AsmPrinter.cpp revision 91bead790518fcf5cb26019fb1ebf2372e8a5b3f 
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 "llvm/Assembly/Writer.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constants.h"
19#include "llvm/Module.h"
20#include "llvm/CodeGen/DwarfWriter.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/MCContext.h"
31#include "llvm/MC/MCExpr.h"
32#include "llvm/MC/MCInst.h"
33#include "llvm/MC/MCSection.h"
34#include "llvm/MC/MCStreamer.h"
35#include "llvm/MC/MCSymbol.h"
36#include "llvm/MC/MCAsmInfo.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/TargetOptions.h"
43#include "llvm/Target/TargetRegisterInfo.h"
44#include "llvm/ADT/SmallPtrSet.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/ADT/Statistic.h"
47#include "llvm/Support/CommandLine.h"
48#include "llvm/Support/Debug.h"
49#include "llvm/Support/ErrorHandling.h"
50#include "llvm/Support/Format.h"
51#include "llvm/Support/FormattedStream.h"
52#include <cerrno>
53using namespace llvm;
54
55STATISTIC(EmittedInsts, "Number of machine instrs printed");
56
57char AsmPrinter::ID = 0;
58
59AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
60                       MCStreamer &Streamer)
61  : MachineFunctionPass(&ID), O(o),
62    TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()),
63    OutContext(Streamer.getContext()),
64    OutStreamer(Streamer),
65    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
66  DW = 0; MMI = 0;
67  VerboseAsm = Streamer.isVerboseAsm();
68}
69
70AsmPrinter::~AsmPrinter() {
71  for (gcp_iterator I = GCMetadataPrinters.begin(),
72                    E = GCMetadataPrinters.end(); I != E; ++I)
73    delete I->second;
74
75  delete &OutStreamer;
76}
77
78/// getFunctionNumber - Return a unique ID for the current function.
79///
80unsigned AsmPrinter::getFunctionNumber() const {
81  return MF->getFunctionNumber();
82}
83
84TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
85  return TM.getTargetLowering()->getObjFileLowering();
86}
87
88/// getCurrentSection() - Return the current section we are emitting to.
89const MCSection *AsmPrinter::getCurrentSection() const {
90  return OutStreamer.getCurrentSection();
91}
92
93
94void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
95  AU.setPreservesAll();
96  MachineFunctionPass::getAnalysisUsage(AU);
97  AU.addRequired<MachineModuleInfo>();
98  AU.addRequired<GCModuleInfo>();
99  if (VerboseAsm)
100    AU.addRequired<MachineLoopInfo>();
101}
102
103bool AsmPrinter::doInitialization(Module &M) {
104  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
105  MMI->AnalyzeModule(M);
106
107  // Initialize TargetLoweringObjectFile.
108  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
109    .Initialize(OutContext, TM);
110
111  Mang = new Mangler(OutContext, *TM.getTargetData());
112
113  // Allow the target to emit any magic that it wants at the start of the file.
114  EmitStartOfAsmFile(M);
115
116  // Very minimal debug info. It is ignored if we emit actual debug info. If we
117  // don't, this at least helps the user find where a global came from.
118  if (MAI->hasSingleParameterDotFile()) {
119    // .file "foo.c"
120    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
121  }
122
123  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
124  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
125  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
126    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
127      MP->beginAssembly(O, *this, *MAI);
128
129  // Emit module-level inline asm if it exists.
130  if (!M.getModuleInlineAsm().empty()) {
131    OutStreamer.AddComment("Start of file scope inline assembly");
132    OutStreamer.AddBlankLine();
133    EmitInlineAsm(M.getModuleInlineAsm());
134    OutStreamer.AddComment("End of file scope inline assembly");
135    OutStreamer.AddBlankLine();
136  }
137
138  DW = getAnalysisIfAvailable<DwarfWriter>();
139  if (DW)
140    DW->BeginModule(&M, MMI, O, this, MAI);
141
142  return false;
143}
144
145void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
146  switch ((GlobalValue::LinkageTypes)Linkage) {
147  case GlobalValue::CommonLinkage:
148  case GlobalValue::LinkOnceAnyLinkage:
149  case GlobalValue::LinkOnceODRLinkage:
150  case GlobalValue::WeakAnyLinkage:
151  case GlobalValue::WeakODRLinkage:
152  case GlobalValue::LinkerPrivateLinkage:
153    if (MAI->getWeakDefDirective() != 0) {
154      // .globl _foo
155      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
156      // .weak_definition _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
158    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
159      // .globl _foo
160      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
161      // FIXME: linkonce should be a section attribute, handled by COFF Section
162      // assignment.
163      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
164      // .linkonce discard
165      // FIXME: It would be nice to use .linkonce samesize for non-common
166      // globals.
167      O << LinkOnce;
168    } else {
169      // .weak _foo
170      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
171    }
172    break;
173  case GlobalValue::DLLExportLinkage:
174  case GlobalValue::AppendingLinkage:
175    // FIXME: appending linkage variables should go into a section of
176    // their name or something.  For now, just emit them as external.
177  case GlobalValue::ExternalLinkage:
178    // If external or appending, declare as a global symbol.
179    // .globl _foo
180    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
181    break;
182  case GlobalValue::PrivateLinkage:
183  case GlobalValue::InternalLinkage:
184    break;
185  default:
186    llvm_unreachable("Unknown linkage type!");
187  }
188}
189
190
191/// EmitGlobalVariable - Emit the specified global variable to the .s file.
192void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
193  if (!GV->hasInitializer())   // External globals require no code.
194    return;
195
196  // Check to see if this is a special global used by LLVM, if so, emit it.
197  if (EmitSpecialLLVMGlobal(GV))
198    return;
199
200  MCSymbol *GVSym = Mang->getSymbol(GV);
201  EmitVisibility(GVSym, GV->getVisibility());
202
203  if (MAI->hasDotTypeDotSizeDirective())
204    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
205
206  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
207
208  const TargetData *TD = TM.getTargetData();
209  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
210  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
211
212  // Handle common and BSS local symbols (.lcomm).
213  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
214    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
215
216    if (VerboseAsm) {
217      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
218                     /*PrintType=*/false, GV->getParent());
219      OutStreamer.GetCommentOS() << '\n';
220    }
221
222    // Handle common symbols.
223    if (GVKind.isCommon()) {
224      // .comm _foo, 42, 4
225      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
226      return;
227    }
228
229    // Handle local BSS symbols.
230    if (MAI->hasMachoZeroFillDirective()) {
231      const MCSection *TheSection =
232        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
233      // .zerofill __DATA, __bss, _foo, 400, 5
234      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
235      return;
236    }
237
238    if (MAI->hasLCOMMDirective()) {
239      // .lcomm _foo, 42
240      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
241      return;
242    }
243
244    // .local _foo
245    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
246    // .comm _foo, 42, 4
247    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
248    return;
249  }
250
251  const MCSection *TheSection =
252    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
253
254  // Handle the zerofill directive on darwin, which is a special form of BSS
255  // emission.
