AsmPrinter.cpp revision 5b23b7fe3150b2050d6fcd6981d64f30930fd3ef
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/TargetOptions.h" 42#include "llvm/Target/TargetRegisterInfo.h" 43#include "llvm/Assembly/Writer.h" 44#include "llvm/ADT/SmallString.h" 45#include "llvm/ADT/Statistic.h" 46#include "llvm/Support/ErrorHandling.h" 47#include "llvm/Support/Format.h" 48#include "llvm/Support/Timer.h" 49using namespace llvm; 50 51static const char *DWARFGroupName = "DWARF Emission"; 52static const char *DbgTimerName = "DWARF Debug Writer"; 53static const char *EHTimerName = "DWARF Exception Writer"; 54 55STATISTIC(EmittedInsts, "Number of machine instrs printed"); 56 57char AsmPrinter::ID = 0; 58 59typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 60static gcp_map_type &getGCMap(void *&P) { 61 if (P == 0) 62 P = new gcp_map_type(); 63 return *(gcp_map_type*)P; 64} 65 66 67/// getGVAlignmentLog2 - Return the alignment to use for the specified global 68/// value in log2 form. This rounds up to the preferred alignment if possible 69/// and legal. 70static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 71 unsigned InBits = 0) { 72 unsigned NumBits = 0; 73 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 74 NumBits = TD.getPreferredAlignmentLog(GVar); 75 76 // If InBits is specified, round it to it. 77 if (InBits > NumBits) 78 NumBits = InBits; 79 80 // If the GV has a specified alignment, take it into account. 81 if (GV->getAlignment() == 0) 82 return NumBits; 83 84 unsigned GVAlign = Log2_32(GV->getAlignment()); 85 86 // If the GVAlign is larger than NumBits, or if we are required to obey 87 // NumBits because the GV has an assigned section, obey it. 88 if (GVAlign > NumBits || GV->hasSection()) 89 NumBits = GVAlign; 90 return NumBits; 91} 92 93 94 95 96AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 97 : MachineFunctionPass(ID), 98 TM(tm), MAI(tm.getMCAsmInfo()), 99 OutContext(Streamer.getContext()), 100 OutStreamer(Streamer), 101 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 102 DD = 0; DE = 0; MMI = 0; LI = 0; 103 GCMetadataPrinters = 0; 104 VerboseAsm = Streamer.isVerboseAsm(); 105} 106 107AsmPrinter::~AsmPrinter() { 108 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 109 110 if (GCMetadataPrinters != 0) { 111 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 112 113 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 114 delete I->second; 115 delete &GCMap; 116 GCMetadataPrinters = 0; 117 } 118 119 delete &OutStreamer; 120} 121 122/// getFunctionNumber - Return a unique ID for the current function. 123/// 124unsigned AsmPrinter::getFunctionNumber() const { 125 return MF->getFunctionNumber(); 126} 127 128const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 129 return TM.getTargetLowering()->getObjFileLowering(); 130} 131 132 133/// getTargetData - Return information about data layout. 134const TargetData &AsmPrinter::getTargetData() const { 135 return *TM.getTargetData(); 136} 137 138/// getCurrentSection() - Return the current section we are emitting to. 139const MCSection *AsmPrinter::getCurrentSection() const { 140 return OutStreamer.getCurrentSection(); 141} 142 143 144 145void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 146 AU.setPreservesAll(); 147 MachineFunctionPass::getAnalysisUsage(AU); 148 AU.addRequired<MachineModuleInfo>(); 149 AU.addRequired<GCModuleInfo>(); 150 if (isVerbose()) 151 AU.addRequired<MachineLoopInfo>(); 152} 153 154bool AsmPrinter::doInitialization(Module &M) { 155 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 156 MMI->AnalyzeModule(M); 157 158 // Initialize TargetLoweringObjectFile. 159 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 160 .Initialize(OutContext, TM); 161 162 Mang = new Mangler(OutContext, *TM.getTargetData()); 163 164 // Allow the target to emit any magic that it wants at the start of the file. 165 EmitStartOfAsmFile(M); 166 167 // Very minimal debug info. It is ignored if we emit actual debug info. If we 168 // don't, this at least helps the user find where a global came from. 169 if (MAI->hasSingleParameterDotFile()) { 170 // .file "foo.c" 171 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 172 } 173 174 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 175 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 176 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 177 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 178 MP->beginAssembly(*this); 179 180 // Emit module-level inline asm if it exists. 181 if (!M.getModuleInlineAsm().empty()) { 182 OutStreamer.AddComment("Start of file scope inline assembly"); 183 OutStreamer.AddBlankLine(); 184 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 185 OutStreamer.AddComment("End of file scope inline assembly"); 186 OutStreamer.AddBlankLine(); 187 } 188 189 if (MAI->doesSupportDebugInformation()) 190 DD = new DwarfDebug(this, &M); 191 192 switch (MAI->getExceptionHandlingType()) { 193 case ExceptionHandling::None: 194 return false; 195 case ExceptionHandling::SjLj: 196 case ExceptionHandling::DwarfCFI: 197 DE = new DwarfCFIException(this); 198 return false; 199 case ExceptionHandling::ARM: 200 DE = new ARMException(this); 201 return false; 202 } 203 204 llvm_unreachable("Unknown exception type."); 205} 206 207void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 208 switch ((GlobalValue::LinkageTypes)Linkage) { 209 case GlobalValue::CommonLinkage: 210 case GlobalValue::LinkOnceAnyLinkage: 211 case GlobalValue::LinkOnceODRLinkage: 212 case GlobalValue::WeakAnyLinkage: 213 case GlobalValue::WeakODRLinkage: 214 case GlobalValue::LinkerPrivateWeakLinkage: 215 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 216 if (MAI->getWeakDefDirective() != 0) { 217 // .globl _foo 218 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 219 220 if ((GlobalValue::LinkageTypes)Linkage != 221 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 222 // .weak_definition _foo 223 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 224 else 225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 226 } else if (MAI->getLinkOnceDirective() != 0) { 227 // .globl _foo 228 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 229 //NOTE: linkonce is handled by the section the symbol was assigned to. 230 } else { 231 // .weak _foo 232 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 233 } 234 break; 235 case GlobalValue::DLLExportLinkage: 236 case GlobalValue::AppendingLinkage: 237 // FIXME: appending linkage variables should go into a section of 238 // their name or something. For now, just emit them as external. 239 case GlobalValue::ExternalLinkage: 240 // If external or appending, declare as a global symbol. 241 // .globl _foo 242 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 243 break; 244 case GlobalValue::PrivateLinkage: 245 case GlobalValue::InternalLinkage: 246 case GlobalValue::LinkerPrivateLinkage: 247 break; 248 default: 249 llvm_unreachable("Unknown linkage type!"); 250 } 251} 252 253 254/// EmitGlobalVariable - Emit the specified global variable to the .s file. 255void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 256 if (GV->hasInitializer()) { 257 // Check to see if this is a special global used by LLVM, if so, emit it. 258 if (EmitSpecialLLVMGlobal(GV)) 259 return; 260 261 if (isVerbose()) { 262 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 263 /*PrintType=*/false, GV->getParent()); 264 OutStreamer.GetCommentOS() << '\n'; 265 } 266 } 267 268 MCSymbol *GVSym = Mang->getSymbol(GV); 269 EmitVisibility(GVSym, GV->getVisibility()); 270 271 if (!GV->hasInitializer()) // External globals require no extra code. 272 return; 273 274 if (MAI->hasDotTypeDotSizeDirective()) 275 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 276 277 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 278 279 const TargetData *TD = TM.getTargetData(); 280 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 281 282 // If the alignment is specified, we *must* obey it. Overaligning a global 283 // with a specified alignment is a prompt way to break globals emitted to 284 // sections and expected to be contiguous (e.g. ObjC metadata). 285 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 286 287 // Handle common and BSS local symbols (.lcomm). 288 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 289 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 290 291 // Handle common symbols. 