AsmPrinter.cpp revision d32c7cfa248f685e6e3064c0958dc2f0c31a4df6 
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#include "llvm/CodeGen/AsmPrinter.h"
15#include "llvm/Assembly/Writer.h"
16#include "llvm/DerivedTypes.h"
17#include "llvm/Constants.h"
18#include "llvm/Module.h"
19#include "llvm/CodeGen/DwarfWriter.h"
20#include "llvm/CodeGen/GCMetadataPrinter.h"
21#include "llvm/CodeGen/MachineConstantPool.h"
22#include "llvm/CodeGen/MachineFrameInfo.h"
23#include "llvm/CodeGen/MachineFunction.h"
24#include "llvm/CodeGen/MachineJumpTableInfo.h"
25#include "llvm/CodeGen/MachineLoopInfo.h"
26#include "llvm/CodeGen/MachineModuleInfo.h"
27#include "llvm/Analysis/DebugInfo.h"
28#include "llvm/MC/MCContext.h"
29#include "llvm/MC/MCInst.h"
30#include "llvm/MC/MCSection.h"
31#include "llvm/MC/MCStreamer.h"
32#include "llvm/MC/MCSymbol.h"
33#include "llvm/Support/CommandLine.h"
34#include "llvm/Support/ErrorHandling.h"
35#include "llvm/Support/FormattedStream.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 <cerrno>
47using namespace llvm;
48
49static cl::opt<cl::boolOrDefault>
50AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
51           cl::init(cl::BOU_UNSET));
52
53static bool getVerboseAsm(bool VDef) {
54  switch (AsmVerbose) {
55  default:
56  case cl::BOU_UNSET: return VDef;
57  case cl::BOU_TRUE:  return true;
58  case cl::BOU_FALSE: return false;
59  }
60}
61
62char AsmPrinter::ID = 0;
63AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
64                       const MCAsmInfo *T, bool VDef)
65  : MachineFunctionPass(&ID), FunctionNumber(0), O(o),
66    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
67
68    OutContext(*new MCContext()),
69    // FIXME: Pass instprinter to streamer.
70    OutStreamer(*createAsmStreamer(OutContext, O, *T,
71                                   TM.getTargetData()->isLittleEndian(),
72                                   getVerboseAsm(VDef), 0)),
73
74    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
75  DW = 0; MMI = 0;
76  VerboseAsm = getVerboseAsm(VDef);
77}
78
79AsmPrinter::~AsmPrinter() {
80  for (gcp_iterator I = GCMetadataPrinters.begin(),
81                    E = GCMetadataPrinters.end(); I != E; ++I)
82    delete I->second;
83
84  delete &OutStreamer;
85  delete &OutContext;
86}
87
88TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
89  return TM.getTargetLowering()->getObjFileLowering();
90}
91
92/// getCurrentSection() - Return the current section we are emitting to.
93const MCSection *AsmPrinter::getCurrentSection() const {
94  return OutStreamer.getCurrentSection();
95}
96
97
98void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
99  AU.setPreservesAll();
100  MachineFunctionPass::getAnalysisUsage(AU);
101  AU.addRequired<GCModuleInfo>();
102  if (VerboseAsm)
103    AU.addRequired<MachineLoopInfo>();
104}
105
106bool AsmPrinter::doInitialization(Module &M) {
107  // Initialize TargetLoweringObjectFile.
108  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
109    .Initialize(OutContext, TM);
110
111  Mang = new Mangler(*MAI);
112
113  // Allow the target to emit any magic that it wants at the start of the file.
114  EmitStartOfAsmFile(M);
115
116  if (MAI->hasSingleParameterDotFile()) {
117    /* Very minimal debug info. It is ignored if we emit actual
118       debug info. If we don't, this at least helps the user find where
119       a function came from. */
120    O << "\t.file\t\"" << M.getModuleIdentifier() << "\"\n";
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  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
136  if (MMI)
137    MMI->AnalyzeModule(M);
138  DW = getAnalysisIfAvailable<DwarfWriter>();
139  if (DW)
140    DW->BeginModule(&M, MMI, O, this, MAI);
141
142  return false;
143}
144
145/// EmitGlobalVariable - Emit the specified global variable to the .s file.
146void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
147  if (!GV->hasInitializer())   // External globals require no code.
148    return;
149
150  // Check to see if this is a special global used by LLVM, if so, emit it.
151  if (EmitSpecialLLVMGlobal(GV))
152    return;
153
154  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
155  printVisibility(GVSym, GV->getVisibility());
156
157  if (MAI->hasDotTypeDotSizeDirective()) {
158    O << "\t.type\t" << *GVSym;
159    if (MAI->getCommentString()[0] != '@')
160      O << ",@object\n";
161    else
162      O << ",%object\n";
163  }
164
165  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
166
167  const TargetData *TD = TM.getTargetData();
168  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
169  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
170
171  // Handle common and BSS local symbols (.lcomm).
172  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
173    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
174
175    if (VerboseAsm) {
176      O.PadToColumn(MAI->getCommentColumn());
177      O << MAI->getCommentString() << ' ';
178      WriteAsOperand(O, GV, /*PrintType=*/false, GV->getParent());
179      O << '\n';
180    }
181
182    // Handle common symbols.
183    if (GVKind.isCommon()) {
184      // .comm _foo, 42, 4
185      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
186      return;
187    }
188
189    // Handle local BSS symbols.
190    if (MAI->hasMachoZeroFillDirective()) {
191      const MCSection *TheSection =
192        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
193      // .zerofill __DATA, __bss, _foo, 400, 5
194      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
195      return;
196    }
197
198    if (const char *LComm = MAI->getLCOMMDirective()) {
199      // .lcomm _foo, 42
200      O << LComm << *GVSym << ',' << Size;
201      O << '\n';
202      return;
203    }
204
205    // .local _foo
206    O << "\t.local\t" << *GVSym << '\n';
207    // .comm _foo, 42, 4
208    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
209    return;
210  }
211
212  const MCSection *TheSection =
213    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
214
215  // Handle the zerofill directive on darwin, which is a special form of BSS
216  // emission.
217  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
218    // .globl _foo
219    OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::Global);
220    // .zerofill __DATA, __common, _foo, 400, 5
221    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
222    return;
223  }
224
225  OutStreamer.SwitchSection(TheSection);
226
227  // TODO: Factor into an 'emit linkage' thing that is shared with function
228  // bodies.
229  switch (GV->getLinkage()) {
230  case GlobalValue::CommonLinkage:
231  case GlobalValue::LinkOnceAnyLinkage:
232  case GlobalValue::LinkOnceODRLinkage:
233  case GlobalValue::WeakAnyLinkage:
234  case GlobalValue::WeakODRLinkage:
235  case GlobalValue::LinkerPrivateLinkage:
236    if (MAI->getWeakDefDirective() != 0) {
237      // .globl _foo
238      OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::Global);
239      // .weak_definition _foo
240      OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::WeakDefinition);
241    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
242      // .globl _foo
243      OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::Global);
244      // .linkonce same_size
245      O << LinkOnce;
246    } else {
247      // .weak _foo
248      OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::Weak);
249    }
250    break;
251  case GlobalValue::DLLExportLinkage:
252  case GlobalValue::AppendingLinkage:
253    // FIXME: appending linkage variables should go into a section of
254    // their name or something.  For now, just emit them as external.
255  case GlobalValue::ExternalLinkage:
256    // If external or appending, declare as a global symbol.
257    // .globl _foo
258    OutStreamer.EmitSymbolAttribute(GVSym, MCStreamer::Global);
259    break;
260  case GlobalValue::PrivateLinkage:
261  case GlobalValue::InternalLinkage:
262     break;
263  default:
264    llvm_unreachable("Unknown linkage type!");
265  }
266
267  EmitAlignment(AlignLog, GV);
268  if (VerboseAsm) {
269    O.PadToColumn(MAI->getCommentColumn());
270    O << MAI->getCommentString() << ' ';
271    WriteAsOperand(O, GV, /*PrintType=*/false, GV->getParent());
272    O << '\n';
273  }
274  OutStreamer.EmitLabel(GVSym);
275
276  EmitGlobalConstant(GV->getInitializer());
277
278  if (MAI->hasDotTypeDotSizeDirective())
279    O << "\t.size\t" << *GVSym << ", " << Size << '\n';
280}
281
282
283bool AsmPrinter::doFinalization(Module &M) {
284  // Emit global variables.
