AsmPrinter.cpp revision 071c62fad0b25ad4131e7f984173a796c1e63f61 
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), FunctionNumber(0), 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
90TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
91  return TM.getTargetLowering()->getObjFileLowering();
92}
93
94/// getCurrentSection() - Return the current section we are emitting to.
95const MCSection *AsmPrinter::getCurrentSection() const {
96  return OutStreamer.getCurrentSection();
97}
98
99
100void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
101  AU.setPreservesAll();
102  MachineFunctionPass::getAnalysisUsage(AU);
103  AU.addRequired<GCModuleInfo>();
104  if (VerboseAsm)
105    AU.addRequired<MachineLoopInfo>();
106}
107
108bool AsmPrinter::doInitialization(Module &M) {
109  // Initialize TargetLoweringObjectFile.
110  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
111    .Initialize(OutContext, TM);
112
113  Mang = new Mangler(*MAI);
114
115  // Allow the target to emit any magic that it wants at the start of the file.
116  EmitStartOfAsmFile(M);
117
118  // Very minimal debug info. It is ignored if we emit actual debug info. If we
119  // don't, this at least helps the user find where a global came from.
120  if (MAI->hasSingleParameterDotFile()) {
121    // .file "foo.c"
122    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
123  }
124
125  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
126  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
127  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
128    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
129      MP->beginAssembly(O, *this, *MAI);
130
131  if (!M.getModuleInlineAsm().empty())
132    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
133      << M.getModuleInlineAsm()
134      << '\n' << MAI->getCommentString()
135      << " End of file scope inline assembly\n";
136
137  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
138  if (MMI)
139    MMI->AnalyzeModule(M);
140  DW = getAnalysisIfAvailable<DwarfWriter>();
141  if (DW)
142    DW->BeginModule(&M, MMI, O, this, MAI);
143
144  return false;
145}
146
147/// EmitGlobalVariable - Emit the specified global variable to the .s file.
148void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
149  if (!GV->hasInitializer())   // External globals require no code.
150    return;
151
152  // Check to see if this is a special global used by LLVM, if so, emit it.
153  if (EmitSpecialLLVMGlobal(GV))
154    return;
155
156  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
157  printVisibility(GVSym, GV->getVisibility());
158
159  if (MAI->hasDotTypeDotSizeDirective())
160    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
161
162  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
163
164  const TargetData *TD = TM.getTargetData();
165  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
166  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
167
168  // Handle common and BSS local symbols (.lcomm).
169  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
170    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
171
172    if (VerboseAsm) {
173      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
174                     /*PrintType=*/false, GV->getParent());
175      OutStreamer.GetCommentOS() << '\n';
176    }
177
178    // Handle common symbols.
179    if (GVKind.isCommon()) {
180      // .comm _foo, 42, 4
181      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
182      return;
183    }
184
185    // Handle local BSS symbols.
186    if (MAI->hasMachoZeroFillDirective()) {
187      const MCSection *TheSection =
188        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
189      // .zerofill __DATA, __bss, _foo, 400, 5
190      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
191      return;
192    }
193
194    if (MAI->hasLCOMMDirective()) {
195      // .lcomm _foo, 42
196      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
197      return;
198    }
199
200    // .local _foo
201    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
202    // .comm _foo, 42, 4
203    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
204    return;
205  }
206
207  const MCSection *TheSection =
208    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
209
210  // Handle the zerofill directive on darwin, which is a special form of BSS
211  // emission.
212  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
213    // .globl _foo
214    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
215    // .zerofill __DATA, __common, _foo, 400, 5
216    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
217    return;
218  }
219
220  OutStreamer.SwitchSection(TheSection);
221
222  // TODO: Factor into an 'emit linkage' thing that is shared with function
223  // bodies.
224  switch (GV->getLinkage()) {
225  case GlobalValue::CommonLinkage:
226  case GlobalValue::LinkOnceAnyLinkage:
227  case GlobalValue::LinkOnceODRLinkage:
228  case GlobalValue::WeakAnyLinkage:
229  case GlobalValue::WeakODRLinkage:
230  case GlobalValue::LinkerPrivateLinkage:
231    if (MAI->getWeakDefDirective() != 0) {
232      // .globl _foo
233      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
234      // .weak_definition _foo
235      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
236    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
237      // .globl _foo
238      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
239      // FIXME: linkonce should be a section attribute, handled by COFF Section
240      // assignment.
241      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
242      // .linkonce same_size
243      O << LinkOnce;
244    } else {
245      // .weak _foo
246      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
247    }
248    break;
249  case GlobalValue::DLLExportLinkage:
250  case GlobalValue::AppendingLinkage:
251    // FIXME: appending linkage variables should go into a section of
252    // their name or something.  For now, just emit them as external.
253  case GlobalValue::ExternalLinkage:
254    // If external or appending, declare as a global symbol.
255    // .globl _foo
256    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
257    break;
258  case GlobalValue::PrivateLinkage:
259  case GlobalValue::InternalLinkage:
260     break;
261  default:
262    llvm_unreachable("Unknown linkage type!");
263  }
264
265  EmitAlignment(AlignLog, GV);
266  if (VerboseAsm) {
267    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
268                   /*PrintType=*/false, GV->getParent());
269    OutStreamer.GetCommentOS() << '\n';
270  }
271  OutStreamer.EmitLabel(GVSym);
272
273  EmitGlobalConstant(GV->getInitializer());
274
275  if (MAI->hasDotTypeDotSizeDirective())
276    // .size foo, 42
277    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
278
279  OutStreamer.AddBlankLine();
280}
281
282
283bool AsmPrinter::doFinalization(Module &M) {
284  // Emit global variables.
285  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
286       I != E; ++I)
287    EmitGlobalVariable(I);
288
289  // Emit final debug information.
290  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
291    DW->EndModule();
292
293  // If the target wants to know about weak references, print them all.
294  if (MAI->getWeakRefDirective()) {
295    // FIXME: This is not lazy, it would be nice to only print weak references
296    // to stuff that is actually used.  Note that doing so would require targets
297    // to notice uses in operands (due to constant exprs etc).  This should
298    // happen with the MC stuff eventually.
299
300    // Print out module-level global variables here.
