AsmPrinter.cpp revision e4454320b3cfffe926a487c33fbeb454366de2f8 
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>
53#include <ctype.h>
54using namespace llvm;
55
56STATISTIC(EmittedInsts, "Number of machine instrs printed");
57
58char AsmPrinter::ID = 0;
59AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
60                       MCContext &Ctx, MCStreamer &Streamer,
61                       const MCAsmInfo *T)
62  : MachineFunctionPass(&ID), O(o),
63    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
64    OutContext(Ctx), OutStreamer(Streamer),
65    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
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  delete &OutContext;
77}
78
79/// getFunctionNumber - Return a unique ID for the current function.
80///
81unsigned AsmPrinter::getFunctionNumber() const {
82  return MF->getFunctionNumber();
83}
84
85TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
86  return TM.getTargetLowering()->getObjFileLowering();
87}
88
89/// getCurrentSection() - Return the current section we are emitting to.
90const MCSection *AsmPrinter::getCurrentSection() const {
91  return OutStreamer.getCurrentSection();
92}
93
94
95void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
96  AU.setPreservesAll();
97  MachineFunctionPass::getAnalysisUsage(AU);
98  AU.addRequired<GCModuleInfo>();
99  if (VerboseAsm)
100    AU.addRequired<MachineLoopInfo>();
101}
102
103bool AsmPrinter::doInitialization(Module &M) {
104  // Initialize TargetLoweringObjectFile.
105  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
106    .Initialize(OutContext, TM);
107
108  Mang = new Mangler(*MAI);
109
110  // Allow the target to emit any magic that it wants at the start of the file.
111  EmitStartOfAsmFile(M);
112
113  // Very minimal debug info. It is ignored if we emit actual debug info. If we
114  // don't, this at least helps the user find where a global came from.
115  if (MAI->hasSingleParameterDotFile()) {
116    // .file "foo.c"
117    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
118  }
119
120  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
121  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
122  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
123    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
124      MP->beginAssembly(O, *this, *MAI);
125
126  if (!M.getModuleInlineAsm().empty())
127    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
128      << M.getModuleInlineAsm()
129      << '\n' << MAI->getCommentString()
130      << " End of file scope inline assembly\n";
131
132  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
133  if (MMI)
134    MMI->AnalyzeModule(M);
135  DW = getAnalysisIfAvailable<DwarfWriter>();
136  if (DW)
137    DW->BeginModule(&M, MMI, O, this, MAI);
138
139  return false;
140}
141
142void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
143  switch ((GlobalValue::LinkageTypes)Linkage) {
144  case GlobalValue::CommonLinkage:
145  case GlobalValue::LinkOnceAnyLinkage:
146  case GlobalValue::LinkOnceODRLinkage:
147  case GlobalValue::WeakAnyLinkage:
148  case GlobalValue::WeakODRLinkage:
149  case GlobalValue::LinkerPrivateLinkage:
150    if (MAI->getWeakDefDirective() != 0) {
151      // .globl _foo
152      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
153      // .weak_definition _foo
154      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
155    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
156      // .globl _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
158      // FIXME: linkonce should be a section attribute, handled by COFF Section
159      // assignment.
160      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
161      // .linkonce discard
162      // FIXME: It would be nice to use .linkonce samesize for non-common
163      // globals.
164      O << LinkOnce;
165    } else {
166      // .weak _foo
167      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
168    }
169    break;
170  case GlobalValue::DLLExportLinkage:
171  case GlobalValue::AppendingLinkage:
172    // FIXME: appending linkage variables should go into a section of
173    // their name or something.  For now, just emit them as external.
174  case GlobalValue::ExternalLinkage:
175    // If external or appending, declare as a global symbol.
176    // .globl _foo
177    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
178    break;
179  case GlobalValue::PrivateLinkage:
180  case GlobalValue::InternalLinkage:
181    break;
182  default:
183    llvm_unreachable("Unknown linkage type!");
184  }
185}
186
187
188/// EmitGlobalVariable - Emit the specified global variable to the .s file.
189void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
190  if (!GV->hasInitializer())   // External globals require no code.
191    return;
192
193  // Check to see if this is a special global used by LLVM, if so, emit it.
194  if (EmitSpecialLLVMGlobal(GV))
195    return;
196
197  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
198  EmitVisibility(GVSym, GV->getVisibility());
199
200  if (MAI->hasDotTypeDotSizeDirective())
201    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
202
203  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
204
205  const TargetData *TD = TM.getTargetData();
206  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
207  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
208
209  // Handle common and BSS local symbols (.lcomm).
210  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
211    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
212
213    if (VerboseAsm) {
214      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
215                     /*PrintType=*/false, GV->getParent());
216      OutStreamer.GetCommentOS() << '\n';
217    }
218
219    // Handle common symbols.
220    if (GVKind.isCommon()) {
221      // .comm _foo, 42, 4
222      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
223      return;
224    }
225
226    // Handle local BSS symbols.
227    if (MAI->hasMachoZeroFillDirective()) {
228      const MCSection *TheSection =
229        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
230      // .zerofill __DATA, __bss, _foo, 400, 5
231      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
232      return;
233    }
234
235    if (MAI->hasLCOMMDirective()) {
236      // .lcomm _foo, 42
237      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
238      return;
239    }
240
241    // .local _foo
242    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
243    // .comm _foo, 42, 4
244    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
245    return;
246  }
247
248  const MCSection *TheSection =
249    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
250
251  // Handle the zerofill directive on darwin, which is a special form of BSS
252  // emission.
253  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
254    // .globl _foo
255    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
256    // .zerofill __DATA, __common, _foo, 400, 5
257    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
258    return;
259  }
260
261  OutStreamer.SwitchSection(TheSection);
262
263  EmitLinkage(GV->getLinkage(), GVSym);
264  EmitAlignment(AlignLog, GV);
265
266  if (VerboseAsm) {
267    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
268                   /*PrintType=*/false, GV->getParent());
269    OutStreamer.GetCommentOS() << '\n';
270  }
271  OutStreamer.EmitLabel(GVSym);
272
273  EmitGlobalConstant(GV->getInitializer());
274
275  if (MAI->hasDotTypeDotSizeDirective())
276    // .size foo, 42
277    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
278
279  OutStreamer.AddBlankLine();
280}
281
282/// EmitFunctionHeader - This method emits the header for the current
283/// function.
284void AsmPrinter::EmitFunctionHeader() {
285  // Print out constants referenced by the function
286  EmitConstantPool();
287
288  // Print the 'header' of function.
