AsmPrinter.cpp revision f01b62dabc0372b5cf4525272fba263e6589f066
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 OutStreamer.SwitchSection(TheSection); 315 316 EmitLinkage(GV->getLinkage(), GVSym); 317 EmitAlignment(AlignLog, GV); 318 319 if (isVerbose()) { 320 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 321 /*PrintType=*/false, GV->getParent()); 322 OutStreamer.GetCommentOS() << '\n'; 323 } 324 OutStreamer.EmitLabel(GVSym); 325 326 EmitGlobalConstant(GV->getInitializer()); 327 328 if (MAI->hasDotTypeDotSizeDirective()) 329 // .size foo, 42 330 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 331 332 OutStreamer.AddBlankLine(); 333} 334 335/// EmitFunctionHeader - This method emits the header for the current 336/// function. 337void AsmPrinter::EmitFunctionHeader() { 338 // Print out constants referenced by the function 339 EmitConstantPool(); 340 341 // Print the 'header' of function. 342 const Function *F = MF->getFunction(); 343 344 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 345 EmitVisibility(CurrentFnSym, F->getVisibility()); 346 347 EmitLinkage(F->getLinkage(), CurrentFnSym); 348 EmitAlignment(MF->getAlignment(), F); 349 350 if (MAI->hasDotTypeDotSizeDirective()) 351 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 352 353 if (isVerbose()) { 354 WriteAsOperand(OutStreamer.GetCommentOS(), F, 355 /*PrintType=*/false, F->getParent()); 356 OutStreamer.GetCommentOS() << '\n'; 357 } 358 359 // Emit the CurrentFnSym. This is a virtual function to allow targets to 360 // do their wild and crazy things as required. 361 EmitFunctionEntryLabel(); 362 363 // If the function had address-taken blocks that got deleted, then we have 364 // references to the dangling symbols. Emit them at the start of the function 365 // so that we don't get references to undefined symbols. 366 std::vector<MCSymbol*> DeadBlockSyms; 367 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 368 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 369 OutStreamer.AddComment("Address taken block that was later removed"); 370 OutStreamer.EmitLabel(DeadBlockSyms[i]); 371 } 372 373 // Add some workaround for linkonce linkage on Cygwin\MinGW. 374 if (MAI->getLinkOnceDirective() != 0 && 375 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 376 // FIXME: What is this? 377 MCSymbol *FakeStub = 378 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 379 CurrentFnSym->getName()); 380 OutStreamer.EmitLabel(FakeStub); 381 } 382 383 // Emit pre-function debug and/or EH information. 384 if (DE) { 385 if (TimePassesIsEnabled) { 386 NamedRegionTimer T(EHTimerName, DWARFGroupName); 387 DE->BeginFunction(MF); 388 } else { 389 DE->BeginFunction(MF); 390 } 391 } 392 if (DD) { 393 if (TimePassesIsEnabled) { 394 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 395 DD->beginFunction(MF); 396 } else { 397 DD->beginFunction(MF); 398 } 399 } 400} 401 402/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 403/// function. This can be overridden by targets as required to do custom stuff. 404void AsmPrinter::EmitFunctionEntryLabel() { 405 // The function label could have already been emitted if two symbols end up 406 // conflicting due to asm renaming. Detect this and emit an error. 407 if (CurrentFnSym->isUndefined()) 408 return OutStreamer.EmitLabel(CurrentFnSym); 409 410 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 411 "' label emitted multiple times to assembly file"); 412} 413 414 415/// EmitComments - Pretty-print comments for instructions. 416static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 417 const MachineFunction *MF = MI.getParent()->getParent(); 418 const TargetMachine &TM = MF->getTarget(); 419 420 DebugLoc DL = MI.getDebugLoc(); 421 if (!DL.isUnknown()) { // Print source line info. 422 DIScope Scope(DL.getScope(MF->getFunction()->getContext())); 423 // Omit the directory, because it's likely to be long and uninteresting. 424 if (Scope.Verify()) 425 CommentOS << Scope.getFilename(); 426 else 427 CommentOS << "<unknown>"; 428 CommentOS << ':' << DL.getLine(); 429 if (DL.getCol() != 0) 430 CommentOS << ':' << DL.getCol(); 431 CommentOS << '\n'; 432 } 433 434 // Check for spills and reloads 435 int FI; 436 437 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 438 439 // We assume a single instruction only has a spill or reload, not 440 // both. 441 const MachineMemOperand *MMO; 442 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 443 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 444 MMO = *MI.memoperands_begin(); 445 CommentOS << MMO->getSize() << "-byte Reload\n"; 446 } 447 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 448 if (FrameInfo->isSpillSlotObjectIndex(FI)) 449 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 450 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 451 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 452 MMO = *MI.memoperands_begin(); 453 CommentOS << MMO->getSize() << "-byte Spill\n"; 454 } 455 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 456 if (FrameInfo->isSpillSlotObjectIndex(FI)) 457 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 458 } 459 460 // Check for spill-induced copies 461 unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx; 462 if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg, 463 SrcSubIdx, DstSubIdx)) { 464 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 465 CommentOS << " Reload Reuse\n"; 466 } 467} 468 469/// EmitImplicitDef - This method emits the specified machine instruction 470/// that is an implicit def. 471static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 472 unsigned RegNo = MI->getOperand(0).getReg(); 473 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 474 AP.TM.getRegisterInfo()->getName(RegNo)); 475 AP.OutStreamer.AddBlankLine(); 476} 477 478static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 479 std::string Str = "kill:"; 480 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 481 const MachineOperand &Op = MI->getOperand(i); 482 assert(Op.isReg() && "KILL instruction must have only register operands"); 483 Str += ' '; 484 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 485 Str += (Op.isDef() ? "<def>" : "<kill>"); 486 } 487 AP.OutStreamer.AddComment(Str); 488 AP.OutStreamer.AddBlankLine(); 489} 490 491/// EmitDebugValueComment - This method handles the target-independent form 492/// of DBG_VALUE, returning true if it was able to do so. A false return 493/// means the target will need to handle MI in EmitInstruction. 494static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 495 // This code handles only the 3-operand target-independent form. 496 if (MI->getNumOperands() != 3) 497 return false; 498 499 SmallString<128> Str; 500 raw_svector_ostream OS(Str); 501 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 502 503 // cast away const; DIetc do not take const operands for some reason. 