AsmPrinter.cpp revision a95f589c757c8c857096a07e0d376ca9aaec6c2c
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#ifndef ANDROID_TARGET_BUILD 17# include "DwarfDebug.h" 18# include "DwarfException.h" 19#endif // ANDROID_TARGET_BUILD 20#include "llvm/Module.h" 21#include "llvm/CodeGen/GCMetadataPrinter.h" 22#include "llvm/CodeGen/MachineConstantPool.h" 23#include "llvm/CodeGen/MachineFrameInfo.h" 24#include "llvm/CodeGen/MachineFunction.h" 25#include "llvm/CodeGen/MachineJumpTableInfo.h" 26#include "llvm/CodeGen/MachineLoopInfo.h" 27#include "llvm/CodeGen/MachineModuleInfo.h" 28#include "llvm/Analysis/ConstantFolding.h" 29#include "llvm/Analysis/DebugInfo.h" 30#include "llvm/MC/MCAsmInfo.h" 31#include "llvm/MC/MCContext.h" 32#include "llvm/MC/MCExpr.h" 33#include "llvm/MC/MCInst.h" 34#include "llvm/MC/MCSection.h" 35#include "llvm/MC/MCStreamer.h" 36#include "llvm/MC/MCSymbol.h" 37#include "llvm/Target/Mangler.h" 38#include "llvm/Target/TargetData.h" 39#include "llvm/Target/TargetInstrInfo.h" 40#include "llvm/Target/TargetLowering.h" 41#include "llvm/Target/TargetLoweringObjectFile.h" 42#include "llvm/Target/TargetRegisterInfo.h" 43#include "llvm/ADT/SmallString.h" 44#include "llvm/ADT/Statistic.h" 45#include "llvm/Support/ErrorHandling.h" 46#include "llvm/Support/Format.h" 47#include "llvm/Support/Timer.h" 48#include <ctype.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", 0/*no loc cookie*/); 185 OutStreamer.AddComment("End of file scope inline assembly"); 186 OutStreamer.AddBlankLine(); 187 } 188 189#ifndef ANDROID_TARGET_BUILD 190 if (MAI->doesSupportDebugInformation()) 191 DD = new DwarfDebug(this, &M); 192 193 if (MAI->doesSupportExceptionHandling()) 194 DE = new DwarfException(this); 195#endif // ANDROID_TARGET_BUILD 196 197 return false; 198} 199 200void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const { 201 switch ((GlobalValue::LinkageTypes)Linkage) { 202 case GlobalValue::CommonLinkage: 203 case GlobalValue::LinkOnceAnyLinkage: 204 case GlobalValue::LinkOnceODRLinkage: 205 case GlobalValue::WeakAnyLinkage: 206 case GlobalValue::WeakODRLinkage: 207 case GlobalValue::LinkerPrivateWeakLinkage: 208 case GlobalValue::LinkerPrivateWeakDefAutoLinkage: 209 if (MAI->getWeakDefDirective() != 0) { 210 // .globl _foo 211 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 212 213 if ((GlobalValue::LinkageTypes)Linkage != 214 GlobalValue::LinkerPrivateWeakDefAutoLinkage) 215 // .weak_definition _foo 216 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition); 217 else 218 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefAutoPrivate); 219 } else if (MAI->getLinkOnceDirective() != 0) { 220 // .globl _foo 221 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 222 //NOTE: linkonce is handled by the section the symbol was assigned to. 223 } else { 224 // .weak _foo 225 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak); 226 } 227 break; 228 case GlobalValue::DLLExportLinkage: 229 case GlobalValue::AppendingLinkage: 230 // FIXME: appending linkage variables should go into a section of 231 // their name or something. For now, just emit them as external. 232 case GlobalValue::ExternalLinkage: 233 // If external or appending, declare as a global symbol. 234 // .globl _foo 235 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 236 break; 237 case GlobalValue::PrivateLinkage: 238 case GlobalValue::InternalLinkage: 239 case GlobalValue::LinkerPrivateLinkage: 240 break; 241 default: 242 llvm_unreachable("Unknown linkage type!"); 243 } 244} 245 246 247/// EmitGlobalVariable - Emit the specified global variable to the .s file. 248void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) { 249 if (!GV->hasInitializer()) // External globals require no code. 250 return; 251 252 // Check to see if this is a special global used by LLVM, if so, emit it. 253 if (EmitSpecialLLVMGlobal(GV)) 254 return; 255 256 if (isVerbose()) { 257 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 258 /*PrintType=*/false, GV->getParent()); 259 OutStreamer.GetCommentOS() << '\n'; 260 } 261 262 MCSymbol *GVSym = Mang->getSymbol(GV); 263 EmitVisibility(GVSym, GV->getVisibility()); 264 265 if (MAI->hasDotTypeDotSizeDirective()) 266 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject); 267 268 SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM); 269 270 const TargetData *TD = TM.getTargetData(); 271 uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType()); 272 273 // If the alignment is specified, we *must* obey it. Overaligning a global 274 // with a specified alignment is a prompt way to break globals emitted to 275 // sections and expected to be contiguous (e.g. ObjC metadata). 276 unsigned AlignLog = getGVAlignmentLog2(GV, *TD); 277 278 // Handle common and BSS local symbols (.lcomm). 279 if (GVKind.isCommon() || GVKind.isBSSLocal()) { 280 if (Size == 0) Size = 1; // .comm Foo, 0 is undefined, avoid it. 281 282 if (isVerbose()) { 283 WriteAsOperand(OutStreamer.GetCommentOS(), GV, 284 /*PrintType=*/false, GV->getParent()); 285 OutStreamer.GetCommentOS() << '\n'; 286 } 287 288 // Handle common symbols. 289 if (GVKind.isCommon()) { 290 // .comm _foo, 42, 4 291 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 292 return; 293 } 294 295 // Handle local BSS symbols. 296 if (MAI->hasMachoZeroFillDirective()) { 297 const MCSection *TheSection = 298 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 299 // .zerofill __DATA, __bss, _foo, 400, 5 300 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 301 return; 302 } 303 304 if (MAI->hasLCOMMDirective()) { 305 // .lcomm _foo, 42 306 OutStreamer.EmitLocalCommonSymbol(GVSym, Size); 307 return; 308 } 309 310 // .local _foo 311 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local); 312 // .comm _foo, 42, 4 313 OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog); 314 return; 315 } 316 317 const MCSection *TheSection = 318 getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM); 319 320 // Handle the zerofill directive on darwin, which is a special form of BSS 321 // emission. 322 if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) { 323 if (Size == 0) Size = 1; // zerofill of 0 bytes is undefined. 324 325 // .globl _foo 326 OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global); 327 // .zerofill __DATA, __common, _foo, 400, 5 328 OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog); 329 return; 330 } 331 332 // Handle thread local data for mach-o which requires us to output an 333 // additional structure of data and mangle the original symbol so that we 334 // can reference it later. 335 if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) { 336 // Emit the .tbss symbol 337 MCSymbol *MangSym = 338 OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init")); 339 340 if (GVKind.isThreadBSS()) 341 OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog); 342 else if (GVKind.isThreadData()) { 343 OutStreamer.SwitchSection(TheSection); 344 345 EmitAlignment(AlignLog, GV); 346 OutStreamer.EmitLabel(MangSym); 347 348 EmitGlobalConstant(GV->getInitializer()); 349 } 350 351 OutStreamer.AddBlankLine(); 352 353 // Emit the variable struct for the runtime. 