289  const Function *F = MF->getFunction();
290
291  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
292  EmitVisibility(CurrentFnSym, F->getVisibility());
293
294  EmitLinkage(F->getLinkage(), CurrentFnSym);
295  EmitAlignment(MF->getAlignment(), F);
296
297  if (MAI->hasDotTypeDotSizeDirective())
298    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
299
300  if (VerboseAsm) {
301    WriteAsOperand(OutStreamer.GetCommentOS(), F,
302                   /*PrintType=*/false, F->getParent());
303    OutStreamer.GetCommentOS() << '\n';
304  }
305
306  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
307  // do their wild and crazy things as required.
308  EmitFunctionEntryLabel();
309
310  // Add some workaround for linkonce linkage on Cygwin\MinGW.
311  if (MAI->getLinkOnceDirective() != 0 &&
312      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
313    // FIXME: What is this?
314    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
315
316  // Emit pre-function debug and/or EH information.
317  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
318    DW->BeginFunction(MF);
319}
320
321/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
322/// function.  This can be overridden by targets as required to do custom stuff.
323void AsmPrinter::EmitFunctionEntryLabel() {
324  OutStreamer.EmitLabel(CurrentFnSym);
325}
326
327
328/// EmitComments - Pretty-print comments for instructions.
329static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
330  const MachineFunction *MF = MI.getParent()->getParent();
331  const TargetMachine &TM = MF->getTarget();
332
333  if (!MI.getDebugLoc().isUnknown()) {
334    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
335
336    // Print source line info.
337    DIScope Scope = DLT.getScope();
338    // Omit the directory, because it's likely to be long and uninteresting.
339    if (!Scope.isNull())
340      CommentOS << Scope.getFilename();
341    else
342      CommentOS << "<unknown>";
343    CommentOS << ':' << DLT.getLineNumber();
344    if (DLT.getColumnNumber() != 0)
345      CommentOS << ':' << DLT.getColumnNumber();
346    CommentOS << '\n';
347  }
348
349  // Check for spills and reloads
350  int FI;
351
352  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
353
354  // We assume a single instruction only has a spill or reload, not
355  // both.
356  const MachineMemOperand *MMO;
357  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
358    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
359      MMO = *MI.memoperands_begin();
360      CommentOS << MMO->getSize() << "-byte Reload\n";
361    }
362  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
363    if (FrameInfo->isSpillSlotObjectIndex(FI))
364      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
365  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
366    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
367      MMO = *MI.memoperands_begin();
368      CommentOS << MMO->getSize() << "-byte Spill\n";
369    }
370  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
371    if (FrameInfo->isSpillSlotObjectIndex(FI))
372      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
373  }
374
375  // Check for spill-induced copies
376  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
377  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
378                                     SrcSubIdx, DstSubIdx)) {
379    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
380      CommentOS << " Reload Reuse\n";
381  }
382}
383
384
385
386/// EmitFunctionBody - This method emits the body and trailer for a
387/// function.
388void AsmPrinter::EmitFunctionBody() {
389  // Emit target-specific gunk before the function body.
390  EmitFunctionBodyStart();
391
392  // Print out code for the function.
393  bool HasAnyRealCode = false;
394  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
395       I != E; ++I) {
396    // Print a label for the basic block.
397    EmitBasicBlockStart(I);
398    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
399         II != IE; ++II) {
400      // Print the assembly for the instruction.
401      if (!II->isLabel())
402        HasAnyRealCode = true;
403
404      ++EmittedInsts;
405
406      // FIXME: Clean up processDebugLoc.
407      processDebugLoc(II, true);
408
409      if (VerboseAsm)
410        EmitComments(*II, OutStreamer.GetCommentOS());
411
412      switch (II->getOpcode()) {
413      case TargetOpcode::DBG_LABEL:
414      case TargetOpcode::EH_LABEL:
415      case TargetOpcode::GC_LABEL:
416        printLabelInst(II);
417        break;
418      case TargetOpcode::INLINEASM:
419        printInlineAsm(II);
420        break;
421      case TargetOpcode::IMPLICIT_DEF:
422        printImplicitDef(II);
423        break;
424      case TargetOpcode::KILL:
425        printKill(II);
426        break;
427      default:
428        EmitInstruction(II);
429        break;
430      }
431
432      // FIXME: Clean up processDebugLoc.
433      processDebugLoc(II, false);
434    }
435  }
436
437  // If the function is empty and the object file uses .subsections_via_symbols,
438  // then we need to emit *something* to the function body to prevent the
439  // labels from collapsing together.  Just emit a 0 byte.
440  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
441    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
442
443  // Emit target-specific gunk after the function body.
444  EmitFunctionBodyEnd();
445
446  if (MAI->hasDotTypeDotSizeDirective())
447    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
448
449  // Emit post-function debug information.
450  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
451    DW->EndFunction(MF);
452
453  // Print out jump tables referenced by the function.
454  EmitJumpTableInfo();
455
456  OutStreamer.AddBlankLine();
457}
458
459
460bool AsmPrinter::doFinalization(Module &M) {
461  // Emit global variables.
462  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
463       I != E; ++I)
464    EmitGlobalVariable(I);
465
466  // Emit final debug information.
467  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
468    DW->EndModule();
469
470  // If the target wants to know about weak references, print them all.
471  if (MAI->getWeakRefDirective()) {
472    // FIXME: This is not lazy, it would be nice to only print weak references
473    // to stuff that is actually used.  Note that doing so would require targets
474    // to notice uses in operands (due to constant exprs etc).  This should
475    // happen with the MC stuff eventually.
476
477    // Print out module-level global variables here.
478    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
479         I != E; ++I) {
480      if (!I->hasExternalWeakLinkage()) continue;
481      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
482                                      MCSA_WeakReference);
483    }
484
485    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
486      if (!I->hasExternalWeakLinkage()) continue;
487      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
488                                      MCSA_WeakReference);
489    }
490  }
491
492  if (MAI->hasSetDirective()) {
493    OutStreamer.AddBlankLine();
494    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
495         I != E; ++I) {
496      MCSymbol *Name = GetGlobalValueSymbol(I);
497
498      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
499      MCSymbol *Target = GetGlobalValueSymbol(GV);
500
501      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
502        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
503      else if (I->hasWeakLinkage())
504        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
505      else
506        assert(I->hasLocalLinkage() && "Invalid alias linkage");
507
508      EmitVisibility(Name, I->getVisibility());
509
510      // Emit the directives as assignments aka .set:
511      OutStreamer.EmitAssignment(Name,
512                                 MCSymbolRefExpr::Create(Target, OutContext));
513    }
514  }
515
516  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
517  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
518  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
519    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
520      MP->finishAssembly(O, *this, *MAI);
521
522  // If we don't have any trampolines, then we don't require stack memory
523  // to be executable. Some targets have a directive to declare this.
