AsmPrinter.cpp revision f0adba9a7ec8a3031876575a6ffb7db5f1b6f855
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the AsmPrinter class. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "asm-printer" 15#include "llvm/CodeGen/AsmPrinter.h" 16#include "DwarfDebug.h" 17#include "DwarfException.h" 18#include "llvm/Module.h" 19#include "llvm/CodeGen/GCMetadataPrinter.h" 20#include "llvm/CodeGen/MachineConstantPool.h" 21#include "llvm/CodeGen/MachineFrameInfo.h" 22#include "llvm/CodeGen/MachineFunction.h" 23#include "llvm/CodeGen/MachineJumpTableInfo.h" 24#include "llvm/CodeGen/MachineLoopInfo.h" 25#include "llvm/CodeGen/MachineModuleInfo.h" 26#include "llvm/Analysis/ConstantFolding.h" 27#include "llvm/Analysis/DebugInfo.h" 28#include "llvm/MC/MCAsmInfo.h" 29#include "llvm/MC/MCContext.h" 30#include "llvm/MC/MCExpr.h" 31#include "llvm/MC/MCInst.h" 32#include "llvm/MC/MCSection.h" 33#include "llvm/MC/MCStreamer.h" 34#include "llvm/MC/MCSymbol.h" 35#include "llvm/Target/Mangler.h" 36#include "llvm/Target/TargetAsmInfo.h" 37#include "llvm/Target/TargetData.h" 38#include "llvm/Target/TargetInstrInfo.h" 39#include "llvm/Target/TargetLowering.h" 40#include "llvm/Target/TargetLoweringObjectFile.h" 41#include "llvm/Target/TargetRegisterInfo.h" 42#include "llvm/Assembly/Writer.h" 43#include "llvm/ADT/SmallString.h" 44#include "llvm/ADT/Statistic.h" 45#include "llvm/Support/ErrorHandling.h" 46#include "llvm/Support/Format.h" 47#include "llvm/Support/Timer.h" 48using namespace llvm; 49 50static const char *DWARFGroupName = "DWARF Emission"; 51static const char *DbgTimerName = "DWARF Debug Writer"; 52static const char *EHTimerName = "DWARF Exception Writer"; 53 54STATISTIC(EmittedInsts, "Number of machine instrs printed"); 55 56char AsmPrinter::ID = 0; 57 58typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 59static gcp_map_type &getGCMap(void *&P) { 60 if (P == 0) 61 P = new gcp_map_type(); 62 return *(gcp_map_type*)P; 63} 64 65 66/// getGVAlignmentLog2 - Return the alignment to use for the specified global 67/// value in log2 form. This rounds up to the preferred alignment if possible 68/// and legal. 69static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 70 unsigned InBits = 0) { 71 unsigned NumBits = 0; 72 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 73 NumBits = TD.getPreferredAlignmentLog(GVar); 74 75 // If InBits is specified, round it to it. 76 if (InBits > NumBits) 77 NumBits = InBits; 78 79 // If the GV has a specified alignment, take it into account. 80 if (GV->getAlignment() == 0) 81 return NumBits; 82 83 unsigned GVAlign = Log2_32(GV->getAlignment()); 84 85 // If the GVAlign is larger than NumBits, or if we are required to obey 86 // NumBits because the GV has an assigned section, obey it. 87 if (GVAlign > NumBits || GV->hasSection()) 88 NumBits = GVAlign; 89 return NumBits; 90} 91 92 93 94 95AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 96 : MachineFunctionPass(ID), 97 TM(tm), MAI(tm.getMCAsmInfo()), 98 OutContext(Streamer.getContext()), 99 OutStreamer(Streamer), 100 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 101 DD = 0; DE = 0; MMI = 0; LI = 0; 102 GCMetadataPrinters = 0; 103 VerboseAsm = Streamer.isVerboseAsm(); 104} 105 106AsmPrinter::~AsmPrinter() { 107 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 108 109 if (GCMetadataPrinters != 0) { 110 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 111 112 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 113 delete I->second; 114 delete &GCMap; 115 GCMetadataPrinters = 0; 116 } 117 118 delete &OutStreamer; 119} 120 121/// getFunctionNumber - Return a unique ID for the current function. 122/// 123unsigned AsmPrinter::getFunctionNumber() const { 124 return MF->getFunctionNumber(); 125} 126 127const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 128 return TM.getTargetLowering()->getObjFileLowering(); 129} 130 131 132/// getTargetData - Return information about data layout. 133const TargetData &AsmPrinter::getTargetData() const { 134 return *TM.getTargetData(); 135} 136 137/// getCurrentSection() - Return the current section we are emitting to. 138const MCSection *AsmPrinter::getCurrentSection() const { 139 return OutStreamer.getCurrentSection(); 140} 141 142 143 144void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 145 AU.setPreservesAll(); 146 MachineFunctionPass::getAnalysisUsage(AU); 147 AU.addRequired<MachineModuleInfo>(); 148 AU.addRequired<GCModuleInfo>(); 149 if (isVerbose()) 150 AU.addRequired<MachineLoopInfo>(); 151} 152 153bool AsmPrinter::doInitialization(Module &M) { 154 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 155 MMI->AnalyzeModule(M); 156 157 // Initialize TargetLoweringObjectFile. 158 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 159 .Initialize(OutContext, TM); 160 161 Mang = new Mangler(OutContext, *TM.getTargetData()); 162 163 // Allow the target to emit any magic that it wants at the start of the file. 164 EmitStartOfAsmFile(M); 165 166 // Very minimal debug info. It is ignored if we emit actual debug info. If we 167 // don't, this at least helps the user find where a global came from. 168 if (MAI->hasSingleParameterDotFile()) { 169 // .file "foo.c" 170 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 171 } 172 173 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 174 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 175 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 176 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 177 MP->beginAssembly(*this); 178 179 // Emit module-level inline asm if it exists. 180 if (!M.getModuleInlineAsm().empty()) { 181 OutStreamer.AddComment("Start of file scope inline assembly"); 182 OutStreamer.AddBlankLine(); 183 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 184 OutStreamer.AddComment("End of file scope inline assembly"); 185 OutStreamer.AddBlankLine(); 186 } 187 188 if (MAI->doesSupportDebugInformation()) 189 DD = new DwarfDebug(this, &M); 190 191 if (MAI->doesSupportExceptionHandling()) 192 switch (MAI->getExceptionHandlingType()) { 193 default: 194 case ExceptionHandling::DwarfTable: 195 DE = new DwarfTableException(this); 196 break; 197 case ExceptionHandling::DwarfCFI: 198 DE = new DwarfCFIException(this); 199 break; 200 case ExceptionHandling::ARM: 201 DE = new ARMException(this); 202 break; 203 } 204 205 return false; 206} 207 208void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 209 switch ((GlobalValue::LinkageTypes)Linkage) { 210 case GlobalValue::CommonLinkage: 211 case GlobalValue::LinkOnceAnyLinkage: 212 case GlobalValue::LinkOnceODRLinkage: 213 case GlobalValue::WeakAnyLinkage: 214 case GlobalValue::WeakODRLinkage: 215 case GlobalValue::LinkerPrivateWeakLinkage: 216 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 217 if (MAI->getWeakDefDirective() != 0) { 218 // .globl _foo 219 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 220 221 if ((GlobalValue::LinkageTypes)Linkage != 222 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 223 // .weak_definition _foo 224 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 225 else 226 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 227 } else if (MAI->getLinkOnceDirective() != 0) { 228 // .globl _foo 229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 230 //NOTE: linkonce is handled by the section the symbol was assigned to. 231 } else { 232 // .weak _foo 233 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 234 } 235 break; 236 case GlobalValue::DLLExportLinkage: 237 case GlobalValue::AppendingLinkage: 238 // FIXME: appending linkage variables should go into a section of 239 // their name or something. For now, just emit them as external. 240 case GlobalValue::ExternalLinkage: 241 // If external or appending, declare as a global symbol. 242 // .globl _foo 243 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 244 break; 245 case GlobalValue::PrivateLinkage: 246 case GlobalValue::InternalLinkage: 247 case GlobalValue::LinkerPrivateLinkage: 248 break; 249 default: 250 llvm_unreachable("Unknown linkage type!"); 251 } 252} 253 254 255/// EmitGlobalVariable - Emit the specified global variable to the .s file. 256void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 257 if (GV->hasInitializer()) { 258 // Check to see if this is a special global used by LLVM, if so, emit it. 259 if (EmitSpecialLLVMGlobal(GV)) 260 return; 261 262 if (isVerbose()) { 263 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 264 /*PrintType=*/false, GV->getParent()); 265 OutStreamer.GetCommentOS() << '\n'; 266 } 267 } 268 269 MCSymbol *GVSym = Mang->getSymbol(GV); 270 EmitVisibility(GVSym, GV->getVisibility()); 271 272 if (!GV->hasInitializer()) // External globals require no extra code. 273 return; 274 275 if (MAI->hasDotTypeDotSizeDirective()) 276 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 277 278 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 279 280 const TargetData *TD = TM.getTargetData(); 281 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 282 283 // If the alignment is specified, we *must* obey it. Overaligning a global 284 // with a specified alignment is a prompt way to break globals emitted to 285 // sections and expected to be contiguous (e.g. ObjC metadata). 