256  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
257    // .globl _foo
258    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
259    // .zerofill __DATA, __common, _foo, 400, 5
260    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
261    return;
262  }
263
264  OutStreamer.SwitchSection(TheSection);
265
266  EmitLinkage(GV->getLinkage(), GVSym);
267  EmitAlignment(AlignLog, GV);
268
269  if (VerboseAsm) {
270    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
271                   /*PrintType=*/false, GV->getParent());
272    OutStreamer.GetCommentOS() << '\n';
273  }
274  OutStreamer.EmitLabel(GVSym);
275
276  EmitGlobalConstant(GV->getInitializer());
277
278  if (MAI->hasDotTypeDotSizeDirective())
279    // .size foo, 42
280    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
281
282  OutStreamer.AddBlankLine();
283}
284
285/// EmitFunctionHeader - This method emits the header for the current
286/// function.
287void AsmPrinter::EmitFunctionHeader() {
288  // Print out constants referenced by the function
289  EmitConstantPool();
290
291  // Print the 'header' of function.
292  const Function *F = MF->getFunction();
293
294  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
295  EmitVisibility(CurrentFnSym, F->getVisibility());
296
297  EmitLinkage(F->getLinkage(), CurrentFnSym);
298  EmitAlignment(MF->getAlignment(), F);
299
300  if (MAI->hasDotTypeDotSizeDirective())
301    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
302
303  if (VerboseAsm) {
304    WriteAsOperand(OutStreamer.GetCommentOS(), F,
305                   /*PrintType=*/false, F->getParent());
306    OutStreamer.GetCommentOS() << '\n';
307  }
308
309  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
310  // do their wild and crazy things as required.
311  EmitFunctionEntryLabel();
312
313  // If the function had address-taken blocks that got deleted, then we have
314  // references to the dangling symbols.  Emit them at the start of the function
315  // so that we don't get references to undefined symbols.
316  std::vector<MCSymbol*> DeadBlockSyms;
317  MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
318  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
319    OutStreamer.AddComment("Address taken block that was later removed");
320    OutStreamer.EmitLabel(DeadBlockSyms[i]);
321  }
322
323  // Add some workaround for linkonce linkage on Cygwin\MinGW.
324  if (MAI->getLinkOnceDirective() != 0 &&
325      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
326    // FIXME: What is this?
327    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
328
329  // Emit pre-function debug and/or EH information.
330  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
331    DW->BeginFunction(MF);
332}
333
334/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
335/// function.  This can be overridden by targets as required to do custom stuff.
336void AsmPrinter::EmitFunctionEntryLabel() {
337  OutStreamer.EmitLabel(CurrentFnSym);
338}
339
340
341/// EmitComments - Pretty-print comments for instructions.
342static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
343  const MachineFunction *MF = MI.getParent()->getParent();
344  const TargetMachine &TM = MF->getTarget();
345
346  DebugLoc DL = MI.getDebugLoc();
347  if (!DL.isUnknown()) {          // Print source line info.
348    DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
349    // Omit the directory, because it's likely to be long and uninteresting.
350    if (Scope.Verify())
351      CommentOS << Scope.getFilename();
352    else
353      CommentOS << "<unknown>";
354    CommentOS << ':' << DL.getLine();
355    if (DL.getCol() != 0)
356      CommentOS << ':' << DL.getCol();
357    CommentOS << '\n';
358  }
359
360  // Check for spills and reloads
361  int FI;
362
363  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
364
365  // We assume a single instruction only has a spill or reload, not
366  // both.
367  const MachineMemOperand *MMO;
368  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
369    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
370      MMO = *MI.memoperands_begin();
371      CommentOS << MMO->getSize() << "-byte Reload\n";
372    }
373  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
374    if (FrameInfo->isSpillSlotObjectIndex(FI))
375      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
376  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
377    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
378      MMO = *MI.memoperands_begin();
379      CommentOS << MMO->getSize() << "-byte Spill\n";
380    }
381  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
382    if (FrameInfo->isSpillSlotObjectIndex(FI))
383      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
384  }
385
386  // Check for spill-induced copies
387  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
388  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
389                                     SrcSubIdx, DstSubIdx)) {
390    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
391      CommentOS << " Reload Reuse\n";
392  }
393}
394
395
396
397/// EmitFunctionBody - This method emits the body and trailer for a
398/// function.
399void AsmPrinter::EmitFunctionBody() {
400  // Emit target-specific gunk before the function body.
401  EmitFunctionBodyStart();
402
403  // Print out code for the function.
404  bool HasAnyRealCode = false;
405  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
406       I != E; ++I) {
407    // Print a label for the basic block.
408    EmitBasicBlockStart(I);
409    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
410         II != IE; ++II) {
411      // Print the assembly for the instruction.
412      if (!II->isLabel())
413        HasAnyRealCode = true;
414
415      ++EmittedInsts;
416
417      // FIXME: Clean up processDebugLoc.
418      processDebugLoc(II, true);
419
420      if (VerboseAsm)
421        EmitComments(*II, OutStreamer.GetCommentOS());
422
423      switch (II->getOpcode()) {
424      case TargetOpcode::DBG_LABEL:
425      case TargetOpcode::EH_LABEL:
426      case TargetOpcode::GC_LABEL:
427        printLabelInst(II);
428        break;
429      case TargetOpcode::INLINEASM:
430        printInlineAsm(II);
431        break;
432      case TargetOpcode::IMPLICIT_DEF:
433        printImplicitDef(II);
434        break;
435      case TargetOpcode::KILL:
436        printKill(II);
437        break;
438      default:
439        EmitInstruction(II);
440        break;
441      }
442
443      // FIXME: Clean up processDebugLoc.
444      processDebugLoc(II, false);
445    }
446  }
447
448  // If the function is empty and the object file uses .subsections_via_symbols,
449  // then we need to emit *something* to the function body to prevent the
450  // labels from collapsing together.  Just emit a 0 byte.
451  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
452    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
453
454  // Emit target-specific gunk after the function body.
455  EmitFunctionBodyEnd();
456
457  if (MAI->hasDotTypeDotSizeDirective())
458    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
459
460  // Emit post-function debug information.
461  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
462    DW->EndFunction(MF);
463
464  // Print out jump tables referenced by the function.
465  EmitJumpTableInfo();
466
467  OutStreamer.AddBlankLine();
468}
469
470
471bool AsmPrinter::doFinalization(Module &M) {
472  // Emit global variables.
473  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
474       I != E; ++I)
475    EmitGlobalVariable(I);
476
477  // Emit final debug information.
478  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
479    DW->EndModule();
480
481  // If the target wants to know about weak references, print them all.
