AsmPrinter.cpp revision 9bc20ab519d47146a9716d7cff2a892da78774a6 
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/MCExpr.h"
30#include "llvm/MC/MCInst.h"
31#include "llvm/MC/MCSection.h"
32#include "llvm/MC/MCStreamer.h"
33#include "llvm/MC/MCSymbol.h"
34#include "llvm/Support/CommandLine.h"
35#include "llvm/Support/ErrorHandling.h"
36#include "llvm/Support/Format.h"
37#include "llvm/Support/FormattedStream.h"
38#include "llvm/MC/MCAsmInfo.h"
39#include "llvm/Target/Mangler.h"
40#include "llvm/Target/TargetData.h"
41#include "llvm/Target/TargetInstrInfo.h"
42#include "llvm/Target/TargetLowering.h"
43#include "llvm/Target/TargetLoweringObjectFile.h"
44#include "llvm/Target/TargetOptions.h"
45#include "llvm/Target/TargetRegisterInfo.h"
46#include "llvm/ADT/SmallPtrSet.h"
47#include "llvm/ADT/SmallString.h"
48#include <cerrno>
49using namespace llvm;
50
51static cl::opt<cl::boolOrDefault>
52AsmVerbose("asm-verbose", cl::desc("Add comments to directives."),
53           cl::init(cl::BOU_UNSET));
54
55static bool getVerboseAsm(bool VDef) {
56  switch (AsmVerbose) {
57  default:
58  case cl::BOU_UNSET: return VDef;
59  case cl::BOU_TRUE:  return true;
60  case cl::BOU_FALSE: return false;
61  }
62}
63
64char AsmPrinter::ID = 0;
65AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
66                       const MCAsmInfo *T, bool VDef)
67  : MachineFunctionPass(&ID), O(o),
68    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
69
70    OutContext(*new MCContext()),
71    // FIXME: Pass instprinter to streamer.
72    OutStreamer(*createAsmStreamer(OutContext, O, *T,
73                                   TM.getTargetData()->isLittleEndian(),
74                                   getVerboseAsm(VDef), 0)),
75
76    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
77  DW = 0; MMI = 0;
78  VerboseAsm = getVerboseAsm(VDef);
79}
80
81AsmPrinter::~AsmPrinter() {
82  for (gcp_iterator I = GCMetadataPrinters.begin(),
83                    E = GCMetadataPrinters.end(); I != E; ++I)
84    delete I->second;
85
86  delete &OutStreamer;
87  delete &OutContext;
88}
89
90/// getFunctionNumber - Return a unique ID for the current function.
91///
92unsigned AsmPrinter::getFunctionNumber() const {
93  return MF->getFunctionNumber();
94}
95
96TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
97  return TM.getTargetLowering()->getObjFileLowering();
98}
99
100/// getCurrentSection() - Return the current section we are emitting to.
101const MCSection *AsmPrinter::getCurrentSection() const {
102  return OutStreamer.getCurrentSection();
103}
104
105
106void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
107  AU.setPreservesAll();
108  MachineFunctionPass::getAnalysisUsage(AU);
109  AU.addRequired<GCModuleInfo>();
110  if (VerboseAsm)
111    AU.addRequired<MachineLoopInfo>();
112}
113
114bool AsmPrinter::doInitialization(Module &M) {
115  // Initialize TargetLoweringObjectFile.
116  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
117    .Initialize(OutContext, TM);
118
119  Mang = new Mangler(*MAI);
120
121  // Allow the target to emit any magic that it wants at the start of the file.
122  EmitStartOfAsmFile(M);
123
124  // Very minimal debug info. It is ignored if we emit actual debug info. If we
125  // don't, this at least helps the user find where a global came from.
126  if (MAI->hasSingleParameterDotFile()) {
127    // .file "foo.c"
128    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
129  }
130
131  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
132  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
133  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
134    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
135      MP->beginAssembly(O, *this, *MAI);
136
137  if (!M.getModuleInlineAsm().empty())
138    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
139      << M.getModuleInlineAsm()
140      << '\n' << MAI->getCommentString()
141      << " End of file scope inline assembly\n";
142
143  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
144  if (MMI)
145    MMI->AnalyzeModule(M);
146  DW = getAnalysisIfAvailable<DwarfWriter>();
147  if (DW)
148    DW->BeginModule(&M, MMI, O, this, MAI);
149
150  return false;
151}
152
153void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) {
154  switch ((GlobalValue::LinkageTypes)Linkage) {
155  case GlobalValue::CommonLinkage:
156  case GlobalValue::LinkOnceAnyLinkage:
157  case GlobalValue::LinkOnceODRLinkage:
158  case GlobalValue::WeakAnyLinkage:
159  case GlobalValue::WeakODRLinkage:
160  case GlobalValue::LinkerPrivateLinkage:
161    if (MAI->getWeakDefDirective() != 0) {
162      // .globl _foo
163      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
164      // .weak_definition _foo
165      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
166    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
167      // .globl _foo
168      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
169      // FIXME: linkonce should be a section attribute, handled by COFF Section
170      // assignment.
171      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
172      // .linkonce discard
173      // FIXME: It would be nice to use .linkonce samesize for non-common
174      // globals.
175      O << LinkOnce;
176    } else {
177      // .weak _foo
178      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
179    }
180    break;
181  case GlobalValue::DLLExportLinkage:
182  case GlobalValue::AppendingLinkage:
183    // FIXME: appending linkage variables should go into a section of
184    // their name or something.  For now, just emit them as external.
185  case GlobalValue::ExternalLinkage:
186    // If external or appending, declare as a global symbol.
187    // .globl _foo
188    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
189    break;
190  case GlobalValue::PrivateLinkage:
191  case GlobalValue::InternalLinkage:
192    break;
193  default:
194    llvm_unreachable("Unknown linkage type!");
195  }
196}
197
198
199/// EmitGlobalVariable - Emit the specified global variable to the .s file.
200void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
201  if (!GV->hasInitializer())   // External globals require no code.
202    return;
203
204  // Check to see if this is a special global used by LLVM, if so, emit it.
205  if (EmitSpecialLLVMGlobal(GV))
206    return;
207
208  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
209  printVisibility(GVSym, GV->getVisibility());
210
211  if (MAI->hasDotTypeDotSizeDirective())
212    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
213
214  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
215
216  const TargetData *TD = TM.getTargetData();
217  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
218  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
219
220  // Handle common and BSS local symbols (.lcomm).
