AsmPrinter.cpp revision dc091da21df4460d274807b0357f41c103f1b904 
1//===-- AsmPrinter.cpp - Common AsmPrinter code ---------------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file implements the AsmPrinter class.
11//
12//===----------------------------------------------------------------------===//
13
14#define DEBUG_TYPE "asm-printer"
15#include "llvm/CodeGen/AsmPrinter.h"
16#include "llvm/Assembly/Writer.h"
17#include "llvm/DerivedTypes.h"
18#include "llvm/Constants.h"
19#include "llvm/Module.h"
20#include "llvm/CodeGen/DwarfWriter.h"
21#include "llvm/CodeGen/GCMetadataPrinter.h"
22#include "llvm/CodeGen/MachineConstantPool.h"
23#include "llvm/CodeGen/MachineFrameInfo.h"
24#include "llvm/CodeGen/MachineFunction.h"
25#include "llvm/CodeGen/MachineJumpTableInfo.h"
26#include "llvm/CodeGen/MachineLoopInfo.h"
27#include "llvm/CodeGen/MachineModuleInfo.h"
28#include "llvm/Analysis/DebugInfo.h"
29#include "llvm/MC/MCContext.h"
30#include "llvm/MC/MCExpr.h"
31#include "llvm/MC/MCInst.h"
32#include "llvm/MC/MCSection.h"
33#include "llvm/MC/MCStreamer.h"
34#include "llvm/MC/MCSymbol.h"
35#include "llvm/MC/MCAsmInfo.h"
36#include "llvm/Target/Mangler.h"
37#include "llvm/Target/TargetData.h"
38#include "llvm/Target/TargetInstrInfo.h"
39#include "llvm/Target/TargetLowering.h"
40#include "llvm/Target/TargetLoweringObjectFile.h"
41#include "llvm/Target/TargetOptions.h"
42#include "llvm/Target/TargetRegisterInfo.h"
43#include "llvm/ADT/SmallPtrSet.h"
44#include "llvm/ADT/SmallString.h"
45#include "llvm/ADT/Statistic.h"
46#include "llvm/Support/CommandLine.h"
47#include "llvm/Support/Debug.h"
48#include "llvm/Support/ErrorHandling.h"
49#include "llvm/Support/Format.h"
50#include "llvm/Support/FormattedStream.h"
51#include <cerrno>
52using namespace llvm;
53
54STATISTIC(EmittedInsts, "Number of machine instrs printed");
55
56char AsmPrinter::ID = 0;
57AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
58                       MCContext &Ctx, MCStreamer &Streamer,
59                       const MCAsmInfo *T)
60  : MachineFunctionPass(&ID), O(o),
61    TM(tm), MAI(T), TRI(tm.getRegisterInfo()),
62    OutContext(Ctx), OutStreamer(Streamer),
63    LastMI(0), LastFn(0), Counter(~0U), PrevDLT(NULL) {
64  DW = 0; MMI = 0;
65  VerboseAsm = Streamer.isVerboseAsm();
66}
67
68AsmPrinter::~AsmPrinter() {
69  for (gcp_iterator I = GCMetadataPrinters.begin(),
70                    E = GCMetadataPrinters.end(); I != E; ++I)
71    delete I->second;
72
73  delete &OutStreamer;
74  delete &OutContext;
75}
76
77/// getFunctionNumber - Return a unique ID for the current function.
78///
79unsigned AsmPrinter::getFunctionNumber() const {
80  return MF->getFunctionNumber();
81}
82
83TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
84  return TM.getTargetLowering()->getObjFileLowering();
85}
86
87/// getCurrentSection() - Return the current section we are emitting to.
88const MCSection *AsmPrinter::getCurrentSection() const {
89  return OutStreamer.getCurrentSection();
90}
91
92
93void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
94  AU.setPreservesAll();
95  MachineFunctionPass::getAnalysisUsage(AU);
96  AU.addRequired<GCModuleInfo>();
97  if (VerboseAsm)
98    AU.addRequired<MachineLoopInfo>();
99}
100
101bool AsmPrinter::doInitialization(Module &M) {
102  // Initialize TargetLoweringObjectFile.
103  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
104    .Initialize(OutContext, TM);
105
106  Mang = new Mangler(*MAI);
107
108  // Allow the target to emit any magic that it wants at the start of the file.
109  EmitStartOfAsmFile(M);
110
111  // Very minimal debug info. It is ignored if we emit actual debug info. If we
112  // don't, this at least helps the user find where a global came from.
113  if (MAI->hasSingleParameterDotFile()) {
114    // .file "foo.c"
115    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
116  }
117
118  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
119  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
120  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
121    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
122      MP->beginAssembly(O, *this, *MAI);
123
124  if (!M.getModuleInlineAsm().empty())
125    O << MAI->getCommentString() << " Start of file scope inline assembly\n"
126      << M.getModuleInlineAsm()
127      << '\n' << MAI->getCommentString()
128      << " End of file scope inline assembly\n";
129
130  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
131  if (MMI)
132    MMI->AnalyzeModule(M);
133  DW = getAnalysisIfAvailable<DwarfWriter>();
134  if (DW)
135    DW->BeginModule(&M, MMI, O, this, MAI);
136
137  return false;
138}
139
140void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
141  switch ((GlobalValue::LinkageTypes)Linkage) {
142  case GlobalValue::CommonLinkage:
143  case GlobalValue::LinkOnceAnyLinkage:
144  case GlobalValue::LinkOnceODRLinkage:
145  case GlobalValue::WeakAnyLinkage:
146  case GlobalValue::WeakODRLinkage:
147  case GlobalValue::LinkerPrivateLinkage:
148    if (MAI->getWeakDefDirective() != 0) {
149      // .globl _foo
150      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
151      // .weak_definition _foo
152      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
153    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
154      // .globl _foo
155      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
156      // FIXME: linkonce should be a section attribute, handled by COFF Section
157      // assignment.
158      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
159      // .linkonce discard
160      // FIXME: It would be nice to use .linkonce samesize for non-common
161      // globals.
162      O << LinkOnce;
163    } else {
164      // .weak _foo
165      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
166    }
167    break;
168  case GlobalValue::DLLExportLinkage:
169  case GlobalValue::AppendingLinkage:
170    // FIXME: appending linkage variables should go into a section of
171    // their name or something.  For now, just emit them as external.
172  case GlobalValue::ExternalLinkage:
173    // If external or appending, declare as a global symbol.
174    // .globl _foo
175    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
176    break;
177  case GlobalValue::PrivateLinkage:
178  case GlobalValue::InternalLinkage:
179    break;
180  default:
181    llvm_unreachable("Unknown linkage type!");
182  }
183}
184
185
186/// EmitGlobalVariable - Emit the specified global variable to the .s file.
187void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
188  if (!GV->hasInitializer())   // External globals require no code.
189    return;
190
191  // Check to see if this is a special global used by LLVM, if so, emit it.
192  if (EmitSpecialLLVMGlobal(GV))
193    return;
194
195  MCSymbol *GVSym = GetGlobalValueSymbol(GV);
196  EmitVisibility(GVSym, GV->getVisibility());
197
198  if (MAI->hasDotTypeDotSizeDirective())
199    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
200
201  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
202
203  const TargetData *TD = TM.getTargetData();
204  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
205  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
206
207  // Handle common and BSS local symbols (.lcomm).
