AsmPrinter.cpp revision 28761cf9ba65a2c97ebb02aa10c4a5485d255358 
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AsmPrinter class.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "asm-printer"
15#include "llvm/CodeGen/AsmPrinter.h"
16#include "llvm/Assembly/Writer.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constants.h"
19#include "llvm/Module.h"
20#include "llvm/CodeGen/DwarfWriter.h"
21#include "llvm/CodeGen/GCMetadataPrinter.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineFunction.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineLoopInfo.h"
27#include "llvm/CodeGen/MachineModuleInfo.h"
28#include "llvm/Analysis/DebugInfo.h"
29#include "llvm/MC/MCContext.h"
30#include "llvm/MC/MCExpr.h"
31#include "llvm/MC/MCInst.h"
32#include "llvm/MC/MCSection.h"
33#include "llvm/MC/MCStreamer.h"
34#include "llvm/MC/MCSymbol.h"
35#include "llvm/MC/MCAsmInfo.h"
36#include "llvm/Target/Mangler.h"
37#include "llvm/Target/TargetData.h"
38#include "llvm/Target/TargetInstrInfo.h"
39#include "llvm/Target/TargetLowering.h"
40#include "llvm/Target/TargetLoweringObjectFile.h"
41#include "llvm/Target/TargetOptions.h"
42#include "llvm/Target/TargetRegisterInfo.h"
43#include "llvm/ADT/SmallPtrSet.h"
44#include "llvm/ADT/SmallString.h"
45#include "llvm/ADT/Statistic.h"
46#include "llvm/Support/CommandLine.h"
47#include "llvm/Support/Debug.h"
48#include "llvm/Support/ErrorHandling.h"
49#include "llvm/Support/Format.h"
50#include "llvm/Support/FormattedStream.h"
51#include <cerrno>
52using namespace llvm;
53
54STATISTIC(EmittedInsts, "Number of machine instrs printed");
55
56char AsmPrinter::ID = 0;
57AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
58                       const MCAsmInfo *T, bool VerboseAsm)
59  : MachineFunctionPass(&ID), O(o),
60    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
61
62    OutContext(*new MCContext()),
63    // FIXME: Pass instprinter to streamer.
64    OutStreamer(*createAsmStreamer(OutContext, O, *T,
65                                   TM.getTargetData()->isLittleEndian(),
66                                   VerboseAsm, 0)),
67
68    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
69  DW = 0; MMI = 0;
70  this->VerboseAsm = VerboseAsm;
71}
72
73AsmPrinter::~AsmPrinter() {
74  for (gcp_iterator I = GCMetadataPrinters.begin(),
75                    E = GCMetadataPrinters.end(); I != E; ++I)
76    delete I->second;
77
78  delete &OutStreamer;
79  delete &OutContext;
80}
81
82/// getFunctionNumber - Return a unique ID for the current function.
83///
84unsigned AsmPrinter::getFunctionNumber() const {
85  return MF->getFunctionNumber();
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  // 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  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
145void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
146  switch ((GlobalValue::LinkageTypes)Linkage) {
147  case GlobalValue::CommonLinkage:
148  case GlobalValue::LinkOnceAnyLinkage:
149  case GlobalValue::LinkOnceODRLinkage:
150  case GlobalValue::WeakAnyLinkage:
151  case GlobalValue::WeakODRLinkage:
152  case GlobalValue::LinkerPrivateLinkage:
153    if (MAI->getWeakDefDirective() != 0) {
154      // .globl _foo
155      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
156      // .weak_definition _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
158    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
159      // .globl _foo
160      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
161      // FIXME: linkonce should be a section attribute, handled by COFF Section
162      // assignment.
163      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
164      // .linkonce discard
165      // FIXME: It would be nice to use .linkonce samesize for non-common
166      // globals.
167      O << LinkOnce;
168    } else {
169      // .weak _foo
170      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
171    }
172    break;
173  case GlobalValue::DLLExportLinkage:
174  case GlobalValue::AppendingLinkage:
175    // FIXME: appending linkage variables should go into a section of
176    // their name or something.  For now, just emit them as external.
177  case GlobalValue::ExternalLinkage:
178    // If external or appending, declare as a global symbol.
179    // .globl _foo
180    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
181    break;
182  case GlobalValue::PrivateLinkage:
183  case GlobalValue::InternalLinkage:
184    break;
185  default:
186    llvm_unreachable("Unknown linkage type!");
187  }
188}
189
190
191/// EmitGlobalVariable - Emit the specified global variable to the .s file.
192void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
193  if (!GV->hasInitializer())   // External globals require no code.
194    return;
195
196  // Check to see if this is a special global used by LLVM, if so, emit it.
197  if (EmitSpecialLLVMGlobal(GV))
198    return;
199
200  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
201  EmitVisibility(GVSym, GV->getVisibility());
202
203  if (MAI->hasDotTypeDotSizeDirective())
204    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
205
206  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
207
208  const TargetData *TD = TM.getTargetData();
209  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
210  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
211
212  // Handle common and BSS local symbols (.lcomm).
213  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
214    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
215
216    if (VerboseAsm) {
217      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
218                     /*PrintType=*/false, GV->getParent());
219      OutStreamer.GetCommentOS() << '\n';
220    }
221
222    // Handle common symbols.
223    if (GVKind.isCommon()) {
224      // .comm _foo, 42, 4
225      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
226      return;
227    }
228
229    // Handle local BSS symbols.
230    if (MAI->hasMachoZeroFillDirective()) {
231      const MCSection *TheSection =
232        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
233      // .zerofill __DATA, __bss, _foo, 400, 5
234      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
235      return;
236    }
237
238    if (MAI->hasLCOMMDirective()) {
239      // .lcomm _foo, 42
240      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
241      return;
242    }
243
244    // .local _foo
245    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
246    // .comm _foo, 42, 4
247    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
248    return;
249  }
250
251  const MCSection *TheSection =
252    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
253
254  // Handle the zerofill directive on darwin, which is a special form of BSS
255  // emission.
256  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
257    // .globl _foo
258    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
259    // .zerofill __DATA, __common, _foo, 400, 5
260    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
261    return;
262  }
263
264  OutStreamer.SwitchSection(TheSection);
265
266  EmitLinkage(GV->getLinkage(), GVSym);
267  EmitAlignment(AlignLog, GV);
268
269  if (VerboseAsm) {
270    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
271                   /*PrintType=*/false, GV->getParent());
272    OutStreamer.GetCommentOS() << '\n';
273  }
274  OutStreamer.EmitLabel(GVSym);
275
276  EmitGlobalConstant(GV->getInitializer());
277
278  if (MAI->hasDotTypeDotSizeDirective())
279    // .size foo, 42
280    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
281
282  OutStreamer.AddBlankLine();
283}
284
285/// EmitFunctionHeader - This method emits the header for the current
286/// function.