482  if (MAI->getWeakRefDirective()) {
483    // FIXME: This is not lazy, it would be nice to only print weak references
484    // to stuff that is actually used.  Note that doing so would require targets
485    // to notice uses in operands (due to constant exprs etc).  This should
486    // happen with the MC stuff eventually.
487
488    // Print out module-level global variables here.
489    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
490         I != E; ++I) {
491      if (!I->hasExternalWeakLinkage()) continue;
492      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
493    }
494
495    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
496      if (!I->hasExternalWeakLinkage()) continue;
497      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
498    }
499  }
500
501  if (MAI->hasSetDirective()) {
502    OutStreamer.AddBlankLine();
503    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
504         I != E; ++I) {
505      MCSymbol *Name = Mang->getSymbol(I);
506
507      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
508      MCSymbol *Target = Mang->getSymbol(GV);
509
510      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
511        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
512      else if (I->hasWeakLinkage())
513        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
514      else
515        assert(I->hasLocalLinkage() && "Invalid alias linkage");
516
517      EmitVisibility(Name, I->getVisibility());
518
519      // Emit the directives as assignments aka .set:
520      OutStreamer.EmitAssignment(Name,
521                                 MCSymbolRefExpr::Create(Target, OutContext));
522    }
523  }
524
525  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
526  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
527  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
528    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
529      MP->finishAssembly(O, *this, *MAI);
530
531  // If we don't have any trampolines, then we don't require stack memory
532  // to be executable. Some targets have a directive to declare this.
533  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
534  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
535    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
536      OutStreamer.SwitchSection(S);
537
538  // Allow the target to emit any magic that it wants at the end of the file,
539  // after everything else has gone out.
540  EmitEndOfAsmFile(M);
541
542  delete Mang; Mang = 0;
543  DW = 0; MMI = 0;
544
545  OutStreamer.Finish();
546  return false;
547}
548
549void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
550  this->MF = &MF;
551  // Get the function symbol.
552  CurrentFnSym = Mang->getSymbol(MF.getFunction());
553
554  if (VerboseAsm)
555    LI = &getAnalysis<MachineLoopInfo>();
556}
557
558namespace {
559  // SectionCPs - Keep track the alignment, constpool entries per Section.
560  struct SectionCPs {
561    const MCSection *S;
562    unsigned Alignment;
563    SmallVector<unsigned, 4> CPEs;
564    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
565  };
566}
567
568/// EmitConstantPool - Print to the current output stream assembly
569/// representations of the constants in the constant pool MCP. This is
570/// used to print out constants which have been "spilled to memory" by
571/// the code generator.
572///
573void AsmPrinter::EmitConstantPool() {
574  const MachineConstantPool *MCP = MF->getConstantPool();
575  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
576  if (CP.empty()) return;
577
578  // Calculate sections for constant pool entries. We collect entries to go into
579  // the same section together to reduce amount of section switch statements.
580  SmallVector<SectionCPs, 4> CPSections;
581  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
582    const MachineConstantPoolEntry &CPE = CP[i];
583    unsigned Align = CPE.getAlignment();
584
585    SectionKind Kind;
586    switch (CPE.getRelocationInfo()) {
587    default: llvm_unreachable("Unknown section kind");
588    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
589    case 1:
590      Kind = SectionKind::getReadOnlyWithRelLocal();
591      break;
592    case 0:
593    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
594    case 4:  Kind = SectionKind::getMergeableConst4(); break;
595    case 8:  Kind = SectionKind::getMergeableConst8(); break;
596    case 16: Kind = SectionKind::getMergeableConst16();break;
597    default: Kind = SectionKind::getMergeableConst(); break;
598    }
599    }
600
601    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
602
603    // The number of sections are small, just do a linear search from the
604    // last section to the first.
605    bool Found = false;
606    unsigned SecIdx = CPSections.size();
607    while (SecIdx != 0) {
608      if (CPSections[--SecIdx].S == S) {
609        Found = true;
610        break;
611      }
612    }
613    if (!Found) {
614      SecIdx = CPSections.size();
615      CPSections.push_back(SectionCPs(S, Align));
616    }
617
618    if (Align > CPSections[SecIdx].Alignment)
619      CPSections[SecIdx].Alignment = Align;
620    CPSections[SecIdx].CPEs.push_back(i);
621  }
622
623  // Now print stuff into the calculated sections.
624  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
625    OutStreamer.SwitchSection(CPSections[i].S);
626    EmitAlignment(Log2_32(CPSections[i].Alignment));
627
628    unsigned Offset = 0;
629    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
630      unsigned CPI = CPSections[i].CPEs[j];
631      MachineConstantPoolEntry CPE = CP[CPI];
632
633      // Emit inter-object padding for alignment.
634      unsigned AlignMask = CPE.getAlignment() - 1;
635      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
636      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
637
638      const Type *Ty = CPE.getType();
639      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
640
641      // Emit the label with a comment on it.
642      if (VerboseAsm) {
643        OutStreamer.GetCommentOS() << "constant pool ";
644        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
645                          MF->getFunction()->getParent());
646        OutStreamer.GetCommentOS() << '\n';
647      }
648      OutStreamer.EmitLabel(GetCPISymbol(CPI));
649
650      if (CPE.isMachineConstantPoolEntry())
651        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
652      else
653        EmitGlobalConstant(CPE.Val.ConstVal);
654    }
655  }
656}
657
658/// EmitJumpTableInfo - Print assembly representations of the jump tables used
659/// by the current function to the current output stream.
660///
661void AsmPrinter::EmitJumpTableInfo() {
662  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
663  if (MJTI == 0) return;
664  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
665  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
666  if (JT.empty()) return;
667
668  // Pick the directive to use to print the jump table entries, and switch to
669  // the appropriate section.
670  const Function *F = MF->getFunction();
671  bool JTInDiffSection = false;
672  if (// In PIC mode, we need to emit the jump table to the same section as the
673      // function body itself, otherwise the label differences won't make sense.
674      // FIXME: Need a better predicate for this: what about custom entries?
675      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
676      // We should also do if the section name is NULL or function is declared
677      // in discardable section
678      // FIXME: this isn't the right predicate, should be based on the MCSection
679      // for the function.
680      F->isWeakForLinker()) {
681    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
682  } else {
683    // Otherwise, drop it in the readonly section.
684    const MCSection *ReadOnlySection =
685      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
686    OutStreamer.SwitchSection(ReadOnlySection);
687    JTInDiffSection = true;
688  }
689
690  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
691
692  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
693    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
694
695    // If this jump table was deleted, ignore it.
696    if (JTBBs.empty()) continue;
697
698    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
699    // .set directive for each unique entry.  This reduces the number of
700    // relocations the assembler will generate for the jump table.
