AsmPrinter.cpp revision fdc794a7f748a2b83c8a2e32378111785ad53146
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 "DwarfDebug.h"
17#include "DwarfException.h"
18#include "llvm/Module.h"
19#include "llvm/CodeGen/GCMetadataPrinter.h"
20#include "llvm/CodeGen/MachineConstantPool.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22#include "llvm/CodeGen/MachineFunction.h"
23#include "llvm/CodeGen/MachineJumpTableInfo.h"
24#include "llvm/CodeGen/MachineLoopInfo.h"
25#include "llvm/CodeGen/MachineModuleInfo.h"
26#include "llvm/Analysis/ConstantFolding.h"
27#include "llvm/Analysis/DebugInfo.h"
28#include "llvm/MC/MCAsmInfo.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/Target/Mangler.h"
36#include "llvm/Target/TargetData.h"
37#include "llvm/Target/TargetInstrInfo.h"
38#include "llvm/Target/TargetLowering.h"
39#include "llvm/Target/TargetLoweringObjectFile.h"
40#include "llvm/Target/TargetRegisterInfo.h"
41#include "llvm/ADT/SmallString.h"
42#include "llvm/ADT/Statistic.h"
43#include "llvm/Support/ErrorHandling.h"
44#include "llvm/Support/Format.h"
45#include "llvm/Support/Timer.h"
46using namespace llvm;
47
48static const char *DWARFGroupName = "DWARF Emission";
49static const char *DbgTimerName = "DWARF Debug Writer";
50static const char *EHTimerName = "DWARF Exception Writer";
51
52STATISTIC(EmittedInsts, "Number of machine instrs printed");
53
54char AsmPrinter::ID = 0;
55
56typedef DenseMap<GCStrategy*,GCMetadataPrinter*> gcp_map_type;
57static gcp_map_type &getGCMap(void *&P) {
58  if (P == 0)
59    P = new gcp_map_type();
60  return *(gcp_map_type*)P;
61}
62
63
64/// getGVAlignmentLog2 - Return the alignment to use for the specified global
65/// value in log2 form.  This rounds up to the preferred alignment if possible
66/// and legal.
67static unsigned getGVAlignmentLog2(const GlobalValue *GV, const TargetData &TD,
68                                   unsigned InBits = 0) {
69  unsigned NumBits = 0;
70  if (const GlobalVariable *GVar = dyn_cast<GlobalVariable>(GV))
71    NumBits = TD.getPreferredAlignmentLog(GVar);
72
73  // If InBits is specified, round it to it.
74  if (InBits > NumBits)
75    NumBits = InBits;
76
77  // If the GV has a specified alignment, take it into account.
78  if (GV->getAlignment() == 0)
79    return NumBits;
80
81  unsigned GVAlign = Log2_32(GV->getAlignment());
82
83  // If the GVAlign is larger than NumBits, or if we are required to obey
84  // NumBits because the GV has an assigned section, obey it.
85  if (GVAlign > NumBits || GV->hasSection())
86    NumBits = GVAlign;
87  return NumBits;
88}
89
90
91
92
93AsmPrinter::AsmPrinter(TargetMachine &tm, MCStreamer &Streamer)
94  : MachineFunctionPass(&ID),
95    TM(tm), MAI(tm.getMCAsmInfo()),
96    OutContext(Streamer.getContext()),
97    OutStreamer(Streamer),
98    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
99  DD = 0; DE = 0; MMI = 0; LI = 0;
100  GCMetadataPrinters = 0;
101  VerboseAsm = Streamer.isVerboseAsm();
102}
103
104AsmPrinter::~AsmPrinter() {
105  assert(DD == 0 && DE == 0 && "Debug/EH info didn't get finalized");
106
107  if (GCMetadataPrinters != 0) {
108    gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
109
110    for (gcp_map_type::iterator I = GCMap.begin(), E = GCMap.end(); I != E; ++I)
111      delete I->second;
112    delete &GCMap;
113    GCMetadataPrinters = 0;
114  }
115
116  delete &OutStreamer;
117}
118
119/// getFunctionNumber - Return a unique ID for the current function.
120///
121unsigned AsmPrinter::getFunctionNumber() const {
122  return MF->getFunctionNumber();
123}
124
125const TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
126  return TM.getTargetLowering()->getObjFileLowering();
127}
128
129
130/// getTargetData - Return information about data layout.
131const TargetData &AsmPrinter::getTargetData() const {
132  return *TM.getTargetData();
133}
134
135/// getCurrentSection() - Return the current section we are emitting to.
136const MCSection *AsmPrinter::getCurrentSection() const {
137  return OutStreamer.getCurrentSection();
138}
139
140
141
142void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
143  AU.setPreservesAll();
144  MachineFunctionPass::getAnalysisUsage(AU);
145  AU.addRequired<MachineModuleInfo>();
146  AU.addRequired<GCModuleInfo>();
147  if (isVerbose())
148    AU.addRequired<MachineLoopInfo>();
149}
150
151bool AsmPrinter::doInitialization(Module &M) {
152  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
153  MMI->AnalyzeModule(M);
154
155  // Initialize TargetLoweringObjectFile.
156  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
157    .Initialize(OutContext, TM);
158
159  Mang = new Mangler(OutContext, *TM.getTargetData());
160
161  // Allow the target to emit any magic that it wants at the start of the file.
162  EmitStartOfAsmFile(M);
163
164  // Very minimal debug info. It is ignored if we emit actual debug info. If we
165  // don't, this at least helps the user find where a global came from.
166  if (MAI->hasSingleParameterDotFile()) {
167    // .file "foo.c"
168    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
169  }
170
171  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
172  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
173  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
174    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
175      MP->beginAssembly(*this);
176
177  // Emit module-level inline asm if it exists.
178  if (!M.getModuleInlineAsm().empty()) {
179    OutStreamer.AddComment("Start of file scope inline assembly");
180    OutStreamer.AddBlankLine();
181    EmitInlineAsm(M.getModuleInlineAsm(), 0/*no loc cookie*/);
182    OutStreamer.AddComment("End of file scope inline assembly");
183    OutStreamer.AddBlankLine();
184  }
185
186  if (MAI->doesSupportDebugInformation())
187    DD = new DwarfDebug(this, &M);
188
189  if (MAI->doesSupportExceptionHandling())
190    DE = new DwarfException(this);
191
192  return false;
193}
194
195void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
196  switch ((GlobalValue::LinkageTypes)Linkage) {
197  case GlobalValue::CommonLinkage:
198  case GlobalValue::LinkOnceAnyLinkage:
199  case GlobalValue::LinkOnceODRLinkage:
200  case GlobalValue::WeakAnyLinkage:
201  case GlobalValue::WeakODRLinkage:
202  case GlobalValue::LinkerPrivateLinkage:
203    if (MAI->getWeakDefDirective() != 0) {
204      // .globl _foo
205      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
206      // .weak_definition _foo
207      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
208    } else if (MAI->getLinkOnceDirective() != 0) {
209      // .globl _foo
210      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
211      //NOTE: linkonce is handled by the section the symbol was assigned to.
212    } else {
213      // .weak _foo
214      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
215    }
216    break;
217  case GlobalValue::DLLExportLinkage:
218  case GlobalValue::AppendingLinkage:
219    // FIXME: appending linkage variables should go into a section of
220    // their name or something.  For now, just emit them as external.
221  case GlobalValue::ExternalLinkage:
222    // If external or appending, declare as a global symbol.
223    // .globl _foo
224    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
225    break;
226  case GlobalValue::PrivateLinkage:
227  case GlobalValue::InternalLinkage:
228    break;
229  default:
230    llvm_unreachable("Unknown linkage type!");
231  }
232}
233
234
235/// EmitGlobalVariable - Emit the specified global variable to the .s file.