221  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
222    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
223
224    if (VerboseAsm) {
225      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
226                     /*PrintType=*/false, GV->getParent());
227      OutStreamer.GetCommentOS() << '\n';
228    }
229
230    // Handle common symbols.
231    if (GVKind.isCommon()) {
232      // .comm _foo, 42, 4
233      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
234      return;
235    }
236
237    // Handle local BSS symbols.
238    if (MAI->hasMachoZeroFillDirective()) {
239      const MCSection *TheSection =
240        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
241      // .zerofill __DATA, __bss, _foo, 400, 5
242      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
243      return;
244    }
245
246    if (MAI->hasLCOMMDirective()) {
247      // .lcomm _foo, 42
248      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
249      return;
250    }
251
252    // .local _foo
253    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
254    // .comm _foo, 42, 4
255    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
256    return;
257  }
258
259  const MCSection *TheSection =
260    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
261
262  // Handle the zerofill directive on darwin, which is a special form of BSS
263  // emission.
264  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
265    // .globl _foo
266    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
267    // .zerofill __DATA, __common, _foo, 400, 5
268    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
269    return;
270  }
271
272  OutStreamer.SwitchSection(TheSection);
273
274  EmitLinkage(GV->getLinkage(), GVSym);
275  EmitAlignment(AlignLog, GV);
276
277  if (VerboseAsm) {
278    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
279                   /*PrintType=*/false, GV->getParent());
280    OutStreamer.GetCommentOS() << '\n';
281  }
282  OutStreamer.EmitLabel(GVSym);
283
284  EmitGlobalConstant(GV->getInitializer());
285
286  if (MAI->hasDotTypeDotSizeDirective())
287    // .size foo, 42
288    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
289
290  OutStreamer.AddBlankLine();
291}
292
293/// EmitFunctionHeader - This method emits the header for the current
294/// function.
295void AsmPrinter::EmitFunctionHeader() {
296  // Print out constants referenced by the function
297  EmitConstantPool(MF->getConstantPool());
298
299  // Print the 'header' of function.
300  const Function *F = MF->getFunction();
301
302  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
303  printVisibility(CurrentFnSym, F->getVisibility());
304
305  EmitLinkage(F->getLinkage(), CurrentFnSym);
306  EmitAlignment(MF->getAlignment(), F);
307
308  if (MAI->hasDotTypeDotSizeDirective())
309    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
310
311  if (VerboseAsm) {
312    WriteAsOperand(OutStreamer.GetCommentOS(), F,
313                   /*PrintType=*/false, F->getParent());
314    OutStreamer.GetCommentOS() << '\n';
315  }
316  OutStreamer.EmitLabel(CurrentFnSym);
317
318  // Add some workaround for linkonce linkage on Cygwin\MinGW.
319  if (MAI->getLinkOnceDirective() != 0 &&
320      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
321    // FIXME: What is this?
322    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
323
324  // Emit pre-function debug and/or EH information.
325  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
326    DW->BeginFunction(MF);
327}
328
329
330
331
332bool AsmPrinter::doFinalization(Module &M) {
333  // Emit global variables.
334  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
335       I != E; ++I)
336    EmitGlobalVariable(I);
337
338  // Emit final debug information.
339  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
340    DW->EndModule();
341
342  // If the target wants to know about weak references, print them all.
343  if (MAI->getWeakRefDirective()) {
344    // FIXME: This is not lazy, it would be nice to only print weak references
345    // to stuff that is actually used.  Note that doing so would require targets
346    // to notice uses in operands (due to constant exprs etc).  This should
347    // happen with the MC stuff eventually.
348
349    // Print out module-level global variables here.
350    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
351         I != E; ++I) {
352      if (!I->hasExternalWeakLinkage()) continue;
353      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
354                                      MCSA_WeakReference);
355    }
356
357    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
358      if (!I->hasExternalWeakLinkage()) continue;
359      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
360                                      MCSA_WeakReference);
361    }
362  }
363
364  if (MAI->hasSetDirective()) {
365    OutStreamer.AddBlankLine();
366    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
367         I != E; ++I) {
368      MCSymbol *Name = GetGlobalValueSymbol(I);
369
370      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
371      MCSymbol *Target = GetGlobalValueSymbol(GV);
372
373      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
374        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
375      else if (I->hasWeakLinkage())
376        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
377      else
378        assert(I->hasLocalLinkage() && "Invalid alias linkage");
379
380      printVisibility(Name, I->getVisibility());
381
382      // Emit the directives as assignments aka .set:
383      OutStreamer.EmitAssignment(Name,
384                                 MCSymbolRefExpr::Create(Target, OutContext));
385    }
386  }
387
388  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
389  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
390  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
391    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
392      MP->finishAssembly(O, *this, *MAI);
393
394  // If we don't have any trampolines, then we don't require stack memory
395  // to be executable. Some targets have a directive to declare this.
396  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
397  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
398    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
399      OutStreamer.SwitchSection(S);
400
401  // Allow the target to emit any magic that it wants at the end of the file,
402  // after everything else has gone out.
403  EmitEndOfAsmFile(M);
404
405  delete Mang; Mang = 0;
406  DW = 0; MMI = 0;
407
408  OutStreamer.Finish();
409  return false;
410}
411
412void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
413  this->MF = &MF;
414  // Get the function symbol.
415  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
416
417  if (VerboseAsm)
418    LI = &getAnalysis<MachineLoopInfo>();
419}
420
421namespace {
422  // SectionCPs - Keep track the alignment, constpool entries per Section.
423  struct SectionCPs {
424    const MCSection *S;
425    unsigned Alignment;
426    SmallVector<unsigned, 4> CPEs;
427    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
428  };
429}
430
431/// EmitConstantPool - Print to the current output stream assembly
432/// representations of the constants in the constant pool MCP. This is
433/// used to print out constants which have been "spilled to memory" by
434/// the code generator.
435///
436void AsmPrinter::EmitConstantPool(const MachineConstantPool *MCP) {
437  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
438  if (CP.empty()) return;
439
440  // Calculate sections for constant pool entries. We collect entries to go into
441  // the same section together to reduce amount of section switch statements.