354 const MCSection *TLVSect 355 = getObjFileLowering().getTLSExtraDataSection(); 356 357 OutStreamer.SwitchSection(TLVSect); 358 // Emit the linkage here. 359 EmitLinkage(GV->getLinkage(), GVSym); 360 OutStreamer.EmitLabel(GVSym); 361 362 // Three pointers in size: 363 // - __tlv_bootstrap - used to make sure support exists 364 // - spare pointer, used when mapped by the runtime 365 // - pointer to mangled symbol above with initializer 366 unsigned PtrSize = TD->getPointerSizeInBits()/8; 367 OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("_tlv_bootstrap"), 368 PtrSize, 0); 369 OutStreamer.EmitIntValue(0, PtrSize, 0); 370 OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0); 371 372 OutStreamer.AddBlankLine(); 373 return; 374 } 375 376 OutStreamer.SwitchSection(TheSection); 377 378 EmitLinkage(GV->getLinkage(), GVSym); 379 EmitAlignment(AlignLog, GV); 380 381 OutStreamer.EmitLabel(GVSym); 382 383 EmitGlobalConstant(GV->getInitializer()); 384 385 if (MAI->hasDotTypeDotSizeDirective()) 386 // .size foo, 42 387 OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext)); 388 389 OutStreamer.AddBlankLine(); 390} 391 392/// EmitFunctionHeader - This method emits the header for the current 393/// function. 394void AsmPrinter::EmitFunctionHeader() { 395 // Print out constants referenced by the function 396 EmitConstantPool(); 397 398 // Print the 'header' of function. 399 const Function *F = MF->getFunction(); 400 401 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM)); 402 EmitVisibility(CurrentFnSym, F->getVisibility()); 403 404 EmitLinkage(F->getLinkage(), CurrentFnSym); 405 EmitAlignment(MF->getAlignment(), F); 406 407 if (MAI->hasDotTypeDotSizeDirective()) 408 OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction); 409 410 if (isVerbose()) { 411 WriteAsOperand(OutStreamer.GetCommentOS(), F, 412 /*PrintType=*/false, F->getParent()); 413 OutStreamer.GetCommentOS() << '\n'; 414 } 415 416 // Emit the CurrentFnSym. This is a virtual function to allow targets to 417 // do their wild and crazy things as required. 418 EmitFunctionEntryLabel(); 419 420 // If the function had address-taken blocks that got deleted, then we have 421 // references to the dangling symbols. Emit them at the start of the function 422 // so that we don't get references to undefined symbols. 423 std::vector<MCSymbol*> DeadBlockSyms; 424 MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms); 425 for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) { 426 OutStreamer.AddComment("Address taken block that was later removed"); 427 OutStreamer.EmitLabel(DeadBlockSyms[i]); 428 } 429 430 // Add some workaround for linkonce linkage on Cygwin\MinGW. 431 if (MAI->getLinkOnceDirective() != 0 && 432 (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) { 433 // FIXME: What is this? 434 MCSymbol *FakeStub = 435 OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+ 436 CurrentFnSym->getName()); 437 OutStreamer.EmitLabel(FakeStub); 438 } 439 440 // Emit pre-function debug and/or EH information. 441#ifndef ANDROID_TARGET_BUILD 442 if (DE) { 443 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 444 DE->BeginFunction(MF); 445 } 446 if (DD) { 447 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 448 DD->beginFunction(MF); 449 } 450#endif // ANDROID_TARGET_BUILD 451} 452 453/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the 454/// function. This can be overridden by targets as required to do custom stuff. 455void AsmPrinter::EmitFunctionEntryLabel() { 456 // The function label could have already been emitted if two symbols end up 457 // conflicting due to asm renaming. Detect this and emit an error. 458 if (CurrentFnSym->isUndefined()) 459 return OutStreamer.EmitLabel(CurrentFnSym); 460 461 report_fatal_error("'" + Twine(CurrentFnSym->getName()) + 462 "' label emitted multiple times to assembly file"); 463} 464 465 466static void EmitDebugLoc(DebugLoc DL, const MachineFunction *MF, 467 raw_ostream &CommentOS) { 468 const LLVMContext &Ctx = MF->getFunction()->getContext(); 469 if (!DL.isUnknown()) { // Print source line info. 470 DIScope Scope(DL.getScope(Ctx)); 471 // Omit the directory, because it's likely to be long and uninteresting. 472 if (Scope.Verify()) 473 CommentOS << Scope.getFilename(); 474 else 475 CommentOS << "<unknown>"; 476 CommentOS << ':' << DL.getLine(); 477 if (DL.getCol() != 0) 478 CommentOS << ':' << DL.getCol(); 479 DebugLoc InlinedAtDL = DebugLoc::getFromDILocation(DL.getInlinedAt(Ctx)); 480 if (!InlinedAtDL.isUnknown()) { 481 CommentOS << "[ "; 482 EmitDebugLoc(InlinedAtDL, MF, CommentOS); 483 CommentOS << " ]"; 484 } 485 } 486} 487 488/// EmitComments - Pretty-print comments for instructions. 489static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) { 490 const MachineFunction *MF = MI.getParent()->getParent(); 491 const TargetMachine &TM = MF->getTarget(); 492 493 DebugLoc DL = MI.getDebugLoc(); 494 if (!DL.isUnknown()) { // Print source line info. 495 EmitDebugLoc(DL, MF, CommentOS); 496 CommentOS << '\n'; 497 } 498 499 // Check for spills and reloads 500 int FI; 501 502 const MachineFrameInfo *FrameInfo = MF->getFrameInfo(); 503 504 // We assume a single instruction only has a spill or reload, not 505 // both. 506 const MachineMemOperand *MMO; 507 if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) { 508 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 509 MMO = *MI.memoperands_begin(); 510 CommentOS << MMO->getSize() << "-byte Reload\n"; 511 } 512 } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) { 513 if (FrameInfo->isSpillSlotObjectIndex(FI)) 514 CommentOS << MMO->getSize() << "-byte Folded Reload\n"; 515 } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) { 516 if (FrameInfo->isSpillSlotObjectIndex(FI)) { 517 MMO = *MI.memoperands_begin(); 518 CommentOS << MMO->getSize() << "-byte Spill\n"; 519 } 520 } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) { 521 if (FrameInfo->isSpillSlotObjectIndex(FI)) 522 CommentOS << MMO->getSize() << "-byte Folded Spill\n"; 523 } 524 525 // Check for spill-induced copies 526 if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse)) 527 CommentOS << " Reload Reuse\n"; 528} 529 530/// EmitImplicitDef - This method emits the specified machine instruction 531/// that is an implicit def. 532static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) { 533 unsigned RegNo = MI->getOperand(0).getReg(); 534 AP.OutStreamer.AddComment(Twine("implicit-def: ") + 535 AP.TM.getRegisterInfo()->getName(RegNo)); 536 AP.OutStreamer.AddBlankLine(); 537} 538 539static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) { 540 std::string Str = "kill:"; 541 for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { 542 const MachineOperand &Op = MI->getOperand(i); 543 assert(Op.isReg() && "KILL instruction must have only register operands"); 544 Str += ' '; 545 Str += AP.TM.getRegisterInfo()->getName(Op.getReg()); 546 Str += (Op.isDef() ? "<def>" : "<kill>"); 547 } 548 AP.OutStreamer.AddComment(Str); 549 AP.OutStreamer.AddBlankLine(); 550} 551 552/// EmitDebugValueComment - This method handles the target-independent form 553/// of DBG_VALUE, returning true if it was able to do so. A false return 554/// means the target will need to handle MI in EmitInstruction. 555static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) { 556 // This code handles only the 3-operand target-independent form. 557 if (MI->getNumOperands() != 3) 558 return false; 559 560 SmallString<128> Str; 561 raw_svector_ostream OS(Str); 562 OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: "; 563 564 // cast away const; DIetc do not take const operands for some reason. 565 DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata())); 566 if (V.getContext().isSubprogram()) 567 OS << DISubprogram(V.getContext()).getDisplayName() << ":"; 568 OS << V.getName() << " <- "; 569 570 // Register or immediate value. Register 0 means undef. 571 if (MI->getOperand(0).isFPImm()) { 572 APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF()); 573 if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) { 574 OS << (double)APF.convertToFloat(); 575 } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) { 576 OS << APF.convertToDouble(); 577 } else { 578 // There is no good way to print long double. Convert a copy to 579 // double. Ah well, it's only a comment. 