case TargetOpcode::DBG_LABEL: 626 case TargetOpcode::EH_LABEL: 627 case TargetOpcode::GC_LABEL: 628 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 629 break; 630 case TargetOpcode::INLINEASM: 631 EmitInlineAsm(II); 632 break; 633 case TargetOpcode::DBG_VALUE: 634 if (isVerbose()) { 635 if (!EmitDebugValueComment(II, *this)) 636 EmitInstruction(II); 637 } 638 break; 639 case TargetOpcode::IMPLICIT_DEF: 640 if (isVerbose()) EmitImplicitDef(II, *this); 641 break; 642 case TargetOpcode::KILL: 643 if (isVerbose()) EmitKill(II, *this); 644 break; 645 default: 646 EmitInstruction(II); 647 break; 648 } 649 650 if (ShouldPrintDebugScopes) { 651 if (TimePassesIsEnabled) { 652 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 653 DD->endScope(II); 654 } else { 655 DD->endScope(II); 656 } 657 } 658 } 659 } 660 661 // If the function is empty and the object file uses .subsections_via_symbols, 662 // then we need to emit *something* to the function body to prevent the 663 // labels from collapsing together. Just emit a noop. 664 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) { 665 MCInst Noop; 666 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 667 if (Noop.getOpcode()) { 668 OutStreamer.AddComment("avoids zero-length function"); 669 OutStreamer.EmitInstruction(Noop); 670 } else // Target not mc-ized yet. 671 OutStreamer.EmitRawText(StringRef("\tnop\n")); 672 } 673 674 // Emit target-specific gunk after the function body. 675 EmitFunctionBodyEnd(); 676 677 // If the target wants a .size directive for the size of the function, emit 678 // it. 679 if (MAI->hasDotTypeDotSizeDirective()) { 680 // Create a symbol for the end of function, so we can get the size as 681 // difference between the function label and the temp label. 682 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 683 OutStreamer.EmitLabel(FnEndLabel); 684 685 const MCExpr *SizeExp = 686 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 687 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 688 OutContext); 689 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 690 } 691 692 // Emit post-function debug information. 693 if (DD) { 694 if (TimePassesIsEnabled) { 695 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 696 DD->endFunction(MF); 697 } else { 698 DD->endFunction(MF); 699 } 700 } 701 if (DE) { 702 if (TimePassesIsEnabled) { 703 NamedRegionTimer T(EHTimerName, DWARFGroupName); 704 DE->EndFunction(); 705 } else { 706 DE->EndFunction(); 707 } 708 } 709 MMI->EndFunction(); 710 711 // Print out jump tables referenced by the function. 712 EmitJumpTableInfo(); 713 714 OutStreamer.AddBlankLine(); 715} 716 717/// getDebugValueLocation - Get location information encoded by DBG_VALUE 718/// operands. 719MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const { 720 // Target specific DBG_VALUE instructions are handled by each target. 721 return MachineLocation(); 722} 723 724bool AsmPrinter::doFinalization(Module &M) { 725 // Emit global variables. 726 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 727 I != E; ++I) 728 EmitGlobalVariable(I); 729 730 // Finalize debug and EH information. 731 if (DE) { 732 if (TimePassesIsEnabled) { 733 NamedRegionTimer T(EHTimerName, DWARFGroupName); 734 DE->EndModule(); 735 } else { 736 DE->EndModule(); 737 } 738 delete DE; DE = 0; 739 } 740 if (DD) { 741 if (TimePassesIsEnabled) { 742 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 743 DD->endModule(); 744 } else { 745 DD->endModule(); 746 } 747 delete DD; DD = 0; 748 } 749 750 // If the target wants to know about weak references, print them all. 751 if (MAI->getWeakRefDirective()) { 752 // FIXME: This is not lazy, it would be nice to only print weak references 753 // to stuff that is actually used. Note that doing so would require targets 754 // to notice uses in operands (due to constant exprs etc). This should 755 // happen with the MC stuff eventually. 756 757 // Print out module-level global variables here. 758 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 759 I != E; ++I) { 760 if (!I->hasExternalWeakLinkage()) continue; 761 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 762 } 763 764 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 765 if (!I->hasExternalWeakLinkage()) continue; 766 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 767 } 768 } 769 770 if (MAI->hasSetDirective()) { 771 OutStreamer.AddBlankLine(); 772 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 773 I != E; ++I) { 774 MCSymbol *Name = Mang->getSymbol(I); 775 776 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 777 MCSymbol *Target = Mang->getSymbol(GV); 778 779 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 780 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 781 else if (I->hasWeakLinkage()) 782 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 783 else 784 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 785 786 EmitVisibility(Name, I->getVisibility()); 787 788 // Emit the directives as assignments aka .set: 789 OutStreamer.EmitAssignment(Name, 790 MCSymbolRefExpr::Create(Target, OutContext)); 791 } 792 } 793 794 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 795 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 796 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 797 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 798 MP->finishAssembly(*this); 799 800 // If we don't have any trampolines, then we don't require stack memory 801 // to be executable. Some targets have a directive to declare this. 802 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 803 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 804 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 805 OutStreamer.SwitchSection(S); 806 807 // Allow the target to emit any magic that it wants at the end of the file, 808 // after everything else has gone out. 809 EmitEndOfAsmFile(M); 810 811 delete Mang; Mang = 0; 812 MMI = 0; 813 814 OutStreamer.Finish(); 815 return false; 816} 817 818void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 819 this->MF = &MF; 820 // Get the function symbol. 