442  SmallVector<SectionCPs, 4> CPSections;
443  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
444    const MachineConstantPoolEntry &CPE = CP[i];
445    unsigned Align = CPE.getAlignment();
446
447    SectionKind Kind;
448    switch (CPE.getRelocationInfo()) {
449    default: llvm_unreachable("Unknown section kind");
450    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
451    case 1:
452      Kind = SectionKind::getReadOnlyWithRelLocal();
453      break;
454    case 0:
455    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
456    case 4:  Kind = SectionKind::getMergeableConst4(); break;
457    case 8:  Kind = SectionKind::getMergeableConst8(); break;
458    case 16: Kind = SectionKind::getMergeableConst16();break;
459    default: Kind = SectionKind::getMergeableConst(); break;
460    }
461    }
462
463    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
464
465    // The number of sections are small, just do a linear search from the
466    // last section to the first.
467    bool Found = false;
468    unsigned SecIdx = CPSections.size();
469    while (SecIdx != 0) {
470      if (CPSections[--SecIdx].S == S) {
471        Found = true;
472        break;
473      }
474    }
475    if (!Found) {
476      SecIdx = CPSections.size();
477      CPSections.push_back(SectionCPs(S, Align));
478    }
479
480    if (Align > CPSections[SecIdx].Alignment)
481      CPSections[SecIdx].Alignment = Align;
482    CPSections[SecIdx].CPEs.push_back(i);
483  }
484
485  // Now print stuff into the calculated sections.
486  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
487    OutStreamer.SwitchSection(CPSections[i].S);
488    EmitAlignment(Log2_32(CPSections[i].Alignment));
489
490    unsigned Offset = 0;
491    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
492      unsigned CPI = CPSections[i].CPEs[j];
493      MachineConstantPoolEntry CPE = CP[CPI];
494
495      // Emit inter-object padding for alignment.
496      unsigned AlignMask = CPE.getAlignment() - 1;
497      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
498      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
499
500      const Type *Ty = CPE.getType();
501      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
502
503      // Emit the label with a comment on it.
504      if (VerboseAsm) {
505        OutStreamer.GetCommentOS() << "constant pool ";
506        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
507                          MF->getFunction()->getParent());
508        OutStreamer.GetCommentOS() << '\n';
509      }
510      OutStreamer.EmitLabel(GetCPISymbol(CPI));
511
512      if (CPE.isMachineConstantPoolEntry())
513        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
514      else
515        EmitGlobalConstant(CPE.Val.ConstVal);
516    }
517  }
518}
519
520/// EmitJumpTableInfo - Print assembly representations of the jump tables used
521/// by the current function to the current output stream.
522///
523void AsmPrinter::EmitJumpTableInfo(MachineFunction &MF) {
524  MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
525  if (MJTI == 0) return;
526  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
527  if (JT.empty()) return;
528
529  // Pick the directive to use to print the jump table entries, and switch to
530  // the appropriate section.
531  const Function *F = MF.getFunction();
532  bool JTInDiffSection = false;
533  if (// In PIC mode, we need to emit the jump table to the same section as the
534      // function body itself, otherwise the label differences won't make sense.
535      // FIXME: Need a better predicate for this: what about custom entries?
536      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
537      // We should also do if the section name is NULL or function is declared
538      // in discardable section
539      // FIXME: this isn't the right predicate, should be based on the MCSection
540      // for the function.
541      F->isWeakForLinker()) {
542    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang,
543                                                                    TM));
544  } else {
545    // Otherwise, drop it in the readonly section.
546    const MCSection *ReadOnlySection =
547      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
548    OutStreamer.SwitchSection(ReadOnlySection);
549    JTInDiffSection = true;
550  }
551
552  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
553
554  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
555    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
556
557    // If this jump table was deleted, ignore it.
558    if (JTBBs.empty()) continue;
559
560    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
561    // .set directive for each unique entry.  This reduces the number of
562    // relocations the assembler will generate for the jump table.
563    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
564        MAI->hasSetDirective()) {
565      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
566      const TargetLowering *TLI = TM.getTargetLowering();
567      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(&MF, JTI,
568                                                             OutContext);
569      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
570        const MachineBasicBlock *MBB = JTBBs[ii];
571        if (!EmittedSets.insert(MBB)) continue;
572
573        // .set LJTSet, LBB32-base
574        const MCExpr *LHS =
575          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
576        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
577                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
578      }
579    }
580
581    // On some targets (e.g. Darwin) we want to emit two consequtive labels
582    // before each jump table.  The first label is never referenced, but tells
583    // the assembler and linker the extents of the jump table object.  The
584    // second label is actually referenced by the code.
585    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
586      // FIXME: This doesn't have to have any specific name, just any randomly
587      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
588      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
589
590    OutStreamer.EmitLabel(GetJTISymbol(JTI));
591
592    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
593      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
594  }
595}
596
597/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
598/// current stream.
599void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
600                                    const MachineBasicBlock *MBB,
601                                    unsigned UID) const {
602  const MCExpr *Value = 0;
603  switch (MJTI->getEntryKind()) {
604  case MachineJumpTableInfo::EK_Custom32:
605    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
606                                                              OutContext);
607    break;
608  case MachineJumpTableInfo::EK_BlockAddress:
609    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
610    //     .word LBB123
611    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
612    break;
613  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
614    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
615    // with a relocation as gp-relative, e.g.:
616    //     .gprel32 LBB123
617    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
618    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
619    return;
620  }
621
622  case MachineJumpTableInfo::EK_LabelDifference32: {
623    // EK_LabelDifference32 - Each entry is the address of the block minus
624    // the address of the jump table.  This is used for PIC jump tables where
625    // gprel32 is not supported.  e.g.:
626    //      .word LBB123 - LJTI1_2
627    // If the .set directive is supported, this is emitted as:
628    //      .set L4_5_set_123, LBB123 - LJTI1_2
629    //      .word L4_5_set_123
630
631    // If we have emitted set directives for the jump table entries, print
632    // them rather than the entries themselves.  If we're emitting PIC, then
633    // emit the table entries as differences between two text section labels.
634    if (MAI->hasSetDirective()) {
635      // If we used .set, reference the .set's symbol.
636      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
637                                      OutContext);
638      break;
639    }
640    // Otherwise, use the difference as the jump table entry.
641    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
642    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
643    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
644    break;
645  }
646  }
647
648  assert(Value && "Unknown entry kind!");
649
650  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
651  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
652}
653
654
655/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
656/// special global used by LLVM.  If so, emit it and return true, otherwise
657/// do nothing and return false.
658bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
659  if (GV->getName() == "llvm.used") {
660    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
661      EmitLLVMUsedList(GV->getInitializer());
662    return true;
663  }
664
665  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
666  if (GV->getSection() == "llvm.metadata" ||
667      GV->hasAvailableExternallyLinkage())
668    return true;
669
670  if (!GV->hasAppendingLinkage()) return false;
671
672  assert(GV->hasInitializer() && "Not a special LLVM global!");
673
674  const TargetData *TD = TM.getTargetData();
675  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
676  if (GV->getName() == "llvm.global_ctors") {
677    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
678    EmitAlignment(Align, 0);
679    EmitXXStructorList(GV->getInitializer());
680
681    if (TM.getRelocationModel() == Reloc::Static &&
682        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
683      StringRef Sym(".constructors_used");
684      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
685                                      MCSA_Reference);
686    }
687    return true;
688  }
689
690  if (GV->getName() == "llvm.global_dtors") {
691    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
692    EmitAlignment(Align, 0);
693    EmitXXStructorList(GV->getInitializer());
694
695    if (TM.getRelocationModel() == Reloc::Static &&
696        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
697      StringRef Sym(".destructors_used");
698      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
699                                      MCSA_Reference);
700    }
701    return true;
702  }
703
704  return false;
705}
706
707/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
708/// global in the specified llvm.used list for which emitUsedDirectiveFor
709/// is true, as being used with this directive.
710void AsmPrinter::EmitLLVMUsedList(Constant *List) {
711  // Should be an array of 'i8*'.
712  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
713  if (InitList == 0) return;
714
715  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
716    const GlobalValue *GV =
717      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
718    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
719      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
720                                      MCSA_NoDeadStrip);
721  }
722}
723
724/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
725/// function pointers, ignoring the init priority.
726void AsmPrinter::EmitXXStructorList(Constant *List) {
727  // Should be an array of '{ int, void ()* }' structs.  The first value is the
728  // init priority, which we ignore.
729  if (!isa<ConstantArray>(List)) return;
730  ConstantArray *InitList = cast<ConstantArray>(List);
731  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
732    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
733      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
734
735      if (CS->getOperand(1)->isNullValue())
736        return;  // Found a null terminator, exit printing.
737      // Emit the function pointer.
738      EmitGlobalConstant(CS->getOperand(1));
739    }
740}
741
742//===--------------------------------------------------------------------===//
743// Emission and print routines
744//
745
746/// EmitInt8 - Emit a byte directive and value.
747///
748void AsmPrinter::EmitInt8(int Value) const {
749  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
750}
751
752/// EmitInt16 - Emit a short directive and value.
753///
754void AsmPrinter::EmitInt16(int Value) const {
755  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
756}
757
758/// EmitInt32 - Emit a long directive and value.
759///
760void AsmPrinter::EmitInt32(int Value) const {
761  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
762}
763
764/// EmitInt64 - Emit a long long directive and value.
765///
766void AsmPrinter::EmitInt64(uint64_t Value) const {
767  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
768}
769
770//===----------------------------------------------------------------------===//
771
772// EmitAlignment - Emit an alignment directive to the specified power of
773// two boundary.  For example, if you pass in 3 here, you will get an 8
774// byte alignment.  If a global value is specified, and if that global has
775// an explicit alignment requested, it will unconditionally override the
776// alignment request.  However, if ForcedAlignBits is specified, this value
777// has final say: the ultimate alignment will be the max of ForcedAlignBits
778// and the alignment computed with NumBits and the global.
779//
780// The algorithm is:
781//     Align = NumBits;
782//     if (GV && GV->hasalignment) Align = GV->getalignment();
783//     Align = std::max(Align, ForcedAlignBits);
784//
785void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
786                               unsigned ForcedAlignBits,
787                               bool UseFillExpr) const {
788  if (GV && GV->getAlignment())
789    NumBits = Log2_32(GV->getAlignment());
790  NumBits = std::max(NumBits, ForcedAlignBits);
791
792  if (NumBits == 0) return;   // No need to emit alignment.
793
794  unsigned FillValue = 0;
795  if (getCurrentSection()->getKind().isText())
796    FillValue = MAI->getTextAlignFillValue();
797
798  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
799}
800
801/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
802///
803static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
804  MCContext &Ctx = AP.OutContext;
805
806  if (CV->isNullValue() || isa<UndefValue>(CV))
807    return MCConstantExpr::Create(0, Ctx);
808
809  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
810    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
811
812  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
813    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
814  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
815    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
816
817  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
818  if (CE == 0) {
819    llvm_unreachable("Unknown constant value to lower!");
820    return MCConstantExpr::Create(0, Ctx);
821  }
822
823  switch (CE->getOpcode()) {
824  case Instruction::ZExt:
825  case Instruction::SExt:
826  case Instruction::FPTrunc:
827  case Instruction::FPExt:
828  case Instruction::UIToFP:
829  case Instruction::SIToFP:
830  case Instruction::FPToUI:
831  case Instruction::FPToSI:
832  default: llvm_unreachable("FIXME: Don't support this constant cast expr");
833  case Instruction::GetElementPtr: {
834    const TargetData &TD = *AP.TM.getTargetData();
835    // Generate a symbolic expression for the byte address
836    const Constant *PtrVal = CE->getOperand(0);
837    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
838    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
839                                         IdxVec.size());
840
841    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
842    if (Offset == 0)
843      return Base;
844
845    // Truncate/sext the offset to the pointer size.
846    if (TD.getPointerSizeInBits() != 64) {
847      int SExtAmount = 64-TD.getPointerSizeInBits();
848      Offset = (Offset << SExtAmount) >> SExtAmount;
849    }
850
851    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
852                                   Ctx);
853  }
854
855  case Instruction::Trunc:
856    // We emit the value and depend on the assembler to truncate the generated
857    // expression properly.  This is important for differences between
858    // blockaddress labels.  Since the two labels are in the same function, it
859    // is reasonable to treat their delta as a 32-bit value.
860    // FALL THROUGH.
861  case Instruction::BitCast:
862    return LowerConstant(CE->getOperand(0), AP);
863
864  case Instruction::IntToPtr: {
865    const TargetData &TD = *AP.TM.getTargetData();
866    // Handle casts to pointers by changing them into casts to the appropriate
867    // integer type.  This promotes constant folding and simplifies this code.
868    Constant *Op = CE->getOperand(0);
869    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
870                                      false/*ZExt*/);
871    return LowerConstant(Op, AP);
872  }
873
874  case Instruction::PtrToInt: {
875    const TargetData &TD = *AP.TM.getTargetData();
876    // Support only foldable casts to/from pointers that can be eliminated by
877    // changing the pointer to the appropriately sized integer type.