301    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
302         I != E; ++I) {
303      if (!I->hasExternalWeakLinkage()) continue;
304      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
305                                      MCSA_WeakReference);
306    }
307
308    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
309      if (!I->hasExternalWeakLinkage()) continue;
310      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
311                                      MCSA_WeakReference);
312    }
313  }
314
315  if (MAI->getSetDirective()) {
316    OutStreamer.AddBlankLine();
317    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
318         I != E; ++I) {
319      MCSymbol *Name = GetGlobalValueSymbol(I);
320
321      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
322      MCSymbol *Target = GetGlobalValueSymbol(GV);
323
324      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
325        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
326      else if (I->hasWeakLinkage())
327        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
328      else
329        assert(I->hasLocalLinkage() && "Invalid alias linkage");
330
331      printVisibility(Name, I->getVisibility());
332
333      O << MAI->getSetDirective() << ' ' << *Name << ", " << *Target << '\n';
334    }
335  }
336
337  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
338  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
339  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
340    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
341      MP->finishAssembly(O, *this, *MAI);
342
343  // If we don't have any trampolines, then we don't require stack memory
344  // to be executable. Some targets have a directive to declare this.
345  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
346  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
347    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
348      OutStreamer.SwitchSection(S);
349
350  // Allow the target to emit any magic that it wants at the end of the file,
351  // after everything else has gone out.
352  EmitEndOfAsmFile(M);
353
354  delete Mang; Mang = 0;
355  DW = 0; MMI = 0;
356
357  OutStreamer.Finish();
358  return false;
359}
360
361void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
362  // Get the function symbol.
363  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
364  IncrementFunctionNumber();
365
366  if (VerboseAsm)
367    LI = &getAnalysis<MachineLoopInfo>();
368}
369
370namespace {
371  // SectionCPs - Keep track the alignment, constpool entries per Section.
372  struct SectionCPs {
373    const MCSection *S;
374    unsigned Alignment;
375    SmallVector<unsigned, 4> CPEs;
376    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
377  };
378}
379
380/// EmitConstantPool - Print to the current output stream assembly
381/// representations of the constants in the constant pool MCP. This is
382/// used to print out constants which have been "spilled to memory" by
383/// the code generator.
384///
385void AsmPrinter::EmitConstantPool(MachineConstantPool *MCP) {
386  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
387  if (CP.empty()) return;
388
389  // Calculate sections for constant pool entries. We collect entries to go into
390  // the same section together to reduce amount of section switch statements.
391  SmallVector<SectionCPs, 4> CPSections;
392  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
393    const MachineConstantPoolEntry &CPE = CP[i];
394    unsigned Align = CPE.getAlignment();
395
396    SectionKind Kind;
397    switch (CPE.getRelocationInfo()) {
398    default: llvm_unreachable("Unknown section kind");
399    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
400    case 1:
401      Kind = SectionKind::getReadOnlyWithRelLocal();
402      break;
403    case 0:
404    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
405    case 4:  Kind = SectionKind::getMergeableConst4(); break;
406    case 8:  Kind = SectionKind::getMergeableConst8(); break;
407    case 16: Kind = SectionKind::getMergeableConst16();break;
408    default: Kind = SectionKind::getMergeableConst(); break;
409    }
410    }
411
412    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
413
414    // The number of sections are small, just do a linear search from the
415    // last section to the first.
416    bool Found = false;
417    unsigned SecIdx = CPSections.size();
418    while (SecIdx != 0) {
419      if (CPSections[--SecIdx].S == S) {
420        Found = true;
421        break;
422      }
423    }
424    if (!Found) {
425      SecIdx = CPSections.size();
426      CPSections.push_back(SectionCPs(S, Align));
427    }
428
429    if (Align > CPSections[SecIdx].Alignment)
430      CPSections[SecIdx].Alignment = Align;
431    CPSections[SecIdx].CPEs.push_back(i);
432  }
433
434  // Now print stuff into the calculated sections.
435  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
436    OutStreamer.SwitchSection(CPSections[i].S);
437    EmitAlignment(Log2_32(CPSections[i].Alignment));
438
439    unsigned Offset = 0;
440    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
441      unsigned CPI = CPSections[i].CPEs[j];
442      MachineConstantPoolEntry CPE = CP[CPI];
443
444      // Emit inter-object padding for alignment.
445      unsigned AlignMask = CPE.getAlignment() - 1;
446      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
447      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
448
449      const Type *Ty = CPE.getType();
450      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
451
452      // Emit the label with a comment on it.
453      if (VerboseAsm) {
454        OutStreamer.GetCommentOS() << "constant pool ";
455        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
456                          MF->getFunction()->getParent());
457        OutStreamer.GetCommentOS() << '\n';
458      }
459      OutStreamer.EmitLabel(GetCPISymbol(CPI));
460
461      if (CPE.isMachineConstantPoolEntry())
462        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
463      else
464        EmitGlobalConstant(CPE.Val.ConstVal);
465    }
466  }
467}
468
469/// EmitJumpTableInfo - Print assembly representations of the jump tables used
470/// by the current function to the current output stream.
471///
472void AsmPrinter::EmitJumpTableInfo(MachineFunction &MF) {
473  MachineJumpTableInfo *MJTI = MF.getJumpTableInfo();
474  if (MJTI == 0) return;
475  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
476  if (JT.empty()) return;
477
478  bool IsPic = TM.getRelocationModel() == Reloc::PIC_;
479
480  // Pick the directive to use to print the jump table entries, and switch to
481  // the appropriate section.
482  TargetLowering *LoweringInfo = TM.getTargetLowering();
483
484  const Function *F = MF.getFunction();
485  bool JTInDiffSection = false;
486  if (F->isWeakForLinker() ||
487      (IsPic && !LoweringInfo->usesGlobalOffsetTable())) {
488    // In PIC mode, we need to emit the jump table to the same section as the
489    // function body itself, otherwise the label differences won't make sense.
490    // We should also do if the section name is NULL or function is declared in
491    // discardable section.
492    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang,
493                                                                    TM));
494  } else {
495    // Otherwise, drop it in the readonly section.