286 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 287 288 // Handle common and BSS local symbols (.lcomm). 289 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 290 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 291 292 if (isVerbose()) { 293 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 294 /*PrintType=*/false, GV->getParent()); 295 OutStreamer.GetCommentOS() << '\n'; 296 } 297 298 // Handle common symbols. 299 if (GVKind.isCommon()) { 300 unsigned Align = 1 << AlignLog; 301 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 302 Align = 0; 303 304 // .comm _foo, 42, 4 305 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 306 return; 307 } 308 309 // Handle local BSS symbols. 310 if (MAI->hasMachoZeroFillDirective()) { 311 const MCSection *TheSection = 312 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 313 // .zerofill __DATA, __bss, _foo, 400, 5 314 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 315 return; 316 } 317 318 if (MAI->hasLCOMMDirective()) { 319 // .lcomm _foo, 42 320 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 321 return; 322 } 323 324 unsigned Align = 1 << AlignLog; 325 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 326 Align = 0; 327 328 // .local _foo 329 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 330 // .comm _foo, 42, 4 331 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 332 return; 333 } 334 335 const MCSection *TheSection = 336 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 337 338 // Handle the zerofill directive on darwin, which is a special form of BSS 339 // emission. 340 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 341 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 342 343 // .globl _foo 344 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 345 // .zerofill __DATA, __common, _foo, 400, 5 346 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 347 return; 348 } 349 350 // Handle thread local data for mach-o which requires us to output an 351 // additional structure of data and mangle the original symbol so that we 352 // can reference it later. 353 // 354 // TODO: This should become an "emit thread local global" method on TLOF. 355 // All of this macho specific stuff should be sunk down into TLOFMachO and 356 // stuff like "TLSExtraDataSection" should no longer be part of the parent 357 // TLOF class. This will also make it more obvious that stuff like 358 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 359 // specific code. 360 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 361 // Emit the .tbss symbol 362 MCSymbol *MangSym = 363 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 364 365 if (GVKind.isThreadBSS()) 366 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 367 else if (GVKind.isThreadData()) { 368 OutStreamer.SwitchSection(TheSection); 369 370 EmitAlignment(AlignLog, GV); 371 OutStreamer.EmitLabel(MangSym); 372 373 EmitGlobalConstant(GV->getInitializer()); 374 } 375 376 OutStreamer.AddBlankLine(); 377 378 // Emit the variable struct for the runtime. 379 const MCSection *TLVSect 380 = getObjFileLowering().getTLSExtraDataSection(); 381 382 OutStreamer.SwitchSection(TLVSect); 383 // Emit the linkage here. 384 EmitLinkage(GV->getLinkage(), GVSym); 385 OutStreamer.EmitLabel(GVSym); 386 387 // Three pointers in size: 388 // - __tlv_bootstrap - used to make sure support exists 389 // - spare pointer, used when mapped by the runtime 390 // - pointer to mangled symbol above with initializer 391 unsigned PtrSize = TD->getPointerSizeInBits()/8; 392 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 393 PtrSize, 0); 394 OutStreamer.EmitIntValue(0, PtrSize, 0); 395 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 396 397 OutStreamer.AddBlankLine(); 398 return; 399 } 400 401 OutStreamer.SwitchSection(TheSection); 402 403 EmitLinkage(GV->getLinkage(), GVSym); 404 EmitAlignment(AlignLog, GV); 405 406 OutStreamer.EmitLabel(GVSym); 407 408 EmitGlobalConstant(GV->getInitializer()); 409 410 if (MAI->hasDotTypeDotSizeDirective()) 411 // .size foo, 42 412 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 413 414 OutStreamer.AddBlankLine(); 415} 416 417/// EmitFunctionHeader - This method emits the header for the current 418/// function. 419void AsmPrinter::EmitFunctionHeader() { 420 // Print out constants referenced by the function 421 EmitConstantPool(); 422 423 // Print the 'header' of function. 424 const Function *F = MF->getFunction(); 425 426 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 427 EmitVisibility(CurrentFnSym, F->getVisibility()); 428 429 EmitLinkage(F->getLinkage(), CurrentFnSym); 430 EmitAlignment(MF->getAlignment(), F); 431 432 if (MAI->hasDotTypeDotSizeDirective()) 433 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 434 435 if (isVerbose()) { 436 WriteAsOperand(OutStreamer.GetCommentOS(), F, 437 /*PrintType=*/false, F->getParent()); 438 OutStreamer.GetCommentOS() << '\n'; 439 } 440 441 // Emit the CurrentFnSym. This is a virtual function to allow targets to 442 // do their wild and crazy things as required. 443 EmitFunctionEntryLabel(); 444 445 // If the function had address-taken blocks that got deleted, then we have 446 // references to the dangling symbols. Emit them at the start of the function 447 // so that we don't get references to undefined symbols. 448 std::vector<MCSymbol*> DeadBlockSyms; 449 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 450 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 451 OutStreamer.AddComment("Address taken block that was later removed"); 452 OutStreamer.EmitLabel(DeadBlockSyms[i]); 453 } 454 455 // Add some workaround for linkonce linkage on Cygwin\MinGW. 456 if (MAI->getLinkOnceDirective() != 0 && 457 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 458 // FIXME: What is this? 459 MCSymbol *FakeStub = 460 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 461 CurrentFnSym->getName()); 462 OutStreamer.EmitLabel(FakeStub); 463 } 464 465 // Emit pre-function debug and/or EH information. 466 if (DE) { 467 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 468 DE->BeginFunction(MF); 469 } 470 if (DD) { 471 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 472 DD->beginFunction(MF); 473 } 474} 475 476/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 477/// function. This can be overridden by targets as required to do custom stuff. 478void AsmPrinter::EmitFunctionEntryLabel() { 479 // The function label could have already been emitted if two symbols end up 480 // conflicting due to asm renaming. Detect this and emit an error. 481 if (CurrentFnSym->isUndefined()) 482 return OutStreamer.EmitLabel(CurrentFnSym); 483 484 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 485 "' label emitted multiple times to assembly file"); 486} 487 488 489static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF, 490 raw_ostream &CommentOS) { 491 const LLVMContext &Ctx = MF->getFunction()->getContext(); 492 if (!DL.isUnknown()) { // Print source line info. 493 DIScope Scope(DL.getScope(Ctx)); 494 // Omit the directory, because it's likely to be long and uninteresting. 495 if (Scope.Verify()) 496 CommentOS << Scope.getFilename(); 497 else 498 CommentOS << "<unknown>"; 499 CommentOS << ':' << DL.getLine(); 500 if (DL.getCol() != 0) 501 CommentOS << ':' << DL.getCol(); 502 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx)); 503 if (!InlinedAtDL.isUnknown()) { 504 CommentOS << "[ "; 505 EmitDebugLoc(InlinedAtDL, MF, CommentOS); 506 CommentOS << " ]"; 507 } 508 } 509} 510 511/// EmitComments - Pretty-print comments for instructions. 