AsmPrinter.cpp revision 744f579b63987854ac1b3f2f9c8d2659c5b5ee40 
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/DebugInfo.h"
29#include "llvm/MC/MCContext.h"
30#include "llvm/MC/MCExpr.h"
31#include "llvm/MC/MCInst.h"
32#include "llvm/MC/MCSection.h"
33#include "llvm/MC/MCStreamer.h"
34#include "llvm/MC/MCSymbol.h"
35#include "llvm/MC/MCAsmInfo.h"
36#include "llvm/Target/Mangler.h"
37#include "llvm/Target/TargetData.h"
38#include "llvm/Target/TargetInstrInfo.h"
39#include "llvm/Target/TargetLowering.h"
40#include "llvm/Target/TargetLoweringObjectFile.h"
41#include "llvm/Target/TargetOptions.h"
42#include "llvm/Target/TargetRegisterInfo.h"
43#include "llvm/ADT/SmallPtrSet.h"
44#include "llvm/ADT/SmallString.h"
45#include "llvm/ADT/Statistic.h"
46#include "llvm/Support/CommandLine.h"
47#include "llvm/Support/Debug.h"
48#include "llvm/Support/ErrorHandling.h"
49#include "llvm/Support/Format.h"
50#include "llvm/Support/FormattedStream.h"
51#include <cerrno>
52using namespace llvm;
53
54STATISTIC(EmittedInsts, "Number of machine instrs printed");
55
56char AsmPrinter::ID = 0;
57AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
58                       MCContext &Ctx, MCStreamer &Streamer,
59                       const MCAsmInfo *T)
60  : MachineFunctionPass(&ID), O(o),
61    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
62    OutContext(Ctx), OutStreamer(Streamer),
63    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
64  DW = 0; MMI = 0;
65  VerboseAsm = Streamer.isVerboseAsm();
66}
67
68AsmPrinter::~AsmPrinter() {
69  for (gcp_iterator I = GCMetadataPrinters.begin(),
70                    E = GCMetadataPrinters.end(); I != E; ++I)
71    delete I->second;
72
73  delete &OutStreamer;
74  delete &OutContext;
75}
76
77/// getFunctionNumber - Return a unique ID for the current function.
78///
79unsigned AsmPrinter::getFunctionNumber() const {
80  return MF->getFunctionNumber();
81}
82
83TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
84  return TM.getTargetLowering()->getObjFileLowering();
85}
86
87/// getCurrentSection() - Return the current section we are emitting to.
88const MCSection *AsmPrinter::getCurrentSection() const {
89  return OutStreamer.getCurrentSection();
90}
91
92
93void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
94  AU.setPreservesAll();
95  MachineFunctionPass::getAnalysisUsage(AU);
96  AU.addRequired<GCModuleInfo>();
97  if (VerboseAsm)
98    AU.addRequired<MachineLoopInfo>();
99}
100
101bool AsmPrinter::doInitialization(Module &M) {
102  // Initialize TargetLoweringObjectFile.
103  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
104    .Initialize(OutContext, TM);
105
106  Mang = new Mangler(*MAI);
107
108  // Allow the target to emit any magic that it wants at the start of the file.
109  EmitStartOfAsmFile(M);
110
111  // Very minimal debug info. It is ignored if we emit actual debug info. If we
112  // don't, this at least helps the user find where a global came from.
113  if (MAI->hasSingleParameterDotFile()) {
114    // .file "foo.c"
115    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
116  }
117
118  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
119  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
120  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
121    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
122      MP->beginAssembly(O, *this, *MAI);
123
124  if (!M.getModuleInlineAsm().empty())
125    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
126      << M.getModuleInlineAsm()
127      << '\n' << MAI->getCommentString()
128      << " End of file scope inline assembly\n";
129
130  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
131  if (MMI)
132    MMI->AnalyzeModule(M);
133  DW = getAnalysisIfAvailable<DwarfWriter>();
134  if (DW)
135    DW->BeginModule(&M, MMI, O, this, MAI);
136
137  return false;
138}
139
140void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
141  switch ((GlobalValue::LinkageTypes)Linkage) {
142  case GlobalValue::CommonLinkage:
143  case GlobalValue::LinkOnceAnyLinkage:
144  case GlobalValue::LinkOnceODRLinkage:
145  case GlobalValue::WeakAnyLinkage:
146  case GlobalValue::WeakODRLinkage:
147  case GlobalValue::LinkerPrivateLinkage:
148    if (MAI->getWeakDefDirective() != 0) {
149      // .globl _foo
150      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
151      // .weak_definition _foo
152      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
153    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
154      // .globl _foo
155      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
156      // FIXME: linkonce should be a section attribute, handled by COFF Section
157      // assignment.
158      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
159      // .linkonce discard
160      // FIXME: It would be nice to use .linkonce samesize for non-common
161      // globals.
162      O << LinkOnce;
163    } else {
164      // .weak _foo
165      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
166    }
167    break;
168  case GlobalValue::DLLExportLinkage:
169  case GlobalValue::AppendingLinkage:
170    // FIXME: appending linkage variables should go into a section of
171    // their name or something.  For now, just emit them as external.
172  case GlobalValue::ExternalLinkage:
173    // If external or appending, declare as a global symbol.
174    // .globl _foo
175    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
176    break;
177  case GlobalValue::PrivateLinkage:
178  case GlobalValue::InternalLinkage:
179    break;
180  default:
181    llvm_unreachable("Unknown linkage type!");
182  }
183}
184
185
186/// EmitGlobalVariable - Emit the specified global variable to the .s file.
187void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
188  if (!GV->hasInitializer())   // External globals require no code.
189    return;
190
191  // Check to see if this is a special global used by LLVM, if so, emit it.
192  if (EmitSpecialLLVMGlobal(GV))
193    return;
194
195  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
196  EmitVisibility(GVSym, GV->getVisibility());
197
198  if (MAI->hasDotTypeDotSizeDirective())
199    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
200
201  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
202
203  const TargetData *TD = TM.getTargetData();
204  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
205  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
206
207  // Handle common and BSS local symbols (.lcomm).
208  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
209    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
210
211    if (VerboseAsm) {
212      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
213                     /*PrintType=*/false, GV->getParent());
214      OutStreamer.GetCommentOS() << '\n';
215    }
216
217    // Handle common symbols.
218    if (GVKind.isCommon()) {
219      // .comm _foo, 42, 4
220      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
221      return;
222    }
223
224    // Handle local BSS symbols.