292 if (GVKind.isCommon()) { 293 unsigned Align = 1 << AlignLog; 294 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 295 Align = 0; 296 297 // .comm _foo, 42, 4 298 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 299 return; 300 } 301 302 // Handle local BSS symbols. 303 if (MAI->hasMachoZeroFillDirective()) { 304 const MCSection *TheSection = 305 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 306 // .zerofill __DATA, __bss, _foo, 400, 5 307 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 308 return; 309 } 310 311 if (MAI->hasLCOMMDirective()) { 312 // .lcomm _foo, 42 313 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 314 return; 315 } 316 317 unsigned Align = 1 << AlignLog; 318 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 319 Align = 0; 320 321 // .local _foo 322 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 323 // .comm _foo, 42, 4 324 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 325 return; 326 } 327 328 const MCSection *TheSection = 329 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 330 331 // Handle the zerofill directive on darwin, which is a special form of BSS 332 // emission. 333 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 334 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 335 336 // .globl _foo 337 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 338 // .zerofill __DATA, __common, _foo, 400, 5 339 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 340 return; 341 } 342 343 // Handle thread local data for mach-o which requires us to output an 344 // additional structure of data and mangle the original symbol so that we 345 // can reference it later. 346 // 347 // TODO: This should become an "emit thread local global" method on TLOF. 348 // All of this macho specific stuff should be sunk down into TLOFMachO and 349 // stuff like "TLSExtraDataSection" should no longer be part of the parent 350 // TLOF class. This will also make it more obvious that stuff like 351 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 352 // specific code. 353 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 354 // Emit the .tbss symbol 355 MCSymbol *MangSym = 356 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 357 358 if (GVKind.isThreadBSS()) 359 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 360 else if (GVKind.isThreadData()) { 361 OutStreamer.SwitchSection(TheSection); 362 363 EmitAlignment(AlignLog, GV); 364 OutStreamer.EmitLabel(MangSym); 365 366 EmitGlobalConstant(GV->getInitializer()); 367 } 368 369 OutStreamer.AddBlankLine(); 370 371 // Emit the variable struct for the runtime. 372 const MCSection *TLVSect 373 = getObjFileLowering().getTLSExtraDataSection(); 374 375 OutStreamer.SwitchSection(TLVSect); 376 // Emit the linkage here. 377 EmitLinkage(GV->getLinkage(), GVSym); 378 OutStreamer.EmitLabel(GVSym); 379 380 // Three pointers in size: 381 // - __tlv_bootstrap - used to make sure support exists 382 // - spare pointer, used when mapped by the runtime 383 // - pointer to mangled symbol above with initializer 384 unsigned PtrSize = TD->getPointerSizeInBits()/8; 385 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 386 PtrSize, 0); 387 OutStreamer.EmitIntValue(0, PtrSize, 0); 388 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 389 390 OutStreamer.AddBlankLine(); 391 return; 392 } 393 394 OutStreamer.SwitchSection(TheSection); 395 396 EmitLinkage(GV->getLinkage(), GVSym); 397 EmitAlignment(AlignLog, GV); 398 399 OutStreamer.EmitLabel(GVSym); 400 401 EmitGlobalConstant(GV->getInitializer()); 402 403 if (MAI->hasDotTypeDotSizeDirective()) 404 // .size foo, 42 405 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 406 407 OutStreamer.AddBlankLine(); 408} 409 410/// EmitFunctionHeader - This method emits the header for the current 411/// function. 412void AsmPrinter::EmitFunctionHeader() { 413 // Print out constants referenced by the function 414 EmitConstantPool(); 415 416 // Print the 'header' of function. 417 const Function *F = MF->getFunction(); 418 419 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 420 EmitVisibility(CurrentFnSym, F->getVisibility()); 421 422 EmitLinkage(F->getLinkage(), CurrentFnSym); 423 EmitAlignment(MF->getAlignment(), F); 424 425 if (MAI->hasDotTypeDotSizeDirective()) 426 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 427 428 if (isVerbose()) { 429 WriteAsOperand(OutStreamer.GetCommentOS(), F, 430 /*PrintType=*/false, F->getParent()); 431 OutStreamer.GetCommentOS() << '\n'; 432 } 433 434 // Emit the CurrentFnSym. This is a virtual function to allow targets to 435 // do their wild and crazy things as required. 436 EmitFunctionEntryLabel(); 437 438 // If the function had address-taken blocks that got deleted, then we have 439 // references to the dangling symbols. Emit them at the start of the function 440 // so that we don't get references to undefined symbols. 441 std::vector<MCSymbol*> DeadBlockSyms; 442 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 443 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 444 OutStreamer.AddComment("Address taken block that was later removed"); 445 OutStreamer.EmitLabel(DeadBlockSyms[i]); 446 } 447 448 // Add some workaround for linkonce linkage on Cygwin\MinGW. 449 if (MAI->getLinkOnceDirective() != 0 && 450 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 451 // FIXME: What is this? 452 MCSymbol *FakeStub = 453 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 454 CurrentFnSym->getName()); 455 OutStreamer.EmitLabel(FakeStub); 456 } 457 458 // Emit pre-function debug and/or EH information. 459 if (DE) { 460 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 461 DE->BeginFunction(MF); 462 } 463 if (DD) { 464 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 465 DD->beginFunction(MF); 466 } 467} 468 469/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 470/// function. This can be overridden by targets as required to do custom stuff. 471void AsmPrinter::EmitFunctionEntryLabel() { 472 // The function label could have already been emitted if two symbols end up 473 // conflicting due to asm renaming. Detect this and emit an error. 474 if (CurrentFnSym->isUndefined()) 475 return OutStreamer.EmitLabel(CurrentFnSym); 476 477 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 478 "' label emitted multiple times to assembly file"); 479} 480 481 482/// EmitComments - Pretty-print comments for instructions. 483static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 484 const MachineFunction *MF = MI.getParent()->getParent(); 485 const TargetMachine &TM = MF->getTarget(); 486 487 // Check for spills and reloads 488 int FI; 489 490 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 491 492 // We assume a single instruction only has a spill or reload, not 493 // both. 494 const MachineMemOperand *MMO; 495 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 496 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 497 MMO = *MI.memoperands_begin(); 498 CommentOS << MMO->getSize() << "-byte Reload\n"; 499 } 500 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 501 if (FrameInfo->isSpillSlotObjectIndex(FI)) 502 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 503 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 504 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 505 MMO = *MI.memoperands_begin(); 506 CommentOS << MMO->getSize() << "-byte Spill\n"; 507 } 508 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 509 if (FrameInfo->isSpillSlotObjectIndex(FI)) 510 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 511 } 512 513 // Check for spill-induced copies 514 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 515 CommentOS << " Reload Reuse\n"; 516} 517 518/// EmitImplicitDef - This method emits the specified machine instruction 519/// that is an implicit def. 520static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 521 unsigned RegNo = MI->getOperand(0).getReg(); 522 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 523 AP.TM.getRegisterInfo()->getName(RegNo)); 524 AP.OutStreamer.AddBlankLine(); 525} 526 527static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 528 std::string Str = "kill:"; 529 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 530 const MachineOperand &Op = MI->getOperand(i); 531 assert(Op.isReg() && "KILL instruction must have only register operands"); 532 Str += ' '; 533 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 534 Str += (Op.isDef() ? "<def>" : "<kill>"); 535 } 536 AP.OutStreamer.AddComment(Str); 537 AP.OutStreamer.AddBlankLine(); 538} 539 540/// EmitDebugValueComment - This method handles the target-independent form 541/// of DBG_VALUE, returning true if it was able to do so. A false return 542/// means the target will need to handle MI in EmitInstruction. 