496    const MCSection *ReadOnlySection =
497      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
498    OutStreamer.SwitchSection(ReadOnlySection);
499    JTInDiffSection = true;
500  }
501
502  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
503  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
504
505  for (unsigned i = 0, e = JT.size(); i != e; ++i) {
506    const std::vector<MachineBasicBlock*> &JTBBs = JT[i].MBBs;
507
508    // If this jump table was deleted, ignore it.
509    if (JTBBs.empty()) continue;
510
511    // For PIC codegen, if possible we want to use the SetDirective to reduce
512    // the number of relocations the assembler will generate for the jump table.
513    // Set directives are all printed before the jump table itself.
514    SmallPtrSet<MachineBasicBlock*, 16> EmittedSets;
515    if (MAI->getSetDirective() && IsPic)
516      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
517        if (EmittedSets.insert(JTBBs[ii]))
518          printPICJumpTableSetLabel(i, JTBBs[ii]);
519
520    // On some targets (e.g. Darwin) we want to emit two consequtive labels
521    // before each jump table.  The first label is never referenced, but tells
522    // the assembler and linker the extents of the jump table object.  The
523    // second label is actually referenced by the code.
524    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
525      OutStreamer.EmitLabel(GetJTISymbol(i, true));
526
527    OutStreamer.EmitLabel(GetJTISymbol(i));
528
529    if (!IsPic) {
530      // In non-pic mode, the entries in the jump table are direct references
531      // to the basic blocks.
532      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
533        MCSymbol *MBBSym = GetMBBSymbol(JTBBs[ii]->getNumber());
534        OutStreamer.EmitValue(MCSymbolRefExpr::Create(MBBSym, OutContext),
535                              EntrySize, /*addrspace*/0);
536      }
537    } else {
538      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
539        printPICJumpTableEntry(MJTI, JTBBs[ii], i);
540    }
541  }
542}
543
544void AsmPrinter::printPICJumpTableEntry(const MachineJumpTableInfo *MJTI,
545                                        const MachineBasicBlock *MBB,
546                                        unsigned uid)  const {
547  // If the target supports GPRel, use it.
548  if (MAI->getGPRel32Directive() != 0) {
549    MCSymbol *MBBSym = GetMBBSymbol(MBB->getNumber());
550    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
551    return;
552  }
553
554  // If we have emitted set directives for the jump table entries, print
555  // them rather than the entries themselves.  If we're emitting PIC, then
556  // emit the table entries as differences between two text section labels.
557  const MCExpr *Val;
558  if (MAI->getSetDirective()) {
559    // If we used .set, reference the .set's symbol.
560    Val = MCSymbolRefExpr::Create(GetJTSetSymbol(uid, MBB->getNumber()),
561                                  OutContext);
562  } else {
563    // Otherwise, use the difference as the jump table entry.
564    Val = MCSymbolRefExpr::Create(GetMBBSymbol(MBB->getNumber()), OutContext);
565    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(uid), OutContext);
566    Val = MCBinaryExpr::CreateSub(Val, JTI, OutContext);
567  }
568
569  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
570  OutStreamer.EmitValue(Val, EntrySize, /*addrspace*/0);
571}
572
573
574/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
575/// special global used by LLVM.  If so, emit it and return true, otherwise
576/// do nothing and return false.
577bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
578  if (GV->getName() == "llvm.used") {
579    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
580      EmitLLVMUsedList(GV->getInitializer());
581    return true;
582  }
583
584  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
585  if (GV->getSection() == "llvm.metadata" ||
586      GV->hasAvailableExternallyLinkage())
587    return true;
588
589  if (!GV->hasAppendingLinkage()) return false;
590
591  assert(GV->hasInitializer() && "Not a special LLVM global!");
592
593  const TargetData *TD = TM.getTargetData();
594  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
595  if (GV->getName() == "llvm.global_ctors") {
596    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
597    EmitAlignment(Align, 0);
598    EmitXXStructorList(GV->getInitializer());
599
600    if (TM.getRelocationModel() == Reloc::Static &&
601        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
602      StringRef Sym(".constructors_used");
603      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
604                                      MCSA_Reference);
605    }
606    return true;
607  }
608
609  if (GV->getName() == "llvm.global_dtors") {
610    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
611    EmitAlignment(Align, 0);
612    EmitXXStructorList(GV->getInitializer());
613
614    if (TM.getRelocationModel() == Reloc::Static &&
615        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
616      StringRef Sym(".destructors_used");
617      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
618                                      MCSA_Reference);
619    }
620    return true;
621  }
622
623  return false;
624}
625
626/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
627/// global in the specified llvm.used list for which emitUsedDirectiveFor
628/// is true, as being used with this directive.
629void AsmPrinter::EmitLLVMUsedList(Constant *List) {
630  // Should be an array of 'i8*'.
631  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
632  if (InitList == 0) return;
633
634  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
635    const GlobalValue *GV =
636      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
637    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
638      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
639                                      MCSA_NoDeadStrip);
640  }
641}
642
643/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
644/// function pointers, ignoring the init priority.
645void AsmPrinter::EmitXXStructorList(Constant *List) {
646  // Should be an array of '{ int, void ()* }' structs.  The first value is the
647  // init priority, which we ignore.
648  if (!isa<ConstantArray>(List)) return;
649  ConstantArray *InitList = cast<ConstantArray>(List);
650  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
651    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
652      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
653
654      if (CS->getOperand(1)->isNullValue())
655        return;  // Found a null terminator, exit printing.
656      // Emit the function pointer.
657      EmitGlobalConstant(CS->getOperand(1));
658    }
659}
660
661//===--------------------------------------------------------------------===//
662// Emission and print routines
663//
664
665/// EmitInt8 - Emit a byte directive and value.
666///
667void AsmPrinter::EmitInt8(int Value) const {
668  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
669}
670
671/// EmitInt16 - Emit a short directive and value.
672///
673void AsmPrinter::EmitInt16(int Value) const {
674  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
675}
676
677/// EmitInt32 - Emit a long directive and value.
678///
679void AsmPrinter::EmitInt32(int Value) const {
680  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
681}
682
683/// EmitInt64 - Emit a long long directive and value.