287void AsmPrinter::EmitFunctionHeader() {
288  // Print out constants referenced by the function
289  EmitConstantPool();
290
291  // Print the 'header' of function.
292  const Function *F = MF->getFunction();
293
294  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
295  EmitVisibility(CurrentFnSym, F->getVisibility());
296
297  EmitLinkage(F->getLinkage(), CurrentFnSym);
298  EmitAlignment(MF->getAlignment(), F);
299
300  if (MAI->hasDotTypeDotSizeDirective())
301    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
302
303  if (VerboseAsm) {
304    WriteAsOperand(OutStreamer.GetCommentOS(), F,
305                   /*PrintType=*/false, F->getParent());
306    OutStreamer.GetCommentOS() << '\n';
307  }
308
309  // Emit the CurrentFnSym.  This is is a virtual function to allow targets to
310  // do their wild and crazy things as required.
311  EmitFunctionEntryLabel();
312
313  // Add some workaround for linkonce linkage on Cygwin\MinGW.
314  if (MAI->getLinkOnceDirective() != 0 &&
315      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
316    // FIXME: What is this?
317    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
318
319  // Emit pre-function debug and/or EH information.
320  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
321    DW->BeginFunction(MF);
322}
323
324/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
325/// function.  This can be overridden by targets as required to do custom stuff.
326void AsmPrinter::EmitFunctionEntryLabel() {
327  OutStreamer.EmitLabel(CurrentFnSym);
328}
329
330
331/// EmitFunctionBody - This method emits the body and trailer for a
332/// function.
333void AsmPrinter::EmitFunctionBody() {
334  // Emit target-specific gunk before the function body.
335  EmitFunctionBodyStart();
336
337  // Print out code for the function.
338  bool HasAnyRealCode = false;
339  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
340       I != E; ++I) {
341    // Print a label for the basic block.
342    EmitBasicBlockStart(I);
343    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
344         II != IE; ++II) {
345      // Print the assembly for the instruction.
346      if (!II->isLabel())
347        HasAnyRealCode = true;
348
349      ++EmittedInsts;
350
351      // FIXME: Clean up processDebugLoc.
352      processDebugLoc(II, true);
353
354      EmitInstruction(II);
355
356      if (VerboseAsm)
357        EmitComments(*II);
358      O << '\n';
359
360      // FIXME: Clean up processDebugLoc.
361      processDebugLoc(II, false);
362    }
363  }
364
365  // If the function is empty and the object file uses .subsections_via_symbols,
366  // then we need to emit *something* to the function body to prevent the
367  // labels from collapsing together.  Just emit a 0 byte.
368  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
369    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
370
371  // Emit target-specific gunk after the function body.
372  EmitFunctionBodyEnd();
373
374  if (MAI->hasDotTypeDotSizeDirective())
375    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
376
377  // Emit post-function debug information.
378  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
379    DW->EndFunction(MF);
380
381  // Print out jump tables referenced by the function.
382  EmitJumpTableInfo();
383}
384
385
386bool AsmPrinter::doFinalization(Module &M) {
387  // Emit global variables.
388  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
389       I != E; ++I)
390    EmitGlobalVariable(I);
391
392  // Emit final debug information.
393  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
394    DW->EndModule();
395
396  // If the target wants to know about weak references, print them all.
397  if (MAI->getWeakRefDirective()) {
398    // FIXME: This is not lazy, it would be nice to only print weak references
399    // to stuff that is actually used.  Note that doing so would require targets
400    // to notice uses in operands (due to constant exprs etc).  This should
401    // happen with the MC stuff eventually.
402
403    // Print out module-level global variables here.
404    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
405         I != E; ++I) {
406      if (!I->hasExternalWeakLinkage()) continue;
407      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
408                                      MCSA_WeakReference);
409    }
410
411    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
412      if (!I->hasExternalWeakLinkage()) continue;
413      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
414                                      MCSA_WeakReference);
415    }
416  }
417
418  if (MAI->hasSetDirective()) {
419    OutStreamer.AddBlankLine();
420    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
421         I != E; ++I) {
422      MCSymbol *Name = GetGlobalValueSymbol(I);
423
424      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
425      MCSymbol *Target = GetGlobalValueSymbol(GV);
426
427      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
428        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
429      else if (I->hasWeakLinkage())
430        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
431      else
432        assert(I->hasLocalLinkage() && "Invalid alias linkage");
433
434      EmitVisibility(Name, I->getVisibility());
435
436      // Emit the directives as assignments aka .set:
437      OutStreamer.EmitAssignment(Name,
438                                 MCSymbolRefExpr::Create(Target, OutContext));
439    }
440  }
441
442  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
443  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
444  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
445    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
446      MP->finishAssembly(O, *this, *MAI);
447
448  // If we don't have any trampolines, then we don't require stack memory
449  // to be executable. Some targets have a directive to declare this.
450  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
451  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
452    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
453      OutStreamer.SwitchSection(S);
454
455  // Allow the target to emit any magic that it wants at the end of the file,
456  // after everything else has gone out.
457  EmitEndOfAsmFile(M);
458
459  delete Mang; Mang = 0;
460  DW = 0; MMI = 0;
461
462  OutStreamer.Finish();
463  return false;
464}
465
466void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
467  this->MF = &MF;
468  // Get the function symbol.
469  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
470
471  if (VerboseAsm)
472    LI = &getAnalysis<MachineLoopInfo>();
473}
474
475namespace {
476  // SectionCPs - Keep track the alignment, constpool entries per Section.
477  struct SectionCPs {
478    const MCSection *S;
479    unsigned Alignment;
480    SmallVector<unsigned, 4> CPEs;
481    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
482  };
483}
484
485/// EmitConstantPool - Print to the current output stream assembly
486/// representations of the constants in the constant pool MCP. This is
487/// used to print out constants which have been "spilled to memory" by
488/// the code generator.
489///
490void AsmPrinter::EmitConstantPool() {
491  const MachineConstantPool *MCP = MF->getConstantPool();
492  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
493  if (CP.empty()) return;
494
495  // Calculate sections for constant pool entries. We collect entries to go into
496  // the same section together to reduce amount of section switch statements.