878    Constant *Op = CE->getOperand(0);
879    const Type *Ty = CE->getType();
880
881    const MCExpr *OpExpr = LowerConstant(Op, AP);
882
883    // We can emit the pointer value into this slot if the slot is an
884    // integer slot equal to the size of the pointer.
885    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
886      return OpExpr;
887
888    // Otherwise the pointer is smaller than the resultant integer, mask off
889    // the high bits so we are sure to get a proper truncation if the input is
890    // a constant expr.
891    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
892    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
893    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
894  }
895
896  case Instruction::Add:
897  case Instruction::Sub:
898  case Instruction::And:
899  case Instruction::Or:
900  case Instruction::Xor: {
901    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
902    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
903    switch (CE->getOpcode()) {
904    default: llvm_unreachable("Unknown binary operator constant cast expr");
905    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
906    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
907    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
908    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
909    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
910    }
911  }
912  }
913}
914
915static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
916                                    AsmPrinter &AP) {
917  if (AddrSpace != 0 || !CA->isString()) {
918    // Not a string.  Print the values in successive locations
919    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
920      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
921    return;
922  }
923
924  // Otherwise, it can be emitted as .ascii.
925  SmallVector<char, 128> TmpVec;
926  TmpVec.reserve(CA->getNumOperands());
927  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
928    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
929
930  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
931}
932
933static void EmitGlobalConstantVector(const ConstantVector *CV,
934                                     unsigned AddrSpace, AsmPrinter &AP) {
935  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
936    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
937}
938
939static void EmitGlobalConstantStruct(const ConstantStruct *CS,
940                                     unsigned AddrSpace, AsmPrinter &AP) {
941  // Print the fields in successive locations. Pad to align if needed!
942  const TargetData *TD = AP.TM.getTargetData();
943  unsigned Size = TD->getTypeAllocSize(CS->getType());
944  const StructLayout *Layout = TD->getStructLayout(CS->getType());
945  uint64_t SizeSoFar = 0;
946  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
947    const Constant *Field = CS->getOperand(i);
948
949    // Check if padding is needed and insert one or more 0s.
950    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
951    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
952                        - Layout->getElementOffset(i)) - FieldSize;
953    SizeSoFar += FieldSize + PadSize;
954
955    // Now print the actual field value.
956    AP.EmitGlobalConstant(Field, AddrSpace);
957
958    // Insert padding - this may include padding to increase the size of the
959    // current field up to the ABI size (if the struct is not packed) as well
960    // as padding to ensure that the next field starts at the right offset.
961    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
962  }
963  assert(SizeSoFar == Layout->getSizeInBytes() &&
964         "Layout of constant struct may be incorrect!");
965}
966
967static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
968                                 AsmPrinter &AP) {
969  // FP Constants are printed as integer constants to avoid losing
970  // precision.
971  if (CFP->getType()->isDoubleTy()) {
972    if (AP.VerboseAsm) {
973      double Val = CFP->getValueAPF().convertToDouble();
974      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
975    }
976
977    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
978    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
979    return;
980  }
981
982  if (CFP->getType()->isFloatTy()) {
983    if (AP.VerboseAsm) {
984      float Val = CFP->getValueAPF().convertToFloat();
985      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
986    }
987    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
988    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
989    return;
990  }
991
992  if (CFP->getType()->isX86_FP80Ty()) {
993    // all long double variants are printed as hex
994    // api needed to prevent premature destruction
995    APInt API = CFP->getValueAPF().bitcastToAPInt();
996    const uint64_t *p = API.getRawData();
997    if (AP.VerboseAsm) {
998      // Convert to double so we can print the approximate val as a comment.
999      APFloat DoubleVal = CFP->getValueAPF();
1000      bool ignored;
1001      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1002                        &ignored);
1003      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1004        << DoubleVal.convertToDouble() << '\n';
1005    }
1006
1007    if (AP.TM.getTargetData()->isBigEndian()) {
1008      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1009      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1010    } else {
1011      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1012      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1013    }
1014
1015    // Emit the tail padding for the long double.
1016    const TargetData &TD = *AP.TM.getTargetData();
1017    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1018                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1019    return;
1020  }
1021
1022  assert(CFP->getType()->isPPC_FP128Ty() &&
1023         "Floating point constant type not handled");
1024  // All long double variants are printed as hex api needed to prevent
1025  // premature destruction.
1026  APInt API = CFP->getValueAPF().bitcastToAPInt();
1027  const uint64_t *p = API.getRawData();
1028  if (AP.TM.getTargetData()->isBigEndian()) {
1029    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1030    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1031  } else {
1032    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1033    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1034  }
1035}
1036
1037static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1038                                       unsigned AddrSpace, AsmPrinter &AP) {
1039  const TargetData *TD = AP.TM.getTargetData();
1040  unsigned BitWidth = CI->getBitWidth();
1041  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1042
1043  // We don't expect assemblers to support integer data directives
1044  // for more than 64 bits, so we emit the data in at most 64-bit
1045  // quantities at a time.
1046  const uint64_t *RawData = CI->getValue().getRawData();
1047  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1048    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1049    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1050  }
1051}
1052
1053/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1054void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1055  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1056    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1057    return OutStreamer.EmitZeros(Size, AddrSpace);
1058  }
1059
1060  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1061    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1062    switch (Size) {
1063    case 1:
1064    case 2:
1065    case 4:
1066    case 8:
1067      if (VerboseAsm)
1068        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1069      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1070      return;
1071    default:
1072      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1073      return;
1074    }
1075  }
1076
1077  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1078    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1079
1080  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1081    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1082
1083  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1084    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1085
1086  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1087    return EmitGlobalConstantVector(V, AddrSpace, *this);
1088
1089  if (isa<ConstantPointerNull>(CV)) {
1090    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1091    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1092    return;
1093  }
1094
1095  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1096  // thread the streamer with EmitValue.
1097  OutStreamer.EmitValue(LowerConstant(CV, *this),
1098                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1099                        AddrSpace);
1100}
1101
1102void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1103  // Target doesn't support this yet!
1104  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1105}
1106
1107/// PrintSpecial - Print information related to the specified machine instr
1108/// that is independent of the operand, and may be independent of the instr
1109/// itself.  This can be useful for portably encoding the comment character
1110/// or other bits of target-specific knowledge into the asmstrings.  The
1111/// syntax used is ${:comment}.  Targets can override this to add support
1112/// for their own strange codes.
