AsmPrinter.cpp revision 218893
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 // Emit visibility info for declarations 758 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 759 const Function &F = *I; 760 if (!F.isDeclaration()) 761 continue; 762 GlobalValue::VisibilityTypes V = F.getVisibility(); 763 if (V == GlobalValue::DefaultVisibility) 764 continue; 765 766 MCSymbol *Name = Mang->getSymbol(&F); 767 EmitVisibility(Name, V); 768 } 769 770 // Finalize debug and EH information. 771 if (DE) { 772 { 773 NamedRegionTimer T(EHTimerName, DWARFGroupName, TimePassesIsEnabled); 774 DE->EndModule(); 775 } 776 delete DE; DE = 0; 777 } 778 if (DD) { 779 { 780 NamedRegionTimer T(DbgTimerName, DWARFGroupName, TimePassesIsEnabled); 781 DD->endModule(); 782 } 783 delete DD; DD = 0; 784 } 785 786 // If the target wants to know about weak references, print them all. 787 if (MAI->getWeakRefDirective()) { 788 // FIXME: This is not lazy, it would be nice to only print weak references 789 // to stuff that is actually used. Note that doing so would require targets 790 // to notice uses in operands (due to constant exprs etc). This should 791 // happen with the MC stuff eventually. 792 793 // Print out module-level global variables here. 794 for (Module::const_global_iterator I = M.global_begin(), E = M.global_end(); 795 I != E; ++I) { 796 if (!I->hasExternalWeakLinkage()) continue; 797 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 798 } 799 800 for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 801 if (!I->hasExternalWeakLinkage()) continue; 802 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference); 803 } 804 } 805 806 if (MAI->hasSetDirective()) { 807 OutStreamer.AddBlankLine(); 808 for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end(); 809 I != E; ++I) { 810 MCSymbol *Name = Mang->getSymbol(I); 811 812 const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal()); 813 MCSymbol *Target = Mang->getSymbol(GV); 814 815 if (I->hasExternalLinkage() || !MAI->getWeakRefDirective()) 816 OutStreamer.EmitSymbolAttribute(Name, MCSA_Global); 817 else if (I->hasWeakLinkage()) 818 OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference); 819 else 820 assert(I->hasLocalLinkage() && "Invalid alias linkage"); 821 822 EmitVisibility(Name, I->getVisibility()); 823 824 // Emit the directives as assignments aka .set: 825 OutStreamer.EmitAssignment(Name, 826 MCSymbolRefExpr::Create(Target, OutContext)); 827 } 828 } 829 830 GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>(); 831 assert(MI && "AsmPrinter didn't require GCModuleInfo?"); 832 for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; ) 833 if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I)) 834 MP->finishAssembly(*this); 835 836 // If we don't have any trampolines, then we don't require stack memory 837 // to be executable. Some targets have a directive to declare this. 838 Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline"); 839 if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty()) 840 if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext)) 841 OutStreamer.SwitchSection(S); 842 843 // Allow the target to emit any magic that it wants at the end of the file, 844 // after everything else has gone out. 845 EmitEndOfAsmFile(M); 846 847 delete Mang; Mang = 0; 848 MMI = 0; 849 850 OutStreamer.Finish(); 851 return false; 852} 853 854void AsmPrinter::SetupMachineFunction(MachineFunction &MF) { 855 this->MF = &MF; 856 // Get the function symbol. 857 CurrentFnSym = Mang->getSymbol(MF.getFunction()); 858 859 if (isVerbose()) 860 LI = &getAnalysis<MachineLoopInfo>(); 861} 862 863namespace { 864 // SectionCPs - Keep track the alignment, constpool entries per Section. 865 struct SectionCPs { 866 const MCSection *S; 867 unsigned Alignment; 868 SmallVector<unsigned, 4> CPEs; 869 SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {} 870 }; 871} 872 873/// EmitConstantPool - Print to the current output stream assembly 874/// representations of the constants in the constant pool MCP. This is 875/// used to print out constants which have been "spilled to memory" by 876/// the code generator. 877/// 878void AsmPrinter::EmitConstantPool() { 879 const MachineConstantPool *MCP = MF->getConstantPool(); 880 const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants(); 881 if (CP.empty()) return; 882 883 // Calculate sections for constant pool entries. We collect entries to go into 884 // the same section together to reduce amount of section switch statements. 885 SmallVector<SectionCPs, 4> CPSections; 886 for (unsigned i = 0, e = CP.size(); i != e; ++i) { 887 const MachineConstantPoolEntry &CPE = CP[i]; 888 unsigned Align = CPE.getAlignment(); 889 890 SectionKind Kind; 891 switch (CPE.getRelocationInfo()) { 892 default: llvm_unreachable("Unknown section kind"); 893 case 2: Kind = SectionKind::getReadOnlyWithRel(); break; 894 case 1: 895 Kind = SectionKind::getReadOnlyWithRelLocal(); 896 break; 897 case 0: 898 switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) { 899 case 4: Kind = SectionKind::getMergeableConst4(); break; 900 case 8: Kind = SectionKind::getMergeableConst8(); break; 901 case 16: Kind = SectionKind::getMergeableConst16();break; 902 default: Kind = SectionKind::getMergeableConst(); break; 903 } 904 } 905 906 const MCSection *S = getObjFileLowering().getSectionForConstant(Kind); 907 908 // The number of sections are small, just do a linear search from the 909 // last section to the first. 