208  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
209    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
210
211    if (VerboseAsm) {
212      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
213                     /*PrintType=*/false, GV->getParent());
214      OutStreamer.GetCommentOS() << '\n';
215    }
216
217    // Handle common symbols.
218    if (GVKind.isCommon()) {
219      // .comm _foo, 42, 4
220      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
221      return;
222    }
223
224    // Handle local BSS symbols.
225    if (MAI->hasMachoZeroFillDirective()) {
226      const MCSection *TheSection =
227        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
228      // .zerofill __DATA, __bss, _foo, 400, 5
229      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
230      return;
231    }
232
233    if (MAI->hasLCOMMDirective()) {
234      // .lcomm _foo, 42
235      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
236      return;
237    }
238
239    // .local _foo
240    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
241    // .comm _foo, 42, 4
242    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
243    return;
244  }
245
246  const MCSection *TheSection =
247    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
248
249  // Handle the zerofill directive on darwin, which is a special form of BSS
250  // emission.
251  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
252    // .globl _foo
253    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
254    // .zerofill __DATA, __common, _foo, 400, 5
255    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
256    return;
257  }
258
259  OutStreamer.SwitchSection(TheSection);
260
261  EmitLinkage(GV->getLinkage(), GVSym);
262  EmitAlignment(AlignLog, GV);
263
264  if (VerboseAsm) {
265    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
266                   /*PrintType=*/false, GV->getParent());
267    OutStreamer.GetCommentOS() << '\n';
268  }
269  OutStreamer.EmitLabel(GVSym);
270
271  EmitGlobalConstant(GV->getInitializer());
272
273  if (MAI->hasDotTypeDotSizeDirective())
274    // .size foo, 42
275    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
276
277  OutStreamer.AddBlankLine();
278}
279
280/// EmitFunctionHeader - This method emits the header for the current
281/// function.
282void AsmPrinter::EmitFunctionHeader() {
283  // Print out constants referenced by the function
284  EmitConstantPool();
285
286  // Print the 'header' of function.
287  const Function *F = MF->getFunction();
288
289  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
290  EmitVisibility(CurrentFnSym, F->getVisibility());
291
292  EmitLinkage(F->getLinkage(), CurrentFnSym);
293  EmitAlignment(MF->getAlignment(), F);
294
295  if (MAI->hasDotTypeDotSizeDirective())
296    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
297
298  if (VerboseAsm) {
299    WriteAsOperand(OutStreamer.GetCommentOS(), F,
300                   /*PrintType=*/false, F->getParent());
301    OutStreamer.GetCommentOS() << '\n';
302  }
303
304  // Emit the CurrentFnSym.  This is is a virtual function to allow targets to
305  // do their wild and crazy things as required.
306  EmitFunctionEntryLabel();
307
308  // Add some workaround for linkonce linkage on Cygwin\MinGW.
309  if (MAI->getLinkOnceDirective() != 0 &&
310      (F->hasLinkOnceLinkage() || F->hasWeakLinkage()))
311    // FIXME: What is this?
312    O << "Lllvm$workaround$fake$stub$" << *CurrentFnSym << ":\n";
313
314  // Emit pre-function debug and/or EH information.
315  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
316    DW->BeginFunction(MF);
317}
318
319/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
320/// function.  This can be overridden by targets as required to do custom stuff.
321void AsmPrinter::EmitFunctionEntryLabel() {
322  OutStreamer.EmitLabel(CurrentFnSym);
323}
324
325
326/// EmitFunctionBody - This method emits the body and trailer for a
327/// function.
328void AsmPrinter::EmitFunctionBody() {
329  // Emit target-specific gunk before the function body.
330  EmitFunctionBodyStart();
331
332  // Print out code for the function.
333  bool HasAnyRealCode = false;
334  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
335       I != E; ++I) {
336    // Print a label for the basic block.
337    EmitBasicBlockStart(I);
338    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
339         II != IE; ++II) {
340      // Print the assembly for the instruction.
341      if (!II->isLabel())
342        HasAnyRealCode = true;
343
344      ++EmittedInsts;
345
346      // FIXME: Clean up processDebugLoc.
347      processDebugLoc(II, true);
348
349      switch (II->getOpcode()) {
350      case TargetInstrInfo::DBG_LABEL:
351      case TargetInstrInfo::EH_LABEL:
352      case TargetInstrInfo::GC_LABEL:
353        printLabelInst(II);
354        break;
355      case TargetInstrInfo::INLINEASM:
356        printInlineAsm(II);
357        break;
358      case TargetInstrInfo::IMPLICIT_DEF:
359        printImplicitDef(II);
360        break;
361      case TargetInstrInfo::KILL:
362        printKill(II);
363        break;
364      default:
365        EmitInstruction(II);
366        break;
367      }
368      if (VerboseAsm)
369        EmitComments(*II);
370
371      // FIXME: Clean up processDebugLoc.
372      processDebugLoc(II, false);
373    }
374  }
375
376  // If the function is empty and the object file uses .subsections_via_symbols,
377  // then we need to emit *something* to the function body to prevent the
378  // labels from collapsing together.  Just emit a 0 byte.
379  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
380    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
381
382  // Emit target-specific gunk after the function body.
383  EmitFunctionBodyEnd();
384
385  if (MAI->hasDotTypeDotSizeDirective())
386    O << "\t.size\t" << *CurrentFnSym << ", .-" << *CurrentFnSym << '\n';
387
388  // Emit post-function debug information.
389  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
390    DW->EndFunction(MF);
391
392  // Print out jump tables referenced by the function.
393  EmitJumpTableInfo();
394}
395
396
397bool AsmPrinter::doFinalization(Module &M) {
398  // Emit global variables.
399  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
400       I != E; ++I)
401    EmitGlobalVariable(I);
402
403  // Emit final debug information.
404  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
405    DW->EndModule();
406
407  // If the target wants to know about weak references, print them all.
408  if (MAI->getWeakRefDirective()) {
409    // FIXME: This is not lazy, it would be nice to only print weak references
410    // to stuff that is actually used.  Note that doing so would require targets
411    // to notice uses in operands (due to constant exprs etc).  This should
412    // happen with the MC stuff eventually.
413
414    // Print out module-level global variables here.
415    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
416         I != E; ++I) {
417      if (!I->hasExternalWeakLinkage()) continue;
418      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
419                                      MCSA_WeakReference);
420    }
421
422    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
423      if (!I->hasExternalWeakLinkage()) continue;
424      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(I),
425                                      MCSA_WeakReference);
426    }
427  }
428
429  if (MAI->hasSetDirective()) {
430    OutStreamer.AddBlankLine();
431    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
432         I != E; ++I) {
433      MCSymbol *Name = GetGlobalValueSymbol(I);
434
435      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
436      MCSymbol *Target = GetGlobalValueSymbol(GV);
437
438      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
439        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
440      else if (I->hasWeakLinkage())
441        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
442      else
443        assert(I->hasLocalLinkage() && "Invalid alias linkage");
444
445      EmitVisibility(Name, I->getVisibility());
446
447      // Emit the directives as assignments aka .set:
448      OutStreamer.EmitAssignment(Name,
449                                 MCSymbolRefExpr::Create(Target, OutContext));
450    }
451  }
452
453  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
454  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
455  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
456    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
457      MP->finishAssembly(O, *this, *MAI);
458
459  // If we don't have any trampolines, then we don't require stack memory
460  // to be executable. Some targets have a directive to declare this.
