AsmPrinter.cpp revision 1b2eb0e8a6aaf034675b17be6d853cb1c666200f 
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AsmPrinter class.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "asm-printer"
15#include "llvm/CodeGen/AsmPrinter.h"
16#include "llvm/Assembly/Writer.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constants.h"
19#include "llvm/Module.h"
20#include "llvm/CodeGen/DwarfWriter.h"
21#include "llvm/CodeGen/GCMetadataPrinter.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineFunction.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineLoopInfo.h"
27#include "llvm/CodeGen/MachineModuleInfo.h"
28#include "llvm/Analysis/ConstantFolding.h"
29#include "llvm/Analysis/DebugInfo.h"
30#include "llvm/MC/MCContext.h"
31#include "llvm/MC/MCExpr.h"
32#include "llvm/MC/MCInst.h"
33#include "llvm/MC/MCSection.h"
34#include "llvm/MC/MCStreamer.h"
35#include "llvm/MC/MCSymbol.h"
36#include "llvm/MC/MCAsmInfo.h"
37#include "llvm/Target/Mangler.h"
38#include "llvm/Target/TargetData.h"
39#include "llvm/Target/TargetInstrInfo.h"
40#include "llvm/Target/TargetLowering.h"
41#include "llvm/Target/TargetLoweringObjectFile.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/Target/TargetRegisterInfo.h"
44#include "llvm/ADT/SmallPtrSet.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/ADT/Statistic.h"
47#include "llvm/Support/CommandLine.h"
48#include "llvm/Support/Debug.h"
49#include "llvm/Support/ErrorHandling.h"
50#include "llvm/Support/Format.h"
51#include "llvm/Support/FormattedStream.h"
52#include <cerrno>
53using namespace llvm;
54
55STATISTIC(EmittedInsts, "Number of machine instrs printed");
56
57char AsmPrinter::ID = 0;
58
59AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
60                       MCStreamer &Streamer)
61  : MachineFunctionPass(&ID), O(o),
62    TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()),
63    OutContext(Streamer.getContext()),
64    OutStreamer(Streamer),
65    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0), PrevDLT(NULL) {
66  DW = 0; MMI = 0;
67  VerboseAsm = Streamer.isVerboseAsm();
68}
69
70AsmPrinter::~AsmPrinter() {
71  for (gcp_iterator I = GCMetadataPrinters.begin(),
72                    E = GCMetadataPrinters.end(); I != E; ++I)
73    delete I->second;
74
75  delete &OutStreamer;
76}
77
78/// getFunctionNumber - Return a unique ID for the current function.
79///
80unsigned AsmPrinter::getFunctionNumber() const {
81  return MF->getFunctionNumber();
82}
83
84TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
85  return TM.getTargetLowering()->getObjFileLowering();
86}
87
88/// getCurrentSection() - Return the current section we are emitting to.
89const MCSection *AsmPrinter::getCurrentSection() const {
90  return OutStreamer.getCurrentSection();
91}
92
93
94void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
95  AU.setPreservesAll();
96  MachineFunctionPass::getAnalysisUsage(AU);
97  AU.addRequired<MachineModuleInfo>();
98  AU.addRequired<GCModuleInfo>();
99  if (VerboseAsm)
100    AU.addRequired<MachineLoopInfo>();
101}
102
103bool AsmPrinter::doInitialization(Module &M) {
104  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
105  MMI->AnalyzeModule(M);
106
107  // Initialize TargetLoweringObjectFile.
108  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
109    .Initialize(OutContext, TM);
110
111  Mang = new Mangler(OutContext, *TM.getTargetData());
112
113  // Allow the target to emit any magic that it wants at the start of the file.
114  EmitStartOfAsmFile(M);
115
116  // Very minimal debug info. It is ignored if we emit actual debug info. If we
117  // don't, this at least helps the user find where a global came from.
118  if (MAI->hasSingleParameterDotFile()) {
119    // .file "foo.c"
120    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
121  }
122
123  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
124  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
125  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
126    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
127      MP->beginAssembly(O, *this, *MAI);
128
129  if (!M.getModuleInlineAsm().empty())
130    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
131      << M.getModuleInlineAsm()
132      << '\n' << MAI->getCommentString()
133      << " End of file scope inline assembly\n";
134
135  DW = getAnalysisIfAvailable<DwarfWriter>();
136  if (DW)
137    DW->BeginModule(&M, MMI, O, this, MAI);
138
139  return false;
140}
141
142void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
143  switch ((GlobalValue::LinkageTypes)Linkage) {
144  case GlobalValue::CommonLinkage:
145  case GlobalValue::LinkOnceAnyLinkage:
146  case GlobalValue::LinkOnceODRLinkage:
147  case GlobalValue::WeakAnyLinkage:
148  case GlobalValue::WeakODRLinkage:
149  case GlobalValue::LinkerPrivateLinkage:
150    if (MAI->getWeakDefDirective() != 0) {
151      // .globl _foo
152      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
153      // .weak_definition _foo
154      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
155    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
156      // .globl _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
158      // FIXME: linkonce should be a section attribute, handled by COFF Section
159      // assignment.
160      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
161      // .linkonce discard
162      // FIXME: It would be nice to use .linkonce samesize for non-common
163      // globals.
164      O << LinkOnce;
165    } else {
166      // .weak _foo
167      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
168    }
169    break;
170  case GlobalValue::DLLExportLinkage:
171  case GlobalValue::AppendingLinkage:
172    // FIXME: appending linkage variables should go into a section of
173    // their name or something.  For now, just emit them as external.
174  case GlobalValue::ExternalLinkage:
175    // If external or appending, declare as a global symbol.
176    // .globl _foo
177    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
178    break;
179  case GlobalValue::PrivateLinkage:
180  case GlobalValue::InternalLinkage:
181    break;
182  default:
183    llvm_unreachable("Unknown linkage type!");
184  }
185}
186
187
188/// EmitGlobalVariable - Emit the specified global variable to the .s file.
189void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
190  if (!GV->hasInitializer())   // External globals require no code.
191    return;
192
193  // Check to see if this is a special global used by LLVM, if so, emit it.
194  if (EmitSpecialLLVMGlobal(GV))
195    return;
196
197  MCSymbol *GVSym = Mang->getSymbol(GV);
198  EmitVisibility(GVSym, GV->getVisibility());
199
200  if (MAI->hasDotTypeDotSizeDirective())
201    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
202
203  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
204
205  const TargetData *TD = TM.getTargetData();
206  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
207  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
208
209  // Handle common and BSS local symbols (.lcomm).
210  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
211    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
212
213    if (VerboseAsm) {
214      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
215                     /*PrintType=*/false, GV->getParent());
216      OutStreamer.GetCommentOS() << '\n';
217    }
218
219    // Handle common symbols.
220    if (GVKind.isCommon()) {
221      // .comm _foo, 42, 4
222      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
223      return;
224    }
225
226    // Handle local BSS symbols.