543static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 544 // This code handles only the 3-operand target-independent form. 545 if (MI->getNumOperands() != 3) 546 return false; 547 548 SmallString<128> Str; 549 raw_svector_ostream OS(Str); 550 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 551 552 // cast away const; DIetc do not take const operands for some reason. 553 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 554 if (V.getContext().isSubprogram()) 555 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 556 OS << V.getName() << " <- "; 557 558 // Register or immediate value. Register 0 means undef. 559 if (MI->getOperand(0).isFPImm()) { 560 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 561 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 562 OS << (double)APF.convertToFloat(); 563 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 564 OS << APF.convertToDouble(); 565 } else { 566 // There is no good way to print long double. Convert a copy to 567 // double. Ah well, it's only a comment. 568 bool ignored; 569 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 570 &ignored); 571 OS << "(long double) " << APF.convertToDouble(); 572 } 573 } else if (MI->getOperand(0).isImm()) { 574 OS << MI->getOperand(0).getImm(); 575 } else { 576 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 577 if (MI->getOperand(0).getReg() == 0) { 578 // Suppress offset, it is not meaningful here. 579 OS << "undef"; 580 // NOTE: Want this comment at start of line, don't emit with AddComment. 581 AP.OutStreamer.EmitRawText(OS.str()); 582 return true; 583 } 584 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 585 } 586 587 OS << '+' << MI->getOperand(1).getImm(); 588 // NOTE: Want this comment at start of line, don't emit with AddComment. 589 AP.OutStreamer.EmitRawText(OS.str()); 590 return true; 591} 592 593AsmPrinter::CFIMoveType AsmPrinter::needsCFIMoves() { 594 if (MAI->getExceptionHandlingType() == ExceptionHandling::DwarfCFI && 595 MF->getFunction()->needsUnwindTableEntry()) 596 return CFI_M_EH; 597 598 if (MMI->hasDebugInfo()) 599 return CFI_M_Debug; 600 601 return CFI_M_None; 602} 603 604void AsmPrinter::emitPrologLabel(const MachineInstr &MI) { 605 MCSymbol *Label = MI.getOperand(0).getMCSymbol(); 606 607 if (MAI->getExceptionHandlingType() != ExceptionHandling::DwarfCFI) 608 return; 609 610 if (needsCFIMoves() == CFI_M_None) 611 return; 612 613 MachineModuleInfo &MMI = MF->getMMI(); 614 std::vector<MachineMove> &Moves = MMI.getFrameMoves(); 615 bool FoundOne = false; 616 (void)FoundOne; 617 for (std::vector<MachineMove>::iterator I = Moves.begin(), 618 E = Moves.end(); I != E; ++I) { 619 if (I->getLabel() == Label) { 620 EmitCFIFrameMove(*I); 621 FoundOne = true; 622 } 623 } 624 assert(FoundOne); 625} 626 627/// EmitFunctionBody - This method emits the body and trailer for a 628/// function. 629void AsmPrinter::EmitFunctionBody() { 630 // Emit target-specific gunk before the function body. 631 EmitFunctionBodyStart(); 632 633 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 634 635 // Print out code for the function. 636 bool HasAnyRealCode = false; 637 const MachineInstr *LastMI = 0; 638 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 639 I != E; ++I) { 640 // Print a label for the basic block. 641 EmitBasicBlockStart(I); 642 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 643 II != IE; ++II) { 644 LastMI = II; 645 646 // Print the assembly for the instruction. 647 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 648 !II->isDebugValue()) { 649 HasAnyRealCode = true; 650 ++EmittedInsts; 651 } 652 653 if (ShouldPrintDebugScopes) { 654 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 655 DD->beginInstruction(II); 656 } 657 658 if (isVerbose()) 659 EmitComments(*II, OutStreamer.GetCommentOS()); 660 661 switch (II->getOpcode()) { 662 case TargetOpcode::PROLOG_LABEL: 663 emitPrologLabel(*II); 664 break; 665 666 case TargetOpcode::EH_LABEL: 667 case TargetOpcode::GC_LABEL: 668 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 669 break; 670 case TargetOpcode::INLINEASM: 671 EmitInlineAsm(II); 672 break; 673 case TargetOpcode::DBG_VALUE: 674 if (isVerbose()) { 675 if (!EmitDebugValueComment(II, *this)) 676 EmitInstruction(II); 677 } 678 break; 679 case TargetOpcode::IMPLICIT_DEF: 680 if (isVerbose()) EmitImplicitDef(II, *this); 681 break; 682 case TargetOpcode::KILL: 683 if (isVerbose()) EmitKill(II, *this); 684 break; 685 default: 686 if (!TM.hasMCUseLoc()) 687 MCLineEntry::Make(&OutStreamer, getCurrentSection()); 688 689 EmitInstruction(II); 690 break; 691 } 692 693 if (ShouldPrintDebugScopes) { 694 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 695 DD->endInstruction(II); 696 } 697 } 698 } 699 700 // If the last instruction was a prolog label, then we have a situation where 701 // we emitted a prolog but no function body. This results in the ending prolog 702 // label equaling the end of function label and an invalid "row" in the 703 // FDE. We need to emit a noop in this situation so that the FDE's rows are 704 // valid. 705 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 706 707 // If the function is empty and the object file uses .subsections_via_symbols, 708 // then we need to emit *something* to the function body to prevent the 709 // labels from collapsing together. Just emit a noop. 710 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 711 MCInst Noop; 712 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 713 if (Noop.getOpcode()) { 714 OutStreamer.AddComment("avoids zero-length function"); 715 OutStreamer.EmitInstruction(Noop); 716 } else // Target not mc-ized yet. 717 OutStreamer.EmitRawText(StringRef("\tnop\n")); 718 } 719 720 // Emit target-specific gunk after the function body. 721 EmitFunctionBodyEnd(); 722 723 // If the target wants a .size directive for the size of the function, emit 724 // it. 725 if (MAI->hasDotTypeDotSizeDirective()) { 726 // Create a symbol for the end of function, so we can get the size as 727 // difference between the function label and the temp label. 728 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 729 OutStreamer.EmitLabel(FnEndLabel); 730 731 const MCExpr *SizeExp = 732 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 733 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 734 OutContext); 735 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 736 } 737 738 // Emit post-function debug information. 739 if (DD) { 740 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 741 DD->endFunction(MF); 742 } 743 if (DE) { 744 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 745 DE->EndFunction(); 746 } 747 MMI->EndFunction(); 748 749 // Print out jump tables referenced by the function. 750 EmitJumpTableInfo(); 751 752 OutStreamer.AddBlankLine(); 753} 754 755/// getDebugValueLocation - Get location information encoded by DBG_VALUE 756/// operands. 757MachineLocation AsmPrinter:: 758getDebugValueLocation(const MachineInstr *MI) const { 759 // Target specific DBG_VALUE instructions are handled by each target. 760 return MachineLocation(); 761} 762 763/// EmitDwarfRegOp - Emit dwarf register operation. 764void AsmPrinter::EmitDwarfRegOp(const MachineLocation &MLoc) const { 765 const TargetRegisterInfo *TRI = TM.getRegisterInfo(); 766 unsigned Reg = TRI->getDwarfRegNum(MLoc.getReg(), false); 767 if (int Offset = MLoc.getOffset()) { 768 if (Reg < 32) { 769 OutStreamer.AddComment( 770 dwarf::OperationEncodingString(dwarf::DW_OP_breg0 + Reg)); 771 EmitInt8(dwarf::DW_OP_breg0 + Reg); 772 } else { 773 OutStreamer.AddComment("DW_OP_bregx"); 774 EmitInt8(dwarf::DW_OP_bregx); 775 OutStreamer.AddComment(Twine(Reg)); 776 EmitULEB128(Reg); 777 } 778 EmitSLEB128(Offset); 779 } else { 780 if (Reg < 32) { 781 OutStreamer.AddComment( 782 dwarf::OperationEncodingString(dwarf::DW_OP_reg0 + Reg)); 783 EmitInt8(dwarf::DW_OP_reg0 + Reg); 784 } else { 785 OutStreamer.AddComment("DW_OP_regx"); 786 EmitInt8(dwarf::DW_OP_regx); 787 OutStreamer.AddComment(Twine(Reg)); 788 EmitULEB128(Reg); 789 } 790 } 791} 792 793bool AsmPrinter::doFinalization(Module &M) { 794 // Emit global variables. 