AsmPrinter.cpp revision 4e972531cf2d719522ab38ce3b5ad1a625579d03 
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/ConstantFolding.h"
29#include "llvm/Analysis/DebugInfo.h"
30#include "llvm/MC/MCContext.h"
31#include "llvm/MC/MCExpr.h"
32#include "llvm/MC/MCInst.h"
33#include "llvm/MC/MCSection.h"
34#include "llvm/MC/MCStreamer.h"
35#include "llvm/MC/MCSymbol.h"
36#include "llvm/MC/MCAsmInfo.h"
37#include "llvm/Target/Mangler.h"
38#include "llvm/Target/TargetData.h"
39#include "llvm/Target/TargetInstrInfo.h"
40#include "llvm/Target/TargetLowering.h"
41#include "llvm/Target/TargetLoweringObjectFile.h"
42#include "llvm/Target/TargetOptions.h"
43#include "llvm/Target/TargetRegisterInfo.h"
44#include "llvm/ADT/SmallPtrSet.h"
45#include "llvm/ADT/SmallString.h"
46#include "llvm/ADT/Statistic.h"
47#include "llvm/Support/CommandLine.h"
48#include "llvm/Support/Debug.h"
49#include "llvm/Support/ErrorHandling.h"
50#include "llvm/Support/Format.h"
51#include "llvm/Support/FormattedStream.h"
52#include <cerrno>
53using namespace llvm;
54
55STATISTIC(EmittedInsts, "Number of machine instrs printed");
56
57char AsmPrinter::ID = 0;
58
59AsmPrinter::AsmPrinter(formatted_raw_ostream &o, TargetMachine &tm,
60                       MCStreamer &Streamer)
61  : MachineFunctionPass(&ID), O(o),
62    TM(tm), MAI(tm.getMCAsmInfo()), TRI(tm.getRegisterInfo()),
63    OutContext(Streamer.getContext()),
64    OutStreamer(Streamer),
65    LastMI(0), LastFn(0), Counter(~0U), SetCounter(0) {
66  DW = 0; MMI = 0;
67  VerboseAsm = Streamer.isVerboseAsm();
68}
69
70AsmPrinter::~AsmPrinter() {
71  for (gcp_iterator I = GCMetadataPrinters.begin(),
72                    E = GCMetadataPrinters.end(); I != E; ++I)
73    delete I->second;
74
75  delete &OutStreamer;
76}
77
78/// getFunctionNumber - Return a unique ID for the current function.
79///
80unsigned AsmPrinter::getFunctionNumber() const {
81  return MF->getFunctionNumber();
82}
83
84TargetLoweringObjectFile &AsmPrinter::getObjFileLowering() const {
85  return TM.getTargetLowering()->getObjFileLowering();
86}
87
88/// getCurrentSection() - Return the current section we are emitting to.
89const MCSection *AsmPrinter::getCurrentSection() const {
90  return OutStreamer.getCurrentSection();
91}
92
93
94void AsmPrinter::getAnalysisUsage(AnalysisUsage &AU) const {
95  AU.setPreservesAll();
96  MachineFunctionPass::getAnalysisUsage(AU);
97  AU.addRequired<MachineModuleInfo>();
98  AU.addRequired<GCModuleInfo>();
99  if (VerboseAsm)
100    AU.addRequired<MachineLoopInfo>();
101}
102
103bool AsmPrinter::doInitialization(Module &M) {
104  MMI = getAnalysisIfAvailable<MachineModuleInfo>();
105  MMI->AnalyzeModule(M);
106
107  // Initialize TargetLoweringObjectFile.
108  const_cast<TargetLoweringObjectFile&>(getObjFileLowering())
109    .Initialize(OutContext, TM);
110
111  Mang = new Mangler(OutContext, *TM.getTargetData());
112
113  // Allow the target to emit any magic that it wants at the start of the file.
114  EmitStartOfAsmFile(M);
115
116  // Very minimal debug info. It is ignored if we emit actual debug info. If we
117  // don't, this at least helps the user find where a global came from.
118  if (MAI->hasSingleParameterDotFile()) {
119    // .file "foo.c"
120    OutStreamer.EmitFileDirective(M.getModuleIdentifier());
121  }
122
123  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
124  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
125  for (GCModuleInfo::iterator I = MI->begin(), E = MI->end(); I != E; ++I)
126    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*I))
127      MP->beginAssembly(O, *this, *MAI);
128
129  // Emit module-level inline asm if it exists.
130  if (!M.getModuleInlineAsm().empty()) {
131    OutStreamer.AddComment("Start of file scope inline assembly");
132    OutStreamer.AddBlankLine();
133    EmitInlineAsm(M.getModuleInlineAsm());
134    OutStreamer.AddComment("End of file scope inline assembly");
135    OutStreamer.AddBlankLine();
136  }
137
138  DW = getAnalysisIfAvailable<DwarfWriter>();
139  if (DW)
140    DW->BeginModule(&M, MMI, O, this, MAI);
141
142  return false;
143}
144
145void AsmPrinter::EmitLinkage(unsigned Linkage, MCSymbol *GVSym) const {
146  switch ((GlobalValue::LinkageTypes)Linkage) {
147  case GlobalValue::CommonLinkage:
148  case GlobalValue::LinkOnceAnyLinkage:
149  case GlobalValue::LinkOnceODRLinkage:
150  case GlobalValue::WeakAnyLinkage:
151  case GlobalValue::WeakODRLinkage:
152  case GlobalValue::LinkerPrivateLinkage:
153    if (MAI->getWeakDefDirective() != 0) {
154      // .globl _foo
155      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
156      // .weak_definition _foo
157      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_WeakDefinition);
158    } else if (const char *LinkOnce = MAI->getLinkOnceDirective()) {
159      // .globl _foo
160      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
161      // FIXME: linkonce should be a section attribute, handled by COFF Section
162      // assignment.
163      // http://sourceware.org/binutils/docs-2.20/as/Linkonce.html#Linkonce
164      // .linkonce discard
165      // FIXME: It would be nice to use .linkonce samesize for non-common
166      // globals.
167      OutStreamer.EmitRawText(StringRef(LinkOnce));
168    } else {
169      // .weak _foo
170      OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Weak);
171    }
172    break;
173  case GlobalValue::DLLExportLinkage:
174  case GlobalValue::AppendingLinkage:
175    // FIXME: appending linkage variables should go into a section of
176    // their name or something.  For now, just emit them as external.
177  case GlobalValue::ExternalLinkage:
178    // If external or appending, declare as a global symbol.
179    // .globl _foo
180    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
181    break;
182  case GlobalValue::PrivateLinkage:
183  case GlobalValue::InternalLinkage:
184    break;
185  default:
186    llvm_unreachable("Unknown linkage type!");
187  }
188}
189
190
191/// EmitGlobalVariable - Emit the specified global variable to the .s file.
192void AsmPrinter::EmitGlobalVariable(const GlobalVariable *GV) {
193  if (!GV->hasInitializer())   // External globals require no code.
194    return;
195
196  // Check to see if this is a special global used by LLVM, if so, emit it.
197  if (EmitSpecialLLVMGlobal(GV))
198    return;
199
200  MCSymbol *GVSym = Mang->getSymbol(GV);
201  EmitVisibility(GVSym, GV->getVisibility());
202
203  if (MAI->hasDotTypeDotSizeDirective())
204    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_ELF_TypeObject);
205
206  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, TM);
207
208  const TargetData *TD = TM.getTargetData();
209  unsigned Size = TD->getTypeAllocSize(GV->getType()->getElementType());
210  unsigned AlignLog = TD->getPreferredAlignmentLog(GV);
211
212  // Handle common and BSS local symbols (.lcomm).
213  if (GVKind.isCommon() || GVKind.isBSSLocal()) {
214    if (Size == 0) Size = 1;   // .comm Foo, 0 is undefined, avoid it.
215
216    if (VerboseAsm) {
217      WriteAsOperand(OutStreamer.GetCommentOS(), GV,
218                     /*PrintType=*/false, GV->getParent());
219      OutStreamer.GetCommentOS() << '\n';
220    }
221
222    // Handle common symbols.
223    if (GVKind.isCommon()) {
224      // .comm _foo, 42, 4
225      OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
226      return;
227    }
228
229    // Handle local BSS symbols.
230    if (MAI->hasMachoZeroFillDirective()) {
231      const MCSection *TheSection =
232        getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
233      // .zerofill __DATA, __bss, _foo, 400, 5
234      OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
235      return;
236    }
237
238    if (MAI->hasLCOMMDirective()) {
239      // .lcomm _foo, 42
240      OutStreamer.EmitLocalCommonSymbol(GVSym, Size);
241      return;
242    }
243
244    // .local _foo
245    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Local);
246    // .comm _foo, 42, 4
247    OutStreamer.EmitCommonSymbol(GVSym, Size, 1 << AlignLog);
248    return;
249  }
250
251  const MCSection *TheSection =
252    getObjFileLowering().SectionForGlobal(GV, GVKind, Mang, TM);
253
254  // Handle the zerofill directive on darwin, which is a special form of BSS
255  // emission.
256  if (GVKind.isBSSExtern() && MAI->hasMachoZeroFillDirective()) {
257    // .globl _foo
258    OutStreamer.EmitSymbolAttribute(GVSym, MCSA_Global);
259    // .zerofill __DATA, __common, _foo, 400, 5
260    OutStreamer.EmitZerofill(TheSection, GVSym, Size, 1 << AlignLog);
261    return;
262  }
263
264  OutStreamer.SwitchSection(TheSection);
265
266  EmitLinkage(GV->getLinkage(), GVSym);
267  EmitAlignment(AlignLog, GV);
268
269  if (VerboseAsm) {
270    WriteAsOperand(OutStreamer.GetCommentOS(), GV,
271                   /*PrintType=*/false, GV->getParent());
272    OutStreamer.GetCommentOS() << '\n';
273  }
274  OutStreamer.EmitLabel(GVSym);
275
276  EmitGlobalConstant(GV->getInitializer());
277
278  if (MAI->hasDotTypeDotSizeDirective())
279    // .size foo, 42
280    OutStreamer.EmitELFSize(GVSym, MCConstantExpr::Create(Size, OutContext));
281
282  OutStreamer.AddBlankLine();
283}
284
285/// EmitFunctionHeader - This method emits the header for the current
286/// function.