236void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
237  if (!GV->hasInitializer())   // External globals require no code.
238    return;
239
240  // Check to see if this is a special global used by LLVM, if so, emit it.
241  if (EmitSpecialLLVMGlobal(GV))
242    return;
243
244  MCSymbol *GVSym = Mang->getSymbol(GV);
245  EmitVisibility(GVSym, GV->getVisibility());
246
247  if (MAI->hasDotTypeDotSizeDirective())
248    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
249
250  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
251
252  const TargetData *TD = TM.getTargetData();
253  uint64_t Size = TD->getTypeAllocSize(GV->getType()->getElementType());
254
255  // If the alignment is specified, we *must* obey it.  Overaligning a global
256  // with a specified alignment is a prompt way to break globals emitted to
257  // sections and expected to be contiguous (e.g. ObjC metadata).
258  unsigned AlignLog = getGVAlignmentLog2(GV, *TD);
259
260  // Handle common and BSS local symbols (.lcomm).
261  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
262    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
263
264    if (isVerbose()) {
265      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
266                     /*PrintType=*/false, GV->getParent());
267      OutStreamer.GetCommentOS() << '\n';
268    }
269
270    // Handle common symbols.
271    if (GVKind.isCommon()) {
272      // .comm _foo, 42, 4
273      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
274      return;
275    }
276
277    // Handle local BSS symbols.
278    if (MAI->hasMachoZeroFillDirective()) {
279      const MCSection *TheSection =
280        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
281      // .zerofill __DATA, __bss, _foo, 400, 5
282      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
283      return;
284    }
285
286    if (MAI->hasLCOMMDirective()) {
287      // .lcomm _foo, 42
288      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
289      return;
290    }
291
292    // .local _foo
293    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
294    // .comm _foo, 42, 4
295    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
296    return;
297  }
298
299  const MCSection *TheSection =
300    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
301
302  // Handle the zerofill directive on darwin, which is a special form of BSS
303  // emission.
304  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
305    if (Size == 0) Size = 1;  // zerofill of 0 bytes is undefined.
306
307    // .globl _foo
308    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
309    // .zerofill __DATA, __common, _foo, 400, 5
310    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
311    return;
312  }
313
314  // Handle thread local data for mach-o which requires us to output an
315  // additional structure of data and mangle the original symbol so that we
316  // can reference it later.
317  if (GVKind.isThreadLocal() && MAI->hasMachoTBSSDirective()) {
318    // Emit the .tbss symbol
319    MCSymbol *MangSym =
320      OutContext.GetOrCreateSymbol(GVSym->getName() + Twine("$tlv$init"));
321
322    if (GVKind.isThreadBSS())
323      OutStreamer.EmitTBSSSymbol(TheSection, MangSym, Size, 1 << AlignLog);
324    else if (GVKind.isThreadData()) {
325      OutStreamer.SwitchSection(TheSection);
326
327      EmitLinkage(GV->getLinkage(), MangSym);
328      EmitAlignment(AlignLog, GV);
329      OutStreamer.EmitLabel(MangSym);
330
331      EmitGlobalConstant(GV->getInitializer());
332    }
333
334    OutStreamer.AddBlankLine();
335
336    // Emit the variable struct for the runtime.
337    const MCSection *TLVSect
338      = getObjFileLowering().getTLSExtraDataSection();
339
340    OutStreamer.SwitchSection(TLVSect);
341    // Emit the linkage here.
342    EmitLinkage(GV->getLinkage(), GVSym);
343    OutStreamer.EmitLabel(GVSym);
344
345    // Three pointers in size:
346    //   - __tlv_bootstrap - used to make sure support exists
347    //   - spare pointer, used when mapped by the runtime
348    //   - pointer to mangled symbol above with initializer
349    unsigned PtrSize = TD->getPointerSizeInBits()/8;
350    OutStreamer.EmitSymbolValue(GetExternalSymbolSymbol("__tlv_bootstrap"),
351                          PtrSize, 0);
352    OutStreamer.EmitIntValue(0, PtrSize, 0);
353    OutStreamer.EmitSymbolValue(MangSym, PtrSize, 0);
354
355    OutStreamer.AddBlankLine();
356    return;
357  }
358
359  OutStreamer.SwitchSection(TheSection);
360
361  EmitLinkage(GV->getLinkage(), GVSym);
362  EmitAlignment(AlignLog, GV);
363
364  if (isVerbose()) {
365    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
366                   /*PrintType=*/false, GV->getParent());
367    OutStreamer.GetCommentOS() << '\n';
368  }
369  OutStreamer.EmitLabel(GVSym);
370
371  EmitGlobalConstant(GV->getInitializer());
372
373  if (MAI->hasDotTypeDotSizeDirective())
374    // .size foo, 42
375    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
376
377  OutStreamer.AddBlankLine();
378}
379
380/// EmitFunctionHeader - This method emits the header for the current
381/// function.
382void AsmPrinter::EmitFunctionHeader() {
383  // Print out constants referenced by the function
384  EmitConstantPool();
385
386  // Print the 'header' of function.
387  const Function *F = MF->getFunction();
388
389  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
390  EmitVisibility(CurrentFnSym, F->getVisibility());
391
392  EmitLinkage(F->getLinkage(), CurrentFnSym);
393  EmitAlignment(MF->getAlignment(), F);
394
395  if (MAI->hasDotTypeDotSizeDirective())
396    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
397
398  if (isVerbose()) {
399    WriteAsOperand(OutStreamer.GetCommentOS(), F,
400                   /*PrintType=*/false, F->getParent());
401    OutStreamer.GetCommentOS() << '\n';
402  }
403
404  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
405  // do their wild and crazy things as required.
406  EmitFunctionEntryLabel();
407
408  // If the function had address-taken blocks that got deleted, then we have
409  // references to the dangling symbols.  Emit them at the start of the function
410  // so that we don't get references to undefined symbols.
411  std::vector<MCSymbol*> DeadBlockSyms;
412  MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
413  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
414    OutStreamer.AddComment("Address taken block that was later removed");
415    OutStreamer.EmitLabel(DeadBlockSyms[i]);
416  }
417
418  // Add some workaround for linkonce linkage on Cygwin\MinGW.
419  if (MAI->getLinkOnceDirective() != 0 &&
420      (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
421    // FIXME: What is this?
422    MCSymbol *FakeStub =
423      OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
424                                   CurrentFnSym->getName());
425    OutStreamer.EmitLabel(FakeStub);
426  }
427
428  // Emit pre-function debug and/or EH information.
429  if (DE) {
430    if (TimePassesIsEnabled) {
431      NamedRegionTimer T(EHTimerName, DWARFGroupName);
432      DE->BeginFunction(MF);
433    } else {
434      DE->BeginFunction(MF);
435    }
436  }
437  if (DD) {
438    if (TimePassesIsEnabled) {
439      NamedRegionTimer T(DbgTimerName, DWARFGroupName);
440      DD->beginFunction(MF);
441    } else {
442      DD->beginFunction(MF);
443    }
444  }
445}
446
447/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
448/// function.  This can be overridden by targets as required to do custom stuff.
449void AsmPrinter::EmitFunctionEntryLabel() {
450  // The function label could have already been emitted if two symbols end up
451  // conflicting due to asm renaming.  Detect this and emit an error.
452  if (CurrentFnSym->isUndefined())
453    return OutStreamer.EmitLabel(CurrentFnSym);
454
455  report_fatal_error("'" + Twine(CurrentFnSym->getName()) +
456                     "' label emitted multiple times to assembly file");
457}
458
459
460/// EmitComments - Pretty-print comments for instructions.