795 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 796 I != E; ++I) 797 EmitGlobalVariable(I); 798 799 // Emit visibility info for declarations 800 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 801 const Function &F = *I; 802 if (!F.isDeclaration()) 803 continue; 804 GlobalValue::VisibilityTypes V = F.getVisibility(); 805 if (V == GlobalValue::DefaultVisibility) 806 continue; 807 808 MCSymbol *Name = Mang->getSymbol(&F); 809 EmitVisibility(Name, V, false); 810 } 811 812 // Finalize debug and EH information. 813 if (DE) { 814 { 815 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 816 DE->EndModule(); 817 } 818 delete DE; DE = 0; 819 } 820 if (DD) { 821 { 822 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 823 DD->endModule(); 824 } 825 delete DD; DD = 0; 826 } 827 828 // If the target wants to know about weak references, print them all. 829 if (MAI->getWeakRefDirective()) { 830 // FIXME: This is not lazy, it would be nice to only print weak references 831 // to stuff that is actually used. Note that doing so would require targets 832 // to notice uses in operands (due to constant exprs etc). This should 833 // happen with the MC stuff eventually. 834 835 // Print out module-level global variables here. 836 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 837 I != E; ++I) { 838 if (!I->hasExternalWeakLinkage()) continue; 839 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 840 } 841 842 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 843 if (!I->hasExternalWeakLinkage()) continue; 844 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 845 } 846 } 847 848 if (MAI->hasSetDirective()) { 849 OutStreamer.AddBlankLine(); 850 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 851 I != E; ++I) { 852 MCSymbol *Name = Mang->getSymbol(I); 853 854 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 855 MCSymbol *Target = Mang->getSymbol(GV); 856 857 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 858 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 859 else if (I->hasWeakLinkage()) 860 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 861 else 862 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 863 864 EmitVisibility(Name, I->getVisibility()); 865 866 // Emit the directives as assignments aka .set: 867 OutStreamer.EmitAssignment(Name, 868 MCSymbolRefExpr::Create(Target, OutContext)); 869 } 870 } 871 872 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 873 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 874 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 875 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 876 MP->finishAssembly(*this); 877 878 // If we don't have any trampolines, then we don't require stack memory 879 // to be executable. Some targets have a directive to declare this. 880 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 881 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 882 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 883 OutStreamer.SwitchSection(S); 884 885 // Allow the target to emit any magic that it wants at the end of the file, 886 // after everything else has gone out. 887 EmitEndOfAsmFile(M); 888 889 delete Mang; Mang = 0; 890 MMI = 0; 891 892 OutStreamer.Finish(); 893 return false; 894} 895 896void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 897 this->MF = &MF; 898 // Get the function symbol. 899 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 900 901 if (isVerbose()) 902 LI = &getAnalysis<MachineLoopInfo>(); 903} 904 905namespace { 906 // SectionCPs - Keep track the alignment, constpool entries per Section. 907 struct SectionCPs { 908 const MCSection *S; 909 unsigned Alignment; 910 SmallVector<unsigned, 4> CPEs; 911 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 912 }; 913} 914 915/// EmitConstantPool - Print to the current output stream assembly 916/// representations of the constants in the constant pool MCP. This is 917/// used to print out constants which have been "spilled to memory" by 918/// the code generator. 919/// 920void AsmPrinter::EmitConstantPool() { 921 const MachineConstantPool *MCP = MF->getConstantPool(); 922 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 923 if (CP.empty()) return; 924 925 // Calculate sections for constant pool entries. We collect entries to go into 926 // the same section together to reduce amount of section switch statements. 927 SmallVector<SectionCPs, 4> CPSections; 928 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 929 const MachineConstantPoolEntry &CPE = CP[i]; 930 unsigned Align = CPE.getAlignment(); 931 932 SectionKind Kind; 933 switch (CPE.getRelocationInfo()) { 934 default: llvm_unreachable("Unknown section kind"); 935 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 936 case 1: 937 Kind = SectionKind::getReadOnlyWithRelLocal(); 938 break; 939 case 0: 940 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 941 case 4: Kind = SectionKind::getMergeableConst4(); break; 942 case 8: Kind = SectionKind::getMergeableConst8(); break; 943 case 16: Kind = SectionKind::getMergeableConst16();break; 944 default: Kind = SectionKind::getMergeableConst(); break; 945 } 946 } 947 948 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 949 950 // The number of sections are small, just do a linear search from the 951 // last section to the first. 952 bool Found = false; 953 unsigned SecIdx = CPSections.size(); 954 while (SecIdx != 0) { 955 if (CPSections[--SecIdx].S == S) { 956 Found = true; 957 break; 958 } 959 } 960 if (!Found) { 961 SecIdx = CPSections.size(); 962 CPSections.push_back(SectionCPs(S, Align)); 963 } 964 965 if (Align > CPSections[SecIdx].Alignment) 966 CPSections[SecIdx].Alignment = Align; 967 CPSections[SecIdx].CPEs.push_back(i); 968 } 969 970 // Now print stuff into the calculated sections. 971 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 972 OutStreamer.SwitchSection(CPSections[i].S); 973 EmitAlignment(Log2_32(CPSections[i].Alignment)); 974 975 unsigned Offset = 0; 976 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 977 unsigned CPI = CPSections[i].CPEs[j]; 978 MachineConstantPoolEntry CPE = CP[CPI]; 979 980 // Emit inter-object padding for alignment. 981 unsigned AlignMask = CPE.getAlignment() - 1; 982 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 983 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 984 985 const Type *Ty = CPE.getType(); 986 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 987 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 988 989 if (CPE.isMachineConstantPoolEntry()) 990 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 991 else 992 EmitGlobalConstant(CPE.Val.ConstVal); 993 } 994 } 995} 996 997/// EmitJumpTableInfo - Print assembly representations of the jump tables used 998/// by the current function to the current output stream. 999/// 1000void AsmPrinter::EmitJumpTableInfo() { 1001 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 1002 if (MJTI == 0) return; 1003 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 1004 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1005 if (JT.empty()) return; 1006 1007 // Pick the directive to use to print the jump table entries, and switch to 1008 // the appropriate section. 1009 const Function *F = MF->getFunction(); 1010 bool JTInDiffSection = false; 1011 if (// In PIC mode, we need to emit the jump table to the same section as the 1012 // function body itself, otherwise the label differences won't make sense. 1013 // FIXME: Need a better predicate for this: what about custom entries? 1014 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 1015 // We should also do if the section name is NULL or function is declared 1016 // in discardable section 1017 // FIXME: this isn't the right predicate, should be based on the MCSection 1018 // for the function. 1019 F->isWeakForLinker()) { 1020 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 1021 } else { 1022 // Otherwise, drop it in the readonly section. 