287void AsmPrinter::EmitFunctionHeader() {
288  // Print out constants referenced by the function
289  EmitConstantPool();
290
291  // Print the 'header' of function.
292  const Function *F = MF->getFunction();
293
294  OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F, Mang, TM));
295  EmitVisibility(CurrentFnSym, F->getVisibility());
296
297  EmitLinkage(F->getLinkage(), CurrentFnSym);
298  EmitAlignment(MF->getAlignment(), F);
299
300  if (MAI->hasDotTypeDotSizeDirective())
301    OutStreamer.EmitSymbolAttribute(CurrentFnSym, MCSA_ELF_TypeFunction);
302
303  if (VerboseAsm) {
304    WriteAsOperand(OutStreamer.GetCommentOS(), F,
305                   /*PrintType=*/false, F->getParent());
306    OutStreamer.GetCommentOS() << '\n';
307  }
308
309  // Emit the CurrentFnSym.  This is a virtual function to allow targets to
310  // do their wild and crazy things as required.
311  EmitFunctionEntryLabel();
312
313  // If the function had address-taken blocks that got deleted, then we have
314  // references to the dangling symbols.  Emit them at the start of the function
315  // so that we don't get references to undefined symbols.
316  std::vector<MCSymbol*> DeadBlockSyms;
317  MMI->takeDeletedSymbolsForFunction(F, DeadBlockSyms);
318  for (unsigned i = 0, e = DeadBlockSyms.size(); i != e; ++i) {
319    OutStreamer.AddComment("Address taken block that was later removed");
320    OutStreamer.EmitLabel(DeadBlockSyms[i]);
321  }
322
323  // Add some workaround for linkonce linkage on Cygwin\MinGW.
324  if (MAI->getLinkOnceDirective() != 0 &&
325      (F->hasLinkOnceLinkage() || F->hasWeakLinkage())) {
326    // FIXME: What is this?
327    MCSymbol *FakeStub =
328      OutContext.GetOrCreateSymbol(Twine("Lllvm$workaround$fake$stub$")+
329                                   CurrentFnSym->getName());
330    OutStreamer.EmitLabel(FakeStub);
331  }
332
333  // Emit pre-function debug and/or EH information.
334  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
335    DW->BeginFunction(MF);
336}
337
338/// EmitFunctionEntryLabel - Emit the label that is the entrypoint for the
339/// function.  This can be overridden by targets as required to do custom stuff.
340void AsmPrinter::EmitFunctionEntryLabel() {
341  OutStreamer.EmitLabel(CurrentFnSym);
342}
343
344
345/// EmitComments - Pretty-print comments for instructions.
346static void EmitComments(const MachineInstr &MI, raw_ostream &CommentOS) {
347  const MachineFunction *MF = MI.getParent()->getParent();
348  const TargetMachine &TM = MF->getTarget();
349
350  DebugLoc DL = MI.getDebugLoc();
351  if (!DL.isUnknown()) {          // Print source line info.
352    DIScope Scope(DL.getScope(MF->getFunction()->getContext()));
353    // Omit the directory, because it's likely to be long and uninteresting.
354    if (Scope.Verify())
355      CommentOS << Scope.getFilename();
356    else
357      CommentOS << "<unknown>";
358    CommentOS << ':' << DL.getLine();
359    if (DL.getCol() != 0)
360      CommentOS << ':' << DL.getCol();
361    CommentOS << '\n';
362  }
363
364  // Check for spills and reloads
365  int FI;
366
367  const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
368
369  // We assume a single instruction only has a spill or reload, not
370  // both.
371  const MachineMemOperand *MMO;
372  if (TM.getInstrInfo()->isLoadFromStackSlotPostFE(&MI, FI)) {
373    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
374      MMO = *MI.memoperands_begin();
375      CommentOS << MMO->getSize() << "-byte Reload\n";
376    }
377  } else if (TM.getInstrInfo()->hasLoadFromStackSlot(&MI, MMO, FI)) {
378    if (FrameInfo->isSpillSlotObjectIndex(FI))
379      CommentOS << MMO->getSize() << "-byte Folded Reload\n";
380  } else if (TM.getInstrInfo()->isStoreToStackSlotPostFE(&MI, FI)) {
381    if (FrameInfo->isSpillSlotObjectIndex(FI)) {
382      MMO = *MI.memoperands_begin();
383      CommentOS << MMO->getSize() << "-byte Spill\n";
384    }
385  } else if (TM.getInstrInfo()->hasStoreToStackSlot(&MI, MMO, FI)) {
386    if (FrameInfo->isSpillSlotObjectIndex(FI))
387      CommentOS << MMO->getSize() << "-byte Folded Spill\n";
388  }
389
390  // Check for spill-induced copies
391  unsigned SrcReg, DstReg, SrcSubIdx, DstSubIdx;
392  if (TM.getInstrInfo()->isMoveInstr(MI, SrcReg, DstReg,
393                                     SrcSubIdx, DstSubIdx)) {
394    if (MI.getAsmPrinterFlag(MachineInstr::ReloadReuse))
395      CommentOS << " Reload Reuse\n";
396  }
397}
398
399
400
401/// EmitFunctionBody - This method emits the body and trailer for a
402/// function.
403void AsmPrinter::EmitFunctionBody() {
404  // Emit target-specific gunk before the function body.
405  EmitFunctionBodyStart();
406
407  // Print out code for the function.
408  bool HasAnyRealCode = false;
409  for (MachineFunction::const_iterator I = MF->begin(), E = MF->end();
410       I != E; ++I) {
411    // Print a label for the basic block.
412    EmitBasicBlockStart(I);
413    for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
414         II != IE; ++II) {
415      // Print the assembly for the instruction.
416      if (!II->isLabel())
417        HasAnyRealCode = true;
418
419      ++EmittedInsts;
420
421      // FIXME: Clean up processDebugLoc.
422      processDebugLoc(II, true);
423
424      if (VerboseAsm)
425        EmitComments(*II, OutStreamer.GetCommentOS());
426
427      switch (II->getOpcode()) {
428      case TargetOpcode::DBG_LABEL:
429      case TargetOpcode::EH_LABEL:
430      case TargetOpcode::GC_LABEL:
431        printLabelInst(II);
432        break;
433      case TargetOpcode::INLINEASM:
434        printInlineAsm(II);
435        break;
436      case TargetOpcode::IMPLICIT_DEF:
437        printImplicitDef(II);
438        break;
439      case TargetOpcode::KILL:
440        printKill(II);
441        break;
442      default:
443        EmitInstruction(II);
444        break;
445      }
446
447      // FIXME: Clean up processDebugLoc.
448      processDebugLoc(II, false);
449    }
450  }
451
452  // If the function is empty and the object file uses .subsections_via_symbols,
453  // then we need to emit *something* to the function body to prevent the
454  // labels from collapsing together.  Just emit a 0 byte.
455  if (MAI->hasSubsectionsViaSymbols() && !HasAnyRealCode)
456    OutStreamer.EmitIntValue(0, 1, 0/*addrspace*/);
457
458  // Emit target-specific gunk after the function body.
459  EmitFunctionBodyEnd();
460
461  // If the target wants a .size directive for the size of the function, emit
462  // it.
463  if (MAI->hasDotTypeDotSizeDirective()) {
464    // Create a symbol for the end of function, so we can get the size as
465    // difference between the function label and the temp label.
466    MCSymbol *FnEndLabel = OutContext.CreateTempSymbol();
467    OutStreamer.EmitLabel(FnEndLabel);
468
469    const MCExpr *SizeExp =
470      MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(FnEndLabel, OutContext),
471                              MCSymbolRefExpr::Create(CurrentFnSym, OutContext),
472                              OutContext);
473    OutStreamer.EmitELFSize(CurrentFnSym, SizeExp);
474  }
475
476  // Emit post-function debug information.
477  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
478    DW->EndFunction(MF);
479
480  // Print out jump tables referenced by the function.
481  EmitJumpTableInfo();
482
483  OutStreamer.AddBlankLine();
484}
485
486
487bool AsmPrinter::doFinalization(Module &M) {
488  // Emit global variables.
489  for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
490       I != E; ++I)
491    EmitGlobalVariable(I);
492
493  // Emit final debug information.
494  if (MAI->doesSupportDebugInformation() || MAI->doesSupportExceptionHandling())
495    DW->EndModule();
496
497  // If the target wants to know about weak references, print them all.
498  if (MAI->getWeakRefDirective()) {
499    // FIXME: This is not lazy, it would be nice to only print weak references
500    // to stuff that is actually used.  Note that doing so would require targets
501    // to notice uses in operands (due to constant exprs etc).  This should
502    // happen with the MC stuff eventually.
503
504    // Print out module-level global variables here.
505    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
506         I != E; ++I) {
507      if (!I->hasExternalWeakLinkage()) continue;
508      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
509    }
510
511    for (Module::const_iterator I = M.begin(), E = M.end(); I != E; ++I) {
512      if (!I->hasExternalWeakLinkage()) continue;
513      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(I), MCSA_WeakReference);
514    }
515  }
516
517  if (MAI->hasSetDirective()) {
518    OutStreamer.AddBlankLine();
519    for (Module::const_alias_iterator I = M.alias_begin(), E = M.alias_end();
520         I != E; ++I) {
521      MCSymbol *Name = Mang->getSymbol(I);
522
523      const GlobalValue *GV = cast<GlobalValue>(I->getAliasedGlobal());
524      MCSymbol *Target = Mang->getSymbol(GV);
525
526      if (I->hasExternalLinkage() || !MAI->getWeakRefDirective())
527        OutStreamer.EmitSymbolAttribute(Name, MCSA_Global);
528      else if (I->hasWeakLinkage())
529        OutStreamer.EmitSymbolAttribute(Name, MCSA_WeakReference);
530      else
531        assert(I->hasLocalLinkage() && "Invalid alias linkage");
532
533      EmitVisibility(Name, I->getVisibility());
534
535      // Emit the directives as assignments aka .set:
536      OutStreamer.EmitAssignment(Name,
537                                 MCSymbolRefExpr::Create(Target, OutContext));
538    }
539  }
540
541  GCModuleInfo *MI = getAnalysisIfAvailable<GCModuleInfo>();
542  assert(MI && "AsmPrinter didn't require GCModuleInfo?");
543  for (GCModuleInfo::iterator I = MI->end(), E = MI->begin(); I != E; )
544    if (GCMetadataPrinter *MP = GetOrCreateGCPrinter(*--I))
545      MP->finishAssembly(O, *this, *MAI);
546
547  // If we don't have any trampolines, then we don't require stack memory
548  // to be executable. Some targets have a directive to declare this.