821 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 822 823 if (isVerbose()) 824 LI = &getAnalysis<MachineLoopInfo>(); 825} 826 827namespace { 828 // SectionCPs - Keep track the alignment, constpool entries per Section. 829 struct SectionCPs { 830 const MCSection *S; 831 unsigned Alignment; 832 SmallVector<unsigned, 4> CPEs; 833 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 834 }; 835} 836 837/// EmitConstantPool - Print to the current output stream assembly 838/// representations of the constants in the constant pool MCP. This is 839/// used to print out constants which have been "spilled to memory" by 840/// the code generator. 841/// 842void AsmPrinter::EmitConstantPool() { 843 const MachineConstantPool *MCP = MF->getConstantPool(); 844 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 845 if (CP.empty()) return; 846 847 // Calculate sections for constant pool entries. We collect entries to go into 848 // the same section together to reduce amount of section switch statements. 849 SmallVector<SectionCPs, 4> CPSections; 850 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 851 const MachineConstantPoolEntry &CPE = CP[i]; 852 unsigned Align = CPE.getAlignment(); 853 854 SectionKind Kind; 855 switch (CPE.getRelocationInfo()) { 856 default: llvm_unreachable("Unknown section kind"); 857 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 858 case 1: 859 Kind = SectionKind::getReadOnlyWithRelLocal(); 860 break; 861 case 0: 862 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 863 case 4: Kind = SectionKind::getMergeableConst4(); break; 864 case 8: Kind = SectionKind::getMergeableConst8(); break; 865 case 16: Kind = SectionKind::getMergeableConst16();break; 866 default: Kind = SectionKind::getMergeableConst(); break; 867 } 868 } 869 870 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 871 872 // The number of sections are small, just do a linear search from the 873 // last section to the first. 874 bool Found = false; 875 unsigned SecIdx = CPSections.size(); 876 while (SecIdx != 0) { 877 if (CPSections[--SecIdx].S == S) { 878 Found = true; 879 break; 880 } 881 } 882 if (!Found) { 883 SecIdx = CPSections.size(); 884 CPSections.push_back(SectionCPs(S, Align)); 885 } 886 887 if (Align > CPSections[SecIdx].Alignment) 888 CPSections[SecIdx].Alignment = Align; 889 CPSections[SecIdx].CPEs.push_back(i); 890 } 891 892 // Now print stuff into the calculated sections. 893 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 894 OutStreamer.SwitchSection(CPSections[i].S); 895 EmitAlignment(Log2_32(CPSections[i].Alignment)); 896 897 unsigned Offset = 0; 898 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 899 unsigned CPI = CPSections[i].CPEs[j]; 900 MachineConstantPoolEntry CPE = CP[CPI]; 901 902 // Emit inter-object padding for alignment. 903 unsigned AlignMask = CPE.getAlignment() - 1; 904 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 905 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 906 907 const Type *Ty = CPE.getType(); 908 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 909 910 // Emit the label with a comment on it. 911 if (isVerbose()) { 912 OutStreamer.GetCommentOS() << "constant pool "; 913 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(), 914 MF->getFunction()->getParent()); 915 OutStreamer.GetCommentOS() << '\n'; 916 } 917 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 918 919 if (CPE.isMachineConstantPoolEntry()) 920 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 921 else 922 EmitGlobalConstant(CPE.Val.ConstVal); 923 } 924 } 925} 926 927/// EmitJumpTableInfo - Print assembly representations of the jump tables used 928/// by the current function to the current output stream. 929/// 930void AsmPrinter::EmitJumpTableInfo() { 931 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 932 if (MJTI == 0) return; 933 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 934 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 935 if (JT.empty()) return; 936 937 // Pick the directive to use to print the jump table entries, and switch to 938 // the appropriate section. 939 const Function *F = MF->getFunction(); 940 bool JTInDiffSection = false; 941 if (// In PIC mode, we need to emit the jump table to the same section as the 942 // function body itself, otherwise the label differences won't make sense. 943 // FIXME: Need a better predicate for this: what about custom entries? 944 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 945 // We should also do if the section name is NULL or function is declared 946 // in discardable section 947 // FIXME: this isn't the right predicate, should be based on the MCSection 948 // for the function. 949 F->isWeakForLinker()) { 950 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 951 } else { 952 // Otherwise, drop it in the readonly section. 