580 bool ignored; 581 APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 582 &ignored); 583 OS << "(long double) " << APF.convertToDouble(); 584 } 585 } else if (MI->getOperand(0).isImm()) { 586 OS << MI->getOperand(0).getImm(); 587 } else { 588 assert(MI->getOperand(0).isReg() && "Unknown operand type"); 589 if (MI->getOperand(0).getReg() == 0) { 590 // Suppress offset, it is not meaningful here. 591 OS << "undef"; 592 // NOTE: Want this comment at start of line, don't emit with AddComment. 593 AP.OutStreamer.EmitRawText(OS.str()); 594 return true; 595 } 596 OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg()); 597 } 598 599 OS << '+' << MI->getOperand(1).getImm(); 600 // NOTE: Want this comment at start of line, don't emit with AddComment. 601 AP.OutStreamer.EmitRawText(OS.str()); 602 return true; 603} 604 605/// EmitFunctionBody - This method emits the body and trailer for a 606/// function. 607void AsmPrinter::EmitFunctionBody() { 608 // Emit target-specific gunk before the function body. 609 EmitFunctionBodyStart(); 610 611 bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo(); 612 613 // Print out code for the function. 614 bool HasAnyRealCode = false; 615 const MachineInstr *LastMI = 0; 616 for (MachineFunction::const_iterator I = MF->begin(), E = MF->end(); 617 I != E; ++I) { 618 // Print a label for the basic block. 619 EmitBasicBlockStart(I); 620 for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end(); 621 II != IE; ++II) { 622 LastMI = II; 623 624 // Print the assembly for the instruction. 625 if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() && 626 !II->isDebugValue()) { 627 HasAnyRealCode = true; 628 629 ++EmittedInsts; 630 } 631#ifndef ANDROID_TARGET_BUILD 632 if (ShouldPrintDebugScopes) { 633 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 634 DD->beginScope(II); 635 } 636#endif // ANDROID_TARGET_BUILD 637 638 if (isVerbose()) 639 EmitComments(*II, OutStreamer.GetCommentOS()); 640 641 switch (II->getOpcode()) { 642 case TargetOpcode::PROLOG_LABEL: 643 case TargetOpcode::EH_LABEL: 644 case TargetOpcode::GC_LABEL: 645 OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol()); 646 break; 647 case TargetOpcode::INLINEASM: 648 EmitInlineAsm(II); 649 break; 650 case TargetOpcode::DBG_VALUE: 651 if (isVerbose()) { 652 if (!EmitDebugValueComment(II, *this)) 653 EmitInstruction(II); 654 } 655 break; 656 case TargetOpcode::IMPLICIT_DEF: 657 if (isVerbose()) EmitImplicitDef(II, *this); 658 break; 659 case TargetOpcode::KILL: 660 if (isVerbose()) EmitKill(II, *this); 661 break; 662 default: 663 EmitInstruction(II); 664 break; 665 } 666 667#ifndef ANDROID_TARGET_BUILD 668 if (ShouldPrintDebugScopes) { 669 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 670 DD->endScope(II); 671 } 672#endif // ANDROID_TARGET_BUILD 673 } 674 } 675 676 // If the last instruction was a prolog label, then we have a situation where 677 // we emitted a prolog but no function body. This results in the ending prolog 678 // label equaling the end of function label and an invalid "row" in the 679 // FDE. We need to emit a noop in this situation so that the FDE's rows are 680 // valid. 681 bool RequiresNoop = LastMI && LastMI->isPrologLabel(); 682 683 // If the function is empty and the object file uses .subsections_via_symbols, 684 // then we need to emit *something* to the function body to prevent the 685 // labels from collapsing together. Just emit a noop. 686 if ((MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) || RequiresNoop) { 687 MCInst Noop; 688 TM.getInstrInfo()->getNoopForMachoTarget(Noop); 689 if (Noop.getOpcode()) { 690 OutStreamer.AddComment("avoids zero-length function"); 691 OutStreamer.EmitInstruction(Noop); 692 } else // Target not mc-ized yet. 693 OutStreamer.EmitRawText(StringRef("\tnop\n")); 694 } 695 696 // Emit target-specific gunk after the function body. 697 EmitFunctionBodyEnd(); 698 699 // If the target wants a .size directive for the size of the function, emit 700 // it. 701 if (MAI->hasDotTypeDotSizeDirective()) { 702 // Create a symbol for the end of function, so we can get the size as 703 // difference between the function label and the temp label. 704 MCSymbol *FnEndLabel = OutContext.CreateTempSymbol(); 705 OutStreamer.EmitLabel(FnEndLabel); 706 707 const MCExpr *SizeExp = 708 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext), 709 MCSymbolRefExpr::Create(CurrentFnSym, OutContext), 710 OutContext); 711 OutStreamer.EmitELFSize(CurrentFnSym, SizeExp); 712 } 713 714 // Emit post-function debug information. 715#ifndef ANDROID_TARGET_BUILD 716 if (DD) { 717 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 718 DD->endFunction(MF); 719 } 720 if (DE) { 721 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 722 DE->EndFunction(); 723 } 724#endif // ANDROID_TARGET_BUILD 725 MMI->EndFunction(); 726 727 // Print out jump tables referenced by the function. 728 EmitJumpTableInfo(); 729 730 OutStreamer.AddBlankLine(); 731} 732 733/// getDebugValueLocation - Get location information encoded by DBG_VALUE 734/// operands. 735MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const { 736 // Target specific DBG_VALUE instructions are handled by each target. 737 return MachineLocation(); 738} 739 740bool AsmPrinter::doFinalization(Module &M) { 741 // Emit global variables. 742 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 743 I != E; ++I) 744 EmitGlobalVariable(I); 745 746 // Finalize debug and EH information. 747#ifndef ANDROID_TARGET_BUILD 748 if (DE) { 749 { 750 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 751 DE->EndModule(); 752 } 753 delete DE; DE = 0; 754 } 755 if (DD) { 756 { 757 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 758 DD->endModule(); 759 } 760 delete DD; DD = 0; 761 } 762#endif // ANDROID_TARGET_BUILD 763 764 // If the target wants to know about weak references, print them all. 765 if (MAI->getWeakRefDirective()) { 766 // FIXME: This is not lazy, it would be nice to only print weak references 767 // to stuff that is actually used. Note that doing so would require targets 768 // to notice uses in operands (due to constant exprs etc). This should 769 // happen with the MC stuff eventually. 770 771 // Print out module-level global variables here. 772 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 773 I != E; ++I) { 774 if (!I->hasExternalWeakLinkage()) continue; 775 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 776 } 777 778 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 779 if (!I->hasExternalWeakLinkage()) continue; 780 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 781 } 782 } 783 784 if (MAI->hasSetDirective()) { 785 OutStreamer.AddBlankLine(); 786 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 787 I != E; ++I) { 788 MCSymbol *Name = Mang->getSymbol(I); 789 790 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 791 MCSymbol *Target = Mang->getSymbol(GV); 792 793 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 794 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 795 else if (I->hasWeakLinkage()) 796 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 797 else 798 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 799 800 EmitVisibility(Name, I->getVisibility()); 801 802 // Emit the directives as assignments aka .set: 803 OutStreamer.EmitAssignment(Name, 804 MCSymbolRefExpr::Create(Target, OutContext)); 805 } 806 } 807 808 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 809 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 810 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 811 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 812 MP->finishAssembly(*this); 813 814 // If we don't have any trampolines, then we don't require stack memory 815 // to be executable. Some targets have a directive to declare this. 816 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 817 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 818 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 819 OutStreamer.SwitchSection(S); 820 821 // Allow the target to emit any magic that it wants at the end of the file, 822 // after everything else has gone out. 823 EmitEndOfAsmFile(M); 824 825 delete Mang; Mang = 0; 826 MMI = 0; 827 828 OutStreamer.Finish(); 829 return false; 830} 831 832void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 833 this->MF = &MF; 834 // Get the function symbol. 