AsmPrinter.cpp revision 3965b5e974d57f3e56a2c7f37d76d73e572dfb20
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file implements the AsmPrinter class. 11// 12//===----------------------------------------------------------------------===// 13 14#define DEBUG_TYPE "asm-printer" 15#include "llvm/CodeGen/AsmPrinter.h" 16#include "DwarfDebug.h" 17#include "DwarfException.h" 18#include "llvm/Module.h" 19#include "llvm/CodeGen/GCMetadataPrinter.h" 20#include "llvm/CodeGen/MachineConstantPool.h" 21#include "llvm/CodeGen/MachineFrameInfo.h" 22#include "llvm/CodeGen/MachineFunction.h" 23#include "llvm/CodeGen/MachineJumpTableInfo.h" 24#include "llvm/CodeGen/MachineLoopInfo.h" 25#include "llvm/CodeGen/MachineModuleInfo.h" 26#include "llvm/Analysis/ConstantFolding.h" 27#include "llvm/Analysis/DebugInfo.h" 28#include "llvm/MC/MCAsmInfo.h" 29#include "llvm/MC/MCContext.h" 30#include "llvm/MC/MCExpr.h" 31#include "llvm/MC/MCInst.h" 32#include "llvm/MC/MCSection.h" 33#include "llvm/MC/MCStreamer.h" 34#include "llvm/MC/MCSymbol.h" 35#include "llvm/Target/Mangler.h" 36#include "llvm/Target/TargetData.h" 37#include "llvm/Target/TargetInstrInfo.h" 38#include "llvm/Target/TargetLowering.h" 39#include "llvm/Target/TargetLoweringObjectFile.h" 40#include "llvm/Target/TargetRegisterInfo.h" 41#include "llvm/Assembly/Writer.h" 42#include "llvm/ADT/SmallString.h" 43#include "llvm/ADT/Statistic.h" 44#include "llvm/Support/ErrorHandling.h" 45#include "llvm/Support/Format.h" 46#include "llvm/Support/Timer.h" 47using namespace llvm; 48 49static const char *DWARFGroupName = "DWARF Emission"; 50static const char *DbgTimerName = "DWARF Debug Writer"; 51static const char *EHTimerName = "DWARF Exception Writer"; 52 53STATISTIC(EmittedInsts, "Number of machine instrs printed"); 54 55char AsmPrinter::ID = 0; 56 57typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type; 58static gcp_map_type &getGCMap(void *&P) { 59 if (P == 0) 60 P = new gcp_map_type(); 61 return *(gcp_map_type*)P; 62} 63 64 65/// getGVAlignmentLog2 - Return the alignment to use for the specified global 66/// value in log2 form. This rounds up to the preferred alignment if possible 67/// and legal. 68static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD, 69 unsigned InBits = 0) { 70 unsigned NumBits = 0; 71 if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV)) 72 NumBits = TD.getPreferredAlignmentLog(GVar); 73 74 // If InBits is specified, round it to it. 75 if (InBits > NumBits) 76 NumBits = InBits; 77 78 // If the GV has a specified alignment, take it into account. 79 if (GV->getAlignment() == 0) 80 return NumBits; 81 82 unsigned GVAlign = Log2_32(GV->getAlignment()); 83 84 // If the GVAlign is larger than NumBits, or if we are required to obey 85 // NumBits because the GV has an assigned section, obey it. 86 if (GVAlign > NumBits || GV->hasSection()) 87 NumBits = GVAlign; 88 return NumBits; 89} 90 91 92 93 94AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer) 95 : MachineFunctionPass(ID), 96 TM(tm), MAI(tm.getMCAsmInfo()), 97 OutContext(Streamer.getContext()), 98 OutStreamer(Streamer), 99 LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) { 100 DD = 0; DE = 0; MMI = 0; LI = 0; 101 GCMetadataPrinters = 0; 102 VerboseAsm = Streamer.isVerboseAsm(); 103} 104 105AsmPrinter::~AsmPrinter() { 106 assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized"); 107 108 if (GCMetadataPrinters != 0) { 109 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 110 111 for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I) 112 delete I->second; 113 delete &GCMap; 114 GCMetadataPrinters = 0; 115 } 116 117 delete &OutStreamer; 118} 119 120/// getFunctionNumber - Return a unique ID for the current function. 121/// 122unsigned AsmPrinter::getFunctionNumber() const { 123 return MF->getFunctionNumber(); 124} 125 126const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const { 127 return TM.getTargetLowering()->getObjFileLowering(); 128} 129 130 131/// getTargetData - Return information about data layout. 132const TargetData &AsmPrinter::getTargetData() const { 133 return *TM.getTargetData(); 134} 135 136/// getCurrentSection() - Return the current section we are emitting to. 137const MCSection *AsmPrinter::getCurrentSection() const { 138 return OutStreamer.getCurrentSection(); 139} 140 141 142 143void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const { 144 AU.setPreservesAll(); 145 MachineFunctionPass::getAnalysisUsage(AU); 146 AU.addRequired<MachineModuleInfo>(); 147 AU.addRequired<GCModuleInfo>(); 148 if (isVerbose()) 149 AU.addRequired<MachineLoopInfo>(); 150} 151 152bool AsmPrinter::doInitialization(Module &M) { 153 MMI = getAnalysisIfAvailable<MachineModuleInfo>(); 154 MMI->AnalyzeModule(M); 155 156 // Initialize TargetLoweringObjectFile. 157 const_cast<TargetLoweringObjectFile&>(getObjFileLowering()) 158 .Initialize(OutContext, TM); 159 160 Mang = new Mangler(OutContext, *TM.getTargetData()); 161 162 // Allow the target to emit any magic that it wants at the start of the file. 163 EmitStartOfAsmFile(M); 164 165 // Very minimal debug info. It is ignored if we emit actual debug info. If we 166 // don't, this at least helps the user find where a global came from. 167 if (MAI->hasSingleParameterDotFile()) { 168 // .file "foo.c" 169 OutStreamer.EmitFileDirective(M.getModuleIdentifier()); 170 } 171 172 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 173 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 174 for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I) 175 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I)) 176 MP->beginAssembly(*this); 177 178 // Emit module-level inline asm if it exists. 179 if (!M.getModuleInlineAsm().empty()) { 180 OutStreamer.AddComment("Start of file scope inline assembly"); 181 OutStreamer.AddBlankLine(); 182 EmitInlineAsm(M.getModuleInlineAsm()+"\n"); 183 OutStreamer.AddComment("End of file scope inline assembly"); 184 OutStreamer.AddBlankLine(); 185 } 186 187 if (MAI->doesSupportDebugInformation()) 188 DD = new DwarfDebug(this, &M); 189 190 if (MAI->doesSupportExceptionHandling()) 191 switch (MAI->getExceptionHandlingType()) { 192 default: 193 case ExceptionHandling::DwarfTable: 194 DE = new DwarfTableException(this); 195 break; 196 case ExceptionHandling::DwarfCFI: 197 DE = new DwarfCFIException(this); 198 break; 199 } 200 201 return false; 202} 203 204void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 205 switch ((GlobalValue::LinkageTypes)Linkage) { 206 case GlobalValue::CommonLinkage: 207 case GlobalValue::LinkOnceAnyLinkage: 208 case GlobalValue::LinkOnceODRLinkage: 209 case GlobalValue::WeakAnyLinkage: 210 case GlobalValue::WeakODRLinkage: 211 case GlobalValue::LinkerPrivateWeakLinkage: 212 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 213 if (MAI->getWeakDefDirective() != 0) { 214 // .globl _foo 215 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 216 217 if ((GlobalValue::LinkageTypes)Linkage != 218 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 219 // .weak_definition _foo 220 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 221 else 222 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 223 } else if (MAI->getLinkOnceDirective() != 0) { 224 // .globl _foo 225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 226 //NOTE: linkonce is handled by the section the symbol was assigned to. 227 } else { 228 // .weak _foo 229 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 230 } 231 break; 232 case GlobalValue::DLLExportLinkage: 233 case GlobalValue::AppendingLinkage: 234 // FIXME: appending linkage variables should go into a section of 235 // their name or something. For now, just emit them as external. 236 case GlobalValue::ExternalLinkage: 237 // If external or appending, declare as a global symbol. 