953 const MCSection *ReadOnlySection = 954 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 955 OutStreamer.SwitchSection(ReadOnlySection); 956 JTInDiffSection = true; 957 } 958 959 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 960 961 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 962 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 963 964 // If this jump table was deleted, ignore it. 965 if (JTBBs.empty()) continue; 966 967 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 968 // .set directive for each unique entry. This reduces the number of 969 // relocations the assembler will generate for the jump table. 970 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 971 MAI->hasSetDirective()) { 972 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 973 const TargetLowering *TLI = TM.getTargetLowering(); 974 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 975 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 976 const MachineBasicBlock *MBB = JTBBs[ii]; 977 if (!EmittedSets.insert(MBB)) continue; 978 979 // .set LJTSet, LBB32-base 980 const MCExpr *LHS = 981 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 982 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 983 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 984 } 985 } 986 987 // On some targets (e.g. Darwin) we want to emit two consequtive labels 988 // before each jump table. The first label is never referenced, but tells 989 // the assembler and linker the extents of the jump table object. The 990 // second label is actually referenced by the code. 991 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 992 // FIXME: This doesn't have to have any specific name, just any randomly 993 // named and numbered 'l' label would work. Simplify GetJTISymbol. 994 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 995 996 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 997 998 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 999 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1000 } 1001} 1002 1003/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1004/// current stream. 1005void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1006 const MachineBasicBlock *MBB, 1007 unsigned UID) const { 1008 const MCExpr *Value = 0; 1009 switch (MJTI->getEntryKind()) { 1010 case MachineJumpTableInfo::EK_Inline: 1011 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1012 case MachineJumpTableInfo::EK_Custom32: 1013 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1014 OutContext); 1015 break; 1016 case MachineJumpTableInfo::EK_BlockAddress: 1017 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1018 // .word LBB123 1019 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1020 break; 1021 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1022 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1023 // with a relocation as gp-relative, e.g.: 1024 // .gprel32 LBB123 1025 MCSymbol *MBBSym = MBB->getSymbol(); 1026 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1027 return; 1028 } 1029 1030 case MachineJumpTableInfo::EK_LabelDifference32: { 1031 // EK_LabelDifference32 - Each entry is the address of the block minus 1032 // the address of the jump table. This is used for PIC jump tables where 1033 // gprel32 is not supported. e.g.: 1034 // .word LBB123 - LJTI1_2 1035 // If the .set directive is supported, this is emitted as: 1036 // .set L4_5_set_123, LBB123 - LJTI1_2 1037 // .word L4_5_set_123 1038 1039 // If we have emitted set directives for the jump table entries, print 1040 // them rather than the entries themselves. If we're emitting PIC, then 1041 // emit the table entries as differences between two text section labels. 1042 if (MAI->hasSetDirective()) { 1043 // If we used .set, reference the .set's symbol. 1044 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1045 OutContext); 1046 break; 1047 } 1048 // Otherwise, use the difference as the jump table entry. 1049 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1050 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1051 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1052 break; 1053 } 1054 } 1055 1056 assert(Value && "Unknown entry kind!"); 1057 1058 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1059 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1060} 1061 1062 1063/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1064/// special global used by LLVM. If so, emit it and return true, otherwise 1065/// do nothing and return false. 1066bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1067 if (GV->getName() == "llvm.used") { 1068 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1069 EmitLLVMUsedList(GV->getInitializer()); 1070 return true; 1071 } 1072 1073 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1074 if (GV->getSection() == "llvm.metadata" || 1075 GV->hasAvailableExternallyLinkage()) 1076 return true; 1077 1078 if (!GV->hasAppendingLinkage()) return false; 1079 1080 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1081 1082 const TargetData *TD = TM.getTargetData(); 1083 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1084 if (GV->getName() == "llvm.global_ctors") { 1085 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1086 EmitAlignment(Align); 1087 EmitXXStructorList(GV->getInitializer()); 1088 1089 if (TM.getRelocationModel() == Reloc::Static && 1090 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1091 StringRef Sym(".constructors_used"); 1092 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1093 MCSA_Reference); 1094 } 1095 return true; 1096 } 1097 1098 if (GV->getName() == "llvm.global_dtors") { 1099 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1100 EmitAlignment(Align); 1101 EmitXXStructorList(GV->getInitializer()); 1102 1103 if (TM.getRelocationModel() == Reloc::Static && 1104 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1105 StringRef Sym(".destructors_used"); 1106 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1107 MCSA_Reference); 1108 } 1109 return true; 1110 } 1111 1112 return false; 1113} 1114 1115/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1116/// global in the specified llvm.used list for which emitUsedDirectiveFor 1117/// is true, as being used with this directive. 