1113void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1114  if (!strcmp(Code, "private")) {
1115    O << MAI->getPrivateGlobalPrefix();
1116  } else if (!strcmp(Code, "comment")) {
1117    if (VerboseAsm)
1118      O << MAI->getCommentString();
1119  } else if (!strcmp(Code, "uid")) {
1120    // Comparing the address of MI isn't sufficient, because machineinstrs may
1121    // be allocated to the same address across functions.
1122    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1123
1124    // If this is a new LastFn instruction, bump the counter.
1125    if (LastMI != MI || LastFn != ThisF) {
1126      ++Counter;
1127      LastMI = MI;
1128      LastFn = ThisF;
1129    }
1130    O << Counter;
1131  } else {
1132    std::string msg;
1133    raw_string_ostream Msg(msg);
1134    Msg << "Unknown special formatter '" << Code
1135         << "' for machine instr: " << *MI;
1136    llvm_report_error(Msg.str());
1137  }
1138}
1139
1140/// processDebugLoc - Processes the debug information of each machine
1141/// instruction's DebugLoc.
1142void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1143                                 bool BeforePrintingInsn) {
1144  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1145      || !DW->ShouldEmitDwarfDebug())
1146    return;
1147  DebugLoc DL = MI->getDebugLoc();
1148  if (DL.isUnknown())
1149    return;
1150  DILocation CurDLT = MF->getDILocation(DL);
1151  if (CurDLT.getScope().isNull())
1152    return;
1153
1154  if (!BeforePrintingInsn) {
1155    // After printing instruction
1156    DW->EndScope(MI);
1157  } else if (CurDLT.getNode() != PrevDLT) {
1158    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1159                                      CurDLT.getColumnNumber(),
1160                                      CurDLT.getScope().getNode());
1161    printLabel(L);
1162    O << '\n';
1163    DW->BeginScope(MI, L);
1164    PrevDLT = CurDLT.getNode();
1165  }
1166}
1167
1168
1169/// printInlineAsm - This method formats and prints the specified machine
1170/// instruction that is an inline asm.
1171void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1172  unsigned NumOperands = MI->getNumOperands();
1173
1174  // Count the number of register definitions.
1175  unsigned NumDefs = 0;
1176  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1177       ++NumDefs)
1178    assert(NumDefs != NumOperands-1 && "No asm string?");
1179
1180  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1181
1182  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1183  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1184
1185  O << '\t';
1186
1187  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1188  // These are useful to see where empty asm's wound up.
1189  if (AsmStr[0] == 0) {
1190    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1191    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1192    return;
1193  }
1194
1195  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1196
1197  // The variant of the current asmprinter.
1198  int AsmPrinterVariant = MAI->getAssemblerDialect();
1199
1200  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1201  const char *LastEmitted = AsmStr; // One past the last character emitted.
1202
1203  while (*LastEmitted) {
1204    switch (*LastEmitted) {
1205    default: {
1206      // Not a special case, emit the string section literally.
1207      const char *LiteralEnd = LastEmitted+1;
1208      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1209             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1210        ++LiteralEnd;
1211      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1212        O.write(LastEmitted, LiteralEnd-LastEmitted);
1213      LastEmitted = LiteralEnd;
1214      break;
1215    }
1216    case '\n':
1217      ++LastEmitted;   // Consume newline character.
1218      O << '\n';       // Indent code with newline.
1219      break;
1220    case '$': {
1221      ++LastEmitted;   // Consume '$' character.
1222      bool Done = true;
1223
1224      // Handle escapes.
1225      switch (*LastEmitted) {
1226      default: Done = false; break;
1227      case '$':     // $$ -> $
1228        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1229          O << '$';
1230        ++LastEmitted;  // Consume second '$' character.
1231        break;
1232      case '(':             // $( -> same as GCC's { character.
1233        ++LastEmitted;      // Consume '(' character.
1234        if (CurVariant != -1) {
1235          llvm_report_error("Nested variants found in inline asm string: '"
1236                            + std::string(AsmStr) + "'");
1237        }
1238        CurVariant = 0;     // We're in the first variant now.
1239        break;
1240      case '|':
1241        ++LastEmitted;  // consume '|' character.
1242        if (CurVariant == -1)
1243          O << '|';       // this is gcc's behavior for | outside a variant
1244        else
1245          ++CurVariant;   // We're in the next variant.
1246        break;
1247      case ')':         // $) -> same as GCC's } char.
1248        ++LastEmitted;  // consume ')' character.
1249        if (CurVariant == -1)
1250          O << '}';     // this is gcc's behavior for } outside a variant
1251        else
1252          CurVariant = -1;
1253        break;
1254      }
1255      if (Done) break;
1256
1257      bool HasCurlyBraces = false;
1258      if (*LastEmitted == '{') {     // ${variable}
1259        ++LastEmitted;               // Consume '{' character.
1260        HasCurlyBraces = true;
1261      }
1262
1263      // If we have ${:foo}, then this is not a real operand reference, it is a
1264      // "magic" string reference, just like in .td files.  Arrange to call
1265      // PrintSpecial.
1266      if (HasCurlyBraces && *LastEmitted == ':') {
1267        ++LastEmitted;
1268        const char *StrStart = LastEmitted;
1269        const char *StrEnd = strchr(StrStart, '}');
1270        if (StrEnd == 0) {
1271          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1272                            + std::string(AsmStr) + "'");
1273        }
1274
1275        std::string Val(StrStart, StrEnd);
1276        PrintSpecial(MI, Val.c_str());
1277        LastEmitted = StrEnd+1;
1278        break;
1279      }
1280
1281      const char *IDStart = LastEmitted;
1282      char *IDEnd;
1283      errno = 0;
1284      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1285      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1286        llvm_report_error("Bad $ operand number in inline asm string: '"
1287                          + std::string(AsmStr) + "'");
1288      }
1289      LastEmitted = IDEnd;
1290
1291      char Modifier[2] = { 0, 0 };
1292
1293      if (HasCurlyBraces) {
1294        // If we have curly braces, check for a modifier character.  This
1295        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1296        if (*LastEmitted == ':') {
1297          ++LastEmitted;    // Consume ':' character.
1298          if (*LastEmitted == 0) {
1299            llvm_report_error("Bad ${:} expression in inline asm string: '"
1300                              + std::string(AsmStr) + "'");
1301          }
1302
1303          Modifier[0] = *LastEmitted;
1304          ++LastEmitted;    // Consume modifier character.
1305        }
1306
1307        if (*LastEmitted != '}') {
1308          llvm_report_error("Bad ${} expression in inline asm string: '"
1309                            + std::string(AsmStr) + "'");
1310        }
1311        ++LastEmitted;    // Consume '}' character.