461  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
462  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
463    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
464      OutStreamer.SwitchSection(S);
465
466  // Allow the target to emit any magic that it wants at the end of the file,
467  // after everything else has gone out.
468  EmitEndOfAsmFile(M);
469
470  delete Mang; Mang = 0;
471  DW = 0; MMI = 0;
472
473  OutStreamer.Finish();
474  return false;
475}
476
477void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
478  this->MF = &MF;
479  // Get the function symbol.
480  CurrentFnSym = GetGlobalValueSymbol(MF.getFunction());
481
482  if (VerboseAsm)
483    LI = &getAnalysis<MachineLoopInfo>();
484}
485
486namespace {
487  // SectionCPs - Keep track the alignment, constpool entries per Section.
488  struct SectionCPs {
489    const MCSection *S;
490    unsigned Alignment;
491    SmallVector<unsigned, 4> CPEs;
492    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
493  };
494}
495
496/// EmitConstantPool - Print to the current output stream assembly
497/// representations of the constants in the constant pool MCP. This is
498/// used to print out constants which have been "spilled to memory" by
499/// the code generator.
500///
501void AsmPrinter::EmitConstantPool() {
502  const MachineConstantPool *MCP = MF->getConstantPool();
503  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
504  if (CP.empty()) return;
505
506  // Calculate sections for constant pool entries. We collect entries to go into
507  // the same section together to reduce amount of section switch statements.
508  SmallVector<SectionCPs, 4> CPSections;
509  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
510    const MachineConstantPoolEntry &CPE = CP[i];
511    unsigned Align = CPE.getAlignment();
512
513    SectionKind Kind;
514    switch (CPE.getRelocationInfo()) {
515    default: llvm_unreachable("Unknown section kind");
516    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
517    case 1:
518      Kind = SectionKind::getReadOnlyWithRelLocal();
519      break;
520    case 0:
521    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
522    case 4:  Kind = SectionKind::getMergeableConst4(); break;
523    case 8:  Kind = SectionKind::getMergeableConst8(); break;
524    case 16: Kind = SectionKind::getMergeableConst16();break;
525    default: Kind = SectionKind::getMergeableConst(); break;
526    }
527    }
528
529    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
530
531    // The number of sections are small, just do a linear search from the
532    // last section to the first.
533    bool Found = false;
534    unsigned SecIdx = CPSections.size();
535    while (SecIdx != 0) {
536      if (CPSections[--SecIdx].S == S) {
537        Found = true;
538        break;
539      }
540    }
541    if (!Found) {
542      SecIdx = CPSections.size();
543      CPSections.push_back(SectionCPs(S, Align));
544    }
545
546    if (Align > CPSections[SecIdx].Alignment)
547      CPSections[SecIdx].Alignment = Align;
548    CPSections[SecIdx].CPEs.push_back(i);
549  }
550
551  // Now print stuff into the calculated sections.
552  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
553    OutStreamer.SwitchSection(CPSections[i].S);
554    EmitAlignment(Log2_32(CPSections[i].Alignment));
555
556    unsigned Offset = 0;
557    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
558      unsigned CPI = CPSections[i].CPEs[j];
559      MachineConstantPoolEntry CPE = CP[CPI];
560
561      // Emit inter-object padding for alignment.
562      unsigned AlignMask = CPE.getAlignment() - 1;
563      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
564      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
565
566      const Type *Ty = CPE.getType();
567      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
568
569      // Emit the label with a comment on it.
570      if (VerboseAsm) {
571        OutStreamer.GetCommentOS() << "constant pool ";
572        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
573                          MF->getFunction()->getParent());
574        OutStreamer.GetCommentOS() << '\n';
575      }
576      OutStreamer.EmitLabel(GetCPISymbol(CPI));
577
578      if (CPE.isMachineConstantPoolEntry())
579        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
580      else
581        EmitGlobalConstant(CPE.Val.ConstVal);
582    }
583  }
584}
585
586/// EmitJumpTableInfo - Print assembly representations of the jump tables used
587/// by the current function to the current output stream.
588///
589void AsmPrinter::EmitJumpTableInfo() {
590  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
591  if (MJTI == 0) return;
592  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
593  if (JT.empty()) return;
594
595  // Pick the directive to use to print the jump table entries, and switch to
596  // the appropriate section.
597  const Function *F = MF->getFunction();
598  bool JTInDiffSection = false;
599  if (// In PIC mode, we need to emit the jump table to the same section as the
600      // function body itself, otherwise the label differences won't make sense.
601      // FIXME: Need a better predicate for this: what about custom entries?
602      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
603      // We should also do if the section name is NULL or function is declared
604      // in discardable section
605      // FIXME: this isn't the right predicate, should be based on the MCSection
606      // for the function.
607      F->isWeakForLinker()) {
608    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
609  } else {
610    // Otherwise, drop it in the readonly section.
611    const MCSection *ReadOnlySection =
612      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
613    OutStreamer.SwitchSection(ReadOnlySection);
614    JTInDiffSection = true;
615  }
616
617  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
618
619  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
620    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
621
622    // If this jump table was deleted, ignore it.
623    if (JTBBs.empty()) continue;
624
625    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
626    // .set directive for each unique entry.  This reduces the number of
627    // relocations the assembler will generate for the jump table.
628    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
629        MAI->hasSetDirective()) {
630      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
631      const TargetLowering *TLI = TM.getTargetLowering();
632      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
633      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
634        const MachineBasicBlock *MBB = JTBBs[ii];
635        if (!EmittedSets.insert(MBB)) continue;
636
637        // .set LJTSet, LBB32-base
638        const MCExpr *LHS =
639          MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
640        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
641                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
642      }
643    }
644
645    // On some targets (e.g. Darwin) we want to emit two consequtive labels
646    // before each jump table.  The first label is never referenced, but tells
647    // the assembler and linker the extents of the jump table object.  The
648    // second label is actually referenced by the code.
649    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
650      // FIXME: This doesn't have to have any specific name, just any randomly
651      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
652      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
653
654    OutStreamer.EmitLabel(GetJTISymbol(JTI));
655
656    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
657      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
658  }
659}
660
661/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
662/// current stream.