238 // .globl _foo 239 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 240 break; 241 case GlobalValue::PrivateLinkage: 242 case GlobalValue::InternalLinkage: 243 case GlobalValue::LinkerPrivateLinkage: 244 break; 245 default: 246 llvm_unreachable("Unknown linkage type!"); 247 } 248} 249 250 251/// EmitGlobalVariable - Emit the specified global variable to the .s file. 252void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 253 if (!GV->hasInitializer()) // External globals require no code. 254 return; 255 256 // Check to see if this is a special global used by LLVM, if so, emit it. 257 if (EmitSpecialLLVMGlobal(GV)) 258 return; 259 260 if (isVerbose()) { 261 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 262 /*PrintType=*/false, GV->getParent()); 263 OutStreamer.GetCommentOS() << '\n'; 264 } 265 266 MCSymbol *GVSym = Mang->getSymbol(GV); 267 EmitVisibility(GVSym, GV->getVisibility()); 268 269 if (MAI->hasDotTypeDotSizeDirective()) 270 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 271 272 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 273 274 const TargetData *TD = TM.getTargetData(); 275 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 276 277 // If the alignment is specified, we *must* obey it. Overaligning a global 278 // with a specified alignment is a prompt way to break globals emitted to 279 // sections and expected to be contiguous (e.g. ObjC metadata). 280 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 281 282 // Handle common and BSS local symbols (.lcomm). 283 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 284 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 285 286 if (isVerbose()) { 287 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 288 /*PrintType=*/false, GV->getParent()); 289 OutStreamer.GetCommentOS() << '\n'; 290 } 291 292 // Handle common symbols. 293 if (GVKind.isCommon()) { 294 unsigned Align = 1 << AlignLog; 295 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 296 Align = 0; 297 298 // .comm _foo, 42, 4 299 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 300 return; 301 } 302 303 // Handle local BSS symbols. 304 if (MAI->hasMachoZeroFillDirective()) { 305 const MCSection *TheSection = 306 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 307 // .zerofill __DATA, __bss, _foo, 400, 5 308 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 309 return; 310 } 311 312 if (MAI->hasLCOMMDirective()) { 313 // .lcomm _foo, 42 314 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 315 return; 316 } 317 318 unsigned Align = 1 << AlignLog; 319 if (!getObjFileLowering().getCommDirectiveSupportsAlignment()) 320 Align = 0; 321 322 // .local _foo 323 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 324 // .comm _foo, 42, 4 325 OutStreamer.EmitCommonSymbol(GVSym, Size, Align); 326 return; 327 } 328 329 const MCSection *TheSection = 330 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 331 332 // Handle the zerofill directive on darwin, which is a special form of BSS 333 // emission. 334 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 335 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 336 337 // .globl _foo 338 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 339 // .zerofill __DATA, __common, _foo, 400, 5 340 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 341 return; 342 } 343 344 // Handle thread local data for mach-o which requires us to output an 345 // additional structure of data and mangle the original symbol so that we 346 // can reference it later. 347 // 348 // TODO: This should become an "emit thread local global" method on TLOF. 349 // All of this macho specific stuff should be sunk down into TLOFMachO and 350 // stuff like "TLSExtraDataSection" should no longer be part of the parent 351 // TLOF class. This will also make it more obvious that stuff like 352 // MCStreamer::EmitTBSSSymbol is macho specific and only called from macho 353 // specific code. 354 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 355 // Emit the .tbss symbol 356 MCSymbol *MangSym = 357 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 358 359 if (GVKind.isThreadBSS()) 360 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 361 else if (GVKind.isThreadData()) { 362 OutStreamer.SwitchSection(TheSection); 363 364 EmitAlignment(AlignLog, GV); 365 OutStreamer.EmitLabel(MangSym); 366 367 EmitGlobalConstant(GV->getInitializer()); 368 } 369 370 OutStreamer.AddBlankLine(); 371 372 // Emit the variable struct for the runtime. 373 const MCSection *TLVSect 374 = getObjFileLowering().getTLSExtraDataSection(); 375 376 OutStreamer.SwitchSection(TLVSect); 377 // Emit the linkage here. 378 EmitLinkage(GV->getLinkage(), GVSym); 379 OutStreamer.EmitLabel(GVSym); 380 381 // Three pointers in size: 382 // - __tlv_bootstrap - used to make sure support exists 383 // - spare pointer, used when mapped by the runtime 384 // - pointer to mangled symbol above with initializer 385 unsigned PtrSize = TD->getPointerSizeInBits()/8; 386 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 387 PtrSize, 0); 388 OutStreamer.EmitIntValue(0, PtrSize, 0); 389 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 390 391 OutStreamer.AddBlankLine(); 392 return; 393 } 394 395 OutStreamer.SwitchSection(TheSection); 396 397 EmitLinkage(GV->getLinkage(), GVSym); 398 EmitAlignment(AlignLog, GV); 399 400 OutStreamer.EmitLabel(GVSym); 401 402 EmitGlobalConstant(GV->getInitializer()); 403 404 if (MAI->hasDotTypeDotSizeDirective()) 405 // .size foo, 42 406 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 407 408 OutStreamer.AddBlankLine(); 409} 410 411/// EmitFunctionHeader - This method emits the header for the current 412/// function. 413void AsmPrinter::EmitFunctionHeader() { 414 // Print out constants referenced by the function 415 EmitConstantPool(); 416 417 // Print the 'header' of function. 418 const Function *F = MF->getFunction(); 419 420 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 421 EmitVisibility(CurrentFnSym, F->getVisibility()); 422 423 EmitLinkage(F->getLinkage(), CurrentFnSym); 424 EmitAlignment(MF->getAlignment(), F); 425 426 if (MAI->hasDotTypeDotSizeDirective()) 427 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 428 429 if (isVerbose()) { 430 WriteAsOperand(OutStreamer.GetCommentOS(), F, 431 /*PrintType=*/false, F->getParent()); 432 OutStreamer.GetCommentOS() << '\n'; 433 } 434 435 // Emit the CurrentFnSym. This is a virtual function to allow targets to 436 // do their wild and crazy things as required. 437 EmitFunctionEntryLabel(); 438 439 // If the function had address-taken blocks that got deleted, then we have 440 // references to the dangling symbols. Emit them at the start of the function 441 // so that we don't get references to undefined symbols. 442 std::vector<MCSymbol*> DeadBlockSyms; 443 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 444 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 445 OutStreamer.AddComment("Address taken block that was later removed"); 446 OutStreamer.EmitLabel(DeadBlockSyms[i]); 447 } 448 449 // Add some workaround for linkonce linkage on Cygwin\MinGW. 450 if (MAI->getLinkOnceDirective() != 0 && 451 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 452 // FIXME: What is this? 453 MCSymbol *FakeStub = 454 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 455 CurrentFnSym->getName()); 456 OutStreamer.EmitLabel(FakeStub); 457 } 458 459 // Emit pre-function debug and/or EH information. 460 if (DE) { 461 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 462 DE->BeginFunction(MF); 463 } 464 if (DD) { 465 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 466 DD->beginFunction(MF); 467 } 468} 469 470/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 471/// function. This can be overridden by targets as required to do custom stuff. 472void AsmPrinter::EmitFunctionEntryLabel() { 473 // The function label could have already been emitted if two symbols end up 474 // conflicting due to asm renaming. Detect this and emit an error. 475 if (CurrentFnSym->isUndefined()) 476 return OutStreamer.EmitLabel(CurrentFnSym); 477 478 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 479 "' label emitted multiple times to assembly file"); 480} 481 482 483static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF, 484 raw_ostream &CommentOS) { 485 const LLVMContext &Ctx = MF->getFunction()->getContext(); 486 if (!DL.isUnknown()) { // Print source line info. 487 DIScope Scope(DL.getScope(Ctx)); 488 // Omit the directory, because it's likely to be long and uninteresting. 489 if (Scope.Verify()) 490 CommentOS << Scope.getFilename(); 491 else 492 CommentOS << "<unknown>"; 493 CommentOS << ':' << DL.getLine(); 494 if (DL.getCol() != 0) 495 CommentOS << ':' << DL.getCol(); 496 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx)); 497 if (!InlinedAtDL.isUnknown()) { 498 CommentOS << "[ "; 499 EmitDebugLoc(InlinedAtDL, MF, CommentOS); 500 CommentOS << " ]"; 501 } 502 } 503} 504 505/// EmitComments - Pretty-print comments for instructions. 