504 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 505 if (V.getContext().isSubprogram()) 506 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 507 OS << V.getName() << " <- "; 508 509 // Register or immediate value. Register 0 means undef. 510 if (MI->getOperand(0).isFPImm()) { 511 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 512 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 513 OS << (double)APF.convertToFloat(); 514 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 515 OS << APF.convertToDouble(); 516 } else { 517 // There is no good way to print long double. Convert a copy to 518 // double. Ah well, it's only a comment. 519 bool ignored; 520 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 521 &ignored); 522 OS << "(long double) " << APF.convertToDouble(); 523 } 524 } else if (MI->getOperand(0).isImm()) { 525 OS << MI->getOperand(0).getImm(); 526 } else { 527 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 528 if (MI->getOperand(0).getReg() == 0) { 529 // Suppress offset, it is not meaningful here. 530 OS << "undef"; 531 // NOTE: Want this comment at start of line, don't emit with AddComment. 532 AP.OutStreamer.EmitRawText(OS.str()); 533 return true; 534 } 535 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 536 } 537 538 OS << '+' << MI->getOperand(1).getImm(); 539 // NOTE: Want this comment at start of line, don't emit with AddComment. 540 AP.OutStreamer.EmitRawText(OS.str()); 541 return true; 542} 543 544/// EmitFunctionBody - This method emits the body and trailer for a 545/// function. 546void AsmPrinter::EmitFunctionBody() { 547 // Emit target-specific gunk before the function body. 548 EmitFunctionBodyStart(); 549 550 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 551 552 // Print out code for the function. 553 bool HasAnyRealCode = false; 554 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 555 I != E; ++I) { 556 // Print a label for the basic block. 557 EmitBasicBlockStart(I); 558 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 559 II != IE; ++II) { 560 // Print the assembly for the instruction. 561 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 562 !II->isDebugValue()) { 563 HasAnyRealCode = true; 564 ++EmittedInsts; 565 } 566 567 if (ShouldPrintDebugScopes) { 568 if (TimePassesIsEnabled) { 569 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 570 DD->beginScope(II); 571 } else { 572 DD->beginScope(II); 573 } 574 } 575 576 if (isVerbose()) 577 EmitComments(*II, OutStreamer.GetCommentOS()); 578 579 switch (II->getOpcode()) { 580 case TargetOpcode::DBG_LABEL: 581 case TargetOpcode::EH_LABEL: 582 case TargetOpcode::GC_LABEL: 583 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 584 break; 585 case TargetOpcode::INLINEASM: 586 EmitInlineAsm(II); 587 break; 588 case TargetOpcode::DBG_VALUE: 589 if (isVerbose()) { 590 if (!EmitDebugValueComment(II, *this)) 591 EmitInstruction(II); 592 } 593 break; 594 case TargetOpcode::IMPLICIT_DEF: 595 if (isVerbose()) EmitImplicitDef(II, *this); 596 break; 597 case TargetOpcode::KILL: 598 if (isVerbose()) EmitKill(II, *this); 599 break; 600 default: 601 EmitInstruction(II); 602 break; 603 } 604 605 if (ShouldPrintDebugScopes) { 606 if (TimePassesIsEnabled) { 607 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 608 DD->endScope(II); 609 } else { 610 DD->endScope(II); 611 } 612 } 613 } 614 } 615 616 // If the function is empty and the object file uses .subsections_via_symbols, 617 // then we need to emit *something* to the function body to prevent the 618 // labels from collapsing together. Just emit a noop. 619 if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) { 620 MCInst Noop; 621 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 622 if (Noop.getOpcode()) { 623 OutStreamer.AddComment("avoids zero-length function"); 624 OutStreamer.EmitInstruction(Noop); 625 } else // Target not mc-ized yet. 626 OutStreamer.EmitRawText(StringRef("\tnop\n")); 627 } 628 629 // Emit target-specific gunk after the function body. 630 EmitFunctionBodyEnd(); 631 632 // If the target wants a .size directive for the size of the function, emit 633 // it. 634 if (MAI->hasDotTypeDotSizeDirective()) { 635 // Create a symbol for the end of function, so we can get the size as 636 // difference between the function label and the temp label. 637 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 638 OutStreamer.EmitLabel(FnEndLabel); 639 640 const MCExpr *SizeExp = 641 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 642 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 643 OutContext); 644 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 645 } 646 647 // Emit post-function debug information. 648 if (DD) { 649 if (TimePassesIsEnabled) { 650 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 651 DD->endFunction(MF); 652 } else { 653 DD->endFunction(MF); 654 } 655 } 656 if (DE) { 657 if (TimePassesIsEnabled) { 658 NamedRegionTimer T(EHTimerName, DWARFGroupName); 659 DE->EndFunction(); 660 } else { 661 DE->EndFunction(); 662 } 663 } 664 MMI->EndFunction(); 665 666 // Print out jump tables referenced by the function. 667 EmitJumpTableInfo(); 668 669 OutStreamer.AddBlankLine(); 670} 671 672/// getDebugValueLocation - Get location information encoded by DBG_VALUE 673/// operands. 674MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const { 675 // Target specific DBG_VALUE instructions are handled by each target. 676 return MachineLocation(); 677} 678 679bool AsmPrinter::doFinalization(Module &M) { 680 // Emit global variables. 681 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 682 I != E; ++I) 683 EmitGlobalVariable(I); 684 685 // Finalize debug and EH information. 686 if (DE) { 687 if (TimePassesIsEnabled) { 688 NamedRegionTimer T(EHTimerName, DWARFGroupName); 689 DE->EndModule(); 690 } else { 691 DE->EndModule(); 692 } 693 delete DE; DE = 0; 694 } 695 if (DD) { 696 if (TimePassesIsEnabled) { 697 NamedRegionTimer T(DbgTimerName, DWARFGroupName); 698 DD->endModule(); 699 } else { 700 DD->endModule(); 701 } 702 delete DD; DD = 0; 703 } 704 705 // If the target wants to know about weak references, print them all. 706 if (MAI->getWeakRefDirective()) { 707 // FIXME: This is not lazy, it would be nice to only print weak references 708 // to stuff that is actually used. Note that doing so would require targets 709 // to notice uses in operands (due to constant exprs etc). This should 710 // happen with the MC stuff eventually. 