461static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
462  const MachineFunction *MF = MI.getParent()->getParent();
463  const TargetMachine &TM = MF->getTarget();
464
465  DebugLoc DL = MI.getDebugLoc();
466  if (!DL.isUnknown()) {          // Print source line info.
467    DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
468    // Omit the directory, because it's likely to be long and uninteresting.
469    if (Scope.Verify())
470      CommentOS << Scope.getFilename();
471    else
472      CommentOS << "<unknown>";
473    CommentOS << ':' << DL.getLine();
474    if (DL.getCol() != 0)
475      CommentOS << ':' << DL.getCol();
476    CommentOS << '\n';
477  }
478
479  // Check for spills and reloads
480  int FI;
481
482  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
483
484  // We assume a single instruction only has a spill or reload, not
485  // both.
486  const MachineMemOperand *MMO;
487  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
488    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
489      MMO = *MI.memoperands_begin();
490      CommentOS << MMO->getSize() << "-byte Reload\n";
491    }
492  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
493    if (FrameInfo->isSpillSlotObjectIndex(FI))
494      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
495  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
496    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
497      MMO = *MI.memoperands_begin();
498      CommentOS << MMO->getSize() << "-byte Spill\n";
499    }
500  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
501    if (FrameInfo->isSpillSlotObjectIndex(FI))
502      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
503  }
504
505  // Check for spill-induced copies
506  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
507  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
508                                     SrcSubIdx, DstSubIdx)) {
509    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
510      CommentOS << " Reload Reuse\n";
511  }
512}
513
514/// EmitImplicitDef - This method emits the specified machine instruction
515/// that is an implicit def.
516static void EmitImplicitDef(const MachineInstr *MI, AsmPrinter &AP) {
517  unsigned RegNo = MI->getOperand(0).getReg();
518  AP.OutStreamer.AddComment(Twine("implicit-def: ") +
519                            AP.TM.getRegisterInfo()->getName(RegNo));
520  AP.OutStreamer.AddBlankLine();
521}
522
523static void EmitKill(const MachineInstr *MI, AsmPrinter &AP) {
524  std::string Str = "kill:";
525  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
526    const MachineOperand &Op = MI->getOperand(i);
527    assert(Op.isReg() && "KILL instruction must have only register operands");
528    Str += ' ';
529    Str += AP.TM.getRegisterInfo()->getName(Op.getReg());
530    Str += (Op.isDef() ? "<def>" : "<kill>");
531  }
532  AP.OutStreamer.AddComment(Str);
533  AP.OutStreamer.AddBlankLine();
534}
535
536/// EmitDebugValueComment - This method handles the target-independent form
537/// of DBG_VALUE, returning true if it was able to do so.  A false return
538/// means the target will need to handle MI in EmitInstruction.
539static bool EmitDebugValueComment(const MachineInstr *MI, AsmPrinter &AP) {
540  // This code handles only the 3-operand target-independent form.
541  if (MI->getNumOperands() != 3)
542    return false;
543
544  SmallString<128> Str;
545  raw_svector_ostream OS(Str);
546  OS << '\t' << AP.MAI->getCommentString() << "DEBUG_VALUE: ";
547
548  // cast away const; DIetc do not take const operands for some reason.
549  DIVariable V(const_cast<MDNode*>(MI->getOperand(2).getMetadata()));
550  if (V.getContext().isSubprogram())
551    OS << DISubprogram(V.getContext()).getDisplayName() << ":";
552  OS << V.getName() << " <- ";
553
554  // Register or immediate value. Register 0 means undef.
555  if (MI->getOperand(0).isFPImm()) {
556    APFloat APF = APFloat(MI->getOperand(0).getFPImm()->getValueAPF());
557    if (MI->getOperand(0).getFPImm()->getType()->isFloatTy()) {
558      OS << (double)APF.convertToFloat();
559    } else if (MI->getOperand(0).getFPImm()->getType()->isDoubleTy()) {
560      OS << APF.convertToDouble();
561    } else {
562      // There is no good way to print long double.  Convert a copy to
563      // double.  Ah well, it's only a comment.
564      bool ignored;
565      APF.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
566                  &ignored);
567      OS << "(long double) " << APF.convertToDouble();
568    }
569  } else if (MI->getOperand(0).isImm()) {
570    OS << MI->getOperand(0).getImm();
571  } else {
572    assert(MI->getOperand(0).isReg() && "Unknown operand type");
573    if (MI->getOperand(0).getReg() == 0) {
574      // Suppress offset, it is not meaningful here.
575      OS << "undef";
576      // NOTE: Want this comment at start of line, don't emit with AddComment.
577      AP.OutStreamer.EmitRawText(OS.str());
578      return true;
579    }
580    OS << AP.TM.getRegisterInfo()->getName(MI->getOperand(0).getReg());
581  }
582
583  OS << '+' << MI->getOperand(1).getImm();
584  // NOTE: Want this comment at start of line, don't emit with AddComment.
585  AP.OutStreamer.EmitRawText(OS.str());
586  return true;
587}
588
589/// EmitFunctionBody - This method emits the body and trailer for a
590/// function.
591void AsmPrinter::EmitFunctionBody() {
592  // Emit target-specific gunk before the function body.
593  EmitFunctionBodyStart();
594
595  bool ShouldPrintDebugScopes = DD && MMI->hasDebugInfo();
596
597  // Print out code for the function.
598  bool HasAnyRealCode = false;
599  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
600       I != E; ++I) {
601    // Print a label for the basic block.
602    EmitBasicBlockStart(I);
603    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
604         II != IE; ++II) {
605      // Print the assembly for the instruction.
606      if (!II->isLabel() && !II->isImplicitDef() && !II->isKill() &&
607          !II->isDebugValue()) {
608        HasAnyRealCode = true;
609        ++EmittedInsts;
610      }
611
612      if (ShouldPrintDebugScopes) {
613	if (TimePassesIsEnabled) {
614	  NamedRegionTimer T(DbgTimerName, DWARFGroupName);
615	  DD->beginScope(II);
616	} else {
617	  DD->beginScope(II);
618	}
619      }
620
621      if (isVerbose())
622        EmitComments(*II, OutStreamer.GetCommentOS());
623
624      switch (II->getOpcode()) {
625      case TargetOpcode::DBG_LABEL:
626      case TargetOpcode::EH_LABEL:
627      case TargetOpcode::GC_LABEL:
628        OutStreamer.EmitLabel(II->getOperand(0).getMCSymbol());
629        break;
630      case TargetOpcode::INLINEASM:
631        EmitInlineAsm(II);
632        break;
633      case TargetOpcode::DBG_VALUE:
634        if (isVerbose()) {
635          if (!EmitDebugValueComment(II, *this))
636            EmitInstruction(II);
637        }
638        break;
639      case TargetOpcode::IMPLICIT_DEF:
640        if (isVerbose()) EmitImplicitDef(II, *this);
641        break;
642      case TargetOpcode::KILL:
643        if (isVerbose()) EmitKill(II, *this);
644        break;
645      default:
646        EmitInstruction(II);
647        break;
648      }
649
650      if (ShouldPrintDebugScopes) {
651	if (TimePassesIsEnabled) {
652	  NamedRegionTimer T(DbgTimerName, DWARFGroupName);
653	  DD->endScope(II);
654	} else {
655	  DD->endScope(II);
656	}
657      }
658    }
659  }
660
661  // If the function is empty and the object file uses .subsections_via_symbols,
662  // then we need to emit *something* to the function body to prevent the
663  // labels from collapsing together.  Just emit a noop.