506static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 507 const MachineFunction *MF = MI.getParent()->getParent(); 508 const TargetMachine &TM = MF->getTarget(); 509 510 DebugLoc DL = MI.getDebugLoc(); 511 if (!DL.isUnknown()) { // Print source line info. 512 EmitDebugLoc(DL, MF, CommentOS); 513 CommentOS << '\n'; 514 } 515 516 // Check for spills and reloads 517 int FI; 518 519 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 520 521 // We assume a single instruction only has a spill or reload, not 522 // both. 523 const MachineMemOperand *MMO; 524 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 525 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 526 MMO = *MI.memoperands_begin(); 527 CommentOS << MMO->getSize() << "-byte Reload\n"; 528 } 529 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 530 if (FrameInfo->isSpillSlotObjectIndex(FI)) 531 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 532 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 533 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 534 MMO = *MI.memoperands_begin(); 535 CommentOS << MMO->getSize() << "-byte Spill\n"; 536 } 537 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 538 if (FrameInfo->isSpillSlotObjectIndex(FI)) 539 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 540 } 541 542 // Check for spill-induced copies 543 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 544 CommentOS << " Reload Reuse\n"; 545} 546 547/// EmitImplicitDef - This method emits the specified machine instruction 548/// that is an implicit def. 549static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 550 unsigned RegNo = MI->getOperand(0).getReg(); 551 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 552 AP.TM.getRegisterInfo()->getName(RegNo)); 553 AP.OutStreamer.AddBlankLine(); 554} 555 556static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 557 std::string Str = "kill:"; 558 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 559 const MachineOperand &Op = MI->getOperand(i); 560 assert(Op.isReg() && "KILL instruction must have only register operands"); 561 Str += ' '; 562 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 563 Str += (Op.isDef() ? "<def>" : "<kill>"); 564 } 565 AP.OutStreamer.AddComment(Str); 566 AP.OutStreamer.AddBlankLine(); 567} 568 569/// EmitDebugValueComment - This method handles the target-independent form 570/// of DBG_VALUE, returning true if it was able to do so. A false return 571/// means the target will need to handle MI in EmitInstruction. 572static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 573 // This code handles only the 3-operand target-independent form. 574 if (MI->getNumOperands() != 3) 575 return false; 576 577 SmallString<128> Str; 578 raw_svector_ostream OS(Str); 579 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 580 581 // cast away const; DIetc do not take const operands for some reason. 582 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 583 if (V.getContext().isSubprogram()) 584 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 585 OS << V.getName() << " <- "; 586 587 // Register or immediate value. Register 0 means undef. 588 if (MI->getOperand(0).isFPImm()) { 589 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 590 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 591 OS << (double)APF.convertToFloat(); 592 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 593 OS << APF.convertToDouble(); 594 } else { 595 // There is no good way to print long double. Convert a copy to 596 // double. Ah well, it's only a comment. 597 bool ignored; 598 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 599 &ignored); 600 OS << "(long double) " << APF.convertToDouble(); 601 } 602 } else if (MI->getOperand(0).isImm()) { 603 OS << MI->getOperand(0).getImm(); 604 } else { 605 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 606 if (MI->getOperand(0).getReg() == 0) { 607 // Suppress offset, it is not meaningful here. 608 OS << "undef"; 609 // NOTE: Want this comment at start of line, don't emit with AddComment. 610 AP.OutStreamer.EmitRawText(OS.str()); 611 return true; 612 } 613 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 614 } 615 616 OS << '+' << MI->getOperand(1).getImm(); 617 // NOTE: Want this comment at start of line, don't emit with AddComment. 618 AP.OutStreamer.EmitRawText(OS.str()); 619 return true; 620} 621 622/// EmitFunctionBody - This method emits the body and trailer for a 623/// function. 624void AsmPrinter::EmitFunctionBody() { 625 // Emit target-specific gunk before the function body. 626 EmitFunctionBodyStart(); 627 628 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 629 630 // Print out code for the function. 631 bool HasAnyRealCode = false; 632 const MachineInstr *LastMI = 0; 633 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 634 I != E; ++I) { 635 // Print a label for the basic block. 636 EmitBasicBlockStart(I); 637 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 638 II != IE; ++II) { 639 LastMI = II; 640 641 // Print the assembly for the instruction. 642 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 643 !II->isDebugValue()) { 644 HasAnyRealCode = true; 645 ++EmittedInsts; 646 } 647 648 if (ShouldPrintDebugScopes) { 649 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 650 DD->beginInstruction(II); 651 } 652 653 if (isVerbose()) 654 EmitComments(*II, OutStreamer.GetCommentOS()); 655 656 switch (II->getOpcode()) { 657 case TargetOpcode::PROLOG_LABEL: 658 case TargetOpcode::EH_LABEL: 659 case TargetOpcode::GC_LABEL: 660 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 661 break; 662 case TargetOpcode::INLINEASM: 663 EmitInlineAsm(II); 664 break; 665 case TargetOpcode::DBG_VALUE: 666 if (isVerbose()) { 667 if (!EmitDebugValueComment(II, *this)) 668 EmitInstruction(II); 669 } 670 break; 671 case TargetOpcode::IMPLICIT_DEF: 672 if (isVerbose()) EmitImplicitDef(II, *this); 673 break; 674 case TargetOpcode::KILL: 675 if (isVerbose()) EmitKill(II, *this); 676 break; 677 default: 678 EmitInstruction(II); 679 break; 680 } 681 682 if (ShouldPrintDebugScopes) { 683 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 684 DD->endInstruction(II); 685 } 686 } 687 } 688 689 // If the last instruction was a prolog label, then we have a situation where 690 // we emitted a prolog but no function body. This results in the ending prolog 691 // label equaling the end of function label and an invalid "row" in the 692 // FDE. We need to emit a noop in this situation so that the FDE's rows are 693 // valid. 694 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 695 696 // If the function is empty and the object file uses .subsections_via_symbols, 697 // then we need to emit *something* to the function body to prevent the 698 // labels from collapsing together. Just emit a noop. 699 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 700 MCInst Noop; 701 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 702 if (Noop.getOpcode()) { 703 OutStreamer.AddComment("avoids zero-length function"); 704 OutStreamer.EmitInstruction(Noop); 705 } else // Target not mc-ized yet. 706 OutStreamer.EmitRawText(StringRef("\tnop\n")); 707 } 708 709 // Emit target-specific gunk after the function body. 710 EmitFunctionBodyEnd(); 711 712 // If the target wants a .size directive for the size of the function, emit 713 // it. 714 if (MAI->hasDotTypeDotSizeDirective()) { 715 // Create a symbol for the end of function, so we can get the size as 716 // difference between the function label and the temp label. 717 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 718 OutStreamer.EmitLabel(FnEndLabel); 719 720 const MCExpr *SizeExp = 721 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 722 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 723 OutContext); 724 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 725 } 726 727 // Emit post-function debug information. 728 if (DD) { 729 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 730 DD->endFunction(MF); 731 } 732 if (DE) { 733 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 734 DE->EndFunction(); 735 } 736 MMI->EndFunction(); 737 738 // Print out jump tables referenced by the function. 