285  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
286       I != E; ++I)
287    EmitGlobalVariable(I);
288
289  // Emit final debug information.
290  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
291    DW->EndModule();
292
293  // If the target wants to know about weak references, print them all.
294  if (MAI->getWeakRefDirective()) {
295    // FIXME: This is not lazy, it would be nice to only print weak references
296    // to stuff that is actually used.  Note that doing so would require targets
297    // to notice uses in operands (due to constant exprs etc).  This should
298    // happen with the MC stuff eventually.
299
300    // Print out module-level global variables here.
301    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
302         I != E; ++I) {
303      if (!I->hasExternalWeakLinkage()) continue;
304      O << MAI->getWeakRefDirective() << *GetGlobalValueSymbol(I) << '\n';
305    }
306
307    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
308      if (!I->hasExternalWeakLinkage()) continue;
309      O << MAI->getWeakRefDirective() << *GetGlobalValueSymbol(I) << '\n';
310    }
311  }
312
313  if (MAI->getSetDirective()) {
314    O << '\n';
315    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
316         I != E; ++I) {
317      MCSymbol *Name = GetGlobalValueSymbol(I);
318
319      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
320      MCSymbol *Target = GetGlobalValueSymbol(GV);
321
322      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
323        O << "\t.globl\t" << *Name << '\n';
324      else if (I->hasWeakLinkage())
325        O << MAI->getWeakRefDirective() << *Name << '\n';
326      else
327        assert(I->hasLocalLinkage() && "Invalid alias linkage");
328
329      printVisibility(Name, I->getVisibility());
330
331      O << MAI->getSetDirective() << ' ' << *Name << ", " << *Target << '\n';
332    }
333  }
334
335  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
336  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
337  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
338    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
339      MP->finishAssembly(O, *this, *MAI);
340
341  // If we don't have any trampolines, then we don't require stack memory
342  // to be executable. Some targets have a directive to declare this.
343  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
344  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
345    if (MAI->getNonexecutableStackDirective())
346      O << MAI->getNonexecutableStackDirective() << '\n';
347
348
349  // Allow the target to emit any magic that it wants at the end of the file,
350  // after everything else has gone out.
351  EmitEndOfAsmFile(M);
352
353  delete Mang; Mang = 0;
354  DW = 0; MMI = 0;
355
356  OutStreamer.Finish();
357  return false;
358}
359
360void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
361  // Get the function symbol.
362  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
363  IncrementFunctionNumber();
364
365  if (VerboseAsm)
366    LI = &getAnalysis<MachineLoopInfo>();
367}
368
369namespace {
370  // SectionCPs - Keep track the alignment, constpool entries per Section.
371  struct SectionCPs {
372    const MCSection *S;
373    unsigned Alignment;
374    SmallVector<unsigned, 4> CPEs;
375    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
376  };
377}
378
379/// EmitConstantPool - Print to the current output stream assembly
380/// representations of the constants in the constant pool MCP. This is
381/// used to print out constants which have been "spilled to memory" by
382/// the code generator.
383///
384void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
385  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
386  if (CP.empty()) return;
387
388  // Calculate sections for constant pool entries. We collect entries to go into
389  // the same section together to reduce amount of section switch statements.
390  SmallVector<SectionCPs, 4> CPSections;
391  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
392    const MachineConstantPoolEntry &CPE = CP[i];
393    unsigned Align = CPE.getAlignment();
394
395    SectionKind Kind;
396    switch (CPE.getRelocationInfo()) {
397    default: llvm_unreachable("Unknown section kind");
398    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
399    case 1:
400      Kind = SectionKind::getReadOnlyWithRelLocal();
401      break;
402    case 0:
403    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
404    case 4:  Kind = SectionKind::getMergeableConst4(); break;
405    case 8:  Kind = SectionKind::getMergeableConst8(); break;
406    case 16: Kind = SectionKind::getMergeableConst16();break;
407    default: Kind = SectionKind::getMergeableConst(); break;
408    }
409    }
410
411    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
412
413    // The number of sections are small, just do a linear search from the
414    // last section to the first.
415    bool Found = false;
416    unsigned SecIdx = CPSections.size();
417    while (SecIdx != 0) {
418      if (CPSections[--SecIdx].S == S) {
419        Found = true;
420        break;
421      }
422    }
423    if (!Found) {
424      SecIdx = CPSections.size();
425      CPSections.push_back(SectionCPs(S, Align));
426    }
427
428    if (Align > CPSections[SecIdx].Alignment)
429      CPSections[SecIdx].Alignment = Align;
430    CPSections[SecIdx].CPEs.push_back(i);
431  }
432
433  // Now print stuff into the calculated sections.
434  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
435    OutStreamer.SwitchSection(CPSections[i].S);
436    EmitAlignment(Log2_32(CPSections[i].Alignment));
437
438    unsigned Offset = 0;
439    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
440      unsigned CPI = CPSections[i].CPEs[j];
441      MachineConstantPoolEntry CPE = CP[CPI];
442
443      // Emit inter-object padding for alignment.
444      unsigned AlignMask = CPE.getAlignment() - 1;
445      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
446      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
447
448      const Type *Ty = CPE.getType();
449      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
450
451      O << MAI->getPrivateGlobalPrefix() << "CPI" << getFunctionNumber() << '_'
452        << CPI << ':';
453      if (VerboseAsm) {
454        O.PadToColumn(MAI->getCommentColumn());
455        O << MAI->getCommentString() << " constant ";
456        WriteTypeSymbolic(O, CPE.getType(), MF->getFunction()->getParent());
457      }
458      O << '\n';
459      if (CPE.isMachineConstantPoolEntry())
460        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
461      else
462        EmitGlobalConstant(CPE.Val.ConstVal);
463    }
464  }
465}
466
467/// EmitJumpTableInfo - Print assembly representations of the jump tables used
468/// by the current function to the current output stream.
469///
470void AsmPrinter::EmitJumpTableInfo(MachineJumpTableInfo *MJTI,
471                                   MachineFunction &MF) {
472  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
473  if (JT.empty()) return;
474
475  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
476
477  // Pick the directive to use to print the jump table entries, and switch to
478  // the appropriate section.
479  TargetLowering *LoweringInfo = TM.getTargetLowering();
480
481  const Function *F = MF.getFunction();
482  bool JTInDiffSection = false;
483  if (F->isWeakForLinker() ||
484      (IsPic && !LoweringInfo->usesGlobalOffsetTable())) {
485    // In PIC mode, we need to emit the jump table to the same section as the
486    // function body itself, otherwise the label differences won't make sense.
487    // We should also do if the section name is NULL or function is declared in
488    // discardable section.
489    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang,
490                                                                    TM));
491  } else {
492    // Otherwise, drop it in the readonly section.
493    const MCSection *ReadOnlySection =
494      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
495    OutStreamer.SwitchSection(ReadOnlySection);
496    JTInDiffSection = true;
497  }
498
499  EmitAlignment(Log2_32(MJTI->getAlignment()));
500
501  for (unsigned i = 0, e = JT.size(); i != e; ++i) {
502    const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
503
504    // If this jump table was deleted, ignore it.
505    if (JTBBs.empty()) continue;
506
507    // For PIC codegen, if possible we want to use the SetDirective to reduce
508    // the number of relocations the assembler will generate for the jump table.
509    // Set directives are all printed before the jump table itself.