225    if (MAI->hasMachoZeroFillDirective()) {
226      const MCSection *TheSection =
227        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
228      // .zerofill __DATA, __bss, _foo, 400, 5
229      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
230      return;
231    }
232
233    if (MAI->hasLCOMMDirective()) {
234      // .lcomm _foo, 42
235      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
236      return;
237    }
238
239    // .local _foo
240    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
241    // .comm _foo, 42, 4
242    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
243    return;
244  }
245
246  const MCSection *TheSection =
247    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
248
249  // Handle the zerofill directive on darwin, which is a special form of BSS
250  // emission.
251  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
252    // .globl _foo
253    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
254    // .zerofill __DATA, __common, _foo, 400, 5
255    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
256    return;
257  }
258
259  OutStreamer.SwitchSection(TheSection);
260
261  EmitLinkage(GV->getLinkage(), GVSym);
262  EmitAlignment(AlignLog, GV);
263
264  if (VerboseAsm) {
265    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
266                   /*PrintType=*/false, GV->getParent());
267    OutStreamer.GetCommentOS() << '\n';
268  }
269  OutStreamer.EmitLabel(GVSym);
270
271  EmitGlobalConstant(GV->getInitializer());
272
273  if (MAI->hasDotTypeDotSizeDirective())
274    // .size foo, 42
275    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
276
277  OutStreamer.AddBlankLine();
278}
279
280/// EmitFunctionHeader - This method emits the header for the current
281/// function.
282void AsmPrinter::EmitFunctionHeader() {
283  // Print out constants referenced by the function
284  EmitConstantPool();
285
286  // Print the 'header' of function.
287  const Function *F = MF->getFunction();
288
289  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
290  EmitVisibility(CurrentFnSym, F->getVisibility());
291
292  EmitLinkage(F->getLinkage(), CurrentFnSym);
293  EmitAlignment(MF->getAlignment(), F);
294
295  if (MAI->hasDotTypeDotSizeDirective())
296    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
297
298  if (VerboseAsm) {
299    WriteAsOperand(OutStreamer.GetCommentOS(), F,
300                   /*PrintType=*/false, F->getParent());
301    OutStreamer.GetCommentOS() << '\n';
302  }
303
304  // Emit the CurrentFnSym.  This is is a virtual function to allow targets to
305  // do their wild and crazy things as required.
306  EmitFunctionEntryLabel();
307
308  // Add some workaround for linkonce linkage on Cygwin\MinGW.
309  if (MAI->getLinkOnceDirective() != 0 &&
310      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
311    // FIXME: What is this?
312    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
313
314  // Emit pre-function debug and/or EH information.
315  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
316    DW->BeginFunction(MF);
317}
318
319/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
320/// function.  This can be overridden by targets as required to do custom stuff.
321void AsmPrinter::EmitFunctionEntryLabel() {
322  OutStreamer.EmitLabel(CurrentFnSym);
323}
324
325
326/// EmitFunctionBody - This method emits the body and trailer for a
327/// function.
328void AsmPrinter::EmitFunctionBody() {
329  // Emit target-specific gunk before the function body.
330  EmitFunctionBodyStart();
331
332  // Print out code for the function.
333  bool HasAnyRealCode = false;
334  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
335       I != E; ++I) {
336    // Print a label for the basic block.
337    EmitBasicBlockStart(I);
338    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
339         II != IE; ++II) {
340      // Print the assembly for the instruction.
341      if (!II->isLabel())
342        HasAnyRealCode = true;
343
344      ++EmittedInsts;
345
346      // FIXME: Clean up processDebugLoc.
347      processDebugLoc(II, true);
348
349      switch (II->getOpcode()) {
350      case TargetInstrInfo::DBG_LABEL:
351      case TargetInstrInfo::EH_LABEL:
352      case TargetInstrInfo::GC_LABEL:
353        printLabelInst(II);
354        break;
355      case TargetInstrInfo::INLINEASM:
356        printInlineAsm(II);
357        break;
358      case TargetInstrInfo::IMPLICIT_DEF:
359        printImplicitDef(II);
360        break;
361      case TargetInstrInfo::KILL:
362        printKill(II);
363        break;
364      default:
365        EmitInstruction(II);
366        break;
367      }
368      if (VerboseAsm)
369        EmitComments(*II);
370
371      // FIXME: Clean up processDebugLoc.
372      processDebugLoc(II, false);
373    }
374  }
375
376  // If the function is empty and the object file uses .subsections_via_symbols,
377  // then we need to emit *something* to the function body to prevent the
378  // labels from collapsing together.  Just emit a 0 byte.
379  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
380    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
381
382  // Emit target-specific gunk after the function body.
383  EmitFunctionBodyEnd();
384
385  if (MAI->hasDotTypeDotSizeDirective())
386    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
387
388  // Emit post-function debug information.
389  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
390    DW->EndFunction(MF);
391
392  // Print out jump tables referenced by the function.
393  EmitJumpTableInfo();
394
395  OutStreamer.AddBlankLine();
396}
397
398
399bool AsmPrinter::doFinalization(Module &M) {
400  // Emit global variables.
401  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
402       I != E; ++I)
403    EmitGlobalVariable(I);
404
405  // Emit final debug information.
406  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
407    DW->EndModule();
408
409  // If the target wants to know about weak references, print them all.
410  if (MAI->getWeakRefDirective()) {
411    // FIXME: This is not lazy, it would be nice to only print weak references
412    // to stuff that is actually used.  Note that doing so would require targets
413    // to notice uses in operands (due to constant exprs etc).  This should
414    // happen with the MC stuff eventually.
415
416    // Print out module-level global variables here.
417    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
418         I != E; ++I) {
419      if (!I->hasExternalWeakLinkage()) continue;
420      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
421                                      MCSA_WeakReference);
422    }
423
424    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
425      if (!I->hasExternalWeakLinkage()) continue;
426      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
427                                      MCSA_WeakReference);
428    }
429  }
430
431  if (MAI->hasSetDirective()) {
432    OutStreamer.AddBlankLine();
433    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
434         I != E; ++I) {
435      MCSymbol *Name = GetGlobalValueSymbol(I);
436
437      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
438      MCSymbol *Target = GetGlobalValueSymbol(GV);
439
440      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
441        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
442      else if (I->hasWeakLinkage())
443        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
444      else
445        assert(I->hasLocalLinkage() && "Invalid alias linkage");
446
447      EmitVisibility(Name, I->getVisibility());
448
449      // Emit the directives as assignments aka .set:
450      OutStreamer.EmitAssignment(Name,
451                                 MCSymbolRefExpr::Create(Target, OutContext));
452    }
453  }
454
455  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
456  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
457  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
458    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
459      MP->finishAssembly(O, *this, *MAI);
460
461  // If we don't have any trampolines, then we don't require stack memory
462  // to be executable. Some targets have a directive to declare this.