524  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
525  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
526    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
527      OutStreamer.SwitchSection(S);
528
529  // Allow the target to emit any magic that it wants at the end of the file,
530  // after everything else has gone out.
531  EmitEndOfAsmFile(M);
532
533  delete Mang; Mang = 0;
534  DW = 0; MMI = 0;
535
536  OutStreamer.Finish();
537  return false;
538}
539
540void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
541  this->MF = &MF;
542  // Get the function symbol.
543  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
544
545  if (VerboseAsm)
546    LI = &getAnalysis<MachineLoopInfo>();
547}
548
549namespace {
550  // SectionCPs - Keep track the alignment, constpool entries per Section.
551  struct SectionCPs {
552    const MCSection *S;
553    unsigned Alignment;
554    SmallVector<unsigned, 4> CPEs;
555    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
556  };
557}
558
559/// EmitConstantPool - Print to the current output stream assembly
560/// representations of the constants in the constant pool MCP. This is
561/// used to print out constants which have been "spilled to memory" by
562/// the code generator.
563///
564void AsmPrinter::EmitConstantPool() {
565  const MachineConstantPool *MCP = MF->getConstantPool();
566  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
567  if (CP.empty()) return;
568
569  // Calculate sections for constant pool entries. We collect entries to go into
570  // the same section together to reduce amount of section switch statements.
571  SmallVector<SectionCPs, 4> CPSections;
572  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
573    const MachineConstantPoolEntry &CPE = CP[i];
574    unsigned Align = CPE.getAlignment();
575
576    SectionKind Kind;
577    switch (CPE.getRelocationInfo()) {
578    default: llvm_unreachable("Unknown section kind");
579    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
580    case 1:
581      Kind = SectionKind::getReadOnlyWithRelLocal();
582      break;
583    case 0:
584    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
585    case 4:  Kind = SectionKind::getMergeableConst4(); break;
586    case 8:  Kind = SectionKind::getMergeableConst8(); break;
587    case 16: Kind = SectionKind::getMergeableConst16();break;
588    default: Kind = SectionKind::getMergeableConst(); break;
589    }
590    }
591
592    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
593
594    // The number of sections are small, just do a linear search from the
595    // last section to the first.
596    bool Found = false;
597    unsigned SecIdx = CPSections.size();
598    while (SecIdx != 0) {
599      if (CPSections[--SecIdx].S == S) {
600        Found = true;
601        break;
602      }
603    }
604    if (!Found) {
605      SecIdx = CPSections.size();
606      CPSections.push_back(SectionCPs(S, Align));
607    }
608
609    if (Align > CPSections[SecIdx].Alignment)
610      CPSections[SecIdx].Alignment = Align;
611    CPSections[SecIdx].CPEs.push_back(i);
612  }
613
614  // Now print stuff into the calculated sections.
615  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
616    OutStreamer.SwitchSection(CPSections[i].S);
617    EmitAlignment(Log2_32(CPSections[i].Alignment));
618
619    unsigned Offset = 0;
620    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
621      unsigned CPI = CPSections[i].CPEs[j];
622      MachineConstantPoolEntry CPE = CP[CPI];
623
624      // Emit inter-object padding for alignment.
625      unsigned AlignMask = CPE.getAlignment() - 1;
626      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
627      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
628
629      const Type *Ty = CPE.getType();
630      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
631
632      // Emit the label with a comment on it.
633      if (VerboseAsm) {
634        OutStreamer.GetCommentOS() << "constant pool ";
635        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
636                          MF->getFunction()->getParent());
637        OutStreamer.GetCommentOS() << '\n';
638      }
639      OutStreamer.EmitLabel(GetCPISymbol(CPI));
640
641      if (CPE.isMachineConstantPoolEntry())
642        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
643      else
644        EmitGlobalConstant(CPE.Val.ConstVal);
645    }
646  }
647}
648
649/// EmitJumpTableInfo - Print assembly representations of the jump tables used
650/// by the current function to the current output stream.
651///
652void AsmPrinter::EmitJumpTableInfo() {
653  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
654  if (MJTI == 0) return;
655  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
656  if (JT.empty()) return;
657
658  // Pick the directive to use to print the jump table entries, and switch to
659  // the appropriate section.
660  const Function *F = MF->getFunction();
661  bool JTInDiffSection = false;
662  if (// In PIC mode, we need to emit the jump table to the same section as the
663      // function body itself, otherwise the label differences won't make sense.
664      // FIXME: Need a better predicate for this: what about custom entries?
665      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
666      // We should also do if the section name is NULL or function is declared
667      // in discardable section
668      // FIXME: this isn't the right predicate, should be based on the MCSection
669      // for the function.
670      F->isWeakForLinker()) {
671    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
672  } else {
673    // Otherwise, drop it in the readonly section.
674    const MCSection *ReadOnlySection =
675      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
676    OutStreamer.SwitchSection(ReadOnlySection);
677    JTInDiffSection = true;
678  }
679
680  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
681
682  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
683    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
684
685    // If this jump table was deleted, ignore it.
686    if (JTBBs.empty()) continue;
687
688    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
689    // .set directive for each unique entry.  This reduces the number of
690    // relocations the assembler will generate for the jump table.
691    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
692        MAI->hasSetDirective()) {
693      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
694      const TargetLowering *TLI = TM.getTargetLowering();
695      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
696      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
697        const MachineBasicBlock *MBB = JTBBs[ii];
698        if (!EmittedSets.insert(MBB)) continue;
699
700        // .set LJTSet, LBB32-base
701        const MCExpr *LHS =
702          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
703        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
704                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
705      }
706    }
707
708    // On some targets (e.g. Darwin) we want to emit two consequtive labels
709    // before each jump table.  The first label is never referenced, but tells
710    // the assembler and linker the extents of the jump table object.  The
711    // second label is actually referenced by the code.
712    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
713      // FIXME: This doesn't have to have any specific name, just any randomly
714      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
715      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
716
717    OutStreamer.EmitLabel(GetJTISymbol(JTI));
718
719    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
720      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
721  }
722}
723
724/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
725/// current stream.