549  Function *InitTrampolineIntrinsic = M.getFunction("llvm.init.trampoline");
550  if (!InitTrampolineIntrinsic || InitTrampolineIntrinsic->use_empty())
551    if (MCSection *S = MAI->getNonexecutableStackSection(OutContext))
552      OutStreamer.SwitchSection(S);
553
554  // Allow the target to emit any magic that it wants at the end of the file,
555  // after everything else has gone out.
556  EmitEndOfAsmFile(M);
557
558  delete Mang; Mang = 0;
559  DW = 0; MMI = 0;
560
561  OutStreamer.Finish();
562  return false;
563}
564
565void AsmPrinter::SetupMachineFunction(MachineFunction &MF) {
566  this->MF = &MF;
567  // Get the function symbol.
568  CurrentFnSym = Mang->getSymbol(MF.getFunction());
569
570  if (VerboseAsm)
571    LI = &getAnalysis<MachineLoopInfo>();
572}
573
574namespace {
575  // SectionCPs - Keep track the alignment, constpool entries per Section.
576  struct SectionCPs {
577    const MCSection *S;
578    unsigned Alignment;
579    SmallVector<unsigned, 4> CPEs;
580    SectionCPs(const MCSection *s, unsigned a) : S(s), Alignment(a) {}
581  };
582}
583
584/// EmitConstantPool - Print to the current output stream assembly
585/// representations of the constants in the constant pool MCP. This is
586/// used to print out constants which have been "spilled to memory" by
587/// the code generator.
588///
589void AsmPrinter::EmitConstantPool() {
590  const MachineConstantPool *MCP = MF->getConstantPool();
591  const std::vector<MachineConstantPoolEntry> &CP = MCP->getConstants();
592  if (CP.empty()) return;
593
594  // Calculate sections for constant pool entries. We collect entries to go into
595  // the same section together to reduce amount of section switch statements.
596  SmallVector<SectionCPs, 4> CPSections;
597  for (unsigned i = 0, e = CP.size(); i != e; ++i) {
598    const MachineConstantPoolEntry &CPE = CP[i];
599    unsigned Align = CPE.getAlignment();
600
601    SectionKind Kind;
602    switch (CPE.getRelocationInfo()) {
603    default: llvm_unreachable("Unknown section kind");
604    case 2: Kind = SectionKind::getReadOnlyWithRel(); break;
605    case 1:
606      Kind = SectionKind::getReadOnlyWithRelLocal();
607      break;
608    case 0:
609    switch (TM.getTargetData()->getTypeAllocSize(CPE.getType())) {
610    case 4:  Kind = SectionKind::getMergeableConst4(); break;
611    case 8:  Kind = SectionKind::getMergeableConst8(); break;
612    case 16: Kind = SectionKind::getMergeableConst16();break;
613    default: Kind = SectionKind::getMergeableConst(); break;
614    }
615    }
616
617    const MCSection *S = getObjFileLowering().getSectionForConstant(Kind);
618
619    // The number of sections are small, just do a linear search from the
620    // last section to the first.
621    bool Found = false;
622    unsigned SecIdx = CPSections.size();
623    while (SecIdx != 0) {
624      if (CPSections[--SecIdx].S == S) {
625        Found = true;
626        break;
627      }
628    }
629    if (!Found) {
630      SecIdx = CPSections.size();
631      CPSections.push_back(SectionCPs(S, Align));
632    }
633
634    if (Align > CPSections[SecIdx].Alignment)
635      CPSections[SecIdx].Alignment = Align;
636    CPSections[SecIdx].CPEs.push_back(i);
637  }
638
639  // Now print stuff into the calculated sections.
640  for (unsigned i = 0, e = CPSections.size(); i != e; ++i) {
641    OutStreamer.SwitchSection(CPSections[i].S);
642    EmitAlignment(Log2_32(CPSections[i].Alignment));
643
644    unsigned Offset = 0;
645    for (unsigned j = 0, ee = CPSections[i].CPEs.size(); j != ee; ++j) {
646      unsigned CPI = CPSections[i].CPEs[j];
647      MachineConstantPoolEntry CPE = CP[CPI];
648
649      // Emit inter-object padding for alignment.
650      unsigned AlignMask = CPE.getAlignment() - 1;
651      unsigned NewOffset = (Offset + AlignMask) & ~AlignMask;
652      OutStreamer.EmitFill(NewOffset - Offset, 0/*fillval*/, 0/*addrspace*/);
653
654      const Type *Ty = CPE.getType();
655      Offset = NewOffset + TM.getTargetData()->getTypeAllocSize(Ty);
656
657      // Emit the label with a comment on it.
658      if (VerboseAsm) {
659        OutStreamer.GetCommentOS() << "constant pool ";
660        WriteTypeSymbolic(OutStreamer.GetCommentOS(), CPE.getType(),
661                          MF->getFunction()->getParent());
662        OutStreamer.GetCommentOS() << '\n';
663      }
664      OutStreamer.EmitLabel(GetCPISymbol(CPI));
665
666      if (CPE.isMachineConstantPoolEntry())
667        EmitMachineConstantPoolValue(CPE.Val.MachineCPVal);
668      else
669        EmitGlobalConstant(CPE.Val.ConstVal);
670    }
671  }
672}
673
674/// EmitJumpTableInfo - Print assembly representations of the jump tables used
675/// by the current function to the current output stream.
676///
677void AsmPrinter::EmitJumpTableInfo() {
678  const MachineJumpTableInfo *MJTI = MF->getJumpTableInfo();
679  if (MJTI == 0) return;
680  if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline) return;
681  const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
682  if (JT.empty()) return;
683
684  // Pick the directive to use to print the jump table entries, and switch to
685  // the appropriate section.
686  const Function *F = MF->getFunction();
687  bool JTInDiffSection = false;
688  if (// In PIC mode, we need to emit the jump table to the same section as the
689      // function body itself, otherwise the label differences won't make sense.
690      // FIXME: Need a better predicate for this: what about custom entries?
691      MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 ||
692      // We should also do if the section name is NULL or function is declared
693      // in discardable section
694      // FIXME: this isn't the right predicate, should be based on the MCSection
695      // for the function.
696      F->isWeakForLinker()) {
697    OutStreamer.SwitchSection(getObjFileLowering().SectionForGlobal(F,Mang,TM));
698  } else {
699    // Otherwise, drop it in the readonly section.
700    const MCSection *ReadOnlySection =
701      getObjFileLowering().getSectionForConstant(SectionKind::getReadOnly());
702    OutStreamer.SwitchSection(ReadOnlySection);
703    JTInDiffSection = true;
704  }
705
706  EmitAlignment(Log2_32(MJTI->getEntryAlignment(*TM.getTargetData())));
707
708  for (unsigned JTI = 0, e = JT.size(); JTI != e; ++JTI) {
709    const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
710
711    // If this jump table was deleted, ignore it.
712    if (JTBBs.empty()) continue;
713
714    // For the EK_LabelDifference32 entry, if the target supports .set, emit a
715    // .set directive for each unique entry.  This reduces the number of
716    // relocations the assembler will generate for the jump table.
717    if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_LabelDifference32 &&
718        MAI->hasSetDirective()) {
719      SmallPtrSet<const MachineBasicBlock*, 16> EmittedSets;
720      const TargetLowering *TLI = TM.getTargetLowering();
721      const MCExpr *Base = TLI->getPICJumpTableRelocBaseExpr(MF,JTI,OutContext);
722      for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii) {
723        const MachineBasicBlock *MBB = JTBBs[ii];
724        if (!EmittedSets.insert(MBB)) continue;
725
726        // .set LJTSet, LBB32-base
727        const MCExpr *LHS =
728          MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
729        OutStreamer.EmitAssignment(GetJTSetSymbol(JTI, MBB->getNumber()),
730                                MCBinaryExpr::CreateSub(LHS, Base, OutContext));
731      }
732    }
733
734    // On some targets (e.g. Darwin) we want to emit two consequtive labels
735    // before each jump table.  The first label is never referenced, but tells
736    // the assembler and linker the extents of the jump table object.  The
737    // second label is actually referenced by the code.
738    if (JTInDiffSection && MAI->getLinkerPrivateGlobalPrefix()[0])
739      // FIXME: This doesn't have to have any specific name, just any randomly
740      // named and numbered 'l' label would work.  Simplify GetJTISymbol.
741      OutStreamer.EmitLabel(GetJTISymbol(JTI, true));
742
743    OutStreamer.EmitLabel(GetJTISymbol(JTI));
744
745    for (unsigned ii = 0, ee = JTBBs.size(); ii != ee; ++ii)
746      EmitJumpTableEntry(MJTI, JTBBs[ii], JTI);
747  }
748}
749
750/// EmitJumpTableEntry - Emit a jump table entry for the specified MBB to the
751/// current stream.