663void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
664                                    const MachineBasicBlock *MBB,
665                                    unsigned UID) const {
666  const MCExpr *Value = 0;
667  switch (MJTI->getEntryKind()) {
668  case MachineJumpTableInfo::EK_Custom32:
669    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
670                                                              OutContext);
671    break;
672  case MachineJumpTableInfo::EK_BlockAddress:
673    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
674    //     .word LBB123
675    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
676    break;
677  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
678    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
679    // with a relocation as gp-relative, e.g.:
680    //     .gprel32 LBB123
681    MCSymbol *MBBSym = MBB->getSymbol(OutContext);
682    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
683    return;
684  }
685
686  case MachineJumpTableInfo::EK_LabelDifference32: {
687    // EK_LabelDifference32 - Each entry is the address of the block minus
688    // the address of the jump table.  This is used for PIC jump tables where
689    // gprel32 is not supported.  e.g.:
690    //      .word LBB123 - LJTI1_2
691    // If the .set directive is supported, this is emitted as:
692    //      .set L4_5_set_123, LBB123 - LJTI1_2
693    //      .word L4_5_set_123
694
695    // If we have emitted set directives for the jump table entries, print
696    // them rather than the entries themselves.  If we're emitting PIC, then
697    // emit the table entries as differences between two text section labels.
698    if (MAI->hasSetDirective()) {
699      // If we used .set, reference the .set's symbol.
700      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
701                                      OutContext);
702      break;
703    }
704    // Otherwise, use the difference as the jump table entry.
705    Value = MCSymbolRefExpr::Create(MBB->getSymbol(OutContext), OutContext);
706    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
707    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
708    break;
709  }
710  }
711
712  assert(Value && "Unknown entry kind!");
713
714  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
715  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
716}
717
718
719/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
720/// special global used by LLVM.  If so, emit it and return true, otherwise
721/// do nothing and return false.
722bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
723  if (GV->getName() == "llvm.used") {
724    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
725      EmitLLVMUsedList(GV->getInitializer());
726    return true;
727  }
728
729  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
730  if (GV->getSection() == "llvm.metadata" ||
731      GV->hasAvailableExternallyLinkage())
732    return true;
733
734  if (!GV->hasAppendingLinkage()) return false;
735
736  assert(GV->hasInitializer() && "Not a special LLVM global!");
737
738  const TargetData *TD = TM.getTargetData();
739  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
740  if (GV->getName() == "llvm.global_ctors") {
741    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
742    EmitAlignment(Align, 0);
743    EmitXXStructorList(GV->getInitializer());
744
745    if (TM.getRelocationModel() == Reloc::Static &&
746        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
747      StringRef Sym(".constructors_used");
748      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
749                                      MCSA_Reference);
750    }
751    return true;
752  }
753
754  if (GV->getName() == "llvm.global_dtors") {
755    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
756    EmitAlignment(Align, 0);
757    EmitXXStructorList(GV->getInitializer());
758
759    if (TM.getRelocationModel() == Reloc::Static &&
760        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
761      StringRef Sym(".destructors_used");
762      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
763                                      MCSA_Reference);
764    }
765    return true;
766  }
767
768  return false;
769}
770
771/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
772/// global in the specified llvm.used list for which emitUsedDirectiveFor
773/// is true, as being used with this directive.
774void AsmPrinter::EmitLLVMUsedList(Constant *List) {
775  // Should be an array of 'i8*'.
776  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
777  if (InitList == 0) return;
778
779  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
780    const GlobalValue *GV =
781      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
782    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
783      OutStreamer.EmitSymbolAttribute(GetGlobalValueSymbol(GV),
784                                      MCSA_NoDeadStrip);
785  }
786}
787
788/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
789/// function pointers, ignoring the init priority.
790void AsmPrinter::EmitXXStructorList(Constant *List) {
791  // Should be an array of '{ int, void ()* }' structs.  The first value is the
792  // init priority, which we ignore.
793  if (!isa<ConstantArray>(List)) return;
794  ConstantArray *InitList = cast<ConstantArray>(List);
795  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
796    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
797      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
798
799      if (CS->getOperand(1)->isNullValue())
800        return;  // Found a null terminator, exit printing.
801      // Emit the function pointer.
802      EmitGlobalConstant(CS->getOperand(1));
803    }
804}
805
806//===--------------------------------------------------------------------===//
807// Emission and print routines
808//
809
810/// EmitInt8 - Emit a byte directive and value.
811///
812void AsmPrinter::EmitInt8(int Value) const {
813  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
814}
815
816/// EmitInt16 - Emit a short directive and value.
817///
818void AsmPrinter::EmitInt16(int Value) const {
819  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
820}
821
822/// EmitInt32 - Emit a long directive and value.
823///
824void AsmPrinter::EmitInt32(int Value) const {
825  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
826}
827
828/// EmitInt64 - Emit a long long directive and value.
829///
830void AsmPrinter::EmitInt64(uint64_t Value) const {
831  OutStreamer.EmitIntValue(Value, 8, 0/*addrspace*/);
832}
833
834//===----------------------------------------------------------------------===//
835
836// EmitAlignment - Emit an alignment directive to the specified power of
837// two boundary.  For example, if you pass in 3 here, you will get an 8
838// byte alignment.  If a global value is specified, and if that global has
839// an explicit alignment requested, it will unconditionally override the
840// alignment request.  However, if ForcedAlignBits is specified, this value
841// has final say: the ultimate alignment will be the max of ForcedAlignBits
842// and the alignment computed with NumBits and the global.
843//
844// The algorithm is:
845//     Align = NumBits;
846//     if (GV && GV->hasalignment) Align = GV->getalignment();
847//     Align = std::max(Align, ForcedAlignBits);
848//
849void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
850                               unsigned ForcedAlignBits,
851                               bool UseFillExpr) const {
852  if (GV && GV->getAlignment())
853    NumBits = Log2_32(GV->getAlignment());
854  NumBits = std::max(NumBits, ForcedAlignBits);
855
856  if (NumBits == 0) return;   // No need to emit alignment.
857
858  unsigned FillValue = 0;
859  if (getCurrentSection()->getKind().isText())
860    FillValue = MAI->getTextAlignFillValue();
861
862  OutStreamer.EmitValueToAlignment(1 << NumBits, FillValue, 1, 0);
863}
864
865/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
866///
867static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
868  MCContext &Ctx = AP.OutContext;
869
870  if (CV->isNullValue() || isa<UndefValue>(CV))
871    return MCConstantExpr::Create(0, Ctx);
872
873  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
874    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
875
876  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
877    return MCSymbolRefExpr::Create(AP.GetGlobalValueSymbol(GV), Ctx);
878  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
879    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
880
881  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
882  if (CE == 0) {
883    llvm_unreachable("Unknown constant value to lower!");
884    return MCConstantExpr::Create(0, Ctx);
885  }
886
887  switch (CE->getOpcode()) {
888  case Instruction::ZExt:
889  case Instruction::SExt:
890  case Instruction::FPTrunc:
891  case Instruction::FPExt:
892  case Instruction::UIToFP:
893  case Instruction::SIToFP:
894  case Instruction::FPToUI:
895  case Instruction::FPToSI:
896  default: llvm_unreachable("FIXME: Don't support this constant cast expr");
897  case Instruction::GetElementPtr: {
898    const TargetData &TD = *AP.TM.getTargetData();
899    // Generate a symbolic expression for the byte address
900    const Constant *PtrVal = CE->getOperand(0);
901    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
902    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
903                                         IdxVec.size());
904
905    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
906    if (Offset == 0)
907      return Base;
908
909    // Truncate/sext the offset to the pointer size.