1312      }
1313
1314      if ((unsigned)Val >= NumOperands-1) {
1315        llvm_report_error("Invalid $ operand number in inline asm string: '"
1316                          + std::string(AsmStr) + "'");
1317      }
1318
1319      // Okay, we finally have a value number.  Ask the target to print this
1320      // operand!
1321      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1322        unsigned OpNo = 1;
1323
1324        bool Error = false;
1325
1326        // Scan to find the machine operand number for the operand.
1327        for (; Val; --Val) {
1328          if (OpNo >= MI->getNumOperands()) break;
1329          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1330          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1331        }
1332
1333        if (OpNo >= MI->getNumOperands()) {
1334          Error = true;
1335        } else {
1336          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1337          ++OpNo;  // Skip over the ID number.
1338
1339          if (Modifier[0] == 'l')  // labels are target independent
1340            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1341          else {
1342            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1343            if ((OpFlags & 7) == 4) {
1344              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1345                                                Modifier[0] ? Modifier : 0);
1346            } else {
1347              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1348                                          Modifier[0] ? Modifier : 0);
1349            }
1350          }
1351        }
1352        if (Error) {
1353          std::string msg;
1354          raw_string_ostream Msg(msg);
1355          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1356          MI->print(Msg);
1357          llvm_report_error(Msg.str());
1358        }
1359      }
1360      break;
1361    }
1362    }
1363  }
1364  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1365}
1366
1367/// printImplicitDef - This method prints the specified machine instruction
1368/// that is an implicit def.
1369void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1370  if (!VerboseAsm) return;
1371  O.PadToColumn(MAI->getCommentColumn());
1372  O << MAI->getCommentString() << " implicit-def: "
1373    << TRI->getName(MI->getOperand(0).getReg());
1374}
1375
1376void AsmPrinter::printKill(const MachineInstr *MI) const {
1377  if (!VerboseAsm) return;
1378  O.PadToColumn(MAI->getCommentColumn());
1379  O << MAI->getCommentString() << " kill:";
1380  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1381    const MachineOperand &op = MI->getOperand(n);
1382    assert(op.isReg() && "KILL instruction must have only register operands");
1383    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1384  }
1385}
1386
1387/// printLabel - This method prints a local label used by debug and
1388/// exception handling tables.
1389void AsmPrinter::printLabel(const MachineInstr *MI) const {
1390  printLabel(MI->getOperand(0).getImm());
1391}
1392
1393void AsmPrinter::printLabel(unsigned Id) const {
1394  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1395}
1396
1397/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1398/// instruction, using the specified assembler variant.  Targets should
1399/// override this to format as appropriate.
1400bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1401                                 unsigned AsmVariant, const char *ExtraCode) {
1402  // Target doesn't support this yet!
1403  return true;
1404}
1405
1406bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1407                                       unsigned AsmVariant,
1408                                       const char *ExtraCode) {
1409  // Target doesn't support this yet!
1410  return true;
1411}
1412
1413MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1414                                            const char *Suffix) const {
1415  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1416}
1417
1418MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1419                                            const BasicBlock *BB,
1420                                            const char *Suffix) const {
1421  assert(BB->hasName() &&
1422         "Address of anonymous basic block not supported yet!");
1423
1424  // This code must use the function name itself, and not the function number,
1425  // since it must be possible to generate the label name from within other
1426  // functions.
1427  SmallString<60> FnName;
1428  Mang->getNameWithPrefix(FnName, F, false);
1429
1430  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1431  SmallString<60> NameResult;
1432  Mang->getNameWithPrefix(NameResult,
1433                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1434                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1435                          Mangler::Private);
1436
1437  return OutContext.GetOrCreateSymbol(NameResult.str());
1438}
1439
1440/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1441MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1442  SmallString<60> Name;
1443  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1444    << getFunctionNumber() << '_' << CPID;
1445  return OutContext.GetOrCreateSymbol(Name.str());
1446}
1447
1448/// GetJTISymbol - Return the symbol for the specified jump table entry.
1449MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1450  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1451}
1452
1453/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1454/// FIXME: privatize to AsmPrinter.
1455MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1456  SmallString<60> Name;
1457  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1458    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1459  return OutContext.GetOrCreateSymbol(Name.str());
1460}
1461
1462/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1463/// value.
1464MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1465  SmallString<60> NameStr;
1466  Mang->getNameWithPrefix(NameStr, GV, false);
1467  return OutContext.GetOrCreateSymbol(NameStr.str());
1468}
1469
1470/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1471/// global value name as its base, with the specified suffix, and where the
1472/// symbol is forced to have private linkage if ForcePrivate is true.
1473MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1474                                                   StringRef Suffix,
1475                                                   bool ForcePrivate) const {
1476  SmallString<60> NameStr;
1477  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1478  NameStr.append(Suffix.begin(), Suffix.end());
1479  return OutContext.GetOrCreateSymbol(NameStr.str());
1480}
1481
1482/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1483/// ExternalSymbol.
1484MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1485  SmallString<60> NameStr;
1486  Mang->getNameWithPrefix(NameStr, Sym);
1487  return OutContext.GetOrCreateSymbol(NameStr.str());
1488}
1489
1490
1491
1492/// PrintParentLoopComment - Print comments about parent loops of this one.
1493static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1494                                   unsigned FunctionNumber) {
1495  if (Loop == 0) return;
1496  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1497  OS.indent(Loop->getLoopDepth()*2)
1498    << "Parent Loop BB" << FunctionNumber << "_"
1499    << Loop->getHeader()->getNumber()
1500    << " Depth=" << Loop->getLoopDepth() << '\n';
1501}
1502
1503
1504/// PrintChildLoopComment - Print comments about child loops within
1505/// the loop for this basic block, with nesting.
1506static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1507                                  unsigned FunctionNumber) {
1508  // Add child loop information
1509  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1510    OS.indent((*CL)->getLoopDepth()*2)
1511      << "Child Loop BB" << FunctionNumber << "_"
1512      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1513      << '\n';
1514    PrintChildLoopComment(OS, *CL, FunctionNumber);
1515  }
1516}
1517
1518/// EmitComments - Pretty-print comments for basic blocks.
1519static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1520                                        const MachineLoopInfo *LI,
1521                                        const AsmPrinter &AP) {
1522  // Add loop depth information
1523  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1524  if (Loop == 0) return;
1525
1526  MachineBasicBlock *Header = Loop->getHeader();
1527  assert(Header && "No header for loop");
1528
1529  // If this block is not a loop header, just print out what is the loop header
1530  // and return.