510    SmallPtrSet<MachineBasicBlock*, 16> EmittedSets;
511    if (MAI->getSetDirective() && IsPic)
512      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
513        if (EmittedSets.insert(JTBBs[ii]))
514          printPICJumpTableSetLabel(i, JTBBs[ii]);
515
516    // On some targets (e.g. Darwin) we want to emit two consequtive labels
517    // before each jump table.  The first label is never referenced, but tells
518    // the assembler and linker the extents of the jump table object.  The
519    // second label is actually referenced by the code.
520    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0]) {
521      O << MAI->getLinkerPrivateGlobalPrefix()
522        << "JTI" << getFunctionNumber() << '_' << i << ":\n";
523    }
524
525    O << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
526      << '_' << i << ":\n";
527
528    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
529      printPICJumpTableEntry(MJTI, JTBBs[ii], i);
530      O << '\n';
531    }
532  }
533}
534
535void AsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
536                                        const MachineBasicBlock *MBB,
537                                        unsigned uid)  const {
538  bool isPIC = TM.getRelocationModel() == Reloc::PIC_;
539
540  // Use JumpTableDirective otherwise honor the entry size from the jump table
541  // info.
542  const char *JTEntryDirective = MAI->getJumpTableDirective(isPIC);
543  bool HadJTEntryDirective = JTEntryDirective != NULL;
544  if (!HadJTEntryDirective) {
545    JTEntryDirective = MJTI->getEntrySize() == 4 ?
546      MAI->getData32bitsDirective() : MAI->getData64bitsDirective();
547  }
548
549  O << JTEntryDirective << ' ';
550
551  // If we have emitted set directives for the jump table entries, print
552  // them rather than the entries themselves.  If we're emitting PIC, then
553  // emit the table entries as differences between two text section labels.
554  // If we're emitting non-PIC code, then emit the entries as direct
555  // references to the target basic blocks.
556  if (!isPIC) {
557    O << *GetMBBSymbol(MBB->getNumber());
558  } else if (MAI->getSetDirective()) {
559    O << MAI->getPrivateGlobalPrefix() << getFunctionNumber()
560      << '_' << uid << "_set_" << MBB->getNumber();
561  } else {
562    O << *GetMBBSymbol(MBB->getNumber());
563    // If the arch uses custom Jump Table directives, don't calc relative to
564    // JT
565    if (!HadJTEntryDirective)
566      O << '-' << MAI->getPrivateGlobalPrefix() << "JTI"
567        << getFunctionNumber() << '_' << uid;
568  }
569}
570
571
572/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
573/// special global used by LLVM.  If so, emit it and return true, otherwise
574/// do nothing and return false.
575bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
576  if (GV->getName() == "llvm.used") {
577    if (MAI->getUsedDirective() != 0)    // No need to emit this at all.
578      EmitLLVMUsedList(GV->getInitializer());
579    return true;
580  }
581
582  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
583  if (GV->getSection() == "llvm.metadata" ||
584      GV->hasAvailableExternallyLinkage())
585    return true;
586
587  if (!GV->hasAppendingLinkage()) return false;
588
589  assert(GV->hasInitializer() && "Not a special LLVM global!");
590
591  const TargetData *TD = TM.getTargetData();
592  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
593  if (GV->getName() == "llvm.global_ctors") {
594    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
595    EmitAlignment(Align, 0);
596    EmitXXStructorList(GV->getInitializer());
597
598    if (TM.getRelocationModel() == Reloc::Static &&
599        MAI->hasStaticCtorDtorReferenceInStaticMode())
600      O << ".reference .constructors_used\n";
601    return true;
602  }
603
604  if (GV->getName() == "llvm.global_dtors") {
605    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
606    EmitAlignment(Align, 0);
607    EmitXXStructorList(GV->getInitializer());
608
609    if (TM.getRelocationModel() == Reloc::Static &&
610        MAI->hasStaticCtorDtorReferenceInStaticMode())
611      O << ".reference .destructors_used\n";
612    return true;
613  }
614
615  return false;
616}
617
618/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
619/// global in the specified llvm.used list for which emitUsedDirectiveFor
620/// is true, as being used with this directive.
621void AsmPrinter::EmitLLVMUsedList(Constant *List) {
622  const char *Directive = MAI->getUsedDirective();
623
624  // Should be an array of 'i8*'.
625  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
626  if (InitList == 0) return;
627
628  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
629    const GlobalValue *GV =
630      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
631    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang)) {
632      O << Directive;
633      EmitConstantValueOnly(InitList->getOperand(i));
634      O << '\n';
635    }
636  }
637}
638
639/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
640/// function pointers, ignoring the init priority.
641void AsmPrinter::EmitXXStructorList(Constant *List) {
642  // Should be an array of '{ int, void ()* }' structs.  The first value is the
643  // init priority, which we ignore.
644  if (!isa<ConstantArray>(List)) return;
645  ConstantArray *InitList = cast<ConstantArray>(List);
646  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
647    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
648      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
649
650      if (CS->getOperand(1)->isNullValue())
651        return;  // Found a null terminator, exit printing.
652      // Emit the function pointer.
653      EmitGlobalConstant(CS->getOperand(1));
654    }
655}
656
657
658//===----------------------------------------------------------------------===//
659/// LEB 128 number encoding.
660
661/// PrintULEB128 - Print a series of hexadecimal values (separated by commas)
662/// representing an unsigned leb128 value.
663void AsmPrinter::PrintULEB128(unsigned Value) const {
664  do {
665    unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
666    Value >>= 7;
667    if (Value) Byte |= 0x80;
668    PrintHex(Byte);
669    if (Value) O << ", ";
670  } while (Value);
671}
672
673/// PrintSLEB128 - Print a series of hexadecimal values (separated by commas)
674/// representing a signed leb128 value.
675void AsmPrinter::PrintSLEB128(int Value) const {
676  int Sign = Value >> (8 * sizeof(Value) - 1);
677  bool IsMore;
678
679  do {
680    unsigned char Byte = static_cast<unsigned char>(Value & 0x7f);
681    Value >>= 7;
682    IsMore = Value != Sign || ((Byte ^ Sign) & 0x40) != 0;
683    if (IsMore) Byte |= 0x80;
684    PrintHex(Byte);
685    if (IsMore) O << ", ";
686  } while (IsMore);
687}
688
689//===--------------------------------------------------------------------===//
690// Emission and print routines
691//
692
693/// PrintHex - Print a value as a hexadecimal value.
694///
695void AsmPrinter::PrintHex(uint64_t Value) const {
696  O << "0x";
697  O.write_hex(Value);
698}
699
700/// EOL - Print a newline character to asm stream.  If a comment is present
701/// then it will be printed first.  Comments should not contain '\n'.
702void AsmPrinter::EOL() const {
703  O << '\n';
704}
705
706void AsmPrinter::EOL(const Twine &Comment) const {
707  if (VerboseAsm && !Comment.isTriviallyEmpty()) {
708    O.PadToColumn(MAI->getCommentColumn());
709    O << MAI->getCommentString() << ' ' << Comment;
710  }
711  O << '\n';
712}
713
714static const char *DecodeDWARFEncoding(unsigned Encoding) {
715  switch (Encoding) {
716  case dwarf::DW_EH_PE_absptr:
717    return "absptr";
718  case dwarf::DW_EH_PE_omit:
719    return "omit";
720  case dwarf::DW_EH_PE_pcrel:
721    return "pcrel";
722  case dwarf::DW_EH_PE_udata4:
723    return "udata4";
724  case dwarf::DW_EH_PE_udata8:
725    return "udata8";
726  case dwarf::DW_EH_PE_sdata4:
727    return "sdata4";
728  case dwarf::DW_EH_PE_sdata8:
729    return "sdata8";
730  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata4:
731    return "pcrel udata4";
732  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata4:
733    return "pcrel sdata4";
734  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_udata8:
735    return "pcrel udata8";
736  case dwarf::DW_EH_PE_pcrel | dwarf::DW_EH_PE_sdata8:
737    return "pcrel sdata8";
738  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata4:
739    return "indirect pcrel udata4";
740  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata4:
741    return "indirect pcrel sdata4";
742  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_udata8:
743    return "indirect pcrel udata8";
744  case dwarf::DW_EH_PE_indirect | dwarf::DW_EH_PE_pcrel |dwarf::DW_EH_PE_sdata8:
745    return "indirect pcrel sdata8";
746  }
747
748  return 0;
749}
750
751void AsmPrinter::EOL(const Twine &Comment, unsigned Encoding) const {
752  if (VerboseAsm && !Comment.isTriviallyEmpty()) {
753    O.PadToColumn(MAI->getCommentColumn());
754    O << MAI->getCommentString()
755      << ' '
756      << Comment;
757
758    if (const char *EncStr = DecodeDWARFEncoding(Encoding))
759      O << " (" << EncStr << ')';
760  }
761  O << '\n';
762}
763
764/// EmitULEB128Bytes - Emit an assembler byte data directive to compose an
765/// unsigned leb128 value.