664  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode) {
665    MCInst Noop;
666    TM.getInstrInfo()->getNoopForMachoTarget(Noop);
667    if (Noop.getOpcode()) {
668      OutStreamer.AddComment("avoids zero-length function");
669      OutStreamer.EmitInstruction(Noop);
670    } else  // Target not mc-ized yet.
671      OutStreamer.EmitRawText(StringRef("\tnop\n"));
672  }
673
674  // Emit target-specific gunk after the function body.
675  EmitFunctionBodyEnd();
676
677  // If the target wants a .size directive for the size of the function, emit
678  // it.
679  if (MAI->hasDotTypeDotSizeDirective()) {
680    // Create a symbol for the end of function, so we can get the size as
681    // difference between the function label and the temp label.
682    MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
683    OutStreamer.EmitLabel(FnEndLabel);
684
685    const MCExpr *SizeExp =
686      MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
687                              MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
688                              OutContext);
689    OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
690  }
691
692  // Emit post-function debug information.
693  if (DD) {
694    if (TimePassesIsEnabled) {
695      NamedRegionTimer T(DbgTimerName, DWARFGroupName);
696      DD->endFunction(MF);
697    } else {
698      DD->endFunction(MF);
699    }
700  }
701  if (DE) {
702    if (TimePassesIsEnabled) {
703      NamedRegionTimer T(EHTimerName, DWARFGroupName);
704      DE->EndFunction();
705    } else {
706      DE->EndFunction();
707    }
708  }
709  MMI->EndFunction();
710
711  // Print out jump tables referenced by the function.
712  EmitJumpTableInfo();
713
714  OutStreamer.AddBlankLine();
715}
716
717/// getDebugValueLocation - Get location information encoded by DBG_VALUE
718/// operands.
719MachineLocation AsmPrinter::getDebugValueLocation(const MachineInstr *MI) const {
720  // Target specific DBG_VALUE instructions are handled by each target.
721  return MachineLocation();
722}
723
724bool AsmPrinter::doFinalization(Module &M) {
725  // Emit global variables.
726  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
727       I != E; ++I)
728    EmitGlobalVariable(I);
729
730  // Finalize debug and EH information.
731  if (DE) {
732    if (TimePassesIsEnabled) {
733      NamedRegionTimer T(EHTimerName, DWARFGroupName);
734      DE->EndModule();
735    } else {
736      DE->EndModule();
737    }
738    delete DE; DE = 0;
739  }
740  if (DD) {
741    if (TimePassesIsEnabled) {
742      NamedRegionTimer T(DbgTimerName, DWARFGroupName);
743      DD->endModule();
744    } else {
745      DD->endModule();
746    }
747    delete DD; DD = 0;
748  }
749
750  // If the target wants to know about weak references, print them all.
751  if (MAI->getWeakRefDirective()) {
752    // FIXME: This is not lazy, it would be nice to only print weak references
753    // to stuff that is actually used.  Note that doing so would require targets
754    // to notice uses in operands (due to constant exprs etc).  This should
755    // happen with the MC stuff eventually.
756
757    // Print out module-level global variables here.
758    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
759         I != E; ++I) {
760      if (!I->hasExternalWeakLinkage()) continue;
761      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
762    }
763
764    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
765      if (!I->hasExternalWeakLinkage()) continue;
766      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
767    }
768  }
769
770  if (MAI->hasSetDirective()) {
771    OutStreamer.AddBlankLine();
772    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
773         I != E; ++I) {
774      MCSymbol *Name = Mang->getSymbol(I);
775
776      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
777      MCSymbol *Target = Mang->getSymbol(GV);
778
779      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
780        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
781      else if (I->hasWeakLinkage())
782        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
783      else
784        assert(I->hasLocalLinkage() && "Invalid alias linkage");
785
786      EmitVisibility(Name, I->getVisibility());
787
788      // Emit the directives as assignments aka .set:
789      OutStreamer.EmitAssignment(Name,
790                                 MCSymbolRefExpr::Create(Target, OutContext));
791    }
792  }
793
794  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
795  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
796  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
797    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
798      MP->finishAssembly(*this);
799
800  // If we don't have any trampolines, then we don't require stack memory
801  // to be executable. Some targets have a directive to declare this.
802  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
803  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
804    if (const MCSection *S = MAI->getNonexecutableStackSection(OutContext))
805      OutStreamer.SwitchSection(S);
806
807  // Allow the target to emit any magic that it wants at the end of the file,
808  // after everything else has gone out.
809  EmitEndOfAsmFile(M);
810
811  delete Mang; Mang = 0;
812  MMI = 0;
813
814  OutStreamer.Finish();
815  return false;
816}
817
818void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
819  this->MF = &MF;
820  // Get the function symbol.
821  CurrentFnSym = Mang->getSymbol(MF.getFunction());
822
823  if (isVerbose())
824    LI = &getAnalysis<MachineLoopInfo>();
825}
826
827namespace {
828  // SectionCPs - Keep track the alignment, constpool entries per Section.
829  struct SectionCPs {
830    const MCSection *S;
831    unsigned Alignment;
832    SmallVector<unsigned, 4> CPEs;
833    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
834  };
835}
836
837/// EmitConstantPool - Print to the current output stream assembly
838/// representations of the constants in the constant pool MCP. This is
839/// used to print out constants which have been "spilled to memory" by
840/// the code generator.
841///
842void AsmPrinter::EmitConstantPool() {
843  const MachineConstantPool *MCP = MF->getConstantPool();
844  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
845  if (CP.empty()) return;
846
847  // Calculate sections for constant pool entries. We collect entries to go into
848  // the same section together to reduce amount of section switch statements.
849  SmallVector<SectionCPs, 4> CPSections;
850  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
851    const MachineConstantPoolEntry &CPE = CP[i];
852    unsigned Align = CPE.getAlignment();
853
854    SectionKind Kind;
855    switch (CPE.getRelocationInfo()) {
856    default: llvm_unreachable("Unknown section kind");
857    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
858    case 1:
859      Kind = SectionKind::getReadOnlyWithRelLocal();
860      break;
861    case 0:
862    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
863    case 4:  Kind = SectionKind::getMergeableConst4(); break;
864    case 8:  Kind = SectionKind::getMergeableConst8(); break;
865    case 16: Kind = SectionKind::getMergeableConst16();break;
866    default: Kind = SectionKind::getMergeableConst(); break;
867    }
868    }
869
870    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
871
872    // The number of sections are small, just do a linear search from the
873    // last section to the first.
874    bool Found = false;
875    unsigned SecIdx = CPSections.size();
876    while (SecIdx != 0) {
877      if (CPSections[--SecIdx].S == S) {
878        Found = true;
879        break;
880      }
881    }
882    if (!Found) {
883      SecIdx = CPSections.size();
884      CPSections.push_back(SectionCPs(S, Align));
885    }
886
887    if (Align > CPSections[SecIdx].Alignment)
888      CPSections[SecIdx].Alignment = Align;
889    CPSections[SecIdx].CPEs.push_back(i);
890  }
891
892  // Now print stuff into the calculated sections.
893  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
894    OutStreamer.SwitchSection(CPSections[i].S);
895    EmitAlignment(Log2_32(CPSections[i].Alignment));
896
897    unsigned Offset = 0;
898    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
899      unsigned CPI = CPSections[i].CPEs[j];
900      MachineConstantPoolEntry CPE = CP[CPI];
901
902      // Emit inter-object padding for alignment.
903      unsigned AlignMask = CPE.getAlignment() - 1;
904      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
905      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
906
907      const Type *Ty = CPE.getType();
908      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
909
910      // Emit the label with a comment on it.