711 712 // Print out module-level global variables here. 713 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 714 I != E; ++I) { 715 if (!I->hasExternalWeakLinkage()) continue; 716 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 717 } 718 719 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 720 if (!I->hasExternalWeakLinkage()) continue; 721 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 722 } 723 } 724 725 if (MAI->hasSetDirective()) { 726 OutStreamer.AddBlankLine(); 727 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 728 I != E; ++I) { 729 MCSymbol *Name = Mang->getSymbol(I); 730 731 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 732 MCSymbol *Target = Mang->getSymbol(GV); 733 734 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 735 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 736 else if (I->hasWeakLinkage()) 737 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 738 else 739 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 740 741 EmitVisibility(Name, I->getVisibility()); 742 743 // Emit the directives as assignments aka .set: 744 OutStreamer.EmitAssignment(Name, 745 MCSymbolRefExpr::Create(Target, OutContext)); 746 } 747 } 748 749 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 750 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 751 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 752 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 753 MP->finishAssembly(*this); 754 755 // If we don't have any trampolines, then we don't require stack memory 756 // to be executable. Some targets have a directive to declare this. 757 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 758 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 759 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 760 OutStreamer.SwitchSection(S); 761 762 // Allow the target to emit any magic that it wants at the end of the file, 763 // after everything else has gone out. 764 EmitEndOfAsmFile(M); 765 766 delete Mang; Mang = 0; 767 MMI = 0; 768 769 OutStreamer.Finish(); 770 return false; 771} 772 773void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 774 this->MF = &MF; 775 // Get the function symbol. 776 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 777 778 if (isVerbose()) 779 LI = &getAnalysis<MachineLoopInfo>(); 780} 781 782namespace { 783 // SectionCPs - Keep track the alignment, constpool entries per Section. 784 struct SectionCPs { 785 const MCSection *S; 786 unsigned Alignment; 787 SmallVector<unsigned, 4> CPEs; 788 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 789 }; 790} 791 792/// EmitConstantPool - Print to the current output stream assembly 793/// representations of the constants in the constant pool MCP. This is 794/// used to print out constants which have been "spilled to memory" by 795/// the code generator. 796/// 797void AsmPrinter::EmitConstantPool() { 798 const MachineConstantPool *MCP = MF->getConstantPool(); 799 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 800 if (CP.empty()) return; 801 802 // Calculate sections for constant pool entries. We collect entries to go into 803 // the same section together to reduce amount of section switch statements. 804 SmallVector<SectionCPs, 4> CPSections; 805 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 806 const MachineConstantPoolEntry &CPE = CP[i]; 807 unsigned Align = CPE.getAlignment(); 808 809 SectionKind Kind; 810 switch (CPE.getRelocationInfo()) { 811 default: llvm_unreachable("Unknown section kind"); 812 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 813 case 1: 814 Kind = SectionKind::getReadOnlyWithRelLocal(); 815 break; 816 case 0: 817 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 818 case 4: Kind = SectionKind::getMergeableConst4(); break; 819 case 8: Kind = SectionKind::getMergeableConst8(); break; 820 case 16: Kind = SectionKind::getMergeableConst16();break; 821 default: Kind = SectionKind::getMergeableConst(); break; 822 } 823 } 824 825 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 826 827 // The number of sections are small, just do a linear search from the 828 // last section to the first. 829 bool Found = false; 830 unsigned SecIdx = CPSections.size(); 831 while (SecIdx != 0) { 832 if (CPSections[--SecIdx].S == S) { 833 Found = true; 834 break; 835 } 836 } 837 if (!Found) { 838 SecIdx = CPSections.size(); 839 CPSections.push_back(SectionCPs(S, Align)); 840 } 841 842 if (Align > CPSections[SecIdx].Alignment) 843 CPSections[SecIdx].Alignment = Align; 844 CPSections[SecIdx].CPEs.push_back(i); 845 } 846 847 // Now print stuff into the calculated sections. 848 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 849 OutStreamer.SwitchSection(CPSections[i].S); 850 EmitAlignment(Log2_32(CPSections[i].Alignment)); 851 852 unsigned Offset = 0; 853 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 854 unsigned CPI = CPSections[i].CPEs[j]; 855 MachineConstantPoolEntry CPE = CP[CPI]; 856 857 // Emit inter-object padding for alignment. 858 unsigned AlignMask = CPE.getAlignment() - 1; 859 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 860 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 861 862 const Type *Ty = CPE.getType(); 863 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 864 865 // Emit the label with a comment on it. 866 if (isVerbose()) { 867 OutStreamer.GetCommentOS() << "constant pool "; 868 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(), 869 MF->getFunction()->getParent()); 870 OutStreamer.GetCommentOS() << '\n'; 871 } 872 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 873 874 if (CPE.isMachineConstantPoolEntry()) 875 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 876 else 877 EmitGlobalConstant(CPE.Val.ConstVal); 878 } 879 } 880} 881 882/// EmitJumpTableInfo - Print assembly representations of the jump tables used 883/// by the current function to the current output stream. 884/// 885void AsmPrinter::EmitJumpTableInfo() { 886 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 887 if (MJTI == 0) return; 888 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 889 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 890 if (JT.empty()) return; 891 892 // Pick the directive to use to print the jump table entries, and switch to 893 // the appropriate section. 894 const Function *F = MF->getFunction(); 895 bool JTInDiffSection = false; 896 if (// In PIC mode, we need to emit the jump table to the same section as the 897 // function body itself, otherwise the label differences won't make sense. 898 // FIXME: Need a better predicate for this: what about custom entries? 899 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 900 // We should also do if the section name is NULL or function is declared 901 // in discardable section 902 // FIXME: this isn't the right predicate, should be based on the MCSection 903 // for the function. 