497  SmallVector<SectionCPs, 4> CPSections;
498  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
499    const MachineConstantPoolEntry &CPE = CP[i];
500    unsigned Align = CPE.getAlignment();
501
502    SectionKind Kind;
503    switch (CPE.getRelocationInfo()) {
504    default: llvm_unreachable("Unknown section kind");
505    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
506    case 1:
507      Kind = SectionKind::getReadOnlyWithRelLocal();
508      break;
509    case 0:
510    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
511    case 4:  Kind = SectionKind::getMergeableConst4(); break;
512    case 8:  Kind = SectionKind::getMergeableConst8(); break;
513    case 16: Kind = SectionKind::getMergeableConst16();break;
514    default: Kind = SectionKind::getMergeableConst(); break;
515    }
516    }
517
518    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
519
520    // The number of sections are small, just do a linear search from the
521    // last section to the first.
522    bool Found = false;
523    unsigned SecIdx = CPSections.size();
524    while (SecIdx != 0) {
525      if (CPSections[--SecIdx].S == S) {
526        Found = true;
527        break;
528      }
529    }
530    if (!Found) {
531      SecIdx = CPSections.size();
532      CPSections.push_back(SectionCPs(S, Align));
533    }
534
535    if (Align > CPSections[SecIdx].Alignment)
536      CPSections[SecIdx].Alignment = Align;
537    CPSections[SecIdx].CPEs.push_back(i);
538  }
539
540  // Now print stuff into the calculated sections.
541  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
542    OutStreamer.SwitchSection(CPSections[i].S);
543    EmitAlignment(Log2_32(CPSections[i].Alignment));
544
545    unsigned Offset = 0;
546    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
547      unsigned CPI = CPSections[i].CPEs[j];
548      MachineConstantPoolEntry CPE = CP[CPI];
549
550      // Emit inter-object padding for alignment.
551      unsigned AlignMask = CPE.getAlignment() - 1;
552      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
553      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
554
555      const Type *Ty = CPE.getType();
556      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
557
558      // Emit the label with a comment on it.
559      if (VerboseAsm) {
560        OutStreamer.GetCommentOS() << "constant pool ";
561        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
562                          MF->getFunction()->getParent());
563        OutStreamer.GetCommentOS() << '\n';
564      }
565      OutStreamer.EmitLabel(GetCPISymbol(CPI));
566
567      if (CPE.isMachineConstantPoolEntry())
568        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
569      else
570        EmitGlobalConstant(CPE.Val.ConstVal);
571    }
572  }
573}
574
575/// EmitJumpTableInfo - Print assembly representations of the jump tables used
576/// by the current function to the current output stream.
577///
578void AsmPrinter::EmitJumpTableInfo() {
579  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
580  if (MJTI == 0) return;
581  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
582  if (JT.empty()) return;
583
584  // Pick the directive to use to print the jump table entries, and switch to
585  // the appropriate section.
586  const Function *F = MF->getFunction();
587  bool JTInDiffSection = false;
588  if (// In PIC mode, we need to emit the jump table to the same section as the
589      // function body itself, otherwise the label differences won't make sense.
590      // FIXME: Need a better predicate for this: what about custom entries?
591      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
592      // We should also do if the section name is NULL or function is declared
593      // in discardable section
594      // FIXME: this isn't the right predicate, should be based on the MCSection
595      // for the function.
596      F->isWeakForLinker()) {
597    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
598  } else {
599    // Otherwise, drop it in the readonly section.
600    const MCSection *ReadOnlySection =
601      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
602    OutStreamer.SwitchSection(ReadOnlySection);
603    JTInDiffSection = true;
604  }
605
606  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
607
608  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
609    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
610
611    // If this jump table was deleted, ignore it.
612    if (JTBBs.empty()) continue;
613
614    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
615    // .set directive for each unique entry.  This reduces the number of
616    // relocations the assembler will generate for the jump table.
617    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
618        MAI->hasSetDirective()) {
619      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
620      const TargetLowering *TLI = TM.getTargetLowering();
621      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
622      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
623        const MachineBasicBlock *MBB = JTBBs[ii];
624        if (!EmittedSets.insert(MBB)) continue;
625
626        // .set LJTSet, LBB32-base
627        const MCExpr *LHS =
628          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
629        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
630                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
631      }
632    }
633
634    // On some targets (e.g. Darwin) we want to emit two consequtive labels
635    // before each jump table.  The first label is never referenced, but tells
636    // the assembler and linker the extents of the jump table object.  The
637    // second label is actually referenced by the code.
638    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
639      // FIXME: This doesn't have to have any specific name, just any randomly
640      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
641      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
642
643    OutStreamer.EmitLabel(GetJTISymbol(JTI));
644
645    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
646      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
647  }
648}
649
650/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
651/// current stream.
652void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
653                                    const MachineBasicBlock *MBB,
654                                    unsigned UID) const {
655  const MCExpr *Value = 0;
656  switch (MJTI->getEntryKind()) {
657  case MachineJumpTableInfo::EK_Custom32:
658    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
659                                                              OutContext);
660    break;
661  case MachineJumpTableInfo::EK_BlockAddress:
662    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
663    //     .word LBB123
664    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
665    break;
666  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
667    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
668    // with a relocation as gp-relative, e.g.:
669    //     .gprel32 LBB123
670    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
671    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
672    return;
673  }
674
675  case MachineJumpTableInfo::EK_LabelDifference32: {
676    // EK_LabelDifference32 - Each entry is the address of the block minus
677    // the address of the jump table.  This is used for PIC jump tables where
678    // gprel32 is not supported.  e.g.:
679    //      .word LBB123 - LJTI1_2
680    // If the .set directive is supported, this is emitted as:
681    //      .set L4_5_set_123, LBB123 - LJTI1_2
682    //      .word L4_5_set_123
683
684    // If we have emitted set directives for the jump table entries, print
685    // them rather than the entries themselves.  If we're emitting PIC, then
686    // emit the table entries as differences between two text section labels.
687    if (MAI->hasSetDirective()) {
688      // If we used .set, reference the .set's symbol.
689      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
690                                      OutContext);
691      break;
692    }
693    // Otherwise, use the difference as the jump table entry.
694    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
695    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
696    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
697    break;
698  }
699  }
700
701  assert(Value && "Unknown entry kind!");
702
703  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
704  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
705}
706
707
708/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
709/// special global used by LLVM.  If so, emit it and return true, otherwise
710/// do nothing and return false.
711bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
712  if (GV->getName() == "llvm.used") {
713    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
714      EmitLLVMUsedList(GV->getInitializer());
715    return true;
716  }
717
718  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
719  if (GV->getSection() == "llvm.metadata" ||
720      GV->hasAvailableExternallyLinkage())
721    return true;
722
723  if (!GV->hasAppendingLinkage()) return false;
724
725  assert(GV->hasInitializer() && "Not a special LLVM global!");
726
727  const TargetData *TD = TM.getTargetData();
728  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
729  if (GV->getName() == "llvm.global_ctors") {
730    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
731    EmitAlignment(Align, 0);
732    EmitXXStructorList(GV->getInitializer());
733
734    if (TM.getRelocationModel() == Reloc::Static &&
735        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
736      StringRef Sym(".constructors_used");
737      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
738                                      MCSA_Reference);
739    }
740    return true;
741  }
742
743  if (GV->getName() == "llvm.global_dtors") {
744    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
745    EmitAlignment(Align, 0);
746    EmitXXStructorList(GV->getInitializer());
747
748    if (TM.getRelocationModel() == Reloc::Static &&
749        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
750      StringRef Sym(".destructors_used");
751      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
752                                      MCSA_Reference);
753    }
754    return true;
755  }
756
757  return false;
758}
759
760/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
761/// global in the specified llvm.used list for which emitUsedDirectiveFor
762/// is true, as being used with this directive.
763void AsmPrinter::EmitLLVMUsedList(Constant *List) {
764  // Should be an array of 'i8*'.
765  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
766  if (InitList == 0) return;
767
768  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
769    const GlobalValue *GV =
770      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
771    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
772      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
773                                      MCSA_NoDeadStrip);
774  }
775}
776
777/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
778/// function pointers, ignoring the init priority.
779void AsmPrinter::EmitXXStructorList(Constant *List) {
780  // Should be an array of '{ int, void ()* }' structs.  The first value is the
781  // init priority, which we ignore.
782  if (!isa<ConstantArray>(List)) return;
783  ConstantArray *InitList = cast<ConstantArray>(List);
784  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
785    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
786      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
787
788      if (CS->getOperand(1)->isNullValue())
789        return;  // Found a null terminator, exit printing.
790      // Emit the function pointer.
791      EmitGlobalConstant(CS->getOperand(1));
792    }
793}
794
795//===--------------------------------------------------------------------===//
796// Emission and print routines
797//
798
799/// EmitInt8 - Emit a byte directive and value.
800///
801void AsmPrinter::EmitInt8(int Value) const {
802  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
803}
804
805/// EmitInt16 - Emit a short directive and value.
806///
807void AsmPrinter::EmitInt16(int Value) const {
808  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
809}
810
811/// EmitInt32 - Emit a long directive and value.
812///
813void AsmPrinter::EmitInt32(int Value) const {
814  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
815}
816
817/// EmitInt64 - Emit a long long directive and value.
818///
819void AsmPrinter::EmitInt64(uint64_t Value) const {
820  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
821}
822
823//===----------------------------------------------------------------------===//
824
825// EmitAlignment - Emit an alignment directive to the specified power of
826// two boundary.  For example, if you pass in 3 here, you will get an 8
827// byte alignment.  If a global value is specified, and if that global has
828// an explicit alignment requested, it will unconditionally override the
829// alignment request.  However, if ForcedAlignBits is specified, this value
830// has final say: the ultimate alignment will be the max of ForcedAlignBits
831// and the alignment computed with NumBits and the global.
832//
833// The algorithm is:
834//     Align = NumBits;
835//     if (GV && GV->hasalignment) Align = GV->getalignment();
836//     Align = std::max(Align, ForcedAlignBits);
837//
838void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
839                               unsigned ForcedAlignBits,
840                               bool UseFillExpr) const {
841  if (GV && GV->getAlignment())
842    NumBits = Log2_32(GV->getAlignment());
843  NumBits = std::max(NumBits, ForcedAlignBits);
844
845  if (NumBits == 0) return;   // No need to emit alignment.
846
847  unsigned FillValue = 0;
848  if (getCurrentSection()->getKind().isText())
849    FillValue = MAI->getTextAlignFillValue();
850
851  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
852}
853
854/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
855///
856static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
857  MCContext &Ctx = AP.OutContext;
858
859  if (CV->isNullValue() || isa<UndefValue>(CV))
860    return MCConstantExpr::Create(0, Ctx);
861
862  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
863    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
864
865  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
866    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
867  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
868    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
869
870  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
871  if (CE == 0) {
872    llvm_unreachable("Unknown constant value to lower!");
873    return MCConstantExpr::Create(0, Ctx);
874  }
875
876  switch (CE->getOpcode()) {
877  case Instruction::ZExt:
878  case Instruction::SExt:
879  case Instruction::FPTrunc:
880  case Instruction::FPExt:
881  case Instruction::UIToFP:
882  case Instruction::SIToFP:
883  case Instruction::FPToUI:
884  case Instruction::FPToSI:
885  default: llvm_unreachable("FIXME: Don't support this constant cast expr");
886  case Instruction::GetElementPtr: {
887    const TargetData &TD = *AP.TM.getTargetData();
888    // Generate a symbolic expression for the byte address
889    const Constant *PtrVal = CE->getOperand(0);
890    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
891    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
892                                         IdxVec.size());
893
894    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
895    if (Offset == 0)
896      return Base;
897
898    // Truncate/sext the offset to the pointer size.
899    if (TD.getPointerSizeInBits() != 64) {
900      int SExtAmount = 64-TD.getPointerSizeInBits();
901      Offset = (Offset << SExtAmount) >> SExtAmount;
902    }
903
904    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
905                                   Ctx);
906  }
907
908  case Instruction::Trunc:
909    // We emit the value and depend on the assembler to truncate the generated
910    // expression properly.  This is important for differences between
911    // blockaddress labels.  Since the two labels are in the same function, it
912    // is reasonable to treat their delta as a 32-bit value.
913    // FALL THROUGH.
914  case Instruction::BitCast:
915    return LowerConstant(CE->getOperand(0), AP);
916
917  case Instruction::IntToPtr: {
918    const TargetData &TD = *AP.TM.getTargetData();
919    // Handle casts to pointers by changing them into casts to the appropriate
920    // integer type.  This promotes constant folding and simplifies this code.
921    Constant *Op = CE->getOperand(0);
922    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
923                                      false/*ZExt*/);
924    return LowerConstant(Op, AP);
925  }
926
927  case Instruction::PtrToInt: {
928    const TargetData &TD = *AP.TM.getTargetData();
929    // Support only foldable casts to/from pointers that can be eliminated by
930    // changing the pointer to the appropriately sized integer type.