911      if (isVerbose()) {
912        OutStreamer.GetCommentOS() << "constant pool ";
913        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
914                          MF->getFunction()->getParent());
915        OutStreamer.GetCommentOS() << '\n';
916      }
917      OutStreamer.EmitLabel(GetCPISymbol(CPI));
918
919      if (CPE.isMachineConstantPoolEntry())
920        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
921      else
922        EmitGlobalConstant(CPE.Val.ConstVal);
923    }
924  }
925}
926
927/// EmitJumpTableInfo - Print assembly representations of the jump tables used
928/// by the current function to the current output stream.
929///
930void AsmPrinter::EmitJumpTableInfo() {
931  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
932  if (MJTI == 0) return;
933  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
934  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
935  if (JT.empty()) return;
936
937  // Pick the directive to use to print the jump table entries, and switch to
938  // the appropriate section.
939  const Function *F = MF->getFunction();
940  bool JTInDiffSection = false;
941  if (// In PIC mode, we need to emit the jump table to the same section as the
942      // function body itself, otherwise the label differences won't make sense.
943      // FIXME: Need a better predicate for this: what about custom entries?
944      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
945      // We should also do if the section name is NULL or function is declared
946      // in discardable section
947      // FIXME: this isn't the right predicate, should be based on the MCSection
948      // for the function.
949      F->isWeakForLinker()) {
950    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
951  } else {
952    // Otherwise, drop it in the readonly section.
953    const MCSection *ReadOnlySection =
954      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
955    OutStreamer.SwitchSection(ReadOnlySection);
956    JTInDiffSection = true;
957  }
958
959  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
960
961  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
962    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
963
964    // If this jump table was deleted, ignore it.
965    if (JTBBs.empty()) continue;
966
967    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
968    // .set directive for each unique entry.  This reduces the number of
969    // relocations the assembler will generate for the jump table.
970    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
971        MAI->hasSetDirective()) {
972      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
973      const TargetLowering *TLI = TM.getTargetLowering();
974      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
975      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
976        const MachineBasicBlock *MBB = JTBBs[ii];
977        if (!EmittedSets.insert(MBB)) continue;
978
979        // .set LJTSet, LBB32-base
980        const MCExpr *LHS =
981          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
982        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
983                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
984      }
985    }
986
987    // On some targets (e.g. Darwin) we want to emit two consequtive labels
988    // before each jump table.  The first label is never referenced, but tells
989    // the assembler and linker the extents of the jump table object.  The
990    // second label is actually referenced by the code.
991    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
992      // FIXME: This doesn't have to have any specific name, just any randomly
993      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
994      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
995
996    OutStreamer.EmitLabel(GetJTISymbol(JTI));
997
998    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
999      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
1000  }
1001}
1002
1003/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
1004/// current stream.
1005void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
1006                                    const MachineBasicBlock *MBB,
1007                                    unsigned UID) const {
1008  const MCExpr *Value = 0;
1009  switch (MJTI->getEntryKind()) {
1010  case MachineJumpTableInfo::EK_Inline:
1011    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
1012  case MachineJumpTableInfo::EK_Custom32:
1013    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
1014                                                              OutContext);
1015    break;
1016  case MachineJumpTableInfo::EK_BlockAddress:
1017    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1018    //     .word LBB123
1019    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1020    break;
1021  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
1022    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
1023    // with a relocation as gp-relative, e.g.:
1024    //     .gprel32 LBB123
1025    MCSymbol *MBBSym = MBB->getSymbol();
1026    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
1027    return;
1028  }
1029
1030  case MachineJumpTableInfo::EK_LabelDifference32: {
1031    // EK_LabelDifference32 - Each entry is the address of the block minus
1032    // the address of the jump table.  This is used for PIC jump tables where
1033    // gprel32 is not supported.  e.g.:
1034    //      .word LBB123 - LJTI1_2
1035    // If the .set directive is supported, this is emitted as:
1036    //      .set L4_5_set_123, LBB123 - LJTI1_2
1037    //      .word L4_5_set_123
1038
1039    // If we have emitted set directives for the jump table entries, print
1040    // them rather than the entries themselves.  If we're emitting PIC, then
1041    // emit the table entries as differences between two text section labels.
1042    if (MAI->hasSetDirective()) {
1043      // If we used .set, reference the .set's symbol.
1044      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
1045                                      OutContext);
1046      break;
1047    }
1048    // Otherwise, use the difference as the jump table entry.
1049    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
1050    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
1051    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
1052    break;
1053  }
1054  }
1055
1056  assert(Value && "Unknown entry kind!");
1057
1058  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
1059  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
1060}
1061
1062
1063/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
1064/// special global used by LLVM.  If so, emit it and return true, otherwise
1065/// do nothing and return false.
1066bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
1067  if (GV->getName() == "llvm.used") {
1068    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
1069      EmitLLVMUsedList(GV->getInitializer());
1070    return true;
1071  }
1072
1073  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
1074  if (GV->getSection() == "llvm.metadata" ||
1075      GV->hasAvailableExternallyLinkage())
1076    return true;
1077
1078  if (!GV->hasAppendingLinkage()) return false;
1079
1080  assert(GV->hasInitializer() && "Not a special LLVM global!");
1081
1082  const TargetData *TD = TM.getTargetData();
1083  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
1084  if (GV->getName() == "llvm.global_ctors") {
1085    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
1086    EmitAlignment(Align);
1087    EmitXXStructorList(GV->getInitializer());
1088
1089    if (TM.getRelocationModel() == Reloc::Static &&
1090        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1091      StringRef Sym(".constructors_used");
1092      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1093                                      MCSA_Reference);
1094    }
1095    return true;
1096  }
1097
1098  if (GV->getName() == "llvm.global_dtors") {
1099    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
1100    EmitAlignment(Align);
1101    EmitXXStructorList(GV->getInitializer());
1102
1103    if (TM.getRelocationModel() == Reloc::Static &&
1104        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
1105      StringRef Sym(".destructors_used");
1106      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
1107                                      MCSA_Reference);
1108    }
1109    return true;
1110  }
1111
1112  return false;
1113}
1114
1115/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
1116/// global in the specified llvm.used list for which emitUsedDirectiveFor
1117/// is true, as being used with this directive.
1118void AsmPrinter::EmitLLVMUsedList(Constant *List) {
1119  // Should be an array of 'i8*'.
1120  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
1121  if (InitList == 0) return;
1122
1123  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
1124    const GlobalValue *GV =
1125      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
1126    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
1127      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
1128  }
1129}
1130
1131/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
1132/// function pointers, ignoring the init priority.
1133void AsmPrinter::EmitXXStructorList(Constant *List) {
1134  // Should be an array of '{ int, void ()* }' structs.  The first value is the
1135  // init priority, which we ignore.
1136  if (!isa<ConstantArray>(List)) return;
1137  ConstantArray *InitList = cast<ConstantArray>(List);
1138  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
1139    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
1140      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
1141
1142      if (CS->getOperand(1)->isNullValue())
1143        return;  // Found a null terminator, exit printing.
1144      // Emit the function pointer.
1145      EmitGlobalConstant(CS->getOperand(1));
1146    }
1147}
1148
1149//===--------------------------------------------------------------------===//
1150// Emission and print routines
1151//
1152
1153/// EmitInt8 - Emit a byte directive and value.
1154///
1155void AsmPrinter::EmitInt8(int Value) const {
1156  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
1157}
1158
1159/// EmitInt16 - Emit a short directive and value.