739 EmitJumpTableInfo(); 740 741 OutStreamer.AddBlankLine(); 742} 743 744/// getDebugValueLocation - Get location information encoded by DBG_VALUE 745/// operands. 746MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const { 747 // Target specific DBG_VALUE instructions are handled by each target. 748 return MachineLocation(); 749} 750 751bool AsmPrinter::doFinalization(Module &M) { 752 // Emit global variables. 753 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 754 I != E; ++I) 755 EmitGlobalVariable(I); 756 757 // Finalize debug and EH information. 758 if (DE) { 759 { 760 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 761 DE->EndModule(); 762 } 763 delete DE; DE = 0; 764 } 765 if (DD) { 766 { 767 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 768 DD->endModule(); 769 } 770 delete DD; DD = 0; 771 } 772 773 // If the target wants to know about weak references, print them all. 774 if (MAI->getWeakRefDirective()) { 775 // FIXME: This is not lazy, it would be nice to only print weak references 776 // to stuff that is actually used. Note that doing so would require targets 777 // to notice uses in operands (due to constant exprs etc). This should 778 // happen with the MC stuff eventually. 779 780 // Print out module-level global variables here. 781 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 782 I != E; ++I) { 783 if (!I->hasExternalWeakLinkage()) continue; 784 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 785 } 786 787 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 788 if (!I->hasExternalWeakLinkage()) continue; 789 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 790 } 791 } 792 793 if (MAI->hasSetDirective()) { 794 OutStreamer.AddBlankLine(); 795 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 796 I != E; ++I) { 797 MCSymbol *Name = Mang->getSymbol(I); 798 799 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 800 MCSymbol *Target = Mang->getSymbol(GV); 801 802 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 803 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 804 else if (I->hasWeakLinkage()) 805 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 806 else 807 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 808 809 EmitVisibility(Name, I->getVisibility()); 810 811 // Emit the directives as assignments aka .set: 812 OutStreamer.EmitAssignment(Name, 813 MCSymbolRefExpr::Create(Target, OutContext)); 814 } 815 } 816 817 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 818 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 819 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 820 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 821 MP->finishAssembly(*this); 822 823 // If we don't have any trampolines, then we don't require stack memory 824 // to be executable. Some targets have a directive to declare this. 825 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 826 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 827 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 828 OutStreamer.SwitchSection(S); 829 830 // Allow the target to emit any magic that it wants at the end of the file, 831 // after everything else has gone out. 832 EmitEndOfAsmFile(M); 833 834 delete Mang; Mang = 0; 835 MMI = 0; 836 837 OutStreamer.Finish(); 838 return false; 839} 840 841void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 842 this->MF = &MF; 843 // Get the function symbol. 844 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 845 846 if (isVerbose()) 847 LI = &getAnalysis<MachineLoopInfo>(); 848} 849 850namespace { 851 // SectionCPs - Keep track the alignment, constpool entries per Section. 852 struct SectionCPs { 853 const MCSection *S; 854 unsigned Alignment; 855 SmallVector<unsigned, 4> CPEs; 856 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 857 }; 858} 859 860/// EmitConstantPool - Print to the current output stream assembly 861/// representations of the constants in the constant pool MCP. This is 862/// used to print out constants which have been "spilled to memory" by 863/// the code generator. 864/// 865void AsmPrinter::EmitConstantPool() { 866 const MachineConstantPool *MCP = MF->getConstantPool(); 867 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 868 if (CP.empty()) return; 869 870 // Calculate sections for constant pool entries. We collect entries to go into 871 // the same section together to reduce amount of section switch statements. 872 SmallVector<SectionCPs, 4> CPSections; 873 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 874 const MachineConstantPoolEntry &CPE = CP[i]; 875 unsigned Align = CPE.getAlignment(); 876 877 SectionKind Kind; 878 switch (CPE.getRelocationInfo()) { 879 default: llvm_unreachable("Unknown section kind"); 880 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 881 case 1: 882 Kind = SectionKind::getReadOnlyWithRelLocal(); 883 break; 884 case 0: 885 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 886 case 4: Kind = SectionKind::getMergeableConst4(); break; 887 case 8: Kind = SectionKind::getMergeableConst8(); break; 888 case 16: Kind = SectionKind::getMergeableConst16();break; 889 default: Kind = SectionKind::getMergeableConst(); break; 890 } 891 } 892 893 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 894 895 // The number of sections are small, just do a linear search from the 896 // last section to the first. 897 bool Found = false; 898 unsigned SecIdx = CPSections.size(); 899 while (SecIdx != 0) { 900 if (CPSections[--SecIdx].S == S) { 901 Found = true; 902 break; 903 } 904 } 905 if (!Found) { 906 SecIdx = CPSections.size(); 907 CPSections.push_back(SectionCPs(S, Align)); 908 } 909 910 if (Align > CPSections[SecIdx].Alignment) 911 CPSections[SecIdx].Alignment = Align; 912 CPSections[SecIdx].CPEs.push_back(i); 913 } 914 915 // Now print stuff into the calculated sections. 916 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 917 OutStreamer.SwitchSection(CPSections[i].S); 918 EmitAlignment(Log2_32(CPSections[i].Alignment)); 919 920 unsigned Offset = 0; 921 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 922 unsigned CPI = CPSections[i].CPEs[j]; 923 MachineConstantPoolEntry CPE = CP[CPI]; 924 925 // Emit inter-object padding for alignment. 926 unsigned AlignMask = CPE.getAlignment() - 1; 927 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 928 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 929 930 const Type *Ty = CPE.getType(); 931 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 932 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 933 934 if (CPE.isMachineConstantPoolEntry()) 935 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 936 else 937 EmitGlobalConstant(CPE.Val.ConstVal); 938 } 939 } 940} 941 942/// EmitJumpTableInfo - Print assembly representations of the jump tables used 943/// by the current function to the current output stream. 944/// 945void AsmPrinter::EmitJumpTableInfo() { 946 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 947 if (MJTI == 0) return; 948 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 949 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 950 if (JT.empty()) return; 951 952 // Pick the directive to use to print the jump table entries, and switch to 953 // the appropriate section. 954 const Function *F = MF->getFunction(); 955 bool JTInDiffSection = false; 956 if (// In PIC mode, we need to emit the jump table to the same section as the 957 // function body itself, otherwise the label differences won't make sense. 958 // FIXME: Need a better predicate for this: what about custom entries? 959 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 960 // We should also do if the section name is NULL or function is declared 961 // in discardable section 962 // FIXME: this isn't the right predicate, should be based on the MCSection 963 // for the function. 964 F->isWeakForLinker()) { 965 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 966 } else { 967 // Otherwise, drop it in the readonly section. 968 const MCSection *ReadOnlySection = 969 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 970 OutStreamer.SwitchSection(ReadOnlySection); 971 JTInDiffSection = true; 972 } 973 974 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 975 976 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 977 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 978 979 // If this jump table was deleted, ignore it. 980 if (JTBBs.empty()) continue; 981 982 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 983 // .set directive for each unique entry. This reduces the number of 984 // relocations the assembler will generate for the jump table. 