1118void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1119 // Should be an array of 'i8*'. 1120 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1121 if (InitList == 0) return; 1122 1123 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1124 const GlobalValue *GV = 1125 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1126 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1127 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1128 } 1129} 1130 1131/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1132/// function pointers, ignoring the init priority. 1133void AsmPrinter::EmitXXStructorList(Constant *List) { 1134 // Should be an array of '{ int, void ()* }' structs. The first value is the 1135 // init priority, which we ignore. 1136 if (!isa<ConstantArray>(List)) return; 1137 ConstantArray *InitList = cast<ConstantArray>(List); 1138 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1139 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1140 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1141 1142 if (CS->getOperand(1)->isNullValue()) 1143 return; // Found a null terminator, exit printing. 1144 // Emit the function pointer. 1145 EmitGlobalConstant(CS->getOperand(1)); 1146 } 1147} 1148 1149//===--------------------------------------------------------------------===// 1150// Emission and print routines 1151// 1152 1153/// EmitInt8 - Emit a byte directive and value. 1154/// 1155void AsmPrinter::EmitInt8(int Value) const { 1156 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1157} 1158 1159/// EmitInt16 - Emit a short directive and value. 1160/// 1161void AsmPrinter::EmitInt16(int Value) const { 1162 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1163} 1164 1165/// EmitInt32 - Emit a long directive and value. 1166/// 1167void AsmPrinter::EmitInt32(int Value) const { 1168 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1169} 1170 1171/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1172/// in bytes of the directive is specified by Size and Hi/Lo specify the 1173/// labels. This implicitly uses .set if it is available. 1174void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1175 unsigned Size) const { 1176 // Get the Hi-Lo expression. 1177 const MCExpr *Diff = 1178 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1179 MCSymbolRefExpr::Create(Lo, OutContext), 1180 OutContext); 1181 1182 if (!MAI->hasSetDirective()) { 1183 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1184 return; 1185 } 1186 1187 // Otherwise, emit with .set (aka assignment). 1188 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1189 OutStreamer.EmitAssignment(SetLabel, Diff); 1190 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1191} 1192 1193/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1194/// where the size in bytes of the directive is specified by Size and Hi/Lo 1195/// specify the labels. This implicitly uses .set if it is available. 1196void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1197 const MCSymbol *Lo, unsigned Size) 1198 const { 1199 1200 // Emit Hi+Offset - Lo 1201 // Get the Hi+Offset expression. 1202 const MCExpr *Plus = 1203 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1204 MCConstantExpr::Create(Offset, OutContext), 1205 OutContext); 1206 1207 // Get the Hi+Offset-Lo expression. 1208 const MCExpr *Diff = 1209 MCBinaryExpr::CreateSub(Plus, 1210 MCSymbolRefExpr::Create(Lo, OutContext), 1211 OutContext); 1212 1213 if (!MAI->hasSetDirective()) 1214 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1215 else { 1216 // Otherwise, emit with .set (aka assignment). 1217 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1218 OutStreamer.EmitAssignment(SetLabel, Diff); 1219 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1220 } 1221} 1222 1223 1224//===----------------------------------------------------------------------===// 1225 1226// EmitAlignment - Emit an alignment directive to the specified power of 1227// two boundary. For example, if you pass in 3 here, you will get an 8 1228// byte alignment. If a global value is specified, and if that global has 1229// an explicit alignment requested, it will override the alignment request 1230// if required for correctness. 1231// 1232void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1233 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1234 1235 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1236 1237 if (getCurrentSection()->getKind().isText()) 1238 OutStreamer.EmitCodeAlignment(1 << NumBits); 1239 else 1240 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1241} 1242 1243//===----------------------------------------------------------------------===// 1244// Constant emission. 