1160///
1161void AsmPrinter::EmitInt16(int Value) const {
1162  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
1163}
1164
1165/// EmitInt32 - Emit a long directive and value.
1166///
1167void AsmPrinter::EmitInt32(int Value) const {
1168  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
1169}
1170
1171/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
1172/// in bytes of the directive is specified by Size and Hi/Lo specify the
1173/// labels.  This implicitly uses .set if it is available.
1174void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
1175                                     unsigned Size) const {
1176  // Get the Hi-Lo expression.
1177  const MCExpr *Diff =
1178    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
1179                            MCSymbolRefExpr::Create(Lo, OutContext),
1180                            OutContext);
1181
1182  if (!MAI->hasSetDirective()) {
1183    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
1184    return;
1185  }
1186
1187  // Otherwise, emit with .set (aka assignment).
1188  MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1189  OutStreamer.EmitAssignment(SetLabel, Diff);
1190  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
1191}
1192
1193/// EmitLabelOffsetDifference - Emit something like ".long Hi+Offset-Lo"
1194/// where the size in bytes of the directive is specified by Size and Hi/Lo
1195/// specify the labels.  This implicitly uses .set if it is available.
1196void AsmPrinter::EmitLabelOffsetDifference(const MCSymbol *Hi, uint64_t Offset,
1197                                           const MCSymbol *Lo, unsigned Size)
1198  const {
1199
1200  // Emit Hi+Offset - Lo
1201  // Get the Hi+Offset expression.
1202  const MCExpr *Plus =
1203    MCBinaryExpr::CreateAdd(MCSymbolRefExpr::Create(Hi, OutContext),
1204                            MCConstantExpr::Create(Offset, OutContext),
1205                            OutContext);
1206
1207  // Get the Hi+Offset-Lo expression.
1208  const MCExpr *Diff =
1209    MCBinaryExpr::CreateSub(Plus,
1210                            MCSymbolRefExpr::Create(Lo, OutContext),
1211                            OutContext);
1212
1213  if (!MAI->hasSetDirective())
1214    OutStreamer.EmitValue(Diff, 4, 0/*AddrSpace*/);
1215  else {
1216    // Otherwise, emit with .set (aka assignment).
1217    MCSymbol *SetLabel = GetTempSymbol("set", SetCounter++);
1218    OutStreamer.EmitAssignment(SetLabel, Diff);
1219    OutStreamer.EmitSymbolValue(SetLabel, 4, 0/*AddrSpace*/);
1220  }
1221}
1222
1223
1224//===----------------------------------------------------------------------===//
1225
1226// EmitAlignment - Emit an alignment directive to the specified power of
1227// two boundary.  For example, if you pass in 3 here, you will get an 8
1228// byte alignment.  If a global value is specified, and if that global has
1229// an explicit alignment requested, it will override the alignment request
1230// if required for correctness.
1231//
1232void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV) const {
1233  if (GV) NumBits = getGVAlignmentLog2(GV, *TM.getTargetData(), NumBits);
1234
1235  if (NumBits == 0) return;   // 1-byte aligned: no need to emit alignment.
1236
1237  if (getCurrentSection()->getKind().isText())
1238    OutStreamer.EmitCodeAlignment(1 << NumBits);
1239  else
1240    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
1241}
1242
1243//===----------------------------------------------------------------------===//
1244// Constant emission.
1245//===----------------------------------------------------------------------===//
1246
1247/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
1248///
1249static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
1250  MCContext &Ctx = AP.OutContext;
1251
1252  if (CV->isNullValue() || isa<UndefValue>(CV))
1253    return MCConstantExpr::Create(0, Ctx);
1254
1255  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
1256    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
1257
1258  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1259    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1260  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1261    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1262
1263  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1264  if (CE == 0) {
1265    llvm_unreachable("Unknown constant value to lower!");
1266    return MCConstantExpr::Create(0, Ctx);
1267  }
1268
1269  switch (CE->getOpcode()) {
1270  default:
1271    // If the code isn't optimized, there may be outstanding folding
1272    // opportunities. Attempt to fold the expression using TargetData as a
1273    // last resort before giving up.
1274    if (Constant *C =
1275          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1276      if (C != CE)
1277        return LowerConstant(C, AP);
1278#ifndef NDEBUG
1279    CE->dump();
1280#endif
1281    llvm_unreachable("FIXME: Don't support this constant expr");
1282  case Instruction::GetElementPtr: {
1283    const TargetData &TD = *AP.TM.getTargetData();
1284    // Generate a symbolic expression for the byte address
1285    const Constant *PtrVal = CE->getOperand(0);
1286    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1287    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1288                                         IdxVec.size());
1289
1290    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1291    if (Offset == 0)
1292      return Base;
1293
1294    // Truncate/sext the offset to the pointer size.
1295    if (TD.getPointerSizeInBits() != 64) {
1296      int SExtAmount = 64-TD.getPointerSizeInBits();
1297      Offset = (Offset << SExtAmount) >> SExtAmount;
1298    }
1299
1300    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1301                                   Ctx);
1302  }
1303
1304  case Instruction::Trunc:
1305    // We emit the value and depend on the assembler to truncate the generated
1306    // expression properly.  This is important for differences between
1307    // blockaddress labels.  Since the two labels are in the same function, it
1308    // is reasonable to treat their delta as a 32-bit value.
1309    // FALL THROUGH.
1310  case Instruction::BitCast:
1311    return LowerConstant(CE->getOperand(0), AP);
1312
1313  case Instruction::IntToPtr: {
1314    const TargetData &TD = *AP.TM.getTargetData();
1315    // Handle casts to pointers by changing them into casts to the appropriate
1316    // integer type.  This promotes constant folding and simplifies this code.
1317    Constant *Op = CE->getOperand(0);
1318    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1319                                      false/*ZExt*/);
1320    return LowerConstant(Op, AP);
1321  }
1322
1323  case Instruction::PtrToInt: {
1324    const TargetData &TD = *AP.TM.getTargetData();
1325    // Support only foldable casts to/from pointers that can be eliminated by
1326    // changing the pointer to the appropriately sized integer type.
1327    Constant *Op = CE->getOperand(0);
1328    const Type *Ty = CE->getType();
1329
1330    const MCExpr *OpExpr = LowerConstant(Op, AP);
1331
1332    // We can emit the pointer value into this slot if the slot is an
1333    // integer slot equal to the size of the pointer.
1334    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1335      return OpExpr;
1336
1337    // Otherwise the pointer is smaller than the resultant integer, mask off
1338    // the high bits so we are sure to get a proper truncation if the input is
1339    // a constant expr.
1340    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1341    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1342    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1343  }
1344
1345  // The MC library also has a right-shift operator, but it isn't consistently
1346  // signed or unsigned between different targets.
1347  case Instruction::Add:
1348  case Instruction::Sub:
1349  case Instruction::Mul:
1350  case Instruction::SDiv:
1351  case Instruction::SRem:
1352  case Instruction::Shl:
1353  case Instruction::And:
1354  case Instruction::Or:
1355  case Instruction::Xor: {
1356    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1357    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1358    switch (CE->getOpcode()) {
1359    default: llvm_unreachable("Unknown binary operator constant cast expr");
1360    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1361    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1362    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1363    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1364    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1365    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1366    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1367    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1368    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1369    }
1370  }
1371  }
1372}
1373
1374static void EmitGlobalConstantImpl(const Constant *C, unsigned AddrSpace,
1375                                   AsmPrinter &AP);
1376
1377static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1378                                    AsmPrinter &AP) {
1379  if (AddrSpace != 0 || !CA->isString()) {
1380    // Not a string.  Print the values in successive locations
1381    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1382      EmitGlobalConstantImpl(CA->getOperand(i), AddrSpace, AP);
1383    return;
1384  }
1385
1386  // Otherwise, it can be emitted as .ascii.