463  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
464  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
465    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
466      OutStreamer.SwitchSection(S);
467
468  // Allow the target to emit any magic that it wants at the end of the file,
469  // after everything else has gone out.
470  EmitEndOfAsmFile(M);
471
472  delete Mang; Mang = 0;
473  DW = 0; MMI = 0;
474
475  OutStreamer.Finish();
476  return false;
477}
478
479void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
480  this->MF = &MF;
481  // Get the function symbol.
482  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
483
484  if (VerboseAsm)
485    LI = &getAnalysis<MachineLoopInfo>();
486}
487
488namespace {
489  // SectionCPs - Keep track the alignment, constpool entries per Section.
490  struct SectionCPs {
491    const MCSection *S;
492    unsigned Alignment;
493    SmallVector<unsigned, 4> CPEs;
494    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
495  };
496}
497
498/// EmitConstantPool - Print to the current output stream assembly
499/// representations of the constants in the constant pool MCP. This is
500/// used to print out constants which have been "spilled to memory" by
501/// the code generator.
502///
503void AsmPrinter::EmitConstantPool() {
504  const MachineConstantPool *MCP = MF->getConstantPool();
505  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
506  if (CP.empty()) return;
507
508  // Calculate sections for constant pool entries. We collect entries to go into
509  // the same section together to reduce amount of section switch statements.
510  SmallVector<SectionCPs, 4> CPSections;
511  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
512    const MachineConstantPoolEntry &CPE = CP[i];
513    unsigned Align = CPE.getAlignment();
514
515    SectionKind Kind;
516    switch (CPE.getRelocationInfo()) {
517    default: llvm_unreachable("Unknown section kind");
518    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
519    case 1:
520      Kind = SectionKind::getReadOnlyWithRelLocal();
521      break;
522    case 0:
523    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
524    case 4:  Kind = SectionKind::getMergeableConst4(); break;
525    case 8:  Kind = SectionKind::getMergeableConst8(); break;
526    case 16: Kind = SectionKind::getMergeableConst16();break;
527    default: Kind = SectionKind::getMergeableConst(); break;
528    }
529    }
530
531    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
532
533    // The number of sections are small, just do a linear search from the
534    // last section to the first.
535    bool Found = false;
536    unsigned SecIdx = CPSections.size();
537    while (SecIdx != 0) {
538      if (CPSections[--SecIdx].S == S) {
539        Found = true;
540        break;
541      }
542    }
543    if (!Found) {
544      SecIdx = CPSections.size();
545      CPSections.push_back(SectionCPs(S, Align));
546    }
547
548    if (Align > CPSections[SecIdx].Alignment)
549      CPSections[SecIdx].Alignment = Align;
550    CPSections[SecIdx].CPEs.push_back(i);
551  }
552
553  // Now print stuff into the calculated sections.
554  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
555    OutStreamer.SwitchSection(CPSections[i].S);
556    EmitAlignment(Log2_32(CPSections[i].Alignment));
557
558    unsigned Offset = 0;
559    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
560      unsigned CPI = CPSections[i].CPEs[j];
561      MachineConstantPoolEntry CPE = CP[CPI];
562
563      // Emit inter-object padding for alignment.
564      unsigned AlignMask = CPE.getAlignment() - 1;
565      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
566      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
567
568      const Type *Ty = CPE.getType();
569      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
570
571      // Emit the label with a comment on it.
572      if (VerboseAsm) {
573        OutStreamer.GetCommentOS() << "constant pool ";
574        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
575                          MF->getFunction()->getParent());
576        OutStreamer.GetCommentOS() << '\n';
577      }
578      OutStreamer.EmitLabel(GetCPISymbol(CPI));
579
580      if (CPE.isMachineConstantPoolEntry())
581        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
582      else
583        EmitGlobalConstant(CPE.Val.ConstVal);
584    }
585  }
586}
587
588/// EmitJumpTableInfo - Print assembly representations of the jump tables used
589/// by the current function to the current output stream.
590///
591void AsmPrinter::EmitJumpTableInfo() {
592  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
593  if (MJTI == 0) return;
594  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
595  if (JT.empty()) return;
596
597  // Pick the directive to use to print the jump table entries, and switch to
598  // the appropriate section.
599  const Function *F = MF->getFunction();
600  bool JTInDiffSection = false;
601  if (// In PIC mode, we need to emit the jump table to the same section as the
602      // function body itself, otherwise the label differences won't make sense.
603      // FIXME: Need a better predicate for this: what about custom entries?
604      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
605      // We should also do if the section name is NULL or function is declared
606      // in discardable section
607      // FIXME: this isn't the right predicate, should be based on the MCSection
608      // for the function.
609      F->isWeakForLinker()) {
610    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
611  } else {
612    // Otherwise, drop it in the readonly section.
613    const MCSection *ReadOnlySection =
614      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
615    OutStreamer.SwitchSection(ReadOnlySection);
616    JTInDiffSection = true;
617  }
618
619  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
620
621  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
622    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
623
624    // If this jump table was deleted, ignore it.
625    if (JTBBs.empty()) continue;
626
627    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
628    // .set directive for each unique entry.  This reduces the number of
629    // relocations the assembler will generate for the jump table.
630    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
631        MAI->hasSetDirective()) {
632      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
633      const TargetLowering *TLI = TM.getTargetLowering();
634      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
635      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
636        const MachineBasicBlock *MBB = JTBBs[ii];
637        if (!EmittedSets.insert(MBB)) continue;
638
639        // .set LJTSet, LBB32-base
640        const MCExpr *LHS =
641          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
642        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
643                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
644      }
645    }
646
647    // On some targets (e.g. Darwin) we want to emit two consequtive labels
648    // before each jump table.  The first label is never referenced, but tells
649    // the assembler and linker the extents of the jump table object.  The
650    // second label is actually referenced by the code.
651    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
652      // FIXME: This doesn't have to have any specific name, just any randomly
653      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
654      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
655
656    OutStreamer.EmitLabel(GetJTISymbol(JTI));
657
658    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
659      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
660  }
661}
662
663/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
664/// current stream.