931    Constant *Op = CE->getOperand(0);
932    const Type *Ty = CE->getType();
933
934    const MCExpr *OpExpr = LowerConstant(Op, AP);
935
936    // We can emit the pointer value into this slot if the slot is an
937    // integer slot equal to the size of the pointer.
938    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
939      return OpExpr;
940
941    // Otherwise the pointer is smaller than the resultant integer, mask off
942    // the high bits so we are sure to get a proper truncation if the input is
943    // a constant expr.
944    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
945    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
946    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
947  }
948
949  case Instruction::Add:
950  case Instruction::Sub:
951  case Instruction::And:
952  case Instruction::Or:
953  case Instruction::Xor: {
954    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
955    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
956    switch (CE->getOpcode()) {
957    default: llvm_unreachable("Unknown binary operator constant cast expr");
958    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
959    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
960    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
961    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
962    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
963    }
964  }
965  }
966}
967
968static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
969                                    AsmPrinter &AP) {
970  if (AddrSpace != 0 || !CA->isString()) {
971    // Not a string.  Print the values in successive locations
972    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
973      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
974    return;
975  }
976
977  // Otherwise, it can be emitted as .ascii.
978  SmallVector<char, 128> TmpVec;
979  TmpVec.reserve(CA->getNumOperands());
980  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
981    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
982
983  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
984}
985
986static void EmitGlobalConstantVector(const ConstantVector *CV,
987                                     unsigned AddrSpace, AsmPrinter &AP) {
988  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
989    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
990}
991
992static void EmitGlobalConstantStruct(const ConstantStruct *CS,
993                                     unsigned AddrSpace, AsmPrinter &AP) {
994  // Print the fields in successive locations. Pad to align if needed!
995  const TargetData *TD = AP.TM.getTargetData();
996  unsigned Size = TD->getTypeAllocSize(CS->getType());
997  const StructLayout *Layout = TD->getStructLayout(CS->getType());
998  uint64_t SizeSoFar = 0;
999  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1000    const Constant *Field = CS->getOperand(i);
1001
1002    // Check if padding is needed and insert one or more 0s.
1003    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1004    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1005                        - Layout->getElementOffset(i)) - FieldSize;
1006    SizeSoFar += FieldSize + PadSize;
1007
1008    // Now print the actual field value.
1009    AP.EmitGlobalConstant(Field, AddrSpace);
1010
1011    // Insert padding - this may include padding to increase the size of the
1012    // current field up to the ABI size (if the struct is not packed) as well
1013    // as padding to ensure that the next field starts at the right offset.
1014    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1015  }
1016  assert(SizeSoFar == Layout->getSizeInBytes() &&
1017         "Layout of constant struct may be incorrect!");
1018}
1019
1020static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1021                                 AsmPrinter &AP) {
1022  // FP Constants are printed as integer constants to avoid losing
1023  // precision.
1024  if (CFP->getType()->isDoubleTy()) {
1025    if (AP.VerboseAsm) {
1026      double Val = CFP->getValueAPF().convertToDouble();
1027      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1028    }
1029
1030    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1031    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1032    return;
1033  }
1034
1035  if (CFP->getType()->isFloatTy()) {
1036    if (AP.VerboseAsm) {
1037      float Val = CFP->getValueAPF().convertToFloat();
1038      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1039    }
1040    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1041    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1042    return;
1043  }
1044
1045  if (CFP->getType()->isX86_FP80Ty()) {
1046    // all long double variants are printed as hex
1047    // api needed to prevent premature destruction
1048    APInt API = CFP->getValueAPF().bitcastToAPInt();
1049    const uint64_t *p = API.getRawData();
1050    if (AP.VerboseAsm) {
1051      // Convert to double so we can print the approximate val as a comment.
1052      APFloat DoubleVal = CFP->getValueAPF();
1053      bool ignored;
1054      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1055                        &ignored);
1056      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1057        << DoubleVal.convertToDouble() << '\n';
1058    }
1059
1060    if (AP.TM.getTargetData()->isBigEndian()) {
1061      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1062      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1063    } else {
1064      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1065      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1066    }
1067
1068    // Emit the tail padding for the long double.
1069    const TargetData &TD = *AP.TM.getTargetData();
1070    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1071                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1072    return;
1073  }
1074
1075  assert(CFP->getType()->isPPC_FP128Ty() &&
1076         "Floating point constant type not handled");
1077  // All long double variants are printed as hex api needed to prevent
1078  // premature destruction.
1079  APInt API = CFP->getValueAPF().bitcastToAPInt();
1080  const uint64_t *p = API.getRawData();
1081  if (AP.TM.getTargetData()->isBigEndian()) {
1082    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1083    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1084  } else {
1085    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1086    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1087  }
1088}
1089
1090static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1091                                       unsigned AddrSpace, AsmPrinter &AP) {
1092  const TargetData *TD = AP.TM.getTargetData();
1093  unsigned BitWidth = CI->getBitWidth();
1094  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1095
1096  // We don't expect assemblers to support integer data directives
1097  // for more than 64 bits, so we emit the data in at most 64-bit
1098  // quantities at a time.
1099  const uint64_t *RawData = CI->getValue().getRawData();
1100  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1101    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1102    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1103  }
1104}
1105
1106/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1107void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1108  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1109    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1110    return OutStreamer.EmitZeros(Size, AddrSpace);
1111  }
1112
1113  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1114    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1115    switch (Size) {
1116    case 1:
1117    case 2:
1118    case 4:
1119    case 8:
1120      if (VerboseAsm)
1121        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1122      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1123      return;
1124    default:
1125      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1126      return;
1127    }
1128  }
1129
1130  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1131    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1132
1133  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1134    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1135
1136  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1137    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1138
1139  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1140    return EmitGlobalConstantVector(V, AddrSpace, *this);
1141
1142  if (isa<ConstantPointerNull>(CV)) {
1143    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1144    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1145    return;
1146  }
1147
1148  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1149  // thread the streamer with EmitValue.
1150  OutStreamer.EmitValue(LowerConstant(CV, *this),
1151                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1152                        AddrSpace);
1153}
1154
1155void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1156  // Target doesn't support this yet!
1157  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1158}
1159
1160/// PrintSpecial - Print information related to the specified machine instr
1161/// that is independent of the operand, and may be independent of the instr
1162/// itself.  This can be useful for portably encoding the comment character
1163/// or other bits of target-specific knowledge into the asmstrings.  The
1164/// syntax used is ${:comment}.  Targets can override this to add support
1165/// for their own strange codes.