227    if (MAI->hasMachoZeroFillDirective()) {
228      const MCSection *TheSection =
229        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
230      // .zerofill __DATA, __bss, _foo, 400, 5
231      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
232      return;
233    }
234
235    if (MAI->hasLCOMMDirective()) {
236      // .lcomm _foo, 42
237      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
238      return;
239    }
240
241    // .local _foo
242    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
243    // .comm _foo, 42, 4
244    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
245    return;
246  }
247
248  const MCSection *TheSection =
249    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
250
251  // Handle the zerofill directive on darwin, which is a special form of BSS
252  // emission.
253  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
254    // .globl _foo
255    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
256    // .zerofill __DATA, __common, _foo, 400, 5
257    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
258    return;
259  }
260
261  OutStreamer.SwitchSection(TheSection);
262
263  EmitLinkage(GV->getLinkage(), GVSym);
264  EmitAlignment(AlignLog, GV);
265
266  if (VerboseAsm) {
267    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
268                   /*PrintType=*/false, GV->getParent());
269    OutStreamer.GetCommentOS() << '\n';
270  }
271  OutStreamer.EmitLabel(GVSym);
272
273  EmitGlobalConstant(GV->getInitializer());
274
275  if (MAI->hasDotTypeDotSizeDirective())
276    // .size foo, 42
277    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
278
279  OutStreamer.AddBlankLine();
280}
281
282/// EmitFunctionHeader - This method emits the header for the current
283/// function.
284void AsmPrinter::EmitFunctionHeader() {
285  // Print out constants referenced by the function
286  EmitConstantPool();
287
288  // Print the 'header' of function.
289  const Function *F = MF->getFunction();
290
291  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
292  EmitVisibility(CurrentFnSym, F->getVisibility());
293
294  EmitLinkage(F->getLinkage(), CurrentFnSym);
295  EmitAlignment(MF->getAlignment(), F);
296
297  if (MAI->hasDotTypeDotSizeDirective())
298    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
299
300  if (VerboseAsm) {
301    WriteAsOperand(OutStreamer.GetCommentOS(), F,
302                   /*PrintType=*/false, F->getParent());
303    OutStreamer.GetCommentOS() << '\n';
304  }
305
306  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
307  // do their wild and crazy things as required.
308  EmitFunctionEntryLabel();
309
310  // Add some workaround for linkonce linkage on Cygwin\MinGW.
311  if (MAI->getLinkOnceDirective() != 0 &&
312      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
313    // FIXME: What is this?
314    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
315
316  // Emit pre-function debug and/or EH information.
317  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
318    DW->BeginFunction(MF);
319}
320
321/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
322/// function.  This can be overridden by targets as required to do custom stuff.
323void AsmPrinter::EmitFunctionEntryLabel() {
324  OutStreamer.EmitLabel(CurrentFnSym);
325}
326
327
328/// EmitComments - Pretty-print comments for instructions.
329static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
330  const MachineFunction *MF = MI.getParent()->getParent();
331  const TargetMachine &TM = MF->getTarget();
332
333  if (!MI.getDebugLoc().isUnknown()) {
334    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
335
336    // Print source line info.
337    DIScope Scope = DLT.getScope();
338    // Omit the directory, because it's likely to be long and uninteresting.
339    if (Scope.Verify())
340      CommentOS << Scope.getFilename();
341    else
342      CommentOS << "<unknown>";
343    CommentOS << ':' << DLT.getLineNumber();
344    if (DLT.getColumnNumber() != 0)
345      CommentOS << ':' << DLT.getColumnNumber();
346    CommentOS << '\n';
347  }
348
349  // Check for spills and reloads
350  int FI;
351
352  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
353
354  // We assume a single instruction only has a spill or reload, not
355  // both.
356  const MachineMemOperand *MMO;
357  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
358    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
359      MMO = *MI.memoperands_begin();
360      CommentOS << MMO->getSize() << "-byte Reload\n";
361    }
362  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
363    if (FrameInfo->isSpillSlotObjectIndex(FI))
364      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
365  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
366    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
367      MMO = *MI.memoperands_begin();
368      CommentOS << MMO->getSize() << "-byte Spill\n";
369    }
370  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
371    if (FrameInfo->isSpillSlotObjectIndex(FI))
372      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
373  }
374
375  // Check for spill-induced copies
376  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
377  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
378                                     SrcSubIdx, DstSubIdx)) {
379    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
380      CommentOS << " Reload Reuse\n";
381  }
382}
383
384
385
386/// EmitFunctionBody - This method emits the body and trailer for a
387/// function.
388void AsmPrinter::EmitFunctionBody() {
389  // Emit target-specific gunk before the function body.
390  EmitFunctionBodyStart();
391
392  // Print out code for the function.
393  bool HasAnyRealCode = false;
394  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
395       I != E; ++I) {
396    // Print a label for the basic block.
397    EmitBasicBlockStart(I);
398    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
399         II != IE; ++II) {
400      // Print the assembly for the instruction.
401      if (!II->isLabel())
402        HasAnyRealCode = true;
403
404      ++EmittedInsts;
405
406      // FIXME: Clean up processDebugLoc.
407      processDebugLoc(II, true);
408
409      if (VerboseAsm)
410        EmitComments(*II, OutStreamer.GetCommentOS());
411
412      switch (II->getOpcode()) {
413      case TargetOpcode::DBG_LABEL:
414      case TargetOpcode::EH_LABEL:
415      case TargetOpcode::GC_LABEL:
416        printLabelInst(II);
417        break;
418      case TargetOpcode::INLINEASM:
419        printInlineAsm(II);
420        break;
421      case TargetOpcode::IMPLICIT_DEF:
422        printImplicitDef(II);
423        break;
424      case TargetOpcode::KILL:
425        printKill(II);
426        break;
427      default:
428        EmitInstruction(II);
429        break;
430      }
431
432      // FIXME: Clean up processDebugLoc.
433      processDebugLoc(II, false);
434    }
435  }
436
437  // If the function is empty and the object file uses .subsections_via_symbols,
438  // then we need to emit *something* to the function body to prevent the
439  // labels from collapsing together.  Just emit a 0 byte.
440  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
441    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
442
443  // Emit target-specific gunk after the function body.
444  EmitFunctionBodyEnd();
445
446  if (MAI->hasDotTypeDotSizeDirective())
447    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
448
449  // Emit post-function debug information.
450  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
451    DW->EndFunction(MF);
452
453  // Print out jump tables referenced by the function.
454  EmitJumpTableInfo();
455
456  OutStreamer.AddBlankLine();
457}
458
459
460bool AsmPrinter::doFinalization(Module &M) {
461  // Emit global variables.
462  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
463       I != E; ++I)
464    EmitGlobalVariable(I);
465
466  // Emit final debug information.
467  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
468    DW->EndModule();
469
470  // If the target wants to know about weak references, print them all.