904 F->isWeakForLinker()) { 905 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 906 } else { 907 // Otherwise, drop it in the readonly section. 908 const MCSection *ReadOnlySection = 909 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 910 OutStreamer.SwitchSection(ReadOnlySection); 911 JTInDiffSection = true; 912 } 913 914 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 915 916 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 917 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 918 919 // If this jump table was deleted, ignore it. 920 if (JTBBs.empty()) continue; 921 922 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 923 // .set directive for each unique entry. This reduces the number of 924 // relocations the assembler will generate for the jump table. 925 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 926 MAI->hasSetDirective()) { 927 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 928 const TargetLowering *TLI = TM.getTargetLowering(); 929 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 930 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 931 const MachineBasicBlock *MBB = JTBBs[ii]; 932 if (!EmittedSets.insert(MBB)) continue; 933 934 // .set LJTSet, LBB32-base 935 const MCExpr *LHS = 936 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 937 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 938 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 939 } 940 } 941 942 // On some targets (e.g. Darwin) we want to emit two consequtive labels 943 // before each jump table. The first label is never referenced, but tells 944 // the assembler and linker the extents of the jump table object. The 945 // second label is actually referenced by the code. 946 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 947 // FIXME: This doesn't have to have any specific name, just any randomly 948 // named and numbered 'l' label would work. Simplify GetJTISymbol. 949 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 950 951 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 952 953 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 954 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 955 } 956} 957 958/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 959/// current stream. 960void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 961 const MachineBasicBlock *MBB, 962 unsigned UID) const { 963 const MCExpr *Value = 0; 964 switch (MJTI->getEntryKind()) { 965 case MachineJumpTableInfo::EK_Inline: 966 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 967 case MachineJumpTableInfo::EK_Custom32: 968 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 969 OutContext); 970 break; 971 case MachineJumpTableInfo::EK_BlockAddress: 972 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 973 // .word LBB123 974 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 975 break; 976 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 977 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 978 // with a relocation as gp-relative, e.g.: 979 // .gprel32 LBB123 980 MCSymbol *MBBSym = MBB->getSymbol(); 981 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 982 return; 983 } 984 985 case MachineJumpTableInfo::EK_LabelDifference32: { 986 // EK_LabelDifference32 - Each entry is the address of the block minus 987 // the address of the jump table. This is used for PIC jump tables where 988 // gprel32 is not supported. e.g.: 989 // .word LBB123 - LJTI1_2 990 // If the .set directive is supported, this is emitted as: 991 // .set L4_5_set_123, LBB123 - LJTI1_2 992 // .word L4_5_set_123 993 994 // If we have emitted set directives for the jump table entries, print 995 // them rather than the entries themselves. If we're emitting PIC, then 996 // emit the table entries as differences between two text section labels. 997 if (MAI->hasSetDirective()) { 998 // If we used .set, reference the .set's symbol. 999 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1000 OutContext); 1001 break; 1002 } 1003 // Otherwise, use the difference as the jump table entry. 1004 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1005 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1006 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1007 break; 1008 } 1009 } 1010 1011 assert(Value && "Unknown entry kind!"); 1012 1013 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1014 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1015} 1016 1017 1018/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1019/// special global used by LLVM. If so, emit it and return true, otherwise 1020/// do nothing and return false. 1021bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1022 if (GV->getName() == "llvm.used") { 1023 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1024 EmitLLVMUsedList(GV->getInitializer()); 1025 return true; 1026 } 1027 1028 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1029 if (GV->getSection() == "llvm.metadata" || 1030 GV->hasAvailableExternallyLinkage()) 1031 return true; 1032 1033 if (!GV->hasAppendingLinkage()) return false; 1034 1035 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1036 1037 const TargetData *TD = TM.getTargetData(); 1038 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1039 if (GV->getName() == "llvm.global_ctors") { 1040 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1041 EmitAlignment(Align); 1042 EmitXXStructorList(GV->getInitializer()); 1043 1044 if (TM.getRelocationModel() == Reloc::Static && 1045 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1046 StringRef Sym(".constructors_used"); 1047 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1048 MCSA_Reference); 1049 } 1050 return true; 1051 } 1052 1053 if (GV->getName() == "llvm.global_dtors") { 1054 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1055 EmitAlignment(Align); 1056 EmitXXStructorList(GV->getInitializer()); 1057 1058 if (TM.getRelocationModel() == Reloc::Static && 1059 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1060 StringRef Sym(".destructors_used"); 1061 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1062 MCSA_Reference); 1063 } 1064 return true; 1065 } 1066 1067 return false; 1068} 1069 1070/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1071/// global in the specified llvm.used list for which emitUsedDirectiveFor 1072/// is true, as being used with this directive. 1073void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1074 // Should be an array of 'i8*'. 1075 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1076 if (InitList == 0) return; 1077 1078 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1079 const GlobalValue *GV = 1080 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1081 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1082 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1083 } 1084} 1085 1086/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1087/// function pointers, ignoring the init priority. 