665void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
666                                    const MachineBasicBlock *MBB,
667                                    unsigned UID) const {
668  const MCExpr *Value = 0;
669  switch (MJTI->getEntryKind()) {
670  case MachineJumpTableInfo::EK_Custom32:
671    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
672                                                              OutContext);
673    break;
674  case MachineJumpTableInfo::EK_BlockAddress:
675    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
676    //     .word LBB123
677    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
678    break;
679  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
680    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
681    // with a relocation as gp-relative, e.g.:
682    //     .gprel32 LBB123
683    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
684    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
685    return;
686  }
687
688  case MachineJumpTableInfo::EK_LabelDifference32: {
689    // EK_LabelDifference32 - Each entry is the address of the block minus
690    // the address of the jump table.  This is used for PIC jump tables where
691    // gprel32 is not supported.  e.g.:
692    //      .word LBB123 - LJTI1_2
693    // If the .set directive is supported, this is emitted as:
694    //      .set L4_5_set_123, LBB123 - LJTI1_2
695    //      .word L4_5_set_123
696
697    // If we have emitted set directives for the jump table entries, print
698    // them rather than the entries themselves.  If we're emitting PIC, then
699    // emit the table entries as differences between two text section labels.
700    if (MAI->hasSetDirective()) {
701      // If we used .set, reference the .set's symbol.
702      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
703                                      OutContext);
704      break;
705    }
706    // Otherwise, use the difference as the jump table entry.
707    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
708    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
709    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
710    break;
711  }
712  }
713
714  assert(Value && "Unknown entry kind!");
715
716  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
717  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
718}
719
720
721/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
722/// special global used by LLVM.  If so, emit it and return true, otherwise
723/// do nothing and return false.
724bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
725  if (GV->getName() == "llvm.used") {
726    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
727      EmitLLVMUsedList(GV->getInitializer());
728    return true;
729  }
730
731  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
732  if (GV->getSection() == "llvm.metadata" ||
733      GV->hasAvailableExternallyLinkage())
734    return true;
735
736  if (!GV->hasAppendingLinkage()) return false;
737
738  assert(GV->hasInitializer() && "Not a special LLVM global!");
739
740  const TargetData *TD = TM.getTargetData();
741  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
742  if (GV->getName() == "llvm.global_ctors") {
743    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
744    EmitAlignment(Align, 0);
745    EmitXXStructorList(GV->getInitializer());
746
747    if (TM.getRelocationModel() == Reloc::Static &&
748        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
749      StringRef Sym(".constructors_used");
750      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
751                                      MCSA_Reference);
752    }
753    return true;
754  }
755
756  if (GV->getName() == "llvm.global_dtors") {
757    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
758    EmitAlignment(Align, 0);
759    EmitXXStructorList(GV->getInitializer());
760
761    if (TM.getRelocationModel() == Reloc::Static &&
762        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
763      StringRef Sym(".destructors_used");
764      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
765                                      MCSA_Reference);
766    }
767    return true;
768  }
769
770  return false;
771}
772
773/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
774/// global in the specified llvm.used list for which emitUsedDirectiveFor
775/// is true, as being used with this directive.
776void AsmPrinter::EmitLLVMUsedList(Constant *List) {
777  // Should be an array of 'i8*'.
778  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
779  if (InitList == 0) return;
780
781  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
782    const GlobalValue *GV =
783      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
784    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
785      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
786                                      MCSA_NoDeadStrip);
787  }
788}
789
790/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
791/// function pointers, ignoring the init priority.
792void AsmPrinter::EmitXXStructorList(Constant *List) {
793  // Should be an array of '{ int, void ()* }' structs.  The first value is the
794  // init priority, which we ignore.
795  if (!isa<ConstantArray>(List)) return;
796  ConstantArray *InitList = cast<ConstantArray>(List);
797  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
798    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
799      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
800
801      if (CS->getOperand(1)->isNullValue())
802        return;  // Found a null terminator, exit printing.
803      // Emit the function pointer.
804      EmitGlobalConstant(CS->getOperand(1));
805    }
806}
807
808//===--------------------------------------------------------------------===//
809// Emission and print routines
810//
811
812/// EmitInt8 - Emit a byte directive and value.
813///
814void AsmPrinter::EmitInt8(int Value) const {
815  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
816}
817
818/// EmitInt16 - Emit a short directive and value.
819///
820void AsmPrinter::EmitInt16(int Value) const {
821  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
822}
823
824/// EmitInt32 - Emit a long directive and value.
825///
826void AsmPrinter::EmitInt32(int Value) const {
827  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
828}
829
830/// EmitInt64 - Emit a long long directive and value.
831///
832void AsmPrinter::EmitInt64(uint64_t Value) const {
833  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
834}
835
836//===----------------------------------------------------------------------===//
837
838// EmitAlignment - Emit an alignment directive to the specified power of
839// two boundary.  For example, if you pass in 3 here, you will get an 8
840// byte alignment.  If a global value is specified, and if that global has
841// an explicit alignment requested, it will unconditionally override the
842// alignment request.  However, if ForcedAlignBits is specified, this value
843// has final say: the ultimate alignment will be the max of ForcedAlignBits
844// and the alignment computed with NumBits and the global.
845//
846// The algorithm is:
847//     Align = NumBits;
848//     if (GV && GV->hasalignment) Align = GV->getalignment();
849//     Align = std::max(Align, ForcedAlignBits);
850//
851void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
852                               unsigned ForcedAlignBits,
853                               bool UseFillExpr) const {
854  if (GV && GV->getAlignment())
855    NumBits = Log2_32(GV->getAlignment());
856  NumBits = std::max(NumBits, ForcedAlignBits);
857
858  if (NumBits == 0) return;   // No need to emit alignment.
859
860  unsigned FillValue = 0;
861  if (getCurrentSection()->getKind().isText())
862    FillValue = MAI->getTextAlignFillValue();
863
864  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
865}
866
867/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
868///
869static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
870  MCContext &Ctx = AP.OutContext;
871
872  if (CV->isNullValue() || isa<UndefValue>(CV))
873    return MCConstantExpr::Create(0, Ctx);
874
875  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
876    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
877
878  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
879    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
880  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
881    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
882
883  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
884  if (CE == 0) {
885    llvm_unreachable("Unknown constant value to lower!");
886    return MCConstantExpr::Create(0, Ctx);
887  }
888
889  switch (CE->getOpcode()) {
890  case Instruction::ZExt:
891  case Instruction::SExt:
892  case Instruction::FPTrunc:
893  case Instruction::FPExt:
894  case Instruction::UIToFP:
895  case Instruction::SIToFP:
896  case Instruction::FPToUI:
897  case Instruction::FPToSI:
898  default: llvm_unreachable("FIXME: Don't support this constant cast expr");
899  case Instruction::GetElementPtr: {
900    const TargetData &TD = *AP.TM.getTargetData();
901    // Generate a symbolic expression for the byte address
902    const Constant *PtrVal = CE->getOperand(0);
903    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
904    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
905                                         IdxVec.size());
906
907    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
908    if (Offset == 0)
909      return Base;
910
911    // Truncate/sext the offset to the pointer size.