471  if (MAI->getWeakRefDirective()) {
472    // FIXME: This is not lazy, it would be nice to only print weak references
473    // to stuff that is actually used.  Note that doing so would require targets
474    // to notice uses in operands (due to constant exprs etc).  This should
475    // happen with the MC stuff eventually.
476
477    // Print out module-level global variables here.
478    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
479         I != E; ++I) {
480      if (!I->hasExternalWeakLinkage()) continue;
481      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
482    }
483
484    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
485      if (!I->hasExternalWeakLinkage()) continue;
486      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
487    }
488  }
489
490  if (MAI->hasSetDirective()) {
491    OutStreamer.AddBlankLine();
492    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
493         I != E; ++I) {
494      MCSymbol *Name = Mang->getSymbol(I);
495
496      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
497      MCSymbol *Target = Mang->getSymbol(GV);
498
499      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
500        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
501      else if (I->hasWeakLinkage())
502        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
503      else
504        assert(I->hasLocalLinkage() && "Invalid alias linkage");
505
506      EmitVisibility(Name, I->getVisibility());
507
508      // Emit the directives as assignments aka .set:
509      OutStreamer.EmitAssignment(Name,
510                                 MCSymbolRefExpr::Create(Target, OutContext));
511    }
512  }
513
514  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
515  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
516  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
517    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
518      MP->finishAssembly(O, *this, *MAI);
519
520  // If we don't have any trampolines, then we don't require stack memory
521  // to be executable. Some targets have a directive to declare this.
522  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
523  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
524    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
525      OutStreamer.SwitchSection(S);
526
527  // Allow the target to emit any magic that it wants at the end of the file,
528  // after everything else has gone out.
529  EmitEndOfAsmFile(M);
530
531  delete Mang; Mang = 0;
532  DW = 0; MMI = 0;
533
534  OutStreamer.Finish();
535  return false;
536}
537
538void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
539  this->MF = &MF;
540  // Get the function symbol.
541  CurrentFnSym = Mang->getSymbol(MF.getFunction());
542
543  if (VerboseAsm)
544    LI = &getAnalysis<MachineLoopInfo>();
545}
546
547namespace {
548  // SectionCPs - Keep track the alignment, constpool entries per Section.
549  struct SectionCPs {
550    const MCSection *S;
551    unsigned Alignment;
552    SmallVector<unsigned, 4> CPEs;
553    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
554  };
555}
556
557/// EmitConstantPool - Print to the current output stream assembly
558/// representations of the constants in the constant pool MCP. This is
559/// used to print out constants which have been "spilled to memory" by
560/// the code generator.
561///
562void AsmPrinter::EmitConstantPool() {
563  const MachineConstantPool *MCP = MF->getConstantPool();
564  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
565  if (CP.empty()) return;
566
567  // Calculate sections for constant pool entries. We collect entries to go into
568  // the same section together to reduce amount of section switch statements.
569  SmallVector<SectionCPs, 4> CPSections;
570  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
571    const MachineConstantPoolEntry &CPE = CP[i];
572    unsigned Align = CPE.getAlignment();
573
574    SectionKind Kind;
575    switch (CPE.getRelocationInfo()) {
576    default: llvm_unreachable("Unknown section kind");
577    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
578    case 1:
579      Kind = SectionKind::getReadOnlyWithRelLocal();
580      break;
581    case 0:
582    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
583    case 4:  Kind = SectionKind::getMergeableConst4(); break;
584    case 8:  Kind = SectionKind::getMergeableConst8(); break;
585    case 16: Kind = SectionKind::getMergeableConst16();break;
586    default: Kind = SectionKind::getMergeableConst(); break;
587    }
588    }
589
590    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
591
592    // The number of sections are small, just do a linear search from the
593    // last section to the first.
594    bool Found = false;
595    unsigned SecIdx = CPSections.size();
596    while (SecIdx != 0) {
597      if (CPSections[--SecIdx].S == S) {
598        Found = true;
599        break;
600      }
601    }
602    if (!Found) {
603      SecIdx = CPSections.size();
604      CPSections.push_back(SectionCPs(S, Align));
605    }
606
607    if (Align > CPSections[SecIdx].Alignment)
608      CPSections[SecIdx].Alignment = Align;
609    CPSections[SecIdx].CPEs.push_back(i);
610  }
611
612  // Now print stuff into the calculated sections.
613  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
614    OutStreamer.SwitchSection(CPSections[i].S);
615    EmitAlignment(Log2_32(CPSections[i].Alignment));
616
617    unsigned Offset = 0;
618    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
619      unsigned CPI = CPSections[i].CPEs[j];
620      MachineConstantPoolEntry CPE = CP[CPI];
621
622      // Emit inter-object padding for alignment.
623      unsigned AlignMask = CPE.getAlignment() - 1;
624      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
625      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
626
627      const Type *Ty = CPE.getType();
628      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
629
630      // Emit the label with a comment on it.
631      if (VerboseAsm) {
632        OutStreamer.GetCommentOS() << "constant pool ";
633        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
634                          MF->getFunction()->getParent());
635        OutStreamer.GetCommentOS() << '\n';
636      }
637      OutStreamer.EmitLabel(GetCPISymbol(CPI));
638
639      if (CPE.isMachineConstantPoolEntry())
640        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
641      else
642        EmitGlobalConstant(CPE.Val.ConstVal);
643    }
644  }
645}
646
647/// EmitJumpTableInfo - Print assembly representations of the jump tables used
648/// by the current function to the current output stream.
649///
650void AsmPrinter::EmitJumpTableInfo() {
651  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
652  if (MJTI == 0) return;
653  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
654  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
655  if (JT.empty()) return;
656
657  // Pick the directive to use to print the jump table entries, and switch to
658  // the appropriate section.
659  const Function *F = MF->getFunction();
660  bool JTInDiffSection = false;
661  if (// In PIC mode, we need to emit the jump table to the same section as the
662      // function body itself, otherwise the label differences won't make sense.
663      // FIXME: Need a better predicate for this: what about custom entries?
664      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
665      // We should also do if the section name is NULL or function is declared
666      // in discardable section
667      // FIXME: this isn't the right predicate, should be based on the MCSection
668      // for the function.
669      F->isWeakForLinker()) {
670    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
671  } else {
672    // Otherwise, drop it in the readonly section.
673    const MCSection *ReadOnlySection =
674      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
675    OutStreamer.SwitchSection(ReadOnlySection);
676    JTInDiffSection = true;
677  }
678
679  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
680
681  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
682    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
683
684    // If this jump table was deleted, ignore it.
685    if (JTBBs.empty()) continue;
686
687    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
688    // .set directive for each unique entry.  This reduces the number of
689    // relocations the assembler will generate for the jump table.
690    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
691        MAI->hasSetDirective()) {
692      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
693      const TargetLowering *TLI = TM.getTargetLowering();
694      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
695      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
696        const MachineBasicBlock *MBB = JTBBs[ii];
697        if (!EmittedSets.insert(MBB)) continue;
698
699        // .set LJTSet, LBB32-base
700        const MCExpr *LHS =
701          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
702        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
703                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
704      }
705    }
706
707    // On some targets (e.g. Darwin) we want to emit two consequtive labels
708    // before each jump table.  The first label is never referenced, but tells
709    // the assembler and linker the extents of the jump table object.  The
710    // second label is actually referenced by the code.