1088void AsmPrinter::EmitXXStructorList(Constant *List) { 1089 // Should be an array of '{ int, void ()* }' structs. The first value is the 1090 // init priority, which we ignore. 1091 if (!isa<ConstantArray>(List)) return; 1092 ConstantArray *InitList = cast<ConstantArray>(List); 1093 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1094 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1095 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1096 1097 if (CS->getOperand(1)->isNullValue()) 1098 return; // Found a null terminator, exit printing. 1099 // Emit the function pointer. 1100 EmitGlobalConstant(CS->getOperand(1)); 1101 } 1102} 1103 1104//===--------------------------------------------------------------------===// 1105// Emission and print routines 1106// 1107 1108/// EmitInt8 - Emit a byte directive and value. 1109/// 1110void AsmPrinter::EmitInt8(int Value) const { 1111 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1112} 1113 1114/// EmitInt16 - Emit a short directive and value. 1115/// 1116void AsmPrinter::EmitInt16(int Value) const { 1117 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1118} 1119 1120/// EmitInt32 - Emit a long directive and value. 1121/// 1122void AsmPrinter::EmitInt32(int Value) const { 1123 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1124} 1125 1126/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1127/// in bytes of the directive is specified by Size and Hi/Lo specify the 1128/// labels. This implicitly uses .set if it is available. 1129void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1130 unsigned Size) const { 1131 // Get the Hi-Lo expression. 1132 const MCExpr *Diff = 1133 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1134 MCSymbolRefExpr::Create(Lo, OutContext), 1135 OutContext); 1136 1137 if (!MAI->hasSetDirective()) { 1138 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1139 return; 1140 } 1141 1142 // Otherwise, emit with .set (aka assignment). 1143 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1144 OutStreamer.EmitAssignment(SetLabel, Diff); 1145 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1146} 1147 1148/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1149/// where the size in bytes of the directive is specified by Size and Hi/Lo 1150/// specify the labels. This implicitly uses .set if it is available. 1151void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1152 const MCSymbol *Lo, unsigned Size) 1153 const { 1154 1155 // Emit Hi+Offset - Lo 1156 // Get the Hi+Offset expression. 1157 const MCExpr *Plus = 1158 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1159 MCConstantExpr::Create(Offset, OutContext), 1160 OutContext); 1161 1162 // Get the Hi+Offset-Lo expression. 1163 const MCExpr *Diff = 1164 MCBinaryExpr::CreateSub(Plus, 1165 MCSymbolRefExpr::Create(Lo, OutContext), 1166 OutContext); 1167 1168 if (!MAI->hasSetDirective()) 1169 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1170 else { 1171 // Otherwise, emit with .set (aka assignment). 1172 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1173 OutStreamer.EmitAssignment(SetLabel, Diff); 1174 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1175 } 1176} 1177 1178 1179//===----------------------------------------------------------------------===// 1180 1181// EmitAlignment - Emit an alignment directive to the specified power of 1182// two boundary. For example, if you pass in 3 here, you will get an 8 1183// byte alignment. If a global value is specified, and if that global has 1184// an explicit alignment requested, it will override the alignment request 1185// if required for correctness. 1186// 1187void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1188 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1189 1190 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1191 1192 if (getCurrentSection()->getKind().isText()) 1193 OutStreamer.EmitCodeAlignment(1 << NumBits); 1194 else 1195 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1196} 1197 1198//===----------------------------------------------------------------------===// 1199// Constant emission. 1200//===----------------------------------------------------------------------===// 1201 1202/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1203/// 1204static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1205 MCContext &Ctx = AP.OutContext; 1206 1207 if (CV->isNullValue() || isa<UndefValue>(CV)) 1208 return MCConstantExpr::Create(0, Ctx); 1209 1210 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1211 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1212 1213 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1214 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1215 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1216 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1217 1218 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1219 if (CE == 0) { 1220 llvm_unreachable("Unknown constant value to lower!"); 1221 return MCConstantExpr::Create(0, Ctx); 1222 } 1223 1224 switch (CE->getOpcode()) { 1225 default: 1226 // If the code isn't optimized, there may be outstanding folding 1227 // opportunities. Attempt to fold the expression using TargetData as a 1228 // last resort before giving up. 1229 if (Constant *C = 1230 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1231 if (C != CE) 1232 return LowerConstant(C, AP); 1233#ifndef NDEBUG 1234 CE->dump(); 1235#endif 1236 llvm_unreachable("FIXME: Don't support this constant expr"); 1237 case Instruction::GetElementPtr: { 1238 const TargetData &TD = *AP.TM.getTargetData(); 1239 // Generate a symbolic expression for the byte address 1240 const Constant *PtrVal = CE->getOperand(0); 1241 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1242 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1243 IdxVec.size()); 1244 1245 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1246 if (Offset == 0) 1247 return Base; 1248 1249 // Truncate/sext the offset to the pointer size. 1250 if (TD.getPointerSizeInBits() != 64) { 1251 int SExtAmount = 64-TD.getPointerSizeInBits(); 1252 Offset = (Offset << SExtAmount) >> SExtAmount; 1253 } 1254 1255 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1256 Ctx); 1257 } 1258 1259 case Instruction::Trunc: 1260 // We emit the value and depend on the assembler to truncate the generated 1261 // expression properly. This is important for differences between 1262 // blockaddress labels. Since the two labels are in the same function, it 1263 // is reasonable to treat their delta as a 32-bit value. 