1245//===----------------------------------------------------------------------===// 1246 1247/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1248/// 1249static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1250 MCContext &Ctx = AP.OutContext; 1251 1252 if (CV->isNullValue() || isa<UndefValue>(CV)) 1253 return MCConstantExpr::Create(0, Ctx); 1254 1255 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1256 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1257 1258 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1259 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1260 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1261 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1262 1263 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1264 if (CE == 0) { 1265 llvm_unreachable("Unknown constant value to lower!"); 1266 return MCConstantExpr::Create(0, Ctx); 1267 } 1268 1269 switch (CE->getOpcode()) { 1270 default: 1271 // If the code isn't optimized, there may be outstanding folding 1272 // opportunities. Attempt to fold the expression using TargetData as a 1273 // last resort before giving up. 1274 if (Constant *C = 1275 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1276 if (C != CE) 1277 return LowerConstant(C, AP); 1278#ifndef NDEBUG 1279 CE->dump(); 1280#endif 1281 llvm_unreachable("FIXME: Don't support this constant expr"); 1282 case Instruction::GetElementPtr: { 1283 const TargetData &TD = *AP.TM.getTargetData(); 1284 // Generate a symbolic expression for the byte address 1285 const Constant *PtrVal = CE->getOperand(0); 1286 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1287 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1288 IdxVec.size()); 1289 1290 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1291 if (Offset == 0) 1292 return Base; 1293 1294 // Truncate/sext the offset to the pointer size. 1295 if (TD.getPointerSizeInBits() != 64) { 1296 int SExtAmount = 64-TD.getPointerSizeInBits(); 1297 Offset = (Offset << SExtAmount) >> SExtAmount; 1298 } 1299 1300 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1301 Ctx); 1302 } 1303 1304 case Instruction::Trunc: 1305 // We emit the value and depend on the assembler to truncate the generated 1306 // expression properly. This is important for differences between 1307 // blockaddress labels. Since the two labels are in the same function, it 1308 // is reasonable to treat their delta as a 32-bit value. 1309 // FALL THROUGH. 1310 case Instruction::BitCast: 1311 return LowerConstant(CE->getOperand(0), AP); 1312 1313 case Instruction::IntToPtr: { 1314 const TargetData &TD = *AP.TM.getTargetData(); 1315 // Handle casts to pointers by changing them into casts to the appropriate 1316 // integer type. This promotes constant folding and simplifies this code. 1317 Constant *Op = CE->getOperand(0); 1318 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1319 false/*ZExt*/); 1320 return LowerConstant(Op, AP); 1321 } 1322 1323 case Instruction::PtrToInt: { 1324 const TargetData &TD = *AP.TM.getTargetData(); 1325 // Support only foldable casts to/from pointers that can be eliminated by 1326 // changing the pointer to the appropriately sized integer type. 1327 Constant *Op = CE->getOperand(0); 1328 const Type *Ty = CE->getType(); 1329 1330 const MCExpr *OpExpr = LowerConstant(Op, AP); 1331 1332 // We can emit the pointer value into this slot if the slot is an 1333 // integer slot equal to the size of the pointer. 1334 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1335 return OpExpr; 1336 1337 // Otherwise the pointer is smaller than the resultant integer, mask off 1338 // the high bits so we are sure to get a proper truncation if the input is 1339 // a constant expr. 1340 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1341 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1342 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1343 } 1344 1345 // The MC library also has a right-shift operator, but it isn't consistently 1346 // signed or unsigned between different targets. 1347 case Instruction::Add: 1348 case Instruction::Sub: 1349 case Instruction::Mul: 1350 case Instruction::SDiv: 1351 case Instruction::SRem: 1352 case Instruction::Shl: 1353 case Instruction::And: 1354 case Instruction::Or: 1355 case Instruction::Xor: { 1356 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1357 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1358 switch (CE->getOpcode()) { 1359 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1360 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1361 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1362 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1363 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1364 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1365 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1366 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1367 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1368 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1369 } 1370 } 1371 } 1372} 1373 1374static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1375 AsmPrinter &AP); 1376 1377static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1378 AsmPrinter &AP) { 1379 if (AddrSpace != 0 || !CA->isString()) { 1380 // Not a string. Print the values in successive locations 1381 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1382 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1383 return; 1384 } 1385 1386 // Otherwise, it can be emitted as .ascii. 1387 SmallVector<char, 128> TmpVec; 1388 TmpVec.reserve(CA->getNumOperands()); 1389 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1390 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1391 1392 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1393} 1394 1395static void EmitGlobalConstantVector(const ConstantVector *CV, 1396 unsigned AddrSpace, AsmPrinter &AP) { 1397 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1398 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1399} 1400 1401static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1402 unsigned AddrSpace, AsmPrinter &AP) { 1403 // Print the fields in successive locations. Pad to align if needed! 