AsmPrinter.cpp revision 5938a3e681ab7612f5921c5ccaca5d2e0851c60f 
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AsmPrinter class.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "asm-printer"
15#include "llvm/CodeGen/AsmPrinter.h"
16#include "llvm/Assembly/Writer.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constants.h"
19#include "llvm/Module.h"
20#include "llvm/CodeGen/DwarfWriter.h"
21#include "llvm/CodeGen/GCMetadataPrinter.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineFunction.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineLoopInfo.h"
27#include "llvm/CodeGen/MachineModuleInfo.h"
28#include "llvm/Analysis/ConstantFolding.h"
29#include "llvm/Analysis/DebugInfo.h"
30#include "llvm/MC/MCContext.h"
31#include "llvm/MC/MCExpr.h"
32#include "llvm/MC/MCInst.h"
33#include "llvm/MC/MCSection.h"
34#include "llvm/MC/MCStreamer.h"
35#include "llvm/MC/MCSymbol.h"
36#include "llvm/MC/MCAsmInfo.h"
37#include "llvm/Target/Mangler.h"
38#include "llvm/Target/TargetData.h"
39#include "llvm/Target/TargetInstrInfo.h"
40#include "llvm/Target/TargetLowering.h"
41#include "llvm/Target/TargetLoweringObjectFile.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/Target/TargetRegisterInfo.h"
44#include "llvm/ADT/SmallPtrSet.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/ADT/Statistic.h"
47#include "llvm/Support/CommandLine.h"
48#include "llvm/Support/Debug.h"
49#include "llvm/Support/ErrorHandling.h"
50#include "llvm/Support/Format.h"
51#include "llvm/Support/FormattedStream.h"
52#include <cerrno>
53using namespace llvm;
54
55STATISTIC(EmittedInsts, "Number of machine instrs printed");
56
57char AsmPrinter::ID = 0;
58AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
59                       MCContext &Ctx, MCStreamer &Streamer,
60                       const MCAsmInfo *T)
61  : MachineFunctionPass(&ID), O(o),
62    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
63    OutContext(Ctx), OutStreamer(Streamer),
64    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
65  DW = 0; MMI = 0;
66  VerboseAsm = Streamer.isVerboseAsm();
67}
68
69AsmPrinter::~AsmPrinter() {
70  for (gcp_iterator I = GCMetadataPrinters.begin(),
71                    E = GCMetadataPrinters.end(); I != E; ++I)
72    delete I->second;
73
74  delete &OutStreamer;
75  delete &OutContext;
76}
77
78/// getFunctionNumber - Return a unique ID for the current function.
79///
80unsigned AsmPrinter::getFunctionNumber() const {
81  return MF->getFunctionNumber();
82}
83
84TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
85  return TM.getTargetLowering()->getObjFileLowering();
86}
87
88/// getCurrentSection() - Return the current section we are emitting to.
89const MCSection *AsmPrinter::getCurrentSection() const {
90  return OutStreamer.getCurrentSection();
91}
92
93
94void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
95  AU.setPreservesAll();
96  MachineFunctionPass::getAnalysisUsage(AU);
97  AU.addRequired<GCModuleInfo>();
98  if (VerboseAsm)
99    AU.addRequired<MachineLoopInfo>();
100}
101
102bool AsmPrinter::doInitialization(Module &M) {
103  // Initialize TargetLoweringObjectFile.
104  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
105    .Initialize(OutContext, TM);
106
107  Mang = new Mangler(*MAI);
108
109  // Allow the target to emit any magic that it wants at the start of the file.
110  EmitStartOfAsmFile(M);
111
112  // Very minimal debug info. It is ignored if we emit actual debug info. If we
113  // don't, this at least helps the user find where a global came from.
114  if (MAI->hasSingleParameterDotFile()) {
115    // .file "foo.c"
116    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
117  }
118
119  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
120  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
121  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
122    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
123      MP->beginAssembly(O, *this, *MAI);
124
125  if (!M.getModuleInlineAsm().empty())
126    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
127      << M.getModuleInlineAsm()
128      << '\n' << MAI->getCommentString()
129      << " End of file scope inline assembly\n";
130
131  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
132  if (MMI)
133    MMI->AnalyzeModule(M);
134  DW = getAnalysisIfAvailable<DwarfWriter>();
135  if (DW)
136    DW->BeginModule(&M, MMI, O, this, MAI);
137
138  return false;
139}
140
141void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
142  switch ((GlobalValue::LinkageTypes)Linkage) {
143  case GlobalValue::CommonLinkage:
144  case GlobalValue::LinkOnceAnyLinkage:
145  case GlobalValue::LinkOnceODRLinkage:
146  case GlobalValue::WeakAnyLinkage:
147  case GlobalValue::WeakODRLinkage:
148  case GlobalValue::LinkerPrivateLinkage:
149    if (MAI->getWeakDefDirective() != 0) {
150      // .globl _foo
151      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
152      // .weak_definition _foo
153      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
154    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
155      // .globl _foo
156      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
157      // FIXME: linkonce should be a section attribute, handled by COFF Section
158      // assignment.
159      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
160      // .linkonce discard
161      // FIXME: It would be nice to use .linkonce samesize for non-common
162      // globals.
163      O << LinkOnce;
164    } else {
165      // .weak _foo
166      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
167    }
168    break;
169  case GlobalValue::DLLExportLinkage:
170  case GlobalValue::AppendingLinkage:
171    // FIXME: appending linkage variables should go into a section of
172    // their name or something.  For now, just emit them as external.
173  case GlobalValue::ExternalLinkage:
174    // If external or appending, declare as a global symbol.
175    // .globl _foo
176    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
177    break;
178  case GlobalValue::PrivateLinkage:
179  case GlobalValue::InternalLinkage:
180    break;
181  default:
182    llvm_unreachable("Unknown linkage type!");
183  }
184}
185
186
187/// EmitGlobalVariable - Emit the specified global variable to the .s file.
188void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
189  if (!GV->hasInitializer())   // External globals require no code.
190    return;
191
192  // Check to see if this is a special global used by LLVM, if so, emit it.
193  if (EmitSpecialLLVMGlobal(GV))
194    return;
195
196  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
197  EmitVisibility(GVSym, GV->getVisibility());
198
199  if (MAI->hasDotTypeDotSizeDirective())
200    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
201
202  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
203
204  const TargetData *TD = TM.getTargetData();
205  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
206  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
207
208  // Handle common and BSS local symbols (.lcomm).
209  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
210    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
211
212    if (VerboseAsm) {
213      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
214                     /*PrintType=*/false, GV->getParent());
215      OutStreamer.GetCommentOS() << '\n';
216    }
217
218    // Handle common symbols.