912    if (TD.getPointerSizeInBits() != 64) {
913      int SExtAmount = 64-TD.getPointerSizeInBits();
914      Offset = (Offset << SExtAmount) >> SExtAmount;
915    }
916
917    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
918                                   Ctx);
919  }
920
921  case Instruction::Trunc:
922    // We emit the value and depend on the assembler to truncate the generated
923    // expression properly.  This is important for differences between
924    // blockaddress labels.  Since the two labels are in the same function, it
925    // is reasonable to treat their delta as a 32-bit value.
926    // FALL THROUGH.
927  case Instruction::BitCast:
928    return LowerConstant(CE->getOperand(0), AP);
929
930  case Instruction::IntToPtr: {
931    const TargetData &TD = *AP.TM.getTargetData();
932    // Handle casts to pointers by changing them into casts to the appropriate
933    // integer type.  This promotes constant folding and simplifies this code.
934    Constant *Op = CE->getOperand(0);
935    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
936                                      false/*ZExt*/);
937    return LowerConstant(Op, AP);
938  }
939
940  case Instruction::PtrToInt: {
941    const TargetData &TD = *AP.TM.getTargetData();
942    // Support only foldable casts to/from pointers that can be eliminated by
943    // changing the pointer to the appropriately sized integer type.
944    Constant *Op = CE->getOperand(0);
945    const Type *Ty = CE->getType();
946
947    const MCExpr *OpExpr = LowerConstant(Op, AP);
948
949    // We can emit the pointer value into this slot if the slot is an
950    // integer slot equal to the size of the pointer.
951    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
952      return OpExpr;
953
954    // Otherwise the pointer is smaller than the resultant integer, mask off
955    // the high bits so we are sure to get a proper truncation if the input is
956    // a constant expr.
957    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
958    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
959    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
960  }
961
962  case Instruction::Add:
963  case Instruction::Sub:
964  case Instruction::And:
965  case Instruction::Or:
966  case Instruction::Xor: {
967    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
968    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
969    switch (CE->getOpcode()) {
970    default: llvm_unreachable("Unknown binary operator constant cast expr");
971    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
972    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
973    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
974    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
975    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
976    }
977  }
978  }
979}
980
981static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
982                                    AsmPrinter &AP) {
983  if (AddrSpace != 0 || !CA->isString()) {
984    // Not a string.  Print the values in successive locations
985    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
986      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
987    return;
988  }
989
990  // Otherwise, it can be emitted as .ascii.
991  SmallVector<char, 128> TmpVec;
992  TmpVec.reserve(CA->getNumOperands());
993  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
994    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
995
996  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
997}
998
999static void EmitGlobalConstantVector(const ConstantVector *CV,
1000                                     unsigned AddrSpace, AsmPrinter &AP) {
1001  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1002    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1003}
1004
1005static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1006                                     unsigned AddrSpace, AsmPrinter &AP) {
1007  // Print the fields in successive locations. Pad to align if needed!
1008  const TargetData *TD = AP.TM.getTargetData();
1009  unsigned Size = TD->getTypeAllocSize(CS->getType());
1010  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1011  uint64_t SizeSoFar = 0;
1012  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1013    const Constant *Field = CS->getOperand(i);
1014
1015    // Check if padding is needed and insert one or more 0s.
1016    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1017    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1018                        - Layout->getElementOffset(i)) - FieldSize;
1019    SizeSoFar += FieldSize + PadSize;
1020
1021    // Now print the actual field value.
1022    AP.EmitGlobalConstant(Field, AddrSpace);
1023
1024    // Insert padding - this may include padding to increase the size of the
1025    // current field up to the ABI size (if the struct is not packed) as well
1026    // as padding to ensure that the next field starts at the right offset.
1027    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1028  }
1029  assert(SizeSoFar == Layout->getSizeInBytes() &&
1030         "Layout of constant struct may be incorrect!");
1031}
1032
1033static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1034                                 AsmPrinter &AP) {
1035  // FP Constants are printed as integer constants to avoid losing
1036  // precision.
1037  if (CFP->getType()->isDoubleTy()) {
1038    if (AP.VerboseAsm) {
1039      double Val = CFP->getValueAPF().convertToDouble();
1040      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1041    }
1042
1043    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1044    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1045    return;
1046  }
1047
1048  if (CFP->getType()->isFloatTy()) {
1049    if (AP.VerboseAsm) {
1050      float Val = CFP->getValueAPF().convertToFloat();
1051      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1052    }
1053    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1054    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1055    return;
1056  }
1057
1058  if (CFP->getType()->isX86_FP80Ty()) {
1059    // all long double variants are printed as hex
1060    // api needed to prevent premature destruction
1061    APInt API = CFP->getValueAPF().bitcastToAPInt();
1062    const uint64_t *p = API.getRawData();
1063    if (AP.VerboseAsm) {
1064      // Convert to double so we can print the approximate val as a comment.
1065      APFloat DoubleVal = CFP->getValueAPF();
1066      bool ignored;
1067      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1068                        &ignored);
1069      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1070        << DoubleVal.convertToDouble() << '\n';
1071    }
1072
1073    if (AP.TM.getTargetData()->isBigEndian()) {
1074      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1075      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1076    } else {
1077      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1078      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1079    }
1080
1081    // Emit the tail padding for the long double.
1082    const TargetData &TD = *AP.TM.getTargetData();
1083    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1084                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1085    return;
1086  }
1087
1088  assert(CFP->getType()->isPPC_FP128Ty() &&
1089         "Floating point constant type not handled");
1090  // All long double variants are printed as hex api needed to prevent
1091  // premature destruction.
1092  APInt API = CFP->getValueAPF().bitcastToAPInt();
1093  const uint64_t *p = API.getRawData();
1094  if (AP.TM.getTargetData()->isBigEndian()) {
1095    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1096    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1097  } else {
1098    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1099    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1100  }
1101}
1102
1103static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1104                                       unsigned AddrSpace, AsmPrinter &AP) {
1105  const TargetData *TD = AP.TM.getTargetData();
1106  unsigned BitWidth = CI->getBitWidth();
1107  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1108
1109  // We don't expect assemblers to support integer data directives
1110  // for more than 64 bits, so we emit the data in at most 64-bit
1111  // quantities at a time.
1112  const uint64_t *RawData = CI->getValue().getRawData();
1113  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1114    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1115    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1116  }
1117}
1118
1119/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1120void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1121  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1122    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1123    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1124    return OutStreamer.EmitZeros(Size, AddrSpace);
1125  }
1126
1127  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1128    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1129    switch (Size) {
1130    case 1:
1131    case 2:
1132    case 4:
1133    case 8:
1134      if (VerboseAsm)
1135        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1136      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1137      return;
1138    default:
1139      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1140      return;
1141    }
1142  }
1143
1144  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1145    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1146
1147  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1148    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1149
1150  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1151    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1152
1153  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1154    return EmitGlobalConstantVector(V, AddrSpace, *this);
1155
1156  if (isa<ConstantPointerNull>(CV)) {
1157    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1158    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1159    return;
1160  }
1161
1162  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1163  // thread the streamer with EmitValue.