726void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
727                                    const MachineBasicBlock *MBB,
728                                    unsigned UID) const {
729  const MCExpr *Value = 0;
730  switch (MJTI->getEntryKind()) {
731  case MachineJumpTableInfo::EK_Custom32:
732    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
733                                                              OutContext);
734    break;
735  case MachineJumpTableInfo::EK_BlockAddress:
736    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
737    //     .word LBB123
738    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
739    break;
740  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
741    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
742    // with a relocation as gp-relative, e.g.:
743    //     .gprel32 LBB123
744    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
745    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
746    return;
747  }
748
749  case MachineJumpTableInfo::EK_LabelDifference32: {
750    // EK_LabelDifference32 - Each entry is the address of the block minus
751    // the address of the jump table.  This is used for PIC jump tables where
752    // gprel32 is not supported.  e.g.:
753    //      .word LBB123 - LJTI1_2
754    // If the .set directive is supported, this is emitted as:
755    //      .set L4_5_set_123, LBB123 - LJTI1_2
756    //      .word L4_5_set_123
757
758    // If we have emitted set directives for the jump table entries, print
759    // them rather than the entries themselves.  If we're emitting PIC, then
760    // emit the table entries as differences between two text section labels.
761    if (MAI->hasSetDirective()) {
762      // If we used .set, reference the .set's symbol.
763      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
764                                      OutContext);
765      break;
766    }
767    // Otherwise, use the difference as the jump table entry.
768    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
769    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
770    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
771    break;
772  }
773  }
774
775  assert(Value && "Unknown entry kind!");
776
777  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
778  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
779}
780
781
782/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
783/// special global used by LLVM.  If so, emit it and return true, otherwise
784/// do nothing and return false.
785bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
786  if (GV->getName() == "llvm.used") {
787    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
788      EmitLLVMUsedList(GV->getInitializer());
789    return true;
790  }
791
792  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
793  if (GV->getSection() == "llvm.metadata" ||
794      GV->hasAvailableExternallyLinkage())
795    return true;
796
797  if (!GV->hasAppendingLinkage()) return false;
798
799  assert(GV->hasInitializer() && "Not a special LLVM global!");
800
801  const TargetData *TD = TM.getTargetData();
802  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
803  if (GV->getName() == "llvm.global_ctors") {
804    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
805    EmitAlignment(Align, 0);
806    EmitXXStructorList(GV->getInitializer());
807
808    if (TM.getRelocationModel() == Reloc::Static &&
809        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
810      StringRef Sym(".constructors_used");
811      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
812                                      MCSA_Reference);
813    }
814    return true;
815  }
816
817  if (GV->getName() == "llvm.global_dtors") {
818    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
819    EmitAlignment(Align, 0);
820    EmitXXStructorList(GV->getInitializer());
821
822    if (TM.getRelocationModel() == Reloc::Static &&
823        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
824      StringRef Sym(".destructors_used");
825      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
826                                      MCSA_Reference);
827    }
828    return true;
829  }
830
831  return false;
832}
833
834/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
835/// global in the specified llvm.used list for which emitUsedDirectiveFor
836/// is true, as being used with this directive.
837void AsmPrinter::EmitLLVMUsedList(Constant *List) {
838  // Should be an array of 'i8*'.
839  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
840  if (InitList == 0) return;
841
842  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
843    const GlobalValue *GV =
844      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
845    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
846      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
847                                      MCSA_NoDeadStrip);
848  }
849}
850
851/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
852/// function pointers, ignoring the init priority.
853void AsmPrinter::EmitXXStructorList(Constant *List) {
854  // Should be an array of '{ int, void ()* }' structs.  The first value is the
855  // init priority, which we ignore.
856  if (!isa<ConstantArray>(List)) return;
857  ConstantArray *InitList = cast<ConstantArray>(List);
858  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
859    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
860      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
861
862      if (CS->getOperand(1)->isNullValue())
863        return;  // Found a null terminator, exit printing.
864      // Emit the function pointer.
865      EmitGlobalConstant(CS->getOperand(1));
866    }
867}
868
869//===--------------------------------------------------------------------===//
870// Emission and print routines
871//
872
873/// EmitInt8 - Emit a byte directive and value.
874///
875void AsmPrinter::EmitInt8(int Value) const {
876  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
877}
878
879/// EmitInt16 - Emit a short directive and value.
880///
881void AsmPrinter::EmitInt16(int Value) const {
882  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
883}
884
885/// EmitInt32 - Emit a long directive and value.
886///
887void AsmPrinter::EmitInt32(int Value) const {
888  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
889}
890
891/// EmitInt64 - Emit a long long directive and value.
892///
893void AsmPrinter::EmitInt64(uint64_t Value) const {
894  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
895}
896
897//===----------------------------------------------------------------------===//
898
899// EmitAlignment - Emit an alignment directive to the specified power of
900// two boundary.  For example, if you pass in 3 here, you will get an 8
901// byte alignment.  If a global value is specified, and if that global has
902// an explicit alignment requested, it will unconditionally override the
903// alignment request.  However, if ForcedAlignBits is specified, this value
904// has final say: the ultimate alignment will be the max of ForcedAlignBits
905// and the alignment computed with NumBits and the global.
906//
907// The algorithm is:
908//     Align = NumBits;
909//     if (GV && GV->hasalignment) Align = GV->getalignment();
910//     Align = std::max(Align, ForcedAlignBits);
911//
912void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
913                               unsigned ForcedAlignBits,
914                               bool UseFillExpr) const {
915  if (GV && GV->getAlignment())
916    NumBits = Log2_32(GV->getAlignment());
917  NumBits = std::max(NumBits, ForcedAlignBits);
918
919  if (NumBits == 0) return;   // No need to emit alignment.
920
921  if (getCurrentSection()->getKind().isText())
922    OutStreamer.EmitCodeAlignment(1 << NumBits);
923  else
924    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
925}
926
927/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
928///
929static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
930  MCContext &Ctx = AP.OutContext;
931
932  if (CV->isNullValue() || isa<UndefValue>(CV))
933    return MCConstantExpr::Create(0, Ctx);
934
935  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
936    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
937
938  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
939    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
940  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
941    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
942
943  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
944  if (CE == 0) {
945    llvm_unreachable("Unknown constant value to lower!");
946    return MCConstantExpr::Create(0, Ctx);
947  }
948
949  switch (CE->getOpcode()) {
950  default:
951    // If the code isn't optimized, there may be outstanding folding
952    // opportunities. Attempt to fold the expression using TargetData as a
953    // last resort before giving up.
954    if (Constant *C =
955          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
956      if (C != CE)
957        return LowerConstant(C, AP);
958#ifndef NDEBUG
959    CE->dump();
960#endif
961    llvm_unreachable("FIXME: Don't support this constant expr");
962  case Instruction::GetElementPtr: {
963    const TargetData &TD = *AP.TM.getTargetData();
964    // Generate a symbolic expression for the byte address
965    const Constant *PtrVal = CE->getOperand(0);
966    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
967    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
968                                         IdxVec.size());
969
970    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
971    if (Offset == 0)
972      return Base;
973
974    // Truncate/sext the offset to the pointer size.