1404 const TargetData *TD = AP.TM.getTargetData(); 1405 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1406 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1407 uint64_t SizeSoFar = 0; 1408 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1409 const Constant *Field = CS->getOperand(i); 1410 1411 // Check if padding is needed and insert one or more 0s. 1412 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1413 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1414 - Layout->getElementOffset(i)) - FieldSize; 1415 SizeSoFar += FieldSize + PadSize; 1416 1417 // Now print the actual field value. 1418 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1419 1420 // Insert padding - this may include padding to increase the size of the 1421 // current field up to the ABI size (if the struct is not packed) as well 1422 // as padding to ensure that the next field starts at the right offset. 1423 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1424 } 1425 assert(SizeSoFar == Layout->getSizeInBytes() && 1426 "Layout of constant struct may be incorrect!"); 1427} 1428 1429static void EmitGlobalConstantUnion(const ConstantUnion *CU, 1430 unsigned AddrSpace, AsmPrinter &AP) { 1431 const TargetData *TD = AP.TM.getTargetData(); 1432 unsigned Size = TD->getTypeAllocSize(CU->getType()); 1433 1434 const Constant *Contents = CU->getOperand(0); 1435 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType()); 1436 1437 // Print the actually filled part 1438 EmitGlobalConstantImpl(Contents, AddrSpace, AP); 1439 1440 // And pad with enough zeroes 1441 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace); 1442} 1443 1444static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1445 AsmPrinter &AP) { 1446 // FP Constants are printed as integer constants to avoid losing 1447 // precision. 1448 if (CFP->getType()->isDoubleTy()) { 1449 if (AP.isVerbose()) { 1450 double Val = CFP->getValueAPF().convertToDouble(); 1451 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1452 } 1453 1454 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1455 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1456 return; 1457 } 1458 1459 if (CFP->getType()->isFloatTy()) { 1460 if (AP.isVerbose()) { 1461 float Val = CFP->getValueAPF().convertToFloat(); 1462 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1463 } 1464 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1465 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1466 return; 1467 } 1468 1469 if (CFP->getType()->isX86_FP80Ty()) { 1470 // all long double variants are printed as hex 1471 // API needed to prevent premature destruction 1472 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1473 const uint64_t *p = API.getRawData(); 1474 if (AP.isVerbose()) { 1475 // Convert to double so we can print the approximate val as a comment. 1476 APFloat DoubleVal = CFP->getValueAPF(); 1477 bool ignored; 1478 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1479 &ignored); 1480 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1481 << DoubleVal.convertToDouble() << '\n'; 1482 } 1483 1484 if (AP.TM.getTargetData()->isBigEndian()) { 1485 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1486 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1487 } else { 1488 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1489 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1490 } 1491 1492 // Emit the tail padding for the long double. 1493 const TargetData &TD = *AP.TM.getTargetData(); 1494 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1495 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1496 return; 1497 } 1498 1499 assert(CFP->getType()->isPPC_FP128Ty() && 1500 "Floating point constant type not handled"); 1501 // All long double variants are printed as hex 1502 // API needed to prevent premature destruction. 1503 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1504 const uint64_t *p = API.getRawData(); 1505 if (AP.TM.getTargetData()->isBigEndian()) { 1506 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1507 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1508 } else { 1509 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1510 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1511 } 1512} 1513 1514static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1515 unsigned AddrSpace, AsmPrinter &AP) { 1516 const TargetData *TD = AP.TM.getTargetData(); 1517 unsigned BitWidth = CI->getBitWidth(); 1518 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1519 1520 // We don't expect assemblers to support integer data directives 1521 // for more than 64 bits, so we emit the data in at most 64-bit 1522 // quantities at a time. 1523 const uint64_t *RawData = CI->getValue().getRawData(); 1524 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1525 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1526 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1527 } 1528} 1529 1530static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1531 AsmPrinter &AP) { 1532 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1533 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1534 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1535 } 1536 1537 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1538 