985 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 986 MAI->hasSetDirective()) { 987 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 988 const TargetLowering *TLI = TM.getTargetLowering(); 989 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 990 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 991 const MachineBasicBlock *MBB = JTBBs[ii]; 992 if (!EmittedSets.insert(MBB)) continue; 993 994 // .set LJTSet, LBB32-base 995 const MCExpr *LHS = 996 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 997 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 998 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 999 } 1000 } 1001 1002 // On some targets (e.g. Darwin) we want to emit two consequtive labels 1003 // before each jump table. The first label is never referenced, but tells 1004 // the assembler and linker the extents of the jump table object. The 1005 // second label is actually referenced by the code. 1006 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1007 // FIXME: This doesn't have to have any specific name, just any randomly 1008 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1009 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1010 1011 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1012 1013 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1014 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1015 } 1016} 1017 1018/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1019/// current stream. 1020void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1021 const MachineBasicBlock *MBB, 1022 unsigned UID) const { 1023 const MCExpr *Value = 0; 1024 switch (MJTI->getEntryKind()) { 1025 case MachineJumpTableInfo::EK_Inline: 1026 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1027 case MachineJumpTableInfo::EK_Custom32: 1028 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1029 OutContext); 1030 break; 1031 case MachineJumpTableInfo::EK_BlockAddress: 1032 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1033 // .word LBB123 1034 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1035 break; 1036 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1037 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1038 // with a relocation as gp-relative, e.g.: 1039 // .gprel32 LBB123 1040 MCSymbol *MBBSym = MBB->getSymbol(); 1041 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1042 return; 1043 } 1044 1045 case MachineJumpTableInfo::EK_LabelDifference32: { 1046 // EK_LabelDifference32 - Each entry is the address of the block minus 1047 // the address of the jump table. This is used for PIC jump tables where 1048 // gprel32 is not supported. e.g.: 1049 // .word LBB123 - LJTI1_2 1050 // If the .set directive is supported, this is emitted as: 1051 // .set L4_5_set_123, LBB123 - LJTI1_2 1052 // .word L4_5_set_123 1053 1054 // If we have emitted set directives for the jump table entries, print 1055 // them rather than the entries themselves. If we're emitting PIC, then 1056 // emit the table entries as differences between two text section labels. 1057 if (MAI->hasSetDirective()) { 1058 // If we used .set, reference the .set's symbol. 1059 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1060 OutContext); 1061 break; 1062 } 1063 // Otherwise, use the difference as the jump table entry. 1064 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1065 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1066 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1067 break; 1068 } 1069 } 1070 1071 assert(Value && "Unknown entry kind!"); 1072 1073 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1074 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1075} 1076 1077 1078/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1079/// special global used by LLVM. If so, emit it and return true, otherwise 1080/// do nothing and return false. 1081bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1082 if (GV->getName() == "llvm.used") { 1083 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1084 EmitLLVMUsedList(GV->getInitializer()); 1085 return true; 1086 } 1087 1088 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1089 if (GV->getSection() == "llvm.metadata" || 1090 GV->hasAvailableExternallyLinkage()) 1091 return true; 1092 1093 if (!GV->hasAppendingLinkage()) return false; 1094 1095 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1096 1097 const TargetData *TD = TM.getTargetData(); 1098 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1099 if (GV->getName() == "llvm.global_ctors") { 1100 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1101 EmitAlignment(Align); 1102 EmitXXStructorList(GV->getInitializer()); 1103 1104 if (TM.getRelocationModel() == Reloc::Static && 1105 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1106 StringRef Sym(".constructors_used"); 1107 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1108 MCSA_Reference); 1109 } 1110 return true; 1111 } 1112 1113 if (GV->getName() == "llvm.global_dtors") { 1114 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1115 EmitAlignment(Align); 1116 EmitXXStructorList(GV->getInitializer()); 1117 1118 if (TM.getRelocationModel() == Reloc::Static && 1119 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1120 StringRef Sym(".destructors_used"); 1121 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1122 MCSA_Reference); 1123 } 1124 return true; 1125 } 1126 1127 return false; 1128} 1129 1130/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1131/// global in the specified llvm.used list for which emitUsedDirectiveFor 1132/// is true, as being used with this directive. 1133void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1134 // Should be an array of 'i8*'. 1135 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1136 if (InitList == 0) return; 1137 1138 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1139 const GlobalValue *GV = 1140 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1141 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1142 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1143 } 1144} 1145 1146/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1147/// function pointers, ignoring the init priority. 1148void AsmPrinter::EmitXXStructorList(Constant *List) { 1149 // Should be an array of '{ int, void ()* }' structs. The first value is the 1150 // init priority, which we ignore. 1151 if (!isa<ConstantArray>(List)) return; 1152 ConstantArray *InitList = cast<ConstantArray>(List); 1153 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1154 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1155 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1156 1157 if (CS->getOperand(1)->isNullValue()) 1158 return; // Found a null terminator, exit printing. 1159 // Emit the function pointer. 1160 EmitGlobalConstant(CS->getOperand(1)); 1161 } 1162} 1163 1164//===--------------------------------------------------------------------===// 1165// Emission and print routines 1166// 1167 1168/// EmitInt8 - Emit a byte directive and value. 1169/// 1170void AsmPrinter::EmitInt8(int Value) const { 1171 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1172} 1173 1174/// EmitInt16 - Emit a short directive and value. 1175/// 1176void AsmPrinter::EmitInt16(int Value) const { 1177 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1178} 1179 1180/// EmitInt32 - Emit a long directive and value. 1181/// 1182void AsmPrinter::EmitInt32(int Value) const { 1183 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1184} 1185 1186/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1187/// in bytes of the directive is specified by Size and Hi/Lo specify the 1188/// labels. This implicitly uses .set if it is available. 1189void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1190 unsigned Size) const { 1191 // Get the Hi-Lo expression. 1192 const MCExpr *Diff = 1193 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1194 MCSymbolRefExpr::Create(Lo, OutContext), 1195 OutContext); 1196 1197 if (!MAI->hasSetDirective()) { 1198 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1199 return; 1200 } 1201 1202 // Otherwise, emit with .set (aka assignment). 