684///
685void AsmPrinter::EmitInt64(uint64_t Value) const {
686  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
687}
688
689//===----------------------------------------------------------------------===//
690
691// EmitAlignment - Emit an alignment directive to the specified power of
692// two boundary.  For example, if you pass in 3 here, you will get an 8
693// byte alignment.  If a global value is specified, and if that global has
694// an explicit alignment requested, it will unconditionally override the
695// alignment request.  However, if ForcedAlignBits is specified, this value
696// has final say: the ultimate alignment will be the max of ForcedAlignBits
697// and the alignment computed with NumBits and the global.
698//
699// The algorithm is:
700//     Align = NumBits;
701//     if (GV && GV->hasalignment) Align = GV->getalignment();
702//     Align = std::max(Align, ForcedAlignBits);
703//
704void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
705                               unsigned ForcedAlignBits,
706                               bool UseFillExpr) const {
707  if (GV && GV->getAlignment())
708    NumBits = Log2_32(GV->getAlignment());
709  NumBits = std::max(NumBits, ForcedAlignBits);
710
711  if (NumBits == 0) return;   // No need to emit alignment.
712
713  unsigned FillValue = 0;
714  if (getCurrentSection()->getKind().isText())
715    FillValue = MAI->getTextAlignFillValue();
716
717  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
718}
719
720/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
721///
722static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
723  MCContext &Ctx = AP.OutContext;
724
725  if (CV->isNullValue() || isa<UndefValue>(CV))
726    return MCConstantExpr::Create(0, Ctx);
727
728  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
729    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
730
731  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
732    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
733  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
734    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
735
736  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
737  if (CE == 0) {
738    llvm_unreachable("Unknown constant value to lower!");
739    return MCConstantExpr::Create(0, Ctx);
740  }
741
742  switch (CE->getOpcode()) {
743  case Instruction::ZExt:
744  case Instruction::SExt:
745  case Instruction::FPTrunc:
746  case Instruction::FPExt:
747  case Instruction::UIToFP:
748  case Instruction::SIToFP:
749  case Instruction::FPToUI:
750  case Instruction::FPToSI:
751  default: llvm_unreachable("FIXME: Don't support this constant cast expr");
752  case Instruction::GetElementPtr: {
753    const TargetData &TD = *AP.TM.getTargetData();
754    // Generate a symbolic expression for the byte address
755    const Constant *PtrVal = CE->getOperand(0);
756    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
757    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
758                                         IdxVec.size());
759
760    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
761    if (Offset == 0)
762      return Base;
763
764    // Truncate/sext the offset to the pointer size.
765    if (TD.getPointerSizeInBits() != 64) {
766      int SExtAmount = 64-TD.getPointerSizeInBits();
767      Offset = (Offset << SExtAmount) >> SExtAmount;
768    }
769
770    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
771                                   Ctx);
772  }
773
774  case Instruction::Trunc:
775    // We emit the value and depend on the assembler to truncate the generated
776    // expression properly.  This is important for differences between
777    // blockaddress labels.  Since the two labels are in the same function, it
778    // is reasonable to treat their delta as a 32-bit value.
779    // FALL THROUGH.
780  case Instruction::BitCast:
781    return LowerConstant(CE->getOperand(0), AP);
782
783  case Instruction::IntToPtr: {
784    const TargetData &TD = *AP.TM.getTargetData();
785    // Handle casts to pointers by changing them into casts to the appropriate
786    // integer type.  This promotes constant folding and simplifies this code.
787    Constant *Op = CE->getOperand(0);
788    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
789                                      false/*ZExt*/);
790    return LowerConstant(Op, AP);
791  }
792
793  case Instruction::PtrToInt: {
794    const TargetData &TD = *AP.TM.getTargetData();
795    // Support only foldable casts to/from pointers that can be eliminated by
796    // changing the pointer to the appropriately sized integer type.
797    Constant *Op = CE->getOperand(0);
798    const Type *Ty = CE->getType();
799
800    const MCExpr *OpExpr = LowerConstant(Op, AP);
801
802    // We can emit the pointer value into this slot if the slot is an
803    // integer slot equal to the size of the pointer.
804    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
805      return OpExpr;
806
807    // Otherwise the pointer is smaller than the resultant integer, mask off
808    // the high bits so we are sure to get a proper truncation if the input is
809    // a constant expr.
810    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
811    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
812    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
813  }
814
815  case Instruction::Add:
816  case Instruction::Sub:
817  case Instruction::And:
818  case Instruction::Or:
819  case Instruction::Xor: {
820    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
821    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
822    switch (CE->getOpcode()) {
823    default: llvm_unreachable("Unknown binary operator constant cast expr");
824    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
825    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
826    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
827    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
828    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
829    }
830  }
831  }
832}
833
834static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
835                                    AsmPrinter &AP) {
836  if (AddrSpace != 0 || !CA->isString()) {
837    // Not a string.  Print the values in successive locations
838    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
839      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
840    return;
841  }
842
843  // Otherwise, it can be emitted as .ascii.
844  SmallVector<char, 128> TmpVec;
845  TmpVec.reserve(CA->getNumOperands());
846  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
847    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
848
849  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
850}
851
852static void EmitGlobalConstantVector(const ConstantVector *CV,
853                                     unsigned AddrSpace, AsmPrinter &AP) {
854  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
855    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
856}
857
858static void EmitGlobalConstantStruct(const ConstantStruct *CS,
859                                     unsigned AddrSpace, AsmPrinter &AP) {
860  // Print the fields in successive locations. Pad to align if needed!
861  const TargetData *TD = AP.TM.getTargetData();
862  unsigned Size = TD->getTypeAllocSize(CS->getType());
863  const StructLayout *Layout = TD->getStructLayout(CS->getType());
864  uint64_t SizeSoFar = 0;
865  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
866    const Constant *Field = CS->getOperand(i);
867
868    // Check if padding is needed and insert one or more 0s.
869    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
870    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
871                        - Layout->getElementOffset(i)) - FieldSize;
872    SizeSoFar += FieldSize + PadSize;
873
874    // Now print the actual field value.
875    AP.EmitGlobalConstant(Field, AddrSpace);
876
877    // Insert padding - this may include padding to increase the size of the
878    // current field up to the ABI size (if the struct is not packed) as well
879    // as padding to ensure that the next field starts at the right offset.