711    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
712      // FIXME: This doesn't have to have any specific name, just any randomly
713      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
714      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
715
716    OutStreamer.EmitLabel(GetJTISymbol(JTI));
717
718    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
719      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
720  }
721}
722
723/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
724/// current stream.
725void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
726                                    const MachineBasicBlock *MBB,
727                                    unsigned UID) const {
728  const MCExpr *Value = 0;
729  switch (MJTI->getEntryKind()) {
730  case MachineJumpTableInfo::EK_Inline:
731    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
732  case MachineJumpTableInfo::EK_Custom32:
733    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
734                                                              OutContext);
735    break;
736  case MachineJumpTableInfo::EK_BlockAddress:
737    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
738    //     .word LBB123
739    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
740    break;
741  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
742    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
743    // with a relocation as gp-relative, e.g.:
744    //     .gprel32 LBB123
745    MCSymbol *MBBSym = MBB->getSymbol();
746    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
747    return;
748  }
749
750  case MachineJumpTableInfo::EK_LabelDifference32: {
751    // EK_LabelDifference32 - Each entry is the address of the block minus
752    // the address of the jump table.  This is used for PIC jump tables where
753    // gprel32 is not supported.  e.g.:
754    //      .word LBB123 - LJTI1_2
755    // If the .set directive is supported, this is emitted as:
756    //      .set L4_5_set_123, LBB123 - LJTI1_2
757    //      .word L4_5_set_123
758
759    // If we have emitted set directives for the jump table entries, print
760    // them rather than the entries themselves.  If we're emitting PIC, then
761    // emit the table entries as differences between two text section labels.
762    if (MAI->hasSetDirective()) {
763      // If we used .set, reference the .set's symbol.
764      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
765                                      OutContext);
766      break;
767    }
768    // Otherwise, use the difference as the jump table entry.
769    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
770    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
771    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
772    break;
773  }
774  }
775
776  assert(Value && "Unknown entry kind!");
777
778  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
779  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
780}
781
782
783/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
784/// special global used by LLVM.  If so, emit it and return true, otherwise
785/// do nothing and return false.
786bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
787  if (GV->getName() == "llvm.used") {
788    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
789      EmitLLVMUsedList(GV->getInitializer());
790    return true;
791  }
792
793  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
794  if (GV->getSection() == "llvm.metadata" ||
795      GV->hasAvailableExternallyLinkage())
796    return true;
797
798  if (!GV->hasAppendingLinkage()) return false;
799
800  assert(GV->hasInitializer() && "Not a special LLVM global!");
801
802  const TargetData *TD = TM.getTargetData();
803  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
804  if (GV->getName() == "llvm.global_ctors") {
805    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
806    EmitAlignment(Align, 0);
807    EmitXXStructorList(GV->getInitializer());
808
809    if (TM.getRelocationModel() == Reloc::Static &&
810        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
811      StringRef Sym(".constructors_used");
812      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
813                                      MCSA_Reference);
814    }
815    return true;
816  }
817
818  if (GV->getName() == "llvm.global_dtors") {
819    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
820    EmitAlignment(Align, 0);
821    EmitXXStructorList(GV->getInitializer());
822
823    if (TM.getRelocationModel() == Reloc::Static &&
824        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
825      StringRef Sym(".destructors_used");
826      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
827                                      MCSA_Reference);
828    }
829    return true;
830  }
831
832  return false;
833}
834
835/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
836/// global in the specified llvm.used list for which emitUsedDirectiveFor
837/// is true, as being used with this directive.
838void AsmPrinter::EmitLLVMUsedList(Constant *List) {
839  // Should be an array of 'i8*'.
840  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
841  if (InitList == 0) return;
842
843  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
844    const GlobalValue *GV =
845      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
846    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
847      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
848  }
849}
850
851/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
852/// function pointers, ignoring the init priority.
853void AsmPrinter::EmitXXStructorList(Constant *List) {
854  // Should be an array of '{ int, void ()* }' structs.  The first value is the
855  // init priority, which we ignore.
856  if (!isa<ConstantArray>(List)) return;
857  ConstantArray *InitList = cast<ConstantArray>(List);
858  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
859    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
860      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
861
862      if (CS->getOperand(1)->isNullValue())
863        return;  // Found a null terminator, exit printing.
864      // Emit the function pointer.
865      EmitGlobalConstant(CS->getOperand(1));
866    }
867}
868
869//===--------------------------------------------------------------------===//
870// Emission and print routines
871//
872
873/// EmitInt8 - Emit a byte directive and value.
874///
875void AsmPrinter::EmitInt8(int Value) const {
876  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
877}
878
879/// EmitInt16 - Emit a short directive and value.
880///
881void AsmPrinter::EmitInt16(int Value) const {
882  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
883}
884
885/// EmitInt32 - Emit a long directive and value.
886///
887void AsmPrinter::EmitInt32(int Value) const {
888  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
889}
890
891/// EmitInt64 - Emit a long long directive and value.
892///
893void AsmPrinter::EmitInt64(uint64_t Value) const {
894  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
895}
896
897/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
898/// in bytes of the directive is specified by Size and Hi/Lo specify the
899/// labels.  This implicitly uses .set if it is available.
900void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
901                                     unsigned Size) const {
902  // Get the Hi-Lo expression.
903  const MCExpr *Diff =
904    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
905                            MCSymbolRefExpr::Create(Lo, OutContext),
906                            OutContext);
907
908  if (!MAI->hasSetDirective()) {
909    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
910    return;
911  }
912
913  // Otherwise, emit with .set (aka assignment).
914  MCSymbol *SetLabel =
915    OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
916                                          "set" + Twine(SetCounter++));
917  OutStreamer.EmitAssignment(SetLabel, Diff);
918  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
919}
920
921
922//===----------------------------------------------------------------------===//
923
924// EmitAlignment - Emit an alignment directive to the specified power of
925// two boundary.  For example, if you pass in 3 here, you will get an 8
926// byte alignment.  If a global value is specified, and if that global has
927// an explicit alignment requested, it will unconditionally override the
928// alignment request.  However, if ForcedAlignBits is specified, this value
929// has final say: the ultimate alignment will be the max of ForcedAlignBits
930// and the alignment computed with NumBits and the global.
931//
932// The algorithm is:
933//     Align = NumBits;
934//     if (GV && GV->hasalignment) Align = GV->getalignment();
935//     Align = std::max(Align, ForcedAlignBits);
936//
937void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
938                               unsigned ForcedAlignBits,
939                               bool UseFillExpr) const {
940  if (GV && GV->getAlignment())
941    NumBits = Log2_32(GV->getAlignment());
942  NumBits = std::max(NumBits, ForcedAlignBits);
943
944  if (NumBits == 0) return;   // No need to emit alignment.