701    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
702        MAI->hasSetDirective()) {
703      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
704      const TargetLowering *TLI = TM.getTargetLowering();
705      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
706      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
707        const MachineBasicBlock *MBB = JTBBs[ii];
708        if (!EmittedSets.insert(MBB)) continue;
709
710        // .set LJTSet, LBB32-base
711        const MCExpr *LHS =
712          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
713        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
714                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
715      }
716    }
717
718    // On some targets (e.g. Darwin) we want to emit two consequtive labels
719    // before each jump table.  The first label is never referenced, but tells
720    // the assembler and linker the extents of the jump table object.  The
721    // second label is actually referenced by the code.
722    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
723      // FIXME: This doesn't have to have any specific name, just any randomly
724      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
725      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
726
727    OutStreamer.EmitLabel(GetJTISymbol(JTI));
728
729    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
730      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
731  }
732}
733
734/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
735/// current stream.
736void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
737                                    const MachineBasicBlock *MBB,
738                                    unsigned UID) const {
739  const MCExpr *Value = 0;
740  switch (MJTI->getEntryKind()) {
741  case MachineJumpTableInfo::EK_Inline:
742    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
743  case MachineJumpTableInfo::EK_Custom32:
744    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
745                                                              OutContext);
746    break;
747  case MachineJumpTableInfo::EK_BlockAddress:
748    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
749    //     .word LBB123
750    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
751    break;
752  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
753    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
754    // with a relocation as gp-relative, e.g.:
755    //     .gprel32 LBB123
756    MCSymbol *MBBSym = MBB->getSymbol();
757    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
758    return;
759  }
760
761  case MachineJumpTableInfo::EK_LabelDifference32: {
762    // EK_LabelDifference32 - Each entry is the address of the block minus
763    // the address of the jump table.  This is used for PIC jump tables where
764    // gprel32 is not supported.  e.g.:
765    //      .word LBB123 - LJTI1_2
766    // If the .set directive is supported, this is emitted as:
767    //      .set L4_5_set_123, LBB123 - LJTI1_2
768    //      .word L4_5_set_123
769
770    // If we have emitted set directives for the jump table entries, print
771    // them rather than the entries themselves.  If we're emitting PIC, then
772    // emit the table entries as differences between two text section labels.
773    if (MAI->hasSetDirective()) {
774      // If we used .set, reference the .set's symbol.
775      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
776                                      OutContext);
777      break;
778    }
779    // Otherwise, use the difference as the jump table entry.
780    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
781    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
782    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
783    break;
784  }
785  }
786
787  assert(Value && "Unknown entry kind!");
788
789  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
790  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
791}
792
793
794/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
795/// special global used by LLVM.  If so, emit it and return true, otherwise
796/// do nothing and return false.
797bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
798  if (GV->getName() == "llvm.used") {
799    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
800      EmitLLVMUsedList(GV->getInitializer());
801    return true;
802  }
803
804  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
805  if (GV->getSection() == "llvm.metadata" ||
806      GV->hasAvailableExternallyLinkage())
807    return true;
808
809  if (!GV->hasAppendingLinkage()) return false;
810
811  assert(GV->hasInitializer() && "Not a special LLVM global!");
812
813  const TargetData *TD = TM.getTargetData();
814  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
815  if (GV->getName() == "llvm.global_ctors") {
816    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
817    EmitAlignment(Align, 0);
818    EmitXXStructorList(GV->getInitializer());
819
820    if (TM.getRelocationModel() == Reloc::Static &&
821        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
822      StringRef Sym(".constructors_used");
823      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
824                                      MCSA_Reference);
825    }
826    return true;
827  }
828
829  if (GV->getName() == "llvm.global_dtors") {
830    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
831    EmitAlignment(Align, 0);
832    EmitXXStructorList(GV->getInitializer());
833
834    if (TM.getRelocationModel() == Reloc::Static &&
835        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
836      StringRef Sym(".destructors_used");
837      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
838                                      MCSA_Reference);
839    }
840    return true;
841  }
842
843  return false;
844}
845
846/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
847/// global in the specified llvm.used list for which emitUsedDirectiveFor
848/// is true, as being used with this directive.
849void AsmPrinter::EmitLLVMUsedList(Constant *List) {
850  // Should be an array of 'i8*'.
851  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
852  if (InitList == 0) return;
853
854  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
855    const GlobalValue *GV =
856      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
857    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
858      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
859  }
860}
861
862/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
863/// function pointers, ignoring the init priority.
864void AsmPrinter::EmitXXStructorList(Constant *List) {
865  // Should be an array of '{ int, void ()* }' structs.  The first value is the
866  // init priority, which we ignore.
867  if (!isa<ConstantArray>(List)) return;
868  ConstantArray *InitList = cast<ConstantArray>(List);
869  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
870    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
871      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
872
873      if (CS->getOperand(1)->isNullValue())
874        return;  // Found a null terminator, exit printing.
875      // Emit the function pointer.
876      EmitGlobalConstant(CS->getOperand(1));
877    }
878}
879
880/// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
881void AsmPrinter::EmitInlineAsm(StringRef Str) {
882  assert(!Str.empty() && "Can't emit empty inline asm block");
883
884  // If the output streamer is actually a .s file, just emit the blob textually.
885  // This is useful in case the asm parser doesn't handle something but the
886  // system assembler does.
887  if (OutStreamer.hasRawTextSupport()) {
888    OutStreamer.EmitRawText(Str);
889    return;
890  }
891
892  errs() << "Inline asm not supported by this streamer!\n";
893}
894
895
896//===--------------------------------------------------------------------===//
897// Emission and print routines
898//
899
900/// EmitInt8 - Emit a byte directive and value.
901///
902void AsmPrinter::EmitInt8(int Value) const {
903  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
904}
905
906/// EmitInt16 - Emit a short directive and value.
907///
908void AsmPrinter::EmitInt16(int Value) const {
909  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
910}
911
912/// EmitInt32 - Emit a long directive and value.
913///
914void AsmPrinter::EmitInt32(int Value) const {
915  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
916}
917
918/// EmitInt64 - Emit a long long directive and value.
919///
920void AsmPrinter::EmitInt64(uint64_t Value) const {
921  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
922}
923
924/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
925/// in bytes of the directive is specified by Size and Hi/Lo specify the
926/// labels.  This implicitly uses .set if it is available.
927void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
928                                     unsigned Size) const {
929  // Get the Hi-Lo expression.
930  const MCExpr *Diff =
931    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
932                            MCSymbolRefExpr::Create(Lo, OutContext),
933                            OutContext);
934
935  if (!MAI->hasSetDirective()) {
936    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
937    return;
938  }
939
940  // Otherwise, emit with .set (aka assignment).
941  MCSymbol *SetLabel =
942    OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
943                                 "set" + Twine(SetCounter++));
944  OutStreamer.EmitAssignment(SetLabel, Diff);
945  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
946}
947
948
949//===----------------------------------------------------------------------===//
950
951// EmitAlignment - Emit an alignment directive to the specified power of
952// two boundary.  For example, if you pass in 3 here, you will get an 8
953// byte alignment.  If a global value is specified, and if that global has
954// an explicit alignment requested, it will unconditionally override the
955// alignment request.  However, if ForcedAlignBits is specified, this value
956// has final say: the ultimate alignment will be the max of ForcedAlignBits
957// and the alignment computed with NumBits and the global.