219    if (GVKind.isCommon()) {
220      // .comm _foo, 42, 4
221      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
222      return;
223    }
224
225    // Handle local BSS symbols.
226    if (MAI->hasMachoZeroFillDirective()) {
227      const MCSection *TheSection =
228        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
229      // .zerofill __DATA, __bss, _foo, 400, 5
230      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
231      return;
232    }
233
234    if (MAI->hasLCOMMDirective()) {
235      // .lcomm _foo, 42
236      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
237      return;
238    }
239
240    // .local _foo
241    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
242    // .comm _foo, 42, 4
243    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
244    return;
245  }
246
247  const MCSection *TheSection =
248    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
249
250  // Handle the zerofill directive on darwin, which is a special form of BSS
251  // emission.
252  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
253    // .globl _foo
254    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
255    // .zerofill __DATA, __common, _foo, 400, 5
256    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
257    return;
258  }
259
260  OutStreamer.SwitchSection(TheSection);
261
262  EmitLinkage(GV->getLinkage(), GVSym);
263  EmitAlignment(AlignLog, GV);
264
265  if (VerboseAsm) {
266    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
267                   /*PrintType=*/false, GV->getParent());
268    OutStreamer.GetCommentOS() << '\n';
269  }
270  OutStreamer.EmitLabel(GVSym);
271
272  EmitGlobalConstant(GV->getInitializer());
273
274  if (MAI->hasDotTypeDotSizeDirective())
275    // .size foo, 42
276    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
277
278  OutStreamer.AddBlankLine();
279}
280
281/// EmitFunctionHeader - This method emits the header for the current
282/// function.
283void AsmPrinter::EmitFunctionHeader() {
284  // Print out constants referenced by the function
285  EmitConstantPool();
286
287  // Print the 'header' of function.
288  const Function *F = MF->getFunction();
289
290  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
291  EmitVisibility(CurrentFnSym, F->getVisibility());
292
293  EmitLinkage(F->getLinkage(), CurrentFnSym);
294  EmitAlignment(MF->getAlignment(), F);
295
296  if (MAI->hasDotTypeDotSizeDirective())
297    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
298
299  if (VerboseAsm) {
300    WriteAsOperand(OutStreamer.GetCommentOS(), F,
301                   /*PrintType=*/false, F->getParent());
302    OutStreamer.GetCommentOS() << '\n';
303  }
304
305  // Emit the CurrentFnSym.  This is is a virtual function to allow targets to
306  // do their wild and crazy things as required.
307  EmitFunctionEntryLabel();
308
309  // Add some workaround for linkonce linkage on Cygwin\MinGW.
310  if (MAI->getLinkOnceDirective() != 0 &&
311      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
312    // FIXME: What is this?
313    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
314
315  // Emit pre-function debug and/or EH information.
316  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
317    DW->BeginFunction(MF);
318}
319
320/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
321/// function.  This can be overridden by targets as required to do custom stuff.
322void AsmPrinter::EmitFunctionEntryLabel() {
323  OutStreamer.EmitLabel(CurrentFnSym);
324}
325
326
327/// EmitFunctionBody - This method emits the body and trailer for a
328/// function.
329void AsmPrinter::EmitFunctionBody() {
330  // Emit target-specific gunk before the function body.
331  EmitFunctionBodyStart();
332
333  // Print out code for the function.
334  bool HasAnyRealCode = false;
335  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
336       I != E; ++I) {
337    // Print a label for the basic block.
338    EmitBasicBlockStart(I);
339    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
340         II != IE; ++II) {
341      // Print the assembly for the instruction.
342      if (!II->isLabel())
343        HasAnyRealCode = true;
344
345      ++EmittedInsts;
346
347      // FIXME: Clean up processDebugLoc.
348      processDebugLoc(II, true);
349
350      switch (II->getOpcode()) {
351      case TargetInstrInfo::DBG_LABEL:
352      case TargetInstrInfo::EH_LABEL:
353      case TargetInstrInfo::GC_LABEL:
354        printLabelInst(II);
355        break;
356      case TargetInstrInfo::INLINEASM:
357        printInlineAsm(II);
358        break;
359      case TargetInstrInfo::IMPLICIT_DEF:
360        printImplicitDef(II);
361        break;
362      case TargetInstrInfo::KILL:
363        printKill(II);
364        break;
365      default:
366        EmitInstruction(II);
367        break;
368      }
369      if (VerboseAsm)
370        EmitComments(*II);
371
372      // FIXME: Clean up processDebugLoc.
373      processDebugLoc(II, false);
374    }
375  }
376
377  // If the function is empty and the object file uses .subsections_via_symbols,
378  // then we need to emit *something* to the function body to prevent the
379  // labels from collapsing together.  Just emit a 0 byte.
380  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
381    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
382
383  // Emit target-specific gunk after the function body.
384  EmitFunctionBodyEnd();
385
386  if (MAI->hasDotTypeDotSizeDirective())
387    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
388
389  // Emit post-function debug information.
390  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
391    DW->EndFunction(MF);
392
393  // Print out jump tables referenced by the function.
394  EmitJumpTableInfo();
395
396  OutStreamer.AddBlankLine();
397}
398
399
400bool AsmPrinter::doFinalization(Module &M) {
401  // Emit global variables.
402  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
403       I != E; ++I)
404    EmitGlobalVariable(I);
405
406  // Emit final debug information.
407  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
408    DW->EndModule();
409
410  // If the target wants to know about weak references, print them all.
411  if (MAI->getWeakRefDirective()) {
412    // FIXME: This is not lazy, it would be nice to only print weak references
413    // to stuff that is actually used.  Note that doing so would require targets
414    // to notice uses in operands (due to constant exprs etc).  This should
415    // happen with the MC stuff eventually.
416
417    // Print out module-level global variables here.
418    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
419         I != E; ++I) {
420      if (!I->hasExternalWeakLinkage()) continue;
421      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
422                                      MCSA_WeakReference);
423    }
424
425    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
426      if (!I->hasExternalWeakLinkage()) continue;
427      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
428                                      MCSA_WeakReference);
429    }
430  }
431
432  if (MAI->hasSetDirective()) {
433    OutStreamer.AddBlankLine();
434    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
435         I != E; ++I) {
436      MCSymbol *Name = GetGlobalValueSymbol(I);
437
438      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
439      MCSymbol *Target = GetGlobalValueSymbol(GV);
440
441      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
442        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
443      else if (I->hasWeakLinkage())
444        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
445      else
446        assert(I->hasLocalLinkage() && "Invalid alias linkage");
447
448      EmitVisibility(Name, I->getVisibility());
449
450      // Emit the directives as assignments aka .set:
451      OutStreamer.EmitAssignment(Name,
452                                 MCSymbolRefExpr::Create(Target, OutContext));
453    }
454  }
455
456  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
457  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
458  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
459    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
460      MP->finishAssembly(O, *this, *MAI);
461
462  // If we don't have any trampolines, then we don't require stack memory
463  // to be executable. Some targets have a directive to declare this.