945
946  if (getCurrentSection()->getKind().isText())
947    OutStreamer.EmitCodeAlignment(1 << NumBits);
948  else
949    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
950}
951
952/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
953///
954static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
955  MCContext &Ctx = AP.OutContext;
956
957  if (CV->isNullValue() || isa<UndefValue>(CV))
958    return MCConstantExpr::Create(0, Ctx);
959
960  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
961    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
962
963  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
964    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
965  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
966    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
967
968  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
969  if (CE == 0) {
970    llvm_unreachable("Unknown constant value to lower!");
971    return MCConstantExpr::Create(0, Ctx);
972  }
973
974  switch (CE->getOpcode()) {
975  default:
976    // If the code isn't optimized, there may be outstanding folding
977    // opportunities. Attempt to fold the expression using TargetData as a
978    // last resort before giving up.
979    if (Constant *C =
980          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
981      if (C != CE)
982        return LowerConstant(C, AP);
983#ifndef NDEBUG
984    CE->dump();
985#endif
986    llvm_unreachable("FIXME: Don't support this constant expr");
987  case Instruction::GetElementPtr: {
988    const TargetData &TD = *AP.TM.getTargetData();
989    // Generate a symbolic expression for the byte address
990    const Constant *PtrVal = CE->getOperand(0);
991    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
992    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
993                                         IdxVec.size());
994
995    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
996    if (Offset == 0)
997      return Base;
998
999    // Truncate/sext the offset to the pointer size.
1000    if (TD.getPointerSizeInBits() != 64) {
1001      int SExtAmount = 64-TD.getPointerSizeInBits();
1002      Offset = (Offset << SExtAmount) >> SExtAmount;
1003    }
1004
1005    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1006                                   Ctx);
1007  }
1008
1009  case Instruction::Trunc:
1010    // We emit the value and depend on the assembler to truncate the generated
1011    // expression properly.  This is important for differences between
1012    // blockaddress labels.  Since the two labels are in the same function, it
1013    // is reasonable to treat their delta as a 32-bit value.
1014    // FALL THROUGH.
1015  case Instruction::BitCast:
1016    return LowerConstant(CE->getOperand(0), AP);
1017
1018  case Instruction::IntToPtr: {
1019    const TargetData &TD = *AP.TM.getTargetData();
1020    // Handle casts to pointers by changing them into casts to the appropriate
1021    // integer type.  This promotes constant folding and simplifies this code.
1022    Constant *Op = CE->getOperand(0);
1023    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1024                                      false/*ZExt*/);
1025    return LowerConstant(Op, AP);
1026  }
1027
1028  case Instruction::PtrToInt: {
1029    const TargetData &TD = *AP.TM.getTargetData();
1030    // Support only foldable casts to/from pointers that can be eliminated by
1031    // changing the pointer to the appropriately sized integer type.
1032    Constant *Op = CE->getOperand(0);
1033    const Type *Ty = CE->getType();
1034
1035    const MCExpr *OpExpr = LowerConstant(Op, AP);
1036
1037    // We can emit the pointer value into this slot if the slot is an
1038    // integer slot equal to the size of the pointer.
1039    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1040      return OpExpr;
1041
1042    // Otherwise the pointer is smaller than the resultant integer, mask off
1043    // the high bits so we are sure to get a proper truncation if the input is
1044    // a constant expr.
1045    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1046    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1047    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1048  }
1049
1050  // The MC library also has a right-shift operator, but it isn't consistently
1051  // signed or unsigned between different targets.
1052  case Instruction::Add:
1053  case Instruction::Sub:
1054  case Instruction::Mul:
1055  case Instruction::SDiv:
1056  case Instruction::SRem:
1057  case Instruction::Shl:
1058  case Instruction::And:
1059  case Instruction::Or:
1060  case Instruction::Xor: {
1061    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1062    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1063    switch (CE->getOpcode()) {
1064    default: llvm_unreachable("Unknown binary operator constant cast expr");
1065    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1066    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1067    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1068    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1069    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1070    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1071    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1072    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1073    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1074    }
1075  }
1076  }
1077}
1078
1079static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1080                                    AsmPrinter &AP) {
1081  if (AddrSpace != 0 || !CA->isString()) {
1082    // Not a string.  Print the values in successive locations
1083    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1084      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1085    return;
1086  }
1087
1088  // Otherwise, it can be emitted as .ascii.
1089  SmallVector<char, 128> TmpVec;
1090  TmpVec.reserve(CA->getNumOperands());
1091  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1092    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1093
1094  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1095}
1096
1097static void EmitGlobalConstantVector(const ConstantVector *CV,
1098                                     unsigned AddrSpace, AsmPrinter &AP) {
1099  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1100    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1101}
1102
1103static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1104                                     unsigned AddrSpace, AsmPrinter &AP) {
1105  // Print the fields in successive locations. Pad to align if needed!
1106  const TargetData *TD = AP.TM.getTargetData();
1107  unsigned Size = TD->getTypeAllocSize(CS->getType());
1108  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1109  uint64_t SizeSoFar = 0;
1110  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1111    const Constant *Field = CS->getOperand(i);
1112
1113    // Check if padding is needed and insert one or more 0s.
1114    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1115    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1116                        - Layout->getElementOffset(i)) - FieldSize;
1117    SizeSoFar += FieldSize + PadSize;
1118
1119    // Now print the actual field value.
1120    AP.EmitGlobalConstant(Field, AddrSpace);
1121
1122    // Insert padding - this may include padding to increase the size of the
1123    // current field up to the ABI size (if the struct is not packed) as well
1124    // as padding to ensure that the next field starts at the right offset.
1125    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1126  }
1127  assert(SizeSoFar == Layout->getSizeInBytes() &&
1128         "Layout of constant struct may be incorrect!");
1129}
1130
1131static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1132                                 AsmPrinter &AP) {
1133  // FP Constants are printed as integer constants to avoid losing
1134  // precision.
1135  if (CFP->getType()->isDoubleTy()) {
1136    if (AP.VerboseAsm) {
1137      double Val = CFP->getValueAPF().convertToDouble();
1138      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1139    }
1140
1141    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1142    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1143    return;
1144  }
1145
1146  if (CFP->getType()->isFloatTy()) {
1147    if (AP.VerboseAsm) {
1148      float Val = CFP->getValueAPF().convertToFloat();
1149      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1150    }
1151    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1152    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1153    return;
1154  }
1155
1156  if (CFP->getType()->isX86_FP80Ty()) {
1157    // all long double variants are printed as hex
1158    // api needed to prevent premature destruction
1159    APInt API = CFP->getValueAPF().bitcastToAPInt();
1160    const uint64_t *p = API.getRawData();
1161    if (AP.VerboseAsm) {
1162      // Convert to double so we can print the approximate val as a comment.