1164  OutStreamer.EmitValue(LowerConstant(CV, *this),
1165                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1166                        AddrSpace);
1167}
1168
1169void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1170  // Target doesn't support this yet!
1171  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1172}
1173
1174/// PrintSpecial - Print information related to the specified machine instr
1175/// that is independent of the operand, and may be independent of the instr
1176/// itself.  This can be useful for portably encoding the comment character
1177/// or other bits of target-specific knowledge into the asmstrings.  The
1178/// syntax used is ${:comment}.  Targets can override this to add support
1179/// for their own strange codes.
1180void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1181  if (!strcmp(Code, "private")) {
1182    O << MAI->getPrivateGlobalPrefix();
1183  } else if (!strcmp(Code, "comment")) {
1184    if (VerboseAsm)
1185      O << MAI->getCommentString();
1186  } else if (!strcmp(Code, "uid")) {
1187    // Comparing the address of MI isn't sufficient, because machineinstrs may
1188    // be allocated to the same address across functions.
1189    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1190
1191    // If this is a new LastFn instruction, bump the counter.
1192    if (LastMI != MI || LastFn != ThisF) {
1193      ++Counter;
1194      LastMI = MI;
1195      LastFn = ThisF;
1196    }
1197    O << Counter;
1198  } else {
1199    std::string msg;
1200    raw_string_ostream Msg(msg);
1201    Msg << "Unknown special formatter '" << Code
1202         << "' for machine instr: " << *MI;
1203    llvm_report_error(Msg.str());
1204  }
1205}
1206
1207/// processDebugLoc - Processes the debug information of each machine
1208/// instruction's DebugLoc.
1209void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1210                                 bool BeforePrintingInsn) {
1211  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1212      || !DW->ShouldEmitDwarfDebug())
1213    return;
1214  DebugLoc DL = MI->getDebugLoc();
1215  if (DL.isUnknown())
1216    return;
1217  DILocation CurDLT = MF->getDILocation(DL);
1218  if (CurDLT.getScope().isNull())
1219    return;
1220
1221  if (!BeforePrintingInsn) {
1222    // After printing instruction
1223    DW->EndScope(MI);
1224  } else if (CurDLT.getNode() != PrevDLT) {
1225    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1226                                      CurDLT.getColumnNumber(),
1227                                      CurDLT.getScope().getNode());
1228    printLabel(L);
1229    O << '\n';
1230    DW->BeginScope(MI, L);
1231    PrevDLT = CurDLT.getNode();
1232  }
1233}
1234
1235
1236/// printInlineAsm - This method formats and prints the specified machine
1237/// instruction that is an inline asm.
1238void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1239  unsigned NumOperands = MI->getNumOperands();
1240
1241  // Count the number of register definitions.
1242  unsigned NumDefs = 0;
1243  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1244       ++NumDefs)
1245    assert(NumDefs != NumOperands-1 && "No asm string?");
1246
1247  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1248
1249  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1250  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1251
1252  O << '\t';
1253
1254  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1255  // These are useful to see where empty asm's wound up.
1256  if (AsmStr[0] == 0) {
1257    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1258    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1259    return;
1260  }
1261
1262  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1263
1264  // The variant of the current asmprinter.
1265  int AsmPrinterVariant = MAI->getAssemblerDialect();
1266
1267  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1268  const char *LastEmitted = AsmStr; // One past the last character emitted.
1269
1270  while (*LastEmitted) {
1271    switch (*LastEmitted) {
1272    default: {
1273      // Not a special case, emit the string section literally.
1274      const char *LiteralEnd = LastEmitted+1;
1275      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1276             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1277        ++LiteralEnd;
1278      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1279        O.write(LastEmitted, LiteralEnd-LastEmitted);
1280      LastEmitted = LiteralEnd;
1281      break;
1282    }
1283    case '\n':
1284      ++LastEmitted;   // Consume newline character.
1285      O << '\n';       // Indent code with newline.
1286      break;
1287    case '$': {
1288      ++LastEmitted;   // Consume '$' character.
1289      bool Done = true;
1290
1291      // Handle escapes.
1292      switch (*LastEmitted) {
1293      default: Done = false; break;
1294      case '$':     // $$ -> $
1295        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1296          O << '$';
1297        ++LastEmitted;  // Consume second '$' character.
1298        break;
1299      case '(':             // $( -> same as GCC's { character.
1300        ++LastEmitted;      // Consume '(' character.
1301        if (CurVariant != -1) {
1302          llvm_report_error("Nested variants found in inline asm string: '"
1303                            + std::string(AsmStr) + "'");
1304        }
1305        CurVariant = 0;     // We're in the first variant now.
1306        break;
1307      case '|':
1308        ++LastEmitted;  // consume '|' character.
1309        if (CurVariant == -1)
1310          O << '|';       // this is gcc's behavior for | outside a variant
1311        else
1312          ++CurVariant;   // We're in the next variant.
1313        break;
1314      case ')':         // $) -> same as GCC's } char.
1315        ++LastEmitted;  // consume ')' character.
1316        if (CurVariant == -1)
1317          O << '}';     // this is gcc's behavior for } outside a variant
1318        else
1319          CurVariant = -1;
1320        break;
1321      }
1322      if (Done) break;
1323
1324      bool HasCurlyBraces = false;
1325      if (*LastEmitted == '{') {     // ${variable}
1326        ++LastEmitted;               // Consume '{' character.
1327        HasCurlyBraces = true;
1328      }
1329
1330      // If we have ${:foo}, then this is not a real operand reference, it is a
1331      // "magic" string reference, just like in .td files.  Arrange to call
1332      // PrintSpecial.
1333      if (HasCurlyBraces && *LastEmitted == ':') {
1334        ++LastEmitted;
1335        const char *StrStart = LastEmitted;
1336        const char *StrEnd = strchr(StrStart, '}');
1337        if (StrEnd == 0) {
1338          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1339                            + std::string(AsmStr) + "'");
1340        }
1341
1342        std::string Val(StrStart, StrEnd);
1343        PrintSpecial(MI, Val.c_str());
1344        LastEmitted = StrEnd+1;
1345        break;
1346      }
1347
1348      const char *IDStart = LastEmitted;
1349      char *IDEnd;
1350      errno = 0;
1351      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1352      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1353        llvm_report_error("Bad $ operand number in inline asm string: '"
1354                          + std::string(AsmStr) + "'");
1355      }
1356      LastEmitted = IDEnd;
1357
1358      char Modifier[2] = { 0, 0 };
1359
1360      if (HasCurlyBraces) {
1361        // If we have curly braces, check for a modifier character.  This
1362        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1363        if (*LastEmitted == ':') {
1364          ++LastEmitted;    // Consume ':' character.