464  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
465  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
466    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
467      OutStreamer.SwitchSection(S);
468
469  // Allow the target to emit any magic that it wants at the end of the file,
470  // after everything else has gone out.
471  EmitEndOfAsmFile(M);
472
473  delete Mang; Mang = 0;
474  DW = 0; MMI = 0;
475
476  OutStreamer.Finish();
477  return false;
478}
479
480void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
481  this->MF = &MF;
482  // Get the function symbol.
483  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
484
485  if (VerboseAsm)
486    LI = &getAnalysis<MachineLoopInfo>();
487}
488
489namespace {
490  // SectionCPs - Keep track the alignment, constpool entries per Section.
491  struct SectionCPs {
492    const MCSection *S;
493    unsigned Alignment;
494    SmallVector<unsigned, 4> CPEs;
495    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
496  };
497}
498
499/// EmitConstantPool - Print to the current output stream assembly
500/// representations of the constants in the constant pool MCP. This is
501/// used to print out constants which have been "spilled to memory" by
502/// the code generator.
503///
504void AsmPrinter::EmitConstantPool() {
505  const MachineConstantPool *MCP = MF->getConstantPool();
506  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
507  if (CP.empty()) return;
508
509  // Calculate sections for constant pool entries. We collect entries to go into
510  // the same section together to reduce amount of section switch statements.
511  SmallVector<SectionCPs, 4> CPSections;
512  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
513    const MachineConstantPoolEntry &CPE = CP[i];
514    unsigned Align = CPE.getAlignment();
515
516    SectionKind Kind;
517    switch (CPE.getRelocationInfo()) {
518    default: llvm_unreachable("Unknown section kind");
519    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
520    case 1:
521      Kind = SectionKind::getReadOnlyWithRelLocal();
522      break;
523    case 0:
524    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
525    case 4:  Kind = SectionKind::getMergeableConst4(); break;
526    case 8:  Kind = SectionKind::getMergeableConst8(); break;
527    case 16: Kind = SectionKind::getMergeableConst16();break;
528    default: Kind = SectionKind::getMergeableConst(); break;
529    }
530    }
531
532    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
533
534    // The number of sections are small, just do a linear search from the
535    // last section to the first.
536    bool Found = false;
537    unsigned SecIdx = CPSections.size();
538    while (SecIdx != 0) {
539      if (CPSections[--SecIdx].S == S) {
540        Found = true;
541        break;
542      }
543    }
544    if (!Found) {
545      SecIdx = CPSections.size();
546      CPSections.push_back(SectionCPs(S, Align));
547    }
548
549    if (Align > CPSections[SecIdx].Alignment)
550      CPSections[SecIdx].Alignment = Align;
551    CPSections[SecIdx].CPEs.push_back(i);
552  }
553
554  // Now print stuff into the calculated sections.
555  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
556    OutStreamer.SwitchSection(CPSections[i].S);
557    EmitAlignment(Log2_32(CPSections[i].Alignment));
558
559    unsigned Offset = 0;
560    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
561      unsigned CPI = CPSections[i].CPEs[j];
562      MachineConstantPoolEntry CPE = CP[CPI];
563
564      // Emit inter-object padding for alignment.
565      unsigned AlignMask = CPE.getAlignment() - 1;
566      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
567      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
568
569      const Type *Ty = CPE.getType();
570      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
571
572      // Emit the label with a comment on it.
573      if (VerboseAsm) {
574        OutStreamer.GetCommentOS() << "constant pool ";
575        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
576                          MF->getFunction()->getParent());
577        OutStreamer.GetCommentOS() << '\n';
578      }
579      OutStreamer.EmitLabel(GetCPISymbol(CPI));
580
581      if (CPE.isMachineConstantPoolEntry())
582        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
583      else
584        EmitGlobalConstant(CPE.Val.ConstVal);
585    }
586  }
587}
588
589/// EmitJumpTableInfo - Print assembly representations of the jump tables used
590/// by the current function to the current output stream.
591///
592void AsmPrinter::EmitJumpTableInfo() {
593  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
594  if (MJTI == 0) return;
595  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
596  if (JT.empty()) return;
597
598  // Pick the directive to use to print the jump table entries, and switch to
599  // the appropriate section.
600  const Function *F = MF->getFunction();
601  bool JTInDiffSection = false;
602  if (// In PIC mode, we need to emit the jump table to the same section as the
603      // function body itself, otherwise the label differences won't make sense.
604      // FIXME: Need a better predicate for this: what about custom entries?
605      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
606      // We should also do if the section name is NULL or function is declared
607      // in discardable section
608      // FIXME: this isn't the right predicate, should be based on the MCSection
609      // for the function.
610      F->isWeakForLinker()) {
611    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
612  } else {
613    // Otherwise, drop it in the readonly section.
614    const MCSection *ReadOnlySection =
615      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
616    OutStreamer.SwitchSection(ReadOnlySection);
617    JTInDiffSection = true;
618  }
619
620  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
621
622  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
623    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
624
625    // If this jump table was deleted, ignore it.
626    if (JTBBs.empty()) continue;
627
628    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
629    // .set directive for each unique entry.  This reduces the number of
630    // relocations the assembler will generate for the jump table.
631    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
632        MAI->hasSetDirective()) {
633      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
634      const TargetLowering *TLI = TM.getTargetLowering();
635      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
636      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
637        const MachineBasicBlock *MBB = JTBBs[ii];
638        if (!EmittedSets.insert(MBB)) continue;
639
640        // .set LJTSet, LBB32-base
641        const MCExpr *LHS =
642          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
643        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
644                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
645      }
646    }
647
648    // On some targets (e.g. Darwin) we want to emit two consequtive labels
649    // before each jump table.  The first label is never referenced, but tells
650    // the assembler and linker the extents of the jump table object.  The
651    // second label is actually referenced by the code.
652    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
653      // FIXME: This doesn't have to have any specific name, just any randomly
654      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
655      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
656
657    OutStreamer.EmitLabel(GetJTISymbol(JTI));
658
659    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
660      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
661  }
662}
663
664/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
665/// current stream.