880    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
881  }
882  assert(SizeSoFar == Layout->getSizeInBytes() &&
883         "Layout of constant struct may be incorrect!");
884}
885
886static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
887                                 AsmPrinter &AP) {
888  // FP Constants are printed as integer constants to avoid losing
889  // precision.
890  if (CFP->getType()->isDoubleTy()) {
891    if (AP.VerboseAsm) {
892      double Val = CFP->getValueAPF().convertToDouble();
893      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
894    }
895
896    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
897    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
898    return;
899  }
900
901  if (CFP->getType()->isFloatTy()) {
902    if (AP.VerboseAsm) {
903      float Val = CFP->getValueAPF().convertToFloat();
904      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
905    }
906    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
907    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
908    return;
909  }
910
911  if (CFP->getType()->isX86_FP80Ty()) {
912    // all long double variants are printed as hex
913    // api needed to prevent premature destruction
914    APInt API = CFP->getValueAPF().bitcastToAPInt();
915    const uint64_t *p = API.getRawData();
916    if (AP.VerboseAsm) {
917      // Convert to double so we can print the approximate val as a comment.
918      APFloat DoubleVal = CFP->getValueAPF();
919      bool ignored;
920      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
921                        &ignored);
922      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
923        << DoubleVal.convertToDouble() << '\n';
924    }
925
926    if (AP.TM.getTargetData()->isBigEndian()) {
927      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
928      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
929    } else {
930      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
931      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
932    }
933
934    // Emit the tail padding for the long double.
935    const TargetData &TD = *AP.TM.getTargetData();
936    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
937                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
938    return;
939  }
940
941  assert(CFP->getType()->isPPC_FP128Ty() &&
942         "Floating point constant type not handled");
943  // All long double variants are printed as hex api needed to prevent
944  // premature destruction.
945  APInt API = CFP->getValueAPF().bitcastToAPInt();
946  const uint64_t *p = API.getRawData();
947  if (AP.TM.getTargetData()->isBigEndian()) {
948    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
949    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
950  } else {
951    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
952    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
953  }
954}
955
956static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
957                                       unsigned AddrSpace, AsmPrinter &AP) {
958  const TargetData *TD = AP.TM.getTargetData();
959  unsigned BitWidth = CI->getBitWidth();
960  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
961
962  // We don't expect assemblers to support integer data directives
963  // for more than 64 bits, so we emit the data in at most 64-bit
964  // quantities at a time.
965  const uint64_t *RawData = CI->getValue().getRawData();
966  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
967    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
968    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
969  }
970}
971
972/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
973void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
974  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
975    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
976    return OutStreamer.EmitZeros(Size, AddrSpace);
977  }
978
979  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
980    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
981    switch (Size) {
982    case 1:
983    case 2:
984    case 4:
985    case 8:
986      if (VerboseAsm)
987        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
988      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
989      return;
990    default:
991      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
992      return;
993    }
994  }
995
996  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
997    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
998
999  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1000    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1001
1002  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1003    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1004
1005  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1006    return EmitGlobalConstantVector(V, AddrSpace, *this);
1007
1008  if (isa<ConstantPointerNull>(CV)) {
1009    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1010    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1011    return;
1012  }
1013
1014  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1015  // thread the streamer with EmitValue.
1016  OutStreamer.EmitValue(LowerConstant(CV, *this),
1017                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1018                        AddrSpace);
1019}
1020
1021void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1022  // Target doesn't support this yet!
1023  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1024}
1025
1026/// PrintSpecial - Print information related to the specified machine instr
1027/// that is independent of the operand, and may be independent of the instr
1028/// itself.  This can be useful for portably encoding the comment character
1029/// or other bits of target-specific knowledge into the asmstrings.  The
1030/// syntax used is ${:comment}.  Targets can override this to add support
1031/// for their own strange codes.
1032void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1033  if (!strcmp(Code, "private")) {
1034    O << MAI->getPrivateGlobalPrefix();
1035  } else if (!strcmp(Code, "comment")) {
1036    if (VerboseAsm)
1037      O << MAI->getCommentString();
1038  } else if (!strcmp(Code, "uid")) {
1039    // Comparing the address of MI isn't sufficient, because machineinstrs may
1040    // be allocated to the same address across functions.
1041    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1042
1043    // If this is a new LastFn instruction, bump the counter.
1044    if (LastMI != MI || LastFn != ThisF) {
1045      ++Counter;
1046      LastMI = MI;
1047      LastFn = ThisF;
1048    }
1049    O << Counter;
1050  } else {
1051    std::string msg;
1052    raw_string_ostream Msg(msg);
1053    Msg << "Unknown special formatter '" << Code
1054         << "' for machine instr: " << *MI;
1055    llvm_report_error(Msg.str());
1056  }
1057}
1058
1059/// processDebugLoc - Processes the debug information of each machine
1060/// instruction's DebugLoc.
1061void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1062                                 bool BeforePrintingInsn) {
1063  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1064      || !DW->ShouldEmitDwarfDebug())
1065    return;
1066  DebugLoc DL = MI->getDebugLoc();
1067  if (DL.isUnknown())
1068    return;
1069  DILocation CurDLT = MF->getDILocation(DL);
1070  if (CurDLT.getScope().isNull())
1071    return;
1072
1073  if (!BeforePrintingInsn) {
1074    // After printing instruction
1075    DW->EndScope(MI);
1076  } else if (CurDLT.getNode() != PrevDLT) {
1077    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1078                                      CurDLT.getColumnNumber(),
1079                                      CurDLT.getScope().getNode());
1080    printLabel(L);
1081    O << '\n';
1082    DW->BeginScope(MI, L);
1083    PrevDLT = CurDLT.getNode();
1084  }
1085}
1086
1087
1088/// printInlineAsm - This method formats and prints the specified machine
1089/// instruction that is an inline asm.
1090void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1091  unsigned NumOperands = MI->getNumOperands();
1092
1093  // Count the number of register definitions.
1094  unsigned NumDefs = 0;
1095  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1096       ++NumDefs)
1097    assert(NumDefs != NumOperands-1 && "No asm string?");
1098
1099  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1100
1101  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1102  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1103
1104  O << '\t';
1105
1106  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1107  // These are useful to see where empty asm's wound up.