910 bool Found = false; 911 unsigned SecIdx = CPSections.size(); 912 while (SecIdx != 0) { 913 if (CPSections[--SecIdx].S == S) { 914 Found = true; 915 break; 916 } 917 } 918 if (!Found) { 919 SecIdx = CPSections.size(); 920 CPSections.push_back(SectionCPs(S, Align)); 921 } 922 923 if (Align > CPSections[SecIdx].Alignment) 924 CPSections[SecIdx].Alignment = Align; 925 CPSections[SecIdx].CPEs.push_back(i); 926 } 927 928 // Now print stuff into the calculated sections. 929 for (unsigned i = 0, e = CPSections.size(); i != e; ++i) { 930 OutStreamer.SwitchSection(CPSections[i].S); 931 EmitAlignment(Log2_32(CPSections[i].Alignment)); 932 933 unsigned Offset = 0; 934 for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) { 935 unsigned CPI = CPSections[i].CPEs[j]; 936 MachineConstantPoolEntry CPE = CP[CPI]; 937 938 // Emit inter-object padding for alignment. 939 unsigned AlignMask = CPE.getAlignment() - 1; 940 unsigned NewOffset = (Offset + AlignMask) & ~AlignMask; 941 OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/); 942 943 const Type *Ty = CPE.getType(); 944 Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty); 945 OutStreamer.EmitLabel(GetCPISymbol(CPI)); 946 947 if (CPE.isMachineConstantPoolEntry()) 948 EmitMachineConstantPoolValue(CPE.Val.MachineCPVal); 949 else 950 EmitGlobalConstant(CPE.Val.ConstVal); 951 } 952 } 953} 954 955/// EmitJumpTableInfo - Print assembly representations of the jump tables used 956/// by the current function to the current output stream. 957/// 958void AsmPrinter::EmitJumpTableInfo() { 959 const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo(); 960 if (MJTI == 0) return; 961 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return; 962 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 963 if (JT.empty()) return; 964 965 // Pick the directive to use to print the jump table entries, and switch to 966 // the appropriate section. 967 const Function *F = MF->getFunction(); 968 bool JTInDiffSection = false; 969 if (// In PIC mode, we need to emit the jump table to the same section as the 970 // function body itself, otherwise the label differences won't make sense. 971 // FIXME: Need a better predicate for this: what about custom entries? 972 MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 || 973 // We should also do if the section name is NULL or function is declared 974 // in discardable section 975 // FIXME: this isn't the right predicate, should be based on the MCSection 976 // for the function. 977 F->isWeakForLinker()) { 978 OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM)); 979 } else { 980 // Otherwise, drop it in the readonly section. 981 const MCSection *ReadOnlySection = 982 getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly()); 983 OutStreamer.SwitchSection(ReadOnlySection); 984 JTInDiffSection = true; 985 } 986 987 EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData()))); 988 989 for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) { 990 const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs; 991 992 // If this jump table was deleted, ignore it. 993 if (JTBBs.empty()) continue; 994 995 // For the EK_LabelDifference32 entry, if the target supports .set, emit a 996 // .set directive for each unique entry. This reduces the number of 997 // relocations the assembler will generate for the jump table. 998 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 && 999 MAI->hasSetDirective()) { 1000 SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets; 1001 const TargetLowering *TLI = TM.getTargetLowering(); 1002 const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext); 1003 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) { 1004 const MachineBasicBlock *MBB = JTBBs[ii]; 1005 if (!EmittedSets.insert(MBB)) continue; 1006 1007 // .set LJTSet, LBB32-base 1008 const MCExpr *LHS = 1009 MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1010 OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()), 1011 MCBinaryExpr::CreateSub(LHS, Base, OutContext)); 1012 } 1013 } 1014 1015 // On some targets (e.g. Darwin) we want to emit two consecutive labels 1016 // before each jump table. The first label is never referenced, but tells 1017 // the assembler and linker the extents of the jump table object. The 1018 // second label is actually referenced by the code. 1019 if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) 1020 // FIXME: This doesn't have to have any specific name, just any randomly 1021 // named and numbered 'l' label would work. Simplify GetJTISymbol. 1022 OutStreamer.EmitLabel(GetJTISymbol(JTI, true)); 1023 1024 OutStreamer.EmitLabel(GetJTISymbol(JTI)); 1025 1026 for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) 1027 EmitJumpTableEntry(MJTI, JTBBs[ii], JTI); 1028 } 1029} 1030 1031/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the 1032/// current stream. 