975    if (TD.getPointerSizeInBits() != 64) {
976      int SExtAmount = 64-TD.getPointerSizeInBits();
977      Offset = (Offset << SExtAmount) >> SExtAmount;
978    }
979
980    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
981                                   Ctx);
982  }
983
984  case Instruction::Trunc:
985    // We emit the value and depend on the assembler to truncate the generated
986    // expression properly.  This is important for differences between
987    // blockaddress labels.  Since the two labels are in the same function, it
988    // is reasonable to treat their delta as a 32-bit value.
989    // FALL THROUGH.
990  case Instruction::BitCast:
991    return LowerConstant(CE->getOperand(0), AP);
992
993  case Instruction::IntToPtr: {
994    const TargetData &TD = *AP.TM.getTargetData();
995    // Handle casts to pointers by changing them into casts to the appropriate
996    // integer type.  This promotes constant folding and simplifies this code.
997    Constant *Op = CE->getOperand(0);
998    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
999                                      false/*ZExt*/);
1000    return LowerConstant(Op, AP);
1001  }
1002
1003  case Instruction::PtrToInt: {
1004    const TargetData &TD = *AP.TM.getTargetData();
1005    // Support only foldable casts to/from pointers that can be eliminated by
1006    // changing the pointer to the appropriately sized integer type.
1007    Constant *Op = CE->getOperand(0);
1008    const Type *Ty = CE->getType();
1009
1010    const MCExpr *OpExpr = LowerConstant(Op, AP);
1011
1012    // We can emit the pointer value into this slot if the slot is an
1013    // integer slot equal to the size of the pointer.
1014    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1015      return OpExpr;
1016
1017    // Otherwise the pointer is smaller than the resultant integer, mask off
1018    // the high bits so we are sure to get a proper truncation if the input is
1019    // a constant expr.
1020    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1021    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1022    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1023  }
1024
1025  // The MC library also has a right-shift operator, but it isn't consistently
1026  // signed or unsigned between different targets.
1027  case Instruction::Add:
1028  case Instruction::Sub:
1029  case Instruction::Mul:
1030  case Instruction::SDiv:
1031  case Instruction::SRem:
1032  case Instruction::Shl:
1033  case Instruction::And:
1034  case Instruction::Or:
1035  case Instruction::Xor: {
1036    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1037    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1038    switch (CE->getOpcode()) {
1039    default: llvm_unreachable("Unknown binary operator constant cast expr");
1040    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1041    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1042    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1043    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1044    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1045    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1046    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1047    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1048    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1049    }
1050  }
1051  }
1052}
1053
1054static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1055                                    AsmPrinter &AP) {
1056  if (AddrSpace != 0 || !CA->isString()) {
1057    // Not a string.  Print the values in successive locations
1058    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1059      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1060    return;
1061  }
1062
1063  // Otherwise, it can be emitted as .ascii.
1064  SmallVector<char, 128> TmpVec;
1065  TmpVec.reserve(CA->getNumOperands());
1066  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1067    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1068
1069  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1070}
1071
1072static void EmitGlobalConstantVector(const ConstantVector *CV,
1073                                     unsigned AddrSpace, AsmPrinter &AP) {
1074  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1075    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1076}
1077
1078static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1079                                     unsigned AddrSpace, AsmPrinter &AP) {
1080  // Print the fields in successive locations. Pad to align if needed!
1081  const TargetData *TD = AP.TM.getTargetData();
1082  unsigned Size = TD->getTypeAllocSize(CS->getType());
1083  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1084  uint64_t SizeSoFar = 0;
1085  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1086    const Constant *Field = CS->getOperand(i);
1087
1088    // Check if padding is needed and insert one or more 0s.
1089    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1090    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1091                        - Layout->getElementOffset(i)) - FieldSize;
1092    SizeSoFar += FieldSize + PadSize;
1093
1094    // Now print the actual field value.
1095    AP.EmitGlobalConstant(Field, AddrSpace);
1096
1097    // Insert padding - this may include padding to increase the size of the
1098    // current field up to the ABI size (if the struct is not packed) as well
1099    // as padding to ensure that the next field starts at the right offset.
1100    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1101  }
1102  assert(SizeSoFar == Layout->getSizeInBytes() &&
1103         "Layout of constant struct may be incorrect!");
1104}
1105
1106static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1107                                 AsmPrinter &AP) {
1108  // FP Constants are printed as integer constants to avoid losing
1109  // precision.
1110  if (CFP->getType()->isDoubleTy()) {
1111    if (AP.VerboseAsm) {
1112      double Val = CFP->getValueAPF().convertToDouble();
1113      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1114    }
1115
1116    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1117    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1118    return;
1119  }
1120
1121  if (CFP->getType()->isFloatTy()) {
1122    if (AP.VerboseAsm) {
1123      float Val = CFP->getValueAPF().convertToFloat();
1124      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1125    }
1126    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1127    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1128    return;
1129  }
1130
1131  if (CFP->getType()->isX86_FP80Ty()) {
1132    // all long double variants are printed as hex
1133    // api needed to prevent premature destruction
1134    APInt API = CFP->getValueAPF().bitcastToAPInt();
1135    const uint64_t *p = API.getRawData();
1136    if (AP.VerboseAsm) {
1137      // Convert to double so we can print the approximate val as a comment.
1138      APFloat DoubleVal = CFP->getValueAPF();
1139      bool ignored;
1140      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1141                        &ignored);
1142      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1143        << DoubleVal.convertToDouble() << '\n';
1144    }
1145
1146    if (AP.TM.getTargetData()->isBigEndian()) {
1147      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1148      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1149    } else {
1150      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1151      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1152    }
1153
1154    // Emit the tail padding for the long double.
1155    const TargetData &TD = *AP.TM.getTargetData();
1156    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1157                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1158    return;
1159  }
1160
1161  assert(CFP->getType()->isPPC_FP128Ty() &&
1162         "Floating point constant type not handled");
1163  // All long double variants are printed as hex api needed to prevent
1164  // premature destruction.