512static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 513 const MachineFunction *MF = MI.getParent()->getParent(); 514 const TargetMachine &TM = MF->getTarget(); 515 516 DebugLoc DL = MI.getDebugLoc(); 517 if (!DL.isUnknown()) { // Print source line info. 518 EmitDebugLoc(DL, MF, CommentOS); 519 CommentOS << '\n'; 520 } 521 522 // Check for spills and reloads 523 int FI; 524 525 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 526 527 // We assume a single instruction only has a spill or reload, not 528 // both. 529 const MachineMemOperand *MMO; 530 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 531 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 532 MMO = *MI.memoperands_begin(); 533 CommentOS << MMO->getSize() << "-byte Reload\n"; 534 } 535 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 536 if (FrameInfo->isSpillSlotObjectIndex(FI)) 537 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 538 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 539 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 540 MMO = *MI.memoperands_begin(); 541 CommentOS << MMO->getSize() << "-byte Spill\n"; 542 } 543 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 544 if (FrameInfo->isSpillSlotObjectIndex(FI)) 545 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 546 } 547 548 // Check for spill-induced copies 549 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 550 CommentOS << " Reload Reuse\n"; 551} 552 553/// EmitImplicitDef - This method emits the specified machine instruction 554/// that is an implicit def. 555static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 556 unsigned RegNo = MI->getOperand(0).getReg(); 557 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 558 AP.TM.getRegisterInfo()->getName(RegNo)); 559 AP.OutStreamer.AddBlankLine(); 560} 561 562static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 563 std::string Str = "kill:"; 564 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 565 const MachineOperand &Op = MI->getOperand(i); 566 assert(Op.isReg() && "KILL instruction must have only register operands"); 567 Str += ' '; 568 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 569 Str += (Op.isDef() ? "<def>" : "<kill>"); 570 } 571 AP.OutStreamer.AddComment(Str); 572 AP.OutStreamer.AddBlankLine(); 573} 574 575/// EmitDebugValueComment - This method handles the target-independent form 576/// of DBG_VALUE, returning true if it was able to do so. A false return 577/// means the target will need to handle MI in EmitInstruction. 578static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 579 // This code handles only the 3-operand target-independent form. 580 if (MI->getNumOperands() != 3) 581 return false; 582 583 SmallString<128> Str; 584 raw_svector_ostream OS(Str); 585 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 586 587 // cast away const; DIetc do not take const operands for some reason. 588 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 589 if (V.getContext().isSubprogram()) 590 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 591 OS << V.getName() << " <- "; 592 593 // Register or immediate value. Register 0 means undef. 594 if (MI->getOperand(0).isFPImm()) { 595 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 596 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 597 OS << (double)APF.convertToFloat(); 598 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 599 OS << APF.convertToDouble(); 600 } else { 601 // There is no good way to print long double. Convert a copy to 602 // double. Ah well, it's only a comment. 603 bool ignored; 604 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 605 &ignored); 606 OS << "(long double) " << APF.convertToDouble(); 607 } 608 } else if (MI->getOperand(0).isImm()) { 609 OS << MI->getOperand(0).getImm(); 610 } else { 611 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 612 if (MI->getOperand(0).getReg() == 0) { 613 // Suppress offset, it is not meaningful here. 614 OS << "undef"; 615 // NOTE: Want this comment at start of line, don't emit with AddComment. 616 AP.OutStreamer.EmitRawText(OS.str()); 617 return true; 618 } 619 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 620 } 621 622 OS << '+' << MI->getOperand(1).getImm(); 623 // NOTE: Want this comment at start of line, don't emit with AddComment. 624 AP.OutStreamer.EmitRawText(OS.str()); 625 return true; 626} 627 628void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 629 MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 630 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) { 631 OutStreamer.EmitLabel(Label); 632 return; 633 } 634 635 const MachineFunction &MF = *MI.getParent()->getParent(); 636 MachineModuleInfo &MMI = MF.getMMI(); 637 std::vector<MachineMove> &Moves = MMI.getFrameMoves(); 638 const MachineMove *Move = NULL; 639 for (std::vector<MachineMove>::iterator I = Moves.begin(), 640 E = Moves.end(); I != E; ++I) { 641 if (I->getLabel() == Label) { 642 Move = &*I; 643 break; 644 } 645 } 646 assert(Move); 647 648 const MachineLocation &Dst = Move->getDestination(); 649 const MachineLocation &Src = Move->getSource(); 650 const TargetAsmInfo &AsmInfo = OutContext.getTargetAsmInfo(); 651 if (Dst.isReg() && Dst.getReg() == MachineLocation::VirtualFP) { 652 if (Src.getReg() == MachineLocation::VirtualFP) 653 OutStreamer.EmitCFIDefCfaOffset(-Src.getOffset()); 654 else { 655 unsigned Reg = AsmInfo.getDwarfRegNum(Src.getReg(), true); 656 OutStreamer.EmitCFIDefCfa(Reg, -Src.getOffset()); 657 } 658 } else if (Src.isReg() && Src.getReg() == MachineLocation::VirtualFP) { 659 unsigned Reg = AsmInfo.getDwarfRegNum(Dst.getReg(), true); 660 OutStreamer.EmitCFIDefCfaRegister(Reg); 661 } else { 662 unsigned Reg = AsmInfo.getDwarfRegNum(Src.getReg(), true); 663 OutStreamer.EmitCFIOffset(Reg, -Dst.getOffset()); 664 } 665} 666 667/// EmitFunctionBody - This method emits the body and trailer for a 668/// function. 669void AsmPrinter::EmitFunctionBody() { 670 // Emit target-specific gunk before the function body. 671 EmitFunctionBodyStart(); 672 673 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 674 675 // Print out code for the function. 676 bool HasAnyRealCode = false; 677 const MachineInstr *LastMI = 0; 678 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 679 I != E; ++I) { 680 // Print a label for the basic block. 681 EmitBasicBlockStart(I); 682 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 683 II != IE; ++II) { 684 LastMI = II; 685 686 // Print the assembly for the instruction. 687 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 688 !II->isDebugValue()) { 689 HasAnyRealCode = true; 690 ++EmittedInsts; 691 } 692 693 if (ShouldPrintDebugScopes) { 694 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 695 DD->beginInstruction(II); 696 } 697 698 if (isVerbose()) 699 EmitComments(*II, OutStreamer.GetCommentOS()); 700 701 switch (II->getOpcode()) { 702 case TargetOpcode::PROLOG_LABEL: 703 emitPrologLabel(*II); 704 break; 705 706 case TargetOpcode::EH_LABEL: 707 case TargetOpcode::GC_LABEL: 708 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 709 break; 710 case TargetOpcode::INLINEASM: 711 EmitInlineAsm(II); 712 break; 713 case TargetOpcode::DBG_VALUE: 714 if (isVerbose()) { 715 if (!EmitDebugValueComment(II, *this)) 716 EmitInstruction(II); 717 } 718 break; 719 case TargetOpcode::IMPLICIT_DEF: 720 if (isVerbose()) EmitImplicitDef(II, *this); 721 break; 722 case TargetOpcode::KILL: 723 if (isVerbose()) EmitKill(II, *this); 724 break; 725 default: 726 EmitInstruction(II); 727 break; 728 } 729 730 if (ShouldPrintDebugScopes) { 731 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 732 DD->endInstruction(II); 733 } 734 } 735 } 736 737 // If the last instruction was a prolog label, then we have a situation where 738 // we emitted a prolog but no function body. This results in the ending prolog 739 // label equaling the end of function label and an invalid "row" in the 740 // FDE. We need to emit a noop in this situation so that the FDE's rows are 741 // valid. 742 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 743 744 // If the function is empty and the object file uses .subsections_via_symbols, 745 // then we need to emit *something* to the function body to prevent the 746 // labels from collapsing together. Just emit a noop. 747 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 748 MCInst Noop; 749 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 750 if (Noop.getOpcode()) { 751 OutStreamer.AddComment("avoids zero-length function"); 752 OutStreamer.EmitInstruction(Noop); 753 } else // Target not mc-ized yet. 754 OutStreamer.EmitRawText(StringRef("\tnop\n")); 755 } 756 757 // Emit target-specific gunk after the function body. 758 EmitFunctionBodyEnd(); 759 760 // If the target wants a .size directive for the size of the function, emit 761 // it. 762 if (MAI->hasDotTypeDotSizeDirective()) { 763 // Create a symbol for the end of function, so we can get the size as 764 // difference between the function label and the temp label. 