1163      APFloat DoubleVal = CFP->getValueAPF();
1164      bool ignored;
1165      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1166                        &ignored);
1167      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1168        << DoubleVal.convertToDouble() << '\n';
1169    }
1170
1171    if (AP.TM.getTargetData()->isBigEndian()) {
1172      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1173      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1174    } else {
1175      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1176      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1177    }
1178
1179    // Emit the tail padding for the long double.
1180    const TargetData &TD = *AP.TM.getTargetData();
1181    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1182                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1183    return;
1184  }
1185
1186  assert(CFP->getType()->isPPC_FP128Ty() &&
1187         "Floating point constant type not handled");
1188  // All long double variants are printed as hex api needed to prevent
1189  // premature destruction.
1190  APInt API = CFP->getValueAPF().bitcastToAPInt();
1191  const uint64_t *p = API.getRawData();
1192  if (AP.TM.getTargetData()->isBigEndian()) {
1193    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1194    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1195  } else {
1196    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1197    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1198  }
1199}
1200
1201static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1202                                       unsigned AddrSpace, AsmPrinter &AP) {
1203  const TargetData *TD = AP.TM.getTargetData();
1204  unsigned BitWidth = CI->getBitWidth();
1205  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1206
1207  // We don't expect assemblers to support integer data directives
1208  // for more than 64 bits, so we emit the data in at most 64-bit
1209  // quantities at a time.
1210  const uint64_t *RawData = CI->getValue().getRawData();
1211  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1212    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1213    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1214  }
1215}
1216
1217/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1218void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1219  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1220    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1221    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1222    return OutStreamer.EmitZeros(Size, AddrSpace);
1223  }
1224
1225  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1226    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1227    switch (Size) {
1228    case 1:
1229    case 2:
1230    case 4:
1231    case 8:
1232      if (VerboseAsm)
1233        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1234      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1235      return;
1236    default:
1237      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1238      return;
1239    }
1240  }
1241
1242  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1243    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1244
1245  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1246    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1247
1248  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1249    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1250
1251  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1252    return EmitGlobalConstantVector(V, AddrSpace, *this);
1253
1254  if (isa<ConstantPointerNull>(CV)) {
1255    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1256    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1257    return;
1258  }
1259
1260  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1261  // thread the streamer with EmitValue.
1262  OutStreamer.EmitValue(LowerConstant(CV, *this),
1263                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1264                        AddrSpace);
1265}
1266
1267void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1268  // Target doesn't support this yet!
1269  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1270}
1271
1272/// PrintSpecial - Print information related to the specified machine instr
1273/// that is independent of the operand, and may be independent of the instr
1274/// itself.  This can be useful for portably encoding the comment character
1275/// or other bits of target-specific knowledge into the asmstrings.  The
1276/// syntax used is ${:comment}.  Targets can override this to add support
1277/// for their own strange codes.
1278void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1279  if (!strcmp(Code, "private")) {
1280    O << MAI->getPrivateGlobalPrefix();
1281  } else if (!strcmp(Code, "comment")) {
1282    if (VerboseAsm)
1283      O << MAI->getCommentString();
1284  } else if (!strcmp(Code, "uid")) {
1285    // Comparing the address of MI isn't sufficient, because machineinstrs may
1286    // be allocated to the same address across functions.
1287    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1288
1289    // If this is a new LastFn instruction, bump the counter.
1290    if (LastMI != MI || LastFn != ThisF) {
1291      ++Counter;
1292      LastMI = MI;
1293      LastFn = ThisF;
1294    }
1295    O << Counter;
1296  } else {
1297    std::string msg;
1298    raw_string_ostream Msg(msg);
1299    Msg << "Unknown special formatter '" << Code
1300         << "' for machine instr: " << *MI;
1301    llvm_report_error(Msg.str());
1302  }
1303}
1304
1305/// processDebugLoc - Processes the debug information of each machine
1306/// instruction's DebugLoc.
1307void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1308                                 bool BeforePrintingInsn) {
1309  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1310      || !DW->ShouldEmitDwarfDebug())
1311    return;
1312  DebugLoc DL = MI->getDebugLoc();
1313  if (DL.isUnknown())
1314    return;
1315  DILocation CurDLT = MF->getDILocation(DL);
1316  if (!CurDLT.getScope().Verify())
1317    return;
1318
1319  if (!BeforePrintingInsn) {
1320    // After printing instruction
1321    DW->EndScope(MI);
1322  } else if (CurDLT.getNode() != PrevDLT) {
1323    MCSymbol *L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1324                                       CurDLT.getColumnNumber(),
1325                                       CurDLT.getScope().getNode());
1326    DW->BeginScope(MI, L);
1327    PrevDLT = CurDLT.getNode();
1328  }
1329}
1330
1331
1332/// printInlineAsm - This method formats and prints the specified machine
1333/// instruction that is an inline asm.
1334void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1335  unsigned NumOperands = MI->getNumOperands();
1336
1337  // Count the number of register definitions.
1338  unsigned NumDefs = 0;
1339  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1340       ++NumDefs)
1341    assert(NumDefs != NumOperands-1 && "No asm string?");
1342
1343  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1344
1345  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1346  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1347
1348  O << '\t';
1349
1350  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1351  // These are useful to see where empty asm's wound up.
1352  if (AsmStr[0] == 0) {
1353    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1354    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1355    return;
1356  }
1357
1358  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1359
1360  // The variant of the current asmprinter.
1361  int AsmPrinterVariant = MAI->getAssemblerDialect();
1362
1363  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1364  const char *LastEmitted = AsmStr; // One past the last character emitted.
1365
1366  while (*LastEmitted) {
1367    switch (*LastEmitted) {
1368    default: {
1369      // Not a special case, emit the string section literally.
1370      const char *LiteralEnd = LastEmitted+1;
1371      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1372             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1373        ++LiteralEnd;
1374      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1375        O.write(LastEmitted, LiteralEnd-LastEmitted);
1376      LastEmitted = LiteralEnd;
1377      break;
1378    }
1379    case '\n':
1380      ++LastEmitted;   // Consume newline character.
1381      O << '\n';       // Indent code with newline.
1382      break;
1383    case '$': {
1384      ++LastEmitted;   // Consume '$' character.
1385      bool Done = true;
1386
1387      // Handle escapes.
1388      switch (*LastEmitted) {
1389      default: Done = false; break;
1390      case '$':     // $$ -> $
1391        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1392          O << '$';
1393        ++LastEmitted;  // Consume second '$' character.
1394        break;
1395      case '(':             // $( -> same as GCC's { character.
1396        ++LastEmitted;      // Consume '(' character.
1397        if (CurVariant != -1) {
1398          llvm_report_error("Nested variants found in inline asm string: '"
1399                            + std::string(AsmStr) + "'");
1400        }
1401        CurVariant = 0;     // We're in the first variant now.
1402        break;
1403      case '|':
1404        ++LastEmitted;  // consume '|' character.
1405        if (CurVariant == -1)
1406          O << '|';       // this is gcc's behavior for | outside a variant
1407        else
1408          ++CurVariant;   // We're in the next variant.