766void AsmPrinter::EmitULEB128Bytes(unsigned Value) const {
767  if (MAI->hasLEB128()) {
768    O << "\t.uleb128\t"
769      << Value;
770  } else {
771    O << MAI->getData8bitsDirective();
772    PrintULEB128(Value);
773  }
774}
775
776/// EmitSLEB128Bytes - print an assembler byte data directive to compose a
777/// signed leb128 value.
778void AsmPrinter::EmitSLEB128Bytes(int Value) const {
779  if (MAI->hasLEB128()) {
780    O << "\t.sleb128\t"
781      << Value;
782  } else {
783    O << MAI->getData8bitsDirective();
784    PrintSLEB128(Value);
785  }
786}
787
788/// EmitInt8 - Emit a byte directive and value.
789///
790void AsmPrinter::EmitInt8(int Value) const {
791  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
792}
793
794/// EmitInt16 - Emit a short directive and value.
795///
796void AsmPrinter::EmitInt16(int Value) const {
797  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
798}
799
800/// EmitInt32 - Emit a long directive and value.
801///
802void AsmPrinter::EmitInt32(int Value) const {
803  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
804}
805
806/// EmitInt64 - Emit a long long directive and value.
807///
808void AsmPrinter::EmitInt64(uint64_t Value) const {
809  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
810}
811
812/// toOctal - Convert the low order bits of X into an octal digit.
813///
814static inline char toOctal(int X) {
815  return (X&7)+'0';
816}
817
818/// printStringChar - Print a char, escaped if necessary.
819///
820static void printStringChar(formatted_raw_ostream &O, unsigned char C) {
821  if (C == '"') {
822    O << "\\\"";
823  } else if (C == '\\') {
824    O << "\\\\";
825  } else if (isprint((unsigned char)C)) {
826    O << C;
827  } else {
828    switch(C) {
829    case '\b': O << "\\b"; break;
830    case '\f': O << "\\f"; break;
831    case '\n': O << "\\n"; break;
832    case '\r': O << "\\r"; break;
833    case '\t': O << "\\t"; break;
834    default:
835      O << '\\';
836      O << toOctal(C >> 6);
837      O << toOctal(C >> 3);
838      O << toOctal(C >> 0);
839      break;
840    }
841  }
842}
843
844/// EmitString - Emit a string with quotes and a null terminator.
845/// Special characters are emitted properly.
846/// \literal (Eg. '\t') \endliteral
847void AsmPrinter::EmitString(const StringRef String) const {
848  EmitString(String.data(), String.size());
849}
850
851void AsmPrinter::EmitString(const char *String, unsigned Size) const {
852  const char* AscizDirective = MAI->getAscizDirective();
853  if (AscizDirective)
854    O << AscizDirective;
855  else
856    O << MAI->getAsciiDirective();
857  O << '\"';
858  for (unsigned i = 0; i < Size; ++i)
859    printStringChar(O, String[i]);
860  if (AscizDirective)
861    O << '\"';
862  else
863    O << "\\0\"";
864}
865
866
867/// EmitFile - Emit a .file directive.
868void AsmPrinter::EmitFile(unsigned Number, StringRef Name) const {
869  O << "\t.file\t" << Number << " \"";
870  for (unsigned i = 0, N = Name.size(); i < N; ++i)
871    printStringChar(O, Name[i]);
872  O << '\"';
873}
874
875
876//===----------------------------------------------------------------------===//
877
878// EmitAlignment - Emit an alignment directive to the specified power of
879// two boundary.  For example, if you pass in 3 here, you will get an 8
880// byte alignment.  If a global value is specified, and if that global has
881// an explicit alignment requested, it will unconditionally override the
882// alignment request.  However, if ForcedAlignBits is specified, this value
883// has final say: the ultimate alignment will be the max of ForcedAlignBits
884// and the alignment computed with NumBits and the global.
885//
886// The algorithm is:
887//     Align = NumBits;
888//     if (GV && GV->hasalignment) Align = GV->getalignment();
889//     Align = std::max(Align, ForcedAlignBits);
890//
891void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
892                               unsigned ForcedAlignBits,
893                               bool UseFillExpr) const {
894  if (GV && GV->getAlignment())
895    NumBits = Log2_32(GV->getAlignment());
896  NumBits = std::max(NumBits, ForcedAlignBits);
897
898  if (NumBits == 0) return;   // No need to emit alignment.
899
900  unsigned FillValue = 0;
901  if (getCurrentSection()->getKind().isText())
902    FillValue = MAI->getTextAlignFillValue();
903
904  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
905}
906
907// Print out the specified constant, without a storage class.  Only the
908// constants valid in constant expressions can occur here.
909void AsmPrinter::EmitConstantValueOnly(const Constant *CV) {
910  if (CV->isNullValue() || isa<UndefValue>(CV)) {
911    O << '0';
912    return;
913  }
914
915  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
916    O << CI->getZExtValue();
917    return;
918  }
919
920  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV)) {
921    // This is a constant address for a global variable or function. Use the
922    // name of the variable or function as the address value.
923    O << *GetGlobalValueSymbol(GV);
924    return;
925  }
926
927  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV)) {
928    O << *GetBlockAddressSymbol(BA);
929    return;
930  }
931
932  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
933  if (CE == 0) {
934    llvm_unreachable("Unknown constant value!");
935    O << '0';
936    return;
937  }
938
939  switch (CE->getOpcode()) {
940  case Instruction::ZExt:
941  case Instruction::SExt:
942  case Instruction::FPTrunc:
943  case Instruction::FPExt:
944  case Instruction::UIToFP:
945  case Instruction::SIToFP:
946  case Instruction::FPToUI:
947  case Instruction::FPToSI:
948  default:
949    llvm_unreachable("FIXME: Don't support this constant cast expr");
950  case Instruction::GetElementPtr: {
951    // generate a symbolic expression for the byte address
952    const TargetData *TD = TM.getTargetData();
953    const Constant *ptrVal = CE->getOperand(0);
954    SmallVector<Value*, 8> idxVec(CE->op_begin()+1, CE->op_end());
955    int64_t Offset = TD->getIndexedOffset(ptrVal->getType(), &idxVec[0],
956                                          idxVec.size());
957    if (Offset == 0)
958      return EmitConstantValueOnly(ptrVal);
959
960    // Truncate/sext the offset to the pointer size.
961    if (TD->getPointerSizeInBits() != 64) {
962      int SExtAmount = 64-TD->getPointerSizeInBits();
963      Offset = (Offset << SExtAmount) >> SExtAmount;
964    }
965
966    if (Offset)
967      O << '(';
968    EmitConstantValueOnly(ptrVal);
969    if (Offset > 0)
970      O << ") + " << Offset;
971    else
972      O << ") - " << -Offset;
973    return;
974  }
975  case Instruction::BitCast:
976    return EmitConstantValueOnly(CE->getOperand(0));
977
978  case Instruction::IntToPtr: {
979    // Handle casts to pointers by changing them into casts to the appropriate
980    // integer type.  This promotes constant folding and simplifies this code.