1108  if (AsmStr[0] == 0) {
1109    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1110    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1111    return;
1112  }
1113
1114  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1115
1116  // The variant of the current asmprinter.
1117  int AsmPrinterVariant = MAI->getAssemblerDialect();
1118
1119  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1120  const char *LastEmitted = AsmStr; // One past the last character emitted.
1121
1122  while (*LastEmitted) {
1123    switch (*LastEmitted) {
1124    default: {
1125      // Not a special case, emit the string section literally.
1126      const char *LiteralEnd = LastEmitted+1;
1127      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1128             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1129        ++LiteralEnd;
1130      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1131        O.write(LastEmitted, LiteralEnd-LastEmitted);
1132      LastEmitted = LiteralEnd;
1133      break;
1134    }
1135    case '\n':
1136      ++LastEmitted;   // Consume newline character.
1137      O << '\n';       // Indent code with newline.
1138      break;
1139    case '$': {
1140      ++LastEmitted;   // Consume '$' character.
1141      bool Done = true;
1142
1143      // Handle escapes.
1144      switch (*LastEmitted) {
1145      default: Done = false; break;
1146      case '$':     // $$ -> $
1147        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1148          O << '$';
1149        ++LastEmitted;  // Consume second '$' character.
1150        break;
1151      case '(':             // $( -> same as GCC's { character.
1152        ++LastEmitted;      // Consume '(' character.
1153        if (CurVariant != -1) {
1154          llvm_report_error("Nested variants found in inline asm string: '"
1155                            + std::string(AsmStr) + "'");
1156        }
1157        CurVariant = 0;     // We're in the first variant now.
1158        break;
1159      case '|':
1160        ++LastEmitted;  // consume '|' character.
1161        if (CurVariant == -1)
1162          O << '|';       // this is gcc's behavior for | outside a variant
1163        else
1164          ++CurVariant;   // We're in the next variant.
1165        break;
1166      case ')':         // $) -> same as GCC's } char.
1167        ++LastEmitted;  // consume ')' character.
1168        if (CurVariant == -1)
1169          O << '}';     // this is gcc's behavior for } outside a variant
1170        else
1171          CurVariant = -1;
1172        break;
1173      }
1174      if (Done) break;
1175
1176      bool HasCurlyBraces = false;
1177      if (*LastEmitted == '{') {     // ${variable}
1178        ++LastEmitted;               // Consume '{' character.
1179        HasCurlyBraces = true;
1180      }
1181
1182      // If we have ${:foo}, then this is not a real operand reference, it is a
1183      // "magic" string reference, just like in .td files.  Arrange to call
1184      // PrintSpecial.
1185      if (HasCurlyBraces && *LastEmitted == ':') {
1186        ++LastEmitted;
1187        const char *StrStart = LastEmitted;
1188        const char *StrEnd = strchr(StrStart, '}');
1189        if (StrEnd == 0) {
1190          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1191                            + std::string(AsmStr) + "'");
1192        }
1193
1194        std::string Val(StrStart, StrEnd);
1195        PrintSpecial(MI, Val.c_str());
1196        LastEmitted = StrEnd+1;
1197        break;
1198      }
1199
1200      const char *IDStart = LastEmitted;
1201      char *IDEnd;
1202      errno = 0;
1203      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1204      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1205        llvm_report_error("Bad $ operand number in inline asm string: '"
1206                          + std::string(AsmStr) + "'");
1207      }
1208      LastEmitted = IDEnd;
1209
1210      char Modifier[2] = { 0, 0 };
1211
1212      if (HasCurlyBraces) {
1213        // If we have curly braces, check for a modifier character.  This
1214        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1215        if (*LastEmitted == ':') {
1216          ++LastEmitted;    // Consume ':' character.
1217          if (*LastEmitted == 0) {
1218            llvm_report_error("Bad ${:} expression in inline asm string: '"
1219                              + std::string(AsmStr) + "'");
1220          }
1221
1222          Modifier[0] = *LastEmitted;
1223          ++LastEmitted;    // Consume modifier character.
1224        }
1225
1226        if (*LastEmitted != '}') {
1227          llvm_report_error("Bad ${} expression in inline asm string: '"
1228                            + std::string(AsmStr) + "'");
1229        }
1230        ++LastEmitted;    // Consume '}' character.
1231      }
1232
1233      if ((unsigned)Val >= NumOperands-1) {
1234        llvm_report_error("Invalid $ operand number in inline asm string: '"
1235                          + std::string(AsmStr) + "'");
1236      }
1237
1238      // Okay, we finally have a value number.  Ask the target to print this
1239      // operand!
1240      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1241        unsigned OpNo = 1;
1242
1243        bool Error = false;
1244
1245        // Scan to find the machine operand number for the operand.
1246        for (; Val; --Val) {
1247          if (OpNo >= MI->getNumOperands()) break;
1248          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1249          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1250        }
1251
1252        if (OpNo >= MI->getNumOperands()) {
1253          Error = true;
1254        } else {
1255          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1256          ++OpNo;  // Skip over the ID number.
1257
1258          if (Modifier[0] == 'l')  // labels are target independent
1259            O << *GetMBBSymbol(MI->getOperand(OpNo).getMBB()->getNumber());
1260          else {
1261            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1262            if ((OpFlags & 7) == 4) {
1263              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1264                                                Modifier[0] ? Modifier : 0);
1265            } else {
1266              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1267                                          Modifier[0] ? Modifier : 0);
1268            }
1269          }
1270        }
1271        if (Error) {
1272          std::string msg;
1273          raw_string_ostream Msg(msg);
1274          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1275          MI->print(Msg);
1276          llvm_report_error(Msg.str());
1277        }
1278      }
1279      break;
1280    }
1281    }
1282  }
1283  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd();
1284}
1285
1286/// printImplicitDef - This method prints the specified machine instruction
1287/// that is an implicit def.