666void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
667                                    const MachineBasicBlock *MBB,
668                                    unsigned UID) const {
669  const MCExpr *Value = 0;
670  switch (MJTI->getEntryKind()) {
671  case MachineJumpTableInfo::EK_Custom32:
672    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
673                                                              OutContext);
674    break;
675  case MachineJumpTableInfo::EK_BlockAddress:
676    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
677    //     .word LBB123
678    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
679    break;
680  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
681    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
682    // with a relocation as gp-relative, e.g.:
683    //     .gprel32 LBB123
684    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
685    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
686    return;
687  }
688
689  case MachineJumpTableInfo::EK_LabelDifference32: {
690    // EK_LabelDifference32 - Each entry is the address of the block minus
691    // the address of the jump table.  This is used for PIC jump tables where
692    // gprel32 is not supported.  e.g.:
693    //      .word LBB123 - LJTI1_2
694    // If the .set directive is supported, this is emitted as:
695    //      .set L4_5_set_123, LBB123 - LJTI1_2
696    //      .word L4_5_set_123
697
698    // If we have emitted set directives for the jump table entries, print
699    // them rather than the entries themselves.  If we're emitting PIC, then
700    // emit the table entries as differences between two text section labels.
701    if (MAI->hasSetDirective()) {
702      // If we used .set, reference the .set's symbol.
703      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
704                                      OutContext);
705      break;
706    }
707    // Otherwise, use the difference as the jump table entry.
708    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
709    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
710    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
711    break;
712  }
713  }
714
715  assert(Value && "Unknown entry kind!");
716
717  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
718  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
719}
720
721
722/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
723/// special global used by LLVM.  If so, emit it and return true, otherwise
724/// do nothing and return false.
725bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
726  if (GV->getName() == "llvm.used") {
727    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
728      EmitLLVMUsedList(GV->getInitializer());
729    return true;
730  }
731
732  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
733  if (GV->getSection() == "llvm.metadata" ||
734      GV->hasAvailableExternallyLinkage())
735    return true;
736
737  if (!GV->hasAppendingLinkage()) return false;
738
739  assert(GV->hasInitializer() && "Not a special LLVM global!");
740
741  const TargetData *TD = TM.getTargetData();
742  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
743  if (GV->getName() == "llvm.global_ctors") {
744    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
745    EmitAlignment(Align, 0);
746    EmitXXStructorList(GV->getInitializer());
747
748    if (TM.getRelocationModel() == Reloc::Static &&
749        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
750      StringRef Sym(".constructors_used");
751      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
752                                      MCSA_Reference);
753    }
754    return true;
755  }
756
757  if (GV->getName() == "llvm.global_dtors") {
758    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
759    EmitAlignment(Align, 0);
760    EmitXXStructorList(GV->getInitializer());
761
762    if (TM.getRelocationModel() == Reloc::Static &&
763        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
764      StringRef Sym(".destructors_used");
765      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
766                                      MCSA_Reference);
767    }
768    return true;
769  }
770
771  return false;
772}
773
774/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
775/// global in the specified llvm.used list for which emitUsedDirectiveFor
776/// is true, as being used with this directive.
777void AsmPrinter::EmitLLVMUsedList(Constant *List) {
778  // Should be an array of 'i8*'.
779  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
780  if (InitList == 0) return;
781
782  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
783    const GlobalValue *GV =
784      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
785    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
786      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
787                                      MCSA_NoDeadStrip);
788  }
789}
790
791/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
792/// function pointers, ignoring the init priority.
793void AsmPrinter::EmitXXStructorList(Constant *List) {
794  // Should be an array of '{ int, void ()* }' structs.  The first value is the
795  // init priority, which we ignore.
796  if (!isa<ConstantArray>(List)) return;
797  ConstantArray *InitList = cast<ConstantArray>(List);
798  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
799    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
800      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
801
802      if (CS->getOperand(1)->isNullValue())
803        return;  // Found a null terminator, exit printing.
804      // Emit the function pointer.
805      EmitGlobalConstant(CS->getOperand(1));
806    }
807}
808
809//===--------------------------------------------------------------------===//
810// Emission and print routines
811//
812
813/// EmitInt8 - Emit a byte directive and value.
814///
815void AsmPrinter::EmitInt8(int Value) const {
816  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
817}
818
819/// EmitInt16 - Emit a short directive and value.
820///
821void AsmPrinter::EmitInt16(int Value) const {
822  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
823}
824
825/// EmitInt32 - Emit a long directive and value.
826///
827void AsmPrinter::EmitInt32(int Value) const {
828  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
829}
830
831/// EmitInt64 - Emit a long long directive and value.
832///
833void AsmPrinter::EmitInt64(uint64_t Value) const {
834  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
835}
836
837//===----------------------------------------------------------------------===//
838
839// EmitAlignment - Emit an alignment directive to the specified power of
840// two boundary.  For example, if you pass in 3 here, you will get an 8
841// byte alignment.  If a global value is specified, and if that global has
842// an explicit alignment requested, it will unconditionally override the
843// alignment request.  However, if ForcedAlignBits is specified, this value
844// has final say: the ultimate alignment will be the max of ForcedAlignBits
845// and the alignment computed with NumBits and the global.
846//
847// The algorithm is:
848//     Align = NumBits;
849//     if (GV && GV->hasalignment) Align = GV->getalignment();
850//     Align = std::max(Align, ForcedAlignBits);
851//
852void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
853                               unsigned ForcedAlignBits,
854                               bool UseFillExpr) const {
855  if (GV && GV->getAlignment())
856    NumBits = Log2_32(GV->getAlignment());
857  NumBits = std::max(NumBits, ForcedAlignBits);
858
859  if (NumBits == 0) return;   // No need to emit alignment.
860
861  unsigned FillValue = 0;
862  if (getCurrentSection()->getKind().isText())
863    FillValue = MAI->getTextAlignFillValue();
864
865  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
866}
867
868/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
869///
870static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
871  MCContext &Ctx = AP.OutContext;
872
873  if (CV->isNullValue() || isa<UndefValue>(CV))
874    return MCConstantExpr::Create(0, Ctx);
875
876  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
877    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
878
879  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
880    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
881  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
882    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
883
884  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
885  if (CE == 0) {
886    llvm_unreachable("Unknown constant value to lower!");
887    return MCConstantExpr::Create(0, Ctx);
888  }
889
890  switch (CE->getOpcode()) {
891  default:
892    // If the code isn't optimized, there may be outstanding folding
893    // opportunities. Attempt to fold the expression using TargetData as a
894    // last resort before giving up.
895    if (Constant *C =
896          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
897      if (C != CE)
898        return LowerConstant(C, AP);
899#ifndef NDEBUG
900    CE->dump();
901#endif
902    llvm_unreachable("FIXME: Don't support this constant expr");
903  case Instruction::GetElementPtr: {
904    const TargetData &TD = *AP.TM.getTargetData();
905    // Generate a symbolic expression for the byte address
906    const Constant *PtrVal = CE->getOperand(0);
907    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
908    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
909                                         IdxVec.size());
910
911    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
912    if (Offset == 0)
913      return Base;
914
915    // Truncate/sext the offset to the pointer size.