1264 // FALL THROUGH. 1265 case Instruction::BitCast: 1266 return LowerConstant(CE->getOperand(0), AP); 1267 1268 case Instruction::IntToPtr: { 1269 const TargetData &TD = *AP.TM.getTargetData(); 1270 // Handle casts to pointers by changing them into casts to the appropriate 1271 // integer type. This promotes constant folding and simplifies this code. 1272 Constant *Op = CE->getOperand(0); 1273 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1274 false/*ZExt*/); 1275 return LowerConstant(Op, AP); 1276 } 1277 1278 case Instruction::PtrToInt: { 1279 const TargetData &TD = *AP.TM.getTargetData(); 1280 // Support only foldable casts to/from pointers that can be eliminated by 1281 // changing the pointer to the appropriately sized integer type. 1282 Constant *Op = CE->getOperand(0); 1283 const Type *Ty = CE->getType(); 1284 1285 const MCExpr *OpExpr = LowerConstant(Op, AP); 1286 1287 // We can emit the pointer value into this slot if the slot is an 1288 // integer slot equal to the size of the pointer. 1289 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1290 return OpExpr; 1291 1292 // Otherwise the pointer is smaller than the resultant integer, mask off 1293 // the high bits so we are sure to get a proper truncation if the input is 1294 // a constant expr. 1295 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1296 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1297 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1298 } 1299 1300 // The MC library also has a right-shift operator, but it isn't consistently 1301 // signed or unsigned between different targets. 1302 case Instruction::Add: 1303 case Instruction::Sub: 1304 case Instruction::Mul: 1305 case Instruction::SDiv: 1306 case Instruction::SRem: 1307 case Instruction::Shl: 1308 case Instruction::And: 1309 case Instruction::Or: 1310 case Instruction::Xor: { 1311 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1312 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1313 switch (CE->getOpcode()) { 1314 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1315 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1316 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1317 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1318 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1319 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1320 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1321 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1322 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1323 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1324 } 1325 } 1326 } 1327} 1328 1329static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1330 AsmPrinter &AP); 1331 1332static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1333 AsmPrinter &AP) { 1334 if (AddrSpace != 0 || !CA->isString()) { 1335 // Not a string. Print the values in successive locations 1336 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1337 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1338 return; 1339 } 1340 1341 // Otherwise, it can be emitted as .ascii. 1342 SmallVector<char, 128> TmpVec; 1343 TmpVec.reserve(CA->getNumOperands()); 1344 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1345 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1346 1347 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1348} 1349 1350static void EmitGlobalConstantVector(const ConstantVector *CV, 1351 unsigned AddrSpace, AsmPrinter &AP) { 1352 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1353 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1354} 1355 1356static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1357 unsigned AddrSpace, AsmPrinter &AP) { 1358 // Print the fields in successive locations. Pad to align if needed! 1359 const TargetData *TD = AP.TM.getTargetData(); 1360 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1361 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1362 uint64_t SizeSoFar = 0; 1363 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1364 const Constant *Field = CS->getOperand(i); 1365 1366 // Check if padding is needed and insert one or more 0s. 1367 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1368 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1369 - Layout->getElementOffset(i)) - FieldSize; 1370 SizeSoFar += FieldSize + PadSize; 1371 1372 // Now print the actual field value. 1373 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1374 1375 // Insert padding - this may include padding to increase the size of the 1376 // current field up to the ABI size (if the struct is not packed) as well 1377 // as padding to ensure that the next field starts at the right offset. 1378 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1379 } 1380 assert(SizeSoFar == Layout->getSizeInBytes() && 1381 "Layout of constant struct may be incorrect!"); 1382} 1383 1384static void EmitGlobalConstantUnion(const ConstantUnion *CU, 1385 unsigned AddrSpace, AsmPrinter &AP) { 1386 const TargetData *TD = AP.TM.getTargetData(); 1387 unsigned Size = TD->getTypeAllocSize(CU->getType()); 1388 1389 const Constant *Contents = CU->getOperand(0); 1390 unsigned FilledSize = TD->getTypeAllocSize(Contents->getType()); 1391 1392 // Print the actually filled part 1393 EmitGlobalConstantImpl(Contents, AddrSpace, AP); 1394 1395 // And pad with enough zeroes 1396 AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace); 1397} 1398 1399static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1400 AsmPrinter &AP) { 1401 // FP Constants are printed as integer constants to avoid losing 1402 // precision. 1403 if (CFP->getType()->isDoubleTy()) { 1404 if (AP.isVerbose()) { 1405 double Val = CFP->getValueAPF().convertToDouble(); 1406 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1407 } 1408 1409 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1410 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1411 return; 1412 } 1413 1414 if (CFP->getType()->isFloatTy()) { 1415 if (AP.isVerbose()) { 1416 float Val = CFP->getValueAPF().convertToFloat(); 1417 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1418 } 1419 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1420 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1421 return; 1422 } 1423 1424 if (CFP->getType()->isX86_FP80Ty()) { 1425 // all long double variants are printed as hex 1426 // API needed to prevent premature destruction 1427 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1428 const uint64_t *p = API.getRawData(); 1429 if (AP.isVerbose()) { 1430 // Convert to double so we can print the approximate val as a comment. 