1409        break;
1410      case ')':         // $) -> same as GCC's } char.
1411        ++LastEmitted;  // consume ')' character.
1412        if (CurVariant == -1)
1413          O << '}';     // this is gcc's behavior for } outside a variant
1414        else
1415          CurVariant = -1;
1416        break;
1417      }
1418      if (Done) break;
1419
1420      bool HasCurlyBraces = false;
1421      if (*LastEmitted == '{') {     // ${variable}
1422        ++LastEmitted;               // Consume '{' character.
1423        HasCurlyBraces = true;
1424      }
1425
1426      // If we have ${:foo}, then this is not a real operand reference, it is a
1427      // "magic" string reference, just like in .td files.  Arrange to call
1428      // PrintSpecial.
1429      if (HasCurlyBraces && *LastEmitted == ':') {
1430        ++LastEmitted;
1431        const char *StrStart = LastEmitted;
1432        const char *StrEnd = strchr(StrStart, '}');
1433        if (StrEnd == 0) {
1434          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1435                            + std::string(AsmStr) + "'");
1436        }
1437
1438        std::string Val(StrStart, StrEnd);
1439        PrintSpecial(MI, Val.c_str());
1440        LastEmitted = StrEnd+1;
1441        break;
1442      }
1443
1444      const char *IDStart = LastEmitted;
1445      char *IDEnd;
1446      errno = 0;
1447      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1448      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1449        llvm_report_error("Bad $ operand number in inline asm string: '"
1450                          + std::string(AsmStr) + "'");
1451      }
1452      LastEmitted = IDEnd;
1453
1454      char Modifier[2] = { 0, 0 };
1455
1456      if (HasCurlyBraces) {
1457        // If we have curly braces, check for a modifier character.  This
1458        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1459        if (*LastEmitted == ':') {
1460          ++LastEmitted;    // Consume ':' character.
1461          if (*LastEmitted == 0) {
1462            llvm_report_error("Bad ${:} expression in inline asm string: '"
1463                              + std::string(AsmStr) + "'");
1464          }
1465
1466          Modifier[0] = *LastEmitted;
1467          ++LastEmitted;    // Consume modifier character.
1468        }
1469
1470        if (*LastEmitted != '}') {
1471          llvm_report_error("Bad ${} expression in inline asm string: '"
1472                            + std::string(AsmStr) + "'");
1473        }
1474        ++LastEmitted;    // Consume '}' character.
1475      }
1476
1477      if ((unsigned)Val >= NumOperands-1) {
1478        llvm_report_error("Invalid $ operand number in inline asm string: '"
1479                          + std::string(AsmStr) + "'");
1480      }
1481
1482      // Okay, we finally have a value number.  Ask the target to print this
1483      // operand!
1484      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1485        unsigned OpNo = 1;
1486
1487        bool Error = false;
1488
1489        // Scan to find the machine operand number for the operand.
1490        for (; Val; --Val) {
1491          if (OpNo >= MI->getNumOperands()) break;
1492          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1493          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1494        }
1495
1496        if (OpNo >= MI->getNumOperands()) {
1497          Error = true;
1498        } else {
1499          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1500          ++OpNo;  // Skip over the ID number.
1501
1502          if (Modifier[0] == 'l')  // labels are target independent
1503            O << *MI->getOperand(OpNo).getMBB()->getSymbol();
1504          else {
1505            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1506            if ((OpFlags & 7) == 4) {
1507              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1508                                                Modifier[0] ? Modifier : 0);
1509            } else {
1510              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1511                                          Modifier[0] ? Modifier : 0);
1512            }
1513          }
1514        }
1515        if (Error) {
1516          std::string msg;
1517          raw_string_ostream Msg(msg);
1518          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1519          MI->print(Msg);
1520          llvm_report_error(Msg.str());
1521        }
1522      }
1523      break;
1524    }
1525    }
1526  }
1527  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1528  OutStreamer.AddBlankLine();
1529}
1530
1531/// printImplicitDef - This method prints the specified machine instruction
1532/// that is an implicit def.
1533void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1534  if (!VerboseAsm) return;
1535  O.PadToColumn(MAI->getCommentColumn());
1536  O << MAI->getCommentString() << " implicit-def: "
1537    << TRI->getName(MI->getOperand(0).getReg());
1538  OutStreamer.AddBlankLine();
1539}
1540
1541void AsmPrinter::printKill(const MachineInstr *MI) const {
1542  if (!VerboseAsm) return;
1543  O.PadToColumn(MAI->getCommentColumn());
1544  O << MAI->getCommentString() << " kill:";
1545  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1546    const MachineOperand &op = MI->getOperand(n);
1547    assert(op.isReg() && "KILL instruction must have only register operands");
1548    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1549  }
1550  OutStreamer.AddBlankLine();
1551}
1552
1553/// printLabel - This method prints a local label used by debug and
1554/// exception handling tables.
1555void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1556  MCSymbol *Sym =
1557    OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1558                                 "label" + Twine(MI->getOperand(0).getImm()));
1559  OutStreamer.EmitLabel(Sym);
1560}
1561
1562void AsmPrinter::printLabel(unsigned Id) const {
1563  MCSymbol *Sym =
1564    OutContext.GetOrCreateTemporarySymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1565                                          "label" + Twine(Id));
1566  OutStreamer.EmitLabel(Sym);
1567}
1568
1569/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1570/// instruction, using the specified assembler variant.  Targets should
1571/// override this to format as appropriate.
1572bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1573                                 unsigned AsmVariant, const char *ExtraCode) {
1574  // Target doesn't support this yet!
1575  return true;
1576}
1577
1578bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1579                                       unsigned AsmVariant,
1580                                       const char *ExtraCode) {
1581  // Target doesn't support this yet!
1582  return true;
1583}
1584
1585MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1586  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock());
1587}
1588
1589MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1590                                            const BasicBlock *BB) const {
1591  assert(BB->hasName() &&
1592         "Address of anonymous basic block not supported yet!");
1593
1594  // This code must use the function name itself, and not the function number,
1595  // since it must be possible to generate the label name from within other
1596  // functions.
1597  SmallString<60> FnName;
1598  Mang->getNameWithPrefix(FnName, F, false);
1599
1600  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1601  SmallString<60> NameResult;
1602  Mang->getNameWithPrefix(NameResult,
1603                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1604                          "_" + FnName.str() + "_" + BB->getName(),
1605                          Mangler::Private);
1606
1607  return OutContext.GetOrCreateTemporarySymbol(NameResult.str());
1608}
1609
1610/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1611MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1612  return OutContext.GetOrCreateTemporarySymbol
1613    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1614     + "_" + Twine(CPID));
1615}
1616
1617/// GetJTISymbol - Return the symbol for the specified jump table entry.
1618MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1619  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1620}
1621
1622/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1623/// FIXME: privatize to AsmPrinter.