1203 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1204 OutStreamer.EmitAssignment(SetLabel, Diff); 1205 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1206} 1207 1208/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1209/// where the size in bytes of the directive is specified by Size and Hi/Lo 1210/// specify the labels. This implicitly uses .set if it is available. 1211void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1212 const MCSymbol *Lo, unsigned Size) 1213 const { 1214 1215 // Emit Hi+Offset - Lo 1216 // Get the Hi+Offset expression. 1217 const MCExpr *Plus = 1218 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1219 MCConstantExpr::Create(Offset, OutContext), 1220 OutContext); 1221 1222 // Get the Hi+Offset-Lo expression. 1223 const MCExpr *Diff = 1224 MCBinaryExpr::CreateSub(Plus, 1225 MCSymbolRefExpr::Create(Lo, OutContext), 1226 OutContext); 1227 1228 if (!MAI->hasSetDirective()) 1229 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1230 else { 1231 // Otherwise, emit with .set (aka assignment). 1232 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1233 OutStreamer.EmitAssignment(SetLabel, Diff); 1234 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1235 } 1236} 1237 1238/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1239/// where the size in bytes of the directive is specified by Size and Label 1240/// specifies the label. This implicitly uses .set if it is available. 1241void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1242 unsigned Size) 1243 const { 1244 1245 // Emit Label+Offset 1246 const MCExpr *Plus = 1247 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1248 MCConstantExpr::Create(Offset, OutContext), 1249 OutContext); 1250 1251 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1252} 1253 1254 1255//===----------------------------------------------------------------------===// 1256 1257// EmitAlignment - Emit an alignment directive to the specified power of 1258// two boundary. For example, if you pass in 3 here, you will get an 8 1259// byte alignment. If a global value is specified, and if that global has 1260// an explicit alignment requested, it will override the alignment request 1261// if required for correctness. 1262// 1263void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1264 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1265 1266 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1267 1268 if (getCurrentSection()->getKind().isText()) 1269 OutStreamer.EmitCodeAlignment(1 << NumBits); 1270 else 1271 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1272} 1273 1274//===----------------------------------------------------------------------===// 1275// Constant emission. 1276//===----------------------------------------------------------------------===// 1277 1278/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1279/// 1280static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1281 MCContext &Ctx = AP.OutContext; 1282 1283 if (CV->isNullValue() || isa<UndefValue>(CV)) 1284 return MCConstantExpr::Create(0, Ctx); 1285 1286 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1287 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1288 1289 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1290 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1291 1292 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1293 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1294 1295 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1296 if (CE == 0) { 1297 llvm_unreachable("Unknown constant value to lower!"); 1298 return MCConstantExpr::Create(0, Ctx); 1299 } 1300 1301 switch (CE->getOpcode()) { 1302 default: 1303 // If the code isn't optimized, there may be outstanding folding 1304 // opportunities. Attempt to fold the expression using TargetData as a 1305 // last resort before giving up. 1306 if (Constant *C = 1307 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1308 if (C != CE) 1309 return LowerConstant(C, AP); 1310 1311 // Otherwise report the problem to the user. 1312 { 1313 std::string S; 1314 raw_string_ostream OS(S); 1315 OS << "Unsupported expression in static initializer: "; 1316 WriteAsOperand(OS, CE, /*PrintType=*/false, 1317 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1318 report_fatal_error(OS.str()); 1319 } 1320 return MCConstantExpr::Create(0, Ctx); 1321 case Instruction::GetElementPtr: { 1322 const TargetData &TD = *AP.TM.getTargetData(); 1323 // Generate a symbolic expression for the byte address 1324 const Constant *PtrVal = CE->getOperand(0); 1325 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1326 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1327 IdxVec.size()); 1328 1329 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1330 if (Offset == 0) 1331 return Base; 1332 1333 // Truncate/sext the offset to the pointer size. 1334 if (TD.getPointerSizeInBits() != 64) { 1335 int SExtAmount = 64-TD.getPointerSizeInBits(); 1336 Offset = (Offset << SExtAmount) >> SExtAmount; 1337 } 1338 1339 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1340 Ctx); 1341 } 1342 1343 case Instruction::Trunc: 1344 // We emit the value and depend on the assembler to truncate the generated 1345 // expression properly. This is important for differences between 1346 // blockaddress labels. Since the two labels are in the same function, it 1347 // is reasonable to treat their delta as a 32-bit value. 1348 // FALL THROUGH. 1349 case Instruction::BitCast: 1350 return LowerConstant(CE->getOperand(0), AP); 1351 1352 case Instruction::IntToPtr: { 1353 const TargetData &TD = *AP.TM.getTargetData(); 1354 // Handle casts to pointers by changing them into casts to the appropriate 1355 // integer type. This promotes constant folding and simplifies this code. 1356 Constant *Op = CE->getOperand(0); 1357 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1358 false/*ZExt*/); 1359 return LowerConstant(Op, AP); 1360 } 1361 1362 case Instruction::PtrToInt: { 1363 const TargetData &TD = *AP.TM.getTargetData(); 1364 // Support only foldable casts to/from pointers that can be eliminated by 1365 // changing the pointer to the appropriately sized integer type. 1366 Constant *Op = CE->getOperand(0); 1367 const Type *Ty = CE->getType(); 1368 1369 const MCExpr *OpExpr = LowerConstant(Op, AP); 1370 1371 // We can emit the pointer value into this slot if the slot is an 1372 // integer slot equal to the size of the pointer. 1373 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1374 return OpExpr; 1375 1376 // Otherwise the pointer is smaller than the resultant integer, mask off 1377 // the high bits so we are sure to get a proper truncation if the input is 1378 // a constant expr. 1379 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1380 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1381 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1382 } 1383 1384 // The MC library also has a right-shift operator, but it isn't consistently 1385 // signed or unsigned between different targets. 1386 case Instruction::Add: 1387 case Instruction::Sub: 1388 case Instruction::Mul: 1389 case Instruction::SDiv: 1390 case Instruction::SRem: 1391 case Instruction::Shl: 1392 case Instruction::And: 1393 case Instruction::Or: 1394 case Instruction::Xor: { 1395 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1396 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1397 switch (CE->getOpcode()) { 1398 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1399 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1400 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1401 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1402 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1403 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1404 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1405 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1406 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1407 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1408 } 1409 } 1410 } 1411} 1412 1413static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1414 AsmPrinter &AP); 1415 1416static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1417 AsmPrinter &AP) { 1418 if (AddrSpace != 0 || !CA->isString()) { 1419 // Not a string. Print the values in successive locations 1420 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1421 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1422 return; 1423 } 1424 1425 // Otherwise, it can be emitted as .ascii. 