1166void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1167  if (!strcmp(Code, "private")) {
1168    O << MAI->getPrivateGlobalPrefix();
1169  } else if (!strcmp(Code, "comment")) {
1170    if (VerboseAsm)
1171      O << MAI->getCommentString();
1172  } else if (!strcmp(Code, "uid")) {
1173    // Comparing the address of MI isn't sufficient, because machineinstrs may
1174    // be allocated to the same address across functions.
1175    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1176
1177    // If this is a new LastFn instruction, bump the counter.
1178    if (LastMI != MI || LastFn != ThisF) {
1179      ++Counter;
1180      LastMI = MI;
1181      LastFn = ThisF;
1182    }
1183    O << Counter;
1184  } else {
1185    std::string msg;
1186    raw_string_ostream Msg(msg);
1187    Msg << "Unknown special formatter '" << Code
1188         << "' for machine instr: " << *MI;
1189    llvm_report_error(Msg.str());
1190  }
1191}
1192
1193/// processDebugLoc - Processes the debug information of each machine
1194/// instruction's DebugLoc.
1195void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1196                                 bool BeforePrintingInsn) {
1197  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1198      || !DW->ShouldEmitDwarfDebug())
1199    return;
1200  DebugLoc DL = MI->getDebugLoc();
1201  if (DL.isUnknown())
1202    return;
1203  DILocation CurDLT = MF->getDILocation(DL);
1204  if (CurDLT.getScope().isNull())
1205    return;
1206
1207  if (!BeforePrintingInsn) {
1208    // After printing instruction
1209    DW->EndScope(MI);
1210  } else if (CurDLT.getNode() != PrevDLT) {
1211    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1212                                      CurDLT.getColumnNumber(),
1213                                      CurDLT.getScope().getNode());
1214    printLabel(L);
1215    O << '\n';
1216    DW->BeginScope(MI, L);
1217    PrevDLT = CurDLT.getNode();
1218  }
1219}
1220
1221
1222/// printInlineAsm - This method formats and prints the specified machine
1223/// instruction that is an inline asm.
1224void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1225  unsigned NumOperands = MI->getNumOperands();
1226
1227  // Count the number of register definitions.
1228  unsigned NumDefs = 0;
1229  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1230       ++NumDefs)
1231    assert(NumDefs != NumOperands-1 && "No asm string?");
1232
1233  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1234
1235  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1236  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1237
1238  O << '\t';
1239
1240  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1241  // These are useful to see where empty asm's wound up.
1242  if (AsmStr[0] == 0) {
1243    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1244    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1245    return;
1246  }
1247
1248  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1249
1250  // The variant of the current asmprinter.
1251  int AsmPrinterVariant = MAI->getAssemblerDialect();
1252
1253  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1254  const char *LastEmitted = AsmStr; // One past the last character emitted.
1255
1256  while (*LastEmitted) {
1257    switch (*LastEmitted) {
1258    default: {
1259      // Not a special case, emit the string section literally.
1260      const char *LiteralEnd = LastEmitted+1;
1261      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1262             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1263        ++LiteralEnd;
1264      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1265        O.write(LastEmitted, LiteralEnd-LastEmitted);
1266      LastEmitted = LiteralEnd;
1267      break;
1268    }
1269    case '\n':
1270      ++LastEmitted;   // Consume newline character.
1271      O << '\n';       // Indent code with newline.
1272      break;
1273    case '$': {
1274      ++LastEmitted;   // Consume '$' character.
1275      bool Done = true;
1276
1277      // Handle escapes.
1278      switch (*LastEmitted) {
1279      default: Done = false; break;
1280      case '$':     // $$ -> $
1281        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1282          O << '$';
1283        ++LastEmitted;  // Consume second '$' character.
1284        break;
1285      case '(':             // $( -> same as GCC's { character.
1286        ++LastEmitted;      // Consume '(' character.
1287        if (CurVariant != -1) {
1288          llvm_report_error("Nested variants found in inline asm string: '"
1289                            + std::string(AsmStr) + "'");
1290        }
1291        CurVariant = 0;     // We're in the first variant now.
1292        break;
1293      case '|':
1294        ++LastEmitted;  // consume '|' character.
1295        if (CurVariant == -1)
1296          O << '|';       // this is gcc's behavior for | outside a variant
1297        else
1298          ++CurVariant;   // We're in the next variant.
1299        break;
1300      case ')':         // $) -> same as GCC's } char.
1301        ++LastEmitted;  // consume ')' character.
1302        if (CurVariant == -1)
1303          O << '}';     // this is gcc's behavior for } outside a variant
1304        else
1305          CurVariant = -1;
1306        break;
1307      }
1308      if (Done) break;
1309
1310      bool HasCurlyBraces = false;
1311      if (*LastEmitted == '{') {     // ${variable}
1312        ++LastEmitted;               // Consume '{' character.
1313        HasCurlyBraces = true;
1314      }
1315
1316      // If we have ${:foo}, then this is not a real operand reference, it is a
1317      // "magic" string reference, just like in .td files.  Arrange to call
1318      // PrintSpecial.
1319      if (HasCurlyBraces && *LastEmitted == ':') {
1320        ++LastEmitted;
1321        const char *StrStart = LastEmitted;
1322        const char *StrEnd = strchr(StrStart, '}');
1323        if (StrEnd == 0) {
1324          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1325                            + std::string(AsmStr) + "'");
1326        }
1327
1328        std::string Val(StrStart, StrEnd);
1329        PrintSpecial(MI, Val.c_str());
1330        LastEmitted = StrEnd+1;
1331        break;
1332      }
1333
1334      const char *IDStart = LastEmitted;
1335      char *IDEnd;
1336      errno = 0;
1337      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1338      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1339        llvm_report_error("Bad $ operand number in inline asm string: '"
1340                          + std::string(AsmStr) + "'");
1341      }
1342      LastEmitted = IDEnd;
1343
1344      char Modifier[2] = { 0, 0 };
1345
1346      if (HasCurlyBraces) {
1347        // If we have curly braces, check for a modifier character.  This
1348        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1349        if (*LastEmitted == ':') {
1350          ++LastEmitted;    // Consume ':' character.
1351          if (*LastEmitted == 0) {
1352            llvm_report_error("Bad ${:} expression in inline asm string: '"
1353                              + std::string(AsmStr) + "'");
1354          }
1355
1356          Modifier[0] = *LastEmitted;
1357          ++LastEmitted;    // Consume modifier character.