1365          if (*LastEmitted == 0) {
1366            llvm_report_error("Bad ${:} expression in inline asm string: '"
1367                              + std::string(AsmStr) + "'");
1368          }
1369
1370          Modifier[0] = *LastEmitted;
1371          ++LastEmitted;    // Consume modifier character.
1372        }
1373
1374        if (*LastEmitted != '}') {
1375          llvm_report_error("Bad ${} expression in inline asm string: '"
1376                            + std::string(AsmStr) + "'");
1377        }
1378        ++LastEmitted;    // Consume '}' character.
1379      }
1380
1381      if ((unsigned)Val >= NumOperands-1) {
1382        llvm_report_error("Invalid $ operand number in inline asm string: '"
1383                          + std::string(AsmStr) + "'");
1384      }
1385
1386      // Okay, we finally have a value number.  Ask the target to print this
1387      // operand!
1388      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1389        unsigned OpNo = 1;
1390
1391        bool Error = false;
1392
1393        // Scan to find the machine operand number for the operand.
1394        for (; Val; --Val) {
1395          if (OpNo >= MI->getNumOperands()) break;
1396          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1397          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1398        }
1399
1400        if (OpNo >= MI->getNumOperands()) {
1401          Error = true;
1402        } else {
1403          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1404          ++OpNo;  // Skip over the ID number.
1405
1406          if (Modifier[0] == 'l')  // labels are target independent
1407            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1408          else {
1409            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1410            if ((OpFlags & 7) == 4) {
1411              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1412                                                Modifier[0] ? Modifier : 0);
1413            } else {
1414              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1415                                          Modifier[0] ? Modifier : 0);
1416            }
1417          }
1418        }
1419        if (Error) {
1420          std::string msg;
1421          raw_string_ostream Msg(msg);
1422          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1423          MI->print(Msg);
1424          llvm_report_error(Msg.str());
1425        }
1426      }
1427      break;
1428    }
1429    }
1430  }
1431  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1432}
1433
1434/// printImplicitDef - This method prints the specified machine instruction
1435/// that is an implicit def.
1436void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1437  if (!VerboseAsm) return;
1438  O.PadToColumn(MAI->getCommentColumn());
1439  O << MAI->getCommentString() << " implicit-def: "
1440    << TRI->getName(MI->getOperand(0).getReg()) << '\n';
1441}
1442
1443void AsmPrinter::printKill(const MachineInstr *MI) const {
1444  if (!VerboseAsm) return;
1445  O.PadToColumn(MAI->getCommentColumn());
1446  O << MAI->getCommentString() << " kill:";
1447  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1448    const MachineOperand &op = MI->getOperand(n);
1449    assert(op.isReg() && "KILL instruction must have only register operands");
1450    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1451  }
1452  O << '\n';
1453}
1454
1455/// printLabel - This method prints a local label used by debug and
1456/// exception handling tables.
1457void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1458  printLabel(MI->getOperand(0).getImm());
1459  O << '\n';
1460}
1461
1462void AsmPrinter::printLabel(unsigned Id) const {
1463  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1464}
1465
1466/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1467/// instruction, using the specified assembler variant.  Targets should
1468/// override this to format as appropriate.
1469bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1470                                 unsigned AsmVariant, const char *ExtraCode) {
1471  // Target doesn't support this yet!
1472  return true;
1473}
1474
1475bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1476                                       unsigned AsmVariant,
1477                                       const char *ExtraCode) {
1478  // Target doesn't support this yet!
1479  return true;
1480}
1481
1482MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1483                                            const char *Suffix) const {
1484  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1485}
1486
1487MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1488                                            const BasicBlock *BB,
1489                                            const char *Suffix) const {
1490  assert(BB->hasName() &&
1491         "Address of anonymous basic block not supported yet!");
1492
1493  // This code must use the function name itself, and not the function number,
1494  // since it must be possible to generate the label name from within other
1495  // functions.
1496  SmallString<60> FnName;
1497  Mang->getNameWithPrefix(FnName, F, false);
1498
1499  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1500  SmallString<60> NameResult;
1501  Mang->getNameWithPrefix(NameResult,
1502                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1503                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1504                          Mangler::Private);
1505
1506  return OutContext.GetOrCreateSymbol(NameResult.str());
1507}
1508
1509/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1510MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1511  SmallString<60> Name;
1512  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1513    << getFunctionNumber() << '_' << CPID;
1514  return OutContext.GetOrCreateSymbol(Name.str());
1515}
1516
1517/// GetJTISymbol - Return the symbol for the specified jump table entry.
1518MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1519  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1520}
1521
1522/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1523/// FIXME: privatize to AsmPrinter.
1524MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1525  SmallString<60> Name;
1526  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1527    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1528  return OutContext.GetOrCreateSymbol(Name.str());
1529}
1530
1531/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1532/// value.
1533MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1534  SmallString<60> NameStr;
1535  Mang->getNameWithPrefix(NameStr, GV, false);
1536  return OutContext.GetOrCreateSymbol(NameStr.str());
1537}
1538
1539/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1540/// global value name as its base, with the specified suffix, and where the
1541/// symbol is forced to have private linkage if ForcePrivate is true.
1542MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1543                                                   StringRef Suffix,
1544                                                   bool ForcePrivate) const {
1545  SmallString<60> NameStr;
1546  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1547  NameStr.append(Suffix.begin(), Suffix.end());
1548  return OutContext.GetOrCreateSymbol(NameStr.str());
1549}
1550
1551/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1552/// ExternalSymbol.
1553MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1554  SmallString<60> NameStr;
1555  Mang->getNameWithPrefix(NameStr, Sym);
1556  return OutContext.GetOrCreateSymbol(NameStr.str());
1557}
1558
1559
1560
1561/// PrintParentLoopComment - Print comments about parent loops of this one.
1562static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1563                                   unsigned FunctionNumber) {
1564  if (Loop == 0) return;
1565  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1566  OS.indent(Loop->getLoopDepth()*2)
1567    << "Parent Loop BB" << FunctionNumber << "_"
1568    << Loop->getHeader()->getNumber()
1569    << " Depth=" << Loop->getLoopDepth() << '\n';
1570}
1571
1572
1573/// PrintChildLoopComment - Print comments about child loops within
1574/// the loop for this basic block, with nesting.