1426 SmallVector<char, 128> TmpVec; 1427 TmpVec.reserve(CA->getNumOperands()); 1428 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1429 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1430 1431 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1432} 1433 1434static void EmitGlobalConstantVector(const ConstantVector *CV, 1435 unsigned AddrSpace, AsmPrinter &AP) { 1436 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1437 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1438} 1439 1440static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1441 unsigned AddrSpace, AsmPrinter &AP) { 1442 // Print the fields in successive locations. Pad to align if needed! 1443 const TargetData *TD = AP.TM.getTargetData(); 1444 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1445 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1446 uint64_t SizeSoFar = 0; 1447 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1448 const Constant *Field = CS->getOperand(i); 1449 1450 // Check if padding is needed and insert one or more 0s. 1451 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1452 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1453 - Layout->getElementOffset(i)) - FieldSize; 1454 SizeSoFar += FieldSize + PadSize; 1455 1456 // Now print the actual field value. 1457 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1458 1459 // Insert padding - this may include padding to increase the size of the 1460 // current field up to the ABI size (if the struct is not packed) as well 1461 // as padding to ensure that the next field starts at the right offset. 1462 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1463 } 1464 assert(SizeSoFar == Layout->getSizeInBytes() && 1465 "Layout of constant struct may be incorrect!"); 1466} 1467 1468static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1469 AsmPrinter &AP) { 1470 // FP Constants are printed as integer constants to avoid losing 1471 // precision. 1472 if (CFP->getType()->isDoubleTy()) { 1473 if (AP.isVerbose()) { 1474 double Val = CFP->getValueAPF().convertToDouble(); 1475 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1476 } 1477 1478 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1479 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1480 return; 1481 } 1482 1483 if (CFP->getType()->isFloatTy()) { 1484 if (AP.isVerbose()) { 1485 float Val = CFP->getValueAPF().convertToFloat(); 1486 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1487 } 1488 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1489 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1490 return; 1491 } 1492 1493 if (CFP->getType()->isX86_FP80Ty()) { 1494 // all long double variants are printed as hex 1495 // API needed to prevent premature destruction 1496 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1497 const uint64_t *p = API.getRawData(); 1498 if (AP.isVerbose()) { 1499 // Convert to double so we can print the approximate val as a comment. 1500 APFloat DoubleVal = CFP->getValueAPF(); 1501 bool ignored; 1502 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1503 &ignored); 1504 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1505 << DoubleVal.convertToDouble() << '\n'; 1506 } 1507 1508 if (AP.TM.getTargetData()->isBigEndian()) { 1509 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1510 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1511 } else { 1512 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1513 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1514 } 1515 1516 // Emit the tail padding for the long double. 1517 const TargetData &TD = *AP.TM.getTargetData(); 1518 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1519 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1520 return; 1521 } 1522 1523 assert(CFP->getType()->isPPC_FP128Ty() && 1524 "Floating point constant type not handled"); 1525 // All long double variants are printed as hex 1526 // API needed to prevent premature destruction. 1527 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1528 const uint64_t *p = API.getRawData(); 1529 if (AP.TM.getTargetData()->isBigEndian()) { 1530 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1531 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1532 } else { 1533 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1534 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1535 } 1536} 1537 1538static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1539 unsigned AddrSpace, AsmPrinter &AP) { 1540 const TargetData *TD = AP.TM.getTargetData(); 1541 unsigned BitWidth = CI->getBitWidth(); 1542 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1543 1544 // We don't expect assemblers to support integer data directives 1545 // for more than 64 bits, so we emit the data in at most 64-bit 1546 // quantities at a time. 1547 const uint64_t *RawData = CI->getValue().getRawData(); 1548 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1549 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1550 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1551 } 1552} 1553 1554static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1555 AsmPrinter &AP) { 1556 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1557 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1558 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1559 } 1560 1561 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1562 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1563 switch (Size) { 1564 case 1: 1565 case 2: 1566 case 4: 1567 case 8: 1568 if (AP.isVerbose()) 1569 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1570 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1571 return; 1572 default: 1573 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1574 return; 1575 } 1576 } 1577 1578 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1579 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1580 1581 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1582 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1583 1584 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1585 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1586 1587 if (isa<ConstantPointerNull>(CV)) { 1588 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1589 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1590 return; 1591 } 1592 1593 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1594 return EmitGlobalConstantVector(V, AddrSpace, AP); 1595 1596 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1597 // thread the streamer with EmitValue. 1598 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1599 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1600 AddrSpace); 1601} 1602 1603/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1604void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1605 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1606 if (Size) 1607 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1608 else if (MAI->hasSubsectionsViaSymbols()) { 1609 // If the global has zero size, emit a single byte so that two labels don't 1610 // look like they are at the same location. 1611 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1612 } 1613} 1614 1615void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1616 // Target doesn't support this yet! 1617 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1618} 1619 1620void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1621 if (Offset > 0) 1622 OS << '+' << Offset; 1623 else if (Offset < 0) 1624 OS << Offset; 1625} 1626 1627//===----------------------------------------------------------------------===// 1628// Symbol Lowering Routines. 