1431 APFloat DoubleVal = CFP->getValueAPF(); 1432 bool ignored; 1433 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1434 &ignored); 1435 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1436 << DoubleVal.convertToDouble() << '\n'; 1437 } 1438 1439 if (AP.TM.getTargetData()->isBigEndian()) { 1440 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1441 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1442 } else { 1443 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1444 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1445 } 1446 1447 // Emit the tail padding for the long double. 1448 const TargetData &TD = *AP.TM.getTargetData(); 1449 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1450 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1451 return; 1452 } 1453 1454 assert(CFP->getType()->isPPC_FP128Ty() && 1455 "Floating point constant type not handled"); 1456 // All long double variants are printed as hex 1457 // API needed to prevent premature destruction. 1458 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1459 const uint64_t *p = API.getRawData(); 1460 if (AP.TM.getTargetData()->isBigEndian()) { 1461 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1462 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1463 } else { 1464 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1465 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1466 } 1467} 1468 1469static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1470 unsigned AddrSpace, AsmPrinter &AP) { 1471 const TargetData *TD = AP.TM.getTargetData(); 1472 unsigned BitWidth = CI->getBitWidth(); 1473 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1474 1475 // We don't expect assemblers to support integer data directives 1476 // for more than 64 bits, so we emit the data in at most 64-bit 1477 // quantities at a time. 1478 const uint64_t *RawData = CI->getValue().getRawData(); 1479 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1480 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1481 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1482 } 1483} 1484 1485static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1486 AsmPrinter &AP) { 1487 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1488 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1489 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1490 } 1491 1492 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1493 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1494 switch (Size) { 1495 case 1: 1496 case 2: 1497 case 4: 1498 case 8: 1499 if (AP.isVerbose()) 1500 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1501 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1502 return; 1503 default: 1504 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1505 return; 1506 } 1507 } 1508 1509 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1510 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1511 1512 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1513 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1514 1515 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1516 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1517 1518 if (isa<ConstantPointerNull>(CV)) { 1519 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1520 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1521 return; 1522 } 1523 1524 if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV)) 1525 return EmitGlobalConstantUnion(CVU, AddrSpace, AP); 1526 1527 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1528 return EmitGlobalConstantVector(V, AddrSpace, AP); 1529 1530 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1531 // thread the streamer with EmitValue. 1532 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1533 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1534 AddrSpace); 1535} 1536 1537/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1538void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1539 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1540 if (Size) 1541 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1542 else if (MAI->hasSubsectionsViaSymbols()) { 1543 // If the global has zero size, emit a single byte so that two labels don't 1544 // look like they are at the same location. 1545 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1546 } 1547} 1548 1549void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1550 // Target doesn't support this yet! 1551 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1552} 1553 1554void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1555 if (Offset > 0) 1556 OS << '+' << Offset; 1557 else if (Offset < 0) 1558 OS << Offset; 1559} 1560 1561//===----------------------------------------------------------------------===// 1562// Symbol Lowering Routines. 1563//===----------------------------------------------------------------------===// 1564 1565/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1566/// temporary label with the specified stem and unique ID. 1567MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1568 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1569 Name + Twine(ID)); 1570} 1571 1572/// GetTempSymbol - Return an assembler temporary label with the specified 1573/// stem. 1574MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1575 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1576 Name); 1577} 1578 1579 1580MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1581 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1582} 1583 1584MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1585 return MMI->getAddrLabelSymbol(BB); 1586} 1587 1588/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1589MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1590 return OutContext.GetOrCreateSymbol 1591 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1592 + "_" + Twine(CPID)); 1593} 1594 1595/// GetJTISymbol - Return the symbol for the specified jump table entry. 1596MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1597 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1598} 1599 1600/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1601/// FIXME: privatize to AsmPrinter. 1602MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1603 return OutContext.GetOrCreateSymbol 1604 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1605 Twine(UID) + "_set_" + Twine(MBBID)); 1606} 1607 1608/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1609/// global value name as its base, with the specified suffix, and where the 1610/// symbol is forced to have private linkage if ForcePrivate is true. 1611MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1612 StringRef Suffix, 1613 bool ForcePrivate) const { 1614 SmallString<60> NameStr; 1615 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1616 NameStr.append(Suffix.begin(), Suffix.end()); 1617 return OutContext.GetOrCreateSymbol(NameStr.str()); 1618} 1619 1620/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1621/// ExternalSymbol. 