916    if (TD.getPointerSizeInBits() != 64) {
917      int SExtAmount = 64-TD.getPointerSizeInBits();
918      Offset = (Offset << SExtAmount) >> SExtAmount;
919    }
920
921    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
922                                   Ctx);
923  }
924
925  case Instruction::Trunc:
926    // We emit the value and depend on the assembler to truncate the generated
927    // expression properly.  This is important for differences between
928    // blockaddress labels.  Since the two labels are in the same function, it
929    // is reasonable to treat their delta as a 32-bit value.
930    // FALL THROUGH.
931  case Instruction::BitCast:
932    return LowerConstant(CE->getOperand(0), AP);
933
934  case Instruction::IntToPtr: {
935    const TargetData &TD = *AP.TM.getTargetData();
936    // Handle casts to pointers by changing them into casts to the appropriate
937    // integer type.  This promotes constant folding and simplifies this code.
938    Constant *Op = CE->getOperand(0);
939    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
940                                      false/*ZExt*/);
941    return LowerConstant(Op, AP);
942  }
943
944  case Instruction::PtrToInt: {
945    const TargetData &TD = *AP.TM.getTargetData();
946    // Support only foldable casts to/from pointers that can be eliminated by
947    // changing the pointer to the appropriately sized integer type.
948    Constant *Op = CE->getOperand(0);
949    const Type *Ty = CE->getType();
950
951    const MCExpr *OpExpr = LowerConstant(Op, AP);
952
953    // We can emit the pointer value into this slot if the slot is an
954    // integer slot equal to the size of the pointer.
955    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
956      return OpExpr;
957
958    // Otherwise the pointer is smaller than the resultant integer, mask off
959    // the high bits so we are sure to get a proper truncation if the input is
960    // a constant expr.
961    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
962    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
963    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
964  }
965
966  // The MC library also has a right-shift operator, but it isn't consistently
967  // signed or unsigned between different targets.
968  case Instruction::Add:
969  case Instruction::Sub:
970  case Instruction::Mul:
971  case Instruction::SDiv:
972  case Instruction::SRem:
973  case Instruction::Shl:
974  case Instruction::And:
975  case Instruction::Or:
976  case Instruction::Xor: {
977    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
978    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
979    switch (CE->getOpcode()) {
980    default: llvm_unreachable("Unknown binary operator constant cast expr");
981    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
982    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
983    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
984    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
985    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
986    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
987    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
988    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
989    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
990    }
991  }
992  }
993}
994
995static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
996                                    AsmPrinter &AP) {
997  if (AddrSpace != 0 || !CA->isString()) {
998    // Not a string.  Print the values in successive locations
999    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1000      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1001    return;
1002  }
1003
1004  // Otherwise, it can be emitted as .ascii.
1005  SmallVector<char, 128> TmpVec;
1006  TmpVec.reserve(CA->getNumOperands());
1007  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1008    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1009
1010  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1011}
1012
1013static void EmitGlobalConstantVector(const ConstantVector *CV,
1014                                     unsigned AddrSpace, AsmPrinter &AP) {
1015  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1016    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1017}
1018
1019static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1020                                     unsigned AddrSpace, AsmPrinter &AP) {
1021  // Print the fields in successive locations. Pad to align if needed!
1022  const TargetData *TD = AP.TM.getTargetData();
1023  unsigned Size = TD->getTypeAllocSize(CS->getType());
1024  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1025  uint64_t SizeSoFar = 0;
1026  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1027    const Constant *Field = CS->getOperand(i);
1028
1029    // Check if padding is needed and insert one or more 0s.
1030    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1031    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1032                        - Layout->getElementOffset(i)) - FieldSize;
1033    SizeSoFar += FieldSize + PadSize;
1034
1035    // Now print the actual field value.
1036    AP.EmitGlobalConstant(Field, AddrSpace);
1037
1038    // Insert padding - this may include padding to increase the size of the
1039    // current field up to the ABI size (if the struct is not packed) as well
1040    // as padding to ensure that the next field starts at the right offset.
1041    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1042  }
1043  assert(SizeSoFar == Layout->getSizeInBytes() &&
1044         "Layout of constant struct may be incorrect!");
1045}
1046
1047static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1048                                 AsmPrinter &AP) {
1049  // FP Constants are printed as integer constants to avoid losing
1050  // precision.
1051  if (CFP->getType()->isDoubleTy()) {
1052    if (AP.VerboseAsm) {
1053      double Val = CFP->getValueAPF().convertToDouble();
1054      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1055    }
1056
1057    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1058    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1059    return;
1060  }
1061
1062  if (CFP->getType()->isFloatTy()) {
1063    if (AP.VerboseAsm) {
1064      float Val = CFP->getValueAPF().convertToFloat();
1065      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1066    }
1067    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1068    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1069    return;
1070  }
1071
1072  if (CFP->getType()->isX86_FP80Ty()) {
1073    // all long double variants are printed as hex
1074    // api needed to prevent premature destruction
1075    APInt API = CFP->getValueAPF().bitcastToAPInt();
1076    const uint64_t *p = API.getRawData();
1077    if (AP.VerboseAsm) {
1078      // Convert to double so we can print the approximate val as a comment.
1079      APFloat DoubleVal = CFP->getValueAPF();
1080      bool ignored;
1081      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1082                        &ignored);
1083      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1084        << DoubleVal.convertToDouble() << '\n';
1085    }
1086
1087    if (AP.TM.getTargetData()->isBigEndian()) {
1088      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1089      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1090    } else {
1091      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1092      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1093    }
1094
1095    // Emit the tail padding for the long double.
1096    const TargetData &TD = *AP.TM.getTargetData();
1097    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1098                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1099    return;
1100  }
1101
1102  assert(CFP->getType()->isPPC_FP128Ty() &&
1103         "Floating point constant type not handled");
1104  // All long double variants are printed as hex api needed to prevent
1105  // premature destruction.
1106  APInt API = CFP->getValueAPF().bitcastToAPInt();
1107  const uint64_t *p = API.getRawData();
1108  if (AP.TM.getTargetData()->isBigEndian()) {
1109    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1110    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1111  } else {
1112    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1113    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1114  }
1115}
1116
1117static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1118                                       unsigned AddrSpace, AsmPrinter &AP) {
1119  const TargetData *TD = AP.TM.getTargetData();
1120  unsigned BitWidth = CI->getBitWidth();
1121  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1122
1123  // We don't expect assemblers to support integer data directives
1124  // for more than 64 bits, so we emit the data in at most 64-bit
1125  // quantities at a time.