910    if (TD.getPointerSizeInBits() != 64) {
911      int SExtAmount = 64-TD.getPointerSizeInBits();
912      Offset = (Offset << SExtAmount) >> SExtAmount;
913    }
914
915    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
916                                   Ctx);
917  }
918
919  case Instruction::Trunc:
920    // We emit the value and depend on the assembler to truncate the generated
921    // expression properly.  This is important for differences between
922    // blockaddress labels.  Since the two labels are in the same function, it
923    // is reasonable to treat their delta as a 32-bit value.
924    // FALL THROUGH.
925  case Instruction::BitCast:
926    return LowerConstant(CE->getOperand(0), AP);
927
928  case Instruction::IntToPtr: {
929    const TargetData &TD = *AP.TM.getTargetData();
930    // Handle casts to pointers by changing them into casts to the appropriate
931    // integer type.  This promotes constant folding and simplifies this code.
932    Constant *Op = CE->getOperand(0);
933    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
934                                      false/*ZExt*/);
935    return LowerConstant(Op, AP);
936  }
937
938  case Instruction::PtrToInt: {
939    const TargetData &TD = *AP.TM.getTargetData();
940    // Support only foldable casts to/from pointers that can be eliminated by
941    // changing the pointer to the appropriately sized integer type.
942    Constant *Op = CE->getOperand(0);
943    const Type *Ty = CE->getType();
944
945    const MCExpr *OpExpr = LowerConstant(Op, AP);
946
947    // We can emit the pointer value into this slot if the slot is an
948    // integer slot equal to the size of the pointer.
949    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
950      return OpExpr;
951
952    // Otherwise the pointer is smaller than the resultant integer, mask off
953    // the high bits so we are sure to get a proper truncation if the input is
954    // a constant expr.
955    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
956    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
957    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
958  }
959
960  case Instruction::Add:
961  case Instruction::Sub:
962  case Instruction::And:
963  case Instruction::Or:
964  case Instruction::Xor: {
965    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
966    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
967    switch (CE->getOpcode()) {
968    default: llvm_unreachable("Unknown binary operator constant cast expr");
969    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
970    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
971    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
972    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
973    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
974    }
975  }
976  }
977}
978
979static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
980                                    AsmPrinter &AP) {
981  if (AddrSpace != 0 || !CA->isString()) {
982    // Not a string.  Print the values in successive locations
983    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
984      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
985    return;
986  }
987
988  // Otherwise, it can be emitted as .ascii.
989  SmallVector<char, 128> TmpVec;
990  TmpVec.reserve(CA->getNumOperands());
991  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
992    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
993
994  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
995}
996
997static void EmitGlobalConstantVector(const ConstantVector *CV,
998                                     unsigned AddrSpace, AsmPrinter &AP) {
999  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1000    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1001}
1002
1003static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1004                                     unsigned AddrSpace, AsmPrinter &AP) {
1005  // Print the fields in successive locations. Pad to align if needed!
1006  const TargetData *TD = AP.TM.getTargetData();
1007  unsigned Size = TD->getTypeAllocSize(CS->getType());
1008  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1009  uint64_t SizeSoFar = 0;
1010  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1011    const Constant *Field = CS->getOperand(i);
1012
1013    // Check if padding is needed and insert one or more 0s.
1014    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1015    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1016                        - Layout->getElementOffset(i)) - FieldSize;
1017    SizeSoFar += FieldSize + PadSize;
1018
1019    // Now print the actual field value.
1020    AP.EmitGlobalConstant(Field, AddrSpace);
1021
1022    // Insert padding - this may include padding to increase the size of the
1023    // current field up to the ABI size (if the struct is not packed) as well
1024    // as padding to ensure that the next field starts at the right offset.
1025    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1026  }
1027  assert(SizeSoFar == Layout->getSizeInBytes() &&
1028         "Layout of constant struct may be incorrect!");
1029}
1030
1031static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1032                                 AsmPrinter &AP) {
1033  // FP Constants are printed as integer constants to avoid losing
1034  // precision.
1035  if (CFP->getType()->isDoubleTy()) {
1036    if (AP.VerboseAsm) {
1037      double Val = CFP->getValueAPF().convertToDouble();
1038      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1039    }
1040
1041    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1042    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1043    return;
1044  }
1045
1046  if (CFP->getType()->isFloatTy()) {
1047    if (AP.VerboseAsm) {
1048      float Val = CFP->getValueAPF().convertToFloat();
1049      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1050    }
1051    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1052    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1053    return;
1054  }
1055
1056  if (CFP->getType()->isX86_FP80Ty()) {
1057    // all long double variants are printed as hex
1058    // api needed to prevent premature destruction
1059    APInt API = CFP->getValueAPF().bitcastToAPInt();
1060    const uint64_t *p = API.getRawData();
1061    if (AP.VerboseAsm) {
1062      // Convert to double so we can print the approximate val as a comment.
1063      APFloat DoubleVal = CFP->getValueAPF();
1064      bool ignored;
1065      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1066                        &ignored);
1067      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1068        << DoubleVal.convertToDouble() << '\n';
1069    }
1070
1071    if (AP.TM.getTargetData()->isBigEndian()) {
1072      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1073      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1074    } else {
1075      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1076      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1077    }
1078
1079    // Emit the tail padding for the long double.
1080    const TargetData &TD = *AP.TM.getTargetData();
1081    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1082                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1083    return;
1084  }
1085
1086  assert(CFP->getType()->isPPC_FP128Ty() &&
1087         "Floating point constant type not handled");
1088  // All long double variants are printed as hex api needed to prevent
1089  // premature destruction.
1090  APInt API = CFP->getValueAPF().bitcastToAPInt();
1091  const uint64_t *p = API.getRawData();
1092  if (AP.TM.getTargetData()->isBigEndian()) {
1093    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1094    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1095  } else {
1096    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1097    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1098  }
1099}
1100
1101static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1102                                       unsigned AddrSpace, AsmPrinter &AP) {
1103  const TargetData *TD = AP.TM.getTargetData();
1104  unsigned BitWidth = CI->getBitWidth();
1105  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1106
1107  // We don't expect assemblers to support integer data directives
1108  // for more than 64 bits, so we emit the data in at most 64-bit
1109  // quantities at a time.
1110  const uint64_t *RawData = CI->getValue().getRawData();
1111  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1112    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1113    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1114  }
1115}
1116
1117/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1118void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1119  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1120    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1121    return OutStreamer.EmitZeros(Size, AddrSpace);
1122  }
1123
1124  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1125    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1126    switch (Size) {
1127    case 1:
1128    case 2:
1129    case 4:
1130    case 8:
1131      if (VerboseAsm)
1132        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1133      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1134      return;
1135    default:
1136      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1137      return;
1138    }
1139  }
1140
1141  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1142    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1143
1144  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1145    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1146
1147  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1148    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1149
1150  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1151    return EmitGlobalConstantVector(V, AddrSpace, *this);
1152
1153  if (isa<ConstantPointerNull>(CV)) {
1154    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1155    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1156    return;
1157  }
1158
1159  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1160  // thread the streamer with EmitValue.
1161  OutStreamer.EmitValue(LowerConstant(CV, *this),
1162                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1163                        AddrSpace);
1164}
1165
1166void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1167  // Target doesn't support this yet!