1624MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1625  return OutContext.GetOrCreateTemporarySymbol
1626  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1627   Twine(UID) + "_set_" + Twine(MBBID));
1628}
1629
1630/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1631/// global value name as its base, with the specified suffix, and where the
1632/// symbol is forced to have private linkage if ForcePrivate is true.
1633MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1634                                                   StringRef Suffix,
1635                                                   bool ForcePrivate) const {
1636  SmallString<60> NameStr;
1637  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1638  NameStr.append(Suffix.begin(), Suffix.end());
1639  if (!GV->hasPrivateLinkage() && !ForcePrivate)
1640    return OutContext.GetOrCreateSymbol(NameStr.str());
1641  return OutContext.GetOrCreateTemporarySymbol(NameStr.str());
1642}
1643
1644/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1645/// ExternalSymbol.
1646MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1647  SmallString<60> NameStr;
1648  Mang->getNameWithPrefix(NameStr, Sym);
1649  return OutContext.GetOrCreateSymbol(NameStr.str());
1650}
1651
1652
1653
1654/// PrintParentLoopComment - Print comments about parent loops of this one.
1655static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1656                                   unsigned FunctionNumber) {
1657  if (Loop == 0) return;
1658  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1659  OS.indent(Loop->getLoopDepth()*2)
1660    << "Parent Loop BB" << FunctionNumber << "_"
1661    << Loop->getHeader()->getNumber()
1662    << " Depth=" << Loop->getLoopDepth() << '\n';
1663}
1664
1665
1666/// PrintChildLoopComment - Print comments about child loops within
1667/// the loop for this basic block, with nesting.
1668static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1669                                  unsigned FunctionNumber) {
1670  // Add child loop information
1671  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1672    OS.indent((*CL)->getLoopDepth()*2)
1673      << "Child Loop BB" << FunctionNumber << "_"
1674      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1675      << '\n';
1676    PrintChildLoopComment(OS, *CL, FunctionNumber);
1677  }
1678}
1679
1680/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1681static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1682                                        const MachineLoopInfo *LI,
1683                                        const AsmPrinter &AP) {
1684  // Add loop depth information
1685  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1686  if (Loop == 0) return;
1687
1688  MachineBasicBlock *Header = Loop->getHeader();
1689  assert(Header && "No header for loop");
1690
1691  // If this block is not a loop header, just print out what is the loop header
1692  // and return.
1693  if (Header != &MBB) {
1694    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1695                              Twine(AP.getFunctionNumber())+"_" +
1696                              Twine(Loop->getHeader()->getNumber())+
1697                              " Depth="+Twine(Loop->getLoopDepth()));
1698    return;
1699  }
1700
1701  // Otherwise, it is a loop header.  Print out information about child and
1702  // parent loops.
1703  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1704
1705  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1706
1707  OS << "=>";
1708  OS.indent(Loop->getLoopDepth()*2-2);
1709
1710  OS << "This ";
1711  if (Loop->empty())
1712    OS << "Inner ";
1713  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1714
1715  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1716}
1717
1718
1719/// EmitBasicBlockStart - This method prints the label for the specified
1720/// MachineBasicBlock, an alignment (if present) and a comment describing
1721/// it if appropriate.
1722void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1723  // Emit an alignment directive for this block, if needed.
1724  if (unsigned Align = MBB->getAlignment())
1725    EmitAlignment(Log2_32(Align));
1726
1727  // If the block has its address taken, emit a special label to satisfy
1728  // references to the block. This is done so that we don't need to
1729  // remember the number of this label, and so that we can make
1730  // forward references to labels without knowing what their numbers
1731  // will be.
1732  if (MBB->hasAddressTaken()) {
1733    const BasicBlock *BB = MBB->getBasicBlock();
1734    if (VerboseAsm)
1735      OutStreamer.AddComment("Address Taken");
1736    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1737  }
1738
1739  // Print the main label for the block.
1740  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1741    if (VerboseAsm) {
1742      // NOTE: Want this comment at start of line.
1743      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1744      if (const BasicBlock *BB = MBB->getBasicBlock())
1745        if (BB->hasName())
1746          OutStreamer.AddComment("%" + BB->getName());
1747
1748      PrintBasicBlockLoopComments(*MBB, LI, *this);
1749      OutStreamer.AddBlankLine();
1750    }
1751  } else {
1752    if (VerboseAsm) {
1753      if (const BasicBlock *BB = MBB->getBasicBlock())
1754        if (BB->hasName())
1755          OutStreamer.AddComment("%" + BB->getName());
1756      PrintBasicBlockLoopComments(*MBB, LI, *this);
1757    }
1758
1759    OutStreamer.EmitLabel(MBB->getSymbol());
1760  }
1761}
1762
1763void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1764  MCSymbolAttr Attr = MCSA_Invalid;
1765
1766  switch (Visibility) {
1767  default: break;
1768  case GlobalValue::HiddenVisibility:
1769    Attr = MAI->getHiddenVisibilityAttr();
1770    break;
1771  case GlobalValue::ProtectedVisibility:
1772    Attr = MAI->getProtectedVisibilityAttr();
1773    break;
1774  }
1775
1776  if (Attr != MCSA_Invalid)
1777    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1778}
1779
1780void AsmPrinter::printOffset(int64_t Offset) const {
1781  if (Offset > 0)
1782    O << '+' << Offset;
1783  else if (Offset < 0)
1784    O << Offset;
1785}
1786
1787/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1788/// exactly one predecessor and the control transfer mechanism between
1789/// the predecessor and this block is a fall-through.
1790bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1791    const {
1792  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1793  // then nothing falls through to it.
1794  if (MBB->isLandingPad() || MBB->pred_empty())
1795    return false;
1796
1797  // If there isn't exactly one predecessor, it can't be a fall through.
1798  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1799  ++PI2;
1800  if (PI2 != MBB->pred_end())
1801    return false;
1802
1803  // The predecessor has to be immediately before this block.
1804  const MachineBasicBlock *Pred = *PI;
1805
1806  if (!Pred->isLayoutSuccessor(MBB))
1807    return false;
1808
1809  // If the block is completely empty, then it definitely does fall through.
1810  if (Pred->empty())
1811    return true;
1812
1813  // Otherwise, check the last instruction.
1814  const MachineInstr &LastInst = Pred->back();
1815  return !LastInst.getDesc().isBarrier();
1816}
1817
1818
1819
1820GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1821  if (!S->usesMetadata())
1822    return 0;
1823
1824  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1825  if (GCPI != GCMetadataPrinters.end())
1826    return GCPI->second;
1827
1828  const char *Name = S->getName().c_str();
1829
1830  for (GCMetadataPrinterRegistry::iterator
1831         I = GCMetadataPrinterRegistry::begin(),
1832         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1833    if (strcmp(Name, I->getName()) == 0) {
1834      GCMetadataPrinter *GMP = I->instantiate();
1835      GMP->S = S;
1836      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1837      return GMP;
1838    }
1839
1840  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1841  return 0;
1842}
1843
1844