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1539 switch (Size) { 1540 case 1: 1541 case 2: 1542 case 4: 1543 case 8: 1544 if (AP.isVerbose()) 1545 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1546 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1547 return; 1548 default: 1549 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1550 return; 1551 } 1552 } 1553 1554 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1555 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1556 1557 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1558 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1559 1560 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1561 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1562 1563 if (isa<ConstantPointerNull>(CV)) { 1564 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1565 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1566 return; 1567 } 1568 1569 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV)) 1570 return EmitGlobalConstantUnion(CVU, AddrSpace, AP); 1571 1572 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1573 return EmitGlobalConstantVector(V, AddrSpace, AP); 1574 1575 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1576 // thread the streamer with EmitValue. 1577 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1578 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1579 AddrSpace); 1580} 1581 1582/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1583void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1584 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1585 if (Size) 1586 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1587 else if (MAI->hasSubsectionsViaSymbols()) { 1588 // If the global has zero size, emit a single byte so that two labels don't 1589 // look like they are at the same location. 1590 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1591 } 1592} 1593 1594void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1595 // Target doesn't support this yet! 1596 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1597} 1598 1599void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1600 if (Offset > 0) 1601 OS << '+' << Offset; 1602 else if (Offset < 0) 1603 OS << Offset; 1604} 1605 1606//===----------------------------------------------------------------------===// 1607// Symbol Lowering Routines. 1608//===----------------------------------------------------------------------===// 1609 1610/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1611/// temporary label with the specified stem and unique ID. 1612MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1613 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1614 Name + Twine(ID)); 1615} 1616 1617/// GetTempSymbol - Return an assembler temporary label with the specified 1618/// stem. 1619MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1620 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1621 Name); 1622} 1623 1624 1625MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1626 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1627} 1628 1629MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1630 return MMI->getAddrLabelSymbol(BB); 1631} 1632 1633/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1634MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1635 return OutContext.GetOrCreateSymbol 1636 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1637 + "_" + Twine(CPID)); 1638} 1639 1640/// GetJTISymbol - Return the symbol for the specified jump table entry. 1641MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1642 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1643} 1644 1645/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1646/// FIXME: privatize to AsmPrinter. 1647MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1648 return OutContext.GetOrCreateSymbol 1649 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1650 Twine(UID) + "_set_" + Twine(MBBID)); 1651} 1652 1653/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1654/// global value name as its base, with the specified suffix, and where the 1655/// symbol is forced to have private linkage if ForcePrivate is true. 1656MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1657 StringRef Suffix, 1658 bool ForcePrivate) const { 1659 SmallString<60> NameStr; 1660 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1661 NameStr.append(Suffix.begin(), Suffix.end()); 1662 return OutContext.GetOrCreateSymbol(NameStr.str()); 1663} 1664 1665/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1666/// ExternalSymbol. 1667MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1668 SmallString<60> NameStr; 1669 Mang->getNameWithPrefix(NameStr, Sym); 1670 return OutContext.GetOrCreateSymbol(NameStr.str()); 1671} 1672 1673 1674 1675/// PrintParentLoopComment - Print comments about parent loops of this one. 1676static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1677 unsigned FunctionNumber) { 1678 if (Loop == 0) return; 1679 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1680 OS.indent(Loop->getLoopDepth()*2) 1681 << "Parent Loop BB" << FunctionNumber << "_" 1682 << Loop->getHeader()->getNumber() 1683 << " Depth=" << Loop->getLoopDepth() << '\n'; 1684} 1685 1686 1687/// PrintChildLoopComment - Print comments about child loops within 1688/// the loop for this basic block, with nesting. 