1023 const MCSection *ReadOnlySection = 1024 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 1025 OutStreamer.SwitchSection(ReadOnlySection); 1026 JTInDiffSection = true; 1027 } 1028 1029 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 1030 1031 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 1032 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 1033 1034 // If this jump table was deleted, ignore it. 1035 if (JTBBs.empty()) continue; 1036 1037 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 1038 // .set directive for each unique entry. This reduces the number of 1039 // relocations the assembler will generate for the jump table. 1040 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 1041 MAI->hasSetDirective()) { 1042 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1043 const TargetLowering *TLI = TM.getTargetLowering(); 1044 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1045 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1046 const MachineBasicBlock *MBB = JTBBs[ii]; 1047 if (!EmittedSets.insert(MBB)) continue; 1048 1049 // .set LJTSet, LBB32-base 1050 const MCExpr *LHS = 1051 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1052 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1053 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1054 } 1055 } 1056 1057 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1058 // before each jump table. The first label is never referenced, but tells 1059 // the assembler and linker the extents of the jump table object. The 1060 // second label is actually referenced by the code. 1061 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1062 // FIXME: This doesn't have to have any specific name, just any randomly 1063 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1064 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1065 1066 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1067 1068 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1069 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1070 } 1071} 1072 1073/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1074/// current stream. 1075void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1076 const MachineBasicBlock *MBB, 1077 unsigned UID) const { 1078 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1079 const MCExpr *Value = 0; 1080 switch (MJTI->getEntryKind()) { 1081 case MachineJumpTableInfo::EK_Inline: 1082 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1083 case MachineJumpTableInfo::EK_Custom32: 1084 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1085 OutContext); 1086 break; 1087 case MachineJumpTableInfo::EK_BlockAddress: 1088 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1089 // .word LBB123 1090 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1091 break; 1092 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1093 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1094 // with a relocation as gp-relative, e.g.: 1095 // .gprel32 LBB123 1096 MCSymbol *MBBSym = MBB->getSymbol(); 1097 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1098 return; 1099 } 1100 1101 case MachineJumpTableInfo::EK_LabelDifference32: { 1102 // EK_LabelDifference32 - Each entry is the address of the block minus 1103 // the address of the jump table. This is used for PIC jump tables where 1104 // gprel32 is not supported. e.g.: 1105 // .word LBB123 - LJTI1_2 1106 // If the .set directive is supported, this is emitted as: 1107 // .set L4_5_set_123, LBB123 - LJTI1_2 1108 // .word L4_5_set_123 1109 1110 // If we have emitted set directives for the jump table entries, print 1111 // them rather than the entries themselves. If we're emitting PIC, then 1112 // emit the table entries as differences between two text section labels. 1113 if (MAI->hasSetDirective()) { 1114 // If we used .set, reference the .set's symbol. 1115 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1116 OutContext); 1117 break; 1118 } 1119 // Otherwise, use the difference as the jump table entry. 1120 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1121 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1122 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1123 break; 1124 } 1125 } 1126 1127 assert(Value && "Unknown entry kind!"); 1128 1129 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1130 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1131} 1132 1133 1134/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1135/// special global used by LLVM. If so, emit it and return true, otherwise 1136/// do nothing and return false. 1137bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1138 if (GV->getName() == "llvm.used") { 1139 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1140 EmitLLVMUsedList(GV->getInitializer()); 1141 return true; 1142 } 1143 1144 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1145 if (GV->getSection() == "llvm.metadata" || 1146 GV->hasAvailableExternallyLinkage()) 1147 return true; 1148 1149 if (!GV->hasAppendingLinkage()) return false; 1150 1151 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1152 1153 const TargetData *TD = TM.getTargetData(); 1154 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1155 if (GV->getName() == "llvm.global_ctors") { 1156 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1157 EmitAlignment(Align); 1158 EmitXXStructorList(GV->getInitializer()); 1159 1160 if (TM.getRelocationModel() == Reloc::Static && 1161 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1162 StringRef Sym(".constructors_used"); 1163 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1164 MCSA_Reference); 1165 } 1166 return true; 1167 } 1168 1169 if (GV->getName() == "llvm.global_dtors") { 1170 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1171 EmitAlignment(Align); 1172 EmitXXStructorList(GV->getInitializer()); 1173 1174 if (TM.getRelocationModel() == Reloc::Static && 1175 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1176 StringRef Sym(".destructors_used"); 1177 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1178 MCSA_Reference); 1179 } 1180 return true; 1181 } 1182 1183 return false; 1184} 1185 1186/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1187/// global in the specified llvm.used list for which emitUsedDirectiveFor 1188/// is true, as being used with this directive. 1189void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1190 // Should be an array of 'i8*'. 1191 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1192 if (InitList == 0) return; 1193 1194 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1195 const GlobalValue *GV = 1196 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1197 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1198 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1199 } 1200} 1201 1202/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1203/// function pointers, ignoring the init priority. 1204void AsmPrinter::EmitXXStructorList(Constant *List) { 1205 // Should be an array of '{ int, void ()* }' structs. The first value is the 1206 // init priority, which we ignore. 1207 if (!isa<ConstantArray>(List)) return; 1208 ConstantArray *InitList = cast<ConstantArray>(List); 1209 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1210 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1211 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1212 1213 if (CS->getOperand(1)->isNullValue()) 1214 return; // Found a null terminator, exit printing. 1215 // Emit the function pointer. 1216 EmitGlobalConstant(CS->getOperand(1)); 1217 } 1218} 1219 1220//===--------------------------------------------------------------------===// 1221// Emission and print routines 1222// 1223 1224/// EmitInt8 - Emit a byte directive and value. 1225/// 1226void AsmPrinter::EmitInt8(int Value) const { 1227 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1228} 1229 1230/// EmitInt16 - Emit a short directive and value. 1231/// 1232void AsmPrinter::EmitInt16(int Value) const { 1233 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1234} 1235 1236/// EmitInt32 - Emit a long directive and value. 1237/// 1238void AsmPrinter::EmitInt32(int Value) const { 1239 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1240} 1241 1242/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1243/// in bytes of the directive is specified by Size and Hi/Lo specify the 1244/// labels. This implicitly uses .set if it is available. 1245void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1246 unsigned Size) const { 1247 // Get the Hi-Lo expression. 1248 const MCExpr *Diff = 1249 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1250 MCSymbolRefExpr::Create(Lo, OutContext), 1251 OutContext); 1252 1253 if (!MAI->hasSetDirective()) { 1254 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1255 return; 1256 } 1257 1258 // Otherwise, emit with .set (aka assignment). 