765 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 766 OutStreamer.EmitLabel(FnEndLabel); 767 768 const MCExpr *SizeExp = 769 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 770 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 771 OutContext); 772 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 773 } 774 775 // Emit post-function debug information. 776 if (DD) { 777 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 778 DD->endFunction(MF); 779 } 780 if (DE) { 781 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 782 DE->EndFunction(); 783 } 784 MMI->EndFunction(); 785 786 // Print out jump tables referenced by the function. 787 EmitJumpTableInfo(); 788 789 OutStreamer.AddBlankLine(); 790} 791 792/// getDebugValueLocation - Get location information encoded by DBG_VALUE 793/// operands. 794MachineLocation AsmPrinter:: 795getDebugValueLocation(const MachineInstr *MI) const { 796 // Target specific DBG_VALUE instructions are handled by each target. 797 return MachineLocation(); 798} 799 800bool AsmPrinter::doFinalization(Module &M) { 801 // Emit global variables. 802 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 803 I != E; ++I) 804 EmitGlobalVariable(I); 805 806 // Emit visibility info for declarations 807 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 808 const Function &F = *I; 809 if (!F.isDeclaration()) 810 continue; 811 GlobalValue::VisibilityTypes V = F.getVisibility(); 812 if (V == GlobalValue::DefaultVisibility) 813 continue; 814 815 MCSymbol *Name = Mang->getSymbol(&F); 816 EmitVisibility(Name, V, false); 817 } 818 819 // Finalize debug and EH information. 820 if (DE) { 821 { 822 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 823 DE->EndModule(); 824 } 825 delete DE; DE = 0; 826 } 827 if (DD) { 828 { 829 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 830 DD->endModule(); 831 } 832 delete DD; DD = 0; 833 } 834 835 // If the target wants to know about weak references, print them all. 836 if (MAI->getWeakRefDirective()) { 837 // FIXME: This is not lazy, it would be nice to only print weak references 838 // to stuff that is actually used. Note that doing so would require targets 839 // to notice uses in operands (due to constant exprs etc). This should 840 // happen with the MC stuff eventually. 841 842 // Print out module-level global variables here. 843 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 844 I != E; ++I) { 845 if (!I->hasExternalWeakLinkage()) continue; 846 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 847 } 848 849 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 850 if (!I->hasExternalWeakLinkage()) continue; 851 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 852 } 853 } 854 855 if (MAI->hasSetDirective()) { 856 OutStreamer.AddBlankLine(); 857 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 858 I != E; ++I) { 859 MCSymbol *Name = Mang->getSymbol(I); 860 861 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 862 MCSymbol *Target = Mang->getSymbol(GV); 863 864 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 865 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 866 else if (I->hasWeakLinkage()) 867 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 868 else 869 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 870 871 EmitVisibility(Name, I->getVisibility()); 872 873 // Emit the directives as assignments aka .set: 874 OutStreamer.EmitAssignment(Name, 875 MCSymbolRefExpr::Create(Target, OutContext)); 876 } 877 } 878 879 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 880 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 881 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 882 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 883 MP->finishAssembly(*this); 884 885 // If we don't have any trampolines, then we don't require stack memory 886 // to be executable. Some targets have a directive to declare this. 887 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 888 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 889 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 890 OutStreamer.SwitchSection(S); 891 892 // Allow the target to emit any magic that it wants at the end of the file, 893 // after everything else has gone out. 894 EmitEndOfAsmFile(M); 895 896 delete Mang; Mang = 0; 897 MMI = 0; 898 899 OutStreamer.Finish(); 900 return false; 901} 902 903void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 904 this->MF = &MF; 905 // Get the function symbol. 906 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 907 908 if (isVerbose()) 909 LI = &getAnalysis<MachineLoopInfo>(); 910} 911 912namespace { 913 // SectionCPs - Keep track the alignment, constpool entries per Section. 914 struct SectionCPs { 915 const MCSection *S; 916 unsigned Alignment; 917 SmallVector<unsigned, 4> CPEs; 918 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 919 }; 920} 921 922/// EmitConstantPool - Print to the current output stream assembly 923/// representations of the constants in the constant pool MCP. This is 924/// used to print out constants which have been "spilled to memory" by 925/// the code generator. 926/// 927void AsmPrinter::EmitConstantPool() { 928 const MachineConstantPool *MCP = MF->getConstantPool(); 929 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 930 if (CP.empty()) return; 931 932 // Calculate sections for constant pool entries. We collect entries to go into 933 // the same section together to reduce amount of section switch statements. 934 SmallVector<SectionCPs, 4> CPSections; 935 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 936 const MachineConstantPoolEntry &CPE = CP[i]; 937 unsigned Align = CPE.getAlignment(); 938 939 SectionKind Kind; 940 switch (CPE.getRelocationInfo()) { 941 default: llvm_unreachable("Unknown section kind"); 942 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 943 case 1: 944 Kind = SectionKind::getReadOnlyWithRelLocal(); 945 break; 946 case 0: 947 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 948 case 4: Kind = SectionKind::getMergeableConst4(); break; 949 case 8: Kind = SectionKind::getMergeableConst8(); break; 950 case 16: Kind = SectionKind::getMergeableConst16();break; 951 default: Kind = SectionKind::getMergeableConst(); break; 952 } 953 } 954 955 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 956 957 // The number of sections are small, just do a linear search from the 958 // last section to the first. 959 bool Found = false; 960 unsigned SecIdx = CPSections.size(); 961 while (SecIdx != 0) { 962 if (CPSections[--SecIdx].S == S) { 963 Found = true; 964 break; 965 } 966 } 967 if (!Found) { 968 SecIdx = CPSections.size(); 969 CPSections.push_back(SectionCPs(S, Align)); 970 } 971 972 if (Align > CPSections[SecIdx].Alignment) 973 CPSections[SecIdx].Alignment = Align; 974 CPSections[SecIdx].CPEs.push_back(i); 975 } 976 977 // Now print stuff into the calculated sections. 978 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 979 OutStreamer.SwitchSection(CPSections[i].S); 980 EmitAlignment(Log2_32(CPSections[i].Alignment)); 981 982 unsigned Offset = 0; 983 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 984 unsigned CPI = CPSections[i].CPEs[j]; 985 MachineConstantPoolEntry CPE = CP[CPI]; 986 987 // Emit inter-object padding for alignment. 988 unsigned AlignMask = CPE.getAlignment() - 1; 989 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 990 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 991 992 const Type *Ty = CPE.getType(); 993 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 994 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 995 996 if (CPE.isMachineConstantPoolEntry()) 997 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 998 else 999 EmitGlobalConstant(CPE.Val.ConstVal); 1000 } 1001 } 1002} 1003 1004/// EmitJumpTableInfo - Print assembly representations of the jump tables used 1005/// by the current function to the current output stream. 1006/// 1007void AsmPrinter::EmitJumpTableInfo() { 1008 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1009 if (MJTI == 0) return; 1010 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1011 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1012 if (JT.empty()) return; 1013 1014 // Pick the directive to use to print the jump table entries, and switch to 1015 // the appropriate section. 1016 const Function *F = MF->getFunction(); 1017 bool JTInDiffSection = false; 1018 if (// In PIC mode, we need to emit the jump table to the same section as the 1019 // function body itself, otherwise the label differences won't make sense. 