1358        }
1359
1360        if (*LastEmitted != '}') {
1361          llvm_report_error("Bad ${} expression in inline asm string: '"
1362                            + std::string(AsmStr) + "'");
1363        }
1364        ++LastEmitted;    // Consume '}' character.
1365      }
1366
1367      if ((unsigned)Val >= NumOperands-1) {
1368        llvm_report_error("Invalid $ operand number in inline asm string: '"
1369                          + std::string(AsmStr) + "'");
1370      }
1371
1372      // Okay, we finally have a value number.  Ask the target to print this
1373      // operand!
1374      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1375        unsigned OpNo = 1;
1376
1377        bool Error = false;
1378
1379        // Scan to find the machine operand number for the operand.
1380        for (; Val; --Val) {
1381          if (OpNo >= MI->getNumOperands()) break;
1382          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1383          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1384        }
1385
1386        if (OpNo >= MI->getNumOperands()) {
1387          Error = true;
1388        } else {
1389          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1390          ++OpNo;  // Skip over the ID number.
1391
1392          if (Modifier[0] == 'l')  // labels are target independent
1393            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1394          else {
1395            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1396            if ((OpFlags & 7) == 4) {
1397              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1398                                                Modifier[0] ? Modifier : 0);
1399            } else {
1400              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1401                                          Modifier[0] ? Modifier : 0);
1402            }
1403          }
1404        }
1405        if (Error) {
1406          std::string msg;
1407          raw_string_ostream Msg(msg);
1408          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1409          MI->print(Msg);
1410          llvm_report_error(Msg.str());
1411        }
1412      }
1413      break;
1414    }
1415    }
1416  }
1417  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1418}
1419
1420/// printImplicitDef - This method prints the specified machine instruction
1421/// that is an implicit def.
1422void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1423  if (!VerboseAsm) return;
1424  O.PadToColumn(MAI->getCommentColumn());
1425  O << MAI->getCommentString() << " implicit-def: "
1426    << TRI->getName(MI->getOperand(0).getReg());
1427}
1428
1429void AsmPrinter::printKill(const MachineInstr *MI) const {
1430  if (!VerboseAsm) return;
1431  O.PadToColumn(MAI->getCommentColumn());
1432  O << MAI->getCommentString() << " kill:";
1433  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1434    const MachineOperand &op = MI->getOperand(n);
1435    assert(op.isReg() && "KILL instruction must have only register operands");
1436    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1437  }
1438}
1439
1440/// printLabel - This method prints a local label used by debug and
1441/// exception handling tables.
1442void AsmPrinter::printLabel(const MachineInstr *MI) const {
1443  printLabel(MI->getOperand(0).getImm());
1444}
1445
1446void AsmPrinter::printLabel(unsigned Id) const {
1447  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1448}
1449
1450/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1451/// instruction, using the specified assembler variant.  Targets should
1452/// override this to format as appropriate.
1453bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1454                                 unsigned AsmVariant, const char *ExtraCode) {
1455  // Target doesn't support this yet!
1456  return true;
1457}
1458
1459bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1460                                       unsigned AsmVariant,
1461                                       const char *ExtraCode) {
1462  // Target doesn't support this yet!
1463  return true;
1464}
1465
1466MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1467                                            const char *Suffix) const {
1468  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1469}
1470
1471MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1472                                            const BasicBlock *BB,
1473                                            const char *Suffix) const {
1474  assert(BB->hasName() &&
1475         "Address of anonymous basic block not supported yet!");
1476
1477  // This code must use the function name itself, and not the function number,
1478  // since it must be possible to generate the label name from within other
1479  // functions.
1480  SmallString<60> FnName;
1481  Mang->getNameWithPrefix(FnName, F, false);
1482
1483  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1484  SmallString<60> NameResult;
1485  Mang->getNameWithPrefix(NameResult,
1486                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1487                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1488                          Mangler::Private);
1489
1490  return OutContext.GetOrCreateSymbol(NameResult.str());
1491}
1492
1493/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1494MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1495  SmallString<60> Name;
1496  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1497    << getFunctionNumber() << '_' << CPID;
1498  return OutContext.GetOrCreateSymbol(Name.str());
1499}
1500
1501/// GetJTISymbol - Return the symbol for the specified jump table entry.
1502MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1503  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1504}
1505
1506/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1507/// FIXME: privatize to AsmPrinter.
1508MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1509  SmallString<60> Name;
1510  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1511    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1512  return OutContext.GetOrCreateSymbol(Name.str());
1513}
1514
1515/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1516/// value.
1517MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1518  SmallString<60> NameStr;
1519  Mang->getNameWithPrefix(NameStr, GV, false);
1520  return OutContext.GetOrCreateSymbol(NameStr.str());
1521}
1522
1523/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1524/// global value name as its base, with the specified suffix, and where the
1525/// symbol is forced to have private linkage if ForcePrivate is true.
1526MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1527                                                   StringRef Suffix,
1528                                                   bool ForcePrivate) const {
1529  SmallString<60> NameStr;
1530  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1531  NameStr.append(Suffix.begin(), Suffix.end());
1532  return OutContext.GetOrCreateSymbol(NameStr.str());
1533}
1534
1535/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1536/// ExternalSymbol.
1537MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1538  SmallString<60> NameStr;
1539  Mang->getNameWithPrefix(NameStr, Sym);
1540  return OutContext.GetOrCreateSymbol(NameStr.str());
1541}
1542
1543
1544
1545/// PrintParentLoopComment - Print comments about parent loops of this one.
1546static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1547                                   unsigned FunctionNumber) {
1548  if (Loop == 0) return;
1549  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1550  OS.indent(Loop->getLoopDepth()*2)
1551    << "Parent Loop BB" << FunctionNumber << "_"
1552    << Loop->getHeader()->getNumber()
1553    << " Depth=" << Loop->getLoopDepth() << '\n';
1554}
1555
1556
1557/// PrintChildLoopComment - Print comments about child loops within
1558/// the loop for this basic block, with nesting.
1559static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1560                                  unsigned FunctionNumber) {
1561  // Add child loop information
1562  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1563    OS.indent((*CL)->getLoopDepth()*2)
1564      << "Child Loop BB" << FunctionNumber << "_"
1565      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1566      << '\n';
1567    PrintChildLoopComment(OS, *CL, FunctionNumber);
1568  }
1569}
1570
1571/// EmitComments - Pretty-print comments for basic blocks.