958//
959// The algorithm is:
960//     Align = NumBits;
961//     if (GV && GV->hasalignment) Align = GV->getalignment();
962//     Align = std::max(Align, ForcedAlignBits);
963//
964void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
965                               unsigned ForcedAlignBits,
966                               bool UseFillExpr) const {
967  if (GV && GV->getAlignment())
968    NumBits = Log2_32(GV->getAlignment());
969  NumBits = std::max(NumBits, ForcedAlignBits);
970
971  if (NumBits == 0) return;   // No need to emit alignment.
972
973  if (getCurrentSection()->getKind().isText())
974    OutStreamer.EmitCodeAlignment(1 << NumBits);
975  else
976    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
977}
978
979/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
980///
981static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
982  MCContext &Ctx = AP.OutContext;
983
984  if (CV->isNullValue() || isa<UndefValue>(CV))
985    return MCConstantExpr::Create(0, Ctx);
986
987  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
988    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
989
990  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
991    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
992  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
993    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
994
995  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
996  if (CE == 0) {
997    llvm_unreachable("Unknown constant value to lower!");
998    return MCConstantExpr::Create(0, Ctx);
999  }
1000
1001  switch (CE->getOpcode()) {
1002  default:
1003    // If the code isn't optimized, there may be outstanding folding
1004    // opportunities. Attempt to fold the expression using TargetData as a
1005    // last resort before giving up.
1006    if (Constant *C =
1007          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1008      if (C != CE)
1009        return LowerConstant(C, AP);
1010#ifndef NDEBUG
1011    CE->dump();
1012#endif
1013    llvm_unreachable("FIXME: Don't support this constant expr");
1014  case Instruction::GetElementPtr: {
1015    const TargetData &TD = *AP.TM.getTargetData();
1016    // Generate a symbolic expression for the byte address
1017    const Constant *PtrVal = CE->getOperand(0);
1018    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1019    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1020                                         IdxVec.size());
1021
1022    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1023    if (Offset == 0)
1024      return Base;
1025
1026    // Truncate/sext the offset to the pointer size.
1027    if (TD.getPointerSizeInBits() != 64) {
1028      int SExtAmount = 64-TD.getPointerSizeInBits();
1029      Offset = (Offset << SExtAmount) >> SExtAmount;
1030    }
1031
1032    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1033                                   Ctx);
1034  }
1035
1036  case Instruction::Trunc:
1037    // We emit the value and depend on the assembler to truncate the generated
1038    // expression properly.  This is important for differences between
1039    // blockaddress labels.  Since the two labels are in the same function, it
1040    // is reasonable to treat their delta as a 32-bit value.
1041    // FALL THROUGH.
1042  case Instruction::BitCast:
1043    return LowerConstant(CE->getOperand(0), AP);
1044
1045  case Instruction::IntToPtr: {
1046    const TargetData &TD = *AP.TM.getTargetData();
1047    // Handle casts to pointers by changing them into casts to the appropriate
1048    // integer type.  This promotes constant folding and simplifies this code.
1049    Constant *Op = CE->getOperand(0);
1050    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1051                                      false/*ZExt*/);
1052    return LowerConstant(Op, AP);
1053  }
1054
1055  case Instruction::PtrToInt: {
1056    const TargetData &TD = *AP.TM.getTargetData();
1057    // Support only foldable casts to/from pointers that can be eliminated by
1058    // changing the pointer to the appropriately sized integer type.
1059    Constant *Op = CE->getOperand(0);
1060    const Type *Ty = CE->getType();
1061
1062    const MCExpr *OpExpr = LowerConstant(Op, AP);
1063
1064    // We can emit the pointer value into this slot if the slot is an
1065    // integer slot equal to the size of the pointer.
1066    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1067      return OpExpr;
1068
1069    // Otherwise the pointer is smaller than the resultant integer, mask off
1070    // the high bits so we are sure to get a proper truncation if the input is
1071    // a constant expr.
1072    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1073    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1074    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1075  }
1076
1077  // The MC library also has a right-shift operator, but it isn't consistently
1078  // signed or unsigned between different targets.
1079  case Instruction::Add:
1080  case Instruction::Sub:
1081  case Instruction::Mul:
1082  case Instruction::SDiv:
1083  case Instruction::SRem:
1084  case Instruction::Shl:
1085  case Instruction::And:
1086  case Instruction::Or:
1087  case Instruction::Xor: {
1088    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1089    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1090    switch (CE->getOpcode()) {
1091    default: llvm_unreachable("Unknown binary operator constant cast expr");
1092    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1093    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1094    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1095    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1096    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1097    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1098    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1099    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1100    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1101    }
1102  }
1103  }
1104}
1105
1106static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1107                                    AsmPrinter &AP) {
1108  if (AddrSpace != 0 || !CA->isString()) {
1109    // Not a string.  Print the values in successive locations
1110    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1111      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1112    return;
1113  }
1114
1115  // Otherwise, it can be emitted as .ascii.
1116  SmallVector<char, 128> TmpVec;
1117  TmpVec.reserve(CA->getNumOperands());
1118  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1119    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1120
1121  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1122}
1123
1124static void EmitGlobalConstantVector(const ConstantVector *CV,
1125                                     unsigned AddrSpace, AsmPrinter &AP) {
1126  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1127    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1128}
1129
1130static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1131                                     unsigned AddrSpace, AsmPrinter &AP) {
1132  // Print the fields in successive locations. Pad to align if needed!
1133  const TargetData *TD = AP.TM.getTargetData();
1134  unsigned Size = TD->getTypeAllocSize(CS->getType());
1135  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1136  uint64_t SizeSoFar = 0;
1137  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1138    const Constant *Field = CS->getOperand(i);
1139
1140    // Check if padding is needed and insert one or more 0s.
1141    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1142    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1143                        - Layout->getElementOffset(i)) - FieldSize;
1144    SizeSoFar += FieldSize + PadSize;
1145
1146    // Now print the actual field value.
1147    AP.EmitGlobalConstant(Field, AddrSpace);
1148
1149    // Insert padding - this may include padding to increase the size of the
1150    // current field up to the ABI size (if the struct is not packed) as well
1151    // as padding to ensure that the next field starts at the right offset.
1152    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1153  }
1154  assert(SizeSoFar == Layout->getSizeInBytes() &&
1155         "Layout of constant struct may be incorrect!");
1156}
1157
1158static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1159                                    unsigned AddrSpace, AsmPrinter &AP) {
1160  const TargetData *TD = AP.TM.getTargetData();
1161  unsigned Size = TD->getTypeAllocSize(CU->getType());
1162
1163  const Constant *Contents = CU->getOperand(0);
1164  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1165
1166  // Print the actually filled part
1167  AP.EmitGlobalConstant(Contents, AddrSpace);
1168
1169  // And pad with enough zeroes
1170  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1171}
1172
1173static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1174                                 AsmPrinter &AP) {
1175  // FP Constants are printed as integer constants to avoid losing
1176  // precision.