1020 // FIXME: Need a better predicate for this: what about custom entries? 1021 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1022 // We should also do if the section name is NULL or function is declared 1023 // in discardable section 1024 // FIXME: this isn't the right predicate, should be based on the MCSection 1025 // for the function. 1026 F->isWeakForLinker()) { 1027 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 1028 } else { 1029 // Otherwise, drop it in the readonly section. 1030 const MCSection *ReadOnlySection = 1031 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1032 OutStreamer.SwitchSection(ReadOnlySection); 1033 JTInDiffSection = true; 1034 } 1035 1036 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 1037 1038 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1039 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1040 1041 // If this jump table was deleted, ignore it. 1042 if (JTBBs.empty()) continue; 1043 1044 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1045 // .set directive for each unique entry. This reduces the number of 1046 // relocations the assembler will generate for the jump table. 1047 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1048 MAI->hasSetDirective()) { 1049 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1050 const TargetLowering *TLI = TM.getTargetLowering(); 1051 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1052 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1053 const MachineBasicBlock *MBB = JTBBs[ii]; 1054 if (!EmittedSets.insert(MBB)) continue; 1055 1056 // .set LJTSet, LBB32-base 1057 const MCExpr *LHS = 1058 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1059 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1060 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1061 } 1062 } 1063 1064 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1065 // before each jump table. The first label is never referenced, but tells 1066 // the assembler and linker the extents of the jump table object. The 1067 // second label is actually referenced by the code. 1068 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1069 // FIXME: This doesn't have to have any specific name, just any randomly 1070 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1071 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1072 1073 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1074 1075 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1076 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1077 } 1078} 1079 1080/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1081/// current stream. 1082void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1083 const MachineBasicBlock *MBB, 1084 unsigned UID) const { 1085 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1086 const MCExpr *Value = 0; 1087 switch (MJTI->getEntryKind()) { 1088 case MachineJumpTableInfo::EK_Inline: 1089 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1090 case MachineJumpTableInfo::EK_Custom32: 1091 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1092 OutContext); 1093 break; 1094 case MachineJumpTableInfo::EK_BlockAddress: 1095 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1096 // .word LBB123 1097 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1098 break; 1099 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1100 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1101 // with a relocation as gp-relative, e.g.: 1102 // .gprel32 LBB123 1103 MCSymbol *MBBSym = MBB->getSymbol(); 1104 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1105 return; 1106 } 1107 1108 case MachineJumpTableInfo::EK_LabelDifference32: { 1109 // EK_LabelDifference32 - Each entry is the address of the block minus 1110 // the address of the jump table. This is used for PIC jump tables where 1111 // gprel32 is not supported. e.g.: 1112 // .word LBB123 - LJTI1_2 1113 // If the .set directive is supported, this is emitted as: 1114 // .set L4_5_set_123, LBB123 - LJTI1_2 1115 // .word L4_5_set_123 1116 1117 // If we have emitted set directives for the jump table entries, print 1118 // them rather than the entries themselves. If we're emitting PIC, then 1119 // emit the table entries as differences between two text section labels. 1120 if (MAI->hasSetDirective()) { 1121 // If we used .set, reference the .set's symbol. 1122 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1123 OutContext); 1124 break; 1125 } 1126 // Otherwise, use the difference as the jump table entry. 1127 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1128 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1129 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1130 break; 1131 } 1132 } 1133 1134 assert(Value && "Unknown entry kind!"); 1135 1136 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1137 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1138} 1139 1140 1141/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1142/// special global used by LLVM. If so, emit it and return true, otherwise 1143/// do nothing and return false. 1144bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1145 if (GV->getName() == "llvm.used") { 1146 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1147 EmitLLVMUsedList(GV->getInitializer()); 1148 return true; 1149 } 1150 1151 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1152 if (GV->getSection() == "llvm.metadata" || 1153 GV->hasAvailableExternallyLinkage()) 1154 return true; 1155 1156 if (!GV->hasAppendingLinkage()) return false; 1157 1158 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1159 1160 const TargetData *TD = TM.getTargetData(); 1161 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1162 if (GV->getName() == "llvm.global_ctors") { 1163 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1164 EmitAlignment(Align); 1165 EmitXXStructorList(GV->getInitializer()); 1166 1167 if (TM.getRelocationModel() == Reloc::Static && 1168 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1169 StringRef Sym(".constructors_used"); 1170 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1171 MCSA_Reference); 1172 } 1173 return true; 1174 } 1175 1176 if (GV->getName() == "llvm.global_dtors") { 1177 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1178 EmitAlignment(Align); 1179 EmitXXStructorList(GV->getInitializer()); 1180 1181 if (TM.getRelocationModel() == Reloc::Static && 1182 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1183 StringRef Sym(".destructors_used"); 1184 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1185 MCSA_Reference); 1186 } 1187 return true; 1188 } 1189 1190 return false; 1191} 1192 1193/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1194/// global in the specified llvm.used list for which emitUsedDirectiveFor 1195/// is true, as being used with this directive. 1196void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1197 // Should be an array of 'i8*'. 1198 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1199 if (InitList == 0) return; 1200 1201 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1202 const GlobalValue *GV = 1203 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1204 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1205 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1206 } 1207} 1208 1209/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1210/// function pointers, ignoring the init priority. 1211void AsmPrinter::EmitXXStructorList(Constant *List) { 1212 // Should be an array of '{ int, void ()* }' structs. The first value is the 1213 // init priority, which we ignore. 1214 if (!isa<ConstantArray>(List)) return; 1215 ConstantArray *InitList = cast<ConstantArray>(List); 1216 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1217 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1218 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1219 1220 if (CS->getOperand(1)->isNullValue()) 1221 return; // Found a null terminator, exit printing. 1222 // Emit the function pointer. 1223 EmitGlobalConstant(CS->getOperand(1)); 1224 } 1225} 1226 1227//===--------------------------------------------------------------------===// 1228// Emission and print routines 1229// 1230 1231/// EmitInt8 - Emit a byte directive and value. 1232/// 1233void AsmPrinter::EmitInt8(int Value) const { 1234 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1235} 1236 1237/// EmitInt16 - Emit a short directive and value. 1238/// 1239void AsmPrinter::EmitInt16(int Value) const { 1240 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1241} 1242 1243/// EmitInt32 - Emit a long directive and value. 