1126  const uint64_t *RawData = CI->getValue().getRawData();
1127  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1128    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1129    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1130  }
1131}
1132
1133/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1134void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1135  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1136    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1137    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1138    return OutStreamer.EmitZeros(Size, AddrSpace);
1139  }
1140
1141  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1142    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1143    switch (Size) {
1144    case 1:
1145    case 2:
1146    case 4:
1147    case 8:
1148      if (VerboseAsm)
1149        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1150      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1151      return;
1152    default:
1153      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1154      return;
1155    }
1156  }
1157
1158  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1159    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1160
1161  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1162    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1163
1164  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1165    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1166
1167  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1168    return EmitGlobalConstantVector(V, AddrSpace, *this);
1169
1170  if (isa<ConstantPointerNull>(CV)) {
1171    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1172    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1173    return;
1174  }
1175
1176  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1177  // thread the streamer with EmitValue.
1178  OutStreamer.EmitValue(LowerConstant(CV, *this),
1179                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1180                        AddrSpace);
1181}
1182
1183void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1184  // Target doesn't support this yet!
1185  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1186}
1187
1188/// PrintSpecial - Print information related to the specified machine instr
1189/// that is independent of the operand, and may be independent of the instr
1190/// itself.  This can be useful for portably encoding the comment character
1191/// or other bits of target-specific knowledge into the asmstrings.  The
1192/// syntax used is ${:comment}.  Targets can override this to add support
1193/// for their own strange codes.
1194void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1195  if (!strcmp(Code, "private")) {
1196    O << MAI->getPrivateGlobalPrefix();
1197  } else if (!strcmp(Code, "comment")) {
1198    if (VerboseAsm)
1199      O << MAI->getCommentString();
1200  } else if (!strcmp(Code, "uid")) {
1201    // Comparing the address of MI isn't sufficient, because machineinstrs may
1202    // be allocated to the same address across functions.
1203    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1204
1205    // If this is a new LastFn instruction, bump the counter.
1206    if (LastMI != MI || LastFn != ThisF) {
1207      ++Counter;
1208      LastMI = MI;
1209      LastFn = ThisF;
1210    }
1211    O << Counter;
1212  } else {
1213    std::string msg;
1214    raw_string_ostream Msg(msg);
1215    Msg << "Unknown special formatter '" << Code
1216         << "' for machine instr: " << *MI;
1217    llvm_report_error(Msg.str());
1218  }
1219}
1220
1221/// processDebugLoc - Processes the debug information of each machine
1222/// instruction's DebugLoc.
1223void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1224                                 bool BeforePrintingInsn) {
1225  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1226      || !DW->ShouldEmitDwarfDebug())
1227    return;
1228  DebugLoc DL = MI->getDebugLoc();
1229  if (DL.isUnknown())
1230    return;
1231  DILocation CurDLT = MF->getDILocation(DL);
1232  if (CurDLT.getScope().isNull())
1233    return;
1234
1235  if (!BeforePrintingInsn) {
1236    // After printing instruction
1237    DW->EndScope(MI);
1238  } else if (CurDLT.getNode() != PrevDLT) {
1239    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1240                                      CurDLT.getColumnNumber(),
1241                                      CurDLT.getScope().getNode());
1242    printLabel(L);
1243    O << '\n';
1244    DW->BeginScope(MI, L);
1245    PrevDLT = CurDLT.getNode();
1246  }
1247}
1248
1249
1250/// printInlineAsm - This method formats and prints the specified machine
1251/// instruction that is an inline asm.
1252void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1253  unsigned NumOperands = MI->getNumOperands();
1254
1255  // Count the number of register definitions.
1256  unsigned NumDefs = 0;
1257  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1258       ++NumDefs)
1259    assert(NumDefs != NumOperands-1 && "No asm string?");
1260
1261  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1262
1263  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1264  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1265
1266  O << '\t';
1267
1268  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1269  // These are useful to see where empty asm's wound up.
1270  if (AsmStr[0] == 0) {
1271    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1272    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1273    return;
1274  }
1275
1276  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1277
1278  // The variant of the current asmprinter.
1279  int AsmPrinterVariant = MAI->getAssemblerDialect();
1280
1281  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1282  const char *LastEmitted = AsmStr; // One past the last character emitted.
1283
1284  while (*LastEmitted) {
1285    switch (*LastEmitted) {
1286    default: {
1287      // Not a special case, emit the string section literally.
1288      const char *LiteralEnd = LastEmitted+1;
1289      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1290             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1291        ++LiteralEnd;
1292      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1293        O.write(LastEmitted, LiteralEnd-LastEmitted);
1294      LastEmitted = LiteralEnd;
1295      break;
1296    }
1297    case '\n':
1298      ++LastEmitted;   // Consume newline character.
1299      O << '\n';       // Indent code with newline.
1300      break;
1301    case '$': {
1302      ++LastEmitted;   // Consume '$' character.
1303      bool Done = true;
1304
1305      // Handle escapes.
1306      switch (*LastEmitted) {
1307      default: Done = false; break;
1308      case '$':     // $$ -> $
1309        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1310          O << '$';
1311        ++LastEmitted;  // Consume second '$' character.
1312        break;
1313      case '(':             // $( -> same as GCC's { character.
1314        ++LastEmitted;      // Consume '(' character.
1315        if (CurVariant != -1) {
1316          llvm_report_error("Nested variants found in inline asm string: '"
1317                            + std::string(AsmStr) + "'");
1318        }
1319        CurVariant = 0;     // We're in the first variant now.
1320        break;
1321      case '|':
1322        ++LastEmitted;  // consume '|' character.
1323        if (CurVariant == -1)
1324          O << '|';       // this is gcc's behavior for | outside a variant
1325        else
1326          ++CurVariant;   // We're in the next variant.
1327        break;
1328      case ')':         // $) -> same as GCC's } char.
1329        ++LastEmitted;  // consume ')' character.
1330        if (CurVariant == -1)
1331          O << '}';     // this is gcc's behavior for } outside a variant
1332        else
1333          CurVariant = -1;
1334        break;
1335      }
1336      if (Done) break;
1337
1338      bool HasCurlyBraces = false;
1339      if (*LastEmitted == '{') {     // ${variable}
1340        ++LastEmitted;               // Consume '{' character.
1341        HasCurlyBraces = true;
1342      }
1343
1344      // If we have ${:foo}, then this is not a real operand reference, it is a
1345      // "magic" string reference, just like in .td files.  Arrange to call
1346      // PrintSpecial.