1165  APInt API = CFP->getValueAPF().bitcastToAPInt();
1166  const uint64_t *p = API.getRawData();
1167  if (AP.TM.getTargetData()->isBigEndian()) {
1168    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1169    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1170  } else {
1171    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1172    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1173  }
1174}
1175
1176static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1177                                       unsigned AddrSpace, AsmPrinter &AP) {
1178  const TargetData *TD = AP.TM.getTargetData();
1179  unsigned BitWidth = CI->getBitWidth();
1180  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1181
1182  // We don't expect assemblers to support integer data directives
1183  // for more than 64 bits, so we emit the data in at most 64-bit
1184  // quantities at a time.
1185  const uint64_t *RawData = CI->getValue().getRawData();
1186  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1187    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1188    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1189  }
1190}
1191
1192/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1193void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1194  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1195    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1196    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1197    return OutStreamer.EmitZeros(Size, AddrSpace);
1198  }
1199
1200  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1201    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1202    switch (Size) {
1203    case 1:
1204    case 2:
1205    case 4:
1206    case 8:
1207      if (VerboseAsm)
1208        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1209      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1210      return;
1211    default:
1212      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1213      return;
1214    }
1215  }
1216
1217  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1218    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1219
1220  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1221    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1222
1223  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1224    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1225
1226  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1227    return EmitGlobalConstantVector(V, AddrSpace, *this);
1228
1229  if (isa<ConstantPointerNull>(CV)) {
1230    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1231    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1232    return;
1233  }
1234
1235  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1236  // thread the streamer with EmitValue.
1237  OutStreamer.EmitValue(LowerConstant(CV, *this),
1238                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1239                        AddrSpace);
1240}
1241
1242void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1243  // Target doesn't support this yet!
1244  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1245}
1246
1247/// PrintSpecial - Print information related to the specified machine instr
1248/// that is independent of the operand, and may be independent of the instr
1249/// itself.  This can be useful for portably encoding the comment character
1250/// or other bits of target-specific knowledge into the asmstrings.  The
1251/// syntax used is ${:comment}.  Targets can override this to add support
1252/// for their own strange codes.
1253void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1254  if (!strcmp(Code, "private")) {
1255    O << MAI->getPrivateGlobalPrefix();
1256  } else if (!strcmp(Code, "comment")) {
1257    if (VerboseAsm)
1258      O << MAI->getCommentString();
1259  } else if (!strcmp(Code, "uid")) {
1260    // Comparing the address of MI isn't sufficient, because machineinstrs may
1261    // be allocated to the same address across functions.
1262    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1263
1264    // If this is a new LastFn instruction, bump the counter.
1265    if (LastMI != MI || LastFn != ThisF) {
1266      ++Counter;
1267      LastMI = MI;
1268      LastFn = ThisF;
1269    }
1270    O << Counter;
1271  } else {
1272    std::string msg;
1273    raw_string_ostream Msg(msg);
1274    Msg << "Unknown special formatter '" << Code
1275         << "' for machine instr: " << *MI;
1276    llvm_report_error(Msg.str());
1277  }
1278}
1279
1280/// processDebugLoc - Processes the debug information of each machine
1281/// instruction's DebugLoc.
1282void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1283                                 bool BeforePrintingInsn) {
1284  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1285      || !DW->ShouldEmitDwarfDebug())
1286    return;
1287  DebugLoc DL = MI->getDebugLoc();
1288  if (DL.isUnknown())
1289    return;
1290  DILocation CurDLT = MF->getDILocation(DL);
1291  if (CurDLT.getScope().isNull())
1292    return;
1293
1294  if (!BeforePrintingInsn) {
1295    // After printing instruction
1296    DW->EndScope(MI);
1297  } else if (CurDLT.getNode() != PrevDLT) {
1298    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1299                                      CurDLT.getColumnNumber(),
1300                                      CurDLT.getScope().getNode());
1301    printLabel(L);
1302    O << '\n';
1303    DW->BeginScope(MI, L);
1304    PrevDLT = CurDLT.getNode();
1305  }
1306}
1307
1308
1309/// printInlineAsm - This method formats and prints the specified machine
1310/// instruction that is an inline asm.
1311void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1312  unsigned NumOperands = MI->getNumOperands();
1313
1314  // Count the number of register definitions.
1315  unsigned NumDefs = 0;
1316  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1317       ++NumDefs)
1318    assert(NumDefs != NumOperands-1 && "No asm string?");
1319
1320  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1321
1322  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1323  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1324
1325  O << '\t';
1326
1327  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1328  // These are useful to see where empty asm's wound up.
1329  if (AsmStr[0] == 0) {
1330    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1331    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1332    return;
1333  }
1334
1335  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1336
1337  // The variant of the current asmprinter.
1338  int AsmPrinterVariant = MAI->getAssemblerDialect();
1339
1340  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1341  const char *LastEmitted = AsmStr; // One past the last character emitted.
1342
1343  while (*LastEmitted) {
1344    switch (*LastEmitted) {
1345    default: {
1346      // Not a special case, emit the string section literally.
1347      const char *LiteralEnd = LastEmitted+1;
1348      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1349             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1350        ++LiteralEnd;
1351      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1352        O.write(LastEmitted, LiteralEnd-LastEmitted);
1353      LastEmitted = LiteralEnd;
1354      break;
1355    }
1356    case '\n':
1357      ++LastEmitted;   // Consume newline character.
1358      O << '\n';       // Indent code with newline.
1359      break;
1360    case '$': {
1361      ++LastEmitted;   // Consume '$' character.
1362      bool Done = true;
1363
1364      // Handle escapes.
1365      switch (*LastEmitted) {
1366      default: Done = false; break;
1367      case '$':     // $$ -> $
1368        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1369          O << '$';
1370        ++LastEmitted;  // Consume second '$' character.
1371        break;
1372      case '(':             // $( -> same as GCC's { character.
1373        ++LastEmitted;      // Consume '(' character.
1374        if (CurVariant != -1) {
1375          llvm_report_error("Nested variants found in inline asm string: '"
1376                            + std::string(AsmStr) + "'");
1377        }
1378        CurVariant = 0;     // We're in the first variant now.
1379        break;
1380      case '|':
1381        ++LastEmitted;  // consume '|' character.
1382        if (CurVariant == -1)
1383          O << '|';       // this is gcc's behavior for | outside a variant
1384        else
1385          ++CurVariant;   // We're in the next variant.
1386        break;
1387      case ')':         // $) -> same as GCC's } char.
1388        ++LastEmitted;  // consume ')' character.
1389        if (CurVariant == -1)
1390          O << '}';     // this is gcc's behavior for } outside a variant
1391        else
1392          CurVariant = -1;
1393        break;
1394      }
1395      if (Done) break;
1396
1397      bool HasCurlyBraces = false;
1398      if (*LastEmitted == '{') {     // ${variable}
1399        ++LastEmitted;               // Consume '{' character.