1033void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI, 1034 const MachineBasicBlock *MBB, 1035 unsigned UID) const { 1036 assert(MBB && MBB->getNumber() >= 0 && "Invalid basic block"); 1037 const MCExpr *Value = 0; 1038 switch (MJTI->getEntryKind()) { 1039 case MachineJumpTableInfo::EK_Inline: 1040 llvm_unreachable("Cannot emit EK_Inline jump table entry"); break; 1041 case MachineJumpTableInfo::EK_Custom32: 1042 Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID, 1043 OutContext); 1044 break; 1045 case MachineJumpTableInfo::EK_BlockAddress: 1046 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1047 // .word LBB123 1048 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1049 break; 1050 case MachineJumpTableInfo::EK_GPRel32BlockAddress: { 1051 // EK_GPRel32BlockAddress - Each entry is an address of block, encoded 1052 // with a relocation as gp-relative, e.g.: 1053 // .gprel32 LBB123 1054 MCSymbol *MBBSym = MBB->getSymbol(); 1055 OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext)); 1056 return; 1057 } 1058 1059 case MachineJumpTableInfo::EK_LabelDifference32: { 1060 // EK_LabelDifference32 - Each entry is the address of the block minus 1061 // the address of the jump table. This is used for PIC jump tables where 1062 // gprel32 is not supported. e.g.: 1063 // .word LBB123 - LJTI1_2 1064 // If the .set directive is supported, this is emitted as: 1065 // .set L4_5_set_123, LBB123 - LJTI1_2 1066 // .word L4_5_set_123 1067 1068 // If we have emitted set directives for the jump table entries, print 1069 // them rather than the entries themselves. If we're emitting PIC, then 1070 // emit the table entries as differences between two text section labels. 1071 if (MAI->hasSetDirective()) { 1072 // If we used .set, reference the .set's symbol. 1073 Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()), 1074 OutContext); 1075 break; 1076 } 1077 // Otherwise, use the difference as the jump table entry. 1078 Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext); 1079 const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext); 1080 Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext); 1081 break; 1082 } 1083 } 1084 1085 assert(Value && "Unknown entry kind!"); 1086 1087 unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData()); 1088 OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0); 1089} 1090 1091 1092/// EmitSpecialLLVMGlobal - Check to see if the specified global is a 1093/// special global used by LLVM. If so, emit it and return true, otherwise 1094/// do nothing and return false. 1095bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) { 1096 if (GV->getName() == "llvm.used") { 1097 if (MAI->hasNoDeadStrip()) // No need to emit this at all. 1098 EmitLLVMUsedList(GV->getInitializer()); 1099 return true; 1100 } 1101 1102 // Ignore debug and non-emitted data. This handles llvm.compiler.used. 1103 if (GV->getSection() == "llvm.metadata" || 1104 GV->hasAvailableExternallyLinkage()) 1105 return true; 1106 1107 if (!GV->hasAppendingLinkage()) return false; 1108 1109 assert(GV->hasInitializer() && "Not a special LLVM global!"); 1110 1111 const TargetData *TD = TM.getTargetData(); 1112 unsigned Align = Log2_32(TD->getPointerPrefAlignment()); 1113 if (GV->getName() == "llvm.global_ctors") { 1114 OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection()); 1115 EmitAlignment(Align); 1116 EmitXXStructorList(GV->getInitializer()); 1117 1118 if (TM.getRelocationModel() == Reloc::Static && 1119 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1120 StringRef Sym(".constructors_used"); 1121 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1122 MCSA_Reference); 1123 } 1124 return true; 1125 } 1126 1127 if (GV->getName() == "llvm.global_dtors") { 1128 OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection()); 1129 EmitAlignment(Align); 1130 EmitXXStructorList(GV->getInitializer()); 1131 1132 if (TM.getRelocationModel() == Reloc::Static && 1133 MAI->hasStaticCtorDtorReferenceInStaticMode()) { 1134 StringRef Sym(".destructors_used"); 1135 OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym), 1136 MCSA_Reference); 1137 } 1138 return true; 1139 } 1140 1141 return false; 1142} 1143 1144/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each 1145/// global in the specified llvm.used list for which emitUsedDirectiveFor 1146/// is true, as being used with this directive. 1147void AsmPrinter::EmitLLVMUsedList(Constant *List) { 1148 // Should be an array of 'i8*'. 1149 ConstantArray *InitList = dyn_cast<ConstantArray>(List); 1150 if (InitList == 0) return; 1151 1152 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) { 1153 const GlobalValue *GV = 1154 dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts()); 1155 if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) 1156 OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip); 1157 } 1158} 1159 1160/// EmitXXStructorList - Emit the ctor or dtor list. This just prints out the 1161/// function pointers, ignoring the init priority. 1162void AsmPrinter::EmitXXStructorList(Constant *List) { 1163 // Should be an array of '{ int, void ()* }' structs. The first value is the 1164 // init priority, which we ignore. 1165 if (!isa<ConstantArray>(List)) return; 1166 ConstantArray *InitList = cast<ConstantArray>(List); 1167 for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) 1168 if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){ 1169 if (CS->getNumOperands() != 2) return; // Not array of 2-element structs. 1170 1171 if (CS->getOperand(1)->isNullValue()) 1172 return; // Found a null terminator, exit printing. 1173 // Emit the function pointer. 1174 EmitGlobalConstant(CS->getOperand(1)); 1175 } 1176} 1177 1178//===--------------------------------------------------------------------===// 1179// Emission and print routines 1180// 1181 1182/// EmitInt8 - Emit a byte directive and value. 