981    const TargetData *TD = TM.getTargetData();
982    Constant *Op = CE->getOperand(0);
983    Op = ConstantExpr::getIntegerCast(Op, TD->getIntPtrType(CV->getContext()),
984                                      false/*ZExt*/);
985    return EmitConstantValueOnly(Op);
986  }
987
988  case Instruction::PtrToInt: {
989    // Support only foldable casts to/from pointers that can be eliminated by
990    // changing the pointer to the appropriately sized integer type.
991    Constant *Op = CE->getOperand(0);
992    const Type *Ty = CE->getType();
993    const TargetData *TD = TM.getTargetData();
994
995    // We can emit the pointer value into this slot if the slot is an
996    // integer slot greater or equal to the size of the pointer.
997    if (TD->getTypeAllocSize(Ty) == TD->getTypeAllocSize(Op->getType()))
998      return EmitConstantValueOnly(Op);
999
1000    O << "((";
1001    EmitConstantValueOnly(Op);
1002    APInt ptrMask =
1003      APInt::getAllOnesValue(TD->getTypeAllocSizeInBits(Op->getType()));
1004
1005    SmallString<40> S;
1006    ptrMask.toStringUnsigned(S);
1007    O << ") & " << S.str() << ')';
1008    return;
1009  }
1010
1011  case Instruction::Trunc:
1012    // We emit the value and depend on the assembler to truncate the generated
1013    // expression properly.  This is important for differences between
1014    // blockaddress labels.  Since the two labels are in the same function, it
1015    // is reasonable to treat their delta as a 32-bit value.
1016    return EmitConstantValueOnly(CE->getOperand(0));
1017
1018  case Instruction::Add:
1019  case Instruction::Sub:
1020  case Instruction::And:
1021  case Instruction::Or:
1022  case Instruction::Xor:
1023    O << '(';
1024    EmitConstantValueOnly(CE->getOperand(0));
1025    O << ')';
1026    switch (CE->getOpcode()) {
1027    case Instruction::Add:
1028     O << " + ";
1029     break;
1030    case Instruction::Sub:
1031     O << " - ";
1032     break;
1033    case Instruction::And:
1034     O << " & ";
1035     break;
1036    case Instruction::Or:
1037     O << " | ";
1038     break;
1039    case Instruction::Xor:
1040     O << " ^ ";
1041     break;
1042    default:
1043     break;
1044    }
1045    O << '(';
1046    EmitConstantValueOnly(CE->getOperand(1));
1047    O << ')';
1048    break;
1049  }
1050}
1051
1052/// printAsCString - Print the specified array as a C compatible string, only if
1053/// the predicate isString is true.
1054///
1055static void printAsCString(formatted_raw_ostream &O, const ConstantArray *CVA,
1056                           unsigned LastElt) {
1057  assert(CVA->isString() && "Array is not string compatible!");
1058
1059  O << '\"';
1060  for (unsigned i = 0; i != LastElt; ++i) {
1061    unsigned char C =
1062        (unsigned char)cast<ConstantInt>(CVA->getOperand(i))->getZExtValue();
1063    printStringChar(O, C);
1064  }
1065  O << '\"';
1066}
1067
1068/// EmitString - Emit a zero-byte-terminated string constant.
1069///
1070void AsmPrinter::EmitString(const ConstantArray *CVA) const {
1071  unsigned NumElts = CVA->getNumOperands();
1072  if (MAI->getAscizDirective() && NumElts &&
1073      cast<ConstantInt>(CVA->getOperand(NumElts-1))->getZExtValue() == 0) {
1074    O << MAI->getAscizDirective();
1075    printAsCString(O, CVA, NumElts-1);
1076  } else {
1077    O << MAI->getAsciiDirective();
1078    printAsCString(O, CVA, NumElts);
1079  }
1080  O << '\n';
1081}
1082
1083static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1084                                    AsmPrinter &AP) {
1085  if (AddrSpace == 0 && CA->isString()) {
1086    AP.EmitString(CA);
1087  } else { // Not a string.  Print the values in successive locations
1088    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1089      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1090  }
1091}
1092
1093static void EmitGlobalConstantVector(const ConstantVector *CV,
1094                                     unsigned AddrSpace, AsmPrinter &AP) {
1095  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1096    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1097}
1098
1099static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1100                                     unsigned AddrSpace, AsmPrinter &AP) {
1101  // Print the fields in successive locations. Pad to align if needed!
1102  const TargetData *TD = AP.TM.getTargetData();
1103  unsigned Size = TD->getTypeAllocSize(CS->getType());
1104  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1105  uint64_t SizeSoFar = 0;
1106  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1107    const Constant *Field = CS->getOperand(i);
1108
1109    // Check if padding is needed and insert one or more 0s.
1110    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1111    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1112                        - Layout->getElementOffset(i)) - FieldSize;
1113    SizeSoFar += FieldSize + PadSize;
1114
1115    // Now print the actual field value.
1116    AP.EmitGlobalConstant(Field, AddrSpace);
1117
1118    // Insert padding - this may include padding to increase the size of the
1119    // current field up to the ABI size (if the struct is not packed) as well
1120    // as padding to ensure that the next field starts at the right offset.
1121    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1122  }
1123  assert(SizeSoFar == Layout->getSizeInBytes() &&
1124         "Layout of constant struct may be incorrect!");
1125}
1126
1127static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1128                                 AsmPrinter &AP) {
1129  SmallString<128> TmpBuffer;
1130
1131  // FP Constants are printed as integer constants to avoid losing
1132  // precision.
1133  if (CFP->getType()->isDoubleTy()) {
1134    if (AP.VerboseAsm) {
1135      raw_svector_ostream OS(TmpBuffer);
1136      double Val = CFP->getValueAPF().convertToDouble();  // for comment only
1137      OS << "double " << Val;
1138      AP.OutStreamer.AddComment(OS.str());
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();  // for comment only
1149      AP.O.PadToColumn(AP.MAI->getCommentColumn());
1150      AP.O << AP.MAI->getCommentString() << " float " << Val << '\n';
1151    }
1152    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1153    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1154    return;
1155  }
1156
1157  if (CFP->getType()->isX86_FP80Ty()) {
1158    // all long double variants are printed as hex
1159    // api needed to prevent premature destruction
1160    APInt API = CFP->getValueAPF().bitcastToAPInt();
1161    const uint64_t *p = API.getRawData();
1162    if (AP.VerboseAsm) {
1163      // Convert to double so we can print the approximate val as a comment.
1164      APFloat DoubleVal = CFP->getValueAPF();
1165      bool ignored;
1166      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1167                        &ignored);
1168      AP.O.PadToColumn(AP.MAI->getCommentColumn());
1169      AP.O << AP.MAI->getCommentString() << " x86_fp80 ~= "
1170           << DoubleVal.convertToDouble() << '\n';
1171    }
1172
1173    if (AP.TM.getTargetData()->isBigEndian()) {
1174      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1175      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1176    } else {
1177      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1178      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1179    }
1180
1181    // Emit the tail padding for the long double.
1182    const TargetData &TD = *AP.TM.getTargetData();
1183    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1184                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1185    return;
1186  }
1187
1188  assert(CFP->getType()->isPPC_FP128Ty() &&
1189         "Floating point constant type not handled");
1190  // All long double variants are printed as hex api needed to prevent
1191  // premature destruction.
1192  APInt API = CFP->getValueAPF().bitcastToAPInt();
1193  const uint64_t *p = API.getRawData();
1194  if (AP.TM.getTargetData()->isBigEndian()) {
1195    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1196    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1197  } else {
1198    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1199    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1200  }
1201}
1202
1203static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1204                                       unsigned AddrSpace, AsmPrinter &AP) {
1205  const TargetData *TD = AP.TM.getTargetData();
1206  unsigned BitWidth = CI->getBitWidth();
1207  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1208
1209  // We don't expect assemblers to support integer data directives
1210  // for more than 64 bits, so we emit the data in at most 64-bit
1211  // quantities at a time.