1689static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1690 unsigned FunctionNumber) { 1691 // Add child loop information 1692 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1693 OS.indent((*CL)->getLoopDepth()*2) 1694 << "Child Loop BB" << FunctionNumber << "_" 1695 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1696 << '\n'; 1697 PrintChildLoopComment(OS, *CL, FunctionNumber); 1698 } 1699} 1700 1701/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1702static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1703 const MachineLoopInfo *LI, 1704 const AsmPrinter &AP) { 1705 // Add loop depth information 1706 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1707 if (Loop == 0) return; 1708 1709 MachineBasicBlock *Header = Loop->getHeader(); 1710 assert(Header && "No header for loop"); 1711 1712 // If this block is not a loop header, just print out what is the loop header 1713 // and return. 1714 if (Header != &MBB) { 1715 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1716 Twine(AP.getFunctionNumber())+"_" + 1717 Twine(Loop->getHeader()->getNumber())+ 1718 " Depth="+Twine(Loop->getLoopDepth())); 1719 return; 1720 } 1721 1722 // Otherwise, it is a loop header. Print out information about child and 1723 // parent loops. 1724 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1725 1726 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1727 1728 OS << "=>"; 1729 OS.indent(Loop->getLoopDepth()*2-2); 1730 1731 OS << "This "; 1732 if (Loop->empty()) 1733 OS << "Inner "; 1734 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1735 1736 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1737} 1738 1739 1740/// EmitBasicBlockStart - This method prints the label for the specified 1741/// MachineBasicBlock, an alignment (if present) and a comment describing 1742/// it if appropriate. 1743void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1744 // Emit an alignment directive for this block, if needed. 1745 if (unsigned Align = MBB->getAlignment()) 1746 EmitAlignment(Log2_32(Align)); 1747 1748 // If the block has its address taken, emit any labels that were used to 1749 // reference the block. It is possible that there is more than one label 1750 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1751 // the references were generated. 1752 if (MBB->hasAddressTaken()) { 1753 const BasicBlock *BB = MBB->getBasicBlock(); 1754 if (isVerbose()) 1755 OutStreamer.AddComment("Block address taken"); 1756 1757 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1758 1759 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1760 OutStreamer.EmitLabel(Syms[i]); 1761 } 1762 1763 // Print the main label for the block. 1764 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1765 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1766 if (const BasicBlock *BB = MBB->getBasicBlock()) 1767 if (BB->hasName()) 1768 OutStreamer.AddComment("%" + BB->getName()); 1769 1770 EmitBasicBlockLoopComments(*MBB, LI, *this); 1771 1772 // NOTE: Want this comment at start of line, don't emit with AddComment. 1773 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1774 Twine(MBB->getNumber()) + ":"); 1775 } 1776 } else { 1777 if (isVerbose()) { 1778 if (const BasicBlock *BB = MBB->getBasicBlock()) 1779 if (BB->hasName()) 1780 OutStreamer.AddComment("%" + BB->getName()); 1781 EmitBasicBlockLoopComments(*MBB, LI, *this); 1782 } 1783 1784 OutStreamer.EmitLabel(MBB->getSymbol()); 1785 } 1786} 1787 1788void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1789 MCSymbolAttr Attr = MCSA_Invalid; 1790 1791 switch (Visibility) { 1792 default: break; 1793 case GlobalValue::HiddenVisibility: 1794 Attr = MAI->getHiddenVisibilityAttr(); 1795 break; 1796 case GlobalValue::ProtectedVisibility: 1797 Attr = MAI->getProtectedVisibilityAttr(); 1798 break; 1799 } 1800 1801 if (Attr != MCSA_Invalid) 1802 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1803} 1804 1805/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1806/// exactly one predecessor and the control transfer mechanism between 1807/// the predecessor and this block is a fall-through. 1808bool AsmPrinter:: 1809isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1810 // If this is a landing pad, it isn't a fall through. If it has no preds, 1811 // then nothing falls through to it. 1812 if (MBB->isLandingPad() || MBB->pred_empty()) 1813 return false; 1814 1815 // If there isn't exactly one predecessor, it can't be a fall through. 1816 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1817 ++PI2; 1818 if (PI2 != MBB->pred_end()) 1819 return false; 1820 1821 // The predecessor has to be immediately before this block. 1822 const MachineBasicBlock *Pred = *PI; 1823 1824 if (!Pred->isLayoutSuccessor(MBB)) 1825 return false; 1826 1827 // If the block is completely empty, then it definitely does fall through. 1828 if (Pred->empty()) 1829 return true; 1830 1831 // Otherwise, check the last instruction. 1832 const MachineInstr &LastInst = Pred->back(); 1833 return !LastInst.getDesc().isBarrier(); 1834} 1835 1836 1837 1838GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1839 if (!S->usesMetadata()) 1840 return 0; 1841 1842 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1843 gcp_map_type::iterator GCPI = GCMap.find(S); 1844 if (GCPI != GCMap.end()) 1845 return GCPI->second; 1846 1847 const char *Name = S->getName().c_str(); 1848 1849 for (GCMetadataPrinterRegistry::iterator 1850 I = GCMetadataPrinterRegistry::begin(), 1851 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1852 if (strcmp(Name, I->getName()) == 0) { 1853 GCMetadataPrinter *GMP = I->instantiate(); 1854 GMP->S = S; 1855 GCMap.insert(std::make_pair(S, GMP)); 1856 return GMP; 1857 } 1858 1859 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1860 return 0; 1861} 1862 1863