1575static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1576                                  unsigned FunctionNumber) {
1577  // Add child loop information
1578  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1579    OS.indent((*CL)->getLoopDepth()*2)
1580      << "Child Loop BB" << FunctionNumber << "_"
1581      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1582      << '\n';
1583    PrintChildLoopComment(OS, *CL, FunctionNumber);
1584  }
1585}
1586
1587/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1588static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1589                                        const MachineLoopInfo *LI,
1590                                        const AsmPrinter &AP) {
1591  // Add loop depth information
1592  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1593  if (Loop == 0) return;
1594
1595  MachineBasicBlock *Header = Loop->getHeader();
1596  assert(Header && "No header for loop");
1597
1598  // If this block is not a loop header, just print out what is the loop header
1599  // and return.
1600  if (Header != &MBB) {
1601    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1602                              Twine(AP.getFunctionNumber())+"_" +
1603                              Twine(Loop->getHeader()->getNumber())+
1604                              " Depth="+Twine(Loop->getLoopDepth()));
1605    return;
1606  }
1607
1608  // Otherwise, it is a loop header.  Print out information about child and
1609  // parent loops.
1610  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1611
1612  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1613
1614  OS << "=>";
1615  OS.indent(Loop->getLoopDepth()*2-2);
1616
1617  OS << "This ";
1618  if (Loop->empty())
1619    OS << "Inner ";
1620  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1621
1622  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1623}
1624
1625
1626/// EmitBasicBlockStart - This method prints the label for the specified
1627/// MachineBasicBlock, an alignment (if present) and a comment describing
1628/// it if appropriate.
1629void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1630  // Emit an alignment directive for this block, if needed.
1631  if (unsigned Align = MBB->getAlignment())
1632    EmitAlignment(Log2_32(Align));
1633
1634  // If the block has its address taken, emit a special label to satisfy
1635  // references to the block. This is done so that we don't need to
1636  // remember the number of this label, and so that we can make
1637  // forward references to labels without knowing what their numbers
1638  // will be.
1639  if (MBB->hasAddressTaken()) {
1640    const BasicBlock *BB = MBB->getBasicBlock();
1641    if (VerboseAsm)
1642      OutStreamer.AddComment("Address Taken");
1643    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1644  }
1645
1646  // Print the main label for the block.
1647  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1648    if (VerboseAsm) {
1649      // NOTE: Want this comment at start of line.
1650      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1651      if (const BasicBlock *BB = MBB->getBasicBlock())
1652        if (BB->hasName())
1653          OutStreamer.AddComment("%" + BB->getName());
1654
1655      PrintBasicBlockLoopComments(*MBB, LI, *this);
1656      OutStreamer.AddBlankLine();
1657    }
1658  } else {
1659    if (VerboseAsm) {
1660      if (const BasicBlock *BB = MBB->getBasicBlock())
1661        if (BB->hasName())
1662          OutStreamer.AddComment("%" + BB->getName());
1663      PrintBasicBlockLoopComments(*MBB, LI, *this);
1664    }
1665
1666    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1667  }
1668}
1669
1670void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1671  MCSymbolAttr Attr = MCSA_Invalid;
1672
1673  switch (Visibility) {
1674  default: break;
1675  case GlobalValue::HiddenVisibility:
1676    Attr = MAI->getHiddenVisibilityAttr();
1677    break;
1678  case GlobalValue::ProtectedVisibility:
1679    Attr = MAI->getProtectedVisibilityAttr();
1680    break;
1681  }
1682
1683  if (Attr != MCSA_Invalid)
1684    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1685}
1686
1687void AsmPrinter::printOffset(int64_t Offset) const {
1688  if (Offset > 0)
1689    O << '+' << Offset;
1690  else if (Offset < 0)
1691    O << Offset;
1692}
1693
1694GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1695  if (!S->usesMetadata())
1696    return 0;
1697
1698  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1699  if (GCPI != GCMetadataPrinters.end())
1700    return GCPI->second;
1701
1702  const char *Name = S->getName().c_str();
1703
1704  for (GCMetadataPrinterRegistry::iterator
1705         I = GCMetadataPrinterRegistry::begin(),
1706         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1707    if (strcmp(Name, I->getName()) == 0) {
1708      GCMetadataPrinter *GMP = I->instantiate();
1709      GMP->S = S;
1710      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1711      return GMP;
1712    }
1713
1714  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1715  return 0;
1716}
1717
1718/// EmitComments - Pretty-print comments for instructions
1719void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1720  if (!VerboseAsm)
1721    return;
1722
1723  if (!MI.getDebugLoc().isUnknown()) {
1724    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1725
1726    // Print source line info.
1727    O.PadToColumn(MAI->getCommentColumn());
1728    O << MAI->getCommentString() << ' ';
1729    DIScope Scope = DLT.getScope();
1730    // Omit the directory, because it's likely to be long and uninteresting.
1731    if (!Scope.isNull())
1732      O << Scope.getFilename();
1733    else
1734      O << "<unknown>";
1735    O << ':' << DLT.getLineNumber();
1736    if (DLT.getColumnNumber() != 0)
1737      O << ':' << DLT.getColumnNumber();
1738    O << '\n';
1739  }
1740
1741  // Check for spills and reloads
1742  int FI;
1743
1744  const MachineFrameInfo *FrameInfo =
1745    MI.getParent()->getParent()->getFrameInfo();
1746
1747  // We assume a single instruction only has a spill or reload, not
1748  // both.
1749  const MachineMemOperand *MMO;
1750  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1751    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1752      MMO = *MI.memoperands_begin();
1753      O.PadToColumn(MAI->getCommentColumn());
1754      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload\n";
1755    }
1756  }
1757  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1758    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1759      O.PadToColumn(MAI->getCommentColumn());
1760      O << MAI->getCommentString() << ' '
1761        << MMO->getSize() << "-byte Folded Reload\n";
1762    }
1763  }
1764  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1765    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1766      MMO = *MI.memoperands_begin();
1767      O.PadToColumn(MAI->getCommentColumn());
1768      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill\n";
1769    }
1770  }
1771  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1772    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1773      O.PadToColumn(MAI->getCommentColumn());
1774      O << MAI->getCommentString() << ' '
1775        << MMO->getSize() << "-byte Folded Spill\n";
1776    }
1777  }
1778
1779  // Check for spill-induced copies
1780  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1781  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1782                                      SrcSubIdx, DstSubIdx)) {
1783    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1784      O.PadToColumn(MAI->getCommentColumn());
1785      O << MAI->getCommentString() << " Reload Reuse\n";
1786    }
1787  }
1788}
1789
1790