1347      if (HasCurlyBraces && *LastEmitted == ':') {
1348        ++LastEmitted;
1349        const char *StrStart = LastEmitted;
1350        const char *StrEnd = strchr(StrStart, '}');
1351        if (StrEnd == 0) {
1352          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1353                            + std::string(AsmStr) + "'");
1354        }
1355
1356        std::string Val(StrStart, StrEnd);
1357        PrintSpecial(MI, Val.c_str());
1358        LastEmitted = StrEnd+1;
1359        break;
1360      }
1361
1362      const char *IDStart = LastEmitted;
1363      char *IDEnd;
1364      errno = 0;
1365      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1366      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1367        llvm_report_error("Bad $ operand number in inline asm string: '"
1368                          + std::string(AsmStr) + "'");
1369      }
1370      LastEmitted = IDEnd;
1371
1372      char Modifier[2] = { 0, 0 };
1373
1374      if (HasCurlyBraces) {
1375        // If we have curly braces, check for a modifier character.  This
1376        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1377        if (*LastEmitted == ':') {
1378          ++LastEmitted;    // Consume ':' character.
1379          if (*LastEmitted == 0) {
1380            llvm_report_error("Bad ${:} expression in inline asm string: '"
1381                              + std::string(AsmStr) + "'");
1382          }
1383
1384          Modifier[0] = *LastEmitted;
1385          ++LastEmitted;    // Consume modifier character.
1386        }
1387
1388        if (*LastEmitted != '}') {
1389          llvm_report_error("Bad ${} expression in inline asm string: '"
1390                            + std::string(AsmStr) + "'");
1391        }
1392        ++LastEmitted;    // Consume '}' character.
1393      }
1394
1395      if ((unsigned)Val >= NumOperands-1) {
1396        llvm_report_error("Invalid $ operand number in inline asm string: '"
1397                          + std::string(AsmStr) + "'");
1398      }
1399
1400      // Okay, we finally have a value number.  Ask the target to print this
1401      // operand!
1402      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1403        unsigned OpNo = 1;
1404
1405        bool Error = false;
1406
1407        // Scan to find the machine operand number for the operand.
1408        for (; Val; --Val) {
1409          if (OpNo >= MI->getNumOperands()) break;
1410          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1411          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1412        }
1413
1414        if (OpNo >= MI->getNumOperands()) {
1415          Error = true;
1416        } else {
1417          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1418          ++OpNo;  // Skip over the ID number.
1419
1420          if (Modifier[0] == 'l')  // labels are target independent
1421            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1422          else {
1423            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1424            if ((OpFlags & 7) == 4) {
1425              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1426                                                Modifier[0] ? Modifier : 0);
1427            } else {
1428              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1429                                          Modifier[0] ? Modifier : 0);
1430            }
1431          }
1432        }
1433        if (Error) {
1434          std::string msg;
1435          raw_string_ostream Msg(msg);
1436          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1437          MI->print(Msg);
1438          llvm_report_error(Msg.str());
1439        }
1440      }
1441      break;
1442    }
1443    }
1444  }
1445  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1446}
1447
1448/// printImplicitDef - This method prints the specified machine instruction
1449/// that is an implicit def.
1450void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1451  if (!VerboseAsm) return;
1452  O.PadToColumn(MAI->getCommentColumn());
1453  O << MAI->getCommentString() << " implicit-def: "
1454    << TRI->getName(MI->getOperand(0).getReg()) << '\n';
1455}
1456
1457void AsmPrinter::printKill(const MachineInstr *MI) const {
1458  if (!VerboseAsm) return;
1459  O.PadToColumn(MAI->getCommentColumn());
1460  O << MAI->getCommentString() << " kill:";
1461  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1462    const MachineOperand &op = MI->getOperand(n);
1463    assert(op.isReg() && "KILL instruction must have only register operands");
1464    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1465  }
1466  O << '\n';
1467}
1468
1469/// printLabel - This method prints a local label used by debug and
1470/// exception handling tables.
1471void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1472  printLabel(MI->getOperand(0).getImm());
1473  O << '\n';
1474}
1475
1476void AsmPrinter::printLabel(unsigned Id) const {
1477  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1478}
1479
1480/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1481/// instruction, using the specified assembler variant.  Targets should
1482/// override this to format as appropriate.
1483bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1484                                 unsigned AsmVariant, const char *ExtraCode) {
1485  // Target doesn't support this yet!
1486  return true;
1487}
1488
1489bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1490                                       unsigned AsmVariant,
1491                                       const char *ExtraCode) {
1492  // Target doesn't support this yet!
1493  return true;
1494}
1495
1496MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1497  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock());
1498}
1499
1500MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1501                                            const BasicBlock *BB) const {
1502  assert(BB->hasName() &&
1503         "Address of anonymous basic block not supported yet!");
1504
1505  // This code must use the function name itself, and not the function number,
1506  // since it must be possible to generate the label name from within other
1507  // functions.
1508  SmallString<60> FnName;
1509  Mang->getNameWithPrefix(FnName, F, false);
1510
1511  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1512  SmallString<60> NameResult;
1513  Mang->getNameWithPrefix(NameResult,
1514                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1515                          "_" + FnName.str() + "_" + BB->getName(),
1516                          Mangler::Private);
1517
1518  return OutContext.GetOrCreateSymbol(NameResult.str());
1519}
1520
1521/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1522MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1523  SmallString<60> Name;
1524  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1525    << getFunctionNumber() << '_' << CPID;
1526  return OutContext.GetOrCreateSymbol(Name.str());
1527}
1528
1529/// GetJTISymbol - Return the symbol for the specified jump table entry.
1530MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1531  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1532}
1533
1534/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1535/// FIXME: privatize to AsmPrinter.
1536MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1537  SmallString<60> Name;
1538  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1539    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1540  return OutContext.GetOrCreateSymbol(Name.str());
1541}
1542
1543/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1544/// value.
1545MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1546  SmallString<60> NameStr;
1547  Mang->getNameWithPrefix(NameStr, GV, false);
1548  return OutContext.GetOrCreateSymbol(NameStr.str());
1549}
1550
1551/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1552/// global value name as its base, with the specified suffix, and where the
1553/// symbol is forced to have private linkage if ForcePrivate is true.
1554MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1555                                                   StringRef Suffix,
1556                                                   bool ForcePrivate) const {
1557  SmallString<60> NameStr;
1558  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1559  NameStr.append(Suffix.begin(), Suffix.end());
1560  return OutContext.GetOrCreateSymbol(NameStr.str());
1561}
1562
1563/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1564/// ExternalSymbol.
1565MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1566  SmallString<60> NameStr;
1567  Mang->getNameWithPrefix(NameStr, Sym);
1568  return OutContext.GetOrCreateSymbol(NameStr.str());
1569}
1570
1571
1572
1573/// PrintParentLoopComment - Print comments about parent loops of this one.
1574static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1575                                   unsigned FunctionNumber) {
1576  if (Loop == 0) return;
1577  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1578  OS.indent(Loop->getLoopDepth()*2)
1579    << "Parent Loop BB" << FunctionNumber << "_"
1580    << Loop->getHeader()->getNumber()
1581    << " Depth=" << Loop->getLoopDepth() << '\n';
1582}
1583
1584
1585/// PrintChildLoopComment - Print comments about child loops within
1586/// the loop for this basic block, with nesting.