752void AsmPrinter::EmitJumpTableEntry(const MachineJumpTableInfo *MJTI,
753                                    const MachineBasicBlock *MBB,
754                                    unsigned UID) const {
755  const MCExpr *Value = 0;
756  switch (MJTI->getEntryKind()) {
757  case MachineJumpTableInfo::EK_Inline:
758    llvm_unreachable("Cannot emit EK_Inline jump table entry"); break;
759  case MachineJumpTableInfo::EK_Custom32:
760    Value = TM.getTargetLowering()->LowerCustomJumpTableEntry(MJTI, MBB, UID,
761                                                              OutContext);
762    break;
763  case MachineJumpTableInfo::EK_BlockAddress:
764    // EK_BlockAddress - Each entry is a plain address of block, e.g.:
765    //     .word LBB123
766    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
767    break;
768  case MachineJumpTableInfo::EK_GPRel32BlockAddress: {
769    // EK_GPRel32BlockAddress - Each entry is an address of block, encoded
770    // with a relocation as gp-relative, e.g.:
771    //     .gprel32 LBB123
772    MCSymbol *MBBSym = MBB->getSymbol();
773    OutStreamer.EmitGPRel32Value(MCSymbolRefExpr::Create(MBBSym, OutContext));
774    return;
775  }
776
777  case MachineJumpTableInfo::EK_LabelDifference32: {
778    // EK_LabelDifference32 - Each entry is the address of the block minus
779    // the address of the jump table.  This is used for PIC jump tables where
780    // gprel32 is not supported.  e.g.:
781    //      .word LBB123 - LJTI1_2
782    // If the .set directive is supported, this is emitted as:
783    //      .set L4_5_set_123, LBB123 - LJTI1_2
784    //      .word L4_5_set_123
785
786    // If we have emitted set directives for the jump table entries, print
787    // them rather than the entries themselves.  If we're emitting PIC, then
788    // emit the table entries as differences between two text section labels.
789    if (MAI->hasSetDirective()) {
790      // If we used .set, reference the .set's symbol.
791      Value = MCSymbolRefExpr::Create(GetJTSetSymbol(UID, MBB->getNumber()),
792                                      OutContext);
793      break;
794    }
795    // Otherwise, use the difference as the jump table entry.
796    Value = MCSymbolRefExpr::Create(MBB->getSymbol(), OutContext);
797    const MCExpr *JTI = MCSymbolRefExpr::Create(GetJTISymbol(UID), OutContext);
798    Value = MCBinaryExpr::CreateSub(Value, JTI, OutContext);
799    break;
800  }
801  }
802
803  assert(Value && "Unknown entry kind!");
804
805  unsigned EntrySize = MJTI->getEntrySize(*TM.getTargetData());
806  OutStreamer.EmitValue(Value, EntrySize, /*addrspace*/0);
807}
808
809
810/// EmitSpecialLLVMGlobal - Check to see if the specified global is a
811/// special global used by LLVM.  If so, emit it and return true, otherwise
812/// do nothing and return false.
813bool AsmPrinter::EmitSpecialLLVMGlobal(const GlobalVariable *GV) {
814  if (GV->getName() == "llvm.used") {
815    if (MAI->hasNoDeadStrip())    // No need to emit this at all.
816      EmitLLVMUsedList(GV->getInitializer());
817    return true;
818  }
819
820  // Ignore debug and non-emitted data.  This handles llvm.compiler.used.
821  if (GV->getSection() == "llvm.metadata" ||
822      GV->hasAvailableExternallyLinkage())
823    return true;
824
825  if (!GV->hasAppendingLinkage()) return false;
826
827  assert(GV->hasInitializer() && "Not a special LLVM global!");
828
829  const TargetData *TD = TM.getTargetData();
830  unsigned Align = Log2_32(TD->getPointerPrefAlignment());
831  if (GV->getName() == "llvm.global_ctors") {
832    OutStreamer.SwitchSection(getObjFileLowering().getStaticCtorSection());
833    EmitAlignment(Align, 0);
834    EmitXXStructorList(GV->getInitializer());
835
836    if (TM.getRelocationModel() == Reloc::Static &&
837        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
838      StringRef Sym(".constructors_used");
839      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
840                                      MCSA_Reference);
841    }
842    return true;
843  }
844
845  if (GV->getName() == "llvm.global_dtors") {
846    OutStreamer.SwitchSection(getObjFileLowering().getStaticDtorSection());
847    EmitAlignment(Align, 0);
848    EmitXXStructorList(GV->getInitializer());
849
850    if (TM.getRelocationModel() == Reloc::Static &&
851        MAI->hasStaticCtorDtorReferenceInStaticMode()) {
852      StringRef Sym(".destructors_used");
853      OutStreamer.EmitSymbolAttribute(OutContext.GetOrCreateSymbol(Sym),
854                                      MCSA_Reference);
855    }
856    return true;
857  }
858
859  return false;
860}
861
862/// EmitLLVMUsedList - For targets that define a MAI::UsedDirective, mark each
863/// global in the specified llvm.used list for which emitUsedDirectiveFor
864/// is true, as being used with this directive.
865void AsmPrinter::EmitLLVMUsedList(Constant *List) {
866  // Should be an array of 'i8*'.
867  ConstantArray *InitList = dyn_cast<ConstantArray>(List);
868  if (InitList == 0) return;
869
870  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
871    const GlobalValue *GV =
872      dyn_cast<GlobalValue>(InitList->getOperand(i)->stripPointerCasts());
873    if (GV && getObjFileLowering().shouldEmitUsedDirectiveFor(GV, Mang))
874      OutStreamer.EmitSymbolAttribute(Mang->getSymbol(GV), MCSA_NoDeadStrip);
875  }
876}
877
878/// EmitXXStructorList - Emit the ctor or dtor list.  This just prints out the
879/// function pointers, ignoring the init priority.
880void AsmPrinter::EmitXXStructorList(Constant *List) {
881  // Should be an array of '{ int, void ()* }' structs.  The first value is the
882  // init priority, which we ignore.
883  if (!isa<ConstantArray>(List)) return;
884  ConstantArray *InitList = cast<ConstantArray>(List);
885  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i)
886    if (ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i))){
887      if (CS->getNumOperands() != 2) return;  // Not array of 2-element structs.
888
889      if (CS->getOperand(1)->isNullValue())
890        return;  // Found a null terminator, exit printing.
891      // Emit the function pointer.
892      EmitGlobalConstant(CS->getOperand(1));
893    }
894}
895
896/// EmitInlineAsm - Emit a blob of inline asm to the output streamer.
897void AsmPrinter::EmitInlineAsm(StringRef Str) const {
898  assert(!Str.empty() && "Can't emit empty inline asm block");
899
900  // If the output streamer is actually a .s file, just emit the blob textually.
901  // This is useful in case the asm parser doesn't handle something but the
902  // system assembler does.
903  if (OutStreamer.hasRawTextSupport()) {
904    OutStreamer.EmitRawText(Str);
905    return;
906  }
907
908  errs() << "Inline asm not supported by this streamer!\n";
909}
910
911
912//===--------------------------------------------------------------------===//
913// Emission and print routines
914//
915
916/// EmitInt8 - Emit a byte directive and value.
917///
918void AsmPrinter::EmitInt8(int Value) const {
919  OutStreamer.EmitIntValue(Value, 1, 0/*addrspace*/);
920}
921
922/// EmitInt16 - Emit a short directive and value.
923///
924void AsmPrinter::EmitInt16(int Value) const {
925  OutStreamer.EmitIntValue(Value, 2, 0/*addrspace*/);
926}
927
928/// EmitInt32 - Emit a long directive and value.
929///
930void AsmPrinter::EmitInt32(int Value) const {
931  OutStreamer.EmitIntValue(Value, 4, 0/*addrspace*/);
932}
933
934/// EmitLabelDifference - Emit something like ".long Hi-Lo" where the size
935/// in bytes of the directive is specified by Size and Hi/Lo specify the
936/// labels.  This implicitly uses .set if it is available.
937void AsmPrinter::EmitLabelDifference(const MCSymbol *Hi, const MCSymbol *Lo,
938                                     unsigned Size) const {
939  // Get the Hi-Lo expression.
940  const MCExpr *Diff =
941    MCBinaryExpr::CreateSub(MCSymbolRefExpr::Create(Hi, OutContext),
942                            MCSymbolRefExpr::Create(Lo, OutContext),
943                            OutContext);
944
945  if (!MAI->hasSetDirective()) {
946    OutStreamer.EmitValue(Diff, Size, 0/*AddrSpace*/);
947    return;
948  }
949
950  // Otherwise, emit with .set (aka assignment).
951  MCSymbol *SetLabel =
952    OutContext.GetOrCreateSymbol(Twine(MAI->getPrivateGlobalPrefix()) +
953                                 "set" + Twine(SetCounter++));
954  OutStreamer.EmitAssignment(SetLabel, Diff);
955  OutStreamer.EmitSymbolValue(SetLabel, Size, 0/*AddrSpace*/);
956}
957
958
959//===----------------------------------------------------------------------===//
960
961// EmitAlignment - Emit an alignment directive to the specified power of
962// two boundary.  For example, if you pass in 3 here, you will get an 8
963// byte alignment.  If a global value is specified, and if that global has
964// an explicit alignment requested, it will unconditionally override the
965// alignment request.  However, if ForcedAlignBits is specified, this value
966// has final say: the ultimate alignment will be the max of ForcedAlignBits
967// and the alignment computed with NumBits and the global.
968//
969// The algorithm is:
970//     Align = NumBits;
971//     if (GV && GV->hasalignment) Align = GV->getalignment();
972//     Align = std::max(Align, ForcedAlignBits);
973//
974void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
975                               unsigned ForcedAlignBits,
976                               bool UseFillExpr) const {
977  if (GV && GV->getAlignment())
978    NumBits = Log2_32(GV->getAlignment());
979  NumBits = std::max(NumBits, ForcedAlignBits);
980
981  if (NumBits == 0) return;   // No need to emit alignment.
982
983  if (getCurrentSection()->getKind().isText())
984    OutStreamer.EmitCodeAlignment(1 << NumBits);
985  else
986    OutStreamer.EmitValueToAlignment(1 << NumBits, 0, 1, 0);
987}
988
989/// LowerConstant - Lower the specified LLVM Constant to an MCExpr.