1259 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1260 OutStreamer.EmitAssignment(SetLabel, Diff); 1261 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1262} 1263 1264/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1265/// where the size in bytes of the directive is specified by Size and Hi/Lo 1266/// specify the labels. This implicitly uses .set if it is available. 1267void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1268 const MCSymbol *Lo, unsigned Size) 1269 const { 1270 1271 // Emit Hi+Offset - Lo 1272 // Get the Hi+Offset expression. 1273 const MCExpr *Plus = 1274 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1275 MCConstantExpr::Create(Offset, OutContext), 1276 OutContext); 1277 1278 // Get the Hi+Offset-Lo expression. 1279 const MCExpr *Diff = 1280 MCBinaryExpr::CreateSub(Plus, 1281 MCSymbolRefExpr::Create(Lo, OutContext), 1282 OutContext); 1283 1284 if (!MAI->hasSetDirective()) 1285 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1286 else { 1287 // Otherwise, emit with .set (aka assignment). 1288 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1289 OutStreamer.EmitAssignment(SetLabel, Diff); 1290 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1291 } 1292} 1293 1294/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1295/// where the size in bytes of the directive is specified by Size and Label 1296/// specifies the label. This implicitly uses .set if it is available. 1297void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1298 unsigned Size) 1299 const { 1300 1301 // Emit Label+Offset 1302 const MCExpr *Plus = 1303 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1304 MCConstantExpr::Create(Offset, OutContext), 1305 OutContext); 1306 1307 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1308} 1309 1310 1311//===----------------------------------------------------------------------===// 1312 1313// EmitAlignment - Emit an alignment directive to the specified power of 1314// two boundary. For example, if you pass in 3 here, you will get an 8 1315// byte alignment. If a global value is specified, and if that global has 1316// an explicit alignment requested, it will override the alignment request 1317// if required for correctness. 1318// 1319void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1320 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1321 1322 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1323 1324 if (getCurrentSection()->getKind().isText()) 1325 OutStreamer.EmitCodeAlignment(1 << NumBits); 1326 else 1327 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1328} 1329 1330//===----------------------------------------------------------------------===// 1331// Constant emission. 1332//===----------------------------------------------------------------------===// 1333 1334/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1335/// 1336static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1337 MCContext &Ctx = AP.OutContext; 1338 1339 if (CV->isNullValue() || isa<UndefValue>(CV)) 1340 return MCConstantExpr::Create(0, Ctx); 1341 1342 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1343 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1344 1345 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1346 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1347 1348 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1349 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1350 1351 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1352 if (CE == 0) { 1353 llvm_unreachable("Unknown constant value to lower!"); 1354 return MCConstantExpr::Create(0, Ctx); 1355 } 1356 1357 switch (CE->getOpcode()) { 1358 default: 1359 // If the code isn't optimized, there may be outstanding folding 1360 // opportunities. Attempt to fold the expression using TargetData as a 1361 // last resort before giving up. 1362 if (Constant *C = 1363 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1364 if (C != CE) 1365 return LowerConstant(C, AP); 1366 1367 // Otherwise report the problem to the user. 1368 { 1369 std::string S; 1370 raw_string_ostream OS(S); 1371 OS << "Unsupported expression in static initializer: "; 1372 WriteAsOperand(OS, CE, /*PrintType=*/false, 1373 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1374 report_fatal_error(OS.str()); 1375 } 1376 return MCConstantExpr::Create(0, Ctx); 1377 case Instruction::GetElementPtr: { 1378 const TargetData &TD = *AP.TM.getTargetData(); 1379 // Generate a symbolic expression for the byte address 1380 const Constant *PtrVal = CE->getOperand(0); 1381 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1382 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1383 IdxVec.size()); 1384 1385 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1386 if (Offset == 0) 1387 return Base; 1388 1389 // Truncate/sext the offset to the pointer size. 1390 if (TD.getPointerSizeInBits() != 64) { 1391 int SExtAmount = 64-TD.getPointerSizeInBits(); 1392 Offset = (Offset << SExtAmount) >> SExtAmount; 1393 } 1394 1395 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1396 Ctx); 1397 } 1398 1399 case Instruction::Trunc: 1400 // We emit the value and depend on the assembler to truncate the generated 1401 // expression properly. This is important for differences between 1402 // blockaddress labels. Since the two labels are in the same function, it 1403 // is reasonable to treat their delta as a 32-bit value. 1404 // FALL THROUGH. 1405 case Instruction::BitCast: 1406 return LowerConstant(CE->getOperand(0), AP); 1407 1408 case Instruction::IntToPtr: { 1409 const TargetData &TD = *AP.TM.getTargetData(); 1410 // Handle casts to pointers by changing them into casts to the appropriate 1411 // integer type. This promotes constant folding and simplifies this code. 1412 Constant *Op = CE->getOperand(0); 1413 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1414 false/*ZExt*/); 1415 return LowerConstant(Op, AP); 1416 } 1417 1418 case Instruction::PtrToInt: { 1419 const TargetData &TD = *AP.TM.getTargetData(); 1420 // Support only foldable casts to/from pointers that can be eliminated by 1421 // changing the pointer to the appropriately sized integer type. 1422 Constant *Op = CE->getOperand(0); 1423 const Type *Ty = CE->getType(); 1424 1425 const MCExpr *OpExpr = LowerConstant(Op, AP); 1426 1427 // We can emit the pointer value into this slot if the slot is an 1428 // integer slot equal to the size of the pointer. 1429 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1430 return OpExpr; 1431 1432 // Otherwise the pointer is smaller than the resultant integer, mask off 1433 // the high bits so we are sure to get a proper truncation if the input is 1434 // a constant expr. 1435 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1436 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1437 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1438 } 1439 1440 // The MC library also has a right-shift operator, but it isn't consistently 1441 // signed or unsigned between different targets. 1442 case Instruction::Add: 1443 case Instruction::Sub: 1444 case Instruction::Mul: 1445 case Instruction::SDiv: 1446 case Instruction::SRem: 1447 case Instruction::Shl: 1448 case Instruction::And: 1449 case Instruction::Or: 1450 case Instruction::Xor: { 1451 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1452 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1453 switch (CE->getOpcode()) { 1454 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1455 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1456 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1457 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1458 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1459 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1460 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1461 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1462 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1463 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1464 } 1465 } 1466 } 1467} 1468 1469static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1470 AsmPrinter &AP); 1471 1472static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1473 AsmPrinter &AP) { 1474 if (AddrSpace != 0 || !CA->isString()) { 1475 // Not a string. Print the values in successive locations 1476 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1477 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1478 return; 1479 } 1480 1481 // Otherwise, it can be emitted as .ascii. 