1177  if (CFP->getType()->isDoubleTy()) {
1178    if (AP.VerboseAsm) {
1179      double Val = CFP->getValueAPF().convertToDouble();
1180      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1181    }
1182
1183    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1184    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1185    return;
1186  }
1187
1188  if (CFP->getType()->isFloatTy()) {
1189    if (AP.VerboseAsm) {
1190      float Val = CFP->getValueAPF().convertToFloat();
1191      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1192    }
1193    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1194    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1195    return;
1196  }
1197
1198  if (CFP->getType()->isX86_FP80Ty()) {
1199    // all long double variants are printed as hex
1200    // api needed to prevent premature destruction
1201    APInt API = CFP->getValueAPF().bitcastToAPInt();
1202    const uint64_t *p = API.getRawData();
1203    if (AP.VerboseAsm) {
1204      // Convert to double so we can print the approximate val as a comment.
1205      APFloat DoubleVal = CFP->getValueAPF();
1206      bool ignored;
1207      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1208                        &ignored);
1209      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1210        << DoubleVal.convertToDouble() << '\n';
1211    }
1212
1213    if (AP.TM.getTargetData()->isBigEndian()) {
1214      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1215      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1216    } else {
1217      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1218      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1219    }
1220
1221    // Emit the tail padding for the long double.
1222    const TargetData &TD = *AP.TM.getTargetData();
1223    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1224                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1225    return;
1226  }
1227
1228  assert(CFP->getType()->isPPC_FP128Ty() &&
1229         "Floating point constant type not handled");
1230  // All long double variants are printed as hex api needed to prevent
1231  // premature destruction.
1232  APInt API = CFP->getValueAPF().bitcastToAPInt();
1233  const uint64_t *p = API.getRawData();
1234  if (AP.TM.getTargetData()->isBigEndian()) {
1235    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1236    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1237  } else {
1238    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1239    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1240  }
1241}
1242
1243static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1244                                       unsigned AddrSpace, AsmPrinter &AP) {
1245  const TargetData *TD = AP.TM.getTargetData();
1246  unsigned BitWidth = CI->getBitWidth();
1247  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1248
1249  // We don't expect assemblers to support integer data directives
1250  // for more than 64 bits, so we emit the data in at most 64-bit
1251  // quantities at a time.
1252  const uint64_t *RawData = CI->getValue().getRawData();
1253  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1254    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1255    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1256  }
1257}
1258
1259/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1260void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1261  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1262    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1263    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1264    return OutStreamer.EmitZeros(Size, AddrSpace);
1265  }
1266
1267  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1268    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1269    switch (Size) {
1270    case 1:
1271    case 2:
1272    case 4:
1273    case 8:
1274      if (VerboseAsm)
1275        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1276      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1277      return;
1278    default:
1279      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1280      return;
1281    }
1282  }
1283
1284  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1285    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1286
1287  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1288    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1289
1290  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1291    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1292
1293  if (isa<ConstantPointerNull>(CV)) {
1294    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1295    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1296    return;
1297  }
1298
1299  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1300    return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1301
1302  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1303    return EmitGlobalConstantVector(V, AddrSpace, *this);
1304
1305  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1306  // thread the streamer with EmitValue.
1307  OutStreamer.EmitValue(LowerConstant(CV, *this),
1308                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1309                        AddrSpace);
1310}
1311
1312void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1313  // Target doesn't support this yet!
1314  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1315}
1316
1317/// PrintSpecial - Print information related to the specified machine instr
1318/// that is independent of the operand, and may be independent of the instr
1319/// itself.  This can be useful for portably encoding the comment character
1320/// or other bits of target-specific knowledge into the asmstrings.  The
1321/// syntax used is ${:comment}.  Targets can override this to add support
1322/// for their own strange codes.
1323void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1324  if (!strcmp(Code, "private")) {
1325    O << MAI->getPrivateGlobalPrefix();
1326  } else if (!strcmp(Code, "comment")) {
1327    if (VerboseAsm)
1328      O << MAI->getCommentString();
1329  } else if (!strcmp(Code, "uid")) {
1330    // Comparing the address of MI isn't sufficient, because machineinstrs may
1331    // be allocated to the same address across functions.
1332    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1333
1334    // If this is a new LastFn instruction, bump the counter.
1335    if (LastMI != MI || LastFn != ThisF) {
1336      ++Counter;
1337      LastMI = MI;
1338      LastFn = ThisF;
1339    }
1340    O << Counter;
1341  } else {
1342    std::string msg;
1343    raw_string_ostream Msg(msg);
1344    Msg << "Unknown special formatter '" << Code
1345         << "' for machine instr: " << *MI;
1346    llvm_report_error(Msg.str());
1347  }
1348}
1349
1350/// processDebugLoc - Processes the debug information of each machine
1351/// instruction's DebugLoc.
1352void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1353                                 bool BeforePrintingInsn) {
1354  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1355      || !DW->ShouldEmitDwarfDebug())
1356    return;
1357
1358  if (!BeforePrintingInsn)
1359    // After printing instruction
1360    DW->EndScope(MI);
1361  else
1362    DW->BeginScope(MI);
1363}
1364
1365
1366/// printInlineAsm - This method formats and prints the specified machine
1367/// instruction that is an inline asm.
1368void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1369  unsigned NumOperands = MI->getNumOperands();
1370
1371  // Count the number of register definitions.
1372  unsigned NumDefs = 0;
1373  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1374       ++NumDefs)
1375    assert(NumDefs != NumOperands-1 && "No asm string?");
1376
1377  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1378
1379  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1380  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1381
1382  O << '\t';
1383
1384  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1385  // These are useful to see where empty asm's wound up.
1386  if (AsmStr[0] == 0) {
1387    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1388    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1389    return;
1390  }
1391
1392  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1393
1394  // The variant of the current asmprinter.
1395  int AsmPrinterVariant = MAI->getAssemblerDialect();
1396
1397  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1398  const char *LastEmitted = AsmStr; // One past the last character emitted.
1399
1400  while (*LastEmitted) {
1401    switch (*LastEmitted) {
1402    default: {
1403      // Not a special case, emit the string section literally.
1404      const char *LiteralEnd = LastEmitted+1;
1405      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1406             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1407        ++LiteralEnd;
1408      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1409        O.write(LastEmitted, LiteralEnd-LastEmitted);
1410      LastEmitted = LiteralEnd;
1411      break;
1412    }
1413    case '\n':
1414      ++LastEmitted;   // Consume newline character.