990///
991static const MCExpr *LowerConstant(const Constant *CV, AsmPrinter &AP) {
992  MCContext &Ctx = AP.OutContext;
993
994  if (CV->isNullValue() || isa<UndefValue>(CV))
995    return MCConstantExpr::Create(0, Ctx);
996
997  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV))
998    return MCConstantExpr::Create(CI->getZExtValue(), Ctx);
999
1000  if (const GlobalValue *GV = dyn_cast<GlobalValue>(CV))
1001    return MCSymbolRefExpr::Create(AP.Mang->getSymbol(GV), Ctx);
1002  if (const BlockAddress *BA = dyn_cast<BlockAddress>(CV))
1003    return MCSymbolRefExpr::Create(AP.GetBlockAddressSymbol(BA), Ctx);
1004
1005  const ConstantExpr *CE = dyn_cast<ConstantExpr>(CV);
1006  if (CE == 0) {
1007    llvm_unreachable("Unknown constant value to lower!");
1008    return MCConstantExpr::Create(0, Ctx);
1009  }
1010
1011  switch (CE->getOpcode()) {
1012  default:
1013    // If the code isn't optimized, there may be outstanding folding
1014    // opportunities. Attempt to fold the expression using TargetData as a
1015    // last resort before giving up.
1016    if (Constant *C =
1017          ConstantFoldConstantExpression(CE, AP.TM.getTargetData()))
1018      if (C != CE)
1019        return LowerConstant(C, AP);
1020#ifndef NDEBUG
1021    CE->dump();
1022#endif
1023    llvm_unreachable("FIXME: Don't support this constant expr");
1024  case Instruction::GetElementPtr: {
1025    const TargetData &TD = *AP.TM.getTargetData();
1026    // Generate a symbolic expression for the byte address
1027    const Constant *PtrVal = CE->getOperand(0);
1028    SmallVector<Value*, 8> IdxVec(CE->op_begin()+1, CE->op_end());
1029    int64_t Offset = TD.getIndexedOffset(PtrVal->getType(), &IdxVec[0],
1030                                         IdxVec.size());
1031
1032    const MCExpr *Base = LowerConstant(CE->getOperand(0), AP);
1033    if (Offset == 0)
1034      return Base;
1035
1036    // Truncate/sext the offset to the pointer size.
1037    if (TD.getPointerSizeInBits() != 64) {
1038      int SExtAmount = 64-TD.getPointerSizeInBits();
1039      Offset = (Offset << SExtAmount) >> SExtAmount;
1040    }
1041
1042    return MCBinaryExpr::CreateAdd(Base, MCConstantExpr::Create(Offset, Ctx),
1043                                   Ctx);
1044  }
1045
1046  case Instruction::Trunc:
1047    // We emit the value and depend on the assembler to truncate the generated
1048    // expression properly.  This is important for differences between
1049    // blockaddress labels.  Since the two labels are in the same function, it
1050    // is reasonable to treat their delta as a 32-bit value.
1051    // FALL THROUGH.
1052  case Instruction::BitCast:
1053    return LowerConstant(CE->getOperand(0), AP);
1054
1055  case Instruction::IntToPtr: {
1056    const TargetData &TD = *AP.TM.getTargetData();
1057    // Handle casts to pointers by changing them into casts to the appropriate
1058    // integer type.  This promotes constant folding and simplifies this code.
1059    Constant *Op = CE->getOperand(0);
1060    Op = ConstantExpr::getIntegerCast(Op, TD.getIntPtrType(CV->getContext()),
1061                                      false/*ZExt*/);
1062    return LowerConstant(Op, AP);
1063  }
1064
1065  case Instruction::PtrToInt: {
1066    const TargetData &TD = *AP.TM.getTargetData();
1067    // Support only foldable casts to/from pointers that can be eliminated by
1068    // changing the pointer to the appropriately sized integer type.
1069    Constant *Op = CE->getOperand(0);
1070    const Type *Ty = CE->getType();
1071
1072    const MCExpr *OpExpr = LowerConstant(Op, AP);
1073
1074    // We can emit the pointer value into this slot if the slot is an
1075    // integer slot equal to the size of the pointer.
1076    if (TD.getTypeAllocSize(Ty) == TD.getTypeAllocSize(Op->getType()))
1077      return OpExpr;
1078
1079    // Otherwise the pointer is smaller than the resultant integer, mask off
1080    // the high bits so we are sure to get a proper truncation if the input is
1081    // a constant expr.
1082    unsigned InBits = TD.getTypeAllocSizeInBits(Op->getType());
1083    const MCExpr *MaskExpr = MCConstantExpr::Create(~0ULL >> (64-InBits), Ctx);
1084    return MCBinaryExpr::CreateAnd(OpExpr, MaskExpr, Ctx);
1085  }
1086
1087  // The MC library also has a right-shift operator, but it isn't consistently
1088  // signed or unsigned between different targets.
1089  case Instruction::Add:
1090  case Instruction::Sub:
1091  case Instruction::Mul:
1092  case Instruction::SDiv:
1093  case Instruction::SRem:
1094  case Instruction::Shl:
1095  case Instruction::And:
1096  case Instruction::Or:
1097  case Instruction::Xor: {
1098    const MCExpr *LHS = LowerConstant(CE->getOperand(0), AP);
1099    const MCExpr *RHS = LowerConstant(CE->getOperand(1), AP);
1100    switch (CE->getOpcode()) {
1101    default: llvm_unreachable("Unknown binary operator constant cast expr");
1102    case Instruction::Add: return MCBinaryExpr::CreateAdd(LHS, RHS, Ctx);
1103    case Instruction::Sub: return MCBinaryExpr::CreateSub(LHS, RHS, Ctx);
1104    case Instruction::Mul: return MCBinaryExpr::CreateMul(LHS, RHS, Ctx);
1105    case Instruction::SDiv: return MCBinaryExpr::CreateDiv(LHS, RHS, Ctx);
1106    case Instruction::SRem: return MCBinaryExpr::CreateMod(LHS, RHS, Ctx);
1107    case Instruction::Shl: return MCBinaryExpr::CreateShl(LHS, RHS, Ctx);
1108    case Instruction::And: return MCBinaryExpr::CreateAnd(LHS, RHS, Ctx);
1109    case Instruction::Or:  return MCBinaryExpr::CreateOr (LHS, RHS, Ctx);
1110    case Instruction::Xor: return MCBinaryExpr::CreateXor(LHS, RHS, Ctx);
1111    }
1112  }
1113  }
1114}
1115
1116static void EmitGlobalConstantArray(const ConstantArray *CA, unsigned AddrSpace,
1117                                    AsmPrinter &AP) {
1118  if (AddrSpace != 0 || !CA->isString()) {
1119    // Not a string.  Print the values in successive locations
1120    for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1121      AP.EmitGlobalConstant(CA->getOperand(i), AddrSpace);
1122    return;
1123  }
1124
1125  // Otherwise, it can be emitted as .ascii.
1126  SmallVector<char, 128> TmpVec;
1127  TmpVec.reserve(CA->getNumOperands());
1128  for (unsigned i = 0, e = CA->getNumOperands(); i != e; ++i)
1129    TmpVec.push_back(cast<ConstantInt>(CA->getOperand(i))->getZExtValue());
1130
1131  AP.OutStreamer.EmitBytes(StringRef(TmpVec.data(), TmpVec.size()), AddrSpace);
1132}
1133
1134static void EmitGlobalConstantVector(const ConstantVector *CV,
1135                                     unsigned AddrSpace, AsmPrinter &AP) {
1136  for (unsigned i = 0, e = CV->getType()->getNumElements(); i != e; ++i)
1137    AP.EmitGlobalConstant(CV->getOperand(i), AddrSpace);
1138}
1139
1140static void EmitGlobalConstantStruct(const ConstantStruct *CS,
1141                                     unsigned AddrSpace, AsmPrinter &AP) {
1142  // Print the fields in successive locations. Pad to align if needed!
1143  const TargetData *TD = AP.TM.getTargetData();
1144  unsigned Size = TD->getTypeAllocSize(CS->getType());
1145  const StructLayout *Layout = TD->getStructLayout(CS->getType());
1146  uint64_t SizeSoFar = 0;
1147  for (unsigned i = 0, e = CS->getNumOperands(); i != e; ++i) {
1148    const Constant *Field = CS->getOperand(i);
1149
1150    // Check if padding is needed and insert one or more 0s.
1151    uint64_t FieldSize = TD->getTypeAllocSize(Field->getType());
1152    uint64_t PadSize = ((i == e-1 ? Size : Layout->getElementOffset(i+1))
1153                        - Layout->getElementOffset(i)) - FieldSize;
1154    SizeSoFar += FieldSize + PadSize;
1155
1156    // Now print the actual field value.
1157    AP.EmitGlobalConstant(Field, AddrSpace);
1158
1159    // Insert padding - this may include padding to increase the size of the
1160    // current field up to the ABI size (if the struct is not packed) as well
1161    // as padding to ensure that the next field starts at the right offset.
1162    AP.OutStreamer.EmitZeros(PadSize, AddrSpace);
1163  }
1164  assert(SizeSoFar == Layout->getSizeInBytes() &&
1165         "Layout of constant struct may be incorrect!");
1166}
1167
1168static void EmitGlobalConstantUnion(const ConstantUnion *CU,
1169                                    unsigned AddrSpace, AsmPrinter &AP) {
1170  const TargetData *TD = AP.TM.getTargetData();
1171  unsigned Size = TD->getTypeAllocSize(CU->getType());
1172
1173  const Constant *Contents = CU->getOperand(0);
1174  unsigned FilledSize = TD->getTypeAllocSize(Contents->getType());
1175
1176  // Print the actually filled part
1177  AP.EmitGlobalConstant(Contents, AddrSpace);
1178
1179  // And pad with enough zeroes
1180  AP.OutStreamer.EmitZeros(Size-FilledSize, AddrSpace);
1181}
1182
1183static void EmitGlobalConstantFP(const ConstantFP *CFP, unsigned AddrSpace,
1184                                 AsmPrinter &AP) {
1185  // FP Constants are printed as integer constants to avoid losing
1186  // precision.