1288void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1289  if (!VerboseAsm) return;
1290  O.PadToColumn(MAI->getCommentColumn());
1291  O << MAI->getCommentString() << " implicit-def: "
1292    << TRI->getName(MI->getOperand(0).getReg());
1293}
1294
1295void AsmPrinter::printKill(const MachineInstr *MI) const {
1296  if (!VerboseAsm) return;
1297  O.PadToColumn(MAI->getCommentColumn());
1298  O << MAI->getCommentString() << " kill:";
1299  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1300    const MachineOperand &op = MI->getOperand(n);
1301    assert(op.isReg() && "KILL instruction must have only register operands");
1302    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1303  }
1304}
1305
1306/// printLabel - This method prints a local label used by debug and
1307/// exception handling tables.
1308void AsmPrinter::printLabel(const MachineInstr *MI) const {
1309  printLabel(MI->getOperand(0).getImm());
1310}
1311
1312void AsmPrinter::printLabel(unsigned Id) const {
1313  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1314}
1315
1316/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1317/// instruction, using the specified assembler variant.  Targets should
1318/// override this to format as appropriate.
1319bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1320                                 unsigned AsmVariant, const char *ExtraCode) {
1321  // Target doesn't support this yet!
1322  return true;
1323}
1324
1325bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1326                                       unsigned AsmVariant,
1327                                       const char *ExtraCode) {
1328  // Target doesn't support this yet!
1329  return true;
1330}
1331
1332MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1333                                            const char *Suffix) const {
1334  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1335}
1336
1337MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1338                                            const BasicBlock *BB,
1339                                            const char *Suffix) const {
1340  assert(BB->hasName() &&
1341         "Address of anonymous basic block not supported yet!");
1342
1343  // This code must use the function name itself, and not the function number,
1344  // since it must be possible to generate the label name from within other
1345  // functions.
1346  SmallString<60> FnName;
1347  Mang->getNameWithPrefix(FnName, F, false);
1348
1349  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1350  SmallString<60> NameResult;
1351  Mang->getNameWithPrefix(NameResult,
1352                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1353                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1354                          Mangler::Private);
1355
1356  return OutContext.GetOrCreateSymbol(NameResult.str());
1357}
1358
1359MCSymbol *AsmPrinter::GetMBBSymbol(unsigned MBBID) const {
1360  SmallString<60> Name;
1361  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "BB"
1362    << getFunctionNumber() << '_' << MBBID;
1363  return OutContext.GetOrCreateSymbol(Name.str());
1364}
1365
1366/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1367MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1368  SmallString<60> Name;
1369  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1370    << getFunctionNumber() << '_' << CPID;
1371  return OutContext.GetOrCreateSymbol(Name.str());
1372}
1373
1374/// GetJTISymbol - Return the symbol for the specified jump table entry.
1375MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1376  const char *Prefix = isLinkerPrivate ? MAI->getLinkerPrivateGlobalPrefix() :
1377                                         MAI->getPrivateGlobalPrefix();
1378  SmallString<60> Name;
1379  raw_svector_ostream(Name) << Prefix << "JTI" << getFunctionNumber() << '_'
1380    << JTID;
1381  return OutContext.GetOrCreateSymbol(Name.str());
1382}
1383
1384/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1385/// FIXME: privatize to AsmPrinter.
1386MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1387  SmallString<60> Name;
1388  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1389    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1390  return OutContext.GetOrCreateSymbol(Name.str());
1391}
1392
1393/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1394/// value.
1395MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1396  SmallString<60> NameStr;
1397  Mang->getNameWithPrefix(NameStr, GV, false);
1398  return OutContext.GetOrCreateSymbol(NameStr.str());
1399}
1400
1401/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1402/// global value name as its base, with the specified suffix, and where the
1403/// symbol is forced to have private linkage if ForcePrivate is true.
1404MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1405                                                   StringRef Suffix,
1406                                                   bool ForcePrivate) const {
1407  SmallString<60> NameStr;
1408  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1409  NameStr.append(Suffix.begin(), Suffix.end());
1410  return OutContext.GetOrCreateSymbol(NameStr.str());
1411}
1412
1413/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1414/// ExternalSymbol.
1415MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1416  SmallString<60> NameStr;
1417  Mang->getNameWithPrefix(NameStr, Sym);
1418  return OutContext.GetOrCreateSymbol(NameStr.str());
1419}
1420
1421
1422
1423/// PrintParentLoopComment - Print comments about parent loops of this one.
1424static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1425                                   unsigned FunctionNumber) {
1426  if (Loop == 0) return;
1427  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1428  OS.indent(Loop->getLoopDepth()*2)
1429    << "Parent Loop BB" << FunctionNumber << "_"
1430    << Loop->getHeader()->getNumber()
1431    << " Depth=" << Loop->getLoopDepth() << '\n';
1432}
1433
1434
1435/// PrintChildLoopComment - Print comments about child loops within
1436/// the loop for this basic block, with nesting.
1437static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1438                                  unsigned FunctionNumber) {
1439  // Add child loop information
1440  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1441    OS.indent((*CL)->getLoopDepth()*2)
1442      << "Child Loop BB" << FunctionNumber << "_"
1443      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1444      << '\n';
1445    PrintChildLoopComment(OS, *CL, FunctionNumber);
1446  }
1447}
1448
1449/// EmitComments - Pretty-print comments for basic blocks.
1450static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1451                                        const MachineLoopInfo *LI,
1452                                        const AsmPrinter &AP) {
1453  // Add loop depth information
1454  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1455  if (Loop == 0) return;
1456
1457  MachineBasicBlock *Header = Loop->getHeader();
1458  assert(Header && "No header for loop");
1459
1460  // If this block is not a loop header, just print out what is the loop header
1461  // and return.
1462  if (Header != &MBB) {
1463    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1464                              Twine(AP.getFunctionNumber())+"_" +
1465                              Twine(Loop->getHeader()->getNumber())+
1466                              " Depth="+Twine(Loop->getLoopDepth()));
1467    return;
1468  }
1469
1470  // Otherwise, it is a loop header.  Print out information about child and
1471  // parent loops.
1472  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1473
1474  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1475
1476  OS << "=>";
1477  OS.indent(Loop->getLoopDepth()*2-2);
1478
1479  OS << "This ";
1480  if (Loop->empty())
1481    OS << "Inner ";
1482  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1483
1484  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1485}
1486
1487
1488/// EmitBasicBlockStart - This method prints the label for the specified
1489/// MachineBasicBlock, an alignment (if present) and a comment describing
1490/// it if appropriate.