1415      O << '\n';       // Indent code with newline.
1416      break;
1417    case '$': {
1418      ++LastEmitted;   // Consume '$' character.
1419      bool Done = true;
1420
1421      // Handle escapes.
1422      switch (*LastEmitted) {
1423      default: Done = false; break;
1424      case '$':     // $$ -> $
1425        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1426          O << '$';
1427        ++LastEmitted;  // Consume second '$' character.
1428        break;
1429      case '(':             // $( -> same as GCC's { character.
1430        ++LastEmitted;      // Consume '(' character.
1431        if (CurVariant != -1) {
1432          llvm_report_error("Nested variants found in inline asm string: '"
1433                            + std::string(AsmStr) + "'");
1434        }
1435        CurVariant = 0;     // We're in the first variant now.
1436        break;
1437      case '|':
1438        ++LastEmitted;  // consume '|' character.
1439        if (CurVariant == -1)
1440          O << '|';       // this is gcc's behavior for | outside a variant
1441        else
1442          ++CurVariant;   // We're in the next variant.
1443        break;
1444      case ')':         // $) -> same as GCC's } char.
1445        ++LastEmitted;  // consume ')' character.
1446        if (CurVariant == -1)
1447          O << '}';     // this is gcc's behavior for } outside a variant
1448        else
1449          CurVariant = -1;
1450        break;
1451      }
1452      if (Done) break;
1453
1454      bool HasCurlyBraces = false;
1455      if (*LastEmitted == '{') {     // ${variable}
1456        ++LastEmitted;               // Consume '{' character.
1457        HasCurlyBraces = true;
1458      }
1459
1460      // If we have ${:foo}, then this is not a real operand reference, it is a
1461      // "magic" string reference, just like in .td files.  Arrange to call
1462      // PrintSpecial.
1463      if (HasCurlyBraces && *LastEmitted == ':') {
1464        ++LastEmitted;
1465        const char *StrStart = LastEmitted;
1466        const char *StrEnd = strchr(StrStart, '}');
1467        if (StrEnd == 0) {
1468          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1469                            + std::string(AsmStr) + "'");
1470        }
1471
1472        std::string Val(StrStart, StrEnd);
1473        PrintSpecial(MI, Val.c_str());
1474        LastEmitted = StrEnd+1;
1475        break;
1476      }
1477
1478      const char *IDStart = LastEmitted;
1479      char *IDEnd;
1480      errno = 0;
1481      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1482      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1483        llvm_report_error("Bad $ operand number in inline asm string: '"
1484                          + std::string(AsmStr) + "'");
1485      }
1486      LastEmitted = IDEnd;
1487
1488      char Modifier[2] = { 0, 0 };
1489
1490      if (HasCurlyBraces) {
1491        // If we have curly braces, check for a modifier character.  This
1492        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1493        if (*LastEmitted == ':') {
1494          ++LastEmitted;    // Consume ':' character.
1495          if (*LastEmitted == 0) {
1496            llvm_report_error("Bad ${:} expression in inline asm string: '"
1497                              + std::string(AsmStr) + "'");
1498          }
1499
1500          Modifier[0] = *LastEmitted;
1501          ++LastEmitted;    // Consume modifier character.
1502        }
1503
1504        if (*LastEmitted != '}') {
1505          llvm_report_error("Bad ${} expression in inline asm string: '"
1506                            + std::string(AsmStr) + "'");
1507        }
1508        ++LastEmitted;    // Consume '}' character.
1509      }
1510
1511      if ((unsigned)Val >= NumOperands-1) {
1512        llvm_report_error("Invalid $ operand number in inline asm string: '"
1513                          + std::string(AsmStr) + "'");
1514      }
1515
1516      // Okay, we finally have a value number.  Ask the target to print this
1517      // operand!
1518      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1519        unsigned OpNo = 1;
1520
1521        bool Error = false;
1522
1523        // Scan to find the machine operand number for the operand.
1524        for (; Val; --Val) {
1525          if (OpNo >= MI->getNumOperands()) break;
1526          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1527          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1528        }
1529
1530        if (OpNo >= MI->getNumOperands()) {
1531          Error = true;
1532        } else {
1533          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1534          ++OpNo;  // Skip over the ID number.
1535
1536          if (Modifier[0] == 'l')  // labels are target independent
1537            O << *MI->getOperand(OpNo).getMBB()->getSymbol();
1538          else {
1539            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1540            if ((OpFlags & 7) == 4) {
1541              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1542                                                Modifier[0] ? Modifier : 0);
1543            } else {
1544              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1545                                          Modifier[0] ? Modifier : 0);
1546            }
1547          }
1548        }
1549        if (Error) {
1550          std::string msg;
1551          raw_string_ostream Msg(msg);
1552          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1553          MI->print(Msg);
1554          llvm_report_error(Msg.str());
1555        }
1556      }
1557      break;
1558    }
1559    }
1560  }
1561  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1562  OutStreamer.AddBlankLine();
1563}
1564
1565/// printImplicitDef - This method prints the specified machine instruction
1566/// that is an implicit def.
1567void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1568  if (!VerboseAsm) return;
1569  O.PadToColumn(MAI->getCommentColumn());
1570  O << MAI->getCommentString() << " implicit-def: "
1571    << TRI->getName(MI->getOperand(0).getReg());
1572  OutStreamer.AddBlankLine();
1573}
1574
1575void AsmPrinter::printKill(const MachineInstr *MI) const {
1576  if (!VerboseAsm) return;
1577  O.PadToColumn(MAI->getCommentColumn());
1578  O << MAI->getCommentString() << " kill:";
1579  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1580    const MachineOperand &op = MI->getOperand(n);
1581    assert(op.isReg() && "KILL instruction must have only register operands");
1582    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1583  }
1584  OutStreamer.AddBlankLine();
1585}
1586
1587/// printLabel - This method prints a local label used by debug and
1588/// exception handling tables.
1589void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1590  OutStreamer.EmitLabel(MI->getOperand(0).getMCSymbol());
1591}
1592
1593/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1594/// instruction, using the specified assembler variant.  Targets should
1595/// override this to format as appropriate.
1596bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1597                                 unsigned AsmVariant, const char *ExtraCode) {
1598  // Target doesn't support this yet!
1599  return true;
1600}
1601
1602bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1603                                       unsigned AsmVariant,
1604                                       const char *ExtraCode) {
1605  // Target doesn't support this yet!
1606  return true;
1607}
1608
1609MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1610  return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1611}
1612
1613MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1614  return MMI->getAddrLabelSymbol(BB);
1615}
1616
1617/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1618MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1619  return OutContext.GetOrCreateSymbol
1620    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1621     + "_" + Twine(CPID));
1622}
1623
1624/// GetJTISymbol - Return the symbol for the specified jump table entry.
1625MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1626  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1627}
1628
1629/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1630/// FIXME: privatize to AsmPrinter.