1183/// 1184void AsmPrinter::EmitInt8(int Value) const { 1185 OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/); 1186} 1187 1188/// EmitInt16 - Emit a short directive and value. 1189/// 1190void AsmPrinter::EmitInt16(int Value) const { 1191 OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/); 1192} 1193 1194/// EmitInt32 - Emit a long directive and value. 1195/// 1196void AsmPrinter::EmitInt32(int Value) const { 1197 OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/); 1198} 1199 1200/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size 1201/// in bytes of the directive is specified by Size and Hi/Lo specify the 1202/// labels. This implicitly uses .set if it is available. 1203void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo, 1204 unsigned Size) const { 1205 // Get the Hi-Lo expression. 1206 const MCExpr *Diff = 1207 MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext), 1208 MCSymbolRefExpr::Create(Lo, OutContext), 1209 OutContext); 1210 1211 if (!MAI->hasSetDirective()) { 1212 OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/); 1213 return; 1214 } 1215 1216 // Otherwise, emit with .set (aka assignment). 1217 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1218 OutStreamer.EmitAssignment(SetLabel, Diff); 1219 OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/); 1220} 1221 1222/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo" 1223/// where the size in bytes of the directive is specified by Size and Hi/Lo 1224/// specify the labels. This implicitly uses .set if it is available. 1225void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset, 1226 const MCSymbol *Lo, unsigned Size) 1227 const { 1228 1229 // Emit Hi+Offset - Lo 1230 // Get the Hi+Offset expression. 1231 const MCExpr *Plus = 1232 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext), 1233 MCConstantExpr::Create(Offset, OutContext), 1234 OutContext); 1235 1236 // Get the Hi+Offset-Lo expression. 1237 const MCExpr *Diff = 1238 MCBinaryExpr::CreateSub(Plus, 1239 MCSymbolRefExpr::Create(Lo, OutContext), 1240 OutContext); 1241 1242 if (!MAI->hasSetDirective()) 1243 OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/); 1244 else { 1245 // Otherwise, emit with .set (aka assignment). 1246 MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++); 1247 OutStreamer.EmitAssignment(SetLabel, Diff); 1248 OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/); 1249 } 1250} 1251 1252/// EmitLabelPlusOffset - Emit something like ".long Label+Offset" 1253/// where the size in bytes of the directive is specified by Size and Label 1254/// specifies the label. This implicitly uses .set if it is available. 1255void AsmPrinter::EmitLabelPlusOffset(const MCSymbol *Label, uint64_t Offset, 1256 unsigned Size) 1257 const { 1258 1259 // Emit Label+Offset 1260 const MCExpr *Plus = 1261 MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Label, OutContext), 1262 MCConstantExpr::Create(Offset, OutContext), 1263 OutContext); 1264 1265 OutStreamer.EmitValue(Plus, 4, 0/*AddrSpace*/); 1266} 1267 1268 1269//===----------------------------------------------------------------------===// 1270 1271// EmitAlignment - Emit an alignment directive to the specified power of 1272// two boundary. For example, if you pass in 3 here, you will get an 8 1273// byte alignment. If a global value is specified, and if that global has 1274// an explicit alignment requested, it will override the alignment request 1275// if required for correctness. 1276// 1277void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const { 1278 if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits); 1279 1280 if (NumBits == 0) return; // 1-byte aligned: no need to emit alignment. 1281 1282 if (getCurrentSection()->getKind().isText()) 1283 OutStreamer.EmitCodeAlignment(1 << NumBits); 1284 else 1285 OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0); 1286} 1287 1288//===----------------------------------------------------------------------===// 1289// Constant emission. 1290//===----------------------------------------------------------------------===// 1291 1292/// LowerConstant - Lower the specified LLVM Constant to an MCExpr. 1293/// 1294static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) { 1295 MCContext &Ctx = AP.OutContext; 1296 1297 if (CV->isNullValue() || isa<UndefValue>(CV)) 1298 return MCConstantExpr::Create(0, Ctx); 1299 1300 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) 1301 return MCConstantExpr::Create(CI->getZExtValue(), Ctx); 1302 1303 if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) 1304 return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx); 1305 1306 if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) 1307 return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx); 1308 1309 const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV); 1310 if (CE == 0) { 1311 llvm_unreachable("Unknown constant value to lower!"); 1312 return MCConstantExpr::Create(0, Ctx); 1313 } 1314 1315 switch (CE->getOpcode()) { 1316 default: 1317 // If the code isn't optimized, there may be outstanding folding 1318 // opportunities. Attempt to fold the expression using TargetData as a 1319 // last resort before giving up. 1320 if (Constant *C = 1321 ConstantFoldConstantExpression(CE, AP.TM.getTargetData())) 1322 if (C != CE) 1323 return LowerConstant(C, AP); 1324 1325 // Otherwise report the problem to the user. 1326 { 1327 std::string S; 1328 raw_string_ostream OS(S); 1329 OS << "Unsupported expression in static initializer: "; 1330 WriteAsOperand(OS, CE, /*PrintType=*/false, 1331 !AP.MF ? 