1168  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1169}
1170
1171/// PrintSpecial - Print information related to the specified machine instr
1172/// that is independent of the operand, and may be independent of the instr
1173/// itself.  This can be useful for portably encoding the comment character
1174/// or other bits of target-specific knowledge into the asmstrings.  The
1175/// syntax used is ${:comment}.  Targets can override this to add support
1176/// for their own strange codes.
1177void AsmPrinter::PrintSpecial(const MachineInstr *MI, const char *Code) const {
1178  if (!strcmp(Code, "private")) {
1179    O << MAI->getPrivateGlobalPrefix();
1180  } else if (!strcmp(Code, "comment")) {
1181    if (VerboseAsm)
1182      O << MAI->getCommentString();
1183  } else if (!strcmp(Code, "uid")) {
1184    // Comparing the address of MI isn't sufficient, because machineinstrs may
1185    // be allocated to the same address across functions.
1186    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1187
1188    // If this is a new LastFn instruction, bump the counter.
1189    if (LastMI != MI || LastFn != ThisF) {
1190      ++Counter;
1191      LastMI = MI;
1192      LastFn = ThisF;
1193    }
1194    O << Counter;
1195  } else {
1196    std::string msg;
1197    raw_string_ostream Msg(msg);
1198    Msg << "Unknown special formatter '" << Code
1199         << "' for machine instr: " << *MI;
1200    llvm_report_error(Msg.str());
1201  }
1202}
1203
1204/// processDebugLoc - Processes the debug information of each machine
1205/// instruction's DebugLoc.
1206void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1207                                 bool BeforePrintingInsn) {
1208  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1209      || !DW->ShouldEmitDwarfDebug())
1210    return;
1211  DebugLoc DL = MI->getDebugLoc();
1212  if (DL.isUnknown())
1213    return;
1214  DILocation CurDLT = MF->getDILocation(DL);
1215  if (CurDLT.getScope().isNull())
1216    return;
1217
1218  if (!BeforePrintingInsn) {
1219    // After printing instruction
1220    DW->EndScope(MI);
1221  } else if (CurDLT.getNode() != PrevDLT) {
1222    unsigned L = DW->RecordSourceLine(CurDLT.getLineNumber(),
1223                                      CurDLT.getColumnNumber(),
1224                                      CurDLT.getScope().getNode());
1225    printLabel(L);
1226    O << '\n';
1227    DW->BeginScope(MI, L);
1228    PrevDLT = CurDLT.getNode();
1229  }
1230}
1231
1232
1233/// printInlineAsm - This method formats and prints the specified machine
1234/// instruction that is an inline asm.
1235void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1236  unsigned NumOperands = MI->getNumOperands();
1237
1238  // Count the number of register definitions.
1239  unsigned NumDefs = 0;
1240  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1241       ++NumDefs)
1242    assert(NumDefs != NumOperands-1 && "No asm string?");
1243
1244  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1245
1246  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1247  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1248
1249  O << '\t';
1250
1251  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1252  // These are useful to see where empty asm's wound up.
1253  if (AsmStr[0] == 0) {
1254    O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1255    O << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1256    return;
1257  }
1258
1259  O << MAI->getCommentString() << MAI->getInlineAsmStart() << "\n\t";
1260
1261  // The variant of the current asmprinter.
1262  int AsmPrinterVariant = MAI->getAssemblerDialect();
1263
1264  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1265  const char *LastEmitted = AsmStr; // One past the last character emitted.
1266
1267  while (*LastEmitted) {
1268    switch (*LastEmitted) {
1269    default: {
1270      // Not a special case, emit the string section literally.
1271      const char *LiteralEnd = LastEmitted+1;
1272      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1273             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1274        ++LiteralEnd;
1275      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1276        O.write(LastEmitted, LiteralEnd-LastEmitted);
1277      LastEmitted = LiteralEnd;
1278      break;
1279    }
1280    case '\n':
1281      ++LastEmitted;   // Consume newline character.
1282      O << '\n';       // Indent code with newline.
1283      break;
1284    case '$': {
1285      ++LastEmitted;   // Consume '$' character.
1286      bool Done = true;
1287
1288      // Handle escapes.
1289      switch (*LastEmitted) {
1290      default: Done = false; break;
1291      case '$':     // $$ -> $
1292        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1293          O << '$';
1294        ++LastEmitted;  // Consume second '$' character.
1295        break;
1296      case '(':             // $( -> same as GCC's { character.
1297        ++LastEmitted;      // Consume '(' character.
1298        if (CurVariant != -1) {
1299          llvm_report_error("Nested variants found in inline asm string: '"
1300                            + std::string(AsmStr) + "'");
1301        }
1302        CurVariant = 0;     // We're in the first variant now.
1303        break;
1304      case '|':
1305        ++LastEmitted;  // consume '|' character.
1306        if (CurVariant == -1)
1307          O << '|';       // this is gcc's behavior for | outside a variant
1308        else
1309          ++CurVariant;   // We're in the next variant.
1310        break;
1311      case ')':         // $) -> same as GCC's } char.
1312        ++LastEmitted;  // consume ')' character.
1313        if (CurVariant == -1)
1314          O << '}';     // this is gcc's behavior for } outside a variant
1315        else
1316          CurVariant = -1;
1317        break;
1318      }
1319      if (Done) break;
1320
1321      bool HasCurlyBraces = false;
1322      if (*LastEmitted == '{') {     // ${variable}
1323        ++LastEmitted;               // Consume '{' character.
1324        HasCurlyBraces = true;
1325      }
1326
1327      // If we have ${:foo}, then this is not a real operand reference, it is a
1328      // "magic" string reference, just like in .td files.  Arrange to call
1329      // PrintSpecial.
1330      if (HasCurlyBraces && *LastEmitted == ':') {
1331        ++LastEmitted;
1332        const char *StrStart = LastEmitted;
1333        const char *StrEnd = strchr(StrStart, '}');
1334        if (StrEnd == 0) {
1335          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1336                            + std::string(AsmStr) + "'");
1337        }
1338
1339        std::string Val(StrStart, StrEnd);
1340        PrintSpecial(MI, Val.c_str());
1341        LastEmitted = StrEnd+1;
1342        break;
1343      }
1344
1345      const char *IDStart = LastEmitted;
1346      char *IDEnd;
1347      errno = 0;
1348      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1349      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1350        llvm_report_error("Bad $ operand number in inline asm string: '"
1351                          + std::string(AsmStr) + "'");
1352      }
1353      LastEmitted = IDEnd;
1354
1355      char Modifier[2] = { 0, 0 };
1356
1357      if (HasCurlyBraces) {
1358        // If we have curly braces, check for a modifier character.  This
1359        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1360        if (*LastEmitted == ':') {
1361          ++LastEmitted;    // Consume ':' character.
1362          if (*LastEmitted == 0) {
1363            llvm_report_error("Bad ${:} expression in inline asm string: '"
1364                              + std::string(AsmStr) + "'");
1365          }
1366
1367          Modifier[0] = *LastEmitted;
1368          ++LastEmitted;    // Consume modifier character.