1572static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1573                                        const MachineLoopInfo *LI,
1574                                        const AsmPrinter &AP) {
1575  // Add loop depth information
1576  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1577  if (Loop == 0) return;
1578
1579  MachineBasicBlock *Header = Loop->getHeader();
1580  assert(Header && "No header for loop");
1581
1582  // If this block is not a loop header, just print out what is the loop header
1583  // and return.
1584  if (Header != &MBB) {
1585    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1586                              Twine(AP.getFunctionNumber())+"_" +
1587                              Twine(Loop->getHeader()->getNumber())+
1588                              " Depth="+Twine(Loop->getLoopDepth()));
1589    return;
1590  }
1591
1592  // Otherwise, it is a loop header.  Print out information about child and
1593  // parent loops.
1594  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1595
1596  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1597
1598  OS << "=>";
1599  OS.indent(Loop->getLoopDepth()*2-2);
1600
1601  OS << "This ";
1602  if (Loop->empty())
1603    OS << "Inner ";
1604  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1605
1606  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1607}
1608
1609
1610/// EmitBasicBlockStart - This method prints the label for the specified
1611/// MachineBasicBlock, an alignment (if present) and a comment describing
1612/// it if appropriate.
1613void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1614  // Emit an alignment directive for this block, if needed.
1615  if (unsigned Align = MBB->getAlignment())
1616    EmitAlignment(Log2_32(Align));
1617
1618  // If the block has its address taken, emit a special label to satisfy
1619  // references to the block. This is done so that we don't need to
1620  // remember the number of this label, and so that we can make
1621  // forward references to labels without knowing what their numbers
1622  // will be.
1623  if (MBB->hasAddressTaken()) {
1624    const BasicBlock *BB = MBB->getBasicBlock();
1625    if (VerboseAsm)
1626      OutStreamer.AddComment("Address Taken");
1627    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1628  }
1629
1630  // Print the main label for the block.
1631  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1632    if (VerboseAsm) {
1633      // NOTE: Want this comment at start of line.
1634      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1635      if (const BasicBlock *BB = MBB->getBasicBlock())
1636        if (BB->hasName())
1637          OutStreamer.AddComment("%" + BB->getName());
1638
1639      PrintBasicBlockLoopComments(*MBB, LI, *this);
1640      OutStreamer.AddBlankLine();
1641    }
1642  } else {
1643    if (VerboseAsm) {
1644      if (const BasicBlock *BB = MBB->getBasicBlock())
1645        if (BB->hasName())
1646          OutStreamer.AddComment("%" + BB->getName());
1647      PrintBasicBlockLoopComments(*MBB, LI, *this);
1648    }
1649
1650    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1651  }
1652}
1653
1654void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1655  MCSymbolAttr Attr = MCSA_Invalid;
1656
1657  switch (Visibility) {
1658  default: break;
1659  case GlobalValue::HiddenVisibility:
1660    Attr = MAI->getHiddenVisibilityAttr();
1661    break;
1662  case GlobalValue::ProtectedVisibility:
1663    Attr = MAI->getProtectedVisibilityAttr();
1664    break;
1665  }
1666
1667  if (Attr != MCSA_Invalid)
1668    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1669}
1670
1671void AsmPrinter::printOffset(int64_t Offset) const {
1672  if (Offset > 0)
1673    O << '+' << Offset;
1674  else if (Offset < 0)
1675    O << Offset;
1676}
1677
1678GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1679  if (!S->usesMetadata())
1680    return 0;
1681
1682  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1683  if (GCPI != GCMetadataPrinters.end())
1684    return GCPI->second;
1685
1686  const char *Name = S->getName().c_str();
1687
1688  for (GCMetadataPrinterRegistry::iterator
1689         I = GCMetadataPrinterRegistry::begin(),
1690         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1691    if (strcmp(Name, I->getName()) == 0) {
1692      GCMetadataPrinter *GMP = I->instantiate();
1693      GMP->S = S;
1694      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1695      return GMP;
1696    }
1697
1698  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1699  return 0;
1700}
1701
1702/// EmitComments - Pretty-print comments for instructions
1703void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1704  if (!VerboseAsm)
1705    return;
1706
1707  bool Newline = false;
1708
1709  if (!MI.getDebugLoc().isUnknown()) {
1710    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1711
1712    // Print source line info.
1713    O.PadToColumn(MAI->getCommentColumn());
1714    O << MAI->getCommentString() << ' ';
1715    DIScope Scope = DLT.getScope();
1716    // Omit the directory, because it's likely to be long and uninteresting.
1717    if (!Scope.isNull())
1718      O << Scope.getFilename();
1719    else
1720      O << "<unknown>";
1721    O << ':' << DLT.getLineNumber();
1722    if (DLT.getColumnNumber() != 0)
1723      O << ':' << DLT.getColumnNumber();
1724    Newline = true;
1725  }
1726
1727  // Check for spills and reloads
1728  int FI;
1729
1730  const MachineFrameInfo *FrameInfo =
1731    MI.getParent()->getParent()->getFrameInfo();
1732
1733  // We assume a single instruction only has a spill or reload, not
1734  // both.
1735  const MachineMemOperand *MMO;
1736  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1737    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1738      MMO = *MI.memoperands_begin();
1739      if (Newline) O << '\n';
1740      O.PadToColumn(MAI->getCommentColumn());
1741      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload";
1742      Newline = true;
1743    }
1744  }
1745  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1746    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1747      if (Newline) O << '\n';
1748      O.PadToColumn(MAI->getCommentColumn());
1749      O << MAI->getCommentString() << ' '
1750        << MMO->getSize() << "-byte Folded Reload";
1751      Newline = true;
1752    }
1753  }
1754  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1755    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1756      MMO = *MI.memoperands_begin();
1757      if (Newline) O << '\n';
1758      O.PadToColumn(MAI->getCommentColumn());
1759      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill";
1760      Newline = true;
1761    }
1762  }
1763  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1764    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1765      if (Newline) O << '\n';
1766      O.PadToColumn(MAI->getCommentColumn());
1767      O << MAI->getCommentString() << ' '
1768        << MMO->getSize() << "-byte Folded Spill";
1769      Newline = true;
1770    }
1771  }
1772
1773  // Check for spill-induced copies
1774  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1775  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1776                                      SrcSubIdx, DstSubIdx)) {
1777    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1778      if (Newline) O << '\n';
1779      O.PadToColumn(MAI->getCommentColumn());
1780      O << MAI->getCommentString() << " Reload Reuse";
1781    }
1782  }
1783}
1784
1785