0 : AP.MF->getFunction()->getParent()); 1332 report_fatal_error(OS.str()); 1333 } 1334 return MCConstantExpr::Create(0, Ctx); 1335 case Instruction::GetElementPtr: { 1336 const TargetData &TD = *AP.TM.getTargetData(); 1337 // Generate a symbolic expression for the byte address 1338 const Constant *PtrVal = CE->getOperand(0); 1339 SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end()); 1340 int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0], 1341 IdxVec.size()); 1342 1343 const MCExpr *Base = LowerConstant(CE->getOperand(0), AP); 1344 if (Offset == 0) 1345 return Base; 1346 1347 // Truncate/sext the offset to the pointer size. 1348 if (TD.getPointerSizeInBits() != 64) { 1349 int SExtAmount = 64-TD.getPointerSizeInBits(); 1350 Offset = (Offset << SExtAmount) >> SExtAmount; 1351 } 1352 1353 return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx), 1354 Ctx); 1355 } 1356 1357 case Instruction::Trunc: 1358 // We emit the value and depend on the assembler to truncate the generated 1359 // expression properly. This is important for differences between 1360 // blockaddress labels. Since the two labels are in the same function, it 1361 // is reasonable to treat their delta as a 32-bit value. 1362 // FALL THROUGH. 1363 case Instruction::BitCast: 1364 return LowerConstant(CE->getOperand(0), AP); 1365 1366 case Instruction::IntToPtr: { 1367 const TargetData &TD = *AP.TM.getTargetData(); 1368 // Handle casts to pointers by changing them into casts to the appropriate 1369 // integer type. This promotes constant folding and simplifies this code. 1370 Constant *Op = CE->getOperand(0); 1371 Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()), 1372 false/*ZExt*/); 1373 return LowerConstant(Op, AP); 1374 } 1375 1376 case Instruction::PtrToInt: { 1377 const TargetData &TD = *AP.TM.getTargetData(); 1378 // Support only foldable casts to/from pointers that can be eliminated by 1379 // changing the pointer to the appropriately sized integer type. 1380 Constant *Op = CE->getOperand(0); 1381 const Type *Ty = CE->getType(); 1382 1383 const MCExpr *OpExpr = LowerConstant(Op, AP); 1384 1385 // We can emit the pointer value into this slot if the slot is an 1386 // integer slot equal to the size of the pointer. 1387 if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType())) 1388 return OpExpr; 1389 1390 // Otherwise the pointer is smaller than the resultant integer, mask off 1391 // the high bits so we are sure to get a proper truncation if the input is 1392 // a constant expr. 1393 unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType()); 1394 const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx); 1395 return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx); 1396 } 1397 1398 // The MC library also has a right-shift operator, but it isn't consistently 1399 // signed or unsigned between different targets. 1400 case Instruction::Add: 1401 case Instruction::Sub: 1402 case Instruction::Mul: 1403 case Instruction::SDiv: 1404 case Instruction::SRem: 1405 case Instruction::Shl: 1406 case Instruction::And: 1407 case Instruction::Or: 1408 case Instruction::Xor: { 1409 const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP); 1410 const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP); 1411 switch (CE->getOpcode()) { 1412 default: llvm_unreachable("Unknown binary operator constant cast expr"); 1413 case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx); 1414 case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); 1415 case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx); 1416 case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx); 1417 case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx); 1418 case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx); 1419 case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx); 1420 case Instruction::Or: return MCBinaryExpr::CreateOr (LHS, RHS, Ctx); 1421 case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx); 1422 } 1423 } 1424 } 1425} 1426 1427static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace, 1428 AsmPrinter &AP); 1429 1430static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace, 1431 AsmPrinter &AP) { 1432 if (AddrSpace != 0 || !CA->isString()) { 1433 // Not a string. Print the values in successive locations 1434 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1435 EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP); 1436 return; 1437 } 1438 1439 // Otherwise, it can be emitted as .ascii. 1440 SmallVector<char, 128> TmpVec; 1441 TmpVec.reserve(CA->getNumOperands()); 1442 for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i) 1443 TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue()); 1444 1445 AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace); 1446} 1447 1448static void EmitGlobalConstantVector(const ConstantVector *CV, 1449 unsigned AddrSpace, AsmPrinter &AP) { 1450 for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i) 1451 EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP); 1452} 1453 1454static void EmitGlobalConstantStruct(const ConstantStruct *CS, 1455 unsigned AddrSpace, AsmPrinter &AP) { 1456 // Print the fields in successive locations. Pad to align if needed! 