1369        }
1370
1371        if (*LastEmitted != '}') {
1372          llvm_report_error("Bad ${} expression in inline asm string: '"
1373                            + std::string(AsmStr) + "'");
1374        }
1375        ++LastEmitted;    // Consume '}' character.
1376      }
1377
1378      if ((unsigned)Val >= NumOperands-1) {
1379        llvm_report_error("Invalid $ operand number in inline asm string: '"
1380                          + std::string(AsmStr) + "'");
1381      }
1382
1383      // Okay, we finally have a value number.  Ask the target to print this
1384      // operand!
1385      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1386        unsigned OpNo = 1;
1387
1388        bool Error = false;
1389
1390        // Scan to find the machine operand number for the operand.
1391        for (; Val; --Val) {
1392          if (OpNo >= MI->getNumOperands()) break;
1393          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1394          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1395        }
1396
1397        if (OpNo >= MI->getNumOperands()) {
1398          Error = true;
1399        } else {
1400          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1401          ++OpNo;  // Skip over the ID number.
1402
1403          if (Modifier[0] == 'l')  // labels are target independent
1404            O << *MI->getOperand(OpNo).getMBB()->getSymbol(OutContext);
1405          else {
1406            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1407            if ((OpFlags & 7) == 4) {
1408              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1409                                                Modifier[0] ? Modifier : 0);
1410            } else {
1411              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1412                                          Modifier[0] ? Modifier : 0);
1413            }
1414          }
1415        }
1416        if (Error) {
1417          std::string msg;
1418          raw_string_ostream Msg(msg);
1419          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1420          MI->print(Msg);
1421          llvm_report_error(Msg.str());
1422        }
1423      }
1424      break;
1425    }
1426    }
1427  }
1428  O << "\n\t" << MAI->getCommentString() << MAI->getInlineAsmEnd() << '\n';
1429}
1430
1431/// printImplicitDef - This method prints the specified machine instruction
1432/// that is an implicit def.
1433void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1434  if (!VerboseAsm) return;
1435  O.PadToColumn(MAI->getCommentColumn());
1436  O << MAI->getCommentString() << " implicit-def: "
1437    << TRI->getName(MI->getOperand(0).getReg()) << '\n';
1438}
1439
1440void AsmPrinter::printKill(const MachineInstr *MI) const {
1441  if (!VerboseAsm) return;
1442  O.PadToColumn(MAI->getCommentColumn());
1443  O << MAI->getCommentString() << " kill:";
1444  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1445    const MachineOperand &op = MI->getOperand(n);
1446    assert(op.isReg() && "KILL instruction must have only register operands");
1447    O << ' ' << TRI->getName(op.getReg()) << (op.isDef() ? "<def>" : "<kill>");
1448  }
1449  O << '\n';
1450}
1451
1452/// printLabel - This method prints a local label used by debug and
1453/// exception handling tables.
1454void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1455  printLabel(MI->getOperand(0).getImm());
1456  O << '\n';
1457}
1458
1459void AsmPrinter::printLabel(unsigned Id) const {
1460  O << MAI->getPrivateGlobalPrefix() << "label" << Id << ':';
1461}
1462
1463/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1464/// instruction, using the specified assembler variant.  Targets should
1465/// override this to format as appropriate.
1466bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1467                                 unsigned AsmVariant, const char *ExtraCode) {
1468  // Target doesn't support this yet!
1469  return true;
1470}
1471
1472bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1473                                       unsigned AsmVariant,
1474                                       const char *ExtraCode) {
1475  // Target doesn't support this yet!
1476  return true;
1477}
1478
1479MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA,
1480                                            const char *Suffix) const {
1481  return GetBlockAddressSymbol(BA->getFunction(), BA->getBasicBlock(), Suffix);
1482}
1483
1484MCSymbol *AsmPrinter::GetBlockAddressSymbol(const Function *F,
1485                                            const BasicBlock *BB,
1486                                            const char *Suffix) const {
1487  assert(BB->hasName() &&
1488         "Address of anonymous basic block not supported yet!");
1489
1490  // This code must use the function name itself, and not the function number,
1491  // since it must be possible to generate the label name from within other
1492  // functions.
1493  SmallString<60> FnName;
1494  Mang->getNameWithPrefix(FnName, F, false);
1495
1496  // FIXME: THIS IS BROKEN IF THE LLVM BASIC BLOCK DOESN'T HAVE A NAME!
1497  SmallString<60> NameResult;
1498  Mang->getNameWithPrefix(NameResult,
1499                          StringRef("BA") + Twine((unsigned)FnName.size()) +
1500                          "_" + FnName.str() + "_" + BB->getName() + Suffix,
1501                          Mangler::Private);
1502
1503  return OutContext.GetOrCreateSymbol(NameResult.str());
1504}
1505
1506/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1507MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1508  SmallString<60> Name;
1509  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix() << "CPI"
1510    << getFunctionNumber() << '_' << CPID;
1511  return OutContext.GetOrCreateSymbol(Name.str());
1512}
1513
1514/// GetJTISymbol - Return the symbol for the specified jump table entry.
1515MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1516  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1517}
1518
1519/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1520/// FIXME: privatize to AsmPrinter.
1521MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1522  SmallString<60> Name;
1523  raw_svector_ostream(Name) << MAI->getPrivateGlobalPrefix()
1524    << getFunctionNumber() << '_' << UID << "_set_" << MBBID;
1525  return OutContext.GetOrCreateSymbol(Name.str());
1526}
1527
1528/// GetGlobalValueSymbol - Return the MCSymbol for the specified global
1529/// value.
1530MCSymbol *AsmPrinter::GetGlobalValueSymbol(const GlobalValue *GV) const {
1531  SmallString<60> NameStr;
1532  Mang->getNameWithPrefix(NameStr, GV, false);
1533  return OutContext.GetOrCreateSymbol(NameStr.str());
1534}
1535
1536/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1537/// global value name as its base, with the specified suffix, and where the
1538/// symbol is forced to have private linkage if ForcePrivate is true.
1539MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1540                                                   StringRef Suffix,
1541                                                   bool ForcePrivate) const {
1542  SmallString<60> NameStr;
1543  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1544  NameStr.append(Suffix.begin(), Suffix.end());
1545  return OutContext.GetOrCreateSymbol(NameStr.str());
1546}
1547
1548/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1549/// ExternalSymbol.
1550MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1551  SmallString<60> NameStr;
1552  Mang->getNameWithPrefix(NameStr, Sym);
1553  return OutContext.GetOrCreateSymbol(NameStr.str());
1554}
1555
1556
1557
1558/// PrintParentLoopComment - Print comments about parent loops of this one.
1559static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1560                                   unsigned FunctionNumber) {
1561  if (Loop == 0) return;
1562  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1563  OS.indent(Loop->getLoopDepth()*2)
1564    << "Parent Loop BB" << FunctionNumber << "_"
1565    << Loop->getHeader()->getNumber()
1566    << " Depth=" << Loop->getLoopDepth() << '\n';
1567}
1568
1569
1570/// PrintChildLoopComment - Print comments about child loops within
1571/// the loop for this basic block, with nesting.