835 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 836 837 if (isVerbose()) 838 LI = &getAnalysis<MachineLoopInfo>(); 839} 840 841namespace { 842 // SectionCPs - Keep track the alignment, constpool entries per Section. 843 struct SectionCPs { 844 const MCSection *S; 845 unsigned Alignment; 846 SmallVector<unsigned, 4> CPEs; 847 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 848 }; 849} 850 851/// EmitConstantPool - Print to the current output stream assembly 852/// representations of the constants in the constant pool MCP. This is 853/// used to print out constants which have been "spilled to memory" by 854/// the code generator. 855/// 856void AsmPrinter::EmitConstantPool() { 857 const MachineConstantPool *MCP = MF->getConstantPool(); 858 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 859 if (CP.empty()) return; 860 861 // Calculate sections for constant pool entries. We collect entries to go into 862 // the same section together to reduce amount of section switch statements. 863 SmallVector<SectionCPs, 4> CPSections; 864 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 865 const MachineConstantPoolEntry &CPE = CP[i]; 866 unsigned Align = CPE.getAlignment(); 867 868 SectionKind Kind; 869 switch (CPE.getRelocationInfo()) { 870 default: llvm_unreachable("Unknown section kind"); 871 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 872 case 1: 873 Kind = SectionKind::getReadOnlyWithRelLocal(); 874 break; 875 case 0: 876 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 877 case 4: Kind = SectionKind::getMergeableConst4(); break; 878 case 8: Kind = SectionKind::getMergeableConst8(); break; 879 case 16: Kind = SectionKind::getMergeableConst16();break; 880 default: Kind = SectionKind::getMergeableConst(); break; 881 } 882 } 883 884 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 885 886 // The number of sections are small, just do a linear search from the 887 // last section to the first. 888 bool Found = false; 889 unsigned SecIdx = CPSections.size(); 890 while (SecIdx != 0) { 891 if (CPSections[--SecIdx].S == S) { 892 Found = true; 893 break; 894 } 895 } 896 if (!Found) { 897 SecIdx = CPSections.size(); 898 CPSections.push_back(SectionCPs(S, Align)); 899 } 900 901 if (Align > CPSections[SecIdx].Alignment) 902 CPSections[SecIdx].Alignment = Align; 903 CPSections[SecIdx].CPEs.push_back(i); 904 } 905 906 // Now print stuff into the calculated sections. 907 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 908 OutStreamer.SwitchSection(CPSections[i].S); 909 EmitAlignment(Log2_32(CPSections[i].Alignment)); 910 911 unsigned Offset = 0; 912 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 913 unsigned CPI = CPSections[i].CPEs[j]; 914 MachineConstantPoolEntry CPE = CP[CPI]; 915 916 // Emit inter-object padding for alignment. 917 unsigned AlignMask = CPE.getAlignment() - 1; 918 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 919 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 920 921 const Type *Ty = CPE.getType(); 922 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 923 924 // Emit the label with a comment on it. 925 if (isVerbose()) { 926 OutStreamer.GetCommentOS() << "constant pool "; 927 WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(), 928 MF->getFunction()->getParent()); 929 OutStreamer.GetCommentOS() << '\n'; 930 } 931 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 932 933 if (CPE.isMachineConstantPoolEntry()) 934 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 935 else 936 EmitGlobalConstant(CPE.Val.ConstVal); 937 } 938 } 939} 940 941/// EmitJumpTableInfo - Print assembly representations of the jump tables used 942/// by the current function to the current output stream. 943/// 944void AsmPrinter::EmitJumpTableInfo() { 945 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 946 if (MJTI == 0) return; 947 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 948 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 949 if (JT.empty()) return; 950 951 // Pick the directive to use to print the jump table entries, and switch to 952 // the appropriate section. 953 const Function *F = MF->getFunction(); 954 bool JTInDiffSection = false; 955 if (// In PIC mode, we need to emit the jump table to the same section as the 956 // function body itself, otherwise the label differences won't make sense. 957 // FIXME: Need a better predicate for this: what about custom entries? 958 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 959 // We should also do if the section name is NULL or function is declared 960 // in discardable section 961 // FIXME: this isn't the right predicate, should be based on the MCSection 962 // for the function. 963 F->isWeakForLinker()) { 964 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 965 } else { 966 // Otherwise, drop it in the readonly section. 967 const MCSection *ReadOnlySection = 968 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 969 OutStreamer.SwitchSection(ReadOnlySection); 970 JTInDiffSection = true; 971 } 972 973 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 974 975 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 976 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 977 978 // If this jump table was deleted, ignore it. 979 if (JTBBs.empty()) continue; 980 981 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 982 // .set directive for each unique entry. This reduces the number of 983 // relocations the assembler will generate for the jump table. 984 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 985 MAI->hasSetDirective()) { 986 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 987 const TargetLowering *TLI = TM.getTargetLowering(); 988 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 989 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 990 const MachineBasicBlock *MBB = JTBBs[ii]; 991 if (!EmittedSets.insert(MBB)) continue; 992 993 // .set LJTSet, LBB32-base 994 const MCExpr *LHS = 995 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 996 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 997 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 998 } 999 } 1000 1001 // On some targets (e.g. Darwin) we want to emit two consequtive labels 1002 // before each jump table. The first label is never referenced, but tells 1003 // the assembler and linker the extents of the jump table object. The 1004 // second label is actually referenced by the code. 1005 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1006 // FIXME: This doesn't have to have any specific name, just any randomly 1007 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1008 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1009 1010 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1011 1012 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1013 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1014 } 1015} 1016 1017/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1018/// current stream. 