1457 const TargetData *TD = AP.TM.getTargetData(); 1458 unsigned Size = TD->getTypeAllocSize(CS->getType()); 1459 const StructLayout *Layout = TD->getStructLayout(CS->getType()); 1460 uint64_t SizeSoFar = 0; 1461 for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) { 1462 const Constant *Field = CS->getOperand(i); 1463 1464 // Check if padding is needed and insert one or more 0s. 1465 uint64_t FieldSize = TD->getTypeAllocSize(Field->getType()); 1466 uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1)) 1467 - Layout->getElementOffset(i)) - FieldSize; 1468 SizeSoFar += FieldSize + PadSize; 1469 1470 // Now print the actual field value. 1471 EmitGlobalConstantImpl(Field, AddrSpace, AP); 1472 1473 // Insert padding - this may include padding to increase the size of the 1474 // current field up to the ABI size (if the struct is not packed) as well 1475 // as padding to ensure that the next field starts at the right offset. 1476 AP.OutStreamer.EmitZeros(PadSize, AddrSpace); 1477 } 1478 assert(SizeSoFar == Layout->getSizeInBytes() && 1479 "Layout of constant struct may be incorrect!"); 1480} 1481 1482static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace, 1483 AsmPrinter &AP) { 1484 // FP Constants are printed as integer constants to avoid losing 1485 // precision. 1486 if (CFP->getType()->isDoubleTy()) { 1487 if (AP.isVerbose()) { 1488 double Val = CFP->getValueAPF().convertToDouble(); 1489 AP.OutStreamer.GetCommentOS() << "double " << Val << '\n'; 1490 } 1491 1492 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1493 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1494 return; 1495 } 1496 1497 if (CFP->getType()->isFloatTy()) { 1498 if (AP.isVerbose()) { 1499 float Val = CFP->getValueAPF().convertToFloat(); 1500 AP.OutStreamer.GetCommentOS() << "float " << Val << '\n'; 1501 } 1502 uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue(); 1503 AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace); 1504 return; 1505 } 1506 1507 if (CFP->getType()->isX86_FP80Ty()) { 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.isVerbose()) { 1513 // Convert to double so we can print the approximate val as a comment. 1514 APFloat DoubleVal = CFP->getValueAPF(); 1515 bool ignored; 1516 DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven, 1517 &ignored); 1518 AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= " 1519 << DoubleVal.convertToDouble() << '\n'; 1520 } 1521 1522 if (AP.TM.getTargetData()->isBigEndian()) { 1523 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1524 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1525 } else { 1526 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1527 AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace); 1528 } 1529 1530 // Emit the tail padding for the long double. 1531 const TargetData &TD = *AP.TM.getTargetData(); 1532 AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) - 1533 TD.getTypeStoreSize(CFP->getType()), AddrSpace); 1534 return; 1535 } 1536 1537 assert(CFP->getType()->isPPC_FP128Ty() && 1538 "Floating point constant type not handled"); 1539 // All long double variants are printed as hex 1540 // API needed to prevent premature destruction. 1541 APInt API = CFP->getValueAPF().bitcastToAPInt(); 1542 const uint64_t *p = API.getRawData(); 1543 if (AP.TM.getTargetData()->isBigEndian()) { 1544 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1545 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1546 } else { 1547 AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace); 1548 AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace); 1549 } 1550} 1551 1552static void EmitGlobalConstantLargeInt(const ConstantInt *CI, 1553 unsigned AddrSpace, AsmPrinter &AP) { 1554 const TargetData *TD = AP.TM.getTargetData(); 1555 unsigned BitWidth = CI->getBitWidth(); 1556 assert((BitWidth & 63) == 0 && "only support multiples of 64-bits"); 1557 1558 // We don't expect assemblers to support integer data directives 1559 // for more than 64 bits, so we emit the data in at most 64-bit 1560 // quantities at a time. 1561 const uint64_t *RawData = CI->getValue().getRawData(); 1562 for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) { 1563 uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i]; 1564 AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace); 1565 } 1566} 1567 1568static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace, 1569 AsmPrinter &AP) { 1570 if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) { 1571 uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1572 return AP.OutStreamer.EmitZeros(Size, AddrSpace); 1573 } 1574 1575 if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) { 1576 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1577 switch (Size) { 1578 case 1: 1579 case 2: 1580 case 4: 1581 case 8: 1582 if (AP.isVerbose()) 1583 AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue()); 1584 AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace); 1585 return; 1586 default: 1587 EmitGlobalConstantLargeInt(CI, AddrSpace, AP); 1588 return; 1589 } 1590 } 1591 1592 if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV)) 1593 return EmitGlobalConstantArray(CVA, AddrSpace, AP); 1594 1595 if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV)) 1596 return EmitGlobalConstantStruct(CVS, AddrSpace, AP); 1597 1598 if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV)) 1599 return EmitGlobalConstantFP(CFP, AddrSpace, AP); 1600 1601 if (isa<ConstantPointerNull>(CV)) { 1602 unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType()); 1603 AP.OutStreamer.EmitIntValue(0, Size, AddrSpace); 1604 return; 1605 } 1606 1607 if (const ConstantVector *V = dyn_cast<ConstantVector>(CV)) 1608 return EmitGlobalConstantVector(V, AddrSpace, AP); 1609 1610 // Otherwise, it must be a ConstantExpr. Lower it to an MCExpr, then emit it 1611 // thread the streamer with EmitValue. 