1212  const uint64_t *RawData = CI->getValue().getRawData();
1213  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1214    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1215    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1216  }
1217}
1218
1219/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1220void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1221  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1222    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1223    return OutStreamer.EmitZeros(Size, AddrSpace);
1224  }
1225
1226  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1227    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1228    switch (Size) {
1229    case 1:
1230    case 2:
1231    case 4:
1232    case 8:
1233      if (VerboseAsm) {
1234        O.PadToColumn(MAI->getCommentColumn());
1235        O << MAI->getCommentString() << " 0x";
1236        O.write_hex(CI->getZExtValue());
1237        O << '\n';
1238      }
1239      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1240      return;
1241    default:
1242      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1243      return;
1244    }
1245  }
1246
1247  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1248    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1249
1250  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1251    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1252
1253  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1254    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1255
1256  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1257    return EmitGlobalConstantVector(V, AddrSpace, *this);
1258
1259  if (isa<ConstantPointerNull>(CV)) {
1260    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1261    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1262    return;
1263  }
1264
1265  // Otherwise, it must be a ConstantExpr.  Emit the data directive, then emit
1266  // the expression value.
1267  switch (TM.getTargetData()->getTypeAllocSize(CV->getType())) {
1268  case 0: return;
1269  case 1: O << MAI->getData8bitsDirective(AddrSpace); break;
1270  case 2: O << MAI->getData16bitsDirective(AddrSpace); break;
1271  case 4: O << MAI->getData32bitsDirective(AddrSpace); break;
1272  case 8:
1273    if (const char *Dir = MAI->getData64bitsDirective(AddrSpace)) {
1274      O << Dir;
1275      break;
1276    }
1277    // FALL THROUGH.
1278  default:
1279    llvm_unreachable("Target cannot handle given data directive width!");
1280    return;
1281  }
1282
1283  EmitConstantValueOnly(CV);
1284  O << '\n';
1285}
1286
1287void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1288  // Target doesn't support this yet!
1289  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1290}
1291
1292/// PrintSpecial - Print information related to the specified machine instr
1293/// that is independent of the operand, and may be independent of the instr
1294/// itself.  This can be useful for portably encoding the comment character
1295/// or other bits of target-specific knowledge into the asmstrings.  The
1296/// syntax used is ${:comment}.  Targets can override this to add support
1297/// for their own strange codes.
1298void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1299  if (!strcmp(Code, "private")) {
1300    O << MAI->getPrivateGlobalPrefix();
1301  } else if (!strcmp(Code, "comment")) {
1302    if (VerboseAsm)
1303      O << MAI->getCommentString();
1304  } else if (!strcmp(Code, "uid")) {
1305    // Comparing the address of MI isn't sufficient, because machineinstrs may
1306    // be allocated to the same address across functions.
1307    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1308
1309    // If this is a new LastFn instruction, bump the counter.
1310    if (LastMI != MI || LastFn != ThisF) {
1311      ++Counter;
1312      LastMI = MI;
1313      LastFn = ThisF;
1314    }
1315    O << Counter;
1316  } else {
1317    std::string msg;
1318    raw_string_ostream Msg(msg);
1319    Msg << "Unknown special formatter '" << Code
1320         << "' for machine instr: " << *MI;
1321    llvm_report_error(Msg.str());
1322  }
1323}
1324
1325/// processDebugLoc - Processes the debug information of each machine
1326/// instruction's DebugLoc.
1327void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1328                                 bool BeforePrintingInsn) {
1329  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1330      || !DW->ShouldEmitDwarfDebug())
1331    return;
1332  DebugLoc DL = MI->getDebugLoc();
1333  if (DL.isUnknown())
1334    return;
1335  DILocation CurDLT = MF->getDILocation(DL);
1336  if (CurDLT.getScope().isNull())
1337    return;
1338
1339  if (!BeforePrintingInsn) {
1340    // After printing instruction
1341    DW->EndScope(MI);
1342  } else if (CurDLT.getNode() != PrevDLT) {
1343    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1344                                      CurDLT.getColumnNumber(),
1345                                      CurDLT.getScope().getNode());
1346    printLabel(L);
1347    O << '\n';
1348    DW->BeginScope(MI, L);
1349    PrevDLT = CurDLT.getNode();
1350  }
1351}
1352
1353
1354/// printInlineAsm - This method formats and prints the specified machine
1355/// instruction that is an inline asm.
1356void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1357  unsigned NumOperands = MI->getNumOperands();
1358
1359  // Count the number of register definitions.
1360  unsigned NumDefs = 0;
1361  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1362       ++NumDefs)
1363    assert(NumDefs != NumOperands-1 && "No asm string?");
1364
1365  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1366
1367  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1368  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1369
1370  O << '\t';
1371
1372  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1373  // These are useful to see where empty asm's wound up.
1374  if (AsmStr[0] == 0) {
1375    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1376    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1377    return;
1378  }
1379
1380  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1381
1382  // The variant of the current asmprinter.
1383  int AsmPrinterVariant = MAI->getAssemblerDialect();
1384
1385  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1386  const char *LastEmitted = AsmStr; // One past the last character emitted.
1387
1388  while (*LastEmitted) {
1389    switch (*LastEmitted) {
1390    default: {
1391      // Not a special case, emit the string section literally.
1392      const char *LiteralEnd = LastEmitted+1;
1393      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1394             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1395        ++LiteralEnd;
1396      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1397        O.write(LastEmitted, LiteralEnd-LastEmitted);
1398      LastEmitted = LiteralEnd;
1399      break;
1400    }
1401    case '\n':
1402      ++LastEmitted;   // Consume newline character.
1403      O << '\n';       // Indent code with newline.
1404      break;
1405    case '$': {
1406      ++LastEmitted;   // Consume '$' character.
1407      bool Done = true;
1408
1409      // Handle escapes.
1410      switch (*LastEmitted) {
1411      default: Done = false; break;
1412      case '$':     // $$ -> $
1413        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1414          O << '$';
1415        ++LastEmitted;  // Consume second '$' character.
1416        break;
1417      case '(':             // $( -> same as GCC's { character.
1418        ++LastEmitted;      // Consume '(' character.
1419        if (CurVariant != -1) {
1420          llvm_report_error("Nested variants found in inline asm string: '"
1421                            + std::string(AsmStr) + "'");
1422        }
1423        CurVariant = 0;     // We're in the first variant now.
1424        break;
1425      case '|':
1426        ++LastEmitted;  // consume '|' character.
1427        if (CurVariant == -1)
1428          O << '|';       // this is gcc's behavior for | outside a variant
1429        else
1430          ++CurVariant;   // We're in the next variant.
1431        break;
1432      case ')':         // $) -> same as GCC's } char.
1433        ++LastEmitted;  // consume ')' character.
1434        if (CurVariant == -1)
1435          O << '}';     // this is gcc's behavior for } outside a variant
1436        else
1437          CurVariant = -1;
1438        break;
1439      }
1440      if (Done) break;
1441
1442      bool HasCurlyBraces = false;
1443      if (*LastEmitted == '{') {     // ${variable}
1444        ++LastEmitted;               // Consume '{' character.
1445        HasCurlyBraces = true;
1446      }
1447
1448      // If we have ${:foo}, then this is not a real operand reference, it is a
1449      // "magic" string reference, just like in .td files.  Arrange to call
1450      // PrintSpecial.
1451      if (HasCurlyBraces && *LastEmitted == ':') {
1452        ++LastEmitted;
1453        const char *StrStart = LastEmitted;
1454        const char *StrEnd = strchr(StrStart, '}');
1455        if (StrEnd == 0) {
1456          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1457                            + std::string(AsmStr) + "'");
1458        }
1459
1460        std::string Val(StrStart, StrEnd);
1461        PrintSpecial(MI, Val.c_str());
1462        LastEmitted = StrEnd+1;
1463        break;
1464      }
1465
1466      const char *IDStart = LastEmitted;
1467      char *IDEnd;
1468      errno = 0;
1469      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1470      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1471        llvm_report_error("Bad $ operand number in inline asm string: '"
1472                          + std::string(AsmStr) + "'");
1473      }
1474      LastEmitted = IDEnd;
1475
1476      char Modifier[2] = { 0, 0 };
1477
1478      if (HasCurlyBraces) {
1479        // If we have curly braces, check for a modifier character.  This
1480        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1481        if (*LastEmitted == ':') {
1482          ++LastEmitted;    // Consume ':' character.