1244/// 1245void AsmPrinter::EmitInt32(int Value) const { 1246 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1247} 1248 1249/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1250/// in bytes of the directive is specified by Size and Hi/Lo specify the 1251/// labels. This implicitly uses .set if it is available. 1252void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1253 unsigned Size) const { 1254 // Get the Hi-Lo expression. 1255 const MCExpr *Diff = 1256 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1257 MCSymbolRefExpr::Create(Lo, OutContext), 1258 OutContext); 1259 1260 if (!MAI->hasSetDirective()) { 1261 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1262 return; 1263 } 1264 1265 // Otherwise, emit with .set (aka assignment). 1266 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1267 OutStreamer.EmitAssignment(SetLabel, Diff); 1268 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1269} 1270 1271/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1272/// where the size in bytes of the directive is specified by Size and Hi/Lo 1273/// specify the labels. This implicitly uses .set if it is available. 1274void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1275 const MCSymbol *Lo, unsigned Size) 1276 const { 1277 1278 // Emit Hi+Offset - Lo 1279 // Get the Hi+Offset expression. 1280 const MCExpr *Plus = 1281 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1282 MCConstantExpr::Create(Offset, OutContext), 1283 OutContext); 1284 1285 // Get the Hi+Offset-Lo expression. 1286 const MCExpr *Diff = 1287 MCBinaryExpr::CreateSub(Plus, 1288 MCSymbolRefExpr::Create(Lo, OutContext), 1289 OutContext); 1290 1291 if (!MAI->hasSetDirective()) 1292 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1293 else { 1294 // Otherwise, emit with .set (aka assignment). 1295 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1296 OutStreamer.EmitAssignment(SetLabel, Diff); 1297 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1298 } 1299} 1300 1301/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1302/// where the size in bytes of the directive is specified by Size and Label 1303/// specifies the label. This implicitly uses .set if it is available. 1304void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1305 unsigned Size) 1306 const { 1307 1308 // Emit Label+Offset 1309 const MCExpr *Plus = 1310 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1311 MCConstantExpr::Create(Offset, OutContext), 1312 OutContext); 1313 1314 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1315} 1316 1317 1318//===----------------------------------------------------------------------===// 1319 1320// EmitAlignment - Emit an alignment directive to the specified power of 1321// two boundary. For example, if you pass in 3 here, you will get an 8 1322// byte alignment. If a global value is specified, and if that global has 1323// an explicit alignment requested, it will override the alignment request 1324// if required for correctness. 1325// 1326void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1327 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1328 1329 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1330 1331 if (getCurrentSection()->getKind().isText()) 1332 OutStreamer.EmitCodeAlignment(1 << NumBits); 1333 else 1334 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1335} 1336 1337//===----------------------------------------------------------------------===// 1338// Constant emission. 1339//===----------------------------------------------------------------------===// 1340 1341/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1342/// 1343static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1344 MCContext &Ctx = AP.OutContext; 1345 1346 if (CV->isNullValue() || isa<UndefValue>(CV)) 1347 return MCConstantExpr::Create(0, Ctx); 1348 1349 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1350 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1351 1352 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1353 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1354 1355 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1356 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1357 1358 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1359 if (CE == 0) { 1360 llvm_unreachable("Unknown constant value to lower!"); 1361 return MCConstantExpr::Create(0, Ctx); 1362 } 1363 1364 switch (CE->getOpcode()) { 1365 default: 1366 // If the code isn't optimized, there may be outstanding folding 1367 // opportunities. Attempt to fold the expression using TargetData as a 1368 // last resort before giving up. 1369 if (Constant *C = 1370 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1371 if (C != CE) 1372 return LowerConstant(C, AP); 1373 1374 // Otherwise report the problem to the user. 1375 { 1376 std::string S; 1377 raw_string_ostream OS(S); 1378 OS << "Unsupported expression in static initializer: "; 1379 WriteAsOperand(OS, CE, /*PrintType=*/false, 1380 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1381 report_fatal_error(OS.str()); 1382 } 1383 return MCConstantExpr::Create(0, Ctx); 1384 case Instruction::GetElementPtr: { 1385 const TargetData &TD = *AP.TM.getTargetData(); 1386 // Generate a symbolic expression for the byte address 1387 const Constant *PtrVal = CE->getOperand(0); 1388 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1389 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1390 IdxVec.size()); 1391 1392 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1393 if (Offset == 0) 1394 return Base; 1395 1396 // Truncate/sext the offset to the pointer size. 1397 if (TD.getPointerSizeInBits() != 64) { 1398 int SExtAmount = 64-TD.getPointerSizeInBits(); 1399 Offset = (Offset << SExtAmount) >> SExtAmount; 1400 } 1401 1402 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1403 Ctx); 1404 } 1405 1406 case Instruction::Trunc: 1407 // We emit the value and depend on the assembler to truncate the generated 1408 // expression properly. This is important for differences between 1409 // blockaddress labels. Since the two labels are in the same function, it 1410 // is reasonable to treat their delta as a 32-bit value. 1411 // FALL THROUGH. 1412 case Instruction::BitCast: 1413 return LowerConstant(CE->getOperand(0), AP); 1414 1415 case Instruction::IntToPtr: { 1416 const TargetData &TD = *AP.TM.getTargetData(); 1417 // Handle casts to pointers by changing them into casts to the appropriate 1418 // integer type. This promotes constant folding and simplifies this code. 1419 Constant *Op = CE->getOperand(0); 1420 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1421 false/*ZExt*/); 1422 return LowerConstant(Op, AP); 1423 } 1424 1425 case Instruction::PtrToInt: { 1426 const TargetData &TD = *AP.TM.getTargetData(); 1427 // Support only foldable casts to/from pointers that can be eliminated by 1428 // changing the pointer to the appropriately sized integer type. 1429 Constant *Op = CE->getOperand(0); 1430 const Type *Ty = CE->getType(); 1431 1432 const MCExpr *OpExpr = LowerConstant(Op, AP); 1433 1434 // We can emit the pointer value into this slot if the slot is an 1435 // integer slot equal to the size of the pointer. 1436 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1437 return OpExpr; 1438 1439 // Otherwise the pointer is smaller than the resultant integer, mask off 1440 // the high bits so we are sure to get a proper truncation if the input is 1441 // a constant expr. 1442 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1443 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1444 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1445 } 1446 1447 // The MC library also has a right-shift operator, but it isn't consistently 1448 // signed or unsigned between different targets. 1449 case Instruction::Add: 1450 case Instruction::Sub: 1451 case Instruction::Mul: 1452 case Instruction::SDiv: 1453 case Instruction::SRem: 1454 case Instruction::Shl: 1455 case Instruction::And: 1456 case Instruction::Or: 1457 case Instruction::Xor: { 1458 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1459 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1460 switch (CE->getOpcode()) { 1461 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1462 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1463 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1464 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1465 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1466 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1467 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1468 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1469 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1470 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1471 } 1472 } 1473 } 1474} 1475 1476static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1477 AsmPrinter &AP); 1478 1479static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1480 AsmPrinter &AP) { 1481 if (AddrSpace != 0 || !CA->isString()) { 1482 // Not a string. Print the values in successive locations 1483 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1484 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1485 return; 1486 } 1487 1488 // Otherwise, it can be emitted as .ascii. 