1612 AP.OutStreamer.EmitValue(LowerConstant(CV, AP), 1613 AP.TM.getTargetData()->getTypeAllocSize(CV->getType()), 1614 AddrSpace); 1615} 1616 1617/// EmitGlobalConstant - Print a general LLVM constant to the .s file. 1618void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) { 1619 uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType()); 1620 if (Size) 1621 EmitGlobalConstantImpl(CV, AddrSpace, *this); 1622 else if (MAI->hasSubsectionsViaSymbols()) { 1623 // If the global has zero size, emit a single byte so that two labels don't 1624 // look like they are at the same location. 1625 OutStreamer.EmitIntValue(0, 1, AddrSpace); 1626 } 1627} 1628 1629void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) { 1630 // Target doesn't support this yet! 1631 llvm_unreachable("Target does not support EmitMachineConstantPoolValue"); 1632} 1633 1634void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const { 1635 if (Offset > 0) 1636 OS << '+' << Offset; 1637 else if (Offset < 0) 1638 OS << Offset; 1639} 1640 1641//===----------------------------------------------------------------------===// 1642// Symbol Lowering Routines. 1643//===----------------------------------------------------------------------===// 1644 1645/// GetTempSymbol - Return the MCSymbol corresponding to the assembler 1646/// temporary label with the specified stem and unique ID. 1647MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const { 1648 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) + 1649 Name + Twine(ID)); 1650} 1651 1652/// GetTempSymbol - Return an assembler temporary label with the specified 1653/// stem. 1654MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const { 1655 return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+ 1656 Name); 1657} 1658 1659 1660MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const { 1661 return MMI->getAddrLabelSymbol(BA->getBasicBlock()); 1662} 1663 1664MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const { 1665 return MMI->getAddrLabelSymbol(BB); 1666} 1667 1668/// GetCPISymbol - Return the symbol for the specified constant pool entry. 1669MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const { 1670 return OutContext.GetOrCreateSymbol 1671 (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber()) 1672 + "_" + Twine(CPID)); 1673} 1674 1675/// GetJTISymbol - Return the symbol for the specified jump table entry. 1676MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const { 1677 return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate); 1678} 1679 1680/// GetJTSetSymbol - Return the symbol for the specified jump table .set 1681/// FIXME: privatize to AsmPrinter. 1682MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const { 1683 return OutContext.GetOrCreateSymbol 1684 (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" + 1685 Twine(UID) + "_set_" + Twine(MBBID)); 1686} 1687 1688/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with 1689/// global value name as its base, with the specified suffix, and where the 1690/// symbol is forced to have private linkage if ForcePrivate is true. 1691MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV, 1692 StringRef Suffix, 1693 bool ForcePrivate) const { 1694 SmallString<60> NameStr; 1695 Mang->getNameWithPrefix(NameStr, GV, ForcePrivate); 1696 NameStr.append(Suffix.begin(), Suffix.end()); 1697 return OutContext.GetOrCreateSymbol(NameStr.str()); 1698} 1699 1700/// GetExternalSymbolSymbol - Return the MCSymbol for the specified 1701/// ExternalSymbol. 1702MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const { 1703 SmallString<60> NameStr; 1704 Mang->getNameWithPrefix(NameStr, Sym); 1705 return OutContext.GetOrCreateSymbol(NameStr.str()); 1706} 1707 1708 1709 1710/// PrintParentLoopComment - Print comments about parent loops of this one. 1711static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1712 unsigned FunctionNumber) { 1713 if (Loop == 0) return; 1714 PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber); 1715 OS.indent(Loop->getLoopDepth()*2) 1716 << "Parent Loop BB" << FunctionNumber << "_" 1717 << Loop->getHeader()->getNumber() 1718 << " Depth=" << Loop->getLoopDepth() << '\n'; 1719} 1720 1721 1722/// PrintChildLoopComment - Print comments about child loops within 1723/// the loop for this basic block, with nesting. 1724static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop, 1725 unsigned FunctionNumber) { 1726 // Add child loop information 1727 for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){ 1728 OS.indent((*CL)->getLoopDepth()*2) 1729 << "Child Loop BB" << FunctionNumber << "_" 1730 << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth() 1731 << '\n'; 1732 PrintChildLoopComment(OS, *CL, FunctionNumber); 1733 } 1734} 1735 1736/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks. 1737static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB, 1738 const MachineLoopInfo *LI, 1739 const AsmPrinter &AP) { 1740 // Add loop depth information 1741 const MachineLoop *Loop = LI->getLoopFor(&MBB); 1742 if (Loop == 0) return; 1743 1744 MachineBasicBlock *Header = Loop->getHeader(); 1745 assert(Header && "No header for loop"); 1746 1747 // If this block is not a loop header, just print out what is the loop header 1748 // and return. 