1400        HasCurlyBraces = true;
1401      }
1402
1403      // If we have ${:foo}, then this is not a real operand reference, it is a
1404      // "magic" string reference, just like in .td files.  Arrange to call
1405      // PrintSpecial.
1406      if (HasCurlyBraces && *LastEmitted == ':') {
1407        ++LastEmitted;
1408        const char *StrStart = LastEmitted;
1409        const char *StrEnd = strchr(StrStart, '}');
1410        if (StrEnd == 0) {
1411          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1412                            + std::string(AsmStr) + "'");
1413        }
1414
1415        std::string Val(StrStart, StrEnd);
1416        PrintSpecial(MI, Val.c_str());
1417        LastEmitted = StrEnd+1;
1418        break;
1419      }
1420
1421      const char *IDStart = LastEmitted;
1422      char *IDEnd;
1423      errno = 0;
1424      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1425      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1426        llvm_report_error("Bad $ operand number in inline asm string: '"
1427                          + std::string(AsmStr) + "'");
1428      }
1429      LastEmitted = IDEnd;
1430
1431      char Modifier[2] = { 0, 0 };
1432
1433      if (HasCurlyBraces) {
1434        // If we have curly braces, check for a modifier character.  This
1435        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1436        if (*LastEmitted == ':') {
1437          ++LastEmitted;    // Consume ':' character.
1438          if (*LastEmitted == 0) {
1439            llvm_report_error("Bad ${:} expression in inline asm string: '"
1440                              + std::string(AsmStr) + "'");
1441          }
1442
1443          Modifier[0] = *LastEmitted;
1444          ++LastEmitted;    // Consume modifier character.
1445        }
1446
1447        if (*LastEmitted != '}') {
1448          llvm_report_error("Bad ${} expression in inline asm string: '"
1449                            + std::string(AsmStr) + "'");
1450        }
1451        ++LastEmitted;    // Consume '}' character.
1452      }
1453
1454      if ((unsigned)Val >= NumOperands-1) {
1455        llvm_report_error("Invalid $ operand number in inline asm string: '"
1456                          + std::string(AsmStr) + "'");
1457      }
1458
1459      // Okay, we finally have a value number.  Ask the target to print this
1460      // operand!
1461      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1462        unsigned OpNo = 1;
1463
1464        bool Error = false;
1465
1466        // Scan to find the machine operand number for the operand.
1467        for (; Val; --Val) {
1468          if (OpNo >= MI->getNumOperands()) break;
1469          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1470          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1471        }
1472
1473        if (OpNo >= MI->getNumOperands()) {
1474          Error = true;
1475        } else {
1476          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1477          ++OpNo;  // Skip over the ID number.
1478
1479          if (Modifier[0] == 'l')  // labels are target independent
1480            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1481          else {
1482            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1483            if ((OpFlags & 7) == 4) {
1484              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1485                                                Modifier[0] ? Modifier : 0);
1486            } else {
1487              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1488                                          Modifier[0] ? Modifier : 0);
1489            }
1490          }
1491        }
1492        if (Error) {
1493          std::string msg;
1494          raw_string_ostream Msg(msg);
1495          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1496          MI->print(Msg);
1497          llvm_report_error(Msg.str());
1498        }
1499      }
1500      break;
1501    }
1502    }
1503  }
1504  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1505  OutStreamer.AddBlankLine();
1506}
1507
1508/// printImplicitDef - This method prints the specified machine instruction
1509/// that is an implicit def.
1510void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1511  if (!VerboseAsm) return;
1512  O.PadToColumn(MAI->getCommentColumn());
1513  O << MAI->getCommentString() << " implicit-def: "
1514    << TRI->getName(MI->getOperand(0).getReg());
1515  OutStreamer.AddBlankLine();
1516}
1517
1518void AsmPrinter::printKill(const MachineInstr *MI) const {
1519  if (!VerboseAsm) return;
1520  O.PadToColumn(MAI->getCommentColumn());
1521  O << MAI->getCommentString() << " kill:";
1522  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1523    const MachineOperand &op = MI->getOperand(n);
1524    assert(op.isReg() && "KILL instruction must have only register operands");
1525    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1526  }
1527  OutStreamer.AddBlankLine();
1528}
1529
1530/// printLabel - This method prints a local label used by debug and
1531/// exception handling tables.
1532void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1533  printLabel(MI->getOperand(0).getImm());
1534  OutStreamer.AddBlankLine();
1535}
1536
1537void AsmPrinter::printLabel(unsigned Id) const {
1538  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1539}
1540
1541/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1542/// instruction, using the specified assembler variant.  Targets should
1543/// override this to format as appropriate.
1544bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1545                                 unsigned AsmVariant, const char *ExtraCode) {
1546  // Target doesn't support this yet!
1547  return true;
1548}
1549
1550bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1551                                       unsigned AsmVariant,
1552                                       const char *ExtraCode) {
1553  // Target doesn't support this yet!
1554  return true;
1555}
1556
1557MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1558  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock());
1559}
1560
1561MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1562                                            const BasicBlock *BB) const {
1563  assert(BB->hasName() &&
1564         "Address of anonymous basic block not supported yet!");
1565
1566  // This code must use the function name itself, and not the function number,
1567  // since it must be possible to generate the label name from within other
1568  // functions.
1569  SmallString<60> FnName;
1570  Mang->getNameWithPrefix(FnName, F, false);
1571
1572  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1573  SmallString<60> NameResult;
1574  Mang->getNameWithPrefix(NameResult,
1575                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1576                          "_" + FnName.str() + "_" + BB->getName(),
1577                          Mangler::Private);
1578
1579  return OutContext.GetOrCreateSymbol(NameResult.str());
1580}
1581
1582/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1583MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1584  SmallString<60> Name;
1585  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1586    << getFunctionNumber() << '_' << CPID;
1587  return OutContext.GetOrCreateSymbol(Name.str());
1588}
1589
1590/// GetJTISymbol - Return the symbol for the specified jump table entry.
1591MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1592  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1593}
1594
1595/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1596/// FIXME: privatize to AsmPrinter.
1597MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1598  SmallString<60> Name;
1599  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1600    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1601  return OutContext.GetOrCreateSymbol(Name.str());
1602}
1603
1604/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1605/// value.
1606MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1607  SmallString<60> NameStr;
1608  Mang->getNameWithPrefix(NameStr, GV, false);
1609  return OutContext.GetOrCreateSymbol(NameStr.str());
1610}
1611
1612/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1613/// global value name as its base, with the specified suffix, and where the
1614/// symbol is forced to have private linkage if ForcePrivate is true.