1482 SmallVector<char, 128> TmpVec; 1483 TmpVec.reserve(CA->getNumOperands()); 1484 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1485 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1486 1487 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1488} 1489 1490static void EmitGlobalConstantVector(const ConstantVector *CV, 1491 unsigned AddrSpace, AsmPrinter &AP) { 1492 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1493 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1494} 1495 1496static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1497 unsigned AddrSpace, AsmPrinter &AP) { 1498 // Print the fields in successive locations. Pad to align if needed! 1499 const TargetData *TD = AP.TM.getTargetData(); 1500 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1501 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1502 uint64_t SizeSoFar = 0; 1503 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1504 const Constant *Field = CS->getOperand(i); 1505 1506 // Check if padding is needed and insert one or more 0s. 1507 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1508 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1509 - Layout->getElementOffset(i)) - FieldSize; 1510 SizeSoFar += FieldSize + PadSize; 1511 1512 // Now print the actual field value. 1513 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1514 1515 // Insert padding - this may include padding to increase the size of the 1516 // current field up to the ABI size (if the struct is not packed) as well 1517 // as padding to ensure that the next field starts at the right offset. 1518 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1519 } 1520 assert(SizeSoFar == Layout->getSizeInBytes() && 1521 "Layout of constant struct may be incorrect!"); 1522} 1523 1524static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1525 AsmPrinter &AP) { 1526 // FP Constants are printed as integer constants to avoid losing 1527 // precision. 1528 if (CFP->getType()->isDoubleTy()) { 1529 if (AP.isVerbose()) { 1530 double Val = CFP->getValueAPF().convertToDouble(); 1531 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1532 } 1533 1534 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1535 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1536 return; 1537 } 1538 1539 if (CFP->getType()->isFloatTy()) { 1540 if (AP.isVerbose()) { 1541 float Val = CFP->getValueAPF().convertToFloat(); 1542 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1543 } 1544 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1545 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1546 return; 1547 } 1548 1549 if (CFP->getType()->isX86_FP80Ty()) { 1550 // all long double variants are printed as hex 1551 // API needed to prevent premature destruction 1552 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1553 const uint64_t *p = API.getRawData(); 1554 if (AP.isVerbose()) { 1555 // Convert to double so we can print the approximate val as a comment. 1556 APFloat DoubleVal = CFP->getValueAPF(); 1557 bool ignored; 1558 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1559 &ignored); 1560 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1561 << DoubleVal.convertToDouble() << '\n'; 1562 } 1563 1564 if (AP.TM.getTargetData()->isBigEndian()) { 1565 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1566 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1567 } else { 1568 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1569 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1570 } 1571 1572 // Emit the tail padding for the long double. 1573 const TargetData &TD = *AP.TM.getTargetData(); 1574 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1575 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1576 return; 1577 } 1578 1579 assert(CFP->getType()->isPPC_FP128Ty() && 1580 "Floating point constant type not handled"); 1581 // All long double variants are printed as hex 1582 // API needed to prevent premature destruction. 1583 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1584 const uint64_t *p = API.getRawData(); 1585 if (AP.TM.getTargetData()->isBigEndian()) { 1586 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1587 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1588 } else { 1589 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1590 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1591 } 1592} 1593 1594static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1595 unsigned AddrSpace, AsmPrinter &AP) { 1596 const TargetData *TD = AP.TM.getTargetData(); 1597 unsigned BitWidth = CI->getBitWidth(); 1598 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1599 1600 // We don't expect assemblers to support integer data directives 1601 // for more than 64 bits, so we emit the data in at most 64-bit 1602 // quantities at a time. 1603 const uint64_t *RawData = CI->getValue().getRawData(); 1604 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1605 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1606 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1607 } 1608} 1609 1610static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1611 AsmPrinter &AP) { 1612 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1613 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1614 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1615 } 1616 1617 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1618 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1619 switch (Size) { 1620 case 1: 1621 case 2: 1622 case 4: 1623 case 8: 1624 if (AP.isVerbose()) 1625 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1626 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1627 return; 1628 default: 1629 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1630 return; 1631 } 1632 } 1633 1634 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1635 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1636 1637 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1638 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1639 1640 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1641 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1642 1643 if (isa<ConstantPointerNull>(CV)) { 1644 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1645 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1646 return; 1647 } 1648 1649 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1650 return EmitGlobalConstantVector(V, AddrSpace, AP); 1651 1652 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1653 // thread the streamer with EmitValue. 1654 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1655 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1656 AddrSpace); 1657} 1658 1659/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1660void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1661 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1662 if (Size) 1663 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1664 else if (MAI->hasSubsectionsViaSymbols()) { 1665 // If the global has zero size, emit a single byte so that two labels don't 1666 // look like they are at the same location. 1667 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1668 } 1669} 1670 1671void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1672 // Target doesn't support this yet! 1673 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1674} 1675 1676void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1677 if (Offset > 0) 1678 OS << '+' << Offset; 1679 else if (Offset < 0) 1680 OS << Offset; 1681} 1682 1683//===----------------------------------------------------------------------===// 1684// Symbol Lowering Routines. 