1749 if (Header != &MBB) { 1750 AP.OutStreamer.AddComment(" in Loop: Header=BB" + 1751 Twine(AP.getFunctionNumber())+"_" + 1752 Twine(Loop->getHeader()->getNumber())+ 1753 " Depth="+Twine(Loop->getLoopDepth())); 1754 return; 1755 } 1756 1757 // Otherwise, it is a loop header. Print out information about child and 1758 // parent loops. 1759 raw_ostream &OS = AP.OutStreamer.GetCommentOS(); 1760 1761 PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber()); 1762 1763 OS << "=>"; 1764 OS.indent(Loop->getLoopDepth()*2-2); 1765 1766 OS << "This "; 1767 if (Loop->empty()) 1768 OS << "Inner "; 1769 OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n'; 1770 1771 PrintChildLoopComment(OS, Loop, AP.getFunctionNumber()); 1772} 1773 1774 1775/// EmitBasicBlockStart - This method prints the label for the specified 1776/// MachineBasicBlock, an alignment (if present) and a comment describing 1777/// it if appropriate. 1778void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const { 1779 // Emit an alignment directive for this block, if needed. 1780 if (unsigned Align = MBB->getAlignment()) 1781 EmitAlignment(Log2_32(Align)); 1782 1783 // If the block has its address taken, emit any labels that were used to 1784 // reference the block. It is possible that there is more than one label 1785 // here, because multiple LLVM BB's may have been RAUW'd to this block after 1786 // the references were generated. 1787 if (MBB->hasAddressTaken()) { 1788 const BasicBlock *BB = MBB->getBasicBlock(); 1789 if (isVerbose()) 1790 OutStreamer.AddComment("Block address taken"); 1791 1792 std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB); 1793 1794 for (unsigned i = 0, e = Syms.size(); i != e; ++i) 1795 OutStreamer.EmitLabel(Syms[i]); 1796 } 1797 1798 // Print the main label for the block. 1799 if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) { 1800 if (isVerbose() && OutStreamer.hasRawTextSupport()) { 1801 if (const BasicBlock *BB = MBB->getBasicBlock()) 1802 if (BB->hasName()) 1803 OutStreamer.AddComment("%" + BB->getName()); 1804 1805 EmitBasicBlockLoopComments(*MBB, LI, *this); 1806 1807 // NOTE: Want this comment at start of line, don't emit with AddComment. 1808 OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" + 1809 Twine(MBB->getNumber()) + ":"); 1810 } 1811 } else { 1812 if (isVerbose()) { 1813 if (const BasicBlock *BB = MBB->getBasicBlock()) 1814 if (BB->hasName()) 1815 OutStreamer.AddComment("%" + BB->getName()); 1816 EmitBasicBlockLoopComments(*MBB, LI, *this); 1817 } 1818 1819 OutStreamer.EmitLabel(MBB->getSymbol()); 1820 } 1821} 1822 1823void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const { 1824 MCSymbolAttr Attr = MCSA_Invalid; 1825 1826 switch (Visibility) { 1827 default: break; 1828 case GlobalValue::HiddenVisibility: 1829 Attr = MAI->getHiddenVisibilityAttr(); 1830 break; 1831 case GlobalValue::ProtectedVisibility: 1832 Attr = MAI->getProtectedVisibilityAttr(); 1833 break; 1834 } 1835 1836 if (Attr != MCSA_Invalid) 1837 OutStreamer.EmitSymbolAttribute(Sym, Attr); 1838} 1839 1840/// isBlockOnlyReachableByFallthough - Return true if the basic block has 1841/// exactly one predecessor and the control transfer mechanism between 1842/// the predecessor and this block is a fall-through. 1843bool AsmPrinter:: 1844isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const { 1845 // If this is a landing pad, it isn't a fall through. If it has no preds, 1846 // then nothing falls through to it. 1847 if (MBB->isLandingPad() || MBB->pred_empty()) 1848 return false; 1849 1850 // If there isn't exactly one predecessor, it can't be a fall through. 1851 MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI; 1852 ++PI2; 1853 if (PI2 != MBB->pred_end()) 1854 return false; 1855 1856 // The predecessor has to be immediately before this block. 1857 const MachineBasicBlock *Pred = *PI; 1858 1859 if (!Pred->isLayoutSuccessor(MBB)) 1860 return false; 1861 1862 // If the block is completely empty, then it definitely does fall through. 1863 if (Pred->empty()) 1864 return true; 1865 1866 // Otherwise, check the last instruction. 1867 const MachineInstr &LastInst = Pred->back(); 1868 return !LastInst.getDesc().isBarrier(); 1869} 1870 1871 1872 1873GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) { 1874 if (!S->usesMetadata()) 1875 return 0; 1876 1877 gcp_map_type &GCMap = getGCMap(GCMetadataPrinters); 1878 gcp_map_type::iterator GCPI = GCMap.find(S); 1879 if (GCPI != GCMap.end()) 1880 return GCPI->second; 1881 1882 const char *Name = S->getName().c_str(); 1883 1884 for (GCMetadataPrinterRegistry::iterator 1885 I = GCMetadataPrinterRegistry::begin(), 1886 E = GCMetadataPrinterRegistry::end(); I != E; ++I) 1887 if (strcmp(Name, I->getName()) == 0) { 1888 GCMetadataPrinter *GMP = I->instantiate(); 1889 GMP->S = S; 1890 GCMap.insert(std::make_pair(S, GMP)); 1891 return GMP; 1892 } 1893 1894 report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name)); 1895 return 0; 1896} 1897 1898