1531  if (Header != &MBB) {
1532    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1533                              Twine(AP.getFunctionNumber())+"_" +
1534                              Twine(Loop->getHeader()->getNumber())+
1535                              " Depth="+Twine(Loop->getLoopDepth()));
1536    return;
1537  }
1538
1539  // Otherwise, it is a loop header.  Print out information about child and
1540  // parent loops.
1541  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1542
1543  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1544
1545  OS << "=>";
1546  OS.indent(Loop->getLoopDepth()*2-2);
1547
1548  OS << "This ";
1549  if (Loop->empty())
1550    OS << "Inner ";
1551  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1552
1553  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1554}
1555
1556
1557/// EmitBasicBlockStart - This method prints the label for the specified
1558/// MachineBasicBlock, an alignment (if present) and a comment describing
1559/// it if appropriate.
1560void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1561  // Emit an alignment directive for this block, if needed.
1562  if (unsigned Align = MBB->getAlignment())
1563    EmitAlignment(Log2_32(Align));
1564
1565  // If the block has its address taken, emit a special label to satisfy
1566  // references to the block. This is done so that we don't need to
1567  // remember the number of this label, and so that we can make
1568  // forward references to labels without knowing what their numbers
1569  // will be.
1570  if (MBB->hasAddressTaken()) {
1571    const BasicBlock *BB = MBB->getBasicBlock();
1572    if (VerboseAsm)
1573      OutStreamer.AddComment("Address Taken");
1574    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1575  }
1576
1577  // Print the main label for the block.
1578  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1579    if (VerboseAsm) {
1580      // NOTE: Want this comment at start of line.
1581      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1582      if (const BasicBlock *BB = MBB->getBasicBlock())
1583        if (BB->hasName())
1584          OutStreamer.AddComment("%" + BB->getName());
1585
1586      PrintBasicBlockLoopComments(*MBB, LI, *this);
1587      OutStreamer.AddBlankLine();
1588    }
1589  } else {
1590    if (VerboseAsm) {
1591      if (const BasicBlock *BB = MBB->getBasicBlock())
1592        if (BB->hasName())
1593          OutStreamer.AddComment("%" + BB->getName());
1594      PrintBasicBlockLoopComments(*MBB, LI, *this);
1595    }
1596
1597    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1598  }
1599}
1600
1601void AsmPrinter::printVisibility(MCSymbol *Sym, unsigned Visibility) const {
1602  // FIXME: RENAME TO EmitVisibility.
1603  MCSymbolAttr Attr = MCSA_Invalid;
1604
1605  switch (Visibility) {
1606  default: break;
1607  case GlobalValue::HiddenVisibility:
1608    Attr = MAI->getHiddenVisibilityAttr();
1609    break;
1610  case GlobalValue::ProtectedVisibility:
1611    Attr = MAI->getProtectedVisibilityAttr();
1612    break;
1613  }
1614
1615  if (Attr != MCSA_Invalid)
1616    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1617}
1618
1619void AsmPrinter::printOffset(int64_t Offset) const {
1620  if (Offset > 0)
1621    O << '+' << Offset;
1622  else if (Offset < 0)
1623    O << Offset;
1624}
1625
1626GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1627  if (!S->usesMetadata())
1628    return 0;
1629
1630  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1631  if (GCPI != GCMetadataPrinters.end())
1632    return GCPI->second;
1633
1634  const char *Name = S->getName().c_str();
1635
1636  for (GCMetadataPrinterRegistry::iterator
1637         I = GCMetadataPrinterRegistry::begin(),
1638         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1639    if (strcmp(Name, I->getName()) == 0) {
1640      GCMetadataPrinter *GMP = I->instantiate();
1641      GMP->S = S;
1642      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1643      return GMP;
1644    }
1645
1646  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1647  return 0;
1648}
1649
1650/// EmitComments - Pretty-print comments for instructions
1651void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1652  if (!VerboseAsm)
1653    return;
1654
1655  bool Newline = false;
1656
1657  if (!MI.getDebugLoc().isUnknown()) {
1658    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1659
1660    // Print source line info.
1661    O.PadToColumn(MAI->getCommentColumn());
1662    O << MAI->getCommentString() << ' ';
1663    DIScope Scope = DLT.getScope();
1664    // Omit the directory, because it's likely to be long and uninteresting.
1665    if (!Scope.isNull())
1666      O << Scope.getFilename();
1667    else
1668      O << "<unknown>";
1669    O << ':' << DLT.getLineNumber();
1670    if (DLT.getColumnNumber() != 0)
1671      O << ':' << DLT.getColumnNumber();
1672    Newline = true;
1673  }
1674
1675  // Check for spills and reloads
1676  int FI;
1677
1678  const MachineFrameInfo *FrameInfo =
1679    MI.getParent()->getParent()->getFrameInfo();
1680
1681  // We assume a single instruction only has a spill or reload, not
1682  // both.
1683  const MachineMemOperand *MMO;
1684  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1685    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1686      MMO = *MI.memoperands_begin();
1687      if (Newline) O << '\n';
1688      O.PadToColumn(MAI->getCommentColumn());
1689      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload";
1690      Newline = true;
1691    }
1692  }
1693  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1694    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1695      if (Newline) O << '\n';
1696      O.PadToColumn(MAI->getCommentColumn());
1697      O << MAI->getCommentString() << ' '
1698        << MMO->getSize() << "-byte Folded Reload";
1699      Newline = true;
1700    }
1701  }
1702  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1703    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1704      MMO = *MI.memoperands_begin();
1705      if (Newline) O << '\n';
1706      O.PadToColumn(MAI->getCommentColumn());
1707      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill";
1708      Newline = true;
1709    }
1710  }
1711  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1712    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1713      if (Newline) O << '\n';
1714      O.PadToColumn(MAI->getCommentColumn());
1715      O << MAI->getCommentString() << ' '
1716        << MMO->getSize() << "-byte Folded Spill";
1717      Newline = true;
1718    }
1719  }
1720
1721  // Check for spill-induced copies
1722  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1723  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1724                                      SrcSubIdx, DstSubIdx)) {
1725    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1726      if (Newline) O << '\n';
1727      O.PadToColumn(MAI->getCommentColumn());
1728      O << MAI->getCommentString() << " Reload Reuse";
1729    }
1730  }
1731}
1732
1733