1587static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1588                                  unsigned FunctionNumber) {
1589  // Add child loop information
1590  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1591    OS.indent((*CL)->getLoopDepth()*2)
1592      << "Child Loop BB" << FunctionNumber << "_"
1593      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1594      << '\n';
1595    PrintChildLoopComment(OS, *CL, FunctionNumber);
1596  }
1597}
1598
1599/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1600static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1601                                        const MachineLoopInfo *LI,
1602                                        const AsmPrinter &AP) {
1603  // Add loop depth information
1604  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1605  if (Loop == 0) return;
1606
1607  MachineBasicBlock *Header = Loop->getHeader();
1608  assert(Header && "No header for loop");
1609
1610  // If this block is not a loop header, just print out what is the loop header
1611  // and return.
1612  if (Header != &MBB) {
1613    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1614                              Twine(AP.getFunctionNumber())+"_" +
1615                              Twine(Loop->getHeader()->getNumber())+
1616                              " Depth="+Twine(Loop->getLoopDepth()));
1617    return;
1618  }
1619
1620  // Otherwise, it is a loop header.  Print out information about child and
1621  // parent loops.
1622  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1623
1624  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1625
1626  OS << "=>";
1627  OS.indent(Loop->getLoopDepth()*2-2);
1628
1629  OS << "This ";
1630  if (Loop->empty())
1631    OS << "Inner ";
1632  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1633
1634  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1635}
1636
1637
1638/// EmitBasicBlockStart - This method prints the label for the specified
1639/// MachineBasicBlock, an alignment (if present) and a comment describing
1640/// it if appropriate.
1641void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1642  // Emit an alignment directive for this block, if needed.
1643  if (unsigned Align = MBB->getAlignment())
1644    EmitAlignment(Log2_32(Align));
1645
1646  // If the block has its address taken, emit a special label to satisfy
1647  // references to the block. This is done so that we don't need to
1648  // remember the number of this label, and so that we can make
1649  // forward references to labels without knowing what their numbers
1650  // will be.
1651  if (MBB->hasAddressTaken()) {
1652    const BasicBlock *BB = MBB->getBasicBlock();
1653    if (VerboseAsm)
1654      OutStreamer.AddComment("Address Taken");
1655    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1656  }
1657
1658  // Print the main label for the block.
1659  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1660    if (VerboseAsm) {
1661      // NOTE: Want this comment at start of line.
1662      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1663      if (const BasicBlock *BB = MBB->getBasicBlock())
1664        if (BB->hasName())
1665          OutStreamer.AddComment("%" + BB->getName());
1666
1667      PrintBasicBlockLoopComments(*MBB, LI, *this);
1668      OutStreamer.AddBlankLine();
1669    }
1670  } else {
1671    if (VerboseAsm) {
1672      if (const BasicBlock *BB = MBB->getBasicBlock())
1673        if (BB->hasName())
1674          OutStreamer.AddComment("%" + BB->getName());
1675      PrintBasicBlockLoopComments(*MBB, LI, *this);
1676    }
1677
1678    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1679  }
1680}
1681
1682void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1683  MCSymbolAttr Attr = MCSA_Invalid;
1684
1685  switch (Visibility) {
1686  default: break;
1687  case GlobalValue::HiddenVisibility:
1688    Attr = MAI->getHiddenVisibilityAttr();
1689    break;
1690  case GlobalValue::ProtectedVisibility:
1691    Attr = MAI->getProtectedVisibilityAttr();
1692    break;
1693  }
1694
1695  if (Attr != MCSA_Invalid)
1696    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1697}
1698
1699void AsmPrinter::printOffset(int64_t Offset) const {
1700  if (Offset > 0)
1701    O << '+' << Offset;
1702  else if (Offset < 0)
1703    O << Offset;
1704}
1705
1706GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1707  if (!S->usesMetadata())
1708    return 0;
1709
1710  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1711  if (GCPI != GCMetadataPrinters.end())
1712    return GCPI->second;
1713
1714  const char *Name = S->getName().c_str();
1715
1716  for (GCMetadataPrinterRegistry::iterator
1717         I = GCMetadataPrinterRegistry::begin(),
1718         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1719    if (strcmp(Name, I->getName()) == 0) {
1720      GCMetadataPrinter *GMP = I->instantiate();
1721      GMP->S = S;
1722      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1723      return GMP;
1724    }
1725
1726  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1727  return 0;
1728}
1729
1730/// EmitComments - Pretty-print comments for instructions
1731void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1732  if (!VerboseAsm)
1733    return;
1734
1735  if (!MI.getDebugLoc().isUnknown()) {
1736    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1737
1738    // Print source line info.
1739    O.PadToColumn(MAI->getCommentColumn());
1740    O << MAI->getCommentString() << ' ';
1741    DIScope Scope = DLT.getScope();
1742    // Omit the directory, because it's likely to be long and uninteresting.
1743    if (!Scope.isNull())
1744      O << Scope.getFilename();
1745    else
1746      O << "<unknown>";
1747    O << ':' << DLT.getLineNumber();
1748    if (DLT.getColumnNumber() != 0)
1749      O << ':' << DLT.getColumnNumber();
1750    O << '\n';
1751  }
1752
1753  // Check for spills and reloads
1754  int FI;
1755
1756  const MachineFrameInfo *FrameInfo =
1757    MI.getParent()->getParent()->getFrameInfo();
1758
1759  // We assume a single instruction only has a spill or reload, not
1760  // both.
1761  const MachineMemOperand *MMO;
1762  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1763    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1764      MMO = *MI.memoperands_begin();
1765      O.PadToColumn(MAI->getCommentColumn());
1766      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload\n";
1767    }
1768  }
1769  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1770    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1771      O.PadToColumn(MAI->getCommentColumn());
1772      O << MAI->getCommentString() << ' '
1773        << MMO->getSize() << "-byte Folded Reload\n";
1774    }
1775  }
1776  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1777    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1778      MMO = *MI.memoperands_begin();
1779      O.PadToColumn(MAI->getCommentColumn());
1780      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill\n";
1781    }
1782  }
1783  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1784    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1785      O.PadToColumn(MAI->getCommentColumn());
1786      O << MAI->getCommentString() << ' '
1787        << MMO->getSize() << "-byte Folded Spill\n";
1788    }
1789  }
1790
1791  // Check for spill-induced copies
1792  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1793  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1794                                      SrcSubIdx, DstSubIdx)) {
1795    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1796      O.PadToColumn(MAI->getCommentColumn());
1797      O << MAI->getCommentString() << " Reload Reuse\n";
1798    }
1799  }
1800}
1801
1802