1572static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1573                                  unsigned FunctionNumber) {
1574  // Add child loop information
1575  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1576    OS.indent((*CL)->getLoopDepth()*2)
1577      << "Child Loop BB" << FunctionNumber << "_"
1578      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1579      << '\n';
1580    PrintChildLoopComment(OS, *CL, FunctionNumber);
1581  }
1582}
1583
1584/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1585static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1586                                        const MachineLoopInfo *LI,
1587                                        const AsmPrinter &AP) {
1588  // Add loop depth information
1589  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1590  if (Loop == 0) return;
1591
1592  MachineBasicBlock *Header = Loop->getHeader();
1593  assert(Header && "No header for loop");
1594
1595  // If this block is not a loop header, just print out what is the loop header
1596  // and return.
1597  if (Header != &MBB) {
1598    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1599                              Twine(AP.getFunctionNumber())+"_" +
1600                              Twine(Loop->getHeader()->getNumber())+
1601                              " Depth="+Twine(Loop->getLoopDepth()));
1602    return;
1603  }
1604
1605  // Otherwise, it is a loop header.  Print out information about child and
1606  // parent loops.
1607  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1608
1609  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1610
1611  OS << "=>";
1612  OS.indent(Loop->getLoopDepth()*2-2);
1613
1614  OS << "This ";
1615  if (Loop->empty())
1616    OS << "Inner ";
1617  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1618
1619  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1620}
1621
1622
1623/// EmitBasicBlockStart - This method prints the label for the specified
1624/// MachineBasicBlock, an alignment (if present) and a comment describing
1625/// it if appropriate.
1626void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1627  // Emit an alignment directive for this block, if needed.
1628  if (unsigned Align = MBB->getAlignment())
1629    EmitAlignment(Log2_32(Align));
1630
1631  // If the block has its address taken, emit a special label to satisfy
1632  // references to the block. This is done so that we don't need to
1633  // remember the number of this label, and so that we can make
1634  // forward references to labels without knowing what their numbers
1635  // will be.
1636  if (MBB->hasAddressTaken()) {
1637    const BasicBlock *BB = MBB->getBasicBlock();
1638    if (VerboseAsm)
1639      OutStreamer.AddComment("Address Taken");
1640    OutStreamer.EmitLabel(GetBlockAddressSymbol(BB->getParent(), BB));
1641  }
1642
1643  // Print the main label for the block.
1644  if (MBB->pred_empty() || MBB->isOnlyReachableByFallthrough()) {
1645    if (VerboseAsm) {
1646      // NOTE: Want this comment at start of line.
1647      O << MAI->getCommentString() << " BB#" << MBB->getNumber() << ':';
1648      if (const BasicBlock *BB = MBB->getBasicBlock())
1649        if (BB->hasName())
1650          OutStreamer.AddComment("%" + BB->getName());
1651
1652      PrintBasicBlockLoopComments(*MBB, LI, *this);
1653      OutStreamer.AddBlankLine();
1654    }
1655  } else {
1656    if (VerboseAsm) {
1657      if (const BasicBlock *BB = MBB->getBasicBlock())
1658        if (BB->hasName())
1659          OutStreamer.AddComment("%" + BB->getName());
1660      PrintBasicBlockLoopComments(*MBB, LI, *this);
1661    }
1662
1663    OutStreamer.EmitLabel(MBB->getSymbol(OutContext));
1664  }
1665}
1666
1667void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1668  MCSymbolAttr Attr = MCSA_Invalid;
1669
1670  switch (Visibility) {
1671  default: break;
1672  case GlobalValue::HiddenVisibility:
1673    Attr = MAI->getHiddenVisibilityAttr();
1674    break;
1675  case GlobalValue::ProtectedVisibility:
1676    Attr = MAI->getProtectedVisibilityAttr();
1677    break;
1678  }
1679
1680  if (Attr != MCSA_Invalid)
1681    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1682}
1683
1684void AsmPrinter::printOffset(int64_t Offset) const {
1685  if (Offset > 0)
1686    O << '+' << Offset;
1687  else if (Offset < 0)
1688    O << Offset;
1689}
1690
1691GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1692  if (!S->usesMetadata())
1693    return 0;
1694
1695  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1696  if (GCPI != GCMetadataPrinters.end())
1697    return GCPI->second;
1698
1699  const char *Name = S->getName().c_str();
1700
1701  for (GCMetadataPrinterRegistry::iterator
1702         I = GCMetadataPrinterRegistry::begin(),
1703         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1704    if (strcmp(Name, I->getName()) == 0) {
1705      GCMetadataPrinter *GMP = I->instantiate();
1706      GMP->S = S;
1707      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1708      return GMP;
1709    }
1710
1711  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1712  return 0;
1713}
1714
1715/// EmitComments - Pretty-print comments for instructions
1716void AsmPrinter::EmitComments(const MachineInstr &MI) const {
1717  if (!VerboseAsm)
1718    return;
1719
1720  if (!MI.getDebugLoc().isUnknown()) {
1721    DILocation DLT = MF->getDILocation(MI.getDebugLoc());
1722
1723    // Print source line info.
1724    O.PadToColumn(MAI->getCommentColumn());
1725    O << MAI->getCommentString() << ' ';
1726    DIScope Scope = DLT.getScope();
1727    // Omit the directory, because it's likely to be long and uninteresting.
1728    if (!Scope.isNull())
1729      O << Scope.getFilename();
1730    else
1731      O << "<unknown>";
1732    O << ':' << DLT.getLineNumber();
1733    if (DLT.getColumnNumber() != 0)
1734      O << ':' << DLT.getColumnNumber();
1735    O << '\n';
1736  }
1737
1738  // Check for spills and reloads
1739  int FI;
1740
1741  const MachineFrameInfo *FrameInfo =
1742    MI.getParent()->getParent()->getFrameInfo();
1743
1744  // We assume a single instruction only has a spill or reload, not
1745  // both.
1746  const MachineMemOperand *MMO;
1747  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
1748    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1749      MMO = *MI.memoperands_begin();
1750      O.PadToColumn(MAI->getCommentColumn());
1751      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Reload\n";
1752    }
1753  }
1754  else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
1755    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1756      O.PadToColumn(MAI->getCommentColumn());
1757      O << MAI->getCommentString() << ' '
1758        << MMO->getSize() << "-byte Folded Reload\n";
1759    }
1760  }
1761  else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
1762    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1763      MMO = *MI.memoperands_begin();
1764      O.PadToColumn(MAI->getCommentColumn());
1765      O << MAI->getCommentString() << ' ' << MMO->getSize() << "-byte Spill\n";
1766    }
1767  }
1768  else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
1769    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
1770      O.PadToColumn(MAI->getCommentColumn());
1771      O << MAI->getCommentString() << ' '
1772        << MMO->getSize() << "-byte Folded Spill\n";
1773    }
1774  }
1775
1776  // Check for spill-induced copies
1777  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
1778  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
1779                                      SrcSubIdx, DstSubIdx)) {
1780    if (MI.getAsmPrinterFlag(ReloadReuse)) {
1781      O.PadToColumn(MAI->getCommentColumn());
1782      O << MAI->getCommentString() << " Reload Reuse\n";
1783    }
1784  }
1785}
1786
1787