1387  SmallVector<char, 128> TmpVec;
1388  TmpVec.reserve(CA->getNumOperands());
1389  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1390    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1391
1392  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1393}
1394
1395static void EmitGlobalConstantVector(const ConstantVector *CV,
1396                                     unsigned AddrSpace, AsmPrinter &AP) {
1397  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1398    EmitGlobalConstantImpl(CV->getOperand(i), AddrSpace, AP);
1399}
1400
1401static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1402                                     unsigned AddrSpace, AsmPrinter &AP) {
1403  // Print the fields in successive locations. Pad to align if needed!
1404  const TargetData *TD = AP.TM.getTargetData();
1405  unsigned Size = TD->getTypeAllocSize(CS->getType());
1406  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1407  uint64_t SizeSoFar = 0;
1408  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1409    const Constant *Field = CS->getOperand(i);
1410
1411    // Check if padding is needed and insert one or more 0s.
1412    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1413    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1414                        - Layout->getElementOffset(i)) - FieldSize;
1415    SizeSoFar += FieldSize + PadSize;
1416
1417    // Now print the actual field value.
1418    EmitGlobalConstantImpl(Field, AddrSpace, AP);
1419
1420    // Insert padding - this may include padding to increase the size of the
1421    // current field up to the ABI size (if the struct is not packed) as well
1422    // as padding to ensure that the next field starts at the right offset.
1423    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1424  }
1425  assert(SizeSoFar == Layout->getSizeInBytes() &&
1426         "Layout of constant struct may be incorrect!");
1427}
1428
1429static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1430                                    unsigned AddrSpace, AsmPrinter &AP) {
1431  const TargetData *TD = AP.TM.getTargetData();
1432  unsigned Size = TD->getTypeAllocSize(CU->getType());
1433
1434  const Constant *Contents = CU->getOperand(0);
1435  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1436
1437  // Print the actually filled part
1438  EmitGlobalConstantImpl(Contents, AddrSpace, AP);
1439
1440  // And pad with enough zeroes
1441  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1442}
1443
1444static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1445                                 AsmPrinter &AP) {
1446  // FP Constants are printed as integer constants to avoid losing
1447  // precision.
1448  if (CFP->getType()->isDoubleTy()) {
1449    if (AP.isVerbose()) {
1450      double Val = CFP->getValueAPF().convertToDouble();
1451      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1452    }
1453
1454    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1455    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1456    return;
1457  }
1458
1459  if (CFP->getType()->isFloatTy()) {
1460    if (AP.isVerbose()) {
1461      float Val = CFP->getValueAPF().convertToFloat();
1462      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1463    }
1464    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1465    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1466    return;
1467  }
1468
1469  if (CFP->getType()->isX86_FP80Ty()) {
1470    // all long double variants are printed as hex
1471    // API needed to prevent premature destruction
1472    APInt API = CFP->getValueAPF().bitcastToAPInt();
1473    const uint64_t *p = API.getRawData();
1474    if (AP.isVerbose()) {
1475      // Convert to double so we can print the approximate val as a comment.
1476      APFloat DoubleVal = CFP->getValueAPF();
1477      bool ignored;
1478      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1479                        &ignored);
1480      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1481        << DoubleVal.convertToDouble() << '\n';
1482    }
1483
1484    if (AP.TM.getTargetData()->isBigEndian()) {
1485      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1486      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1487    } else {
1488      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1489      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1490    }
1491
1492    // Emit the tail padding for the long double.
1493    const TargetData &TD = *AP.TM.getTargetData();
1494    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1495                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1496    return;
1497  }
1498
1499  assert(CFP->getType()->isPPC_FP128Ty() &&
1500         "Floating point constant type not handled");
1501  // All long double variants are printed as hex
1502  // API needed to prevent premature destruction.
1503  APInt API = CFP->getValueAPF().bitcastToAPInt();
1504  const uint64_t *p = API.getRawData();
1505  if (AP.TM.getTargetData()->isBigEndian()) {
1506    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1507    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1508  } else {
1509    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1510    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1511  }
1512}
1513
1514static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1515                                       unsigned AddrSpace, AsmPrinter &AP) {
1516  const TargetData *TD = AP.TM.getTargetData();
1517  unsigned BitWidth = CI->getBitWidth();
1518  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1519
1520  // We don't expect assemblers to support integer data directives
1521  // for more than 64 bits, so we emit the data in at most 64-bit
1522  // quantities at a time.
1523  const uint64_t *RawData = CI->getValue().getRawData();
1524  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1525    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1526    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1527  }
1528}
1529
1530static void EmitGlobalConstantImpl(const Constant *CV, unsigned AddrSpace,
1531                                   AsmPrinter &AP) {
1532  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1533    uint64_t Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1534    return AP.OutStreamer.EmitZeros(Size, AddrSpace);
1535  }
1536
1537  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1538    unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1539    switch (Size) {
1540    case 1:
1541    case 2:
1542    case 4:
1543    case 8:
1544      if (AP.isVerbose())
1545        AP.OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1546        AP.OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1547      return;
1548    default:
1549      EmitGlobalConstantLargeInt(CI, AddrSpace, AP);
1550      return;
1551    }
1552  }
1553
1554  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1555    return EmitGlobalConstantArray(CVA, AddrSpace, AP);
1556
1557  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1558    return EmitGlobalConstantStruct(CVS, AddrSpace, AP);
1559
1560  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1561    return EmitGlobalConstantFP(CFP, AddrSpace, AP);
1562
1563  if (isa<ConstantPointerNull>(CV)) {
1564    unsigned Size = AP.TM.getTargetData()->getTypeAllocSize(CV->getType());
1565    AP.OutStreamer.EmitIntValue(0, Size, AddrSpace);
1566    return;
1567  }
1568
1569  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1570    return EmitGlobalConstantUnion(CVU, AddrSpace, AP);
1571
1572  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1573    return EmitGlobalConstantVector(V, AddrSpace, AP);
1574
1575  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1576  // thread the streamer with EmitValue.
1577  AP.OutStreamer.EmitValue(LowerConstant(CV, AP),
1578                         AP.TM.getTargetData()->getTypeAllocSize(CV->getType()),
1579                           AddrSpace);
1580}
1581
1582/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1583void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1584  uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1585  if (Size)
1586    EmitGlobalConstantImpl(CV, AddrSpace, *this);
1587  else if (MAI->hasSubsectionsViaSymbols()) {
1588    // If the global has zero size, emit a single byte so that two labels don't
1589    // look like they are at the same location.
1590    OutStreamer.EmitIntValue(0, 1, AddrSpace);
1591  }
1592}
1593
1594void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1595  // Target doesn't support this yet!
1596  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1597}
1598
1599void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1600  if (Offset > 0)
1601    OS << '+' << Offset;
1602  else if (Offset < 0)
1603    OS << Offset;
1604}
1605
1606//===----------------------------------------------------------------------===//
1607// Symbol Lowering Routines.
1608//===----------------------------------------------------------------------===//
1609
1610/// GetTempSymbol - Return the MCSymbol corresponding to the assembler
1611/// temporary label with the specified stem and unique ID.
1612MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name, unsigned ID) const {
1613  return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
1614                                      Name + Twine(ID));
1615}
1616
1617/// GetTempSymbol - Return an assembler temporary label with the specified
1618/// stem.