1615MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1616                                                   StringRef Suffix,
1617                                                   bool ForcePrivate) const {
1618  SmallString<60> NameStr;
1619  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1620  NameStr.append(Suffix.begin(), Suffix.end());
1621  return OutContext.GetOrCreateSymbol(NameStr.str());
1622}
1623
1624/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1625/// ExternalSymbol.
1626MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1627  SmallString<60> NameStr;
1628  Mang->getNameWithPrefix(NameStr, Sym);
1629  return OutContext.GetOrCreateSymbol(NameStr.str());
1630}
1631
1632
1633
1634/// PrintParentLoopComment - Print comments about parent loops of this one.
1635static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1636                                   unsigned FunctionNumber) {
1637  if (Loop == 0) return;
1638  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1639  OS.indent(Loop->getLoopDepth()*2)
1640    << "Parent Loop BB" << FunctionNumber << "_"
1641    << Loop->getHeader()->getNumber()
1642    << " Depth=" << Loop->getLoopDepth() << '\n';
1643}
1644
1645
1646/// PrintChildLoopComment - Print comments about child loops within
1647/// the loop for this basic block, with nesting.
1648static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1649                                  unsigned FunctionNumber) {
1650  // Add child loop information
1651  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1652    OS.indent((*CL)->getLoopDepth()*2)
1653      << "Child Loop BB" << FunctionNumber << "_"
1654      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1655      << '\n';
1656    PrintChildLoopComment(OS, *CL, FunctionNumber);
1657  }
1658}
1659
1660/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1661static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1662                                        const MachineLoopInfo *LI,
1663                                        const AsmPrinter &AP) {
1664  // Add loop depth information
1665  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1666  if (Loop == 0) return;
1667
1668  MachineBasicBlock *Header = Loop->getHeader();
1669  assert(Header && "No header for loop");
1670
1671  // If this block is not a loop header, just print out what is the loop header
1672  // and return.
1673  if (Header != &MBB) {
1674    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1675                              Twine(AP.getFunctionNumber())+"_" +
1676                              Twine(Loop->getHeader()->getNumber())+
1677                              " Depth="+Twine(Loop->getLoopDepth()));
1678    return;
1679  }
1680
1681  // Otherwise, it is a loop header.  Print out information about child and
1682  // parent loops.
1683  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1684
1685  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1686
1687  OS << "=>";
1688  OS.indent(Loop->getLoopDepth()*2-2);
1689
1690  OS << "This ";
1691  if (Loop->empty())
1692    OS << "Inner ";
1693  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1694
1695  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1696}
1697
1698
1699/// EmitBasicBlockStart - This method prints the label for the specified
1700/// MachineBasicBlock, an alignment (if present) and a comment describing
1701/// it if appropriate.
1702void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1703  // Emit an alignment directive for this block, if needed.
1704  if (unsigned Align = MBB->getAlignment())
1705    EmitAlignment(Log2_32(Align));
1706
1707  // If the block has its address taken, emit a special label to satisfy
1708  // references to the block. This is done so that we don't need to
1709  // remember the number of this label, and so that we can make
1710  // forward references to labels without knowing what their numbers
1711  // will be.
1712  if (MBB->hasAddressTaken()) {
1713    const BasicBlock *BB = MBB->getBasicBlock();
1714    if (VerboseAsm)
1715      OutStreamer.AddComment("Address Taken");
1716    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1717  }
1718
1719  // Print the main label for the block.
1720  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1721    if (VerboseAsm) {
1722      // NOTE: Want this comment at start of line.
1723      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1724      if (const BasicBlock *BB = MBB->getBasicBlock())
1725        if (BB->hasName())
1726          OutStreamer.AddComment("%" + BB->getName());
1727
1728      PrintBasicBlockLoopComments(*MBB, LI, *this);
1729      OutStreamer.AddBlankLine();
1730    }
1731  } else {
1732    if (VerboseAsm) {
1733      if (const BasicBlock *BB = MBB->getBasicBlock())
1734        if (BB->hasName())
1735          OutStreamer.AddComment("%" + BB->getName());
1736      PrintBasicBlockLoopComments(*MBB, LI, *this);
1737    }
1738
1739    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1740  }
1741}
1742
1743void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1744  MCSymbolAttr Attr = MCSA_Invalid;
1745
1746  switch (Visibility) {
1747  default: break;
1748  case GlobalValue::HiddenVisibility:
1749    Attr = MAI->getHiddenVisibilityAttr();
1750    break;
1751  case GlobalValue::ProtectedVisibility:
1752    Attr = MAI->getProtectedVisibilityAttr();
1753    break;
1754  }
1755
1756  if (Attr != MCSA_Invalid)
1757    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1758}
1759
1760void AsmPrinter::printOffset(int64_t Offset) const {
1761  if (Offset > 0)
1762    O << '+' << Offset;
1763  else if (Offset < 0)
1764    O << Offset;
1765}
1766
1767/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1768/// exactly one predecessor and the control transfer mechanism between
1769/// the predecessor and this block is a fall-through.
1770bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1771    const {
1772  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1773  // then nothing falls through to it.
1774  if (MBB->isLandingPad() || MBB->pred_empty())
1775    return false;
1776
1777  // If there isn't exactly one predecessor, it can't be a fall through.
1778  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1779  ++PI2;
1780  if (PI2 != MBB->pred_end())
1781    return false;
1782
1783  // The predecessor has to be immediately before this block.
1784  const MachineBasicBlock *Pred = *PI;
1785
1786  if (!Pred->isLayoutSuccessor(MBB))
1787    return false;
1788
1789  // If the block is completely empty, then it definitely does fall through.
1790  if (Pred->empty())
1791    return true;
1792
1793  // Otherwise, check the last instruction.
1794  const MachineInstr &LastInst = Pred->back();
1795  return !LastInst.getDesc().isBarrier();
1796}
1797
1798
1799
1800GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1801  if (!S->usesMetadata())
1802    return 0;
1803
1804  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1805  if (GCPI != GCMetadataPrinters.end())
1806    return GCPI->second;
1807
1808  const char *Name = S->getName().c_str();
1809
1810  for (GCMetadataPrinterRegistry::iterator
1811         I = GCMetadataPrinterRegistry::begin(),
1812         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1813    if (strcmp(Name, I->getName()) == 0) {
1814      GCMetadataPrinter *GMP = I->instantiate();
1815      GMP->S = S;
1816      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1817      return GMP;
1818    }
1819
1820  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1821  return 0;
1822}
1823
1824