1622MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1623 SmallString<60> NameStr; 1624 Mang->getNameWithPrefix(NameStr, Sym); 1625 return OutContext.GetOrCreateSymbol(NameStr.str()); 1626} 1627 1628 1629 1630/// PrintParentLoopComment - Print comments about parent loops of this one. 1631static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1632 unsigned FunctionNumber) { 1633 if (Loop == 0) return; 1634 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1635 OS.indent(Loop->getLoopDepth()*2) 1636 << "Parent Loop BB" << FunctionNumber << "_" 1637 << Loop->getHeader()->getNumber() 1638 << " Depth=" << Loop->getLoopDepth() << '\n'; 1639} 1640 1641 1642/// PrintChildLoopComment - Print comments about child loops within 1643/// the loop for this basic block, with nesting. 1644static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1645 unsigned FunctionNumber) { 1646 // Add child loop information 1647 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1648 OS.indent((*CL)->getLoopDepth()*2) 1649 << "Child Loop BB" << FunctionNumber << "_" 1650 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1651 << '\n'; 1652 PrintChildLoopComment(OS, *CL, FunctionNumber); 1653 } 1654} 1655 1656/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1657static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1658 const MachineLoopInfo *LI, 1659 const AsmPrinter &AP) { 1660 // Add loop depth information 1661 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1662 if (Loop == 0) return; 1663 1664 MachineBasicBlock *Header = Loop->getHeader(); 1665 assert(Header && "No header for loop"); 1666 1667 // If this block is not a loop header, just print out what is the loop header 1668 // and return. 1669 if (Header != &MBB) { 1670 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1671 Twine(AP.getFunctionNumber())+"_" + 1672 Twine(Loop->getHeader()->getNumber())+ 1673 " Depth="+Twine(Loop->getLoopDepth())); 1674 return; 1675 } 1676 1677 // Otherwise, it is a loop header. Print out information about child and 1678 // parent loops. 1679 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1680 1681 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1682 1683 OS << "=>"; 1684 OS.indent(Loop->getLoopDepth()*2-2); 1685 1686 OS << "This "; 1687 if (Loop->empty()) 1688 OS << "Inner "; 1689 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1690 1691 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1692} 1693 1694 1695/// EmitBasicBlockStart - This method prints the label for the specified 1696/// MachineBasicBlock, an alignment (if present) and a comment describing 1697/// it if appropriate. 1698void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1699 // Emit an alignment directive for this block, if needed. 1700 if (unsigned Align = MBB->getAlignment()) 1701 EmitAlignment(Log2_32(Align)); 1702 1703 // If the block has its address taken, emit any labels that were used to 1704 // reference the block. It is possible that there is more than one label 1705 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1706 // the references were generated. 1707 if (MBB->hasAddressTaken()) { 1708 const BasicBlock *BB = MBB->getBasicBlock(); 1709 if (isVerbose()) 1710 OutStreamer.AddComment("Block address taken"); 1711 1712 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1713 1714 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1715 OutStreamer.EmitLabel(Syms[i]); 1716 } 1717 1718 // Print the main label for the block. 1719 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1720 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1721 if (const BasicBlock *BB = MBB->getBasicBlock()) 1722 if (BB->hasName()) 1723 OutStreamer.AddComment("%" + BB->getName()); 1724 1725 EmitBasicBlockLoopComments(*MBB, LI, *this); 1726 1727 // NOTE: Want this comment at start of line, don't emit with AddComment. 1728 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1729 Twine(MBB->getNumber()) + ":"); 1730 } 1731 } else { 1732 if (isVerbose()) { 1733 if (const BasicBlock *BB = MBB->getBasicBlock()) 1734 if (BB->hasName()) 1735 OutStreamer.AddComment("%" + BB->getName()); 1736 EmitBasicBlockLoopComments(*MBB, LI, *this); 1737 } 1738 1739 OutStreamer.EmitLabel(MBB->getSymbol()); 1740 } 1741} 1742 1743void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1744 MCSymbolAttr Attr = MCSA_Invalid; 1745 1746 switch (Visibility) { 1747 default: break; 1748 case GlobalValue::HiddenVisibility: 1749 Attr = MAI->getHiddenVisibilityAttr(); 1750 break; 1751 case GlobalValue::ProtectedVisibility: 1752 Attr = MAI->getProtectedVisibilityAttr(); 1753 break; 1754 } 1755 1756 if (Attr != MCSA_Invalid) 1757 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1758} 1759 1760/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1761/// exactly one predecessor and the control transfer mechanism between 1762/// the predecessor and this block is a fall-through. 1763bool AsmPrinter:: 1764isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1765 // If this is a landing pad, it isn't a fall through. If it has no preds, 1766 // then nothing falls through to it. 1767 if (MBB->isLandingPad() || MBB->pred_empty()) 1768 return false; 1769 1770 // If there isn't exactly one predecessor, it can't be a fall through. 1771 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1772 ++PI2; 1773 if (PI2 != MBB->pred_end()) 1774 return false; 1775 1776 // The predecessor has to be immediately before this block. 1777 const MachineBasicBlock *Pred = *PI; 1778 1779 if (!Pred->isLayoutSuccessor(MBB)) 1780 return false; 1781 1782 // If the block is completely empty, then it definitely does fall through. 1783 if (Pred->empty()) 1784 return true; 1785 1786 // Otherwise, check the last instruction. 1787 const MachineInstr &LastInst = Pred->back(); 1788 return !LastInst.getDesc().isBarrier(); 1789} 1790 1791 1792 1793GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1794 if (!S->usesMetadata()) 1795 return 0; 1796 1797 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1798 gcp_map_type::iterator GCPI = GCMap.find(S); 1799 if (GCPI != GCMap.end()) 1800 return GCPI->second; 1801 1802 const char *Name = S->getName().c_str(); 1803 1804 for (GCMetadataPrinterRegistry::iterator 1805 I = GCMetadataPrinterRegistry::begin(), 1806 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1807 if (strcmp(Name, I->getName()) == 0) { 1808 GCMetadataPrinter *GMP = I->instantiate(); 1809 GMP->S = S; 1810 GCMap.insert(std::make_pair(S, GMP)); 1811 return GMP; 1812 } 1813 1814 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1815 return 0; 1816} 1817 1818