1619MCSymbol *AsmPrinter::GetTempSymbol(StringRef Name) const {
1620  return OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix())+
1621                                      Name);
1622}
1623
1624
1625MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1626  return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1627}
1628
1629MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1630  return MMI->getAddrLabelSymbol(BB);
1631}
1632
1633/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1634MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1635  return OutContext.GetOrCreateSymbol
1636    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1637     + "_" + Twine(CPID));
1638}
1639
1640/// GetJTISymbol - Return the symbol for the specified jump table entry.
1641MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1642  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1643}
1644
1645/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1646/// FIXME: privatize to AsmPrinter.
1647MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1648  return OutContext.GetOrCreateSymbol
1649  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1650   Twine(UID) + "_set_" + Twine(MBBID));
1651}
1652
1653/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1654/// global value name as its base, with the specified suffix, and where the
1655/// symbol is forced to have private linkage if ForcePrivate is true.
1656MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1657                                                   StringRef Suffix,
1658                                                   bool ForcePrivate) const {
1659  SmallString<60> NameStr;
1660  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1661  NameStr.append(Suffix.begin(), Suffix.end());
1662  return OutContext.GetOrCreateSymbol(NameStr.str());
1663}
1664
1665/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1666/// ExternalSymbol.
1667MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1668  SmallString<60> NameStr;
1669  Mang->getNameWithPrefix(NameStr, Sym);
1670  return OutContext.GetOrCreateSymbol(NameStr.str());
1671}
1672
1673
1674
1675/// PrintParentLoopComment - Print comments about parent loops of this one.
1676static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1677                                   unsigned FunctionNumber) {
1678  if (Loop == 0) return;
1679  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1680  OS.indent(Loop->getLoopDepth()*2)
1681    << "Parent Loop BB" << FunctionNumber << "_"
1682    << Loop->getHeader()->getNumber()
1683    << " Depth=" << Loop->getLoopDepth() << '\n';
1684}
1685
1686
1687/// PrintChildLoopComment - Print comments about child loops within
1688/// the loop for this basic block, with nesting.
1689static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1690                                  unsigned FunctionNumber) {
1691  // Add child loop information
1692  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1693    OS.indent((*CL)->getLoopDepth()*2)
1694      << "Child Loop BB" << FunctionNumber << "_"
1695      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1696      << '\n';
1697    PrintChildLoopComment(OS, *CL, FunctionNumber);
1698  }
1699}
1700
1701/// EmitBasicBlockLoopComments - Pretty-print comments for basic blocks.
1702static void EmitBasicBlockLoopComments(const MachineBasicBlock &MBB,
1703                                       const MachineLoopInfo *LI,
1704                                       const AsmPrinter &AP) {
1705  // Add loop depth information
1706  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1707  if (Loop == 0) return;
1708
1709  MachineBasicBlock *Header = Loop->getHeader();
1710  assert(Header && "No header for loop");
1711
1712  // If this block is not a loop header, just print out what is the loop header
1713  // and return.
1714  if (Header != &MBB) {
1715    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1716                              Twine(AP.getFunctionNumber())+"_" +
1717                              Twine(Loop->getHeader()->getNumber())+
1718                              " Depth="+Twine(Loop->getLoopDepth()));
1719    return;
1720  }
1721
1722  // Otherwise, it is a loop header.  Print out information about child and
1723  // parent loops.
1724  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1725
1726  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1727
1728  OS << "=>";
1729  OS.indent(Loop->getLoopDepth()*2-2);
1730
1731  OS << "This ";
1732  if (Loop->empty())
1733    OS << "Inner ";
1734  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1735
1736  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1737}
1738
1739
1740/// EmitBasicBlockStart - This method prints the label for the specified
1741/// MachineBasicBlock, an alignment (if present) and a comment describing
1742/// it if appropriate.
1743void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1744  // Emit an alignment directive for this block, if needed.
1745  if (unsigned Align = MBB->getAlignment())
1746    EmitAlignment(Log2_32(Align));
1747
1748  // If the block has its address taken, emit any labels that were used to
1749  // reference the block.  It is possible that there is more than one label
1750  // here, because multiple LLVM BB's may have been RAUW'd to this block after
1751  // the references were generated.
1752  if (MBB->hasAddressTaken()) {
1753    const BasicBlock *BB = MBB->getBasicBlock();
1754    if (isVerbose())
1755      OutStreamer.AddComment("Block address taken");
1756
1757    std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1758
1759    for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1760      OutStreamer.EmitLabel(Syms[i]);
1761  }
1762
1763  // Print the main label for the block.
1764  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1765    if (isVerbose() && OutStreamer.hasRawTextSupport()) {
1766      if (const BasicBlock *BB = MBB->getBasicBlock())
1767        if (BB->hasName())
1768          OutStreamer.AddComment("%" + BB->getName());
1769
1770      EmitBasicBlockLoopComments(*MBB, LI, *this);
1771
1772      // NOTE: Want this comment at start of line, don't emit with AddComment.
1773      OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1774                              Twine(MBB->getNumber()) + ":");
1775    }
1776  } else {
1777    if (isVerbose()) {
1778      if (const BasicBlock *BB = MBB->getBasicBlock())
1779        if (BB->hasName())
1780          OutStreamer.AddComment("%" + BB->getName());
1781      EmitBasicBlockLoopComments(*MBB, LI, *this);
1782    }
1783
1784    OutStreamer.EmitLabel(MBB->getSymbol());
1785  }
1786}
1787
1788void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1789  MCSymbolAttr Attr = MCSA_Invalid;
1790
1791  switch (Visibility) {
1792  default: break;
1793  case GlobalValue::HiddenVisibility:
1794    Attr = MAI->getHiddenVisibilityAttr();
1795    break;
1796  case GlobalValue::ProtectedVisibility:
1797    Attr = MAI->getProtectedVisibilityAttr();
1798    break;
1799  }
1800
1801  if (Attr != MCSA_Invalid)
1802    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1803}
1804
1805/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1806/// exactly one predecessor and the control transfer mechanism between
1807/// the predecessor and this block is a fall-through.
1808bool AsmPrinter::
1809isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB) const {
1810  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1811  // then nothing falls through to it.
1812  if (MBB->isLandingPad() || MBB->pred_empty())
1813    return false;
1814
1815  // If there isn't exactly one predecessor, it can't be a fall through.
1816  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1817  ++PI2;
1818  if (PI2 != MBB->pred_end())
1819    return false;
1820
1821  // The predecessor has to be immediately before this block.
1822  const MachineBasicBlock *Pred = *PI;
1823
1824  if (!Pred->isLayoutSuccessor(MBB))
1825    return false;
1826
1827  // If the block is completely empty, then it definitely does fall through.
1828  if (Pred->empty())
1829    return true;
1830
1831  // Otherwise, check the last instruction.
1832  const MachineInstr &LastInst = Pred->back();
1833  return !LastInst.getDesc().isBarrier();
1834}
1835
1836
1837
1838GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1839  if (!S->usesMetadata())
1840    return 0;
1841
1842  gcp_map_type &GCMap = getGCMap(GCMetadataPrinters);
1843  gcp_map_type::iterator GCPI = GCMap.find(S);
1844  if (GCPI != GCMap.end())
1845    return GCPI->second;
1846
1847  const char *Name = S->getName().c_str();
1848
1849  for (GCMetadataPrinterRegistry::iterator
1850         I = GCMetadataPrinterRegistry::begin(),
1851         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1852    if (strcmp(Name, I->getName()) == 0) {
1853      GCMetadataPrinter *GMP = I->instantiate();
1854      GMP->S = S;
1855      GCMap.insert(std::make_pair(S, GMP));
1856      return GMP;
1857    }
1858
1859  report_fatal_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1860  return 0;
1861}
1862
1863