1491void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1492  // Emit an alignment directive for this block, if needed.
1493  if (unsigned Align = MBB->getAlignment())
1494    EmitAlignment(Log2_32(Align));
1495
1496  // If the block has its address taken, emit a special label to satisfy
1497  // references to the block. This is done so that we don't need to
1498  // remember the number of this label, and so that we can make
1499  // forward references to labels without knowing what their numbers
1500  // will be.
1501  if (MBB->hasAddressTaken()) {
1502    const BasicBlock *BB = MBB->getBasicBlock();
1503    if (VerboseAsm)
1504      OutStreamer.AddComment("Address Taken");
1505    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1506  }
1507
1508  // Print the main label for the block.
1509  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1510    if (VerboseAsm) {
1511      // NOTE: Want this comment at start of line.
1512      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1513      if (const BasicBlock *BB = MBB->getBasicBlock())
1514        if (BB->hasName())
1515          OutStreamer.AddComment("%" + BB->getName());
1516
1517      PrintBasicBlockLoopComments(*MBB, LI, *this);
1518      OutStreamer.AddBlankLine();
1519    }
1520  } else {
1521    if (VerboseAsm) {
1522      if (const BasicBlock *BB = MBB->getBasicBlock())
1523        if (BB->hasName())
1524          OutStreamer.AddComment("%" + BB->getName());
1525      PrintBasicBlockLoopComments(*MBB, LI, *this);
1526    }
1527
1528    OutStreamer.EmitLabel(GetMBBSymbol(MBB->getNumber()));
1529  }
1530}
1531
1532/// printPICJumpTableSetLabel - This method prints a set label for the
1533/// specified MachineBasicBlock for a jumptable entry.
1534void AsmPrinter::printPICJumpTableSetLabel(unsigned uid,
1535                                           const MachineBasicBlock *MBB) const {
1536  if (!MAI->getSetDirective())
1537    return;
1538
1539  O << MAI->getSetDirective() << ' ' << MAI->getPrivateGlobalPrefix()
1540    << *GetJTSetSymbol(uid, MBB->getNumber()) << ','
1541    << *GetMBBSymbol(MBB->getNumber()) << '-' << *GetJTISymbol(uid) << '\n';
1542}
1543
1544void AsmPrinter::printVisibility(MCSymbol *Sym, unsigned Visibility) const {
1545  MCSymbolAttr Attr = MCSA_Invalid;
1546
1547  switch (Visibility) {
1548  default: break;
1549  case GlobalValue::HiddenVisibility:
1550    Attr = MAI->getHiddenVisibilityAttr();
1551    break;
1552  case GlobalValue::ProtectedVisibility:
1553    Attr = MAI->getProtectedVisibilityAttr();
1554    break;
1555  }
1556
1557  if (Attr != MCSA_Invalid)
1558    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1559}
1560
1561void AsmPrinter::printOffset(int64_t Offset) const {
1562  if (Offset > 0)
1563    O << '+' << Offset;
1564  else if (Offset < 0)
1565    O << Offset;
1566}
1567
1568GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1569  if (!S->usesMetadata())
1570    return 0;
1571
1572  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1573  if (GCPI != GCMetadataPrinters.end())
1574    return GCPI->second;
1575
1576  const char *Name = S->getName().c_str();
1577
1578  for (GCMetadataPrinterRegistry::iterator
1579         I = GCMetadataPrinterRegistry::begin(),
1580         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1581    if (strcmp(Name, I->getName()) == 0) {
1582      GCMetadataPrinter *GMP = I->instantiate();
1583      GMP->S = S;
1584      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1585      return GMP;
1586    }
1587
1588  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1589  return 0;
1590}
1591
1592/// EmitComments - Pretty-print comments for instructions
1593void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1594  if (!VerboseAsm)
1595    return;
1596
1597  bool Newline = false;
1598
1599  if (!MI.getDebugLoc().isUnknown()) {
1600    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1601
1602    // Print source line info.
1603    O.PadToColumn(MAI->getCommentColumn());
1604    O << MAI->getCommentString() << ' ';
1605    DIScope Scope = DLT.getScope();
1606    // Omit the directory, because it's likely to be long and uninteresting.
1607    if (!Scope.isNull())
1608      O << Scope.getFilename();
1609    else
1610      O << "<unknown>";
1611    O << ':' << DLT.getLineNumber();
1612    if (DLT.getColumnNumber() != 0)
1613      O << ':' << DLT.getColumnNumber();
1614    Newline = true;
1615  }
1616
1617  // Check for spills and reloads
1618  int FI;
1619
1620  const MachineFrameInfo *FrameInfo =
1621    MI.getParent()->getParent()->getFrameInfo();
1622
1623  // We assume a single instruction only has a spill or reload, not
1624  // both.
1625  const MachineMemOperand *MMO;
1626  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1627    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1628      MMO = *MI.memoperands_begin();
1629      if (Newline) O << '\n';
1630      O.PadToColumn(MAI->getCommentColumn());
1631      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload";
1632      Newline = true;
1633    }
1634  }
1635  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1636    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1637      if (Newline) O << '\n';
1638      O.PadToColumn(MAI->getCommentColumn());
1639      O << MAI->getCommentString() << ' '
1640        << MMO->getSize() << "-byte Folded Reload";
1641      Newline = true;
1642    }
1643  }
1644  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1645    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1646      MMO = *MI.memoperands_begin();
1647      if (Newline) O << '\n';
1648      O.PadToColumn(MAI->getCommentColumn());
1649      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill";
1650      Newline = true;
1651    }
1652  }
1653  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1654    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1655      if (Newline) O << '\n';
1656      O.PadToColumn(MAI->getCommentColumn());
1657      O << MAI->getCommentString() << ' '
1658        << MMO->getSize() << "-byte Folded Spill";
1659      Newline = true;
1660    }
1661  }
1662
1663  // Check for spill-induced copies
1664  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1665  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1666                                      SrcSubIdx, DstSubIdx)) {
1667    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1668      if (Newline) O << '\n';
1669      O.PadToColumn(MAI->getCommentColumn());
1670      O << MAI->getCommentString() << " Reload Reuse";
1671    }
1672  }
1673}
1674
1675