1629//===----------------------------------------------------------------------===// 1630 1631/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1632/// temporary label with the specified stem and unique ID. 1633MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1634 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1635 Name + Twine(ID)); 1636} 1637 1638/// GetTempSymbol - Return an assembler temporary label with the specified 1639/// stem. 1640MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1641 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1642 Name); 1643} 1644 1645 1646MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1647 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1648} 1649 1650MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1651 return MMI->getAddrLabelSymbol(BB); 1652} 1653 1654/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1655MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1656 return OutContext.GetOrCreateSymbol 1657 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1658 + "_" + Twine(CPID)); 1659} 1660 1661/// GetJTISymbol - Return the symbol for the specified jump table entry. 1662MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1663 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1664} 1665 1666/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1667/// FIXME: privatize to AsmPrinter. 1668MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1669 return OutContext.GetOrCreateSymbol 1670 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1671 Twine(UID) + "_set_" + Twine(MBBID)); 1672} 1673 1674/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1675/// global value name as its base, with the specified suffix, and where the 1676/// symbol is forced to have private linkage if ForcePrivate is true. 1677MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1678 StringRef Suffix, 1679 bool ForcePrivate) const { 1680 SmallString<60> NameStr; 1681 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1682 NameStr.append(Suffix.begin(), Suffix.end()); 1683 return OutContext.GetOrCreateSymbol(NameStr.str()); 1684} 1685 1686/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1687/// ExternalSymbol. 1688MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1689 SmallString<60> NameStr; 1690 Mang->getNameWithPrefix(NameStr, Sym); 1691 return OutContext.GetOrCreateSymbol(NameStr.str()); 1692} 1693 1694 1695 1696/// PrintParentLoopComment - Print comments about parent loops of this one. 1697static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1698 unsigned FunctionNumber) { 1699 if (Loop == 0) return; 1700 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1701 OS.indent(Loop->getLoopDepth()*2) 1702 << "Parent Loop BB" << FunctionNumber << "_" 1703 << Loop->getHeader()->getNumber() 1704 << " Depth=" << Loop->getLoopDepth() << '\n'; 1705} 1706 1707 1708/// PrintChildLoopComment - Print comments about child loops within 1709/// the loop for this basic block, with nesting. 1710static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1711 unsigned FunctionNumber) { 1712 // Add child loop information 1713 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1714 OS.indent((*CL)->getLoopDepth()*2) 1715 << "Child Loop BB" << FunctionNumber << "_" 1716 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1717 << '\n'; 1718 PrintChildLoopComment(OS, *CL, FunctionNumber); 1719 } 1720} 1721 1722/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1723static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1724 const MachineLoopInfo *LI, 1725 const AsmPrinter &AP) { 1726 // Add loop depth information 1727 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1728 if (Loop == 0) return; 1729 1730 MachineBasicBlock *Header = Loop->getHeader(); 1731 assert(Header && "No header for loop"); 1732 1733 // If this block is not a loop header, just print out what is the loop header 1734 // and return. 1735 if (Header != &MBB) { 1736 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1737 Twine(AP.getFunctionNumber())+"_" + 1738 Twine(Loop->getHeader()->getNumber())+ 1739 " Depth="+Twine(Loop->getLoopDepth())); 1740 return; 1741 } 1742 1743 // Otherwise, it is a loop header. Print out information about child and 1744 // parent loops. 1745 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1746 1747 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1748 1749 OS << "=>"; 1750 OS.indent(Loop->getLoopDepth()*2-2); 1751 1752 OS << "This "; 1753 if (Loop->empty()) 1754 OS << "Inner "; 1755 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1756 1757 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1758} 1759 1760 1761/// EmitBasicBlockStart - This method prints the label for the specified 1762/// MachineBasicBlock, an alignment (if present) and a comment describing 1763/// it if appropriate. 1764void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1765 // Emit an alignment directive for this block, if needed. 1766 if (unsigned Align = MBB->getAlignment()) 1767 EmitAlignment(Log2_32(Align)); 1768 1769 // If the block has its address taken, emit any labels that were used to 1770 // reference the block. It is possible that there is more than one label 1771 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1772 // the references were generated. 1773 if (MBB->hasAddressTaken()) { 1774 const BasicBlock *BB = MBB->getBasicBlock(); 1775 if (isVerbose()) 1776 OutStreamer.AddComment("Block address taken"); 1777 1778 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1779 1780 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1781 OutStreamer.EmitLabel(Syms[i]); 1782 } 1783 1784 // Print the main label for the block. 1785 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1786 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1787 if (const BasicBlock *BB = MBB->getBasicBlock()) 1788 if (BB->hasName()) 1789 OutStreamer.AddComment("%" + BB->getName()); 1790 1791 EmitBasicBlockLoopComments(*MBB, LI, *this); 1792 1793 // NOTE: Want this comment at start of line, don't emit with AddComment. 1794 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1795 Twine(MBB->getNumber()) + ":"); 1796 } 1797 } else { 1798 if (isVerbose()) { 1799 if (const BasicBlock *BB = MBB->getBasicBlock()) 1800 if (BB->hasName()) 1801 OutStreamer.AddComment("%" + BB->getName()); 1802 EmitBasicBlockLoopComments(*MBB, LI, *this); 1803 } 1804 1805 OutStreamer.EmitLabel(MBB->getSymbol()); 1806 } 1807} 1808 1809void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1810 MCSymbolAttr Attr = MCSA_Invalid; 1811 1812 switch (Visibility) { 1813 default: break; 1814 case GlobalValue::HiddenVisibility: 1815 Attr = MAI->getHiddenVisibilityAttr(); 1816 break; 1817 case GlobalValue::ProtectedVisibility: 1818 Attr = MAI->getProtectedVisibilityAttr(); 1819 break; 1820 } 1821 1822 if (Attr != MCSA_Invalid) 1823 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1824} 1825 1826/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1827/// exactly one predecessor and the control transfer mechanism between 1828/// the predecessor and this block is a fall-through. 1829bool AsmPrinter:: 1830isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1831 // If this is a landing pad, it isn't a fall through. If it has no preds, 1832 // then nothing falls through to it. 1833 if (MBB->isLandingPad() || MBB->pred_empty()) 1834 return false; 1835 1836 // If there isn't exactly one predecessor, it can't be a fall through. 1837 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1838 ++PI2; 1839 if (PI2 != MBB->pred_end()) 1840 return false; 1841 1842 // The predecessor has to be immediately before this block. 1843 const MachineBasicBlock *Pred = *PI; 1844 1845 if (!Pred->isLayoutSuccessor(MBB)) 1846 return false; 1847 1848 // If the block is completely empty, then it definitely does fall through. 1849 if (Pred->empty()) 1850 return true; 1851 1852 // Otherwise, check the last instruction. 1853 const MachineInstr &LastInst = Pred->back(); 1854 return !LastInst.getDesc().isBarrier(); 1855} 1856 1857 1858 1859GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1860 if (!S->usesMetadata()) 1861 return 0; 1862 1863 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1864 gcp_map_type::iterator GCPI = GCMap.find(S); 1865 if (GCPI != GCMap.end()) 1866 return GCPI->second; 1867 1868 const char *Name = S->getName().c_str(); 1869 1870 for (GCMetadataPrinterRegistry::iterator 1871 I = GCMetadataPrinterRegistry::begin(), 1872 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1873 if (strcmp(Name, I->getName()) == 0) { 1874 GCMetadataPrinter *GMP = I->instantiate(); 1875 GMP->S = S; 1876 GCMap.insert(std::make_pair(S, GMP)); 1877 return GMP; 1878 } 1879 1880 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1881 return 0; 1882} 1883 1884