1187  if (CFP->getType()->isDoubleTy()) {
1188    if (AP.VerboseAsm) {
1189      double Val = CFP->getValueAPF().convertToDouble();
1190      AP.OutStreamer.GetCommentOS() << "double " << Val << '\n';
1191    }
1192
1193    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1194    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1195    return;
1196  }
1197
1198  if (CFP->getType()->isFloatTy()) {
1199    if (AP.VerboseAsm) {
1200      float Val = CFP->getValueAPF().convertToFloat();
1201      AP.OutStreamer.GetCommentOS() << "float " << Val << '\n';
1202    }
1203    uint64_t Val = CFP->getValueAPF().bitcastToAPInt().getZExtValue();
1204    AP.OutStreamer.EmitIntValue(Val, 4, AddrSpace);
1205    return;
1206  }
1207
1208  if (CFP->getType()->isX86_FP80Ty()) {
1209    // all long double variants are printed as hex
1210    // api needed to prevent premature destruction
1211    APInt API = CFP->getValueAPF().bitcastToAPInt();
1212    const uint64_t *p = API.getRawData();
1213    if (AP.VerboseAsm) {
1214      // Convert to double so we can print the approximate val as a comment.
1215      APFloat DoubleVal = CFP->getValueAPF();
1216      bool ignored;
1217      DoubleVal.convert(APFloat::IEEEdouble, APFloat::rmNearestTiesToEven,
1218                        &ignored);
1219      AP.OutStreamer.GetCommentOS() << "x86_fp80 ~= "
1220        << DoubleVal.convertToDouble() << '\n';
1221    }
1222
1223    if (AP.TM.getTargetData()->isBigEndian()) {
1224      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1225      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1226    } else {
1227      AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1228      AP.OutStreamer.EmitIntValue(p[1], 2, AddrSpace);
1229    }
1230
1231    // Emit the tail padding for the long double.
1232    const TargetData &TD = *AP.TM.getTargetData();
1233    AP.OutStreamer.EmitZeros(TD.getTypeAllocSize(CFP->getType()) -
1234                             TD.getTypeStoreSize(CFP->getType()), AddrSpace);
1235    return;
1236  }
1237
1238  assert(CFP->getType()->isPPC_FP128Ty() &&
1239         "Floating point constant type not handled");
1240  // All long double variants are printed as hex api needed to prevent
1241  // premature destruction.
1242  APInt API = CFP->getValueAPF().bitcastToAPInt();
1243  const uint64_t *p = API.getRawData();
1244  if (AP.TM.getTargetData()->isBigEndian()) {
1245    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1246    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1247  } else {
1248    AP.OutStreamer.EmitIntValue(p[1], 8, AddrSpace);
1249    AP.OutStreamer.EmitIntValue(p[0], 8, AddrSpace);
1250  }
1251}
1252
1253static void EmitGlobalConstantLargeInt(const ConstantInt *CI,
1254                                       unsigned AddrSpace, AsmPrinter &AP) {
1255  const TargetData *TD = AP.TM.getTargetData();
1256  unsigned BitWidth = CI->getBitWidth();
1257  assert((BitWidth & 63) == 0 && "only support multiples of 64-bits");
1258
1259  // We don't expect assemblers to support integer data directives
1260  // for more than 64 bits, so we emit the data in at most 64-bit
1261  // quantities at a time.
1262  const uint64_t *RawData = CI->getValue().getRawData();
1263  for (unsigned i = 0, e = BitWidth / 64; i != e; ++i) {
1264    uint64_t Val = TD->isBigEndian() ? RawData[e - i - 1] : RawData[i];
1265    AP.OutStreamer.EmitIntValue(Val, 8, AddrSpace);
1266  }
1267}
1268
1269/// EmitGlobalConstant - Print a general LLVM constant to the .s file.
1270void AsmPrinter::EmitGlobalConstant(const Constant *CV, unsigned AddrSpace) {
1271  if (isa<ConstantAggregateZero>(CV) || isa<UndefValue>(CV)) {
1272    uint64_t Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1273    if (Size == 0) Size = 1; // An empty "_foo:" followed by a section is undef.
1274    return OutStreamer.EmitZeros(Size, AddrSpace);
1275  }
1276
1277  if (const ConstantInt *CI = dyn_cast<ConstantInt>(CV)) {
1278    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1279    switch (Size) {
1280    case 1:
1281    case 2:
1282    case 4:
1283    case 8:
1284      if (VerboseAsm)
1285        OutStreamer.GetCommentOS() << format("0x%llx\n", CI->getZExtValue());
1286      OutStreamer.EmitIntValue(CI->getZExtValue(), Size, AddrSpace);
1287      return;
1288    default:
1289      EmitGlobalConstantLargeInt(CI, AddrSpace, *this);
1290      return;
1291    }
1292  }
1293
1294  if (const ConstantArray *CVA = dyn_cast<ConstantArray>(CV))
1295    return EmitGlobalConstantArray(CVA, AddrSpace, *this);
1296
1297  if (const ConstantStruct *CVS = dyn_cast<ConstantStruct>(CV))
1298    return EmitGlobalConstantStruct(CVS, AddrSpace, *this);
1299
1300  if (const ConstantFP *CFP = dyn_cast<ConstantFP>(CV))
1301    return EmitGlobalConstantFP(CFP, AddrSpace, *this);
1302
1303  if (isa<ConstantPointerNull>(CV)) {
1304    unsigned Size = TM.getTargetData()->getTypeAllocSize(CV->getType());
1305    OutStreamer.EmitIntValue(0, Size, AddrSpace);
1306    return;
1307  }
1308
1309  if (const ConstantUnion *CVU = dyn_cast<ConstantUnion>(CV))
1310    return EmitGlobalConstantUnion(CVU, AddrSpace, *this);
1311
1312  if (const ConstantVector *V = dyn_cast<ConstantVector>(CV))
1313    return EmitGlobalConstantVector(V, AddrSpace, *this);
1314
1315  // Otherwise, it must be a ConstantExpr.  Lower it to an MCExpr, then emit it
1316  // thread the streamer with EmitValue.
1317  OutStreamer.EmitValue(LowerConstant(CV, *this),
1318                        TM.getTargetData()->getTypeAllocSize(CV->getType()),
1319                        AddrSpace);
1320}
1321
1322void AsmPrinter::EmitMachineConstantPoolValue(MachineConstantPoolValue *MCPV) {
1323  // Target doesn't support this yet!
1324  llvm_unreachable("Target does not support EmitMachineConstantPoolValue");
1325}
1326
1327/// PrintSpecial - Print information related to the specified machine instr
1328/// that is independent of the operand, and may be independent of the instr
1329/// itself.  This can be useful for portably encoding the comment character
1330/// or other bits of target-specific knowledge into the asmstrings.  The
1331/// syntax used is ${:comment}.  Targets can override this to add support
1332/// for their own strange codes.
1333void AsmPrinter::PrintSpecial(const MachineInstr *MI, raw_ostream &OS,
1334                              const char *Code) const {
1335  if (!strcmp(Code, "private")) {
1336    OS << MAI->getPrivateGlobalPrefix();
1337  } else if (!strcmp(Code, "comment")) {
1338    OS << MAI->getCommentString();
1339  } else if (!strcmp(Code, "uid")) {
1340    // Comparing the address of MI isn't sufficient, because machineinstrs may
1341    // be allocated to the same address across functions.
1342    const Function *ThisF = MI->getParent()->getParent()->getFunction();
1343
1344    // If this is a new LastFn instruction, bump the counter.
1345    if (LastMI != MI || LastFn != ThisF) {
1346      ++Counter;
1347      LastMI = MI;
1348      LastFn = ThisF;
1349    }
1350    OS << Counter;
1351  } else {
1352    std::string msg;
1353    raw_string_ostream Msg(msg);
1354    Msg << "Unknown special formatter '" << Code
1355         << "' for machine instr: " << *MI;
1356    llvm_report_error(Msg.str());
1357  }
1358}
1359
1360/// processDebugLoc - Processes the debug information of each machine
1361/// instruction's DebugLoc.
1362void AsmPrinter::processDebugLoc(const MachineInstr *MI,
1363                                 bool BeforePrintingInsn) {
1364  if (!MAI || !DW || !MAI->doesSupportDebugInformation()
1365      || !DW->ShouldEmitDwarfDebug())
1366    return;
1367
1368  if (!BeforePrintingInsn)
1369    // After printing instruction
1370    DW->EndScope(MI);
1371  else
1372    DW->BeginScope(MI);
1373}
1374
1375
1376/// printInlineAsm - This method formats and prints the specified machine
1377/// instruction that is an inline asm.
1378void AsmPrinter::printInlineAsm(const MachineInstr *MI) const {
1379  assert(MI->isInlineAsm() && "printInlineAsm only works on inline asms");
1380
1381  unsigned NumOperands = MI->getNumOperands();
1382
1383  // Count the number of register definitions to find the asm string.
1384  unsigned NumDefs = 0;
1385  for (; MI->getOperand(NumDefs).isReg() && MI->getOperand(NumDefs).isDef();
1386       ++NumDefs)
1387    assert(NumDefs != NumOperands-1 && "No asm string?");
1388
1389  assert(MI->getOperand(NumDefs).isSymbol() && "No asm string?");
1390
1391  // Disassemble the AsmStr, printing out the literal pieces, the operands, etc.
1392  const char *AsmStr = MI->getOperand(NumDefs).getSymbolName();
1393
1394  // If this asmstr is empty, just print the #APP/#NOAPP markers.
1395  // These are useful to see where empty asm's wound up.
1396  if (AsmStr[0] == 0) {
1397    if (!OutStreamer.hasRawTextSupport()) return;
1398
1399    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1400                            MAI->getInlineAsmStart());
1401    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1402                            MAI->getInlineAsmEnd());
1403    return;
1404  }
1405
1406  // Emit the #APP start marker.  This has to happen even if verbose-asm isn't
1407  // enabled, so we use EmitRawText.
1408  if (OutStreamer.hasRawTextSupport())
1409    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1410                            MAI->getInlineAsmStart());
1411
1412  // Emit the inline asm to a temporary string so we can emit it through
1413  // EmitInlineAsm.
1414#if 0
1415  SmallString<256> StringData;
1416  raw_svector_ostream O(StringData);
1417#endif
1418
1419  O << '\t';
1420
1421  // The variant of the current asmprinter.