1489 SmallVector<char, 128> TmpVec; 1490 TmpVec.reserve(CA->getNumOperands()); 1491 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1492 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1493 1494 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1495} 1496 1497static void EmitGlobalConstantVector(const ConstantVector *CV, 1498 unsigned AddrSpace, AsmPrinter &AP) { 1499 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1500 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1501} 1502 1503static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1504 unsigned AddrSpace, AsmPrinter &AP) { 1505 // Print the fields in successive locations. Pad to align if needed! 1506 const TargetData *TD = AP.TM.getTargetData(); 1507 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1508 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1509 uint64_t SizeSoFar = 0; 1510 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1511 const Constant *Field = CS->getOperand(i); 1512 1513 // Check if padding is needed and insert one or more 0s. 1514 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1515 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1516 - Layout->getElementOffset(i)) - FieldSize; 1517 SizeSoFar += FieldSize + PadSize; 1518 1519 // Now print the actual field value. 1520 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1521 1522 // Insert padding - this may include padding to increase the size of the 1523 // current field up to the ABI size (if the struct is not packed) as well 1524 // as padding to ensure that the next field starts at the right offset. 1525 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1526 } 1527 assert(SizeSoFar == Layout->getSizeInBytes() && 1528 "Layout of constant struct may be incorrect!"); 1529} 1530 1531static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1532 AsmPrinter &AP) { 1533 // FP Constants are printed as integer constants to avoid losing 1534 // precision. 1535 if (CFP->getType()->isDoubleTy()) { 1536 if (AP.isVerbose()) { 1537 double Val = CFP->getValueAPF().convertToDouble(); 1538 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1539 } 1540 1541 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1542 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1543 return; 1544 } 1545 1546 if (CFP->getType()->isFloatTy()) { 1547 if (AP.isVerbose()) { 1548 float Val = CFP->getValueAPF().convertToFloat(); 1549 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1550 } 1551 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1552 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1553 return; 1554 } 1555 1556 if (CFP->getType()->isX86_FP80Ty()) { 1557 // all long double variants are printed as hex 1558 // API needed to prevent premature destruction 1559 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1560 const uint64_t *p = API.getRawData(); 1561 if (AP.isVerbose()) { 1562 // Convert to double so we can print the approximate val as a comment. 1563 APFloat DoubleVal = CFP->getValueAPF(); 1564 bool ignored; 1565 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1566 &ignored); 1567 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1568 << DoubleVal.convertToDouble() << '\n'; 1569 } 1570 1571 if (AP.TM.getTargetData()->isBigEndian()) { 1572 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1573 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1574 } else { 1575 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1576 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1577 } 1578 1579 // Emit the tail padding for the long double. 1580 const TargetData &TD = *AP.TM.getTargetData(); 1581 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1582 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1583 return; 1584 } 1585 1586 assert(CFP->getType()->isPPC_FP128Ty() && 1587 "Floating point constant type not handled"); 1588 // All long double variants are printed as hex 1589 // API needed to prevent premature destruction. 1590 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1591 const uint64_t *p = API.getRawData(); 1592 if (AP.TM.getTargetData()->isBigEndian()) { 1593 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1594 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1595 } else { 1596 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1597 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1598 } 1599} 1600 1601static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1602 unsigned AddrSpace, AsmPrinter &AP) { 1603 const TargetData *TD = AP.TM.getTargetData(); 1604 unsigned BitWidth = CI->getBitWidth(); 1605 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1606 1607 // We don't expect assemblers to support integer data directives 1608 // for more than 64 bits, so we emit the data in at most 64-bit 1609 // quantities at a time. 1610 const uint64_t *RawData = CI->getValue().getRawData(); 1611 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1612 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1613 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1614 } 1615} 1616 1617static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1618 AsmPrinter &AP) { 1619 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1620 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1621 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1622 } 1623 1624 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1625 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1626 switch (Size) { 1627 case 1: 1628 case 2: 1629 case 4: 1630 case 8: 1631 if (AP.isVerbose()) 1632 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1633 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1634 return; 1635 default: 1636 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1637 return; 1638 } 1639 } 1640 1641 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1642 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1643 1644 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1645 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1646 1647 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1648 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1649 1650 if (isa<ConstantPointerNull>(CV)) { 1651 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1652 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1653 return; 1654 } 1655 1656 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1657 return EmitGlobalConstantVector(V, AddrSpace, AP); 1658 1659 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1660 // thread the streamer with EmitValue. 1661 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1662 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1663 AddrSpace); 1664} 1665 1666/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1667void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1668 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1669 if (Size) 1670 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1671 else if (MAI->hasSubsectionsViaSymbols()) { 1672 // If the global has zero size, emit a single byte so that two labels don't 1673 // look like they are at the same location. 1674 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1675 } 1676} 1677 1678void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1679 // Target doesn't support this yet! 1680 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1681} 1682 1683void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1684 if (Offset > 0) 1685 OS << '+' << Offset; 1686 else if (Offset < 0) 1687 OS << Offset; 1688} 1689 1690//===----------------------------------------------------------------------===// 1691// Symbol Lowering Routines. 