1483          if (*LastEmitted == 0) {
1484            llvm_report_error("Bad ${:} expression in inline asm string: '"
1485                              + std::string(AsmStr) + "'");
1486          }
1487
1488          Modifier[0] = *LastEmitted;
1489          ++LastEmitted;    // Consume modifier character.
1490        }
1491
1492        if (*LastEmitted != '}') {
1493          llvm_report_error("Bad ${} expression in inline asm string: '"
1494                            + std::string(AsmStr) + "'");
1495        }
1496        ++LastEmitted;    // Consume '}' character.
1497      }
1498
1499      if ((unsigned)Val >= NumOperands-1) {
1500        llvm_report_error("Invalid $ operand number in inline asm string: '"
1501                          + std::string(AsmStr) + "'");
1502      }
1503
1504      // Okay, we finally have a value number.  Ask the target to print this
1505      // operand!
1506      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1507        unsigned OpNo = 1;
1508
1509        bool Error = false;
1510
1511        // Scan to find the machine operand number for the operand.
1512        for (; Val; --Val) {
1513          if (OpNo >= MI->getNumOperands()) break;
1514          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1515          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1516        }
1517
1518        if (OpNo >= MI->getNumOperands()) {
1519          Error = true;
1520        } else {
1521          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1522          ++OpNo;  // Skip over the ID number.
1523
1524          if (Modifier[0] == 'l')  // labels are target independent
1525            O << *GetMBBSymbol(MI->getOperand(OpNo).getMBB()->getNumber());
1526          else {
1527            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1528            if ((OpFlags & 7) == 4) {
1529              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1530                                                Modifier[0] ? Modifier : 0);
1531            } else {
1532              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1533                                          Modifier[0] ? Modifier : 0);
1534            }
1535          }
1536        }
1537        if (Error) {
1538          std::string msg;
1539          raw_string_ostream Msg(msg);
1540          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1541          MI->print(Msg);
1542          llvm_report_error(Msg.str());
1543        }
1544      }
1545      break;
1546    }
1547    }
1548  }
1549  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1550}
1551
1552/// printImplicitDef - This method prints the specified machine instruction
1553/// that is an implicit def.
1554void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1555  if (!VerboseAsm) return;
1556  O.PadToColumn(MAI->getCommentColumn());
1557  O << MAI->getCommentString() << " implicit-def: "
1558    << TRI->getName(MI->getOperand(0).getReg());
1559}
1560
1561void AsmPrinter::printKill(const MachineInstr *MI) const {
1562  if (!VerboseAsm) return;
1563  O.PadToColumn(MAI->getCommentColumn());
1564  O << MAI->getCommentString() << " kill:";
1565  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1566    const MachineOperand &op = MI->getOperand(n);
1567    assert(op.isReg() && "KILL instruction must have only register operands");
1568    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1569  }
1570}
1571
1572/// printLabel - This method prints a local label used by debug and
1573/// exception handling tables.
1574void AsmPrinter::printLabel(const MachineInstr *MI) const {
1575  printLabel(MI->getOperand(0).getImm());
1576}
1577
1578void AsmPrinter::printLabel(unsigned Id) const {
1579  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1580}
1581
1582/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1583/// instruction, using the specified assembler variant.  Targets should
1584/// override this to format as appropriate.
1585bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1586                                 unsigned AsmVariant, const char *ExtraCode) {
1587  // Target doesn't support this yet!
1588  return true;
1589}
1590
1591bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1592                                       unsigned AsmVariant,
1593                                       const char *ExtraCode) {
1594  // Target doesn't support this yet!
1595  return true;
1596}
1597
1598MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1599                                            const char *Suffix) const {
1600  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1601}
1602
1603MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1604                                            const BasicBlock *BB,
1605                                            const char *Suffix) const {
1606  assert(BB->hasName() &&
1607         "Address of anonymous basic block not supported yet!");
1608
1609  // This code must use the function name itself, and not the function number,
1610  // since it must be possible to generate the label name from within other
1611  // functions.
1612  SmallString<60> FnName;
1613  Mang->getNameWithPrefix(FnName, F, false);
1614
1615  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1616  SmallString<60> NameResult;
1617  Mang->getNameWithPrefix(NameResult,
1618                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1619                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1620                          Mangler::Private);
1621
1622  return OutContext.GetOrCreateSymbol(NameResult.str());
1623}
1624
1625MCSymbol *AsmPrinter::GetMBBSymbol(unsigned MBBID) const {
1626  SmallString<60> Name;
1627  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "BB"
1628    << getFunctionNumber() << '_' << MBBID;
1629
1630  return OutContext.GetOrCreateSymbol(Name.str());
1631}
1632
1633/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1634/// value.
1635MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1636  SmallString<60> NameStr;
1637  Mang->getNameWithPrefix(NameStr, GV, false);
1638  return OutContext.GetOrCreateSymbol(NameStr.str());
1639}
1640
1641/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1642/// global value name as its base, with the specified suffix, and where the
1643/// symbol is forced to have private linkage if ForcePrivate is true.
1644MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1645                                                   StringRef Suffix,
1646                                                   bool ForcePrivate) const {
1647  SmallString<60> NameStr;
1648  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1649  NameStr.append(Suffix.begin(), Suffix.end());
1650  return OutContext.GetOrCreateSymbol(NameStr.str());
1651}
1652
1653/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1654/// ExternalSymbol.
1655MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1656  SmallString<60> NameStr;
1657  Mang->getNameWithPrefix(NameStr, Sym);
1658  return OutContext.GetOrCreateSymbol(NameStr.str());
1659}
1660
1661
1662/// EmitBasicBlockStart - This method prints the label for the specified
1663/// MachineBasicBlock, an alignment (if present) and a comment describing
1664/// it if appropriate.
1665void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1666  // Emit an alignment directive for this block, if needed.
1667  if (unsigned Align = MBB->getAlignment())
1668    EmitAlignment(Log2_32(Align));
1669
1670  // If the block has its address taken, emit a special label to satisfy
1671  // references to the block. This is done so that we don't need to
1672  // remember the number of this label, and so that we can make
1673  // forward references to labels without knowing what their numbers
1674  // will be.
1675  if (MBB->hasAddressTaken()) {
1676    const BasicBlock *BB = MBB->getBasicBlock();
1677    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1678    if (VerboseAsm) {
1679      O.PadToColumn(MAI->getCommentColumn());
1680      O << MAI->getCommentString() << " Address Taken" << '\n';
1681    }
1682  }
1683
1684  // Print the main label for the block.
1685  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1686    if (VerboseAsm)
1687      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1688  } else {
1689    OutStreamer.EmitLabel(GetMBBSymbol(MBB->getNumber()));
1690  }
1691
1692  // Print some comments to accompany the label.
1693  if (VerboseAsm) {
1694    if (const BasicBlock *BB = MBB->getBasicBlock())
1695      if (BB->hasName()) {
1696        O.PadToColumn(MAI->getCommentColumn());
1697        O << MAI->getCommentString() << ' ';
1698        WriteAsOperand(O, BB, /*PrintType=*/false);
1699      }
1700
1701    EmitComments(*MBB);
1702    O << '\n';
1703  }
1704}
1705
1706/// printPICJumpTableSetLabel - This method prints a set label for the
1707/// specified MachineBasicBlock for a jumptable entry.