1422  int AsmPrinterVariant = MAI->getAssemblerDialect();
1423
1424  int CurVariant = -1;            // The number of the {.|.|.} region we are in.
1425  const char *LastEmitted = AsmStr; // One past the last character emitted.
1426
1427  while (*LastEmitted) {
1428    switch (*LastEmitted) {
1429    default: {
1430      // Not a special case, emit the string section literally.
1431      const char *LiteralEnd = LastEmitted+1;
1432      while (*LiteralEnd && *LiteralEnd != '{' && *LiteralEnd != '|' &&
1433             *LiteralEnd != '}' && *LiteralEnd != '$' && *LiteralEnd != '\n')
1434        ++LiteralEnd;
1435      if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1436        O.write(LastEmitted, LiteralEnd-LastEmitted);
1437      LastEmitted = LiteralEnd;
1438      break;
1439    }
1440    case '\n':
1441      ++LastEmitted;   // Consume newline character.
1442      O << '\n';       // Indent code with newline.
1443      break;
1444    case '$': {
1445      ++LastEmitted;   // Consume '$' character.
1446      bool Done = true;
1447
1448      // Handle escapes.
1449      switch (*LastEmitted) {
1450      default: Done = false; break;
1451      case '$':     // $$ -> $
1452        if (CurVariant == -1 || CurVariant == AsmPrinterVariant)
1453          O << '$';
1454        ++LastEmitted;  // Consume second '$' character.
1455        break;
1456      case '(':             // $( -> same as GCC's { character.
1457        ++LastEmitted;      // Consume '(' character.
1458        if (CurVariant != -1) {
1459          llvm_report_error("Nested variants found in inline asm string: '"
1460                            + std::string(AsmStr) + "'");
1461        }
1462        CurVariant = 0;     // We're in the first variant now.
1463        break;
1464      case '|':
1465        ++LastEmitted;  // consume '|' character.
1466        if (CurVariant == -1)
1467          O << '|';       // this is gcc's behavior for | outside a variant
1468        else
1469          ++CurVariant;   // We're in the next variant.
1470        break;
1471      case ')':         // $) -> same as GCC's } char.
1472        ++LastEmitted;  // consume ')' character.
1473        if (CurVariant == -1)
1474          O << '}';     // this is gcc's behavior for } outside a variant
1475        else
1476          CurVariant = -1;
1477        break;
1478      }
1479      if (Done) break;
1480
1481      bool HasCurlyBraces = false;
1482      if (*LastEmitted == '{') {     // ${variable}
1483        ++LastEmitted;               // Consume '{' character.
1484        HasCurlyBraces = true;
1485      }
1486
1487      // If we have ${:foo}, then this is not a real operand reference, it is a
1488      // "magic" string reference, just like in .td files.  Arrange to call
1489      // PrintSpecial.
1490      if (HasCurlyBraces && *LastEmitted == ':') {
1491        ++LastEmitted;
1492        const char *StrStart = LastEmitted;
1493        const char *StrEnd = strchr(StrStart, '}');
1494        if (StrEnd == 0) {
1495          llvm_report_error("Unterminated ${:foo} operand in inline asm string: '"
1496                            + std::string(AsmStr) + "'");
1497        }
1498
1499        std::string Val(StrStart, StrEnd);
1500        PrintSpecial(MI, O, Val.c_str());
1501        LastEmitted = StrEnd+1;
1502        break;
1503      }
1504
1505      const char *IDStart = LastEmitted;
1506      char *IDEnd;
1507      errno = 0;
1508      long Val = strtol(IDStart, &IDEnd, 10); // We only accept numbers for IDs.
1509      if (!isdigit(*IDStart) || (Val == 0 && errno == EINVAL)) {
1510        llvm_report_error("Bad $ operand number in inline asm string: '"
1511                          + std::string(AsmStr) + "'");
1512      }
1513      LastEmitted = IDEnd;
1514
1515      char Modifier[2] = { 0, 0 };
1516
1517      if (HasCurlyBraces) {
1518        // If we have curly braces, check for a modifier character.  This
1519        // supports syntax like ${0:u}, which correspond to "%u0" in GCC asm.
1520        if (*LastEmitted == ':') {
1521          ++LastEmitted;    // Consume ':' character.
1522          if (*LastEmitted == 0) {
1523            llvm_report_error("Bad ${:} expression in inline asm string: '"
1524                              + std::string(AsmStr) + "'");
1525          }
1526
1527          Modifier[0] = *LastEmitted;
1528          ++LastEmitted;    // Consume modifier character.
1529        }
1530
1531        if (*LastEmitted != '}') {
1532          llvm_report_error("Bad ${} expression in inline asm string: '"
1533                            + std::string(AsmStr) + "'");
1534        }
1535        ++LastEmitted;    // Consume '}' character.
1536      }
1537
1538      if ((unsigned)Val >= NumOperands-1) {
1539        llvm_report_error("Invalid $ operand number in inline asm string: '"
1540                          + std::string(AsmStr) + "'");
1541      }
1542
1543      // Okay, we finally have a value number.  Ask the target to print this
1544      // operand!
1545      if (CurVariant == -1 || CurVariant == AsmPrinterVariant) {
1546        unsigned OpNo = 1;
1547
1548        bool Error = false;
1549
1550        // Scan to find the machine operand number for the operand.
1551        for (; Val; --Val) {
1552          if (OpNo >= MI->getNumOperands()) break;
1553          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1554          OpNo += InlineAsm::getNumOperandRegisters(OpFlags) + 1;
1555        }
1556
1557        if (OpNo >= MI->getNumOperands()) {
1558          Error = true;
1559        } else {
1560          unsigned OpFlags = MI->getOperand(OpNo).getImm();
1561          ++OpNo;  // Skip over the ID number.
1562
1563          if (Modifier[0] == 'l')  // labels are target independent
1564            O << *MI->getOperand(OpNo).getMBB()->getSymbol();
1565          else {
1566            AsmPrinter *AP = const_cast<AsmPrinter*>(this);
1567            if ((OpFlags & 7) == 4) {
1568              Error = AP->PrintAsmMemoryOperand(MI, OpNo, AsmPrinterVariant,
1569                                                Modifier[0] ? Modifier : 0);
1570            } else {
1571              Error = AP->PrintAsmOperand(MI, OpNo, AsmPrinterVariant,
1572                                          Modifier[0] ? Modifier : 0);
1573            }
1574          }
1575        }
1576        if (Error) {
1577          std::string msg;
1578          raw_string_ostream Msg(msg);
1579          Msg << "Invalid operand found in inline asm: '" << AsmStr << "'\n";
1580          MI->print(Msg);
1581          llvm_report_error(Msg.str());
1582        }
1583      }
1584      break;
1585    }
1586    }
1587  }
1588  O << "\n";
1589
1590#if 0
1591  EmitInlineAsm(O.str());
1592#endif
1593
1594  // Emit the #NOAPP end marker.  This has to happen even if verbose-asm isn't
1595  // enabled, so we use EmitRawText.
1596  if (OutStreamer.hasRawTextSupport())
1597    OutStreamer.EmitRawText(Twine("\t")+MAI->getCommentString()+
1598                            MAI->getInlineAsmEnd());
1599}
1600
1601/// printImplicitDef - This method prints the specified machine instruction
1602/// that is an implicit def.
1603void AsmPrinter::printImplicitDef(const MachineInstr *MI) const {
1604  if (!VerboseAsm) return;
1605  OutStreamer.AddComment(Twine("implicit-def: ") +
1606                         TRI->getName(MI->getOperand(0).getReg()));
1607  OutStreamer.AddBlankLine();
1608}
1609
1610void AsmPrinter::printKill(const MachineInstr *MI) const {
1611  if (!VerboseAsm) return;
1612  O.PadToColumn(MAI->getCommentColumn());
1613
1614  std::string Str = "kill:";
1615  for (unsigned n = 0, e = MI->getNumOperands(); n != e; ++n) {
1616    const MachineOperand &Op = MI->getOperand(n);
1617    assert(Op.isReg() && "KILL instruction must have only register operands");
1618    Str += ' ';
1619    Str += TRI->getName(Op.getReg());
1620    Str += (Op.isDef() ? "<def>" : "<kill>");
1621  }
1622  OutStreamer.AddComment(Str);
1623  OutStreamer.AddBlankLine();
1624}
1625
1626/// printLabel - This method prints a local label used by debug and
1627/// exception handling tables.
1628void AsmPrinter::printLabelInst(const MachineInstr *MI) const {
1629  OutStreamer.EmitLabel(MI->getOperand(0).getMCSymbol());
1630}
1631
1632/// PrintAsmOperand - Print the specified operand of MI, an INLINEASM
1633/// instruction, using the specified assembler variant.  Targets should
1634/// override this to format as appropriate.
1635bool AsmPrinter::PrintAsmOperand(const MachineInstr *MI, unsigned OpNo,
1636                                 unsigned AsmVariant, const char *ExtraCode) {
1637  // Target doesn't support this yet!
1638  return true;
1639}
1640
1641bool AsmPrinter::PrintAsmMemoryOperand(const MachineInstr *MI, unsigned OpNo,
1642                                       unsigned AsmVariant,
1643                                       const char *ExtraCode) {
1644  // Target doesn't support this yet!
1645  return true;
1646}
1647
1648MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BlockAddress *BA) const {
1649  return MMI->getAddrLabelSymbol(BA->getBasicBlock());
1650}
1651
1652MCSymbol *AsmPrinter::GetBlockAddressSymbol(const BasicBlock *BB) const {
1653  return MMI->getAddrLabelSymbol(BB);
1654}
1655
1656/// GetCPISymbol - Return the symbol for the specified constant pool entry.
1657MCSymbol *AsmPrinter::GetCPISymbol(unsigned CPID) const {
1658  return OutContext.GetOrCreateSymbol
1659    (Twine(MAI->getPrivateGlobalPrefix()) + "CPI" + Twine(getFunctionNumber())
1660     + "_" + Twine(CPID));
1661}
1662
1663/// GetJTISymbol - Return the symbol for the specified jump table entry.