1685//===----------------------------------------------------------------------===// 1686 1687/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1688/// temporary label with the specified stem and unique ID. 1689MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1690 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1691 Name + Twine(ID)); 1692} 1693 1694/// GetTempSymbol - Return an assembler temporary label with the specified 1695/// stem. 1696MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1697 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1698 Name); 1699} 1700 1701 1702MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1703 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1704} 1705 1706MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1707 return MMI->getAddrLabelSymbol(BB); 1708} 1709 1710/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1711MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1712 return OutContext.GetOrCreateSymbol 1713 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1714 + "_" + Twine(CPID)); 1715} 1716 1717/// GetJTISymbol - Return the symbol for the specified jump table entry. 1718MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1719 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1720} 1721 1722/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1723/// FIXME: privatize to AsmPrinter. 1724MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1725 return OutContext.GetOrCreateSymbol 1726 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1727 Twine(UID) + "_set_" + Twine(MBBID)); 1728} 1729 1730/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1731/// global value name as its base, with the specified suffix, and where the 1732/// symbol is forced to have private linkage if ForcePrivate is true. 1733MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1734 StringRef Suffix, 1735 bool ForcePrivate) const { 1736 SmallString<60> NameStr; 1737 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1738 NameStr.append(Suffix.begin(), Suffix.end()); 1739 return OutContext.GetOrCreateSymbol(NameStr.str()); 1740} 1741 1742/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1743/// ExternalSymbol. 1744MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1745 SmallString<60> NameStr; 1746 Mang->getNameWithPrefix(NameStr, Sym); 1747 return OutContext.GetOrCreateSymbol(NameStr.str()); 1748} 1749 1750 1751 1752/// PrintParentLoopComment - Print comments about parent loops of this one. 1753static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1754 unsigned FunctionNumber) { 1755 if (Loop == 0) return; 1756 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1757 OS.indent(Loop->getLoopDepth()*2) 1758 << "Parent Loop BB" << FunctionNumber << "_" 1759 << Loop->getHeader()->getNumber() 1760 << " Depth=" << Loop->getLoopDepth() << '\n'; 1761} 1762 1763 1764/// PrintChildLoopComment - Print comments about child loops within 1765/// the loop for this basic block, with nesting. 1766static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1767 unsigned FunctionNumber) { 1768 // Add child loop information 1769 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1770 OS.indent((*CL)->getLoopDepth()*2) 1771 << "Child Loop BB" << FunctionNumber << "_" 1772 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1773 << '\n'; 1774 PrintChildLoopComment(OS, *CL, FunctionNumber); 1775 } 1776} 1777 1778/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1779static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1780 const MachineLoopInfo *LI, 1781 const AsmPrinter &AP) { 1782 // Add loop depth information 1783 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1784 if (Loop == 0) return; 1785 1786 MachineBasicBlock *Header = Loop->getHeader(); 1787 assert(Header && "No header for loop"); 1788 1789 // If this block is not a loop header, just print out what is the loop header 1790 // and return. 1791 if (Header != &MBB) { 1792 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1793 Twine(AP.getFunctionNumber())+"_" + 1794 Twine(Loop->getHeader()->getNumber())+ 1795 " Depth="+Twine(Loop->getLoopDepth())); 1796 return; 1797 } 1798 1799 // Otherwise, it is a loop header. Print out information about child and 1800 // parent loops. 1801 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1802 1803 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1804 1805 OS << "=>"; 1806 OS.indent(Loop->getLoopDepth()*2-2); 1807 1808 OS << "This "; 1809 if (Loop->empty()) 1810 OS << "Inner "; 1811 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1812 1813 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1814} 1815 1816 1817/// EmitBasicBlockStart - This method prints the label for the specified 1818/// MachineBasicBlock, an alignment (if present) and a comment describing 1819/// it if appropriate. 1820void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1821 // Emit an alignment directive for this block, if needed. 1822 if (unsigned Align = MBB->getAlignment()) 1823 EmitAlignment(Log2_32(Align)); 1824 1825 // If the block has its address taken, emit any labels that were used to 1826 // reference the block. It is possible that there is more than one label 1827 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1828 // the references were generated. 1829 if (MBB->hasAddressTaken()) { 1830 const BasicBlock *BB = MBB->getBasicBlock(); 1831 if (isVerbose()) 1832 OutStreamer.AddComment("Block address taken"); 1833 1834 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1835 1836 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1837 OutStreamer.EmitLabel(Syms[i]); 1838 } 1839 1840 // Print the main label for the block. 1841 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1842 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1843 if (const BasicBlock *BB = MBB->getBasicBlock()) 1844 if (BB->hasName()) 1845 OutStreamer.AddComment("%" + BB->getName()); 1846 1847 EmitBasicBlockLoopComments(*MBB, LI, *this); 1848 1849 // NOTE: Want this comment at start of line, don't emit with AddComment. 1850 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1851 Twine(MBB->getNumber()) + ":"); 1852 } 1853 } else { 1854 if (isVerbose()) { 1855 if (const BasicBlock *BB = MBB->getBasicBlock()) 1856 if (BB->hasName()) 1857 OutStreamer.AddComment("%" + BB->getName()); 1858 EmitBasicBlockLoopComments(*MBB, LI, *this); 1859 } 1860 1861 OutStreamer.EmitLabel(MBB->getSymbol()); 1862 } 1863} 1864 1865void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility, 1866 bool IsDefinition) const { 1867 MCSymbolAttr Attr = MCSA_Invalid; 1868 1869 switch (Visibility) { 1870 default: break; 1871 case GlobalValue::HiddenVisibility: 1872 if (IsDefinition) 1873 Attr = MAI->getHiddenVisibilityAttr(); 1874 else 1875 Attr = MAI->getHiddenDeclarationVisibilityAttr(); 1876 break; 1877 case GlobalValue::ProtectedVisibility: 1878 Attr = MAI->getProtectedVisibilityAttr(); 1879 break; 1880 } 1881 1882 if (Attr != MCSA_Invalid) 1883 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1884} 1885 1886/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1887/// exactly one predecessor and the control transfer mechanism between 1888/// the predecessor and this block is a fall-through. 1889bool AsmPrinter:: 1890isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1891 // If this is a landing pad, it isn't a fall through. If it has no preds, 1892 // then nothing falls through to it. 1893 if (MBB->isLandingPad() || MBB->pred_empty()) 1894 return false; 1895 1896 // If there isn't exactly one predecessor, it can't be a fall through. 1897 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1898 ++PI2; 1899 if (PI2 != MBB->pred_end()) 1900 return false; 1901 1902 // The predecessor has to be immediately before this block. 1903 const MachineBasicBlock *Pred = *PI; 1904 1905 if (!Pred->isLayoutSuccessor(MBB)) 1906 return false; 1907 1908 // If the block is completely empty, then it definitely does fall through. 1909 if (Pred->empty()) 1910 return true; 1911 1912 // Otherwise, check the last instruction. 1913 const MachineInstr &LastInst = Pred->back(); 1914 return !LastInst.getDesc().isBarrier(); 1915} 1916 1917 1918 1919GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1920 if (!S->usesMetadata()) 1921 return 0; 1922 1923 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1924 gcp_map_type::iterator GCPI = GCMap.find(S); 1925 if (GCPI != GCMap.end()) 1926 return GCPI->second; 1927 1928 const char *Name = S->getName().c_str(); 1929 1930 for (GCMetadataPrinterRegistry::iterator 1931 I = GCMetadataPrinterRegistry::begin(), 1932 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1933 if (strcmp(Name, I->getName()) == 0) { 1934 GCMetadataPrinter *GMP = I->instantiate(); 1935 GMP->S = S; 1936 GCMap.insert(std::make_pair(S, GMP)); 1937 return GMP; 1938 } 1939 1940 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1941 return 0; 1942} 1943 1944