1692//===----------------------------------------------------------------------===// 1693 1694/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1695/// temporary label with the specified stem and unique ID. 1696MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1697 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1698 Name + Twine(ID)); 1699} 1700 1701/// GetTempSymbol - Return an assembler temporary label with the specified 1702/// stem. 1703MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1704 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1705 Name); 1706} 1707 1708 1709MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1710 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1711} 1712 1713MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1714 return MMI->getAddrLabelSymbol(BB); 1715} 1716 1717/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1718MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1719 return OutContext.GetOrCreateSymbol 1720 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1721 + "_" + Twine(CPID)); 1722} 1723 1724/// GetJTISymbol - Return the symbol for the specified jump table entry. 1725MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1726 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1727} 1728 1729/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1730/// FIXME: privatize to AsmPrinter. 1731MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1732 return OutContext.GetOrCreateSymbol 1733 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1734 Twine(UID) + "_set_" + Twine(MBBID)); 1735} 1736 1737/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1738/// global value name as its base, with the specified suffix, and where the 1739/// symbol is forced to have private linkage if ForcePrivate is true. 1740MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1741 StringRef Suffix, 1742 bool ForcePrivate) const { 1743 SmallString<60> NameStr; 1744 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1745 NameStr.append(Suffix.begin(), Suffix.end()); 1746 return OutContext.GetOrCreateSymbol(NameStr.str()); 1747} 1748 1749/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1750/// ExternalSymbol. 1751MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1752 SmallString<60> NameStr; 1753 Mang->getNameWithPrefix(NameStr, Sym); 1754 return OutContext.GetOrCreateSymbol(NameStr.str()); 1755} 1756 1757 1758 1759/// PrintParentLoopComment - Print comments about parent loops of this one. 1760static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1761 unsigned FunctionNumber) { 1762 if (Loop == 0) return; 1763 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1764 OS.indent(Loop->getLoopDepth()*2) 1765 << "Parent Loop BB" << FunctionNumber << "_" 1766 << Loop->getHeader()->getNumber() 1767 << " Depth=" << Loop->getLoopDepth() << '\n'; 1768} 1769 1770 1771/// PrintChildLoopComment - Print comments about child loops within 1772/// the loop for this basic block, with nesting. 1773static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1774 unsigned FunctionNumber) { 1775 // Add child loop information 1776 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1777 OS.indent((*CL)->getLoopDepth()*2) 1778 << "Child Loop BB" << FunctionNumber << "_" 1779 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1780 << '\n'; 1781 PrintChildLoopComment(OS, *CL, FunctionNumber); 1782 } 1783} 1784 1785/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1786static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1787 const MachineLoopInfo *LI, 1788 const AsmPrinter &AP) { 1789 // Add loop depth information 1790 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1791 if (Loop == 0) return; 1792 1793 MachineBasicBlock *Header = Loop->getHeader(); 1794 assert(Header && "No header for loop"); 1795 1796 // If this block is not a loop header, just print out what is the loop header 1797 // and return. 1798 if (Header != &MBB) { 1799 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1800 Twine(AP.getFunctionNumber())+"_" + 1801 Twine(Loop->getHeader()->getNumber())+ 1802 " Depth="+Twine(Loop->getLoopDepth())); 1803 return; 1804 } 1805 1806 // Otherwise, it is a loop header. Print out information about child and 1807 // parent loops. 1808 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1809 1810 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1811 1812 OS << "=>"; 1813 OS.indent(Loop->getLoopDepth()*2-2); 1814 1815 OS << "This "; 1816 if (Loop->empty()) 1817 OS << "Inner "; 1818 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1819 1820 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1821} 1822 1823 1824/// EmitBasicBlockStart - This method prints the label for the specified 1825/// MachineBasicBlock, an alignment (if present) and a comment describing 1826/// it if appropriate. 1827void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1828 // Emit an alignment directive for this block, if needed. 1829 if (unsigned Align = MBB->getAlignment()) 1830 EmitAlignment(Log2_32(Align)); 1831 1832 // If the block has its address taken, emit any labels that were used to 1833 // reference the block. It is possible that there is more than one label 1834 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1835 // the references were generated. 1836 if (MBB->hasAddressTaken()) { 1837 const BasicBlock *BB = MBB->getBasicBlock(); 1838 if (isVerbose()) 1839 OutStreamer.AddComment("Block address taken"); 1840 1841 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1842 1843 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1844 OutStreamer.EmitLabel(Syms[i]); 1845 } 1846 1847 // Print the main label for the block. 1848 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1849 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1850 if (const BasicBlock *BB = MBB->getBasicBlock()) 1851 if (BB->hasName()) 1852 OutStreamer.AddComment("%" + BB->getName()); 1853 1854 EmitBasicBlockLoopComments(*MBB, LI, *this); 1855 1856 // NOTE: Want this comment at start of line, don't emit with AddComment. 1857 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1858 Twine(MBB->getNumber()) + ":"); 1859 } 1860 } else { 1861 if (isVerbose()) { 1862 if (const BasicBlock *BB = MBB->getBasicBlock()) 1863 if (BB->hasName()) 1864 OutStreamer.AddComment("%" + BB->getName()); 1865 EmitBasicBlockLoopComments(*MBB, LI, *this); 1866 } 1867 1868 OutStreamer.EmitLabel(MBB->getSymbol()); 1869 } 1870} 1871 1872void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 1873 bool IsDefinition) const { 1874 MCSymbolAttr Attr = MCSA_Invalid; 1875 1876 switch (Visibility) { 1877 default: break; 1878 case GlobalValue::HiddenVisibility: 1879 if (IsDefinition) 1880 Attr = MAI->getHiddenVisibilityAttr(); 1881 else 1882 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 1883 break; 1884 case GlobalValue::ProtectedVisibility: 1885 Attr = MAI->getProtectedVisibilityAttr(); 1886 break; 1887 } 1888 1889 if (Attr != MCSA_Invalid) 1890 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1891} 1892 1893/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1894/// exactly one predecessor and the control transfer mechanism between 1895/// the predecessor and this block is a fall-through. 1896bool AsmPrinter:: 1897isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1898 // If this is a landing pad, it isn't a fall through. If it has no preds, 1899 // then nothing falls through to it. 1900 if (MBB->isLandingPad() || MBB->pred_empty()) 1901 return false; 1902 1903 // If there isn't exactly one predecessor, it can't be a fall through. 1904 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1905 ++PI2; 1906 if (PI2 != MBB->pred_end()) 1907 return false; 1908 1909 // The predecessor has to be immediately before this block. 1910 const MachineBasicBlock *Pred = *PI; 1911 1912 if (!Pred->isLayoutSuccessor(MBB)) 1913 return false; 1914 1915 // If the block is completely empty, then it definitely does fall through. 1916 if (Pred->empty()) 1917 return true; 1918 1919 // Otherwise, check the last instruction. 1920 const MachineInstr &LastInst = Pred->back(); 1921 return !LastInst.getDesc().isBarrier(); 1922} 1923 1924 1925 1926GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1927 if (!S->usesMetadata()) 1928 return 0; 1929 1930 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1931 gcp_map_type::iterator GCPI = GCMap.find(S); 1932 if (GCPI != GCMap.end()) 1933 return GCPI->second; 1934 1935 const char *Name = S->getName().c_str(); 1936 1937 for (GCMetadataPrinterRegistry::iterator 1938 I = GCMetadataPrinterRegistry::begin(), 1939 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1940 if (strcmp(Name, I->getName()) == 0) { 1941 GCMetadataPrinter *GMP = I->instantiate(); 1942 GMP->S = S; 1943 GCMap.insert(std::make_pair(S, GMP)); 1944 return GMP; 1945 } 1946 1947 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1948 return 0; 1949} 1950 1951