1631MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1632  return OutContext.GetOrCreateSymbol
1633  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1634   Twine(UID) + "_set_" + Twine(MBBID));
1635}
1636
1637/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1638/// global value name as its base, with the specified suffix, and where the
1639/// symbol is forced to have private linkage if ForcePrivate is true.
1640MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1641                                                   StringRef Suffix,
1642                                                   bool ForcePrivate) const {
1643  SmallString<60> NameStr;
1644  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1645  NameStr.append(Suffix.begin(), Suffix.end());
1646  return OutContext.GetOrCreateSymbol(NameStr.str());
1647}
1648
1649/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1650/// ExternalSymbol.
1651MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1652  SmallString<60> NameStr;
1653  Mang->getNameWithPrefix(NameStr, Sym);
1654  return OutContext.GetOrCreateSymbol(NameStr.str());
1655}
1656
1657
1658
1659/// PrintParentLoopComment - Print comments about parent loops of this one.
1660static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1661                                   unsigned FunctionNumber) {
1662  if (Loop == 0) return;
1663  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1664  OS.indent(Loop->getLoopDepth()*2)
1665    << "Parent Loop BB" << FunctionNumber << "_"
1666    << Loop->getHeader()->getNumber()
1667    << " Depth=" << Loop->getLoopDepth() << '\n';
1668}
1669
1670
1671/// PrintChildLoopComment - Print comments about child loops within
1672/// the loop for this basic block, with nesting.
1673static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1674                                  unsigned FunctionNumber) {
1675  // Add child loop information
1676  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1677    OS.indent((*CL)->getLoopDepth()*2)
1678      << "Child Loop BB" << FunctionNumber << "_"
1679      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1680      << '\n';
1681    PrintChildLoopComment(OS, *CL, FunctionNumber);
1682  }
1683}
1684
1685/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1686static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1687                                        const MachineLoopInfo *LI,
1688                                        const AsmPrinter &AP) {
1689  // Add loop depth information
1690  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1691  if (Loop == 0) return;
1692
1693  MachineBasicBlock *Header = Loop->getHeader();
1694  assert(Header && "No header for loop");
1695
1696  // If this block is not a loop header, just print out what is the loop header
1697  // and return.
1698  if (Header != &MBB) {
1699    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1700                              Twine(AP.getFunctionNumber())+"_" +
1701                              Twine(Loop->getHeader()->getNumber())+
1702                              " Depth="+Twine(Loop->getLoopDepth()));
1703    return;
1704  }
1705
1706  // Otherwise, it is a loop header.  Print out information about child and
1707  // parent loops.
1708  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1709
1710  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1711
1712  OS << "=>";
1713  OS.indent(Loop->getLoopDepth()*2-2);
1714
1715  OS << "This ";
1716  if (Loop->empty())
1717    OS << "Inner ";
1718  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1719
1720  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1721}
1722
1723
1724/// EmitBasicBlockStart - This method prints the label for the specified
1725/// MachineBasicBlock, an alignment (if present) and a comment describing
1726/// it if appropriate.
1727void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1728  // Emit an alignment directive for this block, if needed.
1729  if (unsigned Align = MBB->getAlignment())
1730    EmitAlignment(Log2_32(Align));
1731
1732  // If the block has its address taken, emit any labels that were used to
1733  // reference the block.  It is possible that there is more than one label
1734  // here, because multiple LLVM BB's may have been RAUW'd to this block after
1735  // the references were generated.
1736  if (MBB->hasAddressTaken()) {
1737    const BasicBlock *BB = MBB->getBasicBlock();
1738    if (VerboseAsm)
1739      OutStreamer.AddComment("Block address taken");
1740
1741    std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1742
1743    for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1744      OutStreamer.EmitLabel(Syms[i]);
1745  }
1746
1747  // Print the main label for the block.
1748  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1749    if (VerboseAsm) {
1750      // NOTE: Want this comment at start of line.
1751      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1752      if (const BasicBlock *BB = MBB->getBasicBlock())
1753        if (BB->hasName())
1754          OutStreamer.AddComment("%" + BB->getName());
1755
1756      PrintBasicBlockLoopComments(*MBB, LI, *this);
1757      OutStreamer.AddBlankLine();
1758    }
1759  } else {
1760    if (VerboseAsm) {
1761      if (const BasicBlock *BB = MBB->getBasicBlock())
1762        if (BB->hasName())
1763          OutStreamer.AddComment("%" + BB->getName());
1764      PrintBasicBlockLoopComments(*MBB, LI, *this);
1765    }
1766
1767    OutStreamer.EmitLabel(MBB->getSymbol());
1768  }
1769}
1770
1771void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1772  MCSymbolAttr Attr = MCSA_Invalid;
1773
1774  switch (Visibility) {
1775  default: break;
1776  case GlobalValue::HiddenVisibility:
1777    Attr = MAI->getHiddenVisibilityAttr();
1778    break;
1779  case GlobalValue::ProtectedVisibility:
1780    Attr = MAI->getProtectedVisibilityAttr();
1781    break;
1782  }
1783
1784  if (Attr != MCSA_Invalid)
1785    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1786}
1787
1788void AsmPrinter::printOffset(int64_t Offset) const {
1789  if (Offset > 0)
1790    O << '+' << Offset;
1791  else if (Offset < 0)
1792    O << Offset;
1793}
1794
1795/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1796/// exactly one predecessor and the control transfer mechanism between
1797/// the predecessor and this block is a fall-through.
1798bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1799    const {
1800  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1801  // then nothing falls through to it.
1802  if (MBB->isLandingPad() || MBB->pred_empty())
1803    return false;
1804
1805  // If there isn't exactly one predecessor, it can't be a fall through.
1806  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1807  ++PI2;
1808  if (PI2 != MBB->pred_end())
1809    return false;
1810
1811  // The predecessor has to be immediately before this block.
1812  const MachineBasicBlock *Pred = *PI;
1813
1814  if (!Pred->isLayoutSuccessor(MBB))
1815    return false;
1816
1817  // If the block is completely empty, then it definitely does fall through.
1818  if (Pred->empty())
1819    return true;
1820
1821  // Otherwise, check the last instruction.
1822  const MachineInstr &LastInst = Pred->back();
1823  return !LastInst.getDesc().isBarrier();
1824}
1825
1826
1827
1828GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1829  if (!S->usesMetadata())
1830    return 0;
1831
1832  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1833  if (GCPI != GCMetadataPrinters.end())
1834    return GCPI->second;
1835
1836  const char *Name = S->getName().c_str();
1837
1838  for (GCMetadataPrinterRegistry::iterator
1839         I = GCMetadataPrinterRegistry::begin(),
1840         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1841    if (strcmp(Name, I->getName()) == 0) {
1842      GCMetadataPrinter *GMP = I->instantiate();
1843      GMP->S = S;
1844      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1845      return GMP;
1846    }
1847
1848  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1849  return 0;
1850}
1851
1852