1664MCSymbol *AsmPrinter::GetJTISymbol(unsigned JTID, bool isLinkerPrivate) const {
1665  return MF->getJTISymbol(JTID, OutContext, isLinkerPrivate);
1666}
1667
1668/// GetJTSetSymbol - Return the symbol for the specified jump table .set
1669/// FIXME: privatize to AsmPrinter.
1670MCSymbol *AsmPrinter::GetJTSetSymbol(unsigned UID, unsigned MBBID) const {
1671  return OutContext.GetOrCreateSymbol
1672  (Twine(MAI->getPrivateGlobalPrefix()) + Twine(getFunctionNumber()) + "_" +
1673   Twine(UID) + "_set_" + Twine(MBBID));
1674}
1675
1676/// GetSymbolWithGlobalValueBase - Return the MCSymbol for a symbol with
1677/// global value name as its base, with the specified suffix, and where the
1678/// symbol is forced to have private linkage if ForcePrivate is true.
1679MCSymbol *AsmPrinter::GetSymbolWithGlobalValueBase(const GlobalValue *GV,
1680                                                   StringRef Suffix,
1681                                                   bool ForcePrivate) const {
1682  SmallString<60> NameStr;
1683  Mang->getNameWithPrefix(NameStr, GV, ForcePrivate);
1684  NameStr.append(Suffix.begin(), Suffix.end());
1685  return OutContext.GetOrCreateSymbol(NameStr.str());
1686}
1687
1688/// GetExternalSymbolSymbol - Return the MCSymbol for the specified
1689/// ExternalSymbol.
1690MCSymbol *AsmPrinter::GetExternalSymbolSymbol(StringRef Sym) const {
1691  SmallString<60> NameStr;
1692  Mang->getNameWithPrefix(NameStr, Sym);
1693  return OutContext.GetOrCreateSymbol(NameStr.str());
1694}
1695
1696
1697
1698/// PrintParentLoopComment - Print comments about parent loops of this one.
1699static void PrintParentLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1700                                   unsigned FunctionNumber) {
1701  if (Loop == 0) return;
1702  PrintParentLoopComment(OS, Loop->getParentLoop(), FunctionNumber);
1703  OS.indent(Loop->getLoopDepth()*2)
1704    << "Parent Loop BB" << FunctionNumber << "_"
1705    << Loop->getHeader()->getNumber()
1706    << " Depth=" << Loop->getLoopDepth() << '\n';
1707}
1708
1709
1710/// PrintChildLoopComment - Print comments about child loops within
1711/// the loop for this basic block, with nesting.
1712static void PrintChildLoopComment(raw_ostream &OS, const MachineLoop *Loop,
1713                                  unsigned FunctionNumber) {
1714  // Add child loop information
1715  for (MachineLoop::iterator CL = Loop->begin(), E = Loop->end();CL != E; ++CL){
1716    OS.indent((*CL)->getLoopDepth()*2)
1717      << "Child Loop BB" << FunctionNumber << "_"
1718      << (*CL)->getHeader()->getNumber() << " Depth " << (*CL)->getLoopDepth()
1719      << '\n';
1720    PrintChildLoopComment(OS, *CL, FunctionNumber);
1721  }
1722}
1723
1724/// PrintBasicBlockLoopComments - Pretty-print comments for basic blocks.
1725static void PrintBasicBlockLoopComments(const MachineBasicBlock &MBB,
1726                                        const MachineLoopInfo *LI,
1727                                        const AsmPrinter &AP) {
1728  // Add loop depth information
1729  const MachineLoop *Loop = LI->getLoopFor(&MBB);
1730  if (Loop == 0) return;
1731
1732  MachineBasicBlock *Header = Loop->getHeader();
1733  assert(Header && "No header for loop");
1734
1735  // If this block is not a loop header, just print out what is the loop header
1736  // and return.
1737  if (Header != &MBB) {
1738    AP.OutStreamer.AddComment("  in Loop: Header=BB" +
1739                              Twine(AP.getFunctionNumber())+"_" +
1740                              Twine(Loop->getHeader()->getNumber())+
1741                              " Depth="+Twine(Loop->getLoopDepth()));
1742    return;
1743  }
1744
1745  // Otherwise, it is a loop header.  Print out information about child and
1746  // parent loops.
1747  raw_ostream &OS = AP.OutStreamer.GetCommentOS();
1748
1749  PrintParentLoopComment(OS, Loop->getParentLoop(), AP.getFunctionNumber());
1750
1751  OS << "=>";
1752  OS.indent(Loop->getLoopDepth()*2-2);
1753
1754  OS << "This ";
1755  if (Loop->empty())
1756    OS << "Inner ";
1757  OS << "Loop Header: Depth=" + Twine(Loop->getLoopDepth()) << '\n';
1758
1759  PrintChildLoopComment(OS, Loop, AP.getFunctionNumber());
1760}
1761
1762
1763/// EmitBasicBlockStart - This method prints the label for the specified
1764/// MachineBasicBlock, an alignment (if present) and a comment describing
1765/// it if appropriate.
1766void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock *MBB) const {
1767  // Emit an alignment directive for this block, if needed.
1768  if (unsigned Align = MBB->getAlignment())
1769    EmitAlignment(Log2_32(Align));
1770
1771  // If the block has its address taken, emit any labels that were used to
1772  // reference the block.  It is possible that there is more than one label
1773  // here, because multiple LLVM BB's may have been RAUW'd to this block after
1774  // the references were generated.
1775  if (MBB->hasAddressTaken()) {
1776    const BasicBlock *BB = MBB->getBasicBlock();
1777    if (VerboseAsm)
1778      OutStreamer.AddComment("Block address taken");
1779
1780    std::vector<MCSymbol*> Syms = MMI->getAddrLabelSymbolToEmit(BB);
1781
1782    for (unsigned i = 0, e = Syms.size(); i != e; ++i)
1783      OutStreamer.EmitLabel(Syms[i]);
1784  }
1785
1786  // Print the main label for the block.
1787  if (MBB->pred_empty() || isBlockOnlyReachableByFallthrough(MBB)) {
1788    if (VerboseAsm && OutStreamer.hasRawTextSupport()) {
1789      if (const BasicBlock *BB = MBB->getBasicBlock())
1790        if (BB->hasName())
1791          OutStreamer.AddComment("%" + BB->getName());
1792
1793      PrintBasicBlockLoopComments(*MBB, LI, *this);
1794
1795      // NOTE: Want this comment at start of line, don't emit with AddComment.
1796      OutStreamer.EmitRawText(Twine(MAI->getCommentString()) + " BB#" +
1797                              Twine(MBB->getNumber()) + ":");
1798    }
1799  } else {
1800    if (VerboseAsm) {
1801      if (const BasicBlock *BB = MBB->getBasicBlock())
1802        if (BB->hasName())
1803          OutStreamer.AddComment("%" + BB->getName());
1804      PrintBasicBlockLoopComments(*MBB, LI, *this);
1805    }
1806
1807    OutStreamer.EmitLabel(MBB->getSymbol());
1808  }
1809}
1810
1811void AsmPrinter::EmitVisibility(MCSymbol *Sym, unsigned Visibility) const {
1812  MCSymbolAttr Attr = MCSA_Invalid;
1813
1814  switch (Visibility) {
1815  default: break;
1816  case GlobalValue::HiddenVisibility:
1817    Attr = MAI->getHiddenVisibilityAttr();
1818    break;
1819  case GlobalValue::ProtectedVisibility:
1820    Attr = MAI->getProtectedVisibilityAttr();
1821    break;
1822  }
1823
1824  if (Attr != MCSA_Invalid)
1825    OutStreamer.EmitSymbolAttribute(Sym, Attr);
1826}
1827
1828void AsmPrinter::printOffset(int64_t Offset, raw_ostream &OS) const {
1829  if (Offset > 0)
1830    OS << '+' << Offset;
1831  else if (Offset < 0)
1832    OS << Offset;
1833}
1834
1835/// isBlockOnlyReachableByFallthough - Return true if the basic block has
1836/// exactly one predecessor and the control transfer mechanism between
1837/// the predecessor and this block is a fall-through.
1838bool AsmPrinter::isBlockOnlyReachableByFallthrough(const MachineBasicBlock *MBB)
1839    const {
1840  // If this is a landing pad, it isn't a fall through.  If it has no preds,
1841  // then nothing falls through to it.
1842  if (MBB->isLandingPad() || MBB->pred_empty())
1843    return false;
1844
1845  // If there isn't exactly one predecessor, it can't be a fall through.
1846  MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(), PI2 = PI;
1847  ++PI2;
1848  if (PI2 != MBB->pred_end())
1849    return false;
1850
1851  // The predecessor has to be immediately before this block.
1852  const MachineBasicBlock *Pred = *PI;
1853
1854  if (!Pred->isLayoutSuccessor(MBB))
1855    return false;
1856
1857  // If the block is completely empty, then it definitely does fall through.
1858  if (Pred->empty())
1859    return true;
1860
1861  // Otherwise, check the last instruction.
1862  const MachineInstr &LastInst = Pred->back();
1863  return !LastInst.getDesc().isBarrier();
1864}
1865
1866
1867
1868GCMetadataPrinter *AsmPrinter::GetOrCreateGCPrinter(GCStrategy *S) {
1869  if (!S->usesMetadata())
1870    return 0;
1871
1872  gcp_iterator GCPI = GCMetadataPrinters.find(S);
1873  if (GCPI != GCMetadataPrinters.end())
1874    return GCPI->second;
1875
1876  const char *Name = S->getName().c_str();
1877
1878  for (GCMetadataPrinterRegistry::iterator
1879         I = GCMetadataPrinterRegistry::begin(),
1880         E = GCMetadataPrinterRegistry::end(); I != E; ++I)
1881    if (strcmp(Name, I->getName()) == 0) {
1882      GCMetadataPrinter *GMP = I->instantiate();
1883      GMP->S = S;
1884      GCMetadataPrinters.insert(std::make_pair(S, GMP));
1885      return GMP;
1886    }
1887
1888  llvm_report_error("no GCMetadataPrinter registered for GC: " + Twine(Name));
1889  return 0;
1890}
1891
1892