1708void AsmPrinter::printPICJumpTableSetLabel(unsigned uid,
1709                                           const MachineBasicBlock *MBB) const {
1710  if (!MAI->getSetDirective())
1711    return;
1712
1713  O << MAI->getSetDirective() << ' ' << MAI->getPrivateGlobalPrefix()
1714    << getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ','
1715    << *GetMBBSymbol(MBB->getNumber())
1716    << '-' << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
1717    << '_' << uid << '\n';
1718}
1719
1720void AsmPrinter::printPICJumpTableSetLabel(unsigned uid, unsigned uid2,
1721                                           const MachineBasicBlock *MBB) const {
1722  if (!MAI->getSetDirective())
1723    return;
1724
1725  O << MAI->getSetDirective() << ' ' << MAI->getPrivateGlobalPrefix()
1726    << getFunctionNumber() << '_' << uid << '_' << uid2
1727    << "_set_" << MBB->getNumber() << ','
1728    << *GetMBBSymbol(MBB->getNumber())
1729    << '-' << MAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
1730    << '_' << uid << '_' << uid2 << '\n';
1731}
1732
1733void AsmPrinter::printVisibility(const MCSymbol *Sym,
1734                                 unsigned Visibility) const {
1735  if (Visibility == GlobalValue::HiddenVisibility) {
1736    if (const char *Directive = MAI->getHiddenDirective())
1737      O << Directive << *Sym << '\n';
1738  } else if (Visibility == GlobalValue::ProtectedVisibility) {
1739    if (const char *Directive = MAI->getProtectedDirective())
1740      O << Directive << *Sym << '\n';
1741  }
1742}
1743
1744void AsmPrinter::printOffset(int64_t Offset) const {
1745  if (Offset > 0)
1746    O << '+' << Offset;
1747  else if (Offset < 0)
1748    O << Offset;
1749}
1750
1751GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1752  if (!S->usesMetadata())
1753    return 0;
1754
1755  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1756  if (GCPI != GCMetadataPrinters.end())
1757    return GCPI->second;
1758
1759  const char *Name = S->getName().c_str();
1760
1761  for (GCMetadataPrinterRegistry::iterator
1762         I = GCMetadataPrinterRegistry::begin(),
1763         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1764    if (strcmp(Name, I->getName()) == 0) {
1765      GCMetadataPrinter *GMP = I->instantiate();
1766      GMP->S = S;
1767      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1768      return GMP;
1769    }
1770
1771  errs() << "no GCMetadataPrinter registered for GC: " << Name << "\n";
1772  llvm_unreachable(0);
1773}
1774
1775/// EmitComments - Pretty-print comments for instructions
1776void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1777  if (!VerboseAsm)
1778    return;
1779
1780  bool Newline = false;
1781
1782  if (!MI.getDebugLoc().isUnknown()) {
1783    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1784
1785    // Print source line info.
1786    O.PadToColumn(MAI->getCommentColumn());
1787    O << MAI->getCommentString() << ' ';
1788    DIScope Scope = DLT.getScope();
1789    // Omit the directory, because it's likely to be long and uninteresting.
1790    if (!Scope.isNull())
1791      O << Scope.getFilename();
1792    else
1793      O << "<unknown>";
1794    O << ':' << DLT.getLineNumber();
1795    if (DLT.getColumnNumber() != 0)
1796      O << ':' << DLT.getColumnNumber();
1797    Newline = true;
1798  }
1799
1800  // Check for spills and reloads
1801  int FI;
1802
1803  const MachineFrameInfo *FrameInfo =
1804    MI.getParent()->getParent()->getFrameInfo();
1805
1806  // We assume a single instruction only has a spill or reload, not
1807  // both.
1808  const MachineMemOperand *MMO;
1809  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1810    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1811      MMO = *MI.memoperands_begin();
1812      if (Newline) O << '\n';
1813      O.PadToColumn(MAI->getCommentColumn());
1814      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload";
1815      Newline = true;
1816    }
1817  }
1818  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1819    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1820      if (Newline) O << '\n';
1821      O.PadToColumn(MAI->getCommentColumn());
1822      O << MAI->getCommentString() << ' '
1823        << MMO->getSize() << "-byte Folded Reload";
1824      Newline = true;
1825    }
1826  }
1827  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1828    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1829      MMO = *MI.memoperands_begin();
1830      if (Newline) O << '\n';
1831      O.PadToColumn(MAI->getCommentColumn());
1832      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill";
1833      Newline = true;
1834    }
1835  }
1836  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1837    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1838      if (Newline) O << '\n';
1839      O.PadToColumn(MAI->getCommentColumn());
1840      O << MAI->getCommentString() << ' '
1841        << MMO->getSize() << "-byte Folded Spill";
1842      Newline = true;
1843    }
1844  }
1845
1846  // Check for spill-induced copies
1847  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1848  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1849                                      SrcSubIdx, DstSubIdx)) {
1850    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1851      if (Newline) O << '\n';
1852      O.PadToColumn(MAI->getCommentColumn());
1853      O << MAI->getCommentString() << " Reload Reuse";
1854    }
1855  }
1856}
1857
1858/// PrintChildLoopComment - Print comments about child loops within
1859/// the loop for this basic block, with nesting.
1860///
1861static void PrintChildLoopComment(formatted_raw_ostream &O,
1862                                  const MachineLoop *loop,
1863                                  const MCAsmInfo *MAI,
1864                                  int FunctionNumber) {
1865  // Add child loop information
1866  for(MachineLoop::iterator cl = loop->begin(),
1867        clend = loop->end();
1868      cl != clend;
1869      ++cl) {
1870    MachineBasicBlock *Header = (*cl)->getHeader();
1871    assert(Header && "No header for loop");
1872
1873    O << '\n';
1874    O.PadToColumn(MAI->getCommentColumn());
1875
1876    O << MAI->getCommentString();
1877    O.indent(((*cl)->getLoopDepth()-1)*2)
1878      << " Child Loop BB" << FunctionNumber << "_"
1879      << Header->getNumber() << " Depth " << (*cl)->getLoopDepth();
1880
1881    PrintChildLoopComment(O, *cl, MAI, FunctionNumber);
1882  }
1883}
1884
1885/// EmitComments - Pretty-print comments for basic blocks
1886void AsmPrinter::EmitComments(const MachineBasicBlock &MBB) const {
1887  if (VerboseAsm) {
1888    // Add loop depth information
1889    const MachineLoop *loop = LI->getLoopFor(&MBB);
1890
1891    if (loop) {
1892      // Print a newline after bb# annotation.
1893      O << "\n";
1894      O.PadToColumn(MAI->getCommentColumn());
1895      O << MAI->getCommentString() << " Loop Depth " << loop->getLoopDepth()
1896        << '\n';
1897
1898      O.PadToColumn(MAI->getCommentColumn());
1899
1900      MachineBasicBlock *Header = loop->getHeader();
1901      assert(Header && "No header for loop");
1902
1903      if (Header == &MBB) {
1904        O << MAI->getCommentString() << " Loop Header";
1905        PrintChildLoopComment(O, loop, MAI, getFunctionNumber());
1906      }
1907      else {
1908        O << MAI->getCommentString() << " Loop Header is BB"
1909          << getFunctionNumber() << "_" << loop->getHeader()->getNumber();
1910      }
1911
1912      if (loop->empty()) {
1913        O << '\n';
1914        O.PadToColumn(MAI->getCommentColumn());
1915        O << MAI->getCommentString() << " Inner Loop";
1916      }
1917
1918      // Add parent loop information
1919      for (const MachineLoop *CurLoop = loop->getParentLoop();
1920           CurLoop;
1921           CurLoop = CurLoop->getParentLoop()) {
1922        MachineBasicBlock *Header = CurLoop->getHeader();
1923        assert(Header && "No header for loop");
1924
1925        O << '\n';
1926        O.PadToColumn(MAI->getCommentColumn());
1927        O << MAI->getCommentString();
1928        O.indent((CurLoop->getLoopDepth()-1)*2)
1929          << " Inside Loop BB" << getFunctionNumber() << "_"
1930          << Header->getNumber() << " Depth " << CurLoop->getLoopDepth();
1931      }
1932    }
1933  }
1934}
1935