1019void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1020 const MachineBasicBlock *MBB, 1021 unsigned UID) const { 1022 const MCExpr *Value = 0; 1023 switch (MJTI->getEntryKind()) { 1024 case MachineJumpTableInfo::EK_Inline: 1025 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1026 case MachineJumpTableInfo::EK_Custom32: 1027 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1028 OutContext); 1029 break; 1030 case MachineJumpTableInfo::EK_BlockAddress: 1031 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1032 // .word LBB123 1033 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1034 break; 1035 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1036 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1037 // with a relocation as gp-relative, e.g.: 1038 // .gprel32 LBB123 1039 MCSymbol *MBBSym = MBB->getSymbol(); 1040 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1041 return; 1042 } 1043 1044 case MachineJumpTableInfo::EK_LabelDifference32: { 1045 // EK_LabelDifference32 - Each entry is the address of the block minus 1046 // the address of the jump table. This is used for PIC jump tables where 1047 // gprel32 is not supported. e.g.: 1048 // .word LBB123 - LJTI1_2 1049 // If the .set directive is supported, this is emitted as: 1050 // .set L4_5_set_123, LBB123 - LJTI1_2 1051 // .word L4_5_set_123 1052 1053 // If we have emitted set directives for the jump table entries, print 1054 // them rather than the entries themselves. If we're emitting PIC, then 1055 // emit the table entries as differences between two text section labels. 1056 if (MAI->hasSetDirective()) { 1057 // If we used .set, reference the .set's symbol. 1058 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1059 OutContext); 1060 break; 1061 } 1062 // Otherwise, use the difference as the jump table entry. 1063 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1064 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1065 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1066 break; 1067 } 1068 } 1069 1070 assert(Value && "Unknown entry kind!"); 1071 1072 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1073 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1074} 1075 1076 1077/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1078/// special global used by LLVM. If so, emit it and return true, otherwise 1079/// do nothing and return false. 1080bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1081 if (GV->getName() == "llvm.used") { 1082 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1083 EmitLLVMUsedList(GV->getInitializer()); 1084 return true; 1085 } 1086 1087 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1088 if (GV->getSection() == "llvm.metadata" || 1089 GV->hasAvailableExternallyLinkage()) 1090 return true; 1091 1092 if (!GV->hasAppendingLinkage()) return false; 1093 1094 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1095 1096 const TargetData *TD = TM.getTargetData(); 1097 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1098 if (GV->getName() == "llvm.global_ctors") { 1099 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1100 EmitAlignment(Align); 1101 EmitXXStructorList(GV->getInitializer()); 1102 1103 if (TM.getRelocationModel() == Reloc::Static && 1104 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1105 StringRef Sym(".constructors_used"); 1106 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1107 MCSA_Reference); 1108 } 1109 return true; 1110 } 1111 1112 if (GV->getName() == "llvm.global_dtors") { 1113 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1114 EmitAlignment(Align); 1115 EmitXXStructorList(GV->getInitializer()); 1116 1117 if (TM.getRelocationModel() == Reloc::Static && 1118 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1119 StringRef Sym(".destructors_used"); 1120 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1121 MCSA_Reference); 1122 } 1123 return true; 1124 } 1125 1126 return false; 1127} 1128 1129/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1130/// global in the specified llvm.used list for which emitUsedDirectiveFor 1131/// is true, as being used with this directive. 1132void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1133 // Should be an array of 'i8*'. 1134 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1135 if (InitList == 0) return; 1136 1137 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1138 const GlobalValue *GV = 1139 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1140 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1141 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1142 } 1143} 1144 1145/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1146/// function pointers, ignoring the init priority. 1147void AsmPrinter::EmitXXStructorList(Constant *List) { 1148 // Should be an array of '{ int, void ()* }' structs. The first value is the 1149 // init priority, which we ignore. 1150 if (!isa<ConstantArray>(List)) return; 1151 ConstantArray *InitList = cast<ConstantArray>(List); 1152 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1153 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1154 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1155 1156 if (CS->getOperand(1)->isNullValue()) 1157 return; // Found a null terminator, exit printing. 1158 // Emit the function pointer. 1159 EmitGlobalConstant(CS->getOperand(1)); 1160 } 1161} 1162 1163//===--------------------------------------------------------------------===// 1164// Emission and print routines 1165// 1166 1167/// EmitInt8 - Emit a byte directive and value. 1168/// 1169void AsmPrinter::EmitInt8(int Value) const { 1170 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1171} 1172 1173/// EmitInt16 - Emit a short directive and value. 1174/// 1175void AsmPrinter::EmitInt16(int Value) const { 1176 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1177} 1178 1179/// EmitInt32 - Emit a long directive and value. 1180/// 1181void AsmPrinter::EmitInt32(int Value) const { 1182 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1183} 1184 1185/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1186/// in bytes of the directive is specified by Size and Hi/Lo specify the 1187/// labels. This implicitly uses .set if it is available. 1188void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1189 unsigned Size) const { 1190 // Get the Hi-Lo expression. 1191 const MCExpr *Diff = 1192 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1193 MCSymbolRefExpr::Create(Lo, OutContext), 1194 OutContext); 1195 1196 if (!MAI->hasSetDirective()) { 1197 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1198 return; 1199 } 1200 1201 // Otherwise, emit with .set (aka assignment). 1202 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1203 OutStreamer.EmitAssignment(SetLabel, Diff); 1204 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1205} 1206 1207/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1208/// where the size in bytes of the directive is specified by Size and Hi/Lo 1209/// specify the labels. This implicitly uses .set if it is available. 1210void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1211 const MCSymbol *Lo, unsigned Size) 1212 const { 1213 1214 // Emit Hi+Offset - Lo 1215 // Get the Hi+Offset expression. 1216 const MCExpr *Plus = 1217 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1218 MCConstantExpr::Create(Offset, OutContext), 1219 OutContext); 1220 1221 // Get the Hi+Offset-Lo expression. 1222 const MCExpr *Diff = 1223 MCBinaryExpr::CreateSub(Plus, 1224 MCSymbolRefExpr::Create(Lo, OutContext), 1225 OutContext); 1226 1227 if (!MAI->hasSetDirective()) 1228 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1229 else { 1230 // Otherwise, emit with .set (aka assignment). 1231 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1232 OutStreamer.EmitAssignment(SetLabel, Diff); 1233 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1234 } 1235} 1236 1237 1238//===----------------------------------------------------------------------===// 1239 1240// EmitAlignment - Emit an alignment directive to the specified power of 1241// two boundary. For example, if you pass in 3 here, you will get an 8 1242// byte alignment. If a global value is specified, and if that global has 1243// an explicit alignment requested, it will override the alignment request 1244// if required for correctness. 1245// 1246void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1247 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1248 1249 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1250 1251 if (getCurrentSection()->getKind().isText()) 1252 OutStreamer.EmitCodeAlignment(1 << NumBits); 1253 else 1254 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1255} 1256 1257//===----------------------------------------------------------------------===// 1258// Constant emission. 1259//===----------------------------------------------------------------------===// 1260 1261/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1262/// 1263static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1264 MCContext &Ctx = AP.OutContext; 1265 1266 if (CV->isNullValue() || isa<UndefValue>(CV)) 1267 return MCConstantExpr::Create(0, Ctx); 1268 1269 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1270 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1271 1272 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1273 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1274 1275 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1276 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1277 1278 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1279 if (CE == 0) { 1280 llvm_unreachable("Unknown constant value to lower!"); 1281 return MCConstantExpr::Create(0, Ctx); 1282 } 1283 1284 switch (CE->getOpcode()) { 1285 default: 1286 // If the code isn't optimized, there may be outstanding folding 1287 // opportunities. Attempt to fold the expression using TargetData as a 1288 // last resort before giving up. 1289 if (Constant *C = 1290 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1291 if (C != CE) 1292 return LowerConstant(C, AP); 1293 1294 // Otherwise report the problem to the user. 1295 { 1296 std::string S; 1297 raw_string_ostream OS(S); 1298 OS << "Unsupported expression in static initializer: "; 1299 WriteAsOperand(OS, CE, /*PrintType=*/false, 1300 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1301 report_fatal_error(OS.str()); 1302 } 1303 return MCConstantExpr::Create(0, Ctx); 1304 case Instruction::GetElementPtr: { 1305 const TargetData &TD = *AP.TM.getTargetData(); 1306 // Generate a symbolic expression for the byte address 1307 const Constant *PtrVal = CE->getOperand(0); 1308 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1309 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1310 IdxVec.size()); 1311 1312 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1313 if (Offset == 0) 1314 return Base; 1315 1316 // Truncate/sext the offset to the pointer size. 1317 if (TD.getPointerSizeInBits() != 64) { 1318 int SExtAmount = 64-TD.getPointerSizeInBits(); 1319 Offset = (Offset << SExtAmount) >> SExtAmount; 1320 } 1321 1322 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1323 Ctx); 1324 } 1325 1326 case Instruction::Trunc: 1327 // We emit the value and depend on the assembler to truncate the generated 1328 // expression properly. This is important for differences between 1329 // blockaddress labels. Since the two labels are in the same function, it 1330 // is reasonable to treat their delta as a 32-bit value. 1331 // FALL THROUGH. 1332 case Instruction::BitCast: 1333 return LowerConstant(CE->getOperand(0), AP); 1334 1335 case Instruction::IntToPtr: { 1336 const TargetData &TD = *AP.TM.getTargetData(); 1337 // Handle casts to pointers by changing them into casts to the appropriate 1338 // integer type. This promotes constant folding and simplifies this code. 1339 Constant *Op = CE->getOperand(0); 1340 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1341 false/*ZExt*/); 1342 return LowerConstant(Op, AP); 1343 } 1344 1345 case Instruction::PtrToInt: { 1346 const TargetData &TD = *AP.TM.getTargetData(); 1347 // Support only foldable casts to/from pointers that can be eliminated by 1348 // changing the pointer to the appropriately sized integer type. 1349 Constant *Op = CE->getOperand(0); 1350 const Type *Ty = CE->getType(); 1351 1352 const MCExpr *OpExpr = LowerConstant(Op, AP); 1353 1354 // We can emit the pointer value into this slot if the slot is an 1355 // integer slot equal to the size of the pointer. 1356 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1357 return OpExpr; 1358 1359 // Otherwise the pointer is smaller than the resultant integer, mask off 1360 // the high bits so we are sure to get a proper truncation if the input is 1361 // a constant expr. 1362 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1363 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1364 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1365 } 1366 1367 // The MC library also has a right-shift operator, but it isn't consistently 1368 // signed or unsigned between different targets. 1369 case Instruction::Add: 1370 case Instruction::Sub: 1371 case Instruction::Mul: 1372 case Instruction::SDiv: 1373 case Instruction::SRem: 1374 case Instruction::Shl: 1375 case Instruction::And: 1376 case Instruction::Or: 1377 case Instruction::Xor: { 1378 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1379 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1380 switch (CE->getOpcode()) { 1381 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1382 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1383 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1384 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1385 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1386 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1387 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1388 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1389 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1390 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1391 } 1392 } 1393 } 1394} 1395 1396static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1397 AsmPrinter &AP); 1398 1399static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1400 AsmPrinter &AP) { 1401 if (AddrSpace != 0 || !CA->isString()) { 1402 // Not a string. Print the values in successive locations 1403 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1404 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1405 return; 1406 } 1407 1408 // Otherwise, it can be emitted as .ascii. 1409 SmallVector<char, 128> TmpVec; 1410 TmpVec.reserve(CA->getNumOperands()); 1411 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1412 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1413 1414 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1415} 1416 1417static void EmitGlobalConstantVector(const ConstantVector *CV, 1418 unsigned AddrSpace, AsmPrinter &AP) { 1419 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1420 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1421} 1422 1423static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1424 unsigned AddrSpace, AsmPrinter &AP) { 1425 // Print the fields in successive locations. Pad to align if needed! 1426 const TargetData *TD = AP.TM.getTargetData(); 1427 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1428 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1429 uint64_t SizeSoFar = 0; 1430 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1431 const Constant *Field = CS->getOperand(i); 1432 1433 // Check if padding is needed and insert one or more 0s. 1434 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1435 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1436 - Layout->getElementOffset(i)) - FieldSize; 1437 SizeSoFar += FieldSize + PadSize; 1438 1439 // Now print the actual field value. 1440 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1441 1442 // Insert padding - this may include padding to increase the size of the 1443 // current field up to the ABI size (if the struct is not packed) as well 1444 // as padding to ensure that the next field starts at the right offset. 1445 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1446 } 1447 assert(SizeSoFar == Layout->getSizeInBytes() && 1448 "Layout of constant struct may be incorrect!"); 1449} 1450 1451static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1452 AsmPrinter &AP) { 1453 // FP Constants are printed as integer constants to avoid losing 1454 // precision. 1455 if (CFP->getType()->isDoubleTy()) { 1456 if (AP.isVerbose()) { 1457 double Val = CFP->getValueAPF().convertToDouble(); 1458 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1459 } 1460 1461 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1462 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1463 return; 1464 } 1465 1466 if (CFP->getType()->isFloatTy()) { 1467 if (AP.isVerbose()) { 1468 float Val = CFP->getValueAPF().convertToFloat(); 1469 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1470 } 1471 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1472 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1473 return; 1474 } 1475 1476 if (CFP->getType()->isX86_FP80Ty()) { 1477 // all long double variants are printed as hex 1478 // API needed to prevent premature destruction 1479 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1480 const uint64_t *p = API.getRawData(); 1481 if (AP.isVerbose()) { 1482 // Convert to double so we can print the approximate val as a comment. 1483 APFloat DoubleVal = CFP->getValueAPF(); 1484 bool ignored; 1485 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1486 &ignored); 1487 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1488 << DoubleVal.convertToDouble() << '\n'; 1489 } 1490 1491 if (AP.TM.getTargetData()->isBigEndian()) { 1492 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1493 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1494 } else { 1495 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1496 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1497 } 1498 1499 // Emit the tail padding for the long double. 1500 const TargetData &TD = *AP.TM.getTargetData(); 1501 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1502 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1503 return; 1504 } 1505 1506 assert(CFP->getType()->isPPC_FP128Ty() && 1507 "Floating point constant type not handled"); 1508 // All long double variants are printed as hex 1509 // API needed to prevent premature destruction. 1510 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1511 const uint64_t *p = API.getRawData(); 1512 if (AP.TM.getTargetData()->isBigEndian()) { 1513 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1514 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1515 } else { 1516 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1517 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1518 } 1519} 1520 1521static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1522 unsigned AddrSpace, AsmPrinter &AP) { 1523 const TargetData *TD = AP.TM.getTargetData(); 1524 unsigned BitWidth = CI->getBitWidth(); 1525 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1526 1527 // We don't expect assemblers to support integer data directives 1528 // for more than 64 bits, so we emit the data in at most 64-bit 1529 // quantities at a time. 1530 const uint64_t *RawData = CI->getValue().getRawData(); 1531 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1532 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1533 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1534 } 1535} 1536 1537static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1538 AsmPrinter &AP) { 1539 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1540 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1541 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1542 } 1543 1544 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1545 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1546 switch (Size) { 1547 case 1: 1548 case 2: 1549 case 4: 1550 case 8: 1551 if (AP.isVerbose()) 1552 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1553 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1554 return; 1555 default: 1556 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1557 return; 1558 } 1559 } 1560 1561 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1562 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1563 1564 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1565 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1566 1567 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1568 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1569 1570 if (isa<ConstantPointerNull>(CV)) { 1571 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1572 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1573 return; 1574 } 1575 1576 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1577 return EmitGlobalConstantVector(V, AddrSpace, AP); 1578 1579 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1580 // thread the streamer with EmitValue. 1581 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1582 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1583 AddrSpace); 1584} 1585 1586/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1587void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1588 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1589 if (Size) 1590 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1591 else if (MAI->hasSubsectionsViaSymbols()) { 1592 // If the global has zero size, emit a single byte so that two labels don't 1593 // look like they are at the same location. 1594 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1595 } 1596} 1597 1598void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1599 // Target doesn't support this yet! 1600 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1601} 1602 1603void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1604 if (Offset > 0) 1605 OS << '+' << Offset; 1606 else if (Offset < 0) 1607 OS << Offset; 1608} 1609 1610//===----------------------------------------------------------------------===// 1611// Symbol Lowering Routines. 1612//===----------------------------------------------------------------------===// 1613 1614/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1615/// temporary label with the specified stem and unique ID. 1616MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1617 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1618 Name + Twine(ID)); 1619} 1620 1621/// GetTempSymbol - Return an assembler temporary label with the specified 1622/// stem. 1623MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1624 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1625 Name); 1626} 1627 1628 1629MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1630 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1631} 1632 1633MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1634 return MMI->getAddrLabelSymbol(BB); 1635} 1636 1637/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1638MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1639 return OutContext.GetOrCreateSymbol 1640 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1641 + "_" + Twine(CPID)); 1642} 1643 1644/// GetJTISymbol - Return the symbol for the specified jump table entry. 1645MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1646 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1647} 1648 1649/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1650/// FIXME: privatize to AsmPrinter. 1651MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1652 return OutContext.GetOrCreateSymbol 1653 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1654 Twine(UID) + "_set_" + Twine(MBBID)); 1655} 1656 1657/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1658/// global value name as its base, with the specified suffix, and where the 1659/// symbol is forced to have private linkage if ForcePrivate is true. 1660MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1661 StringRef Suffix, 1662 bool ForcePrivate) const { 1663 SmallString<60> NameStr; 1664 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1665 NameStr.append(Suffix.begin(), Suffix.end()); 1666 return OutContext.GetOrCreateSymbol(NameStr.str()); 1667} 1668 1669/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1670/// ExternalSymbol. 1671MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1672 SmallString<60> NameStr; 1673 Mang->getNameWithPrefix(NameStr, Sym); 1674 return OutContext.GetOrCreateSymbol(NameStr.str()); 1675} 1676 1677 1678 1679/// PrintParentLoopComment - Print comments about parent loops of this one. 1680static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1681 unsigned FunctionNumber) { 1682 if (Loop == 0) return; 1683 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1684 OS.indent(Loop->getLoopDepth()*2) 1685 << "Parent Loop BB" << FunctionNumber << "_" 1686 << Loop->getHeader()->getNumber() 1687 << " Depth=" << Loop->getLoopDepth() << '\n'; 1688} 1689 1690 1691/// PrintChildLoopComment - Print comments about child loops within 1692/// the loop for this basic block, with nesting. 1693static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1694 unsigned FunctionNumber) { 1695 // Add child loop information 1696 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1697 OS.indent((*CL)->getLoopDepth()*2) 1698 << "Child Loop BB" << FunctionNumber << "_" 1699 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1700 << '\n'; 1701 PrintChildLoopComment(OS, *CL, FunctionNumber); 1702 } 1703} 1704 1705/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1706static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1707 const MachineLoopInfo *LI, 1708 const AsmPrinter &AP) { 1709 // Add loop depth information 1710 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1711 if (Loop == 0) return; 1712 1713 MachineBasicBlock *Header = Loop->getHeader(); 1714 assert(Header && "No header for loop"); 1715 1716 // If this block is not a loop header, just print out what is the loop header 1717 // and return. 1718 if (Header != &MBB) { 1719 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1720 Twine(AP.getFunctionNumber())+"_" + 1721 Twine(Loop->getHeader()->getNumber())+ 1722 " Depth="+Twine(Loop->getLoopDepth())); 1723 return; 1724 } 1725 1726 // Otherwise, it is a loop header. Print out information about child and 1727 // parent loops. 1728 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1729 1730 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1731 1732 OS << "=>"; 1733 OS.indent(Loop->getLoopDepth()*2-2); 1734 1735 OS << "This "; 1736 if (Loop->empty()) 1737 OS << "Inner "; 1738 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1739 1740 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1741} 1742 1743 1744/// EmitBasicBlockStart - This method prints the label for the specified 1745/// MachineBasicBlock, an alignment (if present) and a comment describing 1746/// it if appropriate. 1747void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1748 // Emit an alignment directive for this block, if needed. 1749 if (unsigned Align = MBB->getAlignment()) 1750 EmitAlignment(Log2_32(Align)); 1751 1752 // If the block has its address taken, emit any labels that were used to 1753 // reference the block. It is possible that there is more than one label 1754 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1755 // the references were generated. 1756 if (MBB->hasAddressTaken()) { 1757 const BasicBlock *BB = MBB->getBasicBlock(); 1758 if (isVerbose()) 1759 OutStreamer.AddComment("Block address taken"); 1760 1761 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1762 1763 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1764 OutStreamer.EmitLabel(Syms[i]); 1765 } 1766 1767 // Print the main label for the block. 1768 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1769 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1770 if (const BasicBlock *BB = MBB->getBasicBlock()) 1771 if (BB->hasName()) 1772 OutStreamer.AddComment("%" + BB->getName()); 1773 1774 EmitBasicBlockLoopComments(*MBB, LI, *this); 1775 1776 // NOTE: Want this comment at start of line, don't emit with AddComment. 1777 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1778 Twine(MBB->getNumber()) + ":"); 1779 } 1780 } else { 1781 if (isVerbose()) { 1782 if (const BasicBlock *BB = MBB->getBasicBlock()) 1783 if (BB->hasName()) 1784 OutStreamer.AddComment("%" + BB->getName()); 1785 EmitBasicBlockLoopComments(*MBB, LI, *this); 1786 } 1787 1788 OutStreamer.EmitLabel(MBB->getSymbol()); 1789 } 1790} 1791 1792void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1793 MCSymbolAttr Attr = MCSA_Invalid; 1794 1795 switch (Visibility) { 1796 default: break; 1797 case GlobalValue::HiddenVisibility: 1798 Attr = MAI->getHiddenVisibilityAttr(); 1799 break; 1800 case GlobalValue::ProtectedVisibility: 1801 Attr = MAI->getProtectedVisibilityAttr(); 1802 break; 1803 } 1804 1805 if (Attr != MCSA_Invalid) 1806 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1807} 1808 1809/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1810/// exactly one predecessor and the control transfer mechanism between 1811/// the predecessor and this block is a fall-through. 1812bool AsmPrinter:: 1813isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1814 // If this is a landing pad, it isn't a fall through. If it has no preds, 1815 // then nothing falls through to it. 1816 if (MBB->isLandingPad() || MBB->pred_empty()) 1817 return false; 1818 1819 // If there isn't exactly one predecessor, it can't be a fall through. 1820 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1821 ++PI2; 1822 if (PI2 != MBB->pred_end()) 1823 return false; 1824 1825 // The predecessor has to be immediately before this block. 1826 const MachineBasicBlock *Pred = *PI; 1827 1828 if (!Pred->isLayoutSuccessor(MBB)) 1829 return false; 1830 1831 // If the block is completely empty, then it definitely does fall through. 1832 if (Pred->empty()) 1833 return true; 1834 1835 // Otherwise, check the last instruction. 1836 const MachineInstr &LastInst = Pred->back(); 1837 return !LastInst.getDesc().isBarrier(); 1838} 1839 1840 1841 1842GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1843 if (!S->usesMetadata()) 1844 return 0; 1845 1846 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1847 gcp_map_type::iterator GCPI = GCMap.find(S); 1848 if (GCPI != GCMap.end()) 1849 return GCPI->second; 1850 1851 const char *Name = S->getName().c_str(); 1852 1853 for (GCMetadataPrinterRegistry::iterator 1854 I = GCMetadataPrinterRegistry::begin(), 1855 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1856 if (strcmp(Name, I->getName()) == 0) { 1857 GCMetadataPrinter *GMP = I->instantiate(); 1858 GMP->S = S; 1859 GCMap